U.S. patent application number 15/374328 was filed with the patent office on 2017-07-20 for device and method for filling an aneurysm or body cavity.
The applicant listed for this patent is Interventco, LLC. Invention is credited to Chet R. Rees.
Application Number | 20170202558 15/374328 |
Document ID | / |
Family ID | 49513146 |
Filed Date | 2017-07-20 |
United States Patent
Application |
20170202558 |
Kind Code |
A1 |
Rees; Chet R. |
July 20, 2017 |
DEVICE AND METHOD FOR FILLING AN ANEURYSM OR BODY CAVITY
Abstract
The invention relates generally to embolic agents and embolic
delivery systems more specifically it relates to a device and
method for filling of aneurysm or body cavity. In various
embodiments, segmented and monolithic embolic agents provide the
operator with the ability to select and detach the length of
embolic agent, either extracorporeally or intracorporeally as
desired by the operator, for implantation into the aneurysm or body
cavity. Linking elements and detachment elements may be utilized by
the operator to connect and detach variable lengths of embolic
agents either extracorporeally or intracorporeally utilizing
electrolytic, chemical, and mechanical detachment mechanisms.
Embolic delivery systems are disclosed providing for constant and
steady propulsion of the embolic agent.
Inventors: |
Rees; Chet R.; (Dallas,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Interventco, LLC |
Dallas |
TX |
US |
|
|
Family ID: |
49513146 |
Appl. No.: |
15/374328 |
Filed: |
December 9, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13887777 |
May 6, 2013 |
9549740 |
|
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15374328 |
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61642762 |
May 4, 2012 |
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61660930 |
Jun 18, 2012 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 2017/12068
20130101; A61B 2017/12054 20130101; A61B 17/12022 20130101; A61B
17/12113 20130101; A61B 2017/12059 20130101; A61B 2017/1205
20130101; A61B 17/12163 20130101; A61B 2017/12081 20130101; A61B
17/1215 20130101; A61B 17/1214 20130101; A61B 2017/12095 20130101;
A61B 17/12154 20130101; A61B 2017/12063 20130101 |
International
Class: |
A61B 17/12 20060101
A61B017/12 |
Claims
1. An embolic agent apparatus, comprising: an embolic agent with at
least two or more segments, each segment of the embolic agent
having a proximal end, a middle portion, and a distal end; and, a
detachment element separating each embolic agent segment operable
to provide a detachment site selectable by the operator.
2. The apparatus of claim 1 further comprising: a linking element
operable to connect the proximal end of the embolic agent to a
detachment element associated with the distal end of a pusher
element operable to allow the operator to orient the embolic agent
with bi-directional motion.
3. The apparatus of claim 1 further comprising: a linking element
operable to link the proximal end of the embolic agent with the
distal end of the detachment element operable to advance the
detachment site of the embolic agent intracorporeally.
4. The apparatus of claim 1 wherein the embolic agent includes at
least one node located between the distal and proximate ends of at
least one segment of the embolic agent.
5. The apparatus of claim 1 wherein the embolic agent includes at
least one notch located between the distal and proximate ends of at
least one segment of the embolic agent.
6. The apparatus of claim 1 wherein the detachment element is
selected from the group consisting of a mechanical detachment
element, an electrolytic detachment element, a bi-directional
locking element, a heat sensitive adhesive, a heat deformable
metal, a corrodible metal, a dissolvable metal, and a dissolvable
polymer.
7. The apparatus of claim 1 wherein the embolic agent is selected
from the group consisting of a monofilament, a multifilament, a
helical wire, an encapsulated wire, a coated helical wire, a
chemically dissolvable polymer, an electrolytically corrodible
wire, a polymer, a metal wire, a polyglycolide, a polylactide, a
poly L-lactide, a poly DL-lactide, a poly-caprolactone, and a
copolymer.
8. The apparatus of claim 1 wherein at least one segment of the
embolic agent includes a removable seal.
9. The apparatus of claim 1 wherein the embolic agent further
comprises: a wire within the body of the embolic agent capable of
conducting electrical current.
10. The apparatus of claim 1 wherein the embolic agent further
comprises: a traction element located on a surface of the embolic
agent.
11. The apparatus of claim 1 further comprising: a linking element
with an attachment pin and the linking element positioned between
the embolic agent and the detachment element.
12. The apparatus of claim 11 wherein the linking element includes
a traction element applied to the attachment pin wherein the
traction element is selected from the group consisting of a barb, a
ridge, an attachment pin, a curved attachment pin, a frictional
roughness, and a threaded connection.
13. The apparatus of claim 1 wherein the detachment element is one
selected from the group consisting of an adhesive, a sealant, a
chemically corrodible polymer, an electrolytically corrodible
metal, a polymer, polyglycolide, a polylactide, a poly L-lactide, a
poly DL-lactide, a poly-caprolactone, and a copolymer.
14. The apparatus of claim 1 wherein the detachment element or
embolic agent is modified by an embolic detachment tool selected
from the group consisting of a spark generator, a heat gun, a
sander, a shaper, a wire stripper, a dissolution chamber, a swage
tool, an adhesive, a heat chamber, a scissor or a blade.
15. The apparatus of claim 1 wherein the comprising: a catheter for
guiding the embolic agent to the target tissue wherein the catheter
includes an electrical current conducting wire secured within the
wall of the catheter up to the catheter tip, operable to allow the
operator to place the tip of the catheter at the desired detachment
element and electrolytically detach the embolic agent
intracorporeally.
16. The apparatus of claim 1 wherein the comprising: a catheter for
guiding the embolic agent to the target tissue wherein the catheter
delivers a solvent to the selected detachment element, operable to
allow the operator to place the tip of the catheter at the desired
detachment element and chemically detach the embolic agent
intracorporeally.
17. The apparatus of claim 1, wherein the embolic agent further
comprises a thermally reactive wire incorporated into the embolic
agent wherein the thermal wire includes shape memory such that the
embolic agent is substantially linear in the extracorporeal
environment and upon introduction into the intracorporeal
environment at elevated temperature the embolic agent assumes a
complex memory shape.
18. A catheter apparatus, comprising: a lumen and a wall forming a
tube structure with a proximal end, a middle portion and a distal
end; at least one wire encapsulated within the wall portion capable
of conducting electricity; and, a contact attached to the proximal
end of the tube and a contact attached to the distal end of the
tube so as to provide electrical energy to an embolic agent, a
detachment element or the local ionic medium.
19. An embolic delivery system, comprising: a drive pulley attached
to a drive shaft, a timing pulley and a feeder roller attached to a
pulley shaft; a catheter or embolic agent oriented between at least
two feeder rollers; and, a timing belt in mechanical communication
with the drive pulley and timing pulley operable to
bi-directionally move the embolic agent toward a target tissue.
20. The apparatus of claim 19 wherein at least one feeder roller
includes a groove around its circumference to assist in feeding and
providing traction between the feeder roller and the catheter or
embolic agent.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 13/887,777, filed May 6, 2013 which claims the
benefit of U.S. provisional patent application Ser. No. 61/642,762,
filed on May 4, 2012 and application Ser. No. 13/887,777 claims the
benefit of provisional patent application Ser. No. 61/660,930,
filed on Jun. 18, 2012, which are all hereby incorporated by
reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates generally to embolic materials
and more specifically it relates to a device and method for filling
of an aneurysm or body cavity. The purpose of this invention is to
provide a device and method for filling of a small or large
aneurysm or other body cavity with material to prevent flow of
blood or bodily fluids and promote blood clot or scarring in the
tissues to prevent undesirable conditions such as bleeding or fluid
leakage.
BRIEF SUMMARY OF THE INVENTION
[0003] The invention generally relates to an embolic material and
method for its delivery into the body. The elements of the
invention in the various described embodiments may include an
introducer sheath, an introducer catheter, a microcatheter, an
embolic agent, a linking element, a detachment element, an embolic
delivery apparatus, an embolic containment apparatus, a guide wire,
a pusher element, traction elements, a stopcock, a side port
adaptor, embolic detachment tools, and in certain environments an
endograft or stent. The operator selects the elements of the
invention as necessary to perform the procedure as may be
required.
[0004] In one embodiment, the invention comprises a device and
method for filling of a small or large aneurysm or other body
cavity with material to prevent flow of blood or bodily fluids and
promote blood clot or scarring in the tissues to prevent
undesirable conditions such as bleeding or fluid leakage. In one
embodiment, the invention comprises a device and method for filling
of an aneurysm or body cavity that may be used for many sizes of
aneurysm or cavity, including very large ones that may be difficult
or impossible to treat with other means or with conventional
embolic agents.
[0005] In one embodiment, the invention comprises a device and
method for filling of an aneurysm or body cavity that provides
rapid filling of the aneurysm or cavity that might otherwise take
substantially more time to fill or to prevent flow of body fluids
or blood using other means. In one embodiment, the invention
comprises a device and method for filling of an aneurysm or body
cavity with a high degree of safety due to small instrument sizes
and use of embolic materials that are biocompatible and may be
accurately delivered to target tissue without inadvertent delivery
to non-target tissues. Smaller diameters may be possible due to the
longer lengths of embolic agent possible with this invention,
resulting in great volume despite small diameter.
[0006] In one embodiment, the invention comprises a mechanical
and/or hydraulic means of advancement of embolic agent(s) through
introducer catheters that provide more rapid and controlled
deliveries that are not currently possible with current
conventional delivery means and to enable the advancement of very
flexible embolic agents that might be difficult to push manually
due to kinking. An object of this invention is to provide such a
delivery means to advance a very long single embolic agent with
speed and control and another object of other embodiments of this
invention provide a means for very rapid and controlled delivery
and advancement of a great plurality of shorter or more
conventionally proportioned embolic agents in order to provide a
great bulk of embolic material in their summation.
[0007] In one embodiment, the invention comprises a means of
providing a very long strand of embolic agent which may be reduced
in its length during the operative procedure using safe and
effective means, giving the operator flexibility to utilize the
advantages of a very long single embolic agent while also having
the advantage of tailoring the length to a very specific desired
length, with the determination of the desired length being possible
after the procedure has already begun and considerable length of
embolic material has already been deployed into the affected
tissues.
[0008] In one embodiment, the invention comprises an electrolytic
method of detaching and shortening the embolic agent during the
procedure at one of many possible locations along the embolic agent
instead of being limited to one specific detachment location or
point as with current conventional electrolytic agents. In one
embodiment, the invention comprises an introducer catheter with
electrical means to facilitate detachment or shortening of the
embolic agent at or near the tip of the introducer catheter deep
within the body of the subject in.
[0009] In one embodiment, the invention provides precision control
of the position of the embolic agent deep within the body of the
subject by manipulation of attached parts accessible to the
operators hands extra-corporeally, with ability to advance or
retract until the time of detachment. In one embodiment, the
invention comprises embolic agents that are modifiable by the
operator to facilitate objectives of determination of total length
and location of detachment. In one embodiment, the invention
provides the means to enable electrolytic methods with greater
utility than other known systems by being applicable to
variable-length embolic agents and also directed to a specific
detachment area. In one embodiment, the invention comprises means
to enhance the utility of existing mechanical detachment
configurations to be compatible with a variable-length embolic
agent.
[0010] In this respect, before explaining the invention in detail,
it is to be understood that the invention is not limited in its
application to the details of construction or to the arrangements
of the components set forth in the following description or
illustrated in the drawings. The invention is capable of other
embodiments and of being practiced and carried out in various ways.
Also, it is to be understood that the phraseology and terminology
employed herein are for the purpose of the description and should
not be regarded as limiting. To the accomplishment of the above and
related objects, this invention may be embodied in the form
illustrated in the accompanying drawings, attention being called to
the fact, however, that the drawings are illustrative only, and
that changes may be made in the specific construction illustrated
and described within the scope of this application.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Various other objects, features and attendant advantages of
the present invention will become fully appreciated as the same
becomes better understood when considered in conjunction with the
accompanying drawings, in which like reference characters designate
the same or similar parts throughout the several views, and
wherein:
[0012] FIGS. 1A-C are simplified block diagrams in the front view
illustrating the overall elements for embolization in one
embodiment of the present invention;
[0013] FIGS. 1D-L are schematic representations of different
categories of detachment systems including conventional and
novel;
[0014] FIGS. 1M-N are schematic demonstrations of the limitations
of conventional systems for treatment of large cavities, and the
advantages of the novel systems disclosed herein;
[0015] depict various novel embolic agents according to the various
embodiments of the disclosed invention;
[0016] FIGS. 2A-S illustrate different types of novel embolic
agents in various embodiments of the disclosed invention;
[0017] FIGS. 3A-J depict various connection and delivery
configurations of the embolic agents and catheter embodiments of
the disclosed invention;
[0018] FIGS. 4A-C show threaded embodiments of the novel embolic
agents disclosed herein;
[0019] FIGS. 5A-M depict various embodiments of the novel embolic
agents with radiomarkers as disclosed herein and which may be sized
and detached intra-corporeally as disclosed herein;
[0020] FIGS. 6A-Y show further embodiments of the novel embolic
agents which may be sized and detached intra-corporeally using
electrolytic means as disclosed herein;
[0021] FIGS. 7A-8R depict various embodiments of novel embolic
agents and apparatus and means for detaching embolic agents using
predominantly mechanical or hydraulic means;
[0022] FIGS. 9A-G depict novel linking elements and their use to
provide for shortening and detachment of embolic agents;
[0023] FIG. 10A show an embodiment of a novel chemical embolic
agent detachment system as disclosed herein;
[0024] FIG. 11A depicts various embodiments of conventional
mechanical detachment elements which may be employed in novel
manner using linking elements and detachment mechanisms as
described herein;
[0025] FIGS. 11B-C heat sensitive glue detachment mechanism adapted
in novel manner with linking element to provide for ability to
shorten embolic agent or choose detachment point;
[0026] FIGS. 12A-H depict various embodiments of novel catheters
containing electrical elements comprising two electrodes which are
utilized in conjunction with the embolic agents and embolic
delivery systems to provide for electrolytic detachment as
described herein;
[0027] FIG. 12I depicts a novel catheter containing electrical
elements comprising two electrodes and embolic agents whereby
non-electrolytic electrical means provide detachment of embolic
agent;
[0028] FIG. 12J depicts various embodiments of embolic agents
useful to some embodiments of the delivery system as described
herein;
[0029] FIGS. 13A-F depict various embodiments of novel introducer
catheters containing electrical elements comprising one electrode
which are utilized in conjunction with the embolic agents and
embolic delivery systems described herein;
[0030] FIGS. 14A-B depict various embodiments of variations of use
of electrical systems to provide detachment as described
herein;
[0031] FIGS. 15A-B depict various embodiments of venting catheters
which are utilized in conjunction with the embolic agents and
embolic delivery systems described herein;
[0032] FIGS. 16A-17 show an embodiment of a novel embolic delivery
system propelling the embolic agent using feeder wheels or belts as
described herein;
[0033] FIGS. 18A-M show various embodiments of traction elements
which may be formed or fashioned on to or within embolic agents as
described herein;
[0034] FIGS. 19A-E and FIGS. 20A-H depict various embodiments of
novel traction elements as described herein;
[0035] FIGS. 21A-F depict various embodiments of novel traction
elements and pusher elements as described herein;
[0036] FIGS. 22A-H depict various embodiments of embolic delivery
systems that utilize a principle of an attached flexible member
such as a string or filament or tape that may be pulled to force an
embolic agent through a catheter and then are stripped away from
the agent in a running manner, as disclosed in various embodiments
of the invention;
[0037] FIGS. 23A-I show various embodiments of novel embolic
delivery systems that use bidirectional linear motion elements
combined with traction elements to provide uni-directional linear
motion of embolic agents as described herein;
[0038] FIGS. 24A-G depicts embodiments of a novel embolic delivery
system that combines a linear feeding mechanism with a revolving
mechanism to provide rapid sequential delivery of a plurality of
embolic agents of short or medium length as described herein;
[0039] FIGS. 25A-C depict embodiments of a novel embolic delivery
system using a non-revolving mechanism to provide rapid sequential
delivery of a plurality of embolic agents of short or medium length
as described herein;
[0040] FIGS. 26A-G depict various embodiments of tools providing
for modification of an embolic agent intra-procedurally as
described herein;
[0041] FIG. 27A-B depict embodiments of introducer elements and
adaptors which may be used in connection with invention disclosed
herein;
[0042] FIGS. 28A-D depict various embodiments of novel embolic
agents with shape memory features useful to some embodiments of
delivery system as described herein.
DETAILED DESCRIPTION OF THE INVENTION
[0043] Before proceeding with a detailed description of the
invention, some commonly used terms will be defined to aid the
reader in the understanding and practice of the invention disclosed
herein.
[0044] The introducer sheath is a hollow tube of semi-rigid
material with a thin wall. It permits introduction of other
elements described below into the body. The other elements, such as
the introducer catheter, may pass through the lumen, or hollow
core, of the introducer sheath. The tip of the introducer sheath
will usually be positioned inside the body, such as in the artery
in FIG. 1, while the proximal end will usually be outside the body.
Once it is in position, it may be left in place for most of the
procedure, and thus provides a channel for passage of instruments
from the outside to the inside of the body. Several introducer
sheaths may be in place at one time, and some may be used for
passage of instruments that are not part of this invention, as well
as for instruments composing this invention. Introducer sheaths are
conventional elements known in the art. An introducer catheter may
be used without an introducer sheath in some instances.
[0045] The introducer catheter is a hollow shaft of semi-rigid
material with a thin wall, but is generally longer in length than
an introducer sheath and often smaller in caliber so that it can
fit co-axially inside an introducer sheath. It may be manipulated
by a user or operator into the desired part of the body, often
under fluoroscopic imaging for guidance. In FIG. 1 it is seen to
have its distal tip inside the body in an aortic aneurysm, and can
be seen to be in close proximity and adjacent to the endograft
inside the body aneurysm, but does not pass inside the hollow
endograft. It may be passed over a guide wire for more control, and
to facilitate the desired placement. The introducer catheter may be
used to pass the embolic agent, such as a long filament, from
outside the body, into the body where treatment is needed. Although
the introducer catheter may enter the body through the introducer
sheath, it may also be introduced through the tissues without the
introducer sheath using means well known in the art. Introducer
catheters are conventional elements commonly used in the art for
many purposes including the introduction of embolic agents. Novel
variations are described in this invention, including introducer
catheters that provide elements and functions relating to
detachment of the embolic agents as described below, sometimes
including electrolytic mechanisms that are partially located within
the introducer catheter.
[0046] Embolic agents are used in conventional practice of the art,
often using conventional introducer sheaths and introducer
catheters. In this invention, novel embolic agents are described in
detail elsewhere herein. Various embodiments of novel embolic
agents are depicted. The embolic agents described in this invention
are solids, and longer in the longitudinal axis than in width, like
strings or wires or filaments of various lengths and widths and
shapes depicted in detail elsewhere herein. They may be flexible,
but have enough stiffness to be capable of being pushed by a pusher
element or embolic delivery system. In FIG. 1, a long, narrow
filamentous embolic agent is seen housed in an embolic containment
apparatus outside of the body, being pushed into an introducer
catheter by an embolic delivery system, and exiting the distal end
of the introducer catheter inside the body; in this example into an
aneurysm of the abdominal aorta where it kinks and folds into a
complex shape, thus filling much of the space within the aneurysm
cavity in the body. Many details and variations of embolic agents
comprise many of the novel aspects of this invention.
[0047] A novel linking element is used by the operator to modify
the manufacturer-supplied elements by linking, defined as
connecting linearly (i.e. "end-to-end"), other elements with a
non-detachable attachment as seen in FIGS. 1I and 1J. The linking
site is separate from the detachment site, and is not located on
the linking element. Usually the elements that are linked by the
linking element are the embolic agent (on its proximal aspect) to
the detachment element (on its distal aspect) with the result of
and end-to-end series of connected elements that may be advanced or
retracted in unison by operator-manipulation of the proximal aspect
of the proximal component, i.e. the pusher element. In this
invention linking elements are used in conjunction with detachment
elements to enable operator-controlled detachment of the embolic
agent from the pusher element. Although linking elements do not
detach, their function provides the operator with the novel ability
to apply the detachment element and pusher elements at the location
of their choice on the embolic agent, thereby enabling the novel
aspects of variable length as determined by operator after partial
completion of procedure when ideal final length becomes evident.
Concepts of linking elements are demonstrated in FIGS. 1D-1L.
[0048] Detachment elements are elements that provide a detachable
attachment between other elements arrayed end-to-end so that one
element, usually an embolic agent, may be positionally controlled
by operator manipulation of another element, usually the pusher
element, until the operator wishes to separate the detachment
element, or separate between two detachment elements which were
attached together, thereby separating the other two elements from
each other, such as the embolic agent from the pusher element.
There are many different embodiments of previously described
detachment elements, with several commercially available,
corresponding to configurations and limitations described in FIGS.
1D-F. The invention disclosed herein additionally describes
detachment elements with configurations and properties described
herein. At the time of manufacture the detachment elements in this
invention are non-detachably attached to the embolic agent and/or
the linking or pusher element depending on embodiment.
[0049] The embolic delivery systems described herein are machines
made of solid materials that can withstand wetness without losing
function, such as metal, plastic, and rubber or rubber-like
flexible compounds. They may also contain electrical components and
a motor with speed controls, and an electrical power source such as
battery. The system serves to drive the embolic agent to the target
tissue in the body. It may drive the embolic agent though a side
port adaptor and then through the through the introducer catheter
before it reaches the target tissue in the body as seen in FIG. 1,
although many variations are described herein where different
components and configurations are different to achieve a similar
result of driving the embolic agent to the target tissue. In some
examples described later herein, and as shown in FIG. 1, the
embolic delivery system includes a system of pulleys and a toothed
belt, whereby the drive system, in this case the hand of the
operator, turns a hand crank to drive the large pulley, which in
turn drives the feeder rollers, which then move the embolic agent.
The embolic delivery systems are all novel elements of this
invention, and include many variations that include different
sub-elements and mechanisms. Also described herein are embolic
delivery systems that utilize hydraulic propulsion mechanisms to
drive embolic agents. Also described is system using a combination
of feeder rollers and hydraulic mechanisms. Also described herein
are embolic delivery systems that include traction elements and a
to-and-fro motion of the driving mechanism, sometimes in
combination with a clamp, to drive the embolic agent to its target
tissue in the body. The pusher element can be an adjunct to the
embolic delivery system, and as such can serve to function as an
embolic delivery system or in conjunction with an embolic delivery
system. Also described are systems that provide for rapid
sequential delivery of a plurality of short or medium length
embolic agents.
[0050] The pusher element exists in simple forms conventionally in
the art, but is described in this invention in novel forms. They
are generally a long and narrow, and flexible enough to pass
through a catheter with curves, but rigid enough to push an embolic
agent through the catheter, such as the introducer catheter. Such
characteristics may be aided by transitions in stiffness along
their length. There are many possible variations of pusher elements
90. They may be composed of different metals or plastics or other
compounds, with varying degrees of stiffness of the various parts.
Some have no transition 95 and are of similar composition
throughout entire length. Some are helically wound, some are
mono-filamentous or mandrel wire composition. This is
conventionally manipulated by the hands of the operator, and is
used to push an embolic agent through a catheter into the target
area in the body. Conventional pusher elements are either attached
to the embolic agent or not attached. Those that are not attached
may push the embolic agent when both are constrained within the
lumen of a catheter whose inner diameter is roughly similar to the
outer diameters of the embolic agent and pusher element, much like
a piston pushing another piston through a hollow cylinder. This
type may not retract the embolic agent as they are not connected.
Pusher elements that are attached to embolic agents are detachably
attached since the pusher elements are not left inside the body
after use. Before detachment, there two elements are connected and
the embolic agent may be pushed or retracted by manipulation of the
pusher element. In novel embodiments of this invention, it may be
detachably or non-detachably connected to the embolic delivery
system to affect the proper movement of the pusher element. The
pusher element can be an adjunct to the embolic delivery system,
and as such can serve to function as an embolic delivery system or
in conjunction with an embolic delivery system. The pusher element
may also contain traction elements in some novel forms of this
invention, which may enable novel functions such as application of
a to-and-fro motion of the pusher element resulting in a net
forward advancement of the embolic agent, or retraction of the
embolic agent effected by manipulation of the pusher element
without a rigid attachment between the two elements. Conventional
pusher elements may be the same composition and structure as a
guide wire, and in some instances they are interchangeable,
although in most instances they will have slightly different
characteristics to facilitate their goals
[0051] The embolic containment apparatus is a container for the
embolic agent to store it and prepare it for delivery into the
body. Its structure depends on the embodiment as described later,
and may even be optional in some embodiments. A simple embolic
containment apparatus could consist of a solid spool, such as is
commonly used to store wire or cable or string, in which case it
can be as simple as a cylindrical spool of many different types of
materials. A slightly more complex embodiment could include a rigid
tank-like container which contains the spool and the filament, as
seen in FIG. 1, and allows dispensing of the filament out through
an opening to the embolic delivery system. This tank could be
fluid-tight and contain a solution to bathe the filament, or it
could be air filled and not be water tight. Such an embodiment as
depicted in FIG. 1 would be a novel aspect of this invention. Other
more complex structures such as a Side Port Adaptor may be
detachably or permanently connected to the embolic containment
apparatus to allow injection or aspiration of contents. A simple
embodiment could include a conventional bag, such as a plastic bag,
which contains a coiled or otherwise compacted embolic agent.
More complex and novel embodiments will be described later herein,
and can include an integration of the elements of the embolic
containment apparatus with the embolic delivery system. For
example, a rigid container, similar to a tank, can contain embolic
agent in such a manner as to permit hydraulic pressure to force the
embolic agent out of the containment apparatus and into the
introducer catheter or other component that will lead to the goal
of ultimate delivery of embolic agent to the target tissue in the
body. Another embodiment also involves an integration of the
embolic containment apparatus with the embolic delivery system, and
utilizes a solid plunger or piston to force the embolic agent out
of the embolic containment apparatus for purposes described above.
In some embodiments, the embolic delivery systems and the embolic
containment apparatus are integrated in such a manner that the
mechanical driver, for example the feeder rollers of the embolic
delivery systems, are housed within the embolic containment
apparatus, where they may be sealed within the fluid-tight system.
Many other variations and combinations of these novel elements are
possible. In some embodiments the embolic containment apparatus is
fluid-tight, but in others it is not. It is usually rigid in most
embodiments, but could also be flexible in some embodiments where
rigidity is not necessary. The embolic containment apparatus and
its variations are novel aspects of this invention.
[0052] A side port adaptor is a conventional device used commonly
in the art. It is usually rigid and composed of plastic or metal,
has one or more lumens, or channels that extends from one end along
its longitudinal axis, to the other end, permitting flow of a fluid
through them. It often has connector hubs on both ends that may
detachably or non-detachably connect to another device such as an
introducer catheter and/or an embolic delivery system or embolic
containment apparatus. Such connections are usually fluid-tight.
The side port adaptor also includes a side port that also contains
one or more lumens that permit a 3-way communication of the lumens
with the other ports.
[0053] A stop cock is a conventional device commonly used in the
art, which is composed of a rigid material, usually plastic or
metal, that has one or more lumens, 2 or more ports that
communicate via the lumen, and a handle or switch mechanism that
permits flow or restriction of flow through the lumens. Thus flow
of fluid into or out of any port is controllable by the operator by
manipulating the switch. The ports may be connected to other
devices such as introducer catheter or embolic delivery system to
permit or restrict flow of fluids or embolic agent between them.
The stopcock is usually fluid-tight, not permitting leakage of
contents to the environment, when the ports are attached to other
components, or when the switch mechanism is configured to restrict
flow.
[0054] The embolic detachment tools function to detach or fragment
the embolic agent to separate the portion intended to be delivered
to the target tissue inside the body from the portion to remain
unused outside of the body. There are many variations of possible
embolic detachment tools some of which are simple, conventional
devices such as a common pair of scissors seen in FIG. 1, or a
knife blade, whereas others are novel devices specific to this
invention. Some examples score the embolic agent, or alter it in
ways that permit its fragmentation and deployment as described in
more detail elsewhere herein. More complex embolic detachment tools
may include hydraulic means as described elsewhere herein, melting
devices, hot wires or burners, spark generators, sanders, shapers,
wire strippers, dissolution chamber (where a solvent is used to
dissolve an element), swaging tools, adhesives, embolic agent
modification tools, electricity sources such as a battery, and heat
chambers that provide heat within a specific range. In some
variations, the embolic detachment tool is attached to another
component such as the introducer catheter, so that it can detach
the embolic agent in a location remote from the operator, and/or
outside of the body. For example it could be integrated with the
distal end or tip of the introducer catheter. The embolic
detachment tool may also include a method for detachment that is
mostly accomplished by the Operator using his hands, such as
weakening techniques that utilize manipulations such as bending or
twisting that may be followed by rapid pulling or kinking to enable
detachment.
[0055] Traction Elements provide traction or friction to various
elements of the invention to enable an engagement of the members
such that motion of one member, possibly effected by the operator
or embolic delivery system will subsequently effect a desired
motion, in a desired direction, of another member. An example is
the presence of traction elements on an embolic agent such as a
filament, which engage the traction elements on another member,
such as a pusher element, so that manipulation of the pusher
element by the operator will direct the embolic agent through an
introducer catheter into the target tissues in the body. Traction
elements have many different possible shapes and compositions
including those described in more detail elsewhere herein for
embolic agents. They are rigid or semi-rigid. Some function by
using friction combined with mechanical elements creating a
slidable engagement between the two members allowing them to move
in relation to each other when desired, whereas others create a
stronger mechanical engagement where relational motion between the
two engaged members is very restricted, so that they move in
unison, until they are disengaged. Traction elements form
attachments that vary from easily detachable to substantially
non-detachable. Some traction elements or their manner of use are
novel aspects of this invention.
[0056] Guide wires are conventional elements, shaped as a long,
narrow, semi-rigid elements that fit within the lumens of
catheters, introducer catheters, introducer sheaths, or other
elements. It may be used to help guide the other element to its
target, or stabilize it, or hold an established path for passage of
an element later. Ideally, the guide wire is stiff enough to
perform the above functions, yet flexible enough to move forward
around curves, and to prevent damage to tissues in the body.
[0057] Guide wires are usually composed of metals such as stainless
steel, nickel-titanium alloys, platinum, or gold, among others, and
often have a coating of other substances such as a hydrophilic
polymer or other non-metallic compound to provide the desired
coefficient of friction and reduction of tendency to induce blood
clots when in contact with blood within the patient body.
[0058] There are many possible variations of guide wires. They may
be composed of different metals or plastics or other compounds,
with varying degrees of stiffness of the various parts. Some have
no transition and are of similar composition throughout entire
length. Some are braided, some are mono-filamentous or mandrel
composition. The guide wire may be the same composition and
structure as a pusher element, and in some instances they are
interchangeable, although in most instances they will have slightly
different characteristics to facilitate their goals. Many types of
guide wire and pusher elements are commonly used in the art. In
this invention, guide wires may have many different functions. It
can be advanced through the lumen of catheter into the desired
location inside the body, and then facilitate the passage of the
catheter to its desired location, and then withdrawn to permit the
use of the lumen for passage of fluids or embolic agent or other
materials. It may be used to maintain a pathway that has been
achieved through many elements such as stop cock, introducer
catheter, side port adaptor, embolic delivery system, and others,
so that a catheter or other agent may be passed over it co-axially
(guide wire inside lumen of agent), to its desired location. After
passing through these elements, it may then pass into the body, and
therefore maintain a path through the elements outside the body to
the target area inside the body.
[0059] An endograft is a conventional element, typically composed
of one or more tubes composing wide-caliber lumens that permit the
flow of blood, with a wall that prevents blood from passing
anywhere except the lumens. It may be a simple tube with one lumen
and 2 open ends that permit flow of blood in one end and out the
other, or it may be more complex, such as the commonly used shape
of a Y, or upside-down Y, where two tubes join to one tube, and
their lumens join, so that blood may flow into or out of 3 separate
lumen openings at the ends, as seen in FIG. 1. The endograft is
often composed of a metal skeleton for support, which results in a
flexible structure than could stand on its own, but may pass around
corners and bends in the body. Integrated with the metal skeleton
is usually a fabric wall made of woven polyester or expanded
polytetrafluoroethylene. The endograft is usually inserted into the
patient's body through a catheter that is inserted into an artery,
in a compacted form that reduces its diameter considerably to
permit passage through a much smaller hole than its ultimate fully
expanded diameter will become after deployment. Once deployed, it
is allowed to open to its full diameter, and attach to the inside
of the vessel by various means such as hooks or friction. It will
then permit flow of blood through its lumens, but not through its
wall, thus preventing flow into abnormal structures such as an
aneurysm in the patient's body as seen in FIG. 1.
[0060] Detachment mechanisms provide a detachable attachment
between an embolic agent and a pusher element or something that
functions as a pusher element, possible with other elements in a
line, said pusher remaining partially within the operating field
where the operator may manipulate it, providing control of the
embolic agent indirectly, which may be deep within the body beyond
the reach of the operator during crucial procedural steps.
Electrolytic detachment of embolic agents is a principle and
technique used in conventional embolic systems whereby electrical
current is passed through components and ionic fluid medium or
blood in a manner that takes advantage of well described
electrolytic effect of corrosion of a metallic component of the
circuit. The corrosion leads to disintegration of a segment of the
wire-shaped structure, which then results in disconnection,
fragmentation, or detachment, of the two newly separated
components. The configuration of polarity will determine the type
of electrochemical reaction that occurs and the desired effects of
corrosion of the detachment element. The choice of metals
determines the results as well. Stainless steel is a common metal
in medical products which is susceptible to rapid electrolytic
corrosion and is utilized in this invention. Nickel Titanium alloys
are used as well. "Non-corrodible" metals are referred to in this
document for simplification, but may actually be minimally or
slowly corrodible to degrees that are not significant when used in
the manners described herein. A common example of this is platinum,
which is commonly used in medical devices due to this effect as
well as its malleability, flexibility, and X-ray density. Some
embodiments of the embolic agent in this invention utilize
electrolysis to enable precise positioning of the distal portion of
the embolic agent within the body, to enable the operator to choose
the total length of the embolic agent, and to facilitate the
pushing of the embolic agent to the desired endpoint by allowing it
to remain continuous until in final position, and then fragmented,
and then proximal portion removed. Most of the electrolytic systems
described herein are novel due to inventions required to enable the
desired functions which were not conventionally available.
Mechanical detachment systems described herein achieve similar
results as described above but use mechanical means to provide the
detachable attachments necessary. Many mechanical systems have been
previously described, and herein we disclose new novel systems as
well as novel adaptations of existing detachment components to
achieve the novel functions we describe.
[0061] The operator is the specialist trained in the art who
performs the procedure using the elements of this invention for its
purpose. Most of the relevant manipulations and device controls are
performed by the hands of the operator as seen in FIG. 1. The
operator's hands are generally outside of the patient, since this
invention is predominantly used with techniques that permit passage
of materials into the body through small bore elements such as
introducer catheter and introducer sheath, although it may also be
amenable to open techniques, whereby the operator will perform a
larger surgical incision and use her hands and/or other instruments
to deploy the embolic agent using some or all of the elements of
this invention, in which case the operator's hands and/or some of
the elements of this invention will be inside of the body. In any
case these devices must enable delicate control of the elements
deep within the body that are outside of the direct reach of the
operator, through the other elements that extend into the
operator's field.
[0062] Turning now to the drawings, in which similar reference
characters denote similar elements throughout the several views,
the figures illustrate the main elements of this invention. Many
elements of the invention are seen in FIG. 1A and include an
introducer sheath 240, an introducer catheter 200, an embolic agent
1, an embolic delivery system 324, an embolic containment apparatus
500, a stopcock 560, a side port adaptor 530, an embolic detachment
tool 160, an operator 600, a body containing an abnormal cavity or
aneurysm 582, and an endograft 570. The embolic agent 1 is spooled
in the embolic containment apparatus 500, and fed by the embolic
delivery system 324, which is controlled by the operator 600, into
the side port adaptor 530 which has a stopcock 560 on its side
port, then into the introducer catheter 200, which passes into the
body 580 through an introducer sheath 240 that traverses the skin
and enters the femoral artery 585. The introducer catheter 200
passes up the arteries into the abnormal aneurysm 582, which
involves the aorta 586 in this example. The embolic agent 1 passes
through and beyond the introducer catheter 200 to fill the cavity
581 (aka sac) of the aneurysm 582. Embolic detachment tool 160 was
used to modify the embolic agent 1 prior to completion. FIG. 1B
contains main element guide wire 550 which is shown being used to
help pass the introducer catheter 200 into the aneurysm 582 prior
to introducing the embolic agent. FIG. 1C shows a pusher element 90
being used to advance the final portion of the embolic agent 1 into
the aneurysm 582. A linking element 110 and a detachment element
120 are seen in line between the pusher element 90 and the embolic
agent 1, enabling advancement and retraction of the embolic agent 1
until the operator 600 is satisfied with the position, when
detachment is initiated in the detachment element 120, and then the
embolic agent 1 and, in some embodiments, a portion of the
detachment element 120 is left in the aneurysm 582 and all other
components are pulled out. Traction elements are too small to
visualize in these overview drawings and are used in some
embodiments where they are described.
[0063] FIGS. 1D-L are longitudinal section schematic views teaching
some important concepts contrasting the prior art with some of the
novel aspects of this invention especially in reference to the
embolic agents. The embolic agents 1 and pusher elements 90 are
much longer than easily represented so smooth wavy lines are used
to represent continuity of the elements. Jagged lines indicate
detachment points 132. FIG. 1D represents a common conventional
embolic agent 1 and pusher element 90 commonly referred to as a
"pushable" embolic, usually a helically coiled wire. When both
elements are in the introducer catheter (not shown) which passes
from the extra-corporeal field to the intra-corporeal tissues the
operator may push the embolic agent deep into the body by pushing
the pusher element 90, but they may not retract it once pushed
(indicated by the one-way arrow pointing up). If the embolic agent
1 goes to a non-desired location in the body, it must remain there
because it cannot be pulled out or repositioned. The length ("Le")
of the embolic agent 1 is pre-determined by the manufacturer, and
is limited by practical necessity to be relatively short, generally
not longer than approximately 30 cm. as explained in more detail in
FIG. 1M-N. This may lead to use of a great number of embolic agents
at great cost and is technically impractical for large aneurysms.
Sometimes embolic agents 1 of this type are pushed hydraulically
instead of with a pusher element 90, e.g. by a syringe 653 which is
a commonly used simple device for creating hydraulic pressure. FIG.
1E is a two part sequence depicting a conventional system that
gives the operator the freedom to advance or retract the embolic
agent 1 by manipulating the pusher 90 (indicated by bidirectional
arrow) because they are securely attached together by a detachment
element 120 as on the left. When the embolic 1 is in the desired
position, detachment may be initiated at the detachment point 132
as seen on the right, relinquishing control over the embolic agent
1. Finally the pusher 90 is removed. This imposes two important
limitations of conventional agents. The length ("Le") of the
embolic agent 1 must be pre-determined by the manufacturer, and is
limited by practical necessity to be relatively short, generally
not longer than approximately 30 cm. as explained in more detail in
FIGS. 1M-N. FIG. 1F is a 3 part sequential schematic that
represents another conventional embolic device which involves
operator modification during the procedure. On the left, an embolic
agent 1 with a detachment element 120 and a pusher element 90 with
a mating detachment element 120 are available to the operator. In
the middle, the operator has modified the device in the operating
field by attaching the detachment elements 120 to each other, and
now has bidirectional control over the embolic agent 1 indirectly
by controlling the pusher element 90. In the final drawing, the
embolic agent has been pushed into the body, and the operator
detaches the components at the detachment point 132 between the
detachment elements 120. Note that the detachment point 132 is also
the location of operator modification, i.e. the joining of the
separate elements. The detachment elements are schematically
depicted as a screw-type system to broadly represent any type of
reversible mechanical attachment mechanism described. This
configuration is also subject to the limitations described in FIG.
1E and FIGs. M-N.
[0064] FIG. 1G depicts and demonstrates principles of variable,
operator-determined length (Le) of embolic agent 1 and the
practical capacity for lengths that are vastly greater than
conventional embolic agents, possibly over a hundred meters in some
embodiments, in addition to full operator control over advancement
and retraction of embolic agent 1. Such long lengths would not be
possible with conventional agents because the operator cannot
possibly predetermine the exact length that would be needed in such
a large cavity, so would have to use many conventional agents until
the endpoint was achieved. As shown in FIG. 1G, embolic agent 1
includes a series of repeating segments 52, each of which includes
a detachment element 120. The embolic agent 1 is pushed into the
body without a separate pusher element as the operator may push
directly on the embolic agent until the desired amount is in the
body cavity, at which point detachment is initiated at a selected
detachment point 132. In some embodiments, the detachment point 132
will be limited to that most proximate to the operator's field of
manual manipulation extra-corporeally, whereas in other embodiments
the detachment element 120 adjacent to, and distal to, said
proximate detachment element 120 may also be used for detachment,
and in other embodiments any detachment point 132 may be chosen for
detachment, although usually requiring modification of the desired
detachment element 120 by the operator prior to passage of said
modified detachment element 120 to the place of detachment if deep
within the body.
[0065] FIG. 1H is a sequential view depicting embolic agent 1 that
also has operator-determined length (Le) of embolic agent 1, and
the practical capacity for lengths that are vastly greater than
conventional agents, in addition to full operator control over
advancement and retraction of embolic agent 1. In addition, embolic
agents 1 in this category have infinite choices of detachment
points 28 without discrete detachment elements 120 (not shown) in
the manufacture-provided embolic agent 1. This is made possible in
part by embolic agents 1 that are modifiable extra-corporeally by
the operator in the manual operating field. In the second drawing,
after modification which is schematically shown as four vertical
lines at detachment point 28, the embolic agent 1 remains intact
and the operator retains control over advancement or retraction of
the embolic agent 1 by manipulating its trailing portion
extra-corporeally. When the desired position of the modified
embolic agent 1 is achieved, detachment may be initiated as seen in
the third drawing at detachment point 28.
[0066] FIG. 1I is a sequential view introducing the novel concept
of operator-controlled linking elements 110 in the extracorporeal
operating field to provide the functions of operator-determined
length (Le) of embolic agent 1, and practical capacity for lengths
that are vastly greater than conventional embolic agents, in
addition to full operator control over advancement and retraction
of embolic agent 1, and the presence of infinite choices of
detachment points 132 without the need for discrete detachment
elements 110 in the manufacture-provided embolic agent 1, with
potential manufacturing simplification. Once the desired length of
embolic agent 1 is determined by the operator, possibly after much
of it is already deployed within the body, it may be severed using
tools, with severed end schematically represented as jagged edge.
On the left, the severed embolic agent 1 is not yet linked to the
detachment element 120 which is already securely attached to the
pusher element 90 by manufacturer. In the center drawing, the
operator has used the linking element 110 to link the detachment
element 110 to the embolic agent 1. The operator now has control
over the embolic agent 1 outside or inside the body by manipulating
the extracorporeal aspect of pusher element 90. When desired
position of embolic agent 1 is achieved, detachment at detachment
point 132 is initiated as described previously. Because only one
detachment element 120 is needed, and because it does not need to
be manufactured into the embolic agent 1, this category permits the
use of a very wide variety of detachment element types, including
conventional types that have been modified in novel ways to suit
function in this novel manner, thereby greatly expanding their
utility beyond conventional systems. Nearly any described
detachment mechanism which has been thus far restrained to usage in
the limited manners of FIG. 1D-F may become the basis for novel
modifications that permit the greatly expanded utility of the novel
devices in the category described in FIG. 1I.
[0067] FIG. 1J is a three part sequential view of a category of
embolic agents 1 and related elements that permit roughly the same
functionality as described for FIG. 1I, however in FIG. 1J the
linking element 110 is manufactured as a separate piece, which is
used by the operator to link two other separate pieces including
the severed embolic agent 1, and the pusher element 90 with
attached detachment element 120. Once linked, the functionality is
similar to FIG. 1I. The separate linking element 110 seen in FIG.
1J provides some different functionalities that are explained in
more detail for each embodiment herein. FIG. 1K is a three part
sequential view of a category of embolic agents 1 and related
elements that permit roughly the same functionality as described
for FIG. 1I and FIG. 1J. It resembles conventional configuration in
FIG. 1F except that in FIG. 1K there is a linking element 110 which
is non-detachably attached to a detachment element 120 by the
manufacturer seen on the left. Once linked to the severed embolic
agent 1 by the operator, the functionality is similar to the novel
devices in FIG. 1I or FIG. 1J, with variable, operator-determined
length and full control of embolic agent 1 through manipulation of
pusher element 90 in the middle drawing, which is detached at will
as shown on the right. The detachment elements are schematically
depicted as a screw-type system to broadly represent any type of
reversible mechanical attachment mechanism described FIG. 1L is a 3
part sequential view of another category of this invention where on
the left is an embolic agent 1 that has been severed to desired
length by the operator, and a detachment element 120 non-detachably
attached to a pusher element 90. The severed end of the embolic
agent 1, with or without further modifications, is detachably
attached by the operator to the detachment element 120 without the
need of a linking element, as shown in the center, giving operator
control of embolic agent 1 via pusher element 90. On the right,
when desired, the detachment element 120 and embolic agent 1 are
separated at the same place as initial attachment not substantially
altered relative to before they were attached together.
[0068] FIGS. 1M-N schematically demonstrate important limitations
of conventional embolic devices and their solution by this
invention, and demonstrate why conventional embolic agents may not
be provided in very long lengths which are possible in this
invention. In FIG. 1M, a scenario is depicted which would very
frequently arise if a conventional detachable embolic agent 1 of
the type described in FIG. 1E or FIG. 1F were hypothetically
manufactured in very long lengths as is possible for our invention.
The detachment point 132 is near the end of the assembly of embolic
agent 1 and pusher element 90. The embolic agent 1 has been
partially deployed into the aneurysm 582 within the body 580, but
the endpoint of maximal embolization has been achieved before the
detachment point 132 has reached the aneurysm 582. No viable
options are now available. The remainder of embolic agent 1 cannot
be passed into the aneurysm 582, it cannot be severed or left
dangling partially out of the aneurysm 582 or the body 580, and it
would be dangerous to remove the great length of already deployed
embolic agent 1, as well as rendering the procedure useless. FIG.
1N is a two part sequence that shows how this invention addresses
this type of scenario due its length being variable and
operator-determined. The operator may decide, based on the progress
of the procedure in real time, where to position the detachment
point 132 along the great length of the embolic agent 1, or in some
embodiments, to choose from among many possible detachment points
132 along the entire embolic agent 1. In this example the operator
chose to enable a detachment point 132 at the position shown. The
detachment point 132 of the embolic agent 1 is passed into the
aneurysm 5982, where detachment will occur, followed by the removal
of un-needed portions from the body.
[0069] FIGS. 2A-6Y depict different inventive embodiments of the
embolic agent 1 as described herein. The depicted embolic agents 1
are stiff enough to push through the lumen of a catheter, but
flexible enough to fold or kink or bend in order to compact into
the cavity of the target tissue such an aneurysm. They have a
proximal end 18 which is the last to enter the body, or to be
detached from the remainder and discarded. There is also a distal
end 19 which is the first to enter the body, and middle 20 in
between. Their main function is to occupy the cavity to promote a
desired biologic effect such as blood clotting, or tissue healing
or scarring to permanently fill the space that was once occupied by
gas or fluid with clot, or other solid body tissue. The embolic
agents 1 may be pushed to their target directly by the hands of the
operator outside of the proximal end of the introducer catheter, or
by the embolic delivery system, or may be pushed by a pusher
element which is in turn pushed by the hands or an embolic delivery
system.
[0070] An embolic agent 1 may be composed of any biocompatible
substance that is capable of becoming filamentous in structure.
Possibilities include, but are not limited to:
[0071] Polytetrafluoroethylene (PTFE)
[0072] Expanded Polytetrafluoroethylene (ePTFE)
[0073] Polyester (PET)
[0074] Polypropylene (PP)
[0075] Polyamind (Nylon)
[0076] A fluoropolymer
[0077] A polyurethane
[0078] Biocompatible Thermoplastic
[0079] Metallic wire or thread, such as platinum, stainless steel,
gold, nickel-titanium alloy (e.g. "Nitinol"), alloy mixture, or any
metal or combination of metal that provides the column strength
necessary to be pushed through the catheter. It may have an
attached agent such as woven polyester fibers, or any other fiber
or fabric that can be attached to the wire to provide extra bulk
and thrombogenicity (help clot the blood). It could be structured
as a helical wire or coil, such as the conventional construction of
common 0.035 inch diameter angiographic guide wires widely
available. This may contain a solid mandrel wire for extra
stiffness, or may occur without the mandrel, thus providing a very
soft and flexible, bendable, and nestable wire. An example of such
a wire could be a wire similar to the common Bentsen 0.035 inch
guide wire with its mandrel removed.
[0080] The embolic agent 1 could be constructed from a
biodegradable substance such as a polyglycolide, a poly L-lactide,
a poly DL-lactide, a poly-caprolactone, a copolymer, or others.
Embolic agent 1 may comprise monofilament or multifilament in
structure, e.g., braided, woven, or yarn. Its diameter would permit
it to fit through a hypo-tube or catheter capable of being inserted
into an artery or cavity, usually, but not exclusively, a diameter
in the range of 0.008'' to 0.1.''
[0081] Important properties of the embolic agent 1 include the
coefficient of friction when dry and in aqueous environment,
flexibility, pushability, elastic modulus, stiffness, diameter,
tensile strength, and surface irregularity, as relates to friction
as well as area of thrombogenic surface exposed to the blood. Also
important in some instances is shape memory. The embolic agent 1
may be straight in its resting state, or it may be coiled or have
any type of complexity of multiple curves to form a complicated
nest or compact structure. It may be introduced in a straightened
form as it is constrained it its packaging or the catheters, and
then assume its resting shape when placed in the target area. It
may also exhibit thermal memory, meaning that it takes on different
shapes when at different temperatures. This could allow it to be
introduced in a relatively straight form, and then more readily
compact into a multiple curved configuration at body temperature
once deployed at target.
[0082] The embolic agent 1 will need to be stiff enough to allow
pushing into and through the catheter without buckling outside of
the proximal end of the catheter. Once inside the catheter, the
embolic agent 1 will occupy most of the lumen diameter, and will
therefore be much less prone to buckling. However it must have
enough flexibility to permit nesting and folding into the aneurysm
sac with extensive redundancy, so that a great length of it can be
deployed and provide replacement of a substantial volume of the
aneurysm, thus providing vast total surface area to promote
thrombosis of blood. A braided material may provide an even greater
surface area on a microscopic level. A hydrophilic compound may be
used to keep the wet friction very low.
[0083] The embolic agent 1 may be rendered visible on X-ray imaging
using techniques that are commonly used in the art. If the embolic
agent 1 is metallic, it may be adequately radio-opaque. If it is
not, a metallic wire core or stripe may be applied or contained
within the embolic agent 1 to provide opacity, or opaque markers,
such as dense metals such as gold or platinum, may be placed along
the embolic agent 1, either on its surface or imbedded within. The
embolic agent 1 may be diffusely or discontinuously impregnated
with a radio-opaque substance mixed into its composition or applied
like a film, or layered within, to provide visibility under X-ray.
Such substances may include barium or bismuth. The various shapes
of embolic agent 1 are further described below. To enhance the
hydraulic and/or mechanical propulsion of the embolic agent 1, the
shape can be altered in numerous ways, some of which are depicted
herein.
[0084] FIG. 2A is a perspective view and FIG. 2B is a longitudinal
section view and FIG. 2B-1 is a cross-section view that depicts a
simple shape of embolic agent 1. The embolic agent 1 is a simple
elongated cylindrical shape, round in cross section, with a
proximal end 18, middle portion 20, and distal end 19. Non-depicted
variations could include rounded ends. In the depicted embodiment,
it is a solid and flexible monofilament 5, with enough column
strength to allow pushing through a catheter, but enough
flexibility to bend or coil and fit into spaces much smaller than
its full length. It may be composed of any of the substances listed
herein including polymers or metal, or other biocompatible
substances which provide the above characteristics as described
herein. The surface of the embolic agent 1 is substantially smooth
to reduce friction resistance as it is delivered to the aneurysm or
cavity site. FIG. 2C depicts an embolic agent 1 similar to FIG. 2A
except its surface is much rougher, imparting different properties
which may be desirable for handling during the procedure or for
biologic effects once implanted. FIG. 2D shows an embolic agent 1
which is composed of many strands 4 grouped together much as a
string or rope may be made from many finer strands 4. Here, the
strands 4 are composed of even smaller strands which are too small
to be visible in the figure, and are grouped into the larger
strands 4 that are depicted. Various contemplated embodiments would
include different types of grouping configurations including simple
bundling, weaving, braiding, yarn configuration, or any other type
of pattern that may yield a filamentous embolic agent 1. This
embolic agent 1 may have different surface, biological,
thrombogenic and physical properties than the simpler
mono-structure depicted in FIGS. 2A-B.
[0085] FIG. 2E is a longitudinal section view and FIG. 2E-1 is a
cross-section view that shows an embodiment of embolic agent 1 with
shapes and composition similar to FIG. 2A, however with the
addition of nodes 8 that are roughly spherical, and have a greater
diameter than the rest of the embolic agent 1, which is elsewhere
constant in diameter with a circular cross section as shown. The
nodes 8 can appear at any interval along the length of embolic
agent 1 and in one example will occur every X length, where X is
shorter than the length of the introducer catheter. Node 8 may act
as a piston in a cylinder (for example, the inside lumen of the
catheter) where it fits snugly so as to allow hydraulic propulsion
of the embolic agent 1, while allowing fluid to flow around the
smaller diameter embolic agent 1 to reach the bead. Node 8 could be
manufactured from any of the materials described in this invention
including polymer, plastic, hydrophilic material, metal, or any
other rigid or semi-rigid compound. It may contain dense material,
such as platinum or gold, to provide opacity under X-ray. In
another contemplated embodiment, the node 8 may not encase the
proximal end 18 of the monofilament 5 or its variant material, and
instead it may be welded or adherent to the tip of the end of the
monofilament 5 or variant material. The nodes 8 are concentrically
located along the embolic agent 1, whereas in the embodiment
depicted in frontal view in FIG. 2F and in cross section in FIG.
2F-1, the nodes 8 are eccentrically located along the embolic agent
1 in a variation, but with similar function. Nodes 8 depicted are
roughly spherical, but variations may be cylindrical, globular, or
slightly amorphous, so long as it's greatest diameter is similar to
the lumen of the introducer catheter, and still have the desired
hydraulic effect, functioning similarly to a piston that results in
a substantial seal with the walls of the introducer catheter while
still allowing motion through the catheter when hydraulic pressure,
or pusher wire, is applied behind it.
[0086] FIG. 2G depicts an embodiment of an embolic agent 1 that is
suitable for hydraulic injection. It consists of a monofilament 5,
which is round in cross section, has a proximal end 18, and a
distal end 19. Attached to the proximal end 18 is a node 8, which
consists of PTFE in this example. Node 8 is roughly spherical, and
in this example surrounds the proximal end 18 of the monofilament
5. Node 8 is the same, or very slightly smaller, diameter as the
introducer catheter 200 (not shown) to be used with it, so that the
node 8 will function as a piston that is easily moved by a
hydraulic force behind it, as well as by a pusher element such as a
wire (not shown) as described elsewhere in this invention. The
point of contact between node 8 with the wall of the catheter will
be very short, keeping the friction between them to a minimum. The
monofilament 5 is narrower in diameter than node 8, and hence also
narrower than the catheter lumen, so it will also slide easily
through the catheter when hydraulic force is applied to the node.
In one embodiment instead of a monofilament 5, any other type of
long and narrow material for embolic agent 1 described in this
invention, including braided filament, wire (mandrel, braided, or
wound), with or without fiber attachments may be utilized. FIG. 2H
is a frontal view of a variation of FIG. 2G where the node 8 is
attached to a helical wire 33 similar to that described elsewhere
in this invention. In other respects, FIG. 2H is similar to FIG.
2G. FIG. 2I is a longitudinal section view and FIG. 2I-1 and FIG.
2I-2 are cross-section views that depict another embodiment of
embolic agent 1. Embolic agent 1 is also circular in cross-section
but has variable diameters throughout its length as shown. The
narrower segments will be referred to as notches 9, between
repeating segments 52 of main body 40. In this embodiment, the
notches 9 are simply variations in the diameter of the embolic
agent 1 and are concentric. This serves a similar function as the
nodes described herein. In this embodiment, the larger caliber of
the embolic agent 1 may fit snugly into the lumen 209 of the
introducer catheter 200 (as shown in the different figures herein),
to allow hydraulic propulsion of the embolic agent 1 as fluid
pressure is transmitted at the smaller caliber portions of the
notches 9. The notches 9 may also serve to make the embolic agent 1
more flexible and compactable. The length and diameter of the
variable segments 52 and notches 9 could include many variations.
This shape might offer advantages in manufacture, especially if it
could be formed from the stretching and/or biaxial orientation of
segments 52 of an embolic agent 1 to produce the narrower segments
52. FIG. 2J depicts another embodiment of embolic agent 1 which is
circular in cross section in its repeating segments 52 of main body
40 between notches 9, where the notches 9 are eccentrically
positioned.
[0087] FIG. 2K includes two perspective views of an embolic agent 1
with different types of notches 9 than shown above. The top view is
a surface view and the bottom view shows the same embolic agent 1,
depicting the internal configuration with dashed lines. In this
embodiment, embolic agent 1 is a monofilament 5, round in
cross-section as seen in FIG. 2K-1, with many notches 9, one of
which is depicted, between repeating segments 52 of monofilament 5.
These notches 9 form a circumferential hood-like protuberance which
can be used for hydraulic effect, acting like pistons within the
lumen of the introducer catheter, to help move the embolic agent 1
through the catheter upon injection of fluid, with the direction of
motion as shown by dotted arrow. This embolic agent 1 may be
manufactured by cutting a circumferential notch into the filament
by applying the cutting device along the longitudinal axis of the
embolic agent 1, thus splitting away the hooded portion from the
underlying portion of the notch 9. A variation could be made by
applying a hooded portion to a filament without cutting into it.
FIG. 2L is a longitudinal surface view and FIG. 2L-1 is a cross
section view depicting a similar embolic agent 1 with
non-circumferential notches 9 that are cut into the embolic agent
1, perhaps by a blade, between repeating segments 52 of main body
40. These non-circumferential notches 9 would not act as sealed
pistons, since the cross-sectional shape is not a circle, however
they will create drag that could help propel the embolic agent 1
hydraulically within the catheter lumen when fluid is flowing
through it. Various contemplated embodiments of embolic agent 1 may
include different compositions of material and different
configurations of notch 9.
[0088] FIGS. 2M-N depict two different embodiments of conventional
embolic agents 1 composed of helically wound metal wire 33. FIG. 2M
includes a surface view and a cut-away view showing the helically
wound wire 33 to be round in cross section, and with hollow space
inside 34. In this example, the wire 33 is comprised of wire loops
that are not welded or joined together in any way, imparting a
great deal of lateral flexibility if desired. The degrees of
flexibility, column strength, tensile strength tendency to unravel,
and electrolytic properties may be adjusted by use of various
metals as known in the art, diameter of the wire 33 that is wound
into the helical shape, and the diameter of the overall helical
shape. In variation, welds or bonds between some of the loops of
wire 33 may be created to change its physical properties, generally
imparting more stiffness, column strength, and tensile strength. It
may optionally have a mono-filament smaller wire or non-metallic
fiber running through its core, tethered at the ends or other
various points by welds (not shown) to change the properties to
provide more stiffness, or to prevent unraveling or stretching. The
embolic agent 1 is depicted as straight, however it may have memory
shape to assume other configurations as described below. Helical
wire embolic agents are conventionally available, however are
limited in length to always be shorter than the introducer
catheters, usually substantially shorter, in order to be manually
pushed with a simple pusher element similar to a conventional guide
wire as explained in FIG. 1M-N. In this novel invention, the
helical wire embolic agent 1 may be vastly longer, many times
longer than the introducer catheter, because its precise
flexibility and handling characteristics, combined with the novel
embolic delivery systems and novel detachment systems described
herein permit feeding of the novel very long embolic agents
described herein. FIG. 2N includes two surface views depicting a
conventional embolic agent 1 containing a helically wound wire 33,
seen in restrained and unrestrained shapes. It has fiber
attachments 3 at various intervals, composed of tufts of very fine
strands of woven polyester or other similar fine flexible filament.
The top view depicts it straightened, as when constrained within a
catheter (not shown). The bottom view shows it unconstrained, as
when implanted in a cavity. Embolic agent 1 has shape memory, and
when unconstrained, it will assume its pre-determined shape such as
the helix depicted, although it could assume any of many shapes,
including linear, or simply conforming to the space it occupies,
since it is flexible. The fiber attachments 3 serve to occupy space
within the target tissue or aneurysm, and promote blood clotting or
favorable tissue reaction. Many variations are possible which
utilize different shapes or different compositions to similar
effect. Any embolic agent described in this invention disclosure
may similarly have a memory shape other than the depicted shapes
that are used to illustrate the important characteristics of each
embolic agent. Variations could include many different types of
composition of the embolic agent 1 or its fiber attachments 3, and
many different sizes and configurations.
[0089] FIG. 2O is a schematic diagram of several varieties of three
dimensional memory shapes of embolic agent 1 when unconstrained
within a hypo-tube or catheter. From left to right, the shapes
depicted comprise a simple spiral, multiple loops,
three-dimensional cage, chaotic nest, and random curves. These
shapes may apply to many compositions and sizes of embolic agent 1.
It is contemplated that a vast variety of different shapes and
configurations of embolic agent 1 are possible and in keeping with
this invention.
[0090] FIGS. 2P-S are frontal views that depict various embodiments
of embolic agent 1. These are departures from the long filamentous
shapes described thus far. These are shorter in length, usually
only a few centimeters, and therefore will require serial
administration in greater quantities to fill abnormal cavities.
FIG. 2P depicts an embolic agent 1 with a cylindrical shape, solid,
having a proximal end 18, a middle 20, and a distal end 19. This is
flexible or semi-rigid, and may pass through the lumen of an
introducer catheter as described herein. It may be pushed to the
target tissues using mechanical means or hydraulic means described
herein. In this depiction, embolic agent 1 comprises a polymer
monofilament, however in many variations it can be composed of any
material listed elsewhere herein. As with all embolic agents
described in this invention, variations could also include rounded
ends, notches, nodes, hollow lumen, threads, locking mechanism,
fiber attachments, memory shape, or a longitudinal slit, as
depicted and described in detail elsewhere herein. FIG. 2Q, depicts
an agent 1 similar to that in FIG. 2P, but even shorter in length,
such that its length is actually less than its diameter. It is
otherwise similar in composition and function to that in FIG. 2P.
FIG. 2R depicts a spherical embolic agent 1 that is otherwise
similar in composition and function to that in FIGS. 2P-2Q. FIG. 2S
is a sequence view that depicts an embolic agent 1 with fiber
attachments 3 of polyester or similar fine biocompatible thread,
attached to a solid rigid core 12, intended for use through
relatively large diameter introducer catheters 200 as
conventionally available in the field. When unconstrained, this
embolic agent 1 has roughly the shape of a sphere. When constrained
inside the lumen 209 of the introducer catheter 200, it may
elongate slightly, as it compacts overall in size. Once it is
pushed out of the introducer catheter 200 into the target tissues,
it will expand due to the natural tendency of the tuft of curly
fiber attachments 3 to expand. This embolic agent 1 may be pushed
by mechanical or hydraulic forces described herein. In variation,
the core may be more cylindrical, or it may be absent, and instead
the tuft of woven fibers may have integrity of its own, much like a
conventional cotton ball.
[0091] FIG. 3A shows another embolic agent 1 in longitudinal and
cross section view 3A-1. The embolic agent 1 is little different
from the embolic agent shown in FIG. 2O, except that the ends are
rounded. Three individual embolic agents 1 are shown end-to-end as
could occur during use inside an introducer catheter 200 (not
shown) or other system element. The embolic agent 1 has a proximal
end 18, a middle 20, and a distal end 19. It is round at all levels
in cross-section FIG. 3A-1. The proximal end 18 is seen abutted
against the distal end 19 of the identical embolic agent 1 below
it, and likewise for the third agent on the bottom. It can be seen
that pushing on the bottom embolic agent 1 would result in forward
motion of the other two if all were contained inside the lumen of
an introducer catheter as described herein. It is also evident that
pulling backward, or retracting, the bottom embolic agent 1 would
not necessarily pull the other two embolic agents, since they are
not attached or connected together. This represents a simple system
for administering many relatively short embolic agents 1 into the
target tissues through an introducer catheter by loading them into
the introducer catheter 200 and pushing them forward using
hydraulic or mechanical means as described herein.
[0092] FIG. 3B shows a similar embolic agent 1; however the shape
is slightly more complex. It is also round in cross-section as seen
in FIGS. 3B-1 and 3B-2 at all levels, but there are different
diameters at different levels. The proximal end 18 and distal end
19 are larger in diameter than the middle section 20, and are equal
in diameter to each other. In variation, the transition between
different diameters may be more gradual.
[0093] FIGS. 3C-D, 3C-1 and 3D-1 are longitudinal and cross
sectional sequential views of more complex embodiments of the
embolic agent 1 of FIG. 3B where interlocking elements are included
to provide additional stability during deployment. Although the
specific shapes of the elements in FIGS. 3C-3D are different, the
major characteristics are similar and will be described together
here for both figures. The embolic agent 1 has a male locking
element 24 on its distal end 19, and a corresponding female locking
element 25 on its proximal end 18. The middle section 20 is solid,
and most of the embolic agent 1 is solid, depicted as the solid
portion 23, except for the proximal end 18 containing the female
locking element 25, which is basically a hollow portion 22 that is
surrounded by the solid portion that is round in cross section on
its inner and outer surfaces. The inside and outside surfaces of
the entire embolic agent 1 at any level are round. On the left
view, two such embolic agents 1 are shown separately, and will come
together as shown by dashed line where the male locking element 24
is mated with the female locking element 25, comprising the locking
mechanism 10. The locking mechanism 10 will typically be intended
to fit snugly, but not tightly, so that pulling the proximal
embolic agent 1 downward will not necessarily pull the distal
embolic agent with it. Likewise, advancement of the distal embolic
agent 1 will not necessarily advance the lower one, which could be
left behind. The locking mechanism 10 may facilitate the passage of
a series of multiple embolic agents 1, which can be very numerous
in number, in a smooth manner, through various elements of the
system including the introducer catheter (not shown), embolic
delivery system (not shown), their connections, and any others.
They will tend to stay lined up as desired when passing through
areas where they are not circumferentially constrained. At any
time, they may be easily disengaged by being pulled apart.
[0094] FIGS. 3E-I depict embodiments of embolic agent 1 which is
hollow, and therefore has a tube-like general configuration. As
with other embolic agents described herein, this embolic agent 1
has a configuration and composition that permits its introduction
into target tissues using embolic delivery systems 324 described
herein. Instead of a solid core, it includes a hollow lumen 7. Its
composition could be of any of the substances described elsewhere
herein for embolic agents. Similar hollow tubes exist in the art
for purposes such as micro-catheters that are designed to allow
delivery of fluids or small particles to target tissues. In this
invention, the tube is adapted in novel ways to serve as an embolic
agent 1. FIG. 3E is a perspective view depicting a simple example
of a hollow embolic agent 1. It is round in cross-section, has a
hollow lumen 7, and a thin wall 2. It has a proximal end 18, middle
20 section, and a distal end 19. As described for other embolic
agents herein, the distal end 19 is passed into the target tissues
first. The purposes of this embolic agent 1 are the same as
described elsewhere herein, but its function may be different. The
thin wall 2 and hollow lumen 7, combined with the use of a flexible
substance of composition, will enable this agent to fold and kink
and nest very well inside the target tissue, as seen in FIG. 3H
where a small segment of a hollow embolic agent 1 is easily kinked
and folded by minimal external forces. Such kinking could occur at
innumerable points along the length of the embolic agent 1. Another
quality of the hollow embolic agent 1 is that it will occupy a
greater volume of space using less material compared to an
otherwise similar solid filament or wire. Its lumen 7 will have
potential for flow of fluid, or creation of hydraulic pressure, or
be capable of permitting insertion of a guide wire, as described
here and in the detailed description of the embolic delivery
system. It may also permit novel detachment or fragmentation
mechanisms as described elsewhere herein, notably in the detailed
description of detachment mechanisms. As will be described in more
detail in the description of traction elements 270 hereafter,
traction elements 270 may be applied inside or outside of the
hollow embolic agent 1 with structure and function described
therein.
[0095] FIG. 3F depicts is an upper perspective exploded view
showing a hollow embolic agent 1, containing a lumen 7, a wall 2, a
proximal end 18, a middle section 20, and a distal end 19 similar
to seen in FIG. 3E. However, there is the addition of baffles 11,
which are fluid-tight plates or membranes that seal off parts of
the lumen 7 from other parts. The baffles 11 connect to the wall 2
circumferentially with a fluid-tight seal. A baffle 11 is shown on
the distal end 19, which is shown in FIG. 3G, where it provides a
seal of the distal end 19. Referring back to FIG. 3F, fluid flowing
into the lumen 7 on an end of the embolic agent 1 would meet an
obstruction upon reaching a baffle 11, and could lead to an
increase in hydraulic pressure or propulsion of embolic agent 1
forward, depending on whether it was allowed to move by external
forces. Variations of the hollow embolic agents 1 could include
various compositions, wall thickness, lumen sizes, and lengths. The
baffles could have different configurations and still be in keeping
with their intended function in this invention of creating
fluid-tight seals in the lumen 7. The baffles 11 could be of any
number and spacing along the embolic agent 1. In other variations,
the baffles could be non-fluid tight. Instead, they might contain
holes or porosity or configurations that provide partial
obstruction to flow of fluids, but not complete obstruction. In
this manner drag could be produced without complete blockage of
flow. The hollow embolic agent 1 may be open on both ends, closed
on both ends, or open and closed on alternate ends. When closed on
both ends, it may have porous seals or fluid-tight seals, which
would or would not permit inflow of fluid into the lumen 7,
respectively. The hollow embolic agent 1 may be radio-opaque, or
radio lucent, or may utilize markers as described for other embolic
agents herein.
[0096] FIG. 3I depicts a hollow embolic agent 1 containing a wall 2
and lumen 7 with a baffle 11 closing the distal end 19. It would
have a different propulsion characteristic inside an introducer
catheter compared to a solid embolic agent 1 or a hollow embolic
agent 1 with a baffle 11 on its proximal end 18. The hydraulic
pressure would be directed more towards the distal end 19, thus the
embolic agent 1 could be less prone to buckling inside the
introducer catheter 200 or embolic delivery system 324. In effect,
it would behave somewhat as if it was pulled through the introducer
catheter than as if it was pushed from its proximal end 18. Much
like a windsock, it would be kept fully expanded during this phase
of deployment. Once in position in the target tissues, the loss of
internal pressure could result in easy kinking and folding as
desired.
[0097] FIG. 3J introduces two more contemplated embodiments that
may be used alone or in combination with other embolic agents 1 as
depicted elsewhere herein. The embolic agent 1 example in this
figure is hollow having a lumen 7 and a wall 2, round in cross
section, semi-rigid, and composed of polymer. It also has ridges 15
along its outer wall. These ridges may be cut or formed into the
wall 2 of the embolic agent 1, having many different possible
shapes depending on ease of manufacture, but here depicted as small
triangular protuberances that are circumferential around the
embolic agent 1. These provide extra traction with an embolic
delivery system 324, as in this example where feeder rollers 325
are being used to drive the embolic agent 1. The feeder rollers 325
also have small corresponding ridges which will be called roller
grooves 326, to provide extra traction, although in variation the
roller grooves 326 may be absent. In other contemplated
embodiments, any other type of embolic delivery system 324
described in this invention herein may be used alternatively, and
the ridges 15 may still serve to provide extra traction or
desirable handling characteristics when manipulated by the
operator's hands. Other variations also include elements other than
ridges as depicted to provide this extra traction. All of the
surface characteristics depicted elsewhere herein in the detailed
description of traction elements 270 could alternatively be used.
Another embodiment is the ridges 15 may not be circumferential
around embolic agent 1. Ease of manufacture might lead to use of
scoring or ridges that extend only partially around the
circumference of the embolic agent 1, or that extend
circumferentially with interruptions. Also shown in FIG. 3J is a
longitudinal slit 17 along the long axis of the embolic agent 1.
This is a cut through the entire wall 2 thickness on one side (not
involving the diametrically opposite wall), which permits the
semi-rigid embolic agent 1 to be opened up along the longitudinal
slit 17 to expose the inner lumen 7, which is now not a continuous
circle. In this figure, the longitudinal slit 17 does not extend
entire length of the embolic agent 1, but is incomplete at its
distal end 19. In different embodiments, it may involve the entire
length or a lesser length than shown. The longitudinal slit 17
permits opening of the embolic agent 1, which may then be fed onto
a guide wire or other similar object using methods as described in
the more detailed descriptions of embolic delivery systems
herein.
[0098] FIGS. 4A-C depict various embodiments of embolic agent 1
with screw-like threads 16 to facilitate delivery. FIG. 4A is a
surface view of a solid embolic agent 1 which is composed of metal
or non-metallic materials described herein and has threads 16
circumferentially around its surface much like the threads of a
screw in appearance and function. Embolic agent 1 is circular in
cross-section as seen in FIG. 4A-1. It is flexible as a result of
its flexible composition, or if metallic, due to its very small
diameter, similar to a wire strand. This embolic agent 1 may be
driven by a rotating threaded driver which functions like a nut on
a screw, which when rotated and not allowed to move longitudinally,
will drive the embolic agent 1 forward or backward, depending on
direction of rotation of driver. Alternatively, threads 16 may
engage the ridges 15 or threads 16 on feeder rollers 325 as seen in
FIG. 3J. The embolic agent 1 may have a shape memory as described
elsewhere herein, although shown here in its straight form as it
would be when constrained. FIG. 4B shows a similar threaded embolic
agent 1 as seen in FIG. 4A, with the addition of notches 9 at
intervals along its length. It is solid and circular in cross
section as seen in FIG. 4B-1. Notches 9 may facilitate folding or
kinking of the embolic agent 1 once deposited in the target
tissues, and are more likely to be added for embolic agents 1 with
relatively larger diameters in their main segments 38. FIG. 4C
shows another variation where the embolic agent 1 is not solid. As
seen in FIG. 4C-1, but is instead small wire that is wound in a
manner to create an outer surface similar to the threads 16 of
FIGS. 4A-B. This may provide much flexibility while still
permitting the mechanical functions of the threads. Optionally,
there may be several weld points 21 along its length (see FIG. 4C)
where adjacent coils of the wire are welded together. These change
the characteristics of the embolic agent 1 by reducing its lateral
flexibility, and decreasing its tendency to unravel when the ends
are pulled in opposite directions. The frequency of weld points 21
serves to adjust the flexibility to desired characteristics. In
other variation, longitudinal stretch resistance is instead
provided by a small straight wire or fiber thread in the core that
is tethered at both proximal and distal ends of the embolic agent
1, as seen in FIG. 9D.
[0099] FIGS. 5A-F are surface and cross-sectional depictions of
flexible, predominantly non-metallic embolic agents 1 with
radio-opaque markers 13 (FIGS. 5A-E) or radio-opaque substance 14
(FIG. 5F) that will improve visualization during fluoroscopic
guidance and diagnostic imaging. Markers 13 made of dense
radio-opaque metal, such as platinum, gold, tantalum, bismuth,
barium, stainless steel, nickel-titanium alloy, or others are
integrated with the embolic agent 1, and as shown in FIG. 5F,
radio-opaque substance 14 is diffusely impregnated in the embolic
agent 1 during manufacture as is sometimes utilized with
angiographic or venous access catheters in common practice. Also,
elements with functions related to electrolytic detachment, or
fragmentation of the embolic agent 1 into at least 2 fragments
through use of electrolytic corrosion, are outlined in some of the
figures. The elements coating 31 and capsule 43 are discussed, both
describing an electrically insulating layer of non-metallic
material surrounding a substantial portion of an electrolytically
corrodible wire to provide electrical insulation and prevent
corrosion of the wire portion that it covers. In general, the term
coating 31 is used for a thin layer, and capsule 43 for a bulkier
layer, however these distinctions are relative and their
characteristics can be so similar in some embodiments that they may
be nearly interchangeable in meaning. The need to distinguish them
arises mostly when both layers are present in the same embolic
agent 1, where the capsule 43 is usually surrounding the coating
31.
[0100] In FIG. 5A, a long metallic wire 6 is surrounded mostly,
except on its proximal end 18, by a capsule 43, which is flexible,
non-metallic, solid, and may be substantially dielectric. The wire
6 may be electrolytically corrodible in variations where this
function is desired. It may also serve as a marker 13. In this
figure, it is centrally located in the core of the embolic agent 1
as seen in FIG. 5A-1. Other variations could include a plurality of
wires 6, or different lengths or extent on the embolic agent 1, or
located elsewhere than centrally, either within the perimeter of
the cross section of the embolic agent 1, or on its outside
surface. A method of manufacture could include co-extrusion of
marker(s) 13 with embolic agent 1. In addition to serving as a
marker 13 or instead of serving as a marker 13, the wire 6 may be
used to impart the desired balance of flexibility and columnar
strength. The wire 6 may also be used to facilitate electrolytic
detachment as described herein using novel tools and methods to
expose a portion or portions of the wire 6 to make them susceptible
to electrolytic corrosion. In various embodiments, the wire 6 in
the proximal end 18 of the embolic agent 1 may be surrounded by the
capsule 43 as is the rest of the wire 6. In FIG. 5B, the wire 6 or
wire marker 13 is eccentric (i.e. it extends most or all of the
body 40 of the embolic agent 1), however is not located at the
center on the cross-section views of FIGS. 5B-1 and 5B-2. Two types
of embolic agents 1 are depicted which have two different methods
of manufacture. FIG. 5B-1 shows a monofilament containing the wire
6 or wire marker 13, such as might occur if the monofilament were
extruded over the wire as a capsule 43. FIG. 5B-2 shows the wire
marker 13 or wire 6 is sandwiched between a core 12 and an outer
layer 32 of the capsule 43, such as might occur with a co-extrusion
of the 2 layers with the wire 6 in between. As in FIG. 5A, this
wire 6 may also be used to provide the desired physical and/or
electrolytic properties described herein. The wire 6 is completely
encapsulated in this depiction, but in variation various areas may
be exposed as described herein.
[0101] In FIG. 5C, the markers 13 are small spherical shaped beads
spaced apart at various intervals along the body 40 of the embolic
agent 1 which is a non-metallic monofilament 5. FIG. 5C-1 shows
that markers 13 are centrally located in the cross-section of
embolic agent 1, however in various embodiments they may be
positioned at various locations within or on the surface of embolic
agent 1. In FIGS. 5D and 5D-1, markers 13 are bands around the
perimeter of the embolic agent 1, which are swaged onto the body 40
keeping the outer diameter substantially identical to non-banded
portions of the embolic agent 1. Alternatively, these band markers
13 could be sandwiched between layers 32 of the embolic agent 1
(not shown). In FIG. 5E, an embolic agent 1 that is hollow (as in
FIG. 3E), with markers 13 which may be in the lumen 7 held in place
with adhesive or by deformation of the inner wall 2 as in FIG. 5E-1
or with markers 13 located eccentrically in the wall 2 as in FIG.
5E-2 where it is imbedded in the substance of the wall 2 using
manufacturing methods described herein or conventionally available.
FIG. 5E-3 depicts a portion devoid of markers 13. Other embodiments
could include various shapes and sizes of marker 13. In FIG. 5F and
FIG. 5F-1, there is diffuse impregnation of a radio-opaque
substance 14 within the composition of the body 40 of the embolic
agent 1. FIG. 5G is a frontal view and FIG. 5G-1 is a magnified
cross section view of a hollow embolic agent 1 with a lumen 7 and a
wall 2, and two different types of markers 13. The upper marker 13
is swaged onto the body 40 over a mandrel (inside the lumen to
prevent collapse) similarly to FIG. 5D, and the lower marker 13 is
sandwiched between layers 32 in the wall 2. This embolic agent 1
also has a fine, loosely wound helical wire 33 within its wall 2 to
prevent crushing of the embolic agent 1 upon handling or feeding
into a catheter, while still allowing flexibility and folding or
buckling. FIG. 5H is a perspective view and FIG. 5H-1 is a
magnified cross section view of a hollow, tubular-shaped embolic
agent 1 with a wall 2 and a lumen 7. There is a metallic wire 6,
which may be electrolytically corrodible, running throughout most
or all of the body 40 within the wall 2, which is encapsulated and
not exposed to the environment or lumen 7, similar to other
variations shown or described in FIGS. 5A-B, 5J-M, 6A, 6C-E, and
6G-K, but not limited to these variations. In the embodiment of any
encapsulated wire variations just named or described elsewhere
herein, encapsulation may be incomplete as exposed wire may be
present to allow application of electrical current as described
herein. Wire 6 may also serve as a marker 13. It may provide the
desired physical characteristics and/or electrolytic effects
described herein. Embolic agent 1 may also utilize a coiled wire,
or other wire configuration separate from wire 6, within its wall 2
for radial support, as described in FIG. 5G.
[0102] FIG. 5I is a frontal view and FIG. 5I-1 is a magnified cross
sectional view of an embolic agent 1 composed of non-metallic
flexible capsule 43, which may be dielectric, substantially
encapsulating several wires 6 running longitudinally, oriented
end-to-end, differing from FIG. 5A in that the wires are not one
continuous wire, but are separated by gaps 41. This may serve
purposes of creating the desired physical characteristics such as
more flexibility in the gaps 41, possibly also aided by the
placement of notches 9 as in FIG. 2I, as well as electrolytic
properties serving to direct corrosion and detachment to a location
proximal to a gap. Electrical current will not pass from one wire 6
segment to the others even if within ionic solution, so if
electrolytic detachment is performed in the manner described
herein, it will only occur along the wire 6 segment that is
included in the circuit, which may occur at any location where the
manufacturer or the operator exposes the wire 6 to the electrolytic
environment such as blood or ionic fluids. The segments of wire 6
distal to the gap will not be electrified, hastening the speed of
electrolytic corrosion to the desired point of exposure. The
distance between gaps 41 in the wire 6 will usually be greater than
the length of the introducer catheter (not shown) so that
detachment can occur at or beyond the catheter tip while current is
applied to the proximal embolic agent 1 outside the body of the
patient in the manner described herein, to a portion where the wire
6 is exposed. This use of gaps 41 in the wire 6 may be applied to
other variations containing a long wire insulated by a non-metallic
coating or capsule, for example in FIGS. 5A-B and 5G-H.
[0103] FIG. 5J is a frontal view and FIG. 5J-1 is a magnified cross
section depicting an embolic agent 1 which includes an encapsulated
wire 33 where wire 33 is helically wound within the capsule 43. As
in other variations depicted herein, the body 40 is substantially
dielectric and hence insulates the wire. As in other examples
described herein, the metallic wire 33 may also serve as a marker
13. The use of the helically wound wire 33 may serve to provide the
desired physical handling characteristics, as well as possibly
serve for electrolytic detachment as described herein. FIGS. 5K-M
are each frontal views and FIGS. 5K-1-5M-1 are cross section views
depicting solid embolic agents 1 that contain a wire 6 or helical
wire 33 encapsulated in the body 40 of capsule 43 which is
non-metallic and substantially dielectric. FIG. 5K and cross
sections FIGS. 5K-1 and 5K-2 depict notches 9 in the body 40. FIG.
5L and cross sections FIGS. 5L-1 and 5L-2 depict notches 9 which
are undulating and smooth as shown. FIG. 5M and cross section FIG.
5M-1 depict an encapsulated helical wire 33, which differs from
FIG. 5J in that the diameter of the helical wire 33 is closer to
the diameter of the capsule 43, imparting different handling
characteristics. In each of these depictions, the wire 33 may also
serve as a marker 13. Various contemplated embodiments may include
combinations of the features described herein including notches 9
for FIG. 5M, gaps 41 in the wires, or other variations as described
herein.
[0104] FIGS. 6A-6F are longitudinal frontal views and FIGS.
6A-1-FIG. 6B-1 are cross-section views for FIGS. 6A-B, of different
embolic agents 1 that are made of flexible, electrically corrodible
wire 6 (e.g. stainless steel) or helically wound wire 33, with a
thin coating 31 of substantially dielectric flexible material (e.g.
PTFE) or another polymer of necessary thickness and lack of small
holes that provides substantial low-voltage electrical insulation.
Coating 31 may not provide substantial bulk to the overall volume
of the embolic agent 1, but it may affect the handling
characteristics of the wire such as lateral flexibility, and may
also serve to provide lubricity or reduced coefficient of friction
as may be desired for the invention. The coating 33 and its use
with regard to electrolytic corrosion and detachment are very
different from conventional surface coatings of helical wires which
are intended mainly to alter handling characteristics and not for
electrical insulation. The presence of very small holes, thin
areas, and flaky disruption did not completely prevent electrolytic
corrosion at undesired locations as demonstrated in our tests,
resulting in slower corrosion at desired locations and undesired
physical changes in the deployed embolic agent 1. In FIGS. 6A-F, as
in other embodiments of electrolytic embolic agents in this
invention, the entire portion of wire composed of corrodible metal
that may be in the proximity of the ionic medium promoting
electrolytic corrosion is coated and therefore resistant to
corrosion except in any described areas where coating is removed or
intentionally not applied in order to serve as a contact for
electrification or as a site for intentional corrosion and
detachment. FIG. 6A and cross section FIG. 6A-1 depicts an
embodiment with complete or nearly complete coating 31 over the
entire body 40 of the wire 6. Exposed wire 6 without coating 31 may
be present on the proximal end (not shown) to provide contact with
electrical source as described herein. Electrolytic corrosion and
detachment could only occur where a second portion of coating is
removed by operator to expose the wire 6 as described herein. FIGS.
6B and 6B-1 is a variation of FIG. 6A which includes two or more
bare portions 39 of wire 6 that are not covered by coating 31, and
are thereby available for electrical conductivity with another wire
or electrolytic fluid as described herein. The bare portions 39 may
also serve as detachment points 28 where electrolytic corrosion of
the wire 6 may occur, permitting separation of the embolic agent 1
into two fragments at that location as described herein. The bare
portions 39 may occur at various locations along the body 40 of the
wire 6, including areas that have been deposited within the
aneurysm or cavity. FIG. 6C-F relate to variations that include
helically wound wire 33 with different configurations of coatings
31, each of which may have different ease of manufacture, and
different physical properties such as column strength and lateral
flexibility. However, all serve to provide an electrical insulation
from an ionic environment in which they might be positioned, such
as during deployment in the tissues, whereby points of contact and
detachment may be controlled by the placement of bare areas 39
where desired. In FIG. 6C, the insulating coating 31 is applied to
the helical wire 33 after it has been wound, with application of a
continuous layer to the internal surface 54 facing the space inside
34, and to the external surface 42. This may decrease flexibility
of the embolic agent 1 due to a binding effect of the wire coils to
each other, and for this reason a very pliable and stretchable
coating 31 material might be most suitable. In FIG. 6D, the coating
31 surrounds the entire surface of the wire 33 strand that was
wound into the helix. One method of manufacture could involve
coating the wire 33 strand prior to winding the helix, while
another method could involve winding, followed by partial
stretching to slightly separate loops, followed by coating,
followed by resumption of more compact depicted configuration by
memory effect of the wire or by reshaping methods. This helical
wire 33 may retain a great flexibility since the individual coils
are not bound together, permitting use of a coating 31 with minimal
pliability as could be advantageous for other reasons of
manufacture or biocompatibility. In FIG. 6E, the coating 31
surrounds the external surface 42 and distal end 19 of the helical
wire 31 but not the internal surface 54 facing the void 34 inside.
This may be relatively simple to manufacture, however may have
similar implications for lateral flexibility as described for FIG.
6C and may benefit from a pliable and stretchable coating 31
material. FIG. 6F depicts a variation of helical wire 33 with
coating 31 most notable for its presence of non-coated bare
portions 39, which may serve as detachment points 28, at various
possible locations along the body 40 of the helical wire 33,
similar to that depicted for the non-helical wire in FIG. 6B. These
bare areas may be placed by the manufacturer or the operator using
tools as described herein, and may occur in all embodiments of
helical wires 33 in FIGS. 6C-F. Various embodiments may include all
coating 31 types depicted in FIGS. 6C-E. FIG. 6F also depicts the
presence of radio-opaque markers 13, showing how they may be
positioned internally within the void 34 in the interior of helical
wire 33, as may occur with any type of helical wire in this
invention. In a common embodiment the markers 13 would be slightly
proximal to the bare portions 39 so that the proximal end of the
embolic agent 1 is easily identified after detachment occurs at the
detachment point 28. As in other helical embolic agents in this
invention, those in FIGS. 6C-6F may contain a longitudinal straight
wire or fiber which is tethered at the ends or two or more other
points along the embolic agent 1 within its core to impart handling
characteristics or resist stretching or unraveling.
[0105] FIGS. 6G-I are frontal views and FIGS. 6G-1, 6H-1, and 6I-2
are cross section views of embolic agents 1 with complex coatings
and encapsulations which may be used for electrolytic detachment as
described in the simpler embodiments above. In FIG. 6G, an
electrolytically corrodible wire 6 has a thin coating 31 of
dielectric flexible material as described in FIG. 6A, and this
coated wire 6 is surrounded by a helical winding of a flexible,
non-metallic monofilament 5. This may provide desired bulk and
thrombogenicity and desired radio-density properties (such as to
prevent excessive accumulation of radio-dense metal in the aneurysm
or cavity by occupying space with non-radio-dense material). The
helical winding of the filament 5 may facilitate lateral
flexibility of the embolic agent 1 compared to a bulky solid
encapsulation. The inner coating 31 provides electrical insulation
even though the wound monofilament 5 may be porous to liquid and
therefore not completely insulating. The wound monofilament 5 may
be prevented from unraveling or separating from wire 6 by use of
adhesive or heat treatment to create enough bonding between the
coils, without inducing excessive overall stiffness of the embolic
agent 1. In variation, the mono-filament 5 could be substituted
with a single multi-stranded filament 4 that is braided, yarn,
bundled, or woven for slightly different handling properties. FIG.
6H also includes an electrolytically corrodible wire 6 with a thin
dielectric coating 31. However, it is surrounded by multiple small
diameter monofilaments 5 which are bundled and helically wound
around the wire 6. This may provide desired bulk, thrombogenicity,
radio-opacity characteristics, and flexibility, with preservation
of electrical insulation by the coating 31 where desired. In
variation, each monofilament 5 may be substituted with non-metallic
multi-stranded filament 4. The filaments in FIGS. 6G-H may be
amenable to heat melting such that a bare portion of the wire could
be created using a hot wire or readily available cautery pen or
other source of heat to cut and melt the strands without fraying at
the modified area.
[0106] FIGS. 6I, 6I-1, and 6I-2 depict an embolic agent 1 which
includes an electrolytically corrodible wire 6 with a dielectric
coating 31, which is mostly encapsulated in a capsule 43 of
relatively bulky, flexible, non-metallic solid material roughly
similar to FIGS. 5K-M, however different in that in FIG. 6I the
notches 9 in body 40 are deep enough to completely expose the
coating 31 on the wire 6. The notches 9 help to provide lateral
flexibility, as well as facilitating complete exposure of the wire
6 by the operator, by removing a short segment of coating 31 where
exposed in the notch 9 through means described herein, and
resulting in creation of a potential electrolytic detachment point
28 of the operator's choosing. In variation, the wire 6 may be
completely exposed in the notch 9, (i.e., the coating 31 may be
absent in a small bare area in the notch 9), preventing need for
the operator to remove the coating 31 in this location to expose
the wire 6, however potentially resulting in multiple sites of
potential electrolytic corrosion or detachment. Variations in FIGS.
6G-I may include use of helical wire instead of straight wire,
application of radio-opaque markers, exposure of the wire on the
proximal end of the embolic agent which will not be deployed within
the aneurysm or cavity, gaps in the wire, and other variations as
described herein.
[0107] FIG. 6J includes sequential views of a variation of embolic
agent 1 with encapsulation of an electrolytically corrodible wire
6, which also has easily removable seals 48 that provide electrical
insulation of the wire 6 while allowing the operator to expose the
wire 6 in the desired location(s) to permit electrolytic detachment
in keeping with the objectives of this invention. On the left is a
longitudinal section with cross section views depicted in FIGS.
6J-1, 6J-2, 6J-3 and 6J-4. Arrow indicates transformation by
operator to configuration on right, where a longitudinal section is
depicted and includes cross section views FIGS. 6J-5, 6J-6, 6J-7
and 6J-8. Referring to the figure on left, the embolic agent 1 has
a capsule 43 that surrounds a majority of the wire 6, providing
electrical insulation. It has no inner coating. There are gaps 41
in the capsule 43, which are a type of notch 9 where adjacent
segments of capsule 43 are completely separate from each other.
Easily removable seals 48 are dielectric, used to insulate the wire
6 at the gaps 41 by providing a fluid-tight seal with the adjacent
segments of capsule 43, effectively maintaining insulation of the
wire 6. The easily removable seals 48 are very flexible, allowing
bending of the embolic agent 1 at the notches 9 where the capsule
43 provides less restriction to motion than elsewhere in the body
40. The easily removable seals 48 may be easily removed by the
operator when desired, exposing the underlying wire 6 at the bare
portion 39, making it susceptible to electrolysis at the potential
electrolytic detachment point 28 Three different types of easily
removable seals 48 are depicted in this figure, although actual
device may only incorporate one type in one or more locations. The
gap 41 depicted on top is sealed with the easily removable seal 48
called tape 45. The tape 45 is a thin strip of flexible,
fluid-tight, non-metallic dielectric material with adhesive on one
surface that can be applied to the embolic agent 1 at manufacture
circumferentially around the gap 41, adhering tightly to the
adjacent segments of capsule 43 and providing a fluid-tight seal
under the conditions of use of the device. The operator may easily
peel off the tape 45, exposing the bare area 39 or the wire 6, and
establishing a potential electrolytic detachment point 28. The
middle gap 41 depicts an easily removable seal 48 provided by
sealant 46. Sealant 46 is a compound which may be applied at
manufacture in liquid or semi-solid form, and curing to a pliable,
flexible solid or semi-solid that surrounds the wire 6 and conforms
to the edges of the capsule 43. The operator may easily peel or rub
this sealant 46 off when desired. In variation, the sealant 46 may
be dissolved by a solvent that is applied to it. Choice of
compositions of sealant 46, solvent, and capsule 43 will
intentionally permit dissolution of sealant 46 but not of capsule
43 or wire 6, so that capsule 43 remains intact, but wire 6 bare
area 39 is exposed, creating potential electrolytic detachment
point 28. An example of a possible solvent is Dimethyl Sulfoxide
(DMSO). Other variant sealants 46 have a melting point higher than
the capsule 43 but much lower than wire 6. Application of heat
slightly greater than melting point of sealant 46 using tools
described herein will result in liquefaction of sealant 46,
exposing bare area 39. The bottom gap 41 depicts an easily
removable seal 48 comprised of a sealant plug 47, which is firm but
flexible, pliable, and solid or semi-solid. It is roughly shaped
like a disk but with upper and lower surfaces which mate with the
adjacent segments of capsule 43 to provide a seal, and closely
surrounds the wire 6, with intention to provide watertight
electrical insulation of the underlying wire 6. The sealant plug 47
also has a radial slit 44 as seen if FIG. 6J-4, which due to the
plug's 47 pliable nature, may be widened to permit application of
the plug 47 to the embolic agent 1 as shown on the left, as well as
easy removal by the operator, creating the bare area 39 and
potential electrolytic detachment point 28 as seen on the
right.
[0108] FIG. 6K includes sequential dimensional frontal views and
FIGS. 6K-1 and 6K-2 include cross section views teaching the
concept of electrolytic detachment in a very simple form. On the
left, the embolic agent 1 is shown intact, with an electrolytically
corrodible wire 6 encapsulated within a capsule 43, except for its
proximal end 18 where the wire 6 is exposed to serve as an
electrical contact 36. This exposure may be during manufacture, or
may be created by the operator using methods described herein, and
may involve proximal areas other than the most proximal end of the
embolic agent 1 depicted. After near complete advancement of the
embolic agent 1 into the target tissues 589, a small focal portion
of the capsule 43 is removed using a tool or any of the various
methods described herein, said removal occurring at the mid-portion
20 of the embolic agent 1 which is still outside the body in the
operating field, creating the depiction in the middle 20, where the
bare portion 39 of the wire 6 is now seen, constituting a potential
detachment point 28, as seen in the middle drawing. The embolic
agent 1 is advanced further through the introducer catheter (not
shown), placing the distal end 19 and bare portion 39 into or near
the target tissues 589 in the body where desired as seen in the
third drawing on the right. Electrical energy is applied. The
electrical source 176 outside of the body is connected to
electrical wires 220, one connected to the bare area 39 at the
proximal end 18 of the embolic agent 1 which is outside of the body
and not in electrical continuity or contact with the body or body
fluid in the target tissues 589, and the other in contact with the
body or more directly to the ionic body fluid, such as blood, in
the target tissues 589 bathing the mid portion 20 and distal
portion 19 of the embolic agent 1, including the bare portion 39 of
the wire 6 at the detachment point 28 as discussed elsewhere
herein. As shown, electrolytic corrosion occurs at the detachment
point 28, and the distal portion 19 of the embolic agent 1 is now
physically separated from the remainder, which may then be
withdrawn from the body from the operator, leaving only the distal
portion 19 within the body at the precise desired location. Many
different types of embolic agents and configurations, different
mechanisms of energy application, and other specific novel devices
to facilitate and improve this process are described in this
invention and this simple example serves to introduce the concept
in a simple form.
[0109] FIG. 6L is a schematic representation to teach a concept
that may be mentioned in this invention relating to distances
between potential detachment sites 28 of an embolic agent 1,
especially when such sites are placed by the manufacturer instead
of the operator. As shown, L is the length of the introducer
catheter 200 from proximal end 206 to distal end 210 which may be
any length but will generally be between 10 cm and 110 cm. In
general, the distance between potential detachment sites 28 of the
embolic agent 1 will be at least greater than L, so that when it is
passed through the introducer catheter 200, the distal detachment
site 28 may be beyond and outside the distal end 210 of the
introducer catheter 200 while the proximal detachment site 28 is
outside of the proximal end 206 of the introducer catheter 200
where it is accessible to the operator outside of the patient's
body. Although this description may help to understand a typical
embodiment of the invention disclosed herein, exceptions occur and
are described herein, and other variations may occur in keeping
with the spirit of the invention.
[0110] FIG. 6M is a frontal view of an embolic agent 1 composed of
a conductive corrodible helical wire 33 with a coating 31 over most
of its surface as described herein (FIGS. 6C-E) where at least one
potential detachment area 28 is produced at the time of manufacture
or by the operator by stretching or shaping the coiled wire 33 in a
controlled manner to straighten the wire while separating the
coiled segments from each other, and stripping the coating from the
small area, as shown. This straight segment has no coating 31,
resulting in a bare portion 39, and therefore susceptible to
electrolytic corrosion using principles and methods described in
this invention. In keeping with descriptions in this invention, the
bare portion(s) 39 may be created by the manufacturer or the
operator to direct detachment 28 of the embolic agent 1 as desired.
In variation, the helical wire 33 may have a short bare portion 39
without having a straight portion, (i.e., there may not necessarily
be any alteration of the helical wire's 33 shape associated with
the presence of the bare portion 39).
[0111] FIGS. 6N-O are longitudinal sections of two types of embolic
agents 1 using electrolytically corrodible connectors 35. FIG. 6N
includes two or more segments of electrically conductive,
non-electrolytically corrodible helically wound wire 33 (e.g.
platinum) with one or more potential detachment points 28 at the
site of several connectors 35. The connectors 35 are straight,
substantially cylindrical, pin-like sold metallic structures made
of conductive, electrolytically corrodible material which are
non-detachably attached to the internal surface of the helical wire
33, partially occupying the space inside 34, leaving a bare portion
39 between the segments 52 of helical wire 33. They are attached by
mechanical, frictional, welding, or chemical bond. Electrolytic
corrosion may be directed to the detachment points 28 because
electrical current may be conducted to them through the conductive,
non-electrolytically corrodible helical wire 33 segments from a
source remote from the detachment point 28. Notches 9 may be
optionally present, consisting of narrowing of the connectors 35 at
the intended detachment points 28, to facilitate and direct
corrosion of the thinner portions. The notches 9 may be from
machining, stretching, or pre-corrosion of the connectors 35 at
manufacture. FIG. 6O is similar to FIG. 6N but has further addition
of a non-conductive insulated coating 31 to the helical wire 33 in
possible manners shown in FIGS. 6C-E which does not cover the
detachment points 28 on the center of the connectors 35, thus
directing corrosion to detachment points 28. This may permit the
use electrolytically corrodible metals such as stainless steel for
the helical wire 33 since corrosion will not occur due to
insulation. The points of contact between connectors 35 and helical
wire 33 will however not be coated so that electricity may be
conducted along the embolic agent 1 from segment 52 to segment 52.
In variation of FIGS. 6N-O, variations of tape, sealants, or plugs
as described in FIG. 6J may be easily adapted for similar function,
to provide easily removable seals which could insulate the
connectors 35 from electrolytic corrosion until precise choice of
detachment point 28 is chosen by operator for detachment. As with
all embolic agents in this invention, radio-opaque markers 13 may
be added as described.
[0112] FIGS. 6P-T depict novel embolic agents 1 that permit
variable, operator-determined length of detached embolized
segment(s) 52 utilizing electrolytic detachment without the need
for modification of the embolic agent 1 by operator prior to
detachment. FIGS. 6P-T all depict embolic agents 1 that have a
repeating cycle of a segment 52 of non-conducting material such as
non-metallic monofilament 5 or coated wire, then an electrical
contact 36 which conducts electricity to a bare portion 39 of
corrodible connector 35 which is a potential detachment site 28, to
another segment 52 of non-conducting material such as monofilament
5, and then repeat. Such embolic agents 1 may function in
combination with introducer catheters that have electrical contacts
near their distal ends, to conduct electricity to the contacts 36
on the embolic agent 1, as described later in this invention, for
example in FIGS. 12F, 12G, 12H, and 14B. FIG. 6P is a frontal view
from a slightly elevated perspective and FIGS. 6P-1, 6P-2 and 6P-3
are three cross sectional views depicting an embolic agent 1 whose
main body 40 is composed mainly of a non-conductive material in the
shape of a monofilament 5 as described herein. Rigidly attached is
at least one area of a substantially noble or non electrolytically
corrodible conductive material such as platinum that provides an
electrical contact 36 that is roughly disc shaped and is seen in
FIG. 6P-1 to have a hollow center through which a metallic
corrodible and conductive connector 35 may pass and to which said
contact 36 is connected. During manufacture, this contact 36 may be
swaged onto the monofilament 5 and connector 35 simultaneously
while they are held end-to-end as shown, and/or could be attached
using adhesive, bonding the segments 52 of monofilament 5 into a
long embolic agent 1 with adequate tensile strength. The contact
may also serve as a marker 13 especially since minimally corrodible
metals such as platinum serve well as markers 13. The upper portion
of the connector 35 is shown non-detachably attached to the distal
end 19 of the next segment 52 using a different method; the
connector 35 is inserted into a hollowed space in the monofilament
5, and a marker 13 is swaged around the monofilament 5, providing a
strong connection between connector 35 and monofilament 5. Adhesive
could also be used. The segments 52 of monofilament 5 are therefore
connected into a continuous embolic agent 1 with adequate tensile
strength. These 2 methods of bonding the elements may be
interchangeable, using one or the other on both sides of the
connector 35, or substituting with other conventional method
providing the same function. There may be a plurality of segment 52
connections along the embolic agent 1. Such a novel configuration
provides for novel function, in that electrical current passing to
the contact 36 via a wire in the electrolytic introducer catheter
that contacts it (not shown) as will be described later, will then
conduct into the corrodible connector 35, and said connector 35 may
thus undergo electrolytic corrosion and detachment at detachment
point 28. The substantially non-corroding contact 36 serves to
provide constant contact with the mating contact of introducer
catheters during electrolysis when corrosion is occurring in the
corrodible segment 52 of the connector 35, and is likely to occur
at the indicated detachment point 28 instead of point of contact
with the contact 36 since it is not in contact with the ionic fluid
at the latter location. In this example, a second marker 13 is
present as a band around a narrowing of the monofilament 5 as is
often used conventionally. This second marker 13 may be useful for
determining that proper separation of the segments 52 has taken
place, and that the proximal end 18 has separated from the distal
end 19 so that the distal end 19 may serve as embolic agent 1 in
the tissues while the proximal end 18 may be removed from the body.
Other contemplated embodiments that could provide similar novel
function include the use of a multi-strand non-metallic filament
instead of the monofilament 5, presence of other markers or a wire
inside the filament to provide structural support, use of a
non-corrodible helical wire 33 or straight wire, or a coated
corrodible helical wire or coated straight wire instead of the
monofilament 5, so long as said wires were not in electrical
continuity with the connector(s) 35. In variation this detachment
mechanism does not need to be in series, and may only be present in
one location, providing novel detachment function in conjunction
with a conductive electrolytic catheter described in this
invention.
[0113] FIG. 6Q is a longitudinal section view and FIG. 6Q-1 is a
cross section view depicting an embolic agent 1 which may function
roughly similarly to the embodiment shown in FIG. 6P but whose
structure permits use of fewer sub-elements with possible
simplification of manufacture and decreased cost. It has segments
52 of non-metallic monofilament 5 separated by notches 9, said
segments 52 acting as insulating capsules 43 for segments of
electrolytically corrodible wire 6 which are separated by
dielectric gaps 41 to prevent continuous conduction of electricity
along the entire length of the embolic agent 1. In the notches 9,
the corrodible wire 6 is not coated or encapsulated as is a bare
portion 39 which may be a detachment point 28 with electrolysis.
Although the precise position of the wire 6 within the capsule 43
is not limiting and could vary in different embodiments, in the
notches 9 the wire 6 is positioned eccentrically as shown, in order
to touch the sides of an introducer catheter through which it will
be advanced. Said introducer catheter would have a contact point
within its distal lumen as seen in some varieties described herein,
which would come into electrical contact with the contact 36 of
embolic agent 1. When provided with the opposite polarity contact
within the surrounding tissues and fluids, corrosion at the
detachment point 28 will separate the desired segments 52 of
embolic agent 1. The operator may direct the detachment to the
specific desired site by aligning the desired contact 36 with the
contact on the introducer catheter. The dielectric gaps 41 between
segments 52 of wire 6 will prevent corrosion of any other of the
many possible bare portions 39 along the embolic agent 1.
[0114] FIG. 6R is a longitudinal section and FIG. 6R-1 is a cross
section view depicting another embolic agent 1 which may be used
similarly as described for FIG. 6Q but has different structure,
mainly due to the addition of a non-corrodible wire 49 to serve as
an electrical contact 36. In FIG. 6R, and as shown in FIG. 6Q, the
discontinuous corrodible wire 6 is contained in a capsule 43 except
the bare portions 39 which may serve as detachment points 28 in the
notches 9, and has dielectric gaps 41 between wire segments 52. In
FIG. 6R, the corrodible wire 6 does not serve as a contact 36, but
instead electricity is conducted to the corrodible wire 6 via a
contact 36 comprised of a non-corrodible wire 49 that extends both
inside and outside the capsule 43 as shown. Inside the capsule 43,
the non-corrodible wire 49 is in direct contact with the corrodible
wire 6. As with FIG. 6Q, the contact 36 may contact the contact
within the introducer catheter as described herein. FIGS. 6P-R have
different manufacturing implications but may provide roughly
similar functionality.
[0115] FIG. 6S is a longitudinal section and FIG. 6S-1 is a cross
section of an embolic agent 1 which will also have similar
functionality as described in FIGS. 6P-R, however depicts an
embodiment that utilizes a helical wire 33 throughout most of its
length instead of materials described for the other embodiments.
Embolic agent 1 has segments 52 of electrolytically corrodible
helical wire 33 which are protected from electrolytic corrosion by
a coating 31 as shown. In variation, non-electrolytically
corrodible helical wire could be used without a coating. A
connector 35 composed of an electrolytically corrodible metal is
non-detachably secured to adjacent segments 52 of helical wire 33
which are separated by a notch 9, connecting them with adequate
tensile strength for purposes described herein. Electrical contacts
36 composed of a non-corrodible conductive metal are swaged or
soldered or adhered non-detachably to the connector 35, providing a
means for electricity to be conducted from a contact in the
introducer catheter (not shown) to contact 36, then to the
connector 35 which has a bare portion 39 where corrosion may occur
and is therefore a detachment point 28. The contact 36 may also
serve as a marker 13. Non-conducting adhesive 50 binds and
insulates portions of the components helical wire 33, connector 35,
and contact 36 as shown, preventing conduction from the connector
35 or contact 36 to the helical wire 33 segments 52. Alternatively,
a non-conductive coating 31 may be applied to the portions the
connector 35 and contacts 36 that contact the helical wire 33. A
plurality of these connections, at many possible distances apart,
may be present. Current applied to a contact 36 will only energize
the corresponding connector 35 and no others since current cannot
pass through the coating 31 to the helical wire 33 and hence to
adjacent segments 52, so precise point of detachment 28 can be
directed by the operator by positioning relative to the introducer
catheter without previous modification of the embolic agent 1 as
described herein. In variation, one of the contacts 36 or markers
13 may be omitted and the remaining functions still provided.
[0116] FIG. 6T is a longitudinal section and FIG. 6T-1 is a cross
section of a variation of FIG. 6S where a different structure to
the connector 35, marker 13, bare portion 39, and detachment point
28 are present, although operator usage is roughly similar. The
corrodible helical wire 33 segments each contain a detachment point
28 where a bare portion 39 is present as shown, involving as few as
one coil or even a tiny portion of one coil, while the remainder of
the helical wire 33 segment is rendered non-corrodible by coating
31. Current from a contact in an electrolytically-adapted
introducer catheter is conducted to the helical wire 33 in the
lower segment 52 at the intrinsic electrical contacts 51 with the
connector 35 where it touches the internal surface 54 of the
helical wire 33 adjacent to the space inside 34, where there is no
coating. Only the external surface 42 is covered and insulated by
non-conductive adhesive 50. Therefore the only electrified bare
portion 39 of corrodible metal is at the detachment point 28 shown
so is the only area where corrosion will occur. The proximal
portion of the upper segment 52 of helical wire 33 has
circumferential coating 31 and will not be energized when the
electrical current is activated and directed by the operator to the
depicted contact 36. A plurality of these connections 35 will
permit choice of location for detachment without operator
modification of the embolic agent 1 by positioning of selected
contact 36 with the corresponding contact in the introducer
catheter.
[0117] FIGS. 6U-6Y-1 are longitudinal section and cross section
views depicting novel embolic agents 1 that permit variable,
operator-determined length of detached embolized segment(s) 52
utilizing electrolytic detachment 28 after extracorporeal
modification of the embolic agent 1 by operator to direct
detachment 28 to the desired site. The embolic agent 1 becomes one
electrode, and the opposite electrode is supplied by contact at the
skin or on a novel electrolytic catheter as part of this invention.
Operator modification of embolic agent 1 is not at detachment point
28 and remains extracorporeal for FIGS. 6U-W, and is at detachment
point 28 for FIGS. 6W-Y. FIGS. 6U, 6U-1 and 6U-2 depicts an embolic
agent 1 which includes a plurality of repeating segments 52, each
including a capsule 43 encapsulating the majority of a segment 52
of electrolytically corrodible wire 6, said wire 6 bridging
adjacent capsules 43, thereby serving as a connector 35, which has
at least one bare portion 39 or is entirely bare, thereby serving
as an electrolytic detachment point 28 in the notch 9 between
capsule segments 52. A dielectric gap 41 exists between adjacent
wires 6 to prevent conduction from one wire 6 to the next. To
detach the embolic agent 1 at the desired location, the operator
will first use a tool extra-corporeally as described herein to
remove a focal portion of capsule 43, at a location such as example
modification site 53, to expose the wire 6 creating an electrical
contact proximal to the intended detachment site 28, and then apply
current to the newly created bare portion (not shown) contact which
will energize the single desired intra-corporeal detachment site 28
without energizing potential detachment sites 28 more distally
since the dielectric gaps 41 exclude them from the electrolytic
circuit. The distance from extracorporeal modification site 53 to
nearest distal detachment site 28 will usually be greater than the
length of the introducer catheter with this variation. Possible
methods of manufacture could include extrusion of capsule 43 over
wire segments, or extrusion of capsule 43 over a long continuous
wire followed by laser disruption of wire through capsule 43 to
create dielectric gaps 41. Capsule 43 may be burned or cut away to
create notches 9.
[0118] FIG. 6V with cross section FIG. 6V-1 depicts an embolic
agent 1 with repeating segments 52 of helical wire 33, which may be
composed of electrolytically corrodible metal with a coating 31 as
depicted, or with a non-corrodible metal in variation. The segments
52 are connected by connectors 35 composed of electrolytically
corrodible metal which is non-detachably bonded to the internal
surface 54 of the helical wire 33. The coating is absent for enough
helical wire 33 to create an intrinsic electrical contact 51 with
the connector 35, and external surface 42 of helical wire 33 has
coating or non-conductive adhesive 50 so that the only exposed
surface of connector 35 is the bare portion 39 between segments 52
of helical wire 33. The bond between the connector 35 and more
distal segment 52 of helical wire 33 includes insulating coating 31
on helical wire 33 to prevent electrical contact 51 with the
connector 35, which may further be prevented by a coating 31 around
the surface of the involved portion of the connector 35. Said bond
may be created by non-conductive adhesive 50 or other conventional
means. The operator may remove a portion of coating 31 from the
proximal segment 52 of helical wire 33 to apply current, which will
be conducted to the bare portion 39 of the connector 35 serving as
the detachment point 28. Conduction may not occur to more distal
connectors 35 which will not undergo electrolytic corrosion.
[0119] FIG. 6W with cross section view FIG. 6W-1 depicts an embolic
agent 1 with repeating segments 52 of helical wire 33 composed of
electrolytically corrodible metal with a coating 31. The segments
52 are connected by connectors 35 composed of dielectric material
which is non-detachably bonded to the internal surface 54 of the
helical wire 33, in this example by non-conductive adhesive 50
although other conventional means could be used. The coating is
absent on a bare portion 39 of the helical wire 33 slightly
proximal to the connector 35. The operator may remove a portion of
coating from the extracorporeal proximal segment 52 of helical wire
33 to apply current, which will be conducted to the bare portion 39
of the helical wire 33 serving as the detachment point 28.
Conduction may not occur to more distal segments 52 which will not
undergo electrolytic corrosion.
[0120] FIG. 6X and cross sections views FIGS. 6X-1 and 6X-2 depicts
an embolic agent 1 with a continuous electrolytically corrodible
wire 6 covered on most of its length by a coating 31 except for a
bare portion 39 which serves as an electrical contact 36 near the
proximal end 18. Segments 52 of tubing 55 with a wall 2 and a
hollow portion 22 surround the wire, with alternating repetition of
attached versus non-attached segments 52. Approaching the distal
end 19, a metallic marker 13 is swaged onto the tubing 55, thereby
gripping the wire 6, creating a fixation point 29 between wire and
tubing 55 to prevent sliding motion between them. In the middle
portion 20, the segment 52 of tubing 55 is not fixed to the wire 6
and may slide, constrained only by butting against adjacent fixed
segments 52. These segments 52 of tubing 55 add bulk and body to
the embolic agent 1. Near the proximal end 18, attachment at
fixation point 29 is achieved without swaging, and instead may be
bonded by adhesive, heat shrinking, heat melting, or other
conventional means. Two different types of fixation 29 are shown
only for demonstration means and it is likely that only one type of
fixation means would be employed for all fixation points 29.
Current may be applied to extracorporeal contact 36, and detachment
28 will occur at one of potential detachment points 28 which was
stripped of coating 31 by operator as described herein.
[0121] FIG. 6Y and cross section 6Y-1 depicts an embolic agent 1
with similarities to that depicted FIG. 6X but utilizing segments
52 of helical wire 33 instead of tubing 55. The segments 52 of
helical wire 33 are protected from electrification and hence
electrolytic corrosion by a coating 31 on the straight wire 6 and
detents 56 that are roughly disc-shaped in this depiction and, in
variation may be other shapes, said detents 56 being non-detachably
and non-slidably attached to the wire 6 using solder, adhesive,
compression, or other conventional means. Said segments 52 surround
the straight wire 6 which occupies the space inside 34, but said
segments 52 are not attached and may slide on the wire, being
detained only at the detents 56, providing flexibility to the
embolic agent 1. Corrodible wire 6 is covered on most of its length
by a coating 31 except for a bare portion 39 which serves as an
electrical contact 36 near the proximal end 18. Current may be
applied to extracorporeal contact 36, and detachment 28 will occur
at one of potential detachment points 28 between detents 56 which
was stripped of coating 31 by operator as described herein (shown
here before stripping). In variation, easily removable seal 46 as
described in FIG. 6J may be utilized in the space between the
paired detents 56 to facilitate operator modification.
[0122] FIGS. 7A-C are each sequential frontal views depicting
embolic agents 1 and very simple mechanical methods of detachment
using extra-corporeal modification by the operator. In FIG. 7A, an
embolic agent 1 comprised of a simple long monofilament 5 undergoes
the "cut and retract" method. On the left, embolic agent 1 is seen
extending throughout the introducer catheter 200 from the proximal
end 206 to the target tissues (not shown) beyond the distal end 210
of the introducer catheter 200, where the distal end 19 of the
embolic agent 1 is coiled in a helix. In this figure, it is now
being retracted by pulling on the proximal end 18, as shown by the
arrow, thus removing some a portion of the embolic agent 1 from the
target tissues, back into the extracorporeal operating field
proximal to the proximal end 206 of the introducer catheter 200. In
the middle figure, the embolic agent 1 is being cut by an embolic
detachment tool 160, which is a pair of scissors. In the same
figure, an introducer sleeve 216 with a flared end is slipped over
the severed end of the embolic agent 1 as shown. The introducer
sleeve 216 is then pulled down so that the severed end of the
embolic agent 1 is inside it (not shown). Then, a pusher element 90
may be brought into the flared end of the introducer sleeve 216,
where its tip 94 will abut the embolic agent 1. The embolic agent
1, pusher element 90 (not shown until third drawing in sequence),
and introducer sleeve 216 may all now be pushed in unison until the
introducer sleeve 216 abuts the hub 201 of the proximal end 206 of
the introducer catheter 200. Then, the introducer sleeve 216 will
remain stationary as the severed end of the embolic agent 1 is
pushed inside the introducer catheter 200, and the introducer
sleeve 216 may now be slipped off the proximal end 91 of the pusher
element 90 and discarded. Now, as seen on the right, the tip 94 of
the pusher element 90 pushes the embolic agent 1 through the
introducer catheter 200 to the target tissues as indicated by
curved arrow. The pusher element 90 is now easily removed by
retraction. This technique will leave the desired amount of embolic
agent 1 within the tissues as determined before retraction and
severing. This permits deployment of desired amount of embolic
agent 1 while utilizing severing or detachment techniques outside
of the body rather than close to the target tissues, as described
elsewhere herein, and serves as simple and economical way to use
the described embolic delivery systems to administer embolic agents
that are much longer than conventional agents.
[0123] FIG. 7B shows a method of detachment of the embolic agent 1
that permits repositioning of the embolic agent 1 after
modification by operator, but prior to detachment, with option to
detach when detachment point 28 is positioned in the target tissues
beyond the tip 211 of the introducer catheter 200. On the left, the
distal end 19 of the embolic agent 1, which is a non-metallic
monofilament 5 in this example, is partially deployed in the
abnormal tissues, while the proximal end 18 is seen proximal to the
introducer catheter 200, which also has proximal 206 and distal 210
ends. In the figure on the left, it is determined that the amount
of embolic agent 1 that is deployed in the tissues is the ideal
amount. To detach it with this extent of embolic agent 1 in the
tissues, the embolic agent 1 is first retracted by pulling down on
the proximal end 18 as indicated by the arrow, which results in the
partial retraction of the distal end 19 as shown by the curved
arrow. Once the embolic agent 1 has been retracted a distance
approximately equal to the length of the introducer catheter 200
(middle drawing), then it is scored with the scoring tool 163,
which cuts a fine score around the circumference of the embolic
agent 1 but does not cut through its entire diameter. The embolic
agent 1 is now weakened, but intact at the detachment point 28. It
may now be pushed by the operator into the introducer catheter 200
as indicated by the arrow, which pushes the distal end 19 back into
the tissues as they were before retraction and scoring. Once the
scored portion has exited the introducer catheter 200 (drawing on
right), the proximal end 18 of the embolic agent 1 is rotated by
the operator or equipment controlled by the operator. Since the
distal end 19 will not easily rotate due to extensive deployment
and nesting, there will be twisting forces on the weakened score
zone, resulting in complete detachment. Now, the proximal portion
18 of the embolic agent 1 may be removed and embolization is
complete. Alternatively, the embolic agent 1 may not need to be
retracted prior to scoring. The final length may be estimated, and
the score may be applied, then the embolic agent 1 may be pushed in
and twisted off.
[0124] FIG. 7C shows a method of detachment that permits
repositioning of the embolic agent 1 after extracorporeal
modification, consisting of weakening by stretching, by operator
prior to detachment, with option to detach when detachment point 28
is positioned in the target tissues beyond the distal tip 211 of
the introducer catheter 200 as seen in FIG. 7B. The embolic agent 1
is a monofilament 5, which can be stretched when grasped and pulled
apart, as shown by the arrows. This results in a weakened, narrow
portion as seen on right. This permits pushing and retraction of
the distal portion 19 when the proximal end 18 is manipulated by
the operator. As in FIG. 7B, it is detached by twisting the
proximal portion 18 until it breaks at the detachment point 28.
This weakening may be enhanced by scoring as seen in FIG. 7B. In
variation, there are transitions at regularly spaced locations
along the embolic agent 1 where the material is more susceptible to
stretching and weakening. These areas may also serve as extra
flexible areas for nesting.
[0125] FIG. 8A-11C depict detachment systems for embolic agents
which do not rely mainly on electrolytic means and are
predominantly mechanical, although may additionally include
electrolytic means. FIG. 8A is a longitudinal section view (left)
and a 4 part sequential perspective view (right) teaching basic
concepts of mechanical detachment and depicting a specific embolic
agent 1 and pusher element 90 with a screw-type detachment
permitting a controlled advancement or retraction of the embolic
agent 1 via the pusher element 90 under operator control. The left
drawing shows a longitudinal section of the distal end 92 of the
pusher element 90, containing traction elements 270 in form of
threads 276, which are specially designed to interface as shown
with the inner hollow space inside 34 at the proximal end 18 of the
embolic agent 1, which is a helically wound wire 33. In the
sequential drawings beginning with the first drawing, a pusher
element 90, introducer catheter 200, and embolic agent 1 are shown,
where the dotted arrow indicates that the distal end 92 of the
pusher element 90 is inserted into the space inside 34 of the
helical wire 33, which may have been severed as described herein to
the appropriate length by the operator. The distal end 92 of the
pusher element 90 has traction elements 270 consisting of threads
276, similar to threads on a screw or bolt, which mate with the
pattern on the internal surface 54 of the embolic agent 1.
Progressing to sequence on the right, the pusher element 90 is
rotated and screwed into the embolic agent 1 which is not rotated,
thus resulting in the pusher element 90 advancing into and becoming
rigidly attached to the embolic agent 1. The operator may now
advance the pusher element 90 and therefore the embolic agent 1
into the lumen 209 of the introducer catheter 200, thereby
providing a firmer attachment of pusher element 90 to embolic agent
1 by constraining the helical wire 33 from expanding or spreading
apart, since the internal diameter of the lumen 209 is very
slightly larger than the outer diameter of the embolic agent 1.
Now, the embolic agent 1 may be advanced or retracted by
manipulation of the pusher element 90 by the operator directly or
indirectly. In this example, the control over the embolic agent 1
persists even after the embolic agent 1 has been extruded
completely past the distal end 210 of the introducer catheter 200
into the target tissues, and is no longer constrained within the
lumen 209 of the introducer catheter 200. The third sequential
drawing shows the pusher element 90 being unscrewed from the
embolic agent 1 with a counterclockwise rotation about its long
axis (depicted by arrow). The pusher element 90 may then be
removed. Prevention of corresponding rotation of the embolic agent
1 which might prevent unscrewing would usually be accomplished due
to the substantial extent of the length of embolic agent 1 deployed
in the target, usually in a bent, kinked, or curved manner,
providing for some degree of resistance to rotation of the embolic
agent 1 about its long axis. Partial rotation of the embolic agent
1 could still result in dissociation since the pusher element 90
could be rotated freely, so rotations could be continued until
dissociation occurred. In the final drawing of the upper sequence,
the pusher element 90 has been removed, and a different pusher
element 90, in this example a conventional helical wire 33 is
passed into the introducer catheter 200 to push the embolic agent 1
beyond the distal tip 211 of the introducer catheter 200 to the
target tissues, moving in the direction shown by the dashed arrow.
In variation of method where the threaded pusher element 90 was
used to push the embolic agent 1 all the way to the target tissues
before dissociation took place, this final step would not have been
necessary.
[0126] FIGS. 8B-C depict embolic agents permitting operator to
determine the length of detached embolized segment with precise
operator-determined placement near the tip 211 of the introducer
catheter 200 without requirement for operator modification, and
have mechanical, lockable components. FIG. 8B is a sequential
series depicting a locking detachable embolic agent 1 using a
conventional type of locking mechanism 10 in a novel series of
repeating segments 52. This embolic agent 1 is shaped roughly
similarly to most described herein; round in cross section and long
and narrow. Its body 40 is depicted as a monofilament 5 but in
variation it could be a helical wire 33. It has repeating segments
52 with locking mechanisms 10. This causes locking of the segments
together when constrained inside an introducer catheter 200 or an
introducer sleeve 216. As seen on the left, a two dimensional
frontal view with a magnified portion shown in exploded view, the
embolic agent 1 is constrained within an introducer sleeve 216, and
the locking mechanism 10 locks the repeating segments 52 together.
In the second figure, a lower perspective view, the embolic agent 1
is seen being driven into the introducer catheter 200 by feeder
rollers 325 of the embolic delivery system 324. Before entering the
feeder rollers 325, the embolic agent 1 is restrained in the
introducer sleeve 216, in which it can easily slide forward or
backward, but cannot unlock because the components of the locking
mechanism 10 are constrained by the walls of the introducer sleeve
216. In the third drawing, one segment 52 is nearly deployed in the
tissues beyond the distal end 210 of the introducer catheter 200,
but is still locked. The final drawing depicts the disconnection of
the locked elements of the locking mechanism 10 of the embolic
agent 1 once pushed into the target tissue, where it is no longer
constrained in the introducer catheter 200. Variations of the
locking embolic agent 1 are many, and include a different
configuration of locking mechanism 10 that would serve the same
purpose, and use of many different types of composition materials.
As with other embolic agents, the shape and proportions of the
system may vary.
[0127] FIG. 8C is a sequential view of a lockable detachable
embolic agent 1 which does not have repeating segments and is
modified by the operator prior to detachment. It permits detachment
at any location of the embolic agent chosen by the operator. On the
left, an embolic agent 1 has already been cut from a very long
continuous embolic agent provided by manufacturer, consisting of a
flexible tube 55 with a hollow lumen 7, a wall 2, and periodic
markers 13, one of which is seen at the proximal end 18. In
variation, it could have a reinforced wall as described herein. In
the second drawing, a pusher element 90 has been inserted into the
lumen 7 of the proximal end 18 of the embolic agent 1, creating a
friction lock, and then embolic agent 1 and pusher element 90 have
been advanced in unison beyond the distal end 210 of the introducer
catheter 200. The pusher element 90 consists of a relatively stiff
wire 100 which may be removably inserted into a long hollow tube
101 whose lumen 97 snugly accommodates the wire 100 as shown,
tapers at the distal end 92 so that insertion of the wire 100 to
the distal end 92 will result in very slight increase in outside
diameter of the tube 101 to create a friction attachment to the
lumen 7 of the embolic agent 1, permitting control over the embolic
agent by the operator while it is intra-corporeal. The tube 101 of
the pusher element 90 has a blunt, closed distal end 92, and is
relative stiff, but flexible enough to pass around curves. In the
third drawing, the wire 100 has been withdrawn from the tubing 101
of the pusher element 90 by the operator extra-corporeally.
Relative stiffness and reinforcement of the tubing 101 helps
facilitate this maneuver. With the wire 100 removed, the distal end
92 of the tubing 101 is now more flaccid and is easily removed from
the lumen 7 of the embolic agent 1, leaving the embolic agent 1 in
the desired tissues in the body, while all other components may be
retrieved extra-corporeally by the operator as seen in the fourth
drawing.
[0128] FIGS. 8D-G introduce a novel linking element 110 which is
integrated with a detachment element 120 containing traction
elements 270 for attachment of an embolic agent to a pusher
element, which may be installed onto the embolic agent by the
operator, permitting customization of its length and permitting
precise detachment near or beyond the distal end of the introducer
catheter. FIG. 8D is a perspective view showing 6 examples of
linking element 110 which is integrated with a detachment element
120 which are bi-directional locking elements 122, made of a solid,
rigid material such as metal or hard plastic, which may be attached
to an embolic agent 1 and a pusher element 90 by the operator, so
that the two may be locked together or detached as desired,
functioning similarly as seen in FIG. 8B. These differ from
conventional bi-directional locking elements which are not
modifiable by the operator and therefore not allowing
operator-determined length of embolic agent 1 as described for this
invention. In FIG. 8D, the bi-directional locking elements 122 have
an attachment pin 113 which is used to detachably attach to a
pusher element 90 and/or embolic agent 1 as shown in FIGS. 8E-F.
Secure attachment is aided by the following traction elements 270
depicted in clockwise direction in FIG. 8D: barbs 273, no traction
elements, ridges 272, curved attachment pin 113, roughness 271, and
threads 276. Rapid curing adhesive may also be applied by the
operator to attachment pin 113. FIG. 8E is a longitudinal section
view and FIG. 8E-1 is a cross section view of a linking element 110
which is integrated with a detachment element 120, depicted after
attachment to the hollowed out end of the pusher element 90 by the
operator extra-corporeally, so that the linking element 110 with
attachment pin 113, bi-directional locking element 122 with pin
113, and the embolic agent 1 may now function as one unit. The
linking element 110 is linked to another bi-directional locking
element which is rigidly attached to a pusher element 90, so that
all elements may now act in unison with control by the operator
while the linking elements 120 are constrained inside an introducer
catheter and thereby locked together similar to depicted in FIG.
8B. The embolic agent 1, linking element 110, and one of the
detachment elements 120 are detached from the other detachment
element 120 and pusher element once pushed beyond the end of the
introducer catheter. In the longitudinal view of FIG. 8F and the
cross section view of FIG. 8F-1, the bidirectional locking element
122 with pin 113 of the linking element 110 is similarly attached
to the lumen 7 of a tubular embolic agent 1. Since it is tubular,
it does not need to be hollowed out by operator prior to attachment
of its function is otherwise similar to FIG. 8E. The devices in
FIG. 8E-F function similarly to the schematic representation in
FIG.
[0129] FIG. 8G is a sequential perspective views that depict the
use of the linking element 110 which integrates with detachment
element 120 of FIGS. 8D-F in conjunction with an embolic agent 1
consisting of a helical wire 33, and a pusher element 90 also
consisting of a helical wire 33, and method of use for advancement
or retraction and controlled detachment in conjunction with an
introducer catheter 200 and an introducer sleeve 216. A helical
wire embolic agent 1 is seen extending through the entire length of
the lumen 209 of an introducer catheter 200. This has a hollow
space inside 34, although in variations may have a mandrel wire or
other agent in its space inside 34. The proximal end 18 of the
embolic agent 1 is seen, having been severed by the operator using
cutting tools described herein or being the natural end of the
manufactured embolic agent 1. The attachment pin 113 is inserted
into the space inside 34 of the embolic agent 1 and secured using
any of the means described herein. The introducer sleeve 216, which
is a rigid or minimally flexible tube with a flared end is advanced
over the embolic agent 1 yielding the configuration seen in the
second figure in the sequence. Now the pusher element 90 is
introduced, with the bi-directional locking element 122 of the
linking element 110 secured in its distal end 92, either by the
operator, or by the manufacturer. As shown by the arrow, it is
mated with the bi-directional locking element 122 attached to the
embolic agent 1, as seen in the third figure of the sequence, where
it can also be seen that the flared end of the introducer sleeve
216 has been slid down over the mated elements so as to constrain
them in its lumen 209 so they will stay locked together. Now, as
indicated by the arrow, the operator may push the pusher element 90
forward, while simultaneously advancing the mated embolic agent 1,
and the introducer sleeve 216 until the introducer sleeve 216 abuts
the hub of the proximal end 206 of the introducer catheter 200. As
seen by the arrow, the pusher element 90 is advanced forward, and
as indicated by the other arrow, the introducer sleeve 216 is now
slid down the pusher element 90, out of the figure thus yielding
the final drawing where the embolic agent 1 is seen inside the
introducer catheter 200, where the bi-directional locking elements
122 remain constrained and locked together. Further advancement
(not depicted) will result in deployment of the embolic agent 1 in
the target tissues, where now unconstrained, the locking elements
122 may dissociate and the pusher element 90 may be retracted and
retrieved as described elsewhere herein.
[0130] FIG. 8H is a sequential longitudinal section depiction, with
exploded view, of another embodiment of a linking element 110 which
is integrated with a detachment element 120 having traction
elements 270 which are screw threads 276. The attachment pin 113 in
this example has screw threads 276 to help it attach to the embolic
device 1 which also has corresponding traction elements 270 of
screw threads 276, although any of the variations of attachment pin
shown in FIG. 8D are possible here as well including rapid curing
adhesive, permitting the use of an embolic agent 1 which does not
have screw threads. If screw threads 276 are used on the attachment
pin 113, then they may be oriented in the usual manner, or in the
opposite direction as shown, such that it would be tightened using
counter-clockwise rotation. This might be done so that
counterclockwise rotation of the pusher element 90, performed with
intention to detach it with detachment element 120, will not result
in inadvertent loosening of the linking element 110 from the
proximal end 18 of the embolic agent 1. Extra-corporeally, the
operator may first screw the linking element 110 into the proximal
end 18 of the embolic agent 1, and then screw the distal end 92 of
the pusher element 90 into the detachment element, which has
traction elements 270 of screw threads 276 to mate with the
corresponding screw threads 276 of the detachment element 120. When
release of the embolic agent 1 into the target tissues is desired,
the pusher element 90 may be rotated counter-clockwise, thus
disengaging it from the detachment element 120 and the linking
element 110, which stay attached to the embolic agent 1 as it
remains in the target tissues.
[0131] FIG. 8I is a longitudinal section view of another variation
of a detachment element 120 and a linking element 110 that offers
an overall shape different from a simple straight-line
configuration in order to facilitate nesting into tissues or
prevent tissue perforation. The attachment pin 113 is curved, in
this example into a gentle right angle, near its junction with the
wider portion that uses screw threads 276 for attachment, although
any other traction element 270 described herein may be used. The
attachment pin 113 is flexible and elastic, allowing it to be
straightened when constrained inside the lumen of an introducer
catheter (not shown). It will resume its memory shape of the
depicted curve once deployed in the tissues. It may be composed of
heat sensitive Nitinol which becomes more rigid after warming to
body temperature. The rounded shape minimizes risk of trauma or
perforation to tissues.
[0132] FIG. 8J is a sequential longitudinal section view depicting
a variation of a linking element 110 that is intended to reduce
possible trauma to the wall of a vessel or other body part. On the
left, a detachment element 120 with the traction elements 270 screw
threads 276 one end, integrates with a linking element 110 having
an attachment pin 113 with traction elements screw threads 276. The
linking element 110 is shown in exploded view to be inserted by the
operator into the proximal end 18 of an embolic agent 1 that has a
wall 2 around a round space inside 34. On the right, the assembly
is depicted. The curved attachment pin 113 imparts a gentle curve
to the proximal end 18 of the embolic agent 1 when in the resting
state with no external forces applied. This may have positive
implications when resting in tissues, where the gentle "J" shaped
end is less likely to jut against the tissues and cause
perforation. The curved attachment pin 113 is composed of a highly
flexible and elastic compound, such as types of stainless steel or
Nitinol; however, so that when the depicted assembly is inserted
into the lumen 209 of an introducer catheter 200 (not shown here)
as described elsewhere herein, it will straighten out to allow
passage through the lumen 209. Once deployed beyond the tip of the
introducer catheter 200, it will resume its memory shape of a curve
as shown. Although the "J" shape is depicted, there are many other
shapes consistent with this invention that will also serve the
function of preventing a straight-line configuration, and thereby
reduce the likelihood of tissue perforation.
[0133] FIGS. 8K,M and N are longitudinal sectional depictions
pertaining to embolic agents 1 using threaded detachment elements
120 where the traction element 270 threads 276 of adjacent
detachment elements 120 have reversed orientations relative to each
other, decreasing ideal distance between detachment points 132, and
not requiring modification by operator prior to detachment. In FIG.
8K, the embolic agent 1 is a flexible monofilament 5 with many
interlocking repeating segments 52 having the following pattern,
from proximal 18 to distal 19: metallic female component 135 of
detachment element 120 non-detachably attached to non-metallic
monofilament 5 by an attachment pin 121, said monofilament 5 then
non-detachably attached to the final component of the repeating
segment 52 which is a metallic male component 134 of detachment
element 120. Detachment elements 120 utilize the traction elements
270 of threads 276 for locking of male component 134 and female
component 135 together. Although segments 52 repeat, each adjacent
segment 52 has opposite orientation of the screw threads 276 of the
detachment element 120, and will therefore detach using opposite
rotational directions. Therefore, when the operator controls the
proximal portion 18 of the embolic agent 1 extra-corporeally, they
may choose which of the next two detachment sites 132 will detach
based on which direction of rotation is used. FIG. 8L demonstrates
that the novel design described in FIG. 8K permits the spacing of
the distance (labeled as "d") between detachment sites 132 to be
less than the length (marked as L) of the of the introducer
catheter 200 when operator intends for detachment site 132 to be
beyond distal tip 211 of the introducer catheter 200, so long as d
is greater than 1/2 L. Shorter segment lengths may enable more
precise control of embolization. In variation metallic locking
mechanisms would not be present and instead the threads would be
manufactured into the monofilament segments themselves if using a
substance providing sufficient hardness for effective attachment.
FIG. 8M depicts an embolic agent 1 of similar description as FIG.
8K except using helical wire 33 in FIG. 8M instead of monofilament
5 as in FIG. 8K. Like FIG. 8K, the detachment elements 120 on
adjacent segments 52 have opposite orientation of threads 276 and
permit the functionality described in FIG. 8L. FIG. 8N depicts
further variation of FIG. 8M in that the non-detachably attached
female component 135 of FIG. 8N is not present, and instead in FIG.
8N the internal surface 54 of the helical wire 33 function as the
female component of the detachment element 120, with similar
function as in FIGS. 8K and 8M. Also in FIG. 8N, there may be weld
points 21 in the helical wire 33 at the site of mating with the
male component 134 of the detachment element 120 of the adjacent
segment 52, in order to prevent spreading of the wire coils which
might decrease the strength of the lock. Because the embolic agent
1 will not typically be rotated during phase of its advancement
through the introducer catheter 200 (not shown), the locking
mechanisms 122 may all be secured rather loosely at the time of
manufacture, so that little rotational force will be required at
the time of desired detachment 132.
[0134] FIG. 8O is a sequential representation of a detachment
mechanism using a detachment element 120 which includes a tube 124,
and is used in conjunction with a pusher element 90. The embolic
agent 1 has operator-determined variable length and infinite
choices of detachment sites 132. The long embolic agent 1 is
severed and further modified by the operator using an embolic
detachment tool 160 which narrows the proximal end 18, so that it
will fit snugly into the distal end 92 of the tube 124 of the
detachment element 120. Cutting and modification are not shown in
this figure but are described herein. The first drawing on the left
depicts an optional stabilizer 169 which is an embolic detachment
tool 160 element consisting of 2 flat solid plates with a
stabilizer groove 170 having friction surfaces, and extending
longitudinally along the surface of each plate and forming a round
channel when the plates are pressed together (horizontal arrows)
and merged as shown, to stabilize the pusher element 90 and the
embolic agent 1 so that the former can be inserted into the latter
(direction of vertical arrows) without bending or difficulty.
Alternatively the operator will simply use their fingers. Once
inserted as seen in the middle figure, the pusher element 90 can
now be used to advance or retract the embolic agent 1 within the
introducer catheter (not shown). Detachment 132 is seen in the
third drawing on the right. The pusher element 90, which may be a
conventional wire 100 is inserted by the operator into the lumen 97
of the proximal end 91 pusher element 90 and advanced until its tip
94 abuts the embolic agent 1. This may provide more stiffness in
advancing the embolic agent 1. Once detachment 132 is desired, the
pusher element 90 is advanced while holding the tubing 124 static,
pushing the embolic agent 1 out of the tip 94 of the pusher element
90 as shown, showing a wire 100 could be advanced with some force
when it abuts the proximal end 18 of the embolic agent 1, thus
pushing the embolic agent 1 out of the tip 125 of the tube 124 and
the embolic agent 1 out of the tube 124 thereby detaching it from
the detachment element 120. FIG. 8P is a frontal view depicting an
embolic agent 1 that has operator-determined variable length and
infinite choices of detachment points 132 using hydraulic pressure.
It is shown with a pressure generator 172, in this case a syringe
653. The description of device and use is the same as FIG. 8O until
the third drawing in the sequence, when detachment differs in that
hydraulic pressure is used to force the embolic agent 1 out of the
tip 125 of the tube 124 thereby detaching it from the detachment
element 120.
[0135] FIG. 8Q is a 2 part sequential series with 3 dimensional
frontal views and cross sectional views FIG. 8Q-1 and FIG. 8Q-2 of
a detachable embolic system 1, plus a single 3 dimensional view of
a variation of the detachment element 120. It depicts an embolic
agent 1 that has operator-determined variable length and infinite
choices of detachment points 132 when combined with a detachment
element 120 using hydraulic pressure differently than FIG. 8P. FIG.
8Q shows, beginning on the left, an embolic detachment element 120
which is a smooth flexible tube composed of a polymer, possibly
with very fine metal wires reinforcing its wall 136 in a
conventional manner, containing a central hollow lumen 126 and
integrated with a pusher element 90, with a hub 102 on its proximal
end 91. The detachment element 120 has a closed, solid tip 125. The
lumen 126 passing through the integrated pusher element
90-detachment element 120 is fluid-tight except for the opening at
the hub 102 of the proximal end 91, which may be connected to
syringe 653 for injecting fluid to create increased pressure within
the lumen 126. On the distal end 139 a balloon 137 is located, that
is in continuity with the lumen 126 and may therefore be filled
with fluid or saline under pressure, thus expanding its diameter.
In an example of a variation seen on the bottom right view a
detachment element 120, instead of a balloon, the distal end 139
may simply have a wall 136 that is composed of a compliant
material, while the middle 93 and proximal end 91 of the pusher
element 90 are composed of a non-compliant material. In this
variation, compliant distal end 139 of the detachment element 120
would swell in diameter upon application of hydraulic pressure into
the lumen 126, and thus serve a similar purpose as a balloon. The
detachment element 120/pusher element 90 may have a combination of
rigidity and flexibility that allows pushing around bends, and
which may have a transition between more rigidity in its proximal
end 91 relative to a more flexible distal end 139. In variations,
it could have a variety of compositions. The figure in the middle
shows the detachment element 120 inserted into the hollow lumen 7
of the embolic agent 1 at its proximal end 18, which has been
severed using means described herein, or is the natural proximal
end 18 of the embolic agent 1 as manufactured. Then, progressing
through the sequence as indicated by the solid arrow, the hub of
the syringe 653 is connected to the side port 535 of the side-port
adaptor 530, and the hub 532 of the side port adaptor 530 is
attached to the hub 102 of the proximal end 91 of the pusher
element 90. A conventional pressure manometer may be included to
provide predictable inflation pressures. In this figure, a small
diameter guide wire 550 is shown extending through the entire
length of the lumen 126 of the pusher element 90 and detachment
element 120, with its distal tip 552 as shown, and then extending
proximally out through the lumen 541 of the side port adaptor 530,
through its O-ring 537, and further proximally into the environment
where its proximal end 551 is located and available for
manipulation by the operator. This guide wire 550 represents an
optional element that the operator may or may not choose to advance
into position as shown, in order to provide additional stiffness to
the detachment element 120 in order to facilitate its function as a
pusher 90 or retractor of the embolic agent 1. Because the O-ring
537 of the side port adaptor 530 may be tightened around the guide
wire 550, the seal is fluid-tight and pressure may still be
transmitted from the syringe 653 to the balloon 137 or the
distensible distal end 139 of the detachment element 120. Now that
all the connections are secured, fluid or gas is injected by the
syringe 653 as indicated by the solid arrow, or by other
conventional means, to generate hydraulic pressure in the lumen 126
and the balloon 137. The balloon 137 [or compliant distal end 139
of detachment element 120 if described variation is used], is seen
to swell in diameter, thus pressing outwardly against the inside of
the hollow embolic agent 1, which does not itself stretch
substantially radially due to the tensile strength of its wall 136
reinforcement, providing friction grip. This makes the detachment
element 120 essentially function also as a pusher element 90,
allowing operator to deposit the embolic agent in the target
tissues beyond the tip 211 of the introducer catheter 200, at which
time the pressure can be released from the syringe, or made
negative by retraction of the plunger of the syringe, to deflate
the balloon 137 or the distended wall 136 of the distal end 139 of
the detachment element 120 (depending on whether first embodiment
or described variation is used). Detachment element 120 may now be
removed. In variation, a helical wire 33 with a hollow space 34
inside as described herein may be used instead of a tubular embolic
agent 1 with same overall effect as described in FIG. 8Q.
[0136] FIG. 8R depicts two variations of an embolic agent 1 that
has operator-determined variable length and infinite choices of
possible detachment sites, using hydraulic pressure to provide
turgidity, while permitting a hollow lumen 7 throughout most of the
embolic agent 1 to be used as part of a variety of detachment
mechanisms described in this invention. On the left, the embolic
agent 1 is a very long tube 55 with a hollow lumen 7, in this case
reinforced by conventional helical wire 33 imbedded within its wall
2, although other conventional reinforcement structures used in
catheters may be used in this embolic agent 1, where the use of a
reinforced tubular structure is novel. The great flexibility of
this hollow tube is an advantage for nesting in abnormal tissues,
but it benefits from extra stiffness gained from hydraulic pressure
during advancement by the embolic delivery system. The tip 57 is
closed, and the only opening is via the proximal hub 58. It is
shown with a pressure generator 172, in this case a syringe,
attached to its proximal hub 58 with a pressure meter 173
interposed, indicating the pressure in the lumen 7 of the embolic
agent 1 created by the fluid 60 in the pressure generator 172 and
lumen 7. The pressure generator 172 may have been applied by the
operator at the time of the procedure. In variation, as seen on the
right, there would be no pressure generator 172 or pressure meter
173, and instead the proximal end 18, and thereby the entire
embolic agent 1, would be packaged by manufacturer with a
fluid-tight seal throughout, with pressurized fluid 60 filling the
lumen 7 and providing the optimal pressure for purposes herein. The
pressurization provides turgidity and increased stiffness of the
embolic agent 1 so that it may have the desired properties for
advancement by the embolic delivery system (not shown) as described
herein. Once the desired length of embolic agent 1 has been
deployed within the body, the embolic agent 1 may be severed extra
corporeally creating a new proximal portion with an accessible
lumen 7 as described in this invention. Pressure will be lost
within the embolic agent 1, however it is no longer necessary since
the last portion will not be advanced using the embolic delivery
system 1 but instead will be advanced manually, after attachment of
any of the many detachment elements and pusher elements described
herein. The entire embolic agent 1 is advanced into the tissues,
detached, and other elements removed as described in this
invention.
[0137] FIG. 9A includes four frontal sequential views, and many
cross section views FIGS. 9A-1 to 9A-4 and 9B-1 to 9B-4 depicting
an operator-controlled linking element 110 that may be used to link
a wide variety of embolic agents to a wide variety of types of
detachment elements, providing versatility and broadening of
applications for many elements. On the left, several elements are
shown and are included in cross section FIGS. 9A-1 to 9A4 before
linking as they might be experienced by the operator in the
extra-corporeal operating field. Included is a portion of the
embolic agent 1 consisting of a non-metallic monofilament 5
containing a marker wire 13, the linking element 110, which in this
case is a swage ring 111, a detachment element 120, which is
electrolytic, and a pusher element 90 which transitions
imperceptibly with the detachment element 120. The swage ring 111
is a metallic hollow ring which is amenable to concentric
compression and deformation, thereby bonding and linking other
elements in its center. At the core of the pusher element 90 and
the detachment element 120 is an electrolytically corrodible wire
128 which is continuous throughout the detachment 120 and pusher 90
elements and available for electrical contact proximally in the
operating field extracorporeally at the contact point 103. In the
detachment element 120, the wire 128 is surrounded and electrically
insulated by a dielectric semi-rigid capsule 131. Progressing more
proximally, the wire 128 is not insulated at the short bare portion
130, which serves as the detachment point 132. Proximal to the bare
portion 130, in its non-tapered long portion, the wire 128 is
coated with an electrically insulating coating 129. Progressing
more proximally into the pusher element 90, the continuous wire 128
remains coated as seen in FIG. 9A-5 until its proximal end where
there is another bare portion 104 which serves as an electrical
contact 103 to connect to energy source as described in this
invention. In the second drawing, the embolic agent 1 and the
detachment element 120 have both been inserted into opposite ends
of the hollow swage ring 111 by the operator in the operating field
extracorporeally. An embolic detachment tool 160, in this case a
swaging tool 171, is then applied providing concentric compression.
In the third drawing, the swaging tool has been removed, and the
swaged elements are seen linked together securely, with compression
of the swaging ring 111, the embolic agent 1, and the capsule 131.
This is also depicted in cross section FIGS. 9A-6 and 9A-7. The
operator now has complete control of the embolic agent 1 by
controlling the pusher element 90, and may advance or retract the
embolic agent 1 at will even when it has passed into the target
tissues in the body beyond the introducer catheter (not shown).
When proper position of embolic agent 1 is achieved, the operator
may perform electrolytic detachment. Current may be applied to the
wire 128 extra-corporeally at the contact 103, and opposite
polarity charge may be conducted to the ionic medium around the
detachment point 132 using methods described in this invention. The
fourth drawing shows the effects of electrolytic corrosion with
detachment 132 of the detachment element 120 into fragments, with
the upper fragment remaining non-detachably attached to the embolic
agent 1 and the lower fragment remaining non-detachably attached to
the pusher element 90. The swage ring 111 may also serve as a
marker 112 of the end of the embolic agent 1, especially if a dense
metal such as platinum us used.
[0138] FIG. 9B is a two part series which includes cross section
FIG. 9B-1 depicting a variation of the foregoing using a tube-like
embolic agent 1 with a hollow lumen 7. In the first drawing, the
wire 128 of the detachment element 120 extends distally beyond the
capsule 131 as shown, so that when the detachment element 120 is
inserted into the swage ring 111 as seen in the second drawing, the
wire 128 extends into the lumen 7 of the embolic agent 1, and
serves effectively as a mandrel when swaging compression is
performed as described above (not shown). A marker wire 13 is
present in the wall of the embolic agent 1.
[0139] FIG. 9C is a two part 3 dimensional sequential series with
cross sections FIGS. 9C-1 to 9C-8 depicting a variation of FIG. 9A
with reduced components and simpler operation by operator in the
field. The capsule 131 around the corrodible wire 128 in the
detachment element 120 has been omitted, and a non-corrodible metal
is used for the swage ring 111. Electrolytic corrosion may still
only occur at the bare portion 130 detachment point 132. Although
other non-corrodible metals could be used for the swage ring 111,
platinum is used in this figure, and it also serves as a
radio-opaque marker 112 which will remain non-detachably attached
to the proximal end of the embolic agent 1 after swaging, and after
detachment, thereby allowing the operator to know the position of
the entire embolic agent 1 upon detachment. In an embodiment,
omission of the capsule 131 may simplify manufacturing. Also seen
in the first drawing on the left is another variation including the
non-detachable attachment of the proximal portion of the swage ring
111 to the corrodible wire 128. This is shown as having been swaged
on, however other conventional means such as welding, brazing,
soldering, or adhesive could be used. This pre-attachment presents
the operator with fewer separate components and a simpler procedure
to perform in the field. The operator will insert the proximal end
18 of the embolic agent 1 with marker 13 into the swage ring 111
and apply the swage tool (not shown) to achieve the result in the
second drawing, where, as in FIGS. 9A-B, the pusher element 90 and
embolic agent 1 are securely linked by the linking element 110 and
detachment element 120 until operator chooses to perform detachment
as described in FIG. 9A. In variation of FIG. 9C, a dielectric
coating or capsule around the distal end of the wire 128 of the
detachment element, similar to the coating 131 in FIG. 9A, may be
present to prevent electrical conduction from wire 128 to swage
element 111. This would allow use of electrolytically corrodible
metal for swage element 111, or if non-corrodible metal were used,
the coating would decrease the physical size of the electrode
possibly hastening electrolytic corrosion at the intended
detachment point 132.
[0140] For FIGS. 9A-C, in variation, a non-corrodible wire may be
substituted for the coated portion of the corrodible wire 128 to
conduct electricity to the bare area 130 of the corrodible wire
128, using conventional metal-metal connection techniques. In FIGS.
9A-C, an electrolytic detachment mechanism was shown simply for
demonstration purposes, as nearly any other type of detachment
system may be substituted due the versatility provided by this
novel linking method. Many other variations are possible using the
linking element described, as almost any detachment mechanism,
including those of this invention as well as conventional or
described elsewhere, may be easily envisioned to be linked with
nearly any embolic agent by someone experienced in this field,
thereby providing the novel features of this invention including a
variable-length embolic agent whose length is determined by the
operator during the procedure, and whose overall length may far
exceed those of conventional or previously described agents.
[0141] FIG. 9D is a four part sequential series. The first two
drawings are longitudinal sections, and the last two are frontal
views with cross-section views depicted in FIGS. 9D-1 to 9D-8. The
first drawing on the left depicts an embolic agent 1 consisting of
a helical wire 33, with blunt end pieces 61 on both proximal 18 and
distal 19 ends, said end pieces non-detachably connected to the
same straight wire 6, and said end pieces also optionally
non-detachably connected to the helical wire 33 at its proximal 18
and distal 19 ends at what will be called the weld points 21
although solder or other conventional means may be used. This
configuration permits flexibility of the embolic agent 1 while
preventing excessive elongation of the embolic agent 1, which may
be important if retraction is desired by pulling on the proximal
end 18. The embolic agent may be composed of corrodible or
non-corrodible metal but will not be subject to electrolytic
corrosion due to dielectric lining 114 as will be described. This
embolic agent resembles some conventional available agents. In
variation, the wire 6 may be substituted with a non-metallic
strand. In the second drawing, the embolic agent 1 has been severed
by a cutting tool (not shown) by the operator in the operating
field extracorporeally, when the desired length has been
determined, cutting through the helical wire 33 and the straight
wire 6. In the third drawing, the severed embolic agent 1 is about
to be inserted into the cup-like opening of the linking element
110, which is a swage ring 111 that has been pre-attached
non-detachably to the detachment element 120 as in FIG. 9C. In FIG.
9D, an additional component is shown, which is a lining 114 made of
durable, semi-rigid dielectric material that is placed into the
proximal portion 18 of the available space within the swage ring
111 at the time of manufacture. Once inserted into the swage ring
111, the proximal end 18 of the embolic agent 1 will abut the plug
116, which is a compressible dielectric material that sits between
the embolic agent 1 and the distal tip of the wire 128, thereby
preventing current flow from latter to former. The lining will
electrically insulate the embolic agent 1 from the swage ring 111
and the corrodible metal wire 128 of the detachment element 120.
Therefore the embolic agent 1 is not in electrical continuity with
the wire 128. The fourth drawing shows the assembly after swaging
by the operator with swage tool (not shown). All elements are now
linked and advancement and retraction of embolic agent 1 is
achieved by manipulation of pusher element 90, until desired time
to detach using means described in FIGS. 9A-C, including
electrolytic detachment at the detachment point 132 in the bare
portion 130 of the wire 128. In variation, the dielectric lining
114 may extend throughout the entire inside surface of the linking
element 110, thereby providing insulation between the electrified
wire 128 and the swage ring 111, thereby limiting size of electrode
to the bare portion 130 of the wire 128 to possibly hasten its
electrolytic corrosion, and permitting use of corrodible metal for
the swage ring 111.
[0142] FIG. 9E is a series of frontal views of a system and method
utilizing a linking element 110 as shown in FIG. 1I. On the left,
the distal introducer catheter 200 is within the body cavity and
the proximal portion is extracorporeal. Most of the embolic agent 1
is a tube with a wall 2 and a lumen 7 and has been passed into the
body cavity, and the proximal portion has been severed using the
operator using an embolic detachment tool 160 (not shown). The
distal end 92 of a pusher element 90 is attached to a detachment
element 120, which in this example is electrolytic and has a bare
portion 130 of corrodible wire 6 which will serve as a detachment
site 132, and functions as described in this invention. The
detachment element 120 is non-detachably connected to the linking
element 110, which is this example is a round, blunt-tipped rigid
object with a diameter large enough to fit snugly into the lumen 7
of the proximal end 18 of the severed embolic agent 1 without
substantially stretching it. The wall 2 of the embolic agent may be
reinforced to help prevent stretching. The linking element 110 is
attached by the operator to the embolic agent 1, with attachment
optionally aided by traction elements 270 or adhesive (not shown).
As seen in the second drawing, the embolic agent 1 has now been
pushed entirely into the body by the operator by advancing the
pusher element 90, with control over advancement and retraction. In
the third drawing, detachment has been performed at the detachment
point 132, the embolic agent 1 is left in place as the pusher
element 90 and part of the detachment element 120 are removed. In
variation, nearly any type of detachment element such as mechanical
detachment systems described herein, or conventional systems, may
be substituted for the electrolytic detachment mechanism in this
example.
[0143] FIG. 9F and cross-section views 9F-1 to 9F-3 depict a system
that uses a linking element 110 and electrolytic detachment in a
novel manner to enable the novel utilities of this invention. It
also demonstrates a variation for electrolysis where by a second
separate smaller electrical wire 143 is used to carry current
instead of the structural pusher 90. On the left drawing, the very
long embolic agent 1, which is composed of an electrolytically
corrodible wire 6 surrounded and insulated by a capsule 43 as
described in this invention, has already been severed at the
proximal 18 aspect by the operator as described herein. After
severing, a small portion of the capsule 43 at the proximal end 18
was stripped or burned off or otherwise removed as described herein
using detachment tools described later herein, leaving a short
segment of bare 130 wire 128 which constitutes the detachment
element 120. The pusher 90 is shown here as a dielectric
monofilament, although an insulated wire or non-insulated wire
could be used so long as it was not in direct electrical contact
with the linking element 110 (e.g. separated by a dielectric
material). A second insulated electrical wire 143 of very small
diameter passes alongside the pusher element 90 and makes
electrical contact with the linking element 110 which is attached
to the pusher element 90. The linking element 110 is a
non-corrodible metal such as platinum so it will also serve as a
radio-opaque marker 13. Alternatively, it may be a corrodible metal
so long as it would be coated with insulation everywhere except
within the hollow core 115, which is a small round hollow area in
the center of at least a portion of the linking element 110 that
may receive the wire 128 of the detachment element 120 on the
embolic agent 1 and provide electrical contact between the two
elements. Coating 129 of the linking element 110 may be applied in
variation even when using non-corrodible metal composition in order
to prevent inadvertent contact with opposite polarity electrode
contact in an electrolytic introducer catheter as described in this
invention. In the center drawing, the operator has inserted the
wire 128 into the swage ring 111 and swaged it to create a
non-detachable attachment, and also leaving a short distance
between the linking element 120 and the capsule 131 where a short
segment of bare portion 130 of wire is exposed to the surrounding
fluids (not shown). In the third drawing, the operator has applied
current from an electrical source 176 as described elsewhere in
this invention, using a novel electrolytic introducer catheter
described herein (not shown), resulting in corrosion and detachment
at the detachment point 132. This figure represents a relatively
simple yet highly functional detachment system that enables
variable length embolic agents under full operator control and
detachment at the tip of an introducer catheter. Although the use
of the separate insulated electrical wire 143 could be avoided
through use of novel aspects of this invention such as electrified
introducer catheters, it is shown here to demonstrate that the
linking mechanism opens up possibilities for increased detachment
functionality of variable length and multiple detachment site
options even when using more conventional electrolytic means.
[0144] FIG. 9G with cross sections 9G-1 to 9C-4 depict a system
similar to that of FIG. 9F however instead of electrolytic means,
detachment of the embolic agent 1 may be accomplished with nearly
any type of mechanical detachment system in this invention or
elsewhere similar to the manner of FIG. 1I. On the left, the
embolic agent 1, shown partially within the introducer catheter
200, is the same as FIG. 9F except the wire 6 need not be
corrodible, and could be a denser metal serving as a marker 13 as
seen in cross section FIG. 9G-1. Cross section view FIG. 9G-2 shows
The linking element 110 with hollow core 115 of FIG. 9G which is
similar to that in FIG. 9F except in the absence of electrification
in this system, this element and all others may have composition
and interfaces without regard to electrical concerns. The linking
element 110 is non-detachably attached to a detachment element 120.
This detachment element is similar to the interlocking
bidirectional mechanism described herein but in this embodiment is
mainly used to denote nearly any variety of mechanical detachment
system. The second part or the detachment element 120 is
non-detachably attached to the pusher element 90. The second figure
shows the array of elements all now securely linked together while
constrained within the lumen 7 of the introducer catheter 200. The
third drawing shows detachment 132 when desired by operator when
detachment elements 120 are pushed beyond the tip 211 of the
introducer catheter 200. Replacement of the depicted mechanical
element with many other types of mechanical detachment system could
be accomplished by someone skilled in the art using conventional
means.
[0145] FIG. 10A depicts one embodiment of a novel detachment system
using chemical means. On the left is a flexible embolic agent 1,
round in cross section depicted in FIG. 10A-1, composed of a strand
of biocompatible material, in this case a monofilament 5 which is
amenable to dissolution in biocompatible solvent such as dimethyl
sulfoxide (DMSO). This monofilament 5 is surrounded by a capsule 43
of biocompatible material which is not subject to dissolution in
the same solvent. The embolic agent 1 is composed of repeating
segments 52 with bare areas 39 of non-encapsulated monofilament 5
exposed to the environment. The tip 211 of the introducer catheter
200 is positioned in the body cavity (not shown) to be treated and
the embolic agent 1 is advanced to near completion into the cavity.
There is one bare area 39 inside the lumen 209 of the introducer
catheter 200. A side port adaptor 530 is connected to the
introducer catheter 200 in conventional manner to allow injection
of liquid solvent 144 from an attached syringe 653 into the side
port adaptor 530, where it may flow into the lumen 209 of the
introducer catheter 200. A precisely measured volume of solvent 144
is injected, corresponding to the known void space of the lumen 209
of the introducer catheter 200 and side port adaptor 530, in order
to fill the introducer catheter 200 nearly to its tip 211, thus
bathing the bare area 39 with solvent. After an adequate dwell
time, the figure on the right depicts dissolution of the bare area
39 and subsequent detachment 28 of the embolic agent 1 into distal
19 and proximal 18 fragments. The solvent may be aspirated, and the
distal embolic agent 1 fragment may be pushed by the proximal
fragment or by a pusher (not shown) to deposit completely within
the body cavity. This embolic agent 1 and detachment system offers
function similar to shown in FIG. 1G in a system that may be simple
to produce at low cost, and simple to use. In variation, instead of
a monofilament 5, a polyfilament may be used with similar
effect.
[0146] FIG. 11A is a series of drawings representing general types
of detachment mechanisms that have been previously reported. They
are reviewed briefly here to illustrate one of the novel concepts
of this invention, regarding the use of a linking element to enable
the application of conventional detachment mechanisms for use with
a variable-length embolic agent, whereas previously conventional
agents were confined to manufacturer pre-determined lengths when
similar detachment elements were used, as in FIGS. 1E-F. In the
invention disclosed herein, variable-length systems as seen in
FIGS. 1I-K are made possible when using the conventional mechanical
detachment systems of FIG. 11A, or when using novel detachment
systems described in this invention. In each example in FIG.
11A-11C, there is a point of non-detachable attachment 654 to an
embolic agent (not shown) in a conventional system, or to a linking
element (not shown) as in this invention, said linking element
being non-detachably attached to a detachment element 120, and said
detachment element 120 detachably attaches to a second detachment
element 120 which is integrated with a pusher element 90. Referring
back to FIG. 11A, detachment of the two detachment elements 120
occurs, from left to right in the examples, when a wire 128 is
retracted making room for the detachment element 120 to pass beyond
a narrowing in the tube 124 of the detachment element 120, when
hydraulic pressure is applied into the lumen 126 of the tube 124 of
the detachment element 120, when the two detachment elements 120
are pushed beyond the tip of the tube 124 and unhooked from each
other, or when the two detachment elements 120 are unscrewed from
each other. Other types of detachment elements are previously
reported and not shown here, but are nevertheless amenable to
adaptation using this invention as described.
[0147] FIG. 11B and cross section 11B-1 are a representation of a
detachment system using heat sensitive glue which may be used in a
novel manner with this invention by combining with a linking
element (not shown), and a novel electrified introducer catheter as
shown in FIG. 12I, enabling a variable length embolic agent (not
shown). On the left, a pusher element 90 is non-detachably attached
to a detachment element 120, containing a cup 141 with heat
sensitive glue 140 in its bottom, thereby creating a detachable
attachment to the attachment pin 121 of the second part of
detachment element 120, which has a point of attachment 654 to the
embolic agent (not shown) of a conventional device as in FIGS.
1E-F, or the linking element 110 in this invention with
configurations represented by FIGS. 1I-K. The cup 141 is of a
dielectric material with a high melting point, and has a heating
element 181 in its solid portion with sufficient electrical
resistance to become warm enough to melt the glue when charge is
applied. The Wire 128 passes to the outer layers which are two
conductive metal contacts 133 that that are insulated from each
other by a layer of dielectric material 142. These contacts 133
come into contact with the electrical contacts 221 of the
introducer catheter, said contact 221 being attached to an
electrical wire 220 (catheter not shown, wires schematically
represented). This configuration of the introducer catheter 200 is
seen in more detail in FIG. 12I. In the figure on the right,
applying electrical energy (not shown) to the wires 220 of the
introducer catheter 200 will heat the glue 140, melt it, and allow
the attachment pin 121 to detach, thereby releasing the embolic
agent 1 (not shown). Non-detachable attachment of the detachment
element 120 to a linking element 110 (not shown) at the point of
attachment 654 as described in this invention, along with the
electrically active introducer catheter 200 will enable an operator
controlled variable-length embolic agent with full control of
embolic agent via control of pusher element 90 extra-corporeally.
FIG. 11C depicts a variation where there is only one electric wire
220 and one electrical contact 221 in the introducer catheter 200,
and the circuit is completed by having the electric wire 128 of the
detachment element 120 complete a circuit with the electric wire
100 of the pusher element 90, so that the proximal end (not shown)
of the pusher element 90 in the operating field can become the
second point of electrical contact 133 with the energy source.
Otherwise the use and effect is similar to FIG. 11B. This system
could use a single-electrode introducer catheter such as shown in
FIG. 14B, although used differently than depicted there because the
second electrode would be connected to the contact 133 of the
pusher element 90 instead of to the skin.
[0148] FIGS. 12A-H describe various types of introducer catheters
200 containing two electrodes that have novel functionality with
regard to electrolytic detachment of embolic agents. Conventional
electrolytic detachment mechanisms do not incorporate electrolytic
or detachment-related functions into the introducer catheter, which
limits the function of the detachment mechanism. For example, the
ability to combine controlled detachability with an
operator-determined variable length embolic agent is limited. The
use of wires 220 and contacts 221 in the introducer catheter 200
will provide functionality that is not possible with conventional
systems that incorporate the conductive elements on the body of the
embolic agent or its detachably attached pusher element, said
conventional systems not having the versatility of this novel
disclosed system to use embolic agents that may undergo detachment
at a single chosen point from amongst a plurality of possible
points along its length, thus enabling the use of very lengthy
embolic agents that are disclosed herein and in keeping with the
spirit of this invention including the treatment of large abnormal
cavities. FIG. 12I describes an introducer catheter 200 also having
anode and cathode both incorporated into the catheter body, however
not intended for electrolytic detachment, and instead with both
electrodes making direct contact with electrical contacts on other
elements related to detachment mechanisms that involve
electrification.
[0149] FIG. 12A with cross section views FIGS. 12A-1 and 12A-2 show
an introducer catheter 200 with a hub 201 on its proximal end 206,
a middle 207, a distal end 210, a wall 208 and lumen 209, and is
flexible, yet remains pushable as described elsewhere herein for
all other introducer catheters 200. It may have more complex
architecture to provide ideal physical properties in keeping with
conventional systems. Novel elements include electrically
conductive wires 220 that are exposed to the environment at the hub
201 where they may be connected to external wires 174 that connect
to a source of DC current 176 such as a battery. The electrically
conductive wire 220 on the left passes, insulated, through the
dielectric wall 208 of the catheter to its distal end 210 where it
then comes in contact with the lumen 209 at a point called the
electrical contact 221, where it will contact the corresponding
contact point of an embolic agent as seen in later figures. The
contact 221 may be composed of a noble non-corrodible metal so that
it does not diminish during electrolysis, thereby maintaining full
contact until detachment has occurred at the designated detachment
point. The opposite pole of the power source 176 connects the
second electrically conductive wire 175 to the electrically
conductive wire 220 on the right, of opposite polarity 231, which
then passes insulated in the wall 208 of the introducer catheter
200 to reach the second electrical contact 221 of opposite polarity
231 at the distal end 210, which is not directly in contact with
the bulk of the lumen 209 or the contact of the embolic agent (not
shown). Instead, it contacts the ionic fluid such as blood or
saline solution (not shown) in the lumen recess 223 in which ionic
fluid or blood will be present. This will support electrolytic
corrosion of the corrodible portion of the embolic agent as
depicted in many forms in this invention. The embolic agent (not
shown) has an outer diameter very slightly smaller than the inner
diameter of the introducer catheter 200 so cannot directly contact
the recessed contact 221 of opposite polarity 231 on the right,
preventing short circuit.
[0150] FIGS. 12B-E depict cross sections of variant introducer
catheters 200 that provide roughly similar function as described
for FIG. 12A. In each figure, the drawing on the left represents a
distal location 210 on the introducer catheter 200 and the figure
on the right represents a middle location 207. In FIG. 12B, the
distal end 210 of the introducer catheter 200 has a contact 221
that occupies a large portion of the lumen 209 within its wall 208
as shown, to provide extensive contact with the contact on the
embolic agent (not shown). As in FIG. 12A-1, the second contact 221
of opposite polarity 231 is recessed within the lumen recess 223
within its wall 208. As shown in the figure on the right, in the
middle portion 207 of the introducer catheter 200, the
corresponding wires 220 for each polarity are seen coursing
insulated within the wall 208. FIG. 12C is similar to 12B except
that multiple wires 220 are used for each polarity converging onto
their respective contacts 221. This may permit the use of smaller
sized wires 220 or the wires may be structured so as to also
provide stiffness and support properties to the introducer catheter
200 that are desired. In this example, the first 4 wires 220 in the
clockwise direction beginning with the 12 o'clock position service
the recessed contact 221 of opposite polarity 231 from the other
wires 220 which service the contact 221 on left. FIG. 12D shows a
variation whereby there are multiple contacts 221 in continuity
with the lumen 209, each with its own wire 220, and there are
multiple recessed contact 221 of opposite polarity 231 in lumen
recesses 223, each contact 221 also being connected to its own wire
220. FIG. 12E depicts a variation whereby there are multiple wires
220 per contact 221, and the contact 221 on the left is in contact
with a large portion of the lumen 209, while contact 221 of
opposite polarity 231 on the left is crescent shaped and recessed
in the lumen recess 223 with a portion of wall 208 in the middle
208 that prevents direct contact between electrified embolic agent
1 and contacts 221, which instead contact the ionic fluid or blood
bathing the area.
[0151] FIG. 12F with cross section FIGS. 12F-1 to 12F-3 are a
sequence view of a different embodiment of a two-electrode
introducer catheter 200 showing an example of the detachment
process. The introducer catheter 200 has, within its wall 208, a
wire 220 for one polarity and another wire 220 of opposite polarity
231 that end in respective contacts 221 near the tip 211 of the
catheter as shown. The contact 221 of first polarity 230 is
circumferential and protrudes very slightly into the lumen 209, to
increase surface contact with contact 36 on the embolic agent.
Therefore the second contact 221 of opposite polarity 231 is at a
different level within the catheter, closer to the tip 211 of the
introducer catheter 200, and is recessed within the circumferential
lumen recess 223 containing ionic fluid or blood. Said contact 221
may not directly contact the embolic agent but is in close
proximity. The embolic agent 1 is similar to that described in FIG.
6P except the distal marker 13 is located slightly more distally as
shown, is one of several novel types described herein that could be
used in this system. It has a monofilament 5, and an electrically
corrodible wire 6 which also forms a connector 35. The embolic
agent 1 has an outer diameter that is very slightly smaller than
the inner diameter of the introducer catheter 200. The power source
and external wires are not depicted because they are similar to
those depicted in FIG. 12A, where wires exit the proximal end 206
of the introducer catheter 200 to contact with wires 175 from the
power source 176. When DC power is applied, the circuit is as
follows: power source to wire 220 to contact 221 of first polarity
230 to contact on embolic agent 1 (non-corrodible metal) to
connector 35 (electrolytically corrodible metal), through ionic
solution to contact 221 of opposite polarity 231 to wire 220 of
opposite polarity 231 to power source. Electrolytic corrosion
occurs at the connector 35 which becomes the detachment point 28.
The distal fragment of embolic agent 1 remains in the target
tissues (not shown) and the other elements are removed. The
proximal fragment of embolic agent 1 may be used as a pusher to
push the last few millimeters of embolic agent 1 out of the
introducer catheter 200. Since the embolic agent has a series of
connectors 35, the operator may choose which site will become the
detachment point 28 without any modifications of the embolic agent
1 by simply positioning the chosen site at the level of the
contacts 221 in the introducer catheter 200.
[0152] FIG. 12G and FIGS. 12G-1 to 12G-3 depicts various views and
cross sections of a similar electrolytic introducer catheter 200
seen in FIG. 12F, but with minor modifications and using a smaller
diameter embolic agent 1 of a different type. The system is shown
after electrolytic corrosion of the embolic agent 1 at the
detachment point 28 has already occurred in the manner described in
this invention. The embolic agent 1 is an electrolytically
corrodible wire 6 with an insulating coating 31 over most of it,
except in the bare area 39 which is positioned to be in contact
with the proximal contact 221 and in close proximity to the distal
contact 221 of opposite polarity 231 in the lumen recess 223 of the
introducer catheter 200. The power source and external wires are
not depicted as they are similar to those shown in FIGS. 12A-F,
where electrical wires 220 exit the proximal end 206 of the
introducer catheter 200 to contact with wires 174 from the power
source 176.
[0153] FIG. 12H and cross section FIGS. 12H-1 and 12H-2 show an
embodiment of the introducer catheters 200 with both electrodes
incorporated, with one electrode making physical contact with the
embolic agent 1 and the other contacting the body fluids or ionic
flush solution. Introducer catheter 200 has two electrical wires
220 imbedded in its wall 208, insulated from the environment and
the lumen 209. One wire 220 ends in the proximal one of the two
contacts 221, and the contact 221 is concentric and protrudes
slightly into the lumen 209 to make contact with the corresponding
contact 221 on the embolic agent 1. The other wire 220 is of
opposite polarity 231, and is helically wound in the wall 208 of
the introducer catheter 200 to provide structural functions as well
as electrical. The other contact 221 of opposite polarity 231 is
located on the outside of the wall 208 of the introducer catheter
200 and will contact body fluids, tissues, or ionic flush solution.
The proximal ends of wires 220, which are not shown but are similar
to those depicted in FIG. 12A, exiting the introducer catheter 200
proximally and contacting the wires 220 of the power source 176 for
both electrodes. The embolic agent 1 in this example is described
in detail in FIG. 6S and has a contact 36 which contacts the
contact 221 on the introducer catheter 200, said contact 36 also
contacting the connector 35 which is electrolytically corrodible
and does not conduct to the embolic segment 52 distal to the
detachment site 28 at the bare area 39. When DC current is applied,
electrolysis will occur at the detachment point 28 of the embolic
agent 1 as described herein.
[0154] FIG. 12I and cross section FIGS. 12I-1 to 12I-3 depicts an
introducer catheter 200 with both electrodes in its structure, but
is not structured for electrolytic detachment and instead enables
other types of detachment by making direct physical and electrical
contact of both of its electrodes with corresponding contacts 221
on the embolic agent 1 or its related detachment 120 or pusher 90
elements (not shown). In this example, it is shown to be used to
facilitate the creation of heat in order to cause detachment 28
through melting of metal, solder, heat-sensitive glue, or heat
sensitive electrically conductive glue. The depicted introducer
catheter 200 has two wires 220 imbedded in its wall 208, one on the
left of opposite polarity 231 from the other on the right. Each
wire 220 exits the introducer catheter 200 and connects to a power
source as described for FIG. 12A and FIG. 12H. Both wires lead to
contacts 221 which protrude slightly into the lumen 209 and
physically contact the embolic agent 1 which is a wire 6 that is
composed of an electrically conductive metal with a relatively low
melting point that is above body temperature. When power is
applied, current will flow predominantly through the short segment
of metal in the wire 220 between the contacts 221 of the introducer
catheter 200 at the detachment point 28, resulting in detachment as
shown in the second drawing. The wire 6 in this area will have a
sufficient electrical resistance that results in generation of
adequate heat to quickly melt the metal. This embodiment may also
be used with the detachment system depicted in FIGS. 11B and
12J.
[0155] FIG. 12J shows two embodiments of embolic agents that may be
used with the introducer catheter 200 in FIG. 12I. The first two
drawings depict the same embolic agent 1, exploded on the left and
non-exploded in the middle view. The embolic agent 1 includes a
series of repeating segments 52, each with a proximal end 18 and a
distal end 19. Composition of the embolic agent 1 is a conducting
metal or metalloid. On the distal end 19 of each segment 52 is a
protuberance 279, shaped like a cone, which mates with a depression
280 in the proximal end 18 of the abutting segment 52 providing
electrical contact between the segments 52. On the flat portion of
the mating surfaces, heat sensitive glue 140 or solder is present,
which is preferably conductive but not necessarily so. In the
middle drawing, the embolic agent 1 is seen intact functioning
physically as a unit, and the locations of the contacts 221 and
wires 220 of the introducer catheter 200 are shown schematically.
When current is applied, it passes through the metal embolic agent
1 between the contacts 221. The composition of the embolic agent 1
in this location provides sufficient electrical resistance to
generate heat that melts the bond, allowing the segments 52 to
separate. The drawing on the right shows a variation where there is
a small gap between the segments 52 filled by a small amount of
solder or conductive glue 140 which will melt when current is
applied, resulting in separation of the segments 52.
[0156] FIGS. 13A-E depict electrolytic introducer catheters 200
that include one electrode within their structure. In some uses,
the embolic agent and related elements function as the other
electrode for completing the circuit. In other uses, the electrode
in the catheter may be used to provide current to an area of the
embolic agent or related detachment elements focally near the tip
of the catheter without electrifying a long segment of embolic
agent, thereby providing the novel functionalities of this
invention. In FIG. 13A and cross section FIGS. 13A-1 and 13A-2, one
electrode from a power source 176 connects to wire 174 at or near
the hub 201 of introducer catheter 200 which connects to the wire
220 helix imbedded in the wall 208 of the introducer catheter 200,
said wire 220 coming into contact with the contact 221 near the tip
211 of the introducer catheter 200, where the contact 221 ends in a
lumen recess 223 communicating with the lumen 209. There it is in
proximity with, but may never physically touch, the embolic agent 1
due to smaller diameter of recess 223. Although many different
embolic agents could be used with this introducer catheter 200, the
catheter in this embodiment is described in detail in FIG. 6K. The
operator positions the embolic agent 1 so that the bare area 39 is
near the tip 211 of the introducer catheter 200. The hub 201 of the
introducer catheter 200 is located extracorporeal of the patient
body while the tip 211 and a substantial portion of the embolic
agent 1 are located in or near the target tissues (not shown). The
second wire 175 from the power source 176 is connected to the bare
portion 39 on the proximal end 18 of the embolic agent 1. In this
example, there is another bare area 39 seen proximal to the hub 201
of the introducer catheter 200, however electrolysis will not occur
here because it is not in contact with body fluids or ionic flush
and is open to the air of the operating field. Therefore, the
conductive wire 6 of the embolic agent 1 will be of opposite
polarity 231 than for the introducer catheter 200. When current is
applied, electrolytic corrosion will occur at the bare area 39 near
the tip 211 of the introducer catheter 200, which is in the body
(not shown), and detachment will occur at the detachment point 28.
This variation of introducer catheter 200 permits the use of many
embolic agents 1 for some of the objectives of this invention, for
example enabling the use of a very long, operator-determined length
of embolic agent 1 with controlled detachment 28 near the tip 211
of the introducer catheter 200.
[0157] FIGS. 13B-C and cross section FIGS. 13B-1 to 13C-1 show
views of variations of electrolytic introducer catheters 200 that
include one electrode within its structure. The distal ends 210 of
the introducer catheters 200 are depicted. In FIG. 13B, the
electrical wire 220, as in FIG. 13A, is helically wound within the
wall 208 of the introducer catheter 200 and makes contact with
contact 221 at the tip 211 of the introducer catheter 200, which in
turn makes contact with the body fluids, tissue, and flush solution
inside the body (not shown). The embolic agent 1 in the lumen 209
of the introducer catheter 200 is similar to the one shown in FIG.
6W where it was described in more detail. Briefly, it has a
corrodible wire 33 with a coating 31 and is composed of segments 52
that are connected by connectors 35 which are composed of
dielectric material. As shown in FIG. 13A, it has a bare area in
the operating field extra-corporeally where the opposite pole of
the power source may be connected (not shown). When current is
applied to the wire near the hub of the introducer catheter (not
shown) and to the extracorporeal contact on the embolic agent (not
shown), the contact 221 of the introducer catheter 200 serves as an
electrode, and the bare area 39 of the embolic agent 1 wire 33 will
serve as the electrode of opposite polarity 231. Electrolysis will
result in corrosion and detachment at the detachment point 28 as
there are no other bare areas more proximally and current will not
flow more distally than the visualized connector 35 because it is a
dielectric 30. The position of the contact 221 could potentially
allow direct contact between the contact 221 and the distal portion
19 of embolic agent 1 that is already deployed into the target
tissues, which will often touch the tip 211 of the introducer
catheter 200. This could create a short circuit, so only embolic
agents which are insulated, non-conductive, or non-electrified
distally to the detachment point, such as the depicted embolic
agent 1, would be used with this variation. FIG. 13C shows a
variation of FIG. 13B where the contacts 221 of the introducer
catheter 200 are imbedded in the wall 208, with side holes 217
extending from the contact 221 to the outer surface 232 of the wall
208 of the introducer catheter 200. Other aspects of the
description of the introducer catheter 200 are the same as for FIG.
13B. The embolic agent 1 shown in this embodiment is the same as
the one described in detail in FIG. 6X, although many embolic
agents described herein would also work with this system. When the
power source wires (not shown) are connected to the introducer
catheter 200 and the embolic agent 1 extracorporeally, electrolysis
will occur with corrosion at the intra-corporeal bare area 39 of
the conducting corrodible wire 6 which is surrounded by insulating
coating 31 everywhere intra-corporeally except the bare area 39
which was created by the operator using detachment tools (not shown
and as described elsewhere in this disclosure) and will result in
detachment of the embolic agent 1 at detachment point 28. In this
example, the side holes 217 are too small to allow embolic agent 1
which is already coiled in the target tissues (not shown) around
the tip 211 of the introducer catheter 200 to touch the contact
221. Therefore, a short circuit will not occur even if there are
un-insulated conductive portions of embolic agent 1 distal to the
detachment point 28, which could be a consideration with other
embodiments of embolic agent.
[0158] FIG. 13D shows another variation where introducer catheter
elements and embolic agent elements serve as both electrodes for
electrolytic function. The introducer catheter 200 has one wire 6
serving one contact 221 near the tip 211, said contact recessed
away from the lumen 209 in a lumen recess 223, contacting the blood
or flush fluid (not shown) present in the lumen 209, which also
bathes the embolic agent 1 in this area. The embolic agent 1 is the
same as shown in FIG. 6I but is shown in its modified state,
whereby a short bare area 39 has been created by removing a short
segment of the coating 31 as described herein, causing the
detachment point 28 where electrolytic corrosion will occur once
power is supplied to the wire 220 of the introducer catheter 200 as
described in FIG. 13A, as well as to the wire 6 in the embolic
agent 1 at a bare portion in its proximal portion in the operating
field, (not shown) similar to as that described in FIG. 13A and
elsewhere herein.
[0159] FIG. 13E and cross sections FIGS. 13E-1 and 13E-2 depict an
embodiment of introducer catheter 200 similar to that shown in FIG.
13D, except with addition of electrically insulating one-way valves
203 which are used to create a small local environment within the
introducer catheter for electrolytic corrosion while dampening the
flow of current to surrounding fluids and tissues where secondary
corrosion of other bare areas of corrodible metal could otherwise
occur. Reference to FIG. 13D should suffice for explanation of
other elements of introducer catheter 200 of this variation in FIG.
13E. The embolic agent 1 is described in detail in FIG. 6F, and
includes a corrodible helical wire 33 with coating 31, with
uncoated bare areas 39 in multiple locations and radio-opaque
markers 13. The valve 203 is, in this embodiment, a conventional
semi-rigid non-porous elastic compound, such as latex or silicone
or other compound with similar characteristics, capable of
providing a substantially fluid-tight seal around the embolic agent
1 near the tip 211 of the introducer catheter 200, with said valve
203 located in a recess 223 in the internal wall 208. This valve
203 is a round leaflet shaped to permit flow from proximal to
distal but not in the opposite direction. It will permit the
passage of the embolic agent 1 in the usual manner. The valve 203
provides sufficient seal without overly obstructing longitudinal
motion of the embolic agent 1. There are two valves 203, one
proximal and one distal to the recessed contact 221 where
electrolysis may take place. The valves are sufficiently
electrically insulating to prevent substantial electrolytic effect
or corrosion of bare areas 39 of corrodible embolic agent 1 that
may exist in the proximal introducer catheter 200 or distal to the
tip 211 of the introducer catheter 200 in the target tissues (not
shown). This helps to direct electrolysis of the corrodible embolic
agent 1 to the desired site indicated for detachment point 28.
Effective isolation of the small volume of ionic flush solution
which is electrified for electrolysis may improve the results when
using very simple varieties such as uncoated corrodible wires or
those with multiple bare areas that are all electrified such as in
this example.
[0160] FIG. 13F depicts a section of a dual lumen introducer
catheter 200 allowing for insertion of a conductive wire 128, which
is a detachment element 120, into the additional lumen 218 similar
to the manner in which a guide wire or embolic agent 1 is inserted
in conventional catheters. The conductive wire 128 is connected to
the power source in the operating field (not shown), and the
conductive wire 6 of the embolic agent 1 in the lumen 209 is
connected to the opposite electrode as seen in FIG. 13A. The
embolic agent 1 was described in detail in FIG. 6J. It has tape 45
sealing the bare areas 39 as manufactured, and has been modified in
this example by the operator who has removed the tape in one area,
leaving a bare area 39 at the planned site of detachment 28. This
introducer catheter 200 has advantage of simplicity of design and
manufacture.
[0161] The series of embodiments in FIGS. 13A-F provide rapid
electrolytic detachment of embolic agent 1 using 1 electrode as an
integral part of the introducer catheter 200, or inserted into a
second lumen 218 of a modified catheter 200. Many different types
of the embolic agents which are not shown in FIGS. 13A-F but are
described in this invention are compatible with these systems and
can be used in variation. Other possible embodiments could include
different configurations of wires or contacts so long as the main
electrolytic process remains intact.
[0162] FIGS. 14A-B depict two variations of electrolytic detachment
systems that apply one electrode to the skin of the body 580 and
the other electrode to the conductive wire in the embolic agent 1.
FIG. 14A is a longitudinal section and with FIG. 14A-1 cross
section view of an introducer catheter 200 and embolic agent 1,
with a schematic drawing of power source 176 and skin pad 227. This
introducer catheter 200 does not have electrolytic components
integrated within it and is essentially a conventional introducer
catheter. The embolic agent 1 is described in detail in FIG. 6U.
Other embolic agents in this invention would work well with this
system as well. The wire 174 from the power source 176 is connected
to a conductive skin pad 227 which is applied to the skin on the
body 580. The second wire 175 of opposite polarity 231 from the
power source 176 is connected to the wire 6 of the embolic agent 1
at the proximal end 18 in the operating field as described herein.
The bare area 39 of the embolic agent 1 where there is no capsule
43 or coating is positioned at the tip 211 of the introducer
catheter 200 that is within the target tissues (not shown). Not
visualized here are bare areas beyond the tip 211 of the introducer
catheter 200, already deployed in the target tissues which will not
undergo electrolytic corrosion because the wire 6 in the embolic
agent 1 is not continuous from segment 52 to segment 52, and are
insulated by the dielectric capsule 43. This configuration of
electrolytic wiring and its use in combination with the novel
embolic agent 1 shown, as well as many other novel agents described
herein, provide novel functionality including the potential for use
with very long embolic agent 1 whose length is variable and
determined by the operator intra-procedurally with detachment at an
operator-determined location such as the tip 211 of the introducer
catheter 200.
[0163] FIG. 14B and cross section view FIG. 14B-1 show an
embodiment of electrolytic introducer catheter 200 with a different
type of electrical contacts 221, which are pliable and flexible and
have a bias towards the center of the lumen 209 which keeps them in
constant contact with the embolic agent 1 even if its diameter is
smaller than the lumen 209, or if its diameter shrinks due to
corrosion as could occur in the event of a corrodible contact 36 on
some variations of embolic agent 1. The contacts 221 are positioned
in a circumferential lumen recess 223 may be leaflet-like, as
depicted, or may be similar to very fine wire brushings. This
depiction includes the embolic agent 1 described in FIG. 6S, which
has non-corrodible contact 36 which also serves as a radio-opaque
marker 13, and the helical wire 33 is has a coating 31. The
connector 35 of the embolic agent 1 is corrodible and electrified
via the contacts 36 of the embolic agent 1. Current flows through
the wires 174 of the power source 176 to the introducer catheter
200 wires 220 which pass current to the contacts 221, passing
current to the contact 36 of the embolic agent 1, then to the
connector 35 which corrodes and detaches at the detachment point
28. The other electrode of the power source is connected by wire
175 to the skin pad 227 on the skin of the patient body 580. In
variation, a needle may be used instead of a skin pad 227. These
brushing type or leaflet type contacts 221 of the introducer
catheter 200 could be used in any of the variations of introducer
catheters 200 described in this invention that have contacts that
directly contact the embolic agents. In one embodiment, the lumen
recess 223 may not be circumferential, or may be unilateral, so
long as constant contact with embolic agent 1 is maintained.
[0164] FIGS. 15A-B are depictions of two embodiments of venting
catheters which may be helpful to prevent over-pressurization of an
aneurysm cavity (also referred to as a "sac") when inserting a
volume of material into it as occurs with this invention. If there
are no pathways for egress of blood from the sac during
embolization, pressure could build up unless venting occurs through
the catheter, thereby preventing complications such as rupture
during the procedure. The other benefit of the venting lumen is to
allow injection of fluids such as flush or contrast material, and
in some examples to allow passage of small transducer probes to
measure pressures directly in the cavity. FIG. 15A shows an
introducer catheter 200, which is a venting catheter because it has
an additional lumen 218 as well as the lumen 209 used for other
purposes described herein. Catheters with multiple lumens are
already conventionally available, and in this example we describe a
novel configuration and combination with other elements that are
well suited for the objectives of this invention. The additional
lumen 218 may be small because its purpose of venting fluid may
still be served, and its shape in cross section may be irregular as
shown in order to keep the outer diameter of the introducer
catheter 200 as small as possible. This lumen 218 communicates with
the side port 212, which will accept a syringe, tubing, or other
conventional elements. This example embodiment also shows a
pressure transducer 655 integrated within the introducer catheter
200 at its tip 211, to sense the pressure within the aneurysm 582
and provide feedback to prevent over-pressurization. The transducer
655 connects to a wire 220 in the wall 208 of the introducer
catheter 200 which exits near the hub 201 and will connect to a
monitor (not shown). FIG. 15B shows a variation whereby a
transducer 655 is not integrated into the catheter, but may be
inserted into the additional lumen 218 or removed at will. When
inserted, it may be near the tip 211 of the introducer catheter 200
to sense the pressure in the aneurysm 582. Alternatively, the hub
201 corresponding to the additional lumen 218 may be connected to
conventional tubing (not shown) which may be connected to an
extracorporeal pressure transducer 655, whereby pressures may be
measured in this other conventional manner. In this example
embodiment, the additional lumen 218 is round in cross section to
accommodate a transducer 655 on a wire 656, or conventional guide
wires or other conventional accessories which are typically round
in cross section. Also depicted are multiple side holes 217 in the
wall 208 opening the additional lumen 218 to the local environment,
in this case the aneurysm 582. These may help maintain
communication of the lumen with the local environment since
end-holes may sometimes occlude or become covered by tissue. As
depicted in FIGS. 15A-B, these venting catheters may be used on
combination with a second introducer catheter of smaller diameter
(not shown) that may be inserted co-axially through the main lumen
209. This could include micro-catheters, which a name often is
given to small diameter catheters that pass co-axially through
other catheters. Alternatively, minor conventional modification of
these venting catheters with a hemostatic valve (not shown) on the
hub 201 corresponding to the main lumen 209 could convert them to
an introducer sheath which could be used in a similar manner of
permitting co-axial introduction of an additional introducer
catheter (not shown).
[0165] FIG. 16A is an overhead view, with a side view of select
elements, of an embolic delivery system 324 that pushes the embolic
agent 1 using feeder rollers 325. The components of this system are
all derived from conventionally available mechanical parts, which
are arranged in the novel manner shown to provide the novel
functions described in this invention. The simple nature of this
figure will suffice to teach this system and method since the
individual components are well known in the art of non-medical
systems such as wire feeders and other automation devices. This
embolic delivery system 324 includes a drive pulley 331, a drive
shaft 332, a hand crank 335, a timing belt 328, a tensioner pulley
343, two timing pulleys 379, two feeder rollers 325, and pulley
shafts 336 for each pulley. The timing belt 328 has teeth that mesh
with corresponding teeth on the timing pulleys 379 to provide a
more precise synchronization between the 2 feeder rollers 325.
These components are affixed to a rigid housing 384 (depicted
partially on the side view only) to maintain their proper positions
and orientations. Other depicted components of the embolic delivery
system 324 include a mounting hole 382, and a shaft sleeve 383.
Also shown is an introducer catheter 200 and embolic agent 1, shown
being advanced into an aneurysm 582.
[0166] The operator (not shown) may manually turn the hand crank
335, which is rigidly and non-movably attached to the drive shaft
332, which is also rigidly and non-movably attached to the drive
pulley 331. The drive shaft 332 is attached to the housing (not
shown) to allow rotational motion without substantial motion in any
other dimension. Rotation of the hand crank 335 thus imparts
rotational motion to the drive pulley 331 as shown by the dashed
arrow, which then drives the timing belt 328 as shown by solid
arrows. The timing belt 328 then drives the timing pulleys 379 in
rotational motion (depicted by solid arrows). The timing pulleys
379 are rigidly and non-movably attached to their pulley shafts 336
and thus cause the pulley shafts 336 to rotate. They do not move in
any other dimension because they are mounted to the wall 372 of the
housing 384 as described above for the drive shaft 332. The feeder
rollers 325 are rigidly and non-movably attached to the pulley
shafts 336, so they will rotate along with the timing pulleys
379.
[0167] The feeder rollers 325 roughly resemble rigid discs of hard
plastic or metal, however the outer rims may be composed of a
softer material with a high coefficient of friction such as a
synthetic rubber or urethane to provide traction against the
embolic agent 1 which is sandwiched between the two of them. When
pressed against the embolic agent 1 in the manner shown, their
rotations will project the embolic agent 1 forward into the
introducer catheter 200 as indicated by the straight solid arrow.
Reversal of direction of drive shaft 332 rotation will cause the
opposite motion of the embolic agent 1, withdrawing it from the
introducer catheter 200.
[0168] The tensioner pulley 343 is also part of the drive train,
however it is mounted differently to the housing in order to serve
its functions of providing proper tension to the timing belt, as
well as to re-direct the course of the timing belt 328 to perform
needed functions such as to provide to more surface contact area of
the timing belt 328 with the timing pulley 379 seen on the right. A
shaft sleeve 383 is mounted slidably in the long mounting hole 382
in the housing (not shown), which in this example has a simple
rectangular shape. When conventional means of fastening the shaft
sleeve 383 to the housing (not shown) are freed, the shaft sleeve
383 may slide up or down within this mounting hole 382. When
conventional fastening means are tightened, rigidly securing the
shaft sleeve 383 to a specific location in the mounting hole 382,
then it may not move in any dimension relative to the housing. The
pulley shaft 336 may rotate freely within the shaft sleeve 383, but
not move in any other dimension once the shaft sleeve 383 is
rigidly secured within the mounting hole 382. The tensioner pulley
343 may be mounted on the pulley shaft 336 either rigidly and
non-movably, or in a manner that allows rotational or translational
motion on the pulley shaft 336, since tensioner pulley 343 is idle
and passive and need only rotate freely in a spatial position that
permits the application of appropriate tension on the timing belt
328 for smooth function and proper orientation.
[0169] An introducer catheter 200 is shown receiving the embolic
agent 1 from the feeders in this example. In one embodiment, the
embolic agent 1 could be fed directly into a specialized element
that subsequently leads it to an introducer catheter 200, or it
could be fed into a side port adaptor and/or introducer element
337, as described in FIGS. 16D-G before passing on to an introducer
catheter 200. Also in variation, the feeder rollers 325, and part
or all of the remaining elements of the embolic delivery system 324
in FIG. 16A could be enclosed in a housing that is fluid-tight and
capable of being continuously flushed with an irrigant fluid as
described elsewhere herein. In one embodiment, instead of the
operator's hand, a conventional power motor, such as a small
electrical motor, with gearing to produce desired rotational speed
could be used to power the embolic delivery system 324. In
variation, the tensioner pulley 343 mounting apparatus may be less
rigidly secured within the mounting hole 382 during use, utilizing
a spring mechanism or other conventional system that will provide
the appropriate tension to the timing belt 328. The two feeder
rollers 325 in FIG. 16A, and associated timing pulleys 379, are
depicted as having their pulley shafts 336 mounted to the housing
384 with a fixed distance between them. In a variation, at least
one of them would be slidably adjustable from side to side to give
control over the force with which they compress the embolic agent 1
to provide the optimize the task of pushing it as described herein.
A grooved variation of feeder roller 325 is seen in FIG. 16G.
[0170] FIG. 16B is a depiction of an embodiment of an embolic
delivery system 324 similar to FIG. 16A, but with an increase of
the surface contact between the embolic agent 1 and the elements
that push it, through the use of 2 additional continuous timing
belts which also function to frictionally push the embolic agent 1
and are called feeder belts 378. Many of its components are the
same as in FIG. 16A, so for brevity they are not described here
again. In this embodiment, there are six feeder pulleys 380 and two
timing pulleys 379, which are attached to shafts 336 and a housing
as described for the feeder rollers 325 and timing pulleys 379 in
FIG. 16A. A first and second feeder belt 378 pass around the feeder
pulleys 380 in each column. The feeder belts 378 are toothed on the
inside to mesh with the toothed pulleys, but not on the outside
where they interface with the embolic agent 1. As the bottom two
timing pulleys 379 and associated feeder pulleys 380 are driven by
the drive train as described in FIG. 16A, they in turn drive first
and second feeder belts 378, which cause rotation of each feeder
pulley 380. The outside of these first and second feeder belts 378
is a high friction material that contacts the embolic agent 1 over
substantial length, and its friction against the embolic agent 1 is
also aided by the tension of the feeder pulleys 380 at each point
of pairing of the columns, where tension may be adjusted to provide
optimum propulsion of the embolic agent 1 and smooth function of
the system. Embolic agent is shown being advanced into introducer
catheter 200.
[0171] All of the various embodiments described for FIG. 16A could
likewise be applied to those shown in FIG. 16B. Additional
embodiments for that shown in FIG. 16B could include alterations in
the outside surface of the first and second feeder belts 378. The
outside surface of these feeder belts 378 could have traction
elements of many different types as described elsewhere in this
invention, to provide traction against the embolic agent 1 that
they contact. Likewise, the embolic agent 1 could employ the proper
corresponding traction elements as described in this invention. The
feeder belt 378 could also have a groove running longitudinally
along the mid portion of its outer surface, somewhat like the
groove 387 described on the feeder roller 325 in FIG. 16G.
[0172] FIG. 16C describes another variation of embolic delivery
system 324 with a modification that may make it slightly simpler to
manufacture, as well as to reduce the critical distance between the
friction surface between embolic delivery system 324 elements and
the embolic agent 1, which will be called the free distance 386.
The free distance 386 is so named because the embolic agent 1 is
"free" from constraint within the feeder elements, or the
introducer catheter 200 or other component that receives the
embolic agent 1 from the embolic delivery system 324. The embolic
agent 1 within the free distance 386 is prone to buckling and
errant feeding elsewhere than the introducer catheter 200,
resulting in failure, particularly for the more flexible types of
embolic agent 1. Reduction of the free distance 386 will therefore
help prevent failures and allow use of more flexible embolic agents
1. In this figure, the free distance 386 is reduced by using very
small diameters of the feeder pulleys 380 on their pulley shafts
336 closest to the introducer catheter 200. This allows the
proximal end 206 of the introducer catheter 200, which in this
example is mildly flared to accept the embolic agent 1, to be very
close to the last point of contact with the feeder belt 378 that is
pushing it forward.
[0173] The two large feeder pulleys 380 are driven by a drive train
(not shown) and could be of the same conventional type as already
described in FIGS. 16A-B, where a drive pulley drives a timing belt
that drives the shaft that holds the two other elements so they
rotate in unison. The two feeder pulleys 380 in FIG. 16C will
rotate in the directions shown by the curved arrows, thus driving
their respective feeder belts 378, which pass around six small
feeder pulleys 380 that are mounted to the housing (not shown) by
their pulley shafts 336 so as to permit free rotation around their
longitudinal center-line without any other motion except possibly
for some minimal translational motion to permit adjustment of the
degree of pressure that they apply to each opposing shaft 333 and
thus to the embolic agent 1 between them. The feeder belts 378 are
toothed internally to mesh with the pulleys, but have a smooth
outer surface to then push the embolic agent 1 forward into the
introducer catheter 200 as shown by the straight arrow. As in other
variations, the system may be operated in reverse to retract the
embolic agent 1, and it may be powered manually or by a power
motor.
[0174] FIGS. 16D-G include schematic views showing different
embodiments of introducer elements 337 to facilitate the pushing of
the embolic agent 1 without buckling or mis-feeding in the free
distance 386. FIG. 16D shows a hub 354 of the introducer element
337 where the hub 354 is not flared or fashioned with any
specialized aspects; it is a simple tube shape with the thinnest
possible wall that provides adequate support. Hub 354 may be made
of metal or strong hard plastic to provide a thin wall. This may
allow a very low free distance 386. FIG. 16E shows a flared or
conical hub 354 that is round in cross section. It increases the
capture width of embolic agent 1 as described above, but also
increases free distance 386. FIG. 16F includes a side view as well
as an overhead view showing a more complex hub 354 which includes 2
hoods 446 that extend over the flat planar surfaces of the feeder
rollers 325 but do not touch them. These serve to permit both
desirable functions of low free distance 386 since the non-hooded
portions are narrow and can fit between the upper portions of the
feeder rollers 325, and to also help to re-direct embolic agent 1
that has strayed out of the plane parallel to the flat plane of the
feeder rollers 325. FIG. 16G shows a grooved feeding roller 325
depicting the groove 387 where the embolic agent 1 could be
running. This serves to increase the surface area contact between
the feeder roller 325 and the embolic agent 1, to provide better
traction, and also to maintain the position of the embolic agent in
the precisely desired spatial location in order to facilitate the
pushing of it into the receiving lumen of the introducer element
with less risk of it buckling or mis-feeding due to angulation of
its trajectory. Integration of feeding elements of the embolic
delivery system and introducer elements 337 with other elements in
the chain of delivery of embolic agent to tissue are further
outlined in FIGS. 27A-B.
[0175] FIG. 17 depicts another novel embolic delivery system 324
for introduction of a wide variety of embolic agents 1 described
herein. Some of the prominent features of this system include a
long surface area of contact between the driving elements of the
embolic delivery system 324 and the embolic agent 1 enabling
substantial friction between them to facilitate the purpose, as
well as a continually constraining channel for the passage of the
embolic agent 1 through the embolic delivery system 324 to prevent
buckling or kinking of the embolic agent 1 at any point before it
is deployed within the target tissues beyond the tip of the
introducer catheter (not shown).
[0176] The depicted embolic delivery system 324 includes a housing
384 composed of a rigid wall 372 containing a hollow lumen 371 with
a complex architecture as shown. The lumen 371 is continuous
throughout the system such that a fluid injected at inlet port 345
would eventually flow out of the outlet port 346, and could bathe
the components at any location in the lumen 371. The wall 372 could
be any rigid material, most likely plastic or polymer. In this
housing are mounted other components that drive the embolic agent 1
upward as indicated by dashed arrow. These include a feeder belt
378 and feeder pulleys 380. Also present, outside the housing 384,
are connected drive train components including timing pulleys 379,
tensioner pulley 343, timing belt 328, pulley shafts 336, drive
pulley 331, and drive shaft 332. These drive and feeder elements
are conventionally available. The drive shaft 332 is rotated by an
external force, which could be manually driven, such as via a hand
crank or motor driven as described herein, using conventional
mechanical linkages and gearing as needed. The drive pulley 331 is
fixed rigidly to the drive shaft 332, thus rotating with the drive
shaft 332, and causing the timing belt 328 to move as shown. The
timing belt 328 drives the timing pulleys 379 as shown, with said
pulleys rigidly fixed to the pulley shafts 336 which are also
rigidly fixed to the feeder pulleys 380, which are thus also driven
as shown in the top drawing. The pulley shafts 336 of the timing
pulleys 379 pass through substantially water-tight holes in the
housing 384 to connect to and drive the internal feeder pulleys
380. The drive shaft 332 and pulley shaft 336 of the tensioner
pulley 343 do not need to fully penetrate the wall 372 of the
housing 384. The tensioner pulley 343 serves to route the timing
belt 328 as desired and to maintain proper tension on the timing
belt 328. The feeder pulleys 380 then drive the feeder belt 378,
which is pressed against the embolic agent 1 by the array of
smaller feeder pulleys 380, and feeds it in the direction as
indicated by dashed arrow.
[0177] This described embolic delivery system 324 may be connected
to an introducer catheter (not shown) directly or indirectly using
means described elsewhere herein, with transfer of embolic agent
from depicted embolic delivery system 324 to remaining portions of
invention as depicted elsewhere herein. The introducer catheter or
intermediate element may be attached to the outlet port 346 using
conventional attachment means. The embolic agent 1 enters the
embolic delivery system 324 through the inlet port 345, where a
side port adaptor (not shown) could also be used to allow passage
of embolic agent 1 as well as infusion of flush solution. In one
embodiment, the device may be more open, such that the wall 372
does not enclose the lumen 371. In this system, fluid flush would
not be circulated in the depicted system, although it would usually
be used for the side port adaptors and introducer catheters as
described elsewhere herein. In another embodiment, many elements of
the drive train that are herein depicted outside of the housing 384
could be located inside the housing, with protrusion of only the
drive shaft.
[0178] FIGS. 18A-H depict different embodiments of traction
elements 270 that may be applied along the inside and/or outside
walls of embolic agents 1 or modified pusher elements 90, differing
from conventional pusher elements as described herein. These
traction elements 270 will provide extra friction or mechanical
traction when desired for the movement of the embolic agent 1 in
the desired direction by another element such as a feeder roller in
an embolic delivery system or a pusher element 90. In brief
summation, conventional pusher elements typically push an embolic
agent through an introducer catheter whose lumen diameter is very
similar to the outer diameters of the embolic agent and pusher
element, like one piston pushing another through a tube. The
devices depicted in FIGS. 18A-F depict novel attributes termed
herein as traction elements 270 which may provide at least two
novel functions, including the ability to effect a net forward
advancement of the embolic agent 1 by imparting a to-and-fro motion
on the pusher element 90 (i.e., conversion of bidirectional motion
of the pusher element 90 into unidirectional motion of the embolic
agent 1 due to a directional bias of the traction elements) and the
retraction of the embolic agent 1 effected by retraction of the
pusher element 90 without a rigid attachment between the two
elements. The quality of directional bias is present in many but
not all of the traction elements 270 described herein. Even when
partial motion of the embolic agent 1 in the undesired direction
occurs, the overall net effect will be of forward motion of embolic
agent 1 despite to-and-fro motion of the pusher element 90. In
other contemplated embodiments, the pusher element 90 and embolic
agent 1 are actually mechanically locked together when constrained
within the introducer catheter 200 however using a different
mechanism than as previously described for FIGS. 1D-1L and 8A-11C.
Another function of the traction elements 270 in some variations
may be to simply increase traction between pusher element 90 and
embolic agent 1 in systems where they exist side-by-side within the
introducer catheter 200 instead of simply end-to-end as described
in FIG. 1D.
[0179] FIGS. 18A-F depict various embolic agents 1, most with
traction elements 270 as shown. Depicted embolic agents 1 are
flexible, composed of polymer, but could be composed of any
predominantly non-metallic flexible substance such as those listed
elsewhere herein. A pusher element 90 of appropriate length and
diameter that would be inserted into the lumen of the embolic agent
1 would encounter the traction elements 270, causing traction
between the two components so that movement of one component may
move the other. Such traction may be preferentially unidirectional,
or bidirectional, depending on the nature of the traction elements
270 as described in more detail below. Uni-directional traction
could have the effect of net forward motion of the embolic agent 1
despite the pusher element 90 having a back-and-forth motion. FIG.
18A depicts an embolic agent 1, hollow, round in cross section,
with a lumen 7, a wall 2, and with a full wall 2 thickness
longitudinal slit 17 running the entire length of the embolic agent
1. It has smooth inner and outer surfaces with a proximal end 17, a
middle 20, and a distal end 19. FIG. 18B depicts the embolic agent
1, opened up along the longitudinal slit 17 to expose the inner
surface, which can be seen to be smooth. Such a splaying open
defies the memory of the embolic agent 1, which would appear as
FIG. 18A in its resting state, however is opened in FIG. 18B for
purposes of description. Traction element 270 in the form of an
adhesive compound 50 is applied to the surface. This compound could
be of many types of glues or cements, but would preferably be
biocompatible, not having harmful effects if small amounts remained
on the embolic agent 1 after deployment, and also would provide
only a weak bond that is sufficient to provide the necessary
traction, but weak enough to permit easy separation of the embolic
agent 1 from the pusher element 90 when desired. This would allow
for bidirectional traction. Similarly, FIGS. 18C-F are similar
views of similar embolic agents 1 except with traction elements 270
integrated along their internal surface. FIG. 18C depicts traction
elements 270 of roughness 271 distributed along the entire inner
surface. This roughness could result from scoring of the surface
with a sharp blade, or special cutting tool that produces a scoring
pattern, or from molding of the surface during manufacture.
Chemical treatment could also potentially result in a rough
texture. Such roughness may cause increased traction in a
bidirectional manner upon motion of an appropriate pusher element
90, such as one with smooth outer surface as seen in FIG. 18I. If
the pusher element 90 had directional traction elements 270 on its
outer surface as described below for FIG. 18M, the traction of the
two components when used together could now be preferentially
unidirectional.
[0180] FIG. 18D depicts an embolic agent 1 with traction elements
270 composed of small ridges 272. These mildly elevated ridges 272
are shown circumferentially around the inner surface, although in
variation they could be less than circumferential. They are shown
as symmetrical along their long axis, so as to provide
bi-directional traction when used in conjunction with a
non-directional pusher element 90 such as that seen in FIG. 18I.
Preferentially unidirectional traction could occur if used with a
pusher element 90 with unidirectional traction elements 270 such as
depicted in FIG. 18M. In a variation, these ridges 272 may be
asymmetrical along the long axis of the embolic agent 1 so as to
provide unidirectional traction even when used with a bidirectional
pusher element 90 such as in FIG. 18I. Ridges 272 may be formed by
the cutting away of material around them during manufacture, or by
the building up of the ridges by application of material that is
welded or cemented to the surface.
[0181] FIG. 18E depicts an embolic agent 1 with traction elements
270 in the form of barbs 273 directed downward, applied to the
inner surface. Barbs 273 may be applied to the surface with cement,
or created by extraction of material from the wall of the catheter
around them. They provide preferential unidirectional traction when
used with any type of pusher element 90. FIG. 18F depicts an
embolic agent 1 with the traction elements 270 scales 274, similar
to fish scales, directed downward on the surface. These will also
exert preferentially unilateral traction. FIG. 18G-H are
contemplated embodiments showing variation of scales 274, with a
circumferential scale 274 pattern around the lumen 7 in FIG. 18G,
and non-circumferential scales 274 around the lumen 7 in FIG.
18H.
[0182] FIGS. 18I-M depict variations of surface properties and
traction elements 270 on the surfaces of various examples of pusher
elements 90. FIG. 18I depicts a smooth surface on a standard pusher
element 90 with added traction elements 270 of adhesive 50. It has
a proximal end 91, a middle 93, and a distal end 92. FIGS. 18J-M
depict pusher elements 90 with added traction elements 270, and a
transition 95 between surface with transition elements 270 and
surface with no traction elements 270. The traction elements
include roughness 271 in FIG. 18J, ridges 272 in FIG. 18K, barbs
273 in FIG. 18L, and scales 274 in FIG. 18M, where they are
depicted in two examples of configurations, including
circumferential and non-circumferential. The direction of the
directional traction elements 270 in FIGS. 18L-M are reversed from
the direction of the traction elements 270 on the embolic agents 1
in FIGS. 18E-H because the usual intention in practice would be to
advance the embolic agent 1 upon advancement of the pusher element
90.
[0183] Any of the pusher elements 90 depicted in FIGS. 18I-M could
be used in combination with any of the embolic agents 1 in FIGS.
18A-18F, for different effects. Variations in the devices in FIGS.
18A-M could include many factors including longer or shorter
lengths than those shown (in practice the pusher elements 90 would
likely be considerably longer), absence of a transition 95 with
traction elements 270 along entire length, and other possible types
of irregularities or non-smooth textures to provide traction, both
in a uni-directional or bi-directional manner. Any of the
circumferential traction elements 270 could be non-circumferential.
The embolic agents 1 may not contain a longitudinal slit 17 or slit
17 may be incomplete or spiral in configuration. Instead of ridges
added to the surface, depressions in the surface could be cut away
to provide traction and a similar surface effect. In variations,
the described traction elements 270 may occupy only portions of the
inner surface. The traction elements 270 may also be applied to the
outer surface of the embolic agents 1, alone or in combination with
application to inner surface. The method of using embolic agents 1
or pusher elements 90 with traction elements is described in more
detail in discussion of embolic delivery systems.
[0184] FIGS. 19A-E show other types of traction elements 270, which
differ mainly from those in FIGS. 18A-18M in that the pusher
element 90 and embolic agent 1 are adjacent within the lumen 209 of
the introducer catheter 200 during the method of use to be
described. In these figures, the introducer catheter 200 is seen to
have a wall 208 and lumen 209 as in other depictions. In the lumen
209 are an embolic agent 1, and a pusher element 90, side by
side.
[0185] In FIG. 19A, a simple configuration is depicted where the
introducer catheter 200 and pusher element 90 are both round in
cross-section, as in usual conventional elements known commonly in
the art. This provides little traction between them since there is
little surface area contact, so movement of one of them may not
effect significant motion of the other. FIG. 19B depicts a
configuration for embolic agent 1 and pusher element 90 whereby
there is an increase in the surface area of contact between the two
elements, thus leading to more traction so that motion of the
pusher element 90 along its longitudinal axis is more likely to
result in similar motion of the embolic agent 1. FIGS. 19C, 19D,
and 19E show different configurations of traction elements to
increase friction between them while maintaining a round cross
sectional shape for the two of them together as shown. The traction
between the elements depends on frictional forces since the
depicted configurations do not lead to a mechanical locking
together of them with respect to motion along the longitudinal
axis. The traction elements do not need to deform to prevent
sliding of one element against the other while constrained within
the introducer 200. The function of the traction elements 270 seen
in FIGS. 19A-E can be many fold and will also be described in
descriptions of embolic delivery systems herein. One way to make
use of these elements could be for the operator to pinch the
embolic agent 1 and pusher element 90 together with his fingers
outside of the proximal hub of the introducer catheter 200, and
then advance them as a unit. This could be useful if the embolic
agent 1 were so flexible (to facilitate nesting within the target
tissues) that it is difficult to advance through the catheter
alone. Once the pusher element 90 reached the target tissues, the
embolic agent 1 could be held stationary while the pusher element
90 was withdrawn until the tip was near the proximal hub of the
introducer catheter 200, when the cycle could be repeated and the 2
elements could be pinched together and advanced as a unit again.
This could result in a rapid administration of a large amount, or
great length, of embolic agent 1 as the pusher element 90 could be
advanced and withdrawn repeatedly fairly rapidly since it may never
completely be retracted out of the catheter. This method could also
be automated, whereby a machine performs the same simple
manipulations just described for the operator's hands. This is
shown in more detail in discussion of an embolic delivery system
elsewhere herein.
[0186] FIGS. 20A-20H depict traction elements 270 having additional
mechanical locking functionality beyond simple friction. These
traction elements 270 prevent sliding of the embolic agent 1 along
the pusher element 90 while constrained within the catheter, unless
there is deformation of one of the elements. Thus prevention of
sliding is not due to friction alone as was described for FIGS.
19A-E. There configurations enable 1:1 forward (advancement) or
backward (retraction) motion of the embolic agent 1 by manipulation
of the pusher element 90 with little or no sliding between them,
however they do not permit unidirectional bias of motion, so a
bidirectional motion of the pusher element 90 cannot be used to
effect a net forward motion of the embolic agent 1, differing from
FIGS. 19A-E. FIG. 20A depicts a locking traction element 270. The
embolic agent 1 is engaged with the pusher element 90 when inside
the lumen of an introducer catheter 200 (not shown). Both embolic
agent 1 and pusher element 90 have traction elements 270 with
depressions 280 and protuberances 279 that mate together. Both
elements are roughly round in cross-section, whereas in FIG. 20B
the cross-sectional shape of the embolic agent 1 and pusher element
90 are both closed incomplete circles so that when mated, they are
together round in cross section, to better conform to the lumen 209
of the introducer catheter 200. In FIG. 20C, as the elements of
FIG. 20B are pushed out of the tip 211 of the introducer catheter
200, as indicated by the arrow, they are no longer constrained, and
may separate.
[0187] Two other types of locking mechanical traction element 270
configurations are depicted in FIGS. 20D-F and FIG. 20G-H. FIGS.
20D-E depict traction elements 270 comprised of pins 277 on the
pusher element 90 and holes 278 on the embolic agent 1 that fit
together when they are constrained together inside the catheter
lumen. FIGS. 20F-H depict an embolic agent 1 and pusher element 90
that have traction elements 270 comprised of depressions 280 and
protuberances 279 that mate as seen in FIG. 20G. In FIG. 20H, it
can be seen that the overall cross-sectional shape of the
conglomerate is roughly round, thus fitting into a round lumen of
an introducer catheter 200. These traction elements 270 may have
advantage in manufacturing, as the depressions 280 and
protuberances 279 could be created by a rotating round tool or file
that is applied to the embolic agent 1 and pusher element 90.
[0188] FIG. 21A disclose one embodiment where the pusher element 90
may be of a simpler manufacture than a similar variation shown in
FIG. 20D-E. In FIG. 21A, the embolic agent 1 has many traction
elements 270 in the form of pins 277 along the otherwise flat face
of its length in two columns as shown. As in FIG. 20D, embolic
agent 1 cross sectional shape is a closed incomplete circle (where
the pins 277 are not located). The pusher element 90, unlike FIG.
20D, does not have corresponding holes, and instead is a deformable
member with enough tensile strength to resist substantial
stretching or breaking when pulled with enough force to cause
motion of the embolic agent 1. It is also semi-rigid as in other
described pusher elements 90 described herein. Its traction with
the embolic agent 1 is derived from the tendency for the pins 277
of the embolic agent 1 to press into, and deform, the mating
surface of the pusher element 90 when both are constrained inside
the introducer catheter 200. The cross-sectional view on top right
depicts the embolic element 1 and the pusher elements 90 in their
natural state outside of an introducer catheter 200. Note that the
pusher element 90 in cross section is basically a rectangle with
rounded corners as shown, although in variation it may not have
rounded corners, or may be a closed incomplete circle as in FIG.
20D. FIG. 21A also shows the deformed configuration of the pusher
element 90 in the cross sectional view on the lower right, where it
is constrained inside the lumen 209 of the introducer catheter 200
with the embolic agent 1. The depressions 280 in the deformable
pusher element 90 caused by the pins 277 of the embolic agent 1
serve to provide traction between the embolic agent 1 and the
pusher element 90 so that pushing or pulling the pusher element 90
will cause corresponding motion of the embolic agent 1. In
variation, the pins 277 could be on the pusher element 90, while
the embolic agent 1 could be the deformable agent without pins 277
or corresponding holes. This may offer advantage in some situations
where it is more desirable for purposes of manufacture, or purposes
of functional properties, to make the embolic agent 1 more
deformable, and place the more rigid traction elements 270 such as
the pins 277 on the pusher element 90.
[0189] FIG. 21B is a longitudinal and cross sectional view of
another variation where the traction elements 270 consist of barbs
273 on the embolic agent 1, and the deformable pusher element 90
has traction against the embolic agent 1 when constrained in the
introducer catheter 200 as shown. They are shown being pushed or
pulled out of the lumen 209 of the introducer catheter 200. The
pusher element 90 could be composed of different materials,
including soft plastic or polymer, or a woven strip as will be
described FIG. 21C. In variation, the traction elements 270 could
be scales 274 or one of the many other traction elements 270
described herein. Also, the traction elements 270 could be on the
pusher element 90 instead of the embolic agent 1, and the
deformable agent would be the embolic agent 1.
[0190] FIG. 21C is a perspective view of a small magnified portion
of a woven strip serving as a pusher element 90 as seen more
grossly in FIG. 21A or FIG. 21B. The micro filaments 106 are woven,
as shown in FIG. 21C, into a strip that can be extremely long
(shown here truncated at the top and bottom). The longitudinal
fibers give the strip a high tensile strength, and the horizontal
weave gives it a definable shape, as well as providing a means for
traction elements 270 such as barbs 273 on the embolic agent 1 (not
shown) to catch on and provide traction, since they would typically
hook over these horizontal fibers because they would be oriented as
in FIG. 21B, and the strip would be moving along its longitudinal
axis as it is pulled or pushed. This pusher element 90 could be of
many different shapes in its cross section, from a simple round
shape, to a rounded rectangle, or other shape that suited the
purpose of the specific embolic delivery system 324 or introducer
catheter 200.
[0191] FIG. 21D depicts a system which provides traction of pusher
element 90 against embolic agent 1 while permitting a circular
cross-sectional shape of embolic agent 1 for ease of manufacture
and passage through conventional elements. Pusher element 90 and
introducer catheter 200 with an embolic agent 1 seen in perspective
view, embolic agent 1 and pusher element 90 outside of a catheter
and constrained within the lumen 209 of an introducer catheter 200,
which has a wall 208. In the depicted embodiment, the embolic agent
1 is a helical wire 33 with central wire 6 as described herein. The
pusher element 90 is a solid member composed of material, such as
solid polymer or woven substance, as depicted in FIG. 21C, which is
flexible to lateral bending, but has substantial tensile strength
like a typical household string. When constrained in the introducer
catheter 200, it deforms somewhat to increase surface contact area
with the embolic agent 1 and corresponding ridges 272 of the woven
wire, which are serving also as traction elements 270. Pushing or
pulling the pusher element 90 will therefore move the embolic agent
1 correspondingly. This type of system may be useful in a variation
of the embolic delivery system 324 such as seen in FIGS. 22B and
22G. It has the feature of stabilization of the embolic agent 1 to
lateral movement while in the embolic delivery system 324, because
the diameter of the embolic agent 1 is greater than the width of
the lumen 209 containing the pusher element 90, so the
non-compressible embolic agent 1 cannot pass into the smaller
portion of the lumen 209 once the pusher element 90 has been
stripped away, in a system similar to FIG. 22B or 22G where the
embolic agent 1 passes into a smaller lumen which is a circle in
cross-section and only slightly larger than the diameter of the
embolic agent 1.
[0192] FIG. 21E is a depiction of another variation of traction
elements 270 used with embolic agent 1 and pusher element 90, where
both are resistant to axial compression and therefore maintain
circular configuration in cross section even when pushed together
side-by-side as when constrained within the lumen 209 of an
introducer catheter 200 (seen in cross section view only) which has
a wall 208 that resists axial stretching or change in shape. Both
have scales 274, which are oriented in opposite directions as
shown, to provide traction. In variation, many other types of
traction elements 270, as described herein, may be used with
similar effect.
[0193] FIG. 21F depicts a manufacturing element 630 that may assist
in the manufacture of the type of embolic agent 1 shown in FIG.
21D. It consists of a very rigid press 631 through which the
embolic agent 1 and the pusher element 90 may be positioned as
shown. Embolic agent 1 has traction elements 270 consisting of
ridges 272. External force in direction indicated by large arrows
may be applied, which allows the press to be compacted via the
press joints 632 where the two components are slidably connected.
This results in compression of the pusher element 90 against the
embolic agent 1 with great force, causing them to bond together in
a detachable manner that permits their function as described in
this invention. If the mechanical attachment caused by the
impression and deformity of the deformable pusher element against
the ridges 272 on the embolic agent 1 did not provide sufficient
bonding force, then it could be aided with addition of a sticky
substance of adhesive so long as bonding was not so excessive as to
prohibit dissociation during usage.
[0194] FIGS. 22A-G depict a system and variations that have a novel
method of causing advancement of the embolic agent 1 by pulling a
very flexible pusher element 90 which is adjacent to the embolic
agent 1 and exerts force on it using traction elements 270, and
which is then stripped away from embolic agent 1 which continues to
be projected forward. These represent another novel system and
method for delivery of embolic agent 1 into abnormal tissues. FIG.
22A is an upper perspective view of examples of pusher element 90,
traction elements 270, and embolic agent 1. The traction elements
270 in this example are convex on embolic agent 1 and concave on
pusher element 90 versions of the same pattern, where the contour
is a series of repeating depressions 280 and protuberances 279 that
can nest together without increasing the overall diameter of the
larger member, in this case the embolic agent 1. The pusher element
90 is inserted into the concavity of the embolic agent 1, where it
nests, with traction elements 270 on both members engaged. When
nested, the overall configuration in cross-section is roughly
circular, as seen later in FIG. 22B. It is evident in FIG. 22B that
a pulling or pushing motion of the pusher element 90 would cause a
similar motion of the embolic agent 1, especially if they were both
in the restrictive lumen 371 of embolic delivery system 324. FIG.
22B depicts views of the embolic agent 1 and pusher element 90 and
traction elements 270 of FIG. 22A, shown being used with an embolic
delivery system 324. The embolic delivery system 324 has a lumen
371 allowing the passage of an embolic agent 1 from its proximal
end 385, through the middle 388, and exiting the distal end 389, as
shown by the arrow. The embolic delivery system 324 has a rigid
wall 372 for support and to contain fluids and provide a
fluid-tight seal where needed. The pusher element 90 is fed through
a bifurcation 375 of the lumen 371 and exits the embolic delivery
system 324 through a side port 347 as shown by the dotted arrow.
The embolic agent 1 enters the embolic delivery system 324 through
the inlet port 345 and exits through its distal end 389, where it
may then pass into introducer catheter (not shown) or other
intermediate elements as described herein. Many variations of
traction elements 270 are possible with similar effects. The
driving force for the advancement of the embolic agent 1 comes from
the pusher element 90, which may be pulled by the operator's hands,
or by more components of the embolic delivery system 324, as shown
in this depiction, where the pusher element 90 is being pulled by a
spool 364 with a hand crank 335, the latter two elements being
depicted in a drawing of different scale in FIG. 22C where the
spool 364 and hand crank 335 are shown in overhead and side views,
and the pusher element 90 is also seen rolled up on the spool 364.
In FIGS. 22B and 22C, the operator turns the hand crank 335, which
is attached to the spool 364, and thereby the spool turns, taking
up the pusher element 90, and thereby pulling it from the from
embolic delivery device 324, thereby causing the described motions
of the pusher element 90 and embolic agent 1. The spool 364 permits
rapid deployment, and containment of the length of used pusher
element 90, which, for treatment of a large abnormal cavity, could
possibly be several hundred feet in length. These bulky components
such as the spool 364 or operator's hands, providing the driving
force for the pusher element 90 would be outside of the body that
contains the abnormal cavity to be treated, while the distal end of
the introducer catheter (not shown) is inside the body. Thus the
small diameter elements are inside the body, while the larger
elements do not require insertion through body tissues. Once the
desired length of embolic agent 1 has been delivered, or
determined, methods for completion including severing of the
embolic agent 1, or placement of short segments, or pushing of the
last portion with a conventional pusher element 90 that is simply
pushed by the operators hand and thrusts the trailing end of the
embolic agent 1 forward, may be used, and these techniques are
described in more detail elsewhere herein for different embodiments
of the invention.
[0195] FIG. 22D depicts a minor variation where the side port 347
has an obtuse angle of departure from the embolic delivery system
324. This might serve to reduce friction and binding forces of the
pusher element 90 against the lumen 371 of the embolic delivery
system 324, facilitating the intended function of the system, and
reducing risk of breakage of the pusher element 90, and to enable a
reduction in rigidity or thickness of the proximal end 385 of the
embolic delivery system 324 since the force of retraction of the
pusher element 90 will not be directed proximally, which
potentially bend the embolic delivery system 324 if the elements
were not rigid enough to prevent it. The force required to pull the
pusher element 90 can be provided by similar means as in FIG. 22B.
The embodiments depicted in FIGS. 22A-G have another advantage of
permitting the pusher element 90 to be highly flexible, without
need for columnar strength, since it is being used as a pulling
agent. It will therefore need to have adequate flexibility to round
bends and tensile strength to withstand pulling forces.
[0196] FIG. 22E shows two variations of embolic delivery systems
324 to demonstrate possible differences in proportions of devices
described in FIGS. 22B, 22D, and 22G. In the example on bottom, the
distance from hub 354 to bifurcation 375 is quite short, so that
only the narrower diameter portion of the embolic delivery system
324 would be inserted into the body thereby reducing the diameter
of the opening to a minimum, and serving in a manner similar to an
introducer catheter as described herein. In the top example, the
distance from hub 354 to bifurcation 375 could be much longer, so
that traction on the embolic agent 1 occurs close to the distal end
389 of the embolic delivery system 324, ensuring forward motion of
even very flexible and soft embolic agents 1. Such an embodiment
might be used in conjunction with a small diameter introducer
catheter as described elsewhere, or may be used in a manner similar
to an introducer catheter, i.e. partially inserted into the
body
[0197] In a variation of the foregoing, it is easy to envision the
use of many different types of traction elements 270, embolic
agents 1, or pusher elements 90 than depicted, with similar effect.
By way of some examples, the embolic agent 1 and pusher element 90
may be shaped very differently; they could be square or rectangular
in cross section, and they could employ any type of traction
element described herein. They could use an adhesive bond or
electrostatic attraction instead of the other traction elements.
There could be very small microfilament ties or bands connecting
the two elements, possibly wrapping around the elements, said bands
being easily broken when they are pulled apart. There could be
stitching of very fine filament that is bound tightly to the pusher
element 90 being stripped away, but is loosely stitched around the
embolic agent 1 such that gentle traction when desired will unravel
the stitching and dis-associate the two elements, leaving the small
fibers attached to the pusher element 90 which is not implanted.
The embolic agent 1 could be nested inside the pusher element 90
instead of the opposite as depicted in FIG. 22A. Many other
variations are possible that would still be in keeping with the
novel aspects of this invention.
[0198] FIGS. 22F-G depict an embodiment as described and shown in
FIGS. 22A-E. FIG. 22F shows an embolic agent 1 that includes
traction elements 270 composed of ridges 272, which could also be
described as an alternating series of protuberances 279 and
depressions 280 in a pattern often seen in conventional helical
wires. The pusher element 90 is seen wrapped around the embolic
agent 1 with a longitudinal slit 96 that makes the cross-sectional
configuration an incomplete circle (also shown in FIG. 22G.) The
outside surface of the pusher element 90 is smooth, but the inner
surface has traction elements 270 corresponding to those of the
embolic agent 1 to allow a mating of the elements, and also
consisting of alternating series of protuberances 279 and
depressions 280. Also shown in FIG. 22F, the pusher element 90 is
seen being stripped away from the embolic agent 1 by a force
directed upward and to the right, depicted by the arrow. When this
leading edge of the pusher element 90 is pulled by the operator or
other means, it can forcibly unwrap from around the embolic agent 1
that it enveloped, and in doing so, the traction elements 270 will
exert an upward force on the embolic agent 1 so long as the embolic
agent 1 is forcibly maintained in the same orientation by an
external element such as the lumen 371 of the embolic delivery
system 324 seen in FIG. 22G.
[0199] In FIG. 22G, an embodiment of the embolic delivery system is
shown. Embolic delivery system 324 with a wall 372, lumens 371, a
bifurcation 375 of the lumens 371, a side port 347, and an inlet
port 345 is shown. The embolic agent 1 and pusher element 90 of
FIG. 22F are seen passing into the inlet port 345 of the embolic
delivery system 324, with the pusher element 90 enveloping the
embolic agent 1. In this example embodiment, the embolic agent 1 is
composed of a series of shorter segments 52 that have a proximal
end 18 that abuts the distal end 19 of the adjacent segment. Before
entering the embolic delivery system 324, these segments are
maintained in proper position by the continuous enveloping pusher
element 90. When these elements reach the bifurcation 375 of the
lumen 371 into two lumens 371, one of which continues straight on
and provides a channel for the movement of the embolic agent 1 to
the target tissues (not shown), and the other lumen 371 bifurcating
at an angle and providing passage for the pusher element 90. The
embolic agent 1 is maintained within the larger of the two lumens
371 because it is too large to fit into the smaller one, and
because its direction of motion in a straight line is maintained by
its inability to prolapse into the smaller lumen 371 during normal
forces of normal operation, while the pusher element 90 unwraps
from around the embolic agent 1, crumples due to its flexibility
and poorly formed shape when not containing the cylindrical embolic
agent 1, and is pulled by the operator or other instrument out
through the side port 347. The pusher element 90 is depicted as a
dashed line as it passes around the embolic agent 1 near the
bifurcation 375 to indicate that is it out of the plane of the
2-dimensional longitudinal section in this figure. The pusher
element 90 will provide an upward force on the embolic agent 1,
driving it forward. Each segment 52 of embolic agent 1 will push
the previous one forward, since they are all constrained in a lumen
371 that is only slightly larger than the diameter of the embolic
agent 1. The use of segmented embolic agent 1 is optional, and
instead a very long single element may be used as described
elsewhere herein. As depicted, this system performs the novel
function of administering numerous short or medium length embolic
agents 1 in rapid succession.
[0200] Different methods of manufacture of the pusher element 90
are possible. It could be injection molded, made of polymer, to its
desired shape. It could be made like a conventional smooth-walled
tube, and then the slit 96 added to the side, then the traction
elements 270 cut or heat-molded on. It could be made from a
heat-shrinkable tubing, possibly reinforced with longitudinal fiber
elements of high tensile strength, into which the embolic agent 1
is inserted, then heat applied, and the pusher element conforms to
the contour of the embolic agent 1 then the longitudinal slit 96
applied by a cut.
[0201] Many variations of the system in FIGS. 22F-G are possible.
Almost any type of traction element 270 could be used instead of
those depicted. The surfaces of the embolic agent 1 and pusher
element 90 could all be smooth, and the necessary traction supplied
by frictional forces, or the application of a small amount of weak
adhesive that can be overcome when necessary for the elements to
separate. Different shapes of embolic could be issued instead of
cylindrical; it could be dumbbell shaped, or of many different
types of shape.
[0202] FIG. 22H depicts another variation of embolic delivery
system 324 variation of the previous two figures, employing the use
of embolic agent 1 and pusher element 90 that employs traction
elements 270 in a manner that causes forward propulsion of the
embolic agent 1 by using pulling forces instead of simply pushing
forces, thus taking advantage of the advantages of the effects of
pulling flexible objects over pushing them. This is novel since
current mechanisms for advancing embolic agents in conventional
systems use pushing forces only. The embolic delivery system 324
includes a housing 384 with a wall 372 and a hollow lumen 371 that
is continuous throughout and allows passage of other elements as
well as infusion of fluids. It also has a side-port 347 for
conventional delivery of infusion fluids, an inlet port 345 for
entrance of the embolic agent 1, and an outlet port 346 for exit of
the embolic agent 1. It also has another inlet port 345 for
entrance of the pusher element 90, and another outlet port 346 for
the exit of the pusher element 90. Embolic agent 1 and pusher
element 90 are intended to usually travel in the direction shown by
the arrows, although retraction in the opposite direction may occur
sometimes for proper position of the embolic in the target tissues
(not shown). All of the inlet ports 345, and the outlet port 346
for the pusher element 90 include an O-ring 373 to allow adjustable
fluid-tight seal around the elements passing through them. The
outlet port 346 for the embolic agent 1 is a conventional rotating
male connector that may connect and lock to conventional female
connections widely used in the art, and which may be on the
proximal end of an introducer catheter (not shown) so that the
embolic agent 1 may be smoothly and easily transferred from the
depicted embolic delivery system 324 into the introducer catheter
or intermediate element that leads to introducer catheter that
carries the embolic agent 1 to the target tissues.
[0203] The embolic agent 1 may have traction elements 270 as shown,
in this example in the form of ridges 272, although many variations
are possible. The embolic agent in this example is a helical wire
33 with central wire 6 as described herein, and is flexible to
lateral bending but semi-rigid to axial compression. The pusher
element 90 shown does not have traction elements, and is instead
softer than the embolic agent 1 and will therefore conform to the
contour of the ridges 272 as shown in the figure, when the two
elements are pressed together by the constraints of the system, and
the pressure caused by the feeder pulleys 380. In other
embodiments, traction elements 270 may also be on the pusher
element 90, or may be only on the pusher element 90 and not on the
embolic agent 1. The feeder pulleys 380 rotate around the pulley
shafts 336 that are fixed to the wall 372 of the housing 384, so
their only allowed motion is rotational. They directly contact the
pusher element 90 and embolic agent 1 and are within the lumen 371
of the embolic delivery system 324. The feeder pulleys 380 squeeze
the embolic agent 1 and pusher element 90 together to increase the
friction and traction between them. In variation, more sets of
feeder pulleys 380 may be included for more areas of pressure. The
operator (not shown) may pull the pusher element 90 from its upper
aspect outside the confines of the embolic delivery system 324,
causing forward motion of the embolic agent 1 and pusher element 90
as shown by arrows. In another embodiment, the pusher element 90
may be a continuous loop, like a belt, so that it can be much
shorter perform the same function as depicted. This loop may be
manually pulled by the operator, or could be connected to a drive
system similar to that shown in FIG. 17. The drive system could be
outside of the housing 384 of the embolic delivery system 324. This
embodiment could also be considered a variation of FIG. 17 where
the pusher element 90 essentially becomes very similar to the
feeder belt 378 in FIG. 17, and the main difference between them is
the fewer drive elements inside the lumen 371 in FIG. 22H. To this
effect further variation could include bilateral and symmetric
pusher elements 90 and feeder pulleys 380 for the system of FIG.
22H. In other variation, the embolic agent 1 and pusher element 90
may be packaged together by manufacturer, similar to method seen in
FIG. 22B, FIG. 22D, and FIG. 22G, and enter together through the
main inlet port 345 instead of depicted example in FIG. 22H where
pusher element 90 enters separately via second inlet port 345.
Another variation could include a second or more set of feeder
pulleys 380, particularly near the bifurcation 375 to assist with
compression of embolic agent 1 against pusher element 90, and to
provide a smoother motion of moving elements.
[0204] FIGS. 23A-E depict an embodiment of embolic delivery system
324 that translates a to-and-fro or bidirectional linear motion of
the pusher element 90 into incremental linear forward motion of the
embolic agent 1. In brief summary of operation, an upward linear
motion of the linear trolley 410 effects a predominantly and
roughly similar linear motion of the cam 407 and cam block 408, but
also causes a very slight clockwise rotation of the cam 407 causing
it to tightly grasp the embolic agent 1 and pusher element 90
against the cam block 408, so that linear motion is also imparted
to the embolic agent 1 and pusher element 90 in unison. When the
direction of linear motion is reversed, the cam 407 rotates
counterclockwise slightly, releasing its grip on the embolic agent
1, so that the cam 407 and cam block 408 and connected elements may
slide predominantly linearly, without also pulling the embolic
agent 1, which may remain stationary at this time. The pusher
element 90, being attached to the linear trolley 410 will be
retracted. Thus the overall effect is to advance the embolic agent
1 incrementally with each cycle, while there is no net motion of
the pusher element 90 with each cycle. The distal end 92 of the
pusher element 90 is depicted close to the middle 207 of the
introducer catheter, however its position within the introducer
catheter 200 is manually adjustable by the operator and could be
variable as fits the needs of the situation.
[0205] FIG. 23A depicts the track portions 406 of a guider 338,
both to be described in detail below. It also depicts a magnified 3
dimensional perspective view of the embolic agent, which is very
similar to FIG. 18A. The embolic agent 1 has a wall 2 and a central
round lumen 7 similar to a conventional tube, however with a
longitudinal slit 17 of full wall 2 thickness, which in this
example extends all the way from the distal end 19 to the proximal
end 18. FIG. 23A and FIG. 23B both represent the beginning of the
motion cycle where all components are stationary for a point in
time as one cycle ends and another begins, and direction of linear
motion is reversed as described below. FIGS. 23B-E depict the
system sequentially during a complete cycle. In FIG. 23A, an
embolic delivery system 324 contains a guider 338, a rigid cam 407,
a rigid cam block 408, a simple guider 416 attached to the cam
block 408, and a rotary-to-linear motion apparatus which includes
several rigid components including a first linkage arm 341, and a
second linkage arm 393 shown in exploded fashion, a third linkage
arm 394, 4 rotational joints 342, and upper rotational joint 414 a
drive shaft 332, 4 tracks 406, and 7 track pins 409, and a simple
guider 416. One of the track pins 409, located on the cam 407, also
serves as the upper rotational joint 414 of the cam 407.
[0206] Function and further detail is now provided for FIGS. 23A-E.
The drive shaft 332 is rotated by a drive train that is not
pictured here but uses a conventional rotary system such as a
hand-crank or electric motor and gearing as needed. The rotating
drive shaft 332 is connected rigidly to the first linkage arm 341,
which is connected to the second linkage arm 393 by a rotating
joint 342 that allows only rotary motion, like a pivot point, as is
the case for all rotating joints 342 in this figure. The second
linkage arm 393 is connected to the linear trolley 410 by a
rotational joint 342. The linear trolley 410 is slidably connected
to two fixed, stationary tracks 406 via track pins 409 as shown and
detailed further in the cross section view. The track pins 409 are
rigidly connected to the linear trolley 410, which rests on the
tracks 406. The tracks are rigidly incorporated into the rigid
board 411 which serves as the stabilizing mount for several
elements including the tracks 406, guider 338, and side port
adaptor 530, none of which may move in any direction relative to
the board 411. The rigid board 411 is generally flat in this
depiction, however may have various contours as needed to mount
components in a conventional manner in order to achieve the effects
described herein. The board 411 may be composed of any rigid
material or rigid compound such as hard plastic. It serves an
important role in maintaining the proper alignment of various
components for their function as being described herein. Components
not directly connected to the board 411 may be permitted to move
more flexibly according to their specific characteristics, e.g. the
introducer catheter 200 which passes from the outside of the body
580 to the inside of the body 580.
[0207] The four track pins 409 and the linear trolley 410 may only
move in a purely linear fashion along the Y axis by sliding of the
track pins 409 in the cam block 408. The shape of the track pins
409 and cam block 408 do not permit detachment of the two elements
or substantial motion in the X or Z axes. Thus the rotary motion of
the drive shaft 332 is converted to linear motion of the linear
trolley 410 by the action of the first linkage arm 341 and second
linkage arm 393 as will be shown in FIGS. 23B-E. The pusher element
90 is detachably, rigidly connected to the linear trolley 410 by
passing through a hole oriented along the Y axis of the linear
trolley 410 as shown, with a set screw 412 that may be tightened to
secure the pusher element 90 rigidly, or loosened to allow it to
slide in the hole 413 in the linear trolley 410. In FIGS. 23A-E the
set screw 412 is always tight so the pusher element 90 is always
secured. The operator may choose to loosen it for various functions
not described in detail herein such as manual operation of the
pusher element 90 for many purposes commonly practiced in the art.
The linear trolley 410 and the cam 407 are connected by the third
linkage arm 394 by 2 rotating joints 342 so that the linear motion
may be substantially transferred to the cam 407 and connected
components including the cam block 408, and attached smaller
elements to be described. Of important note is that the linear
motion of the linear trolley 410 is not entirely transferred to the
cam 407 because the mounting system of the cam also permits
rotational motion of the cam 407 around the upper rotational joint
414 of the cam, which is also the track pin 409 for the cam, thus
keeping a purely linear motion of the center point of the track pin
409 and upper rotational joint 414 while allowing a swivel or
rotational motion of the cam 407 in addition to its linear motion.
The cam 407 is attached to its cam block 408 solely by this one
track pin 409 so that its rotation may occur. Notably, the
rotational motion of the cam is very minimal, perhaps only a few
degrees, because upon being rotated clockwise, the cam meets the
cam block 408 and the interposed embolic agent 1 containing the
pusher element 90, and may not rotate further because the cam block
408 is mounted to its cam block 408 by two track pins 409 and
therefore may only move linearly in the Y axis without substantial
rotation. Also important to this relationship is the connection
between the cam 407 and cam block 408 is solely at the upper
rotational joint 414, thus permitting rotation motion of the cam
but not the cam block. The rotational joint 342 of the cam that
connects to the third linkage arm 394 does not engage the track,
and may thus rotate around the axis of the upper rotational joint
414 along with the rest of the cam 407.
[0208] Prevention of substantial counterclockwise rotation of the
cam 407 during an upward linear motion of the system is effected by
2 mechanisms, with a third possible mechanism described but not
depicted. First, an imaginary dashed line 415 from the center of
the rotational joint 342 and upper rotational joint 414 of the cam
407 is slightly off the pure Y axis as shown. This creates a bias
towards clockwise rotation of the cam 407 upon upward thrust of the
third linkage arm 394. Second, the third linkage arm 394 is also
longitudinally oriented slightly off the Y-axis to create another
bias towards clockwise rotation of the cam 407 upon upward motion
of the third linkage arm 394. Third, a conventional detent
mechanism could be mounted on the cam 407 and cam block 408 or
other elements in many possible conventional ways to prevent
counterclockwise rotation of cam during upward linear motion of
other elements.
[0209] Upon downward motion of the linear elements, the reverse
rotational cam 407 motion will occur. The downward force upon the
rotational joint 342 of the cam will tend to pull the cam in a
counterclockwise direction until the described imaginary line 415
is roughly in-line with the long axis of the third linkage arm 394,
which is roughly oriented along the Y axis with slight bias as
described above. Again, the rotational motion of the cam is very
small, but is enough to release pressure between the cam 407 and
the cam block 408 and therefore free the embolic agent 1 and pusher
element 90 from their grasp. The points along the edge of the cam
407 facing the cam block 408 have an increasingly greater distance
from the center of rotation at the upper rotational joint 414 in
passing from inferior to superior aspect, in order to provide the
gripping function upon clockwise rotation. This gripping function
is enhanced by the cam's 407 shape because as commonly occurs with
conventional cam gripping mechanisms such as those used in rope
climbing gear or other mechanisms, the force in the opposite
downward linear direction applied by the embolic agent 1 and pusher
element 90 due to some inevitable resistance to being pushed
upward, against the gripping surfaces of the cam 407 and cam block
408 will serve to further force the cam's 407 clockwise rotation.
In this manner, the more resistance there is to pushing the embolic
agent 1, the greater will be the grasping force around the embolic
agent 1 to help increase the friction and push it in the desired
direction. Also to enhance this friction, the cam 407 and cam block
408 may be enhanced with material(s) with a high coefficient of
friction such as urethane, for example, along the surfaces that
come into contact with the embolic agent 1.
[0210] Now the aspects and motion of the embolic agent 1 and the
pusher element 90 are considered here. As described throughout this
invention, an object is to dispense a potentially large quantity of
the embolic agent 1 to a relatively large body cavity or target
tissue 589, passing it from its storage system, through the embolic
delivery system 324 and various associated components, and through
an introducer catheter 200 which itself passes from outside of the
body 580 to the target tissue inside the body 580. In FIG. 23A, the
storage of most of the proximal end 18 of the embolic agent 1 is
not depicted, and may be similar to one of the variations described
elsewhere herein. In this example, embolic agent 1 need not be
stored inside a tank or enclosed structure, as it is not
necessarily bathed in fluid while in its containment apparatus.
Storage in this example could be as simple as a conventional spool
or reel, or other method of preventing tangling and providing
delivery with low resistance. Storage of most of the proximal end
91 of the pusher element 90 is also not depicted. This would
usually be accomplished in a conventional manner used commonly in
the art, such as simply laying it out in the workspace, either in a
straight or curved path, or with one to three simple coilings
performed manually by the operator. The pusher element's 90 length
is not as variable or as great as the embolic agent 1 since it is
not continuously deployed into the target tissues 589 and is simply
a tool of delivery of the embolic agent 1. Therefore it is
manageable using commonly used means in the art.
[0211] The course of the embolic agent 1 is discussed now. It is
pulled into the embolic delivery system 324, first entering the
guider 338, whose role it is to prepare the proper position of the
embolic agent 1 for feeding into the mechanism of cam 407 and cam
block 408. It also serves to provide a novel function of
integrating the flexible hollow embolic agent 1 with the solid
semi-rigid pusher element 90 such that the pusher element 90 is
co-axially positioned within the embolic agent 1. Coaxial
positioning of pusher element 90 inside catheters (not embolic
agents) is conventional and conventionally accomplished by passing
one through the end of the other. However, this is not possible in
this invention due to the great length of the embolic agent 1, so
novel aspects include the entry of the pusher element 90 into the
longitudinal slit 17 of the embolic agent 1, as well as the novel
use of a hollow embolic agent 1, and the novel method of passing it
over the stiffer pusher element 90 using coaxial technique. Once
the embolic agent 1 exits the guider 338 with the pusher element 90
located coaxially inside of it, the embolic agent 1 and pusher
element 90 then pass through the simple guider 416 which is rigidly
attached to the cam block 408. The simple guider 416 serves to
position the embolic agent 1 and pusher element 90 for feeding in
between the cam 407 and cam block 408 as described in more detail
shortly. When pushed upwards by the cam 407 and cam block 408, the
embolic agent 1 and pusher element 90 then pass into the side-port
adaptor 530. Although the side port adaptor 530 is optional and
could be eliminated, and the elements fed directly into the
introducer catheter 200 instead, the side port adaptor 530 may
serve to standardize the system somewhat since different introducer
catheters 200 may be employed with one standard side port adaptor
530 that could be included with a kit. It also permits the
application of flushing fluids at this level, which could be
infused into the side port 535 using conventional methods described
elsewhere in this invention and standard in the art. Since its
lumen 541 becomes continuous with the lumen 209 of the introducer
catheter 200 when they are connected rigidly, the flushing fluids
may pass into the target tissue 589 in this manner. Once the
embolic agent 1 and contained pusher element 90 pass though the
side port adaptor 530 into the introducer catheter 200, and then
the embolic agent may continue on into the target tissues 589. The
pusher element 90 does not similarly accumulate in the target
tissue 589 due to the mechanisms described in detail herein, and
the farthest extent of its distal tip could be variable and
controlled by the operator who may determine what length of the
element will be distal to the tether point at the set screw 412.
The pusher element will usually not extend beyond the distal end
210 of the introducer catheter 200, or into the target tissue 589,
although this may be performed as deemed beneficial by the
operator.
[0212] Returning now to more details about the guider 338, it is
secured rigidly to the board 411 and does not move or have moving
parts. As depicted in FIG. 23A, the guider 338 has two inlet ports
345 and one outlet port 346 all of which are in communication with
a central hollow lumen 371. Guider 338 is novel in its design and
function, since the lumens 371 of the 2 inlet ports 345 join in a
manner that wraps the hollow embolic agent 1 around the pusher
element 90. The lumen 371 of the inlet port 345 receiving the
pusher element 90 is a conventional hole, round in cross section,
as in most conventional catheters and tubes. The lumen of the inlet
port 345 for the embolic agent 1 is shown in cross section in the
magnified drawing indicated by the dashed lines, and is roughly "C"
shaped, within the solid, rigid wall 372, causing similar shape for
the embolic agent 1. The cross sectional configuration of the inlet
port 345 of the guider 338 that accepts the embolic agent 1 is
therefore suited for receiving the embolic agent in manner whereby
the solid elements of the inlet port 345 are in maximum contact
with the inside and outside surfaces of the wall 2 of the embolic
agent 1. The C-shaped wall 2 (in cross section) of the embolic
agent 1 fits into the C-shaped lumen 371 of the guider 338. This
serves to precisely control the position and orientation of the
longitudinal slit 17 of the embolic agent 1 for optimum smooth
opening and wrapping around the pusher element 90 that occurs at
the bifurcation 375 region of the guider 338. Moving to the
cross-sectional drawing of the inlet port 345 for the embolic agent
1 corresponding to a location closer to the bifurcation 375 as
indicated by the dashed lines, the configuration has changed
somewhat as shown. There has been a transition from the above
description to a more open shaped lumen 371, more like a sideways
"U", and the cross-sectional diameter of the wall 372 has increased
slightly. This serves to correspondingly open the longitudinal slit
17 of the embolic agent 1 to prepare it for acceptance of the
pusher element 90 at the bifurcation 375. Referring now to the
third and upper cross-sectional drawing of the guider 338,
corresponding to the level of the outlet port 346 where the two
lumens 371 of the two inlet ports 345 are now joined into one lumen
371 containing the embolic agent 1 which is wrapped around the
pusher element 90. Now the lumen 371 of the guider 338 is seen to
be round and conventional in cross section.
[0213] The pusher element 90 in this depiction is a standard metal
wire type, flexible with substantial, providing the columnar
strength and resistance to buckling and kinking that facilitate the
pushing of itself and the embolic agent 1 forward through the
system elements into the target tissue 589, overcoming the
resistances along the way. It is well known in the art that a
highly flexible micro catheter, similar in many ways to the highly
flexible embolic agent 1 in this example, is more easily advanced
through catheters when a stiffer wire is positioned inside its
lumen. Such forward motion is enhanced further by the simultaneous
advancement of both elements, facilitating the advancement of the
embolic agent 1 which can be quite floppy and difficult to advance
alone.
[0214] Inevitably, there will be some undesired friction between
the embolic agent 1 and the pusher element 90 within its lumen 7
upon the downward linear motion of each cycle when such friction
could adversely cause a downward motion of the embolic agent 1. In
the depicted invention, this is prevented by stronger frictional
forces on the embolic agent 1 at several locations including the
body 580, against the internal walls 208 of the introducer catheter
200 and side port adaptor 530, against the O-ring 537 of the side
port adaptor 530 which may be adjusted accordingly, against the
internal walls 372 of the guider 338, and at the bifurcation 375 of
the guider 338 where a downward force upon the embolic agent 1
would not result in downward motion of the embolic agent 1 unless
it were strong enough to overcome the forces that would be required
to cause un-wrapping of the embolic agent 1 from the pusher element
90 and force it downwards through the guider 338. Prevention of
this unwanted motion could also be facilitated by the use of
materials and/or coatings of the surfaces of the inside wall 2 of
the embolic agent 1 and the pusher element 90 so that the
frictional forces between them are much less (when not gripped by
the cam mechanism) than the opposing forces described above. Thus
their synchronous motion would only occur when grasped together by
the cam mechanism as described herein. Further mechanisms for
prevention of this unwanted motion are further described in FIGS.
23 F-H.
[0215] In FIGS. 23B-E the system is depicted at four quarter phases
during its cycle. FIG. 23B depicts the phase of the cycle when the
linear motion elements are in their maximally retracted (downward)
position. At this point in time, linear motion is transitioning
from downward to upward in direction. The maximum retraction of the
third linkage arm 394 is associated with maximally counterclockwise
rotated cam 407 and absence of grasp of the embolic agent 1 and
pusher element 90 by cam 407 and cam block 408. The solid curved
arrow depicts the counterclockwise rotation of the drive shaft 332,
which is always in this direction.
[0216] Progressing to FIG. 23C, the first linkage arm 341 has been
rotated into a horizontal direction as shown, thus lifting and
partially rotating the second linkage arm 393, thus pushing the
linear trolley 410 upwards in a pure linear motion through half of
its course. This has also pushed the third linkage arm 394 upward,
which at first instant rotates the cam 407 slightly clockwise as
depicted by the solid curved arrow, and then to push it upward
linearly, bringing the cam block 408 upwards linearly with the cam
407. The pusher element 90 was pushed upward by virtue of its
attachment to the linear trolley 410, as well as due to the
gripping forces and motion of the cam mechanism, and its distal end
92 is depicted closer to the distal end 210 of the introducer
catheter 200. The embolic agent 1 was moved upwards by the gripping
forces and motion of the cam mechanism, as well as the frictional
forces against the pusher element 90, and is seen to be passing
further into the target tissue 589.
[0217] Progressing to FIG. 23D, the linear motion components are
now at their full upward extent, and the cam mechanism remains
closed, with the cam 407 gripped against the embolic agent 1 and
cam block 408. The pusher element 90 is maximally forward in the
introducer catheter 200 as seen by its distal end 92 being very
close to the distal end 210 of the introducer catheter 200. The
embolic agent 1 has been pushed maximally into the target cavity
589 until the cycle repeats.
[0218] Progressing to FIG. 23E, the first 341 and second 393
linkage arms are oriented as shown, and the linear motion is now
retracted halfway through its downward course. The downward forces
caused the cam 407 to rotate slightly counterclockwise as shown by
solid curved arrow, releasing its grip on the embolic agent 1 which
does not move substantially during this portion of the cycle when
the linear elements are moving downward. The pusher element 90 is
retracted due to its rigid attachment to the linear trolley 410,
but does not cause retraction of the embolic agent 1 for reasons
detailed herein. The cycle repeats when the elements reach the
position of FIG. 23B in another quarter of a cycle.
[0219] FIGS. 23F-H depict variations of the above, in part to
address the potential adverse backward slippage of the embolic
agent 1 during the portion of the cycle when the linear motion
elements are being retracted downward, as was described in FIG.
23A. A modification of the guider 338 may include the addition of a
constricting O-ring 537 that is similar to the O-ring 537 that is
part of a conventional side port adaptor 530. This is depicted in
FIG. 23F in crude form, and not depicted in more detail here
because it is well described elsewhere in this invention and is
commonly available and conventional in various forms currently.
FIG. 23F is a frontal view of the guider 338 with cross section
view of the portion designated by dashed line, depicting a possible
location of a constricting O-ring 537 which has the function of
constricting the device very slightly, increasing the frictional
forces against the embolic agent (not depicted here) as it moves
through. This O-ring 537 may be operator controlled for optimum
friction, and may be easily changed during the procedure as needed.
If there is back-slip of the embolic agent 1, the O-ring 537 may be
tightened until back-slip ceases, without excessive tightening that
could lead to difficulties with proper advancement of embolic agent
1 during portion of cycle when this is intended.
[0220] Another mechanism for prevention of back-sliding of embolic
agent 1 is depicted in FIGS. 23G-H, which depict some select
relevant elements from FIGS. 23A-E with new elements added to help
accomplish the said purpose. Many elements, including the pusher
element 90 of FIGS. 23A-E, are omitted from the drawing to help
show the new elements, however all elements of FIGS. 23A-E would be
present in this embodiment. The elements seen in FIGS. 23G-H that
were already described in FIGS. 23A-E include a board 411, a cam
407, a guider 338, an upper rotational joint 414 for the cam 407,
and an embolic agent 1. New elements include a cam arm 417 which is
a rigid, hard component rigidly attached to the cam 407, and whose
motions are purely determined by the motions of the cam 407, and a
wheel 418 which can rotate freely about its shaft 333, with said
shaft connected to the cam arm 417 as shown, allowing only
rotational motion of the wheel 418 relative to the cam arm 417.
Additional new elements include two spring mounts 419 which are
rigidly attached to the board 411, a first spring 421 and a second
spring 423 attached to their spring mounts 419, 4 simple guiders
416, a gripper 420, and a swing arm 422 attached to a rotational
joint 342, which is attached to the board 411.
[0221] The cam 407 and its upper rotational joint 414 and the
guider 338 are configured and attached to the board 411 as already
described in FIGS. 23A-E. In FIG. 23G, the system is shown during
its downward (Y axis) linear motion as described earlier, when it
is desirable for the embolic agent 1 to remain stationary and not
be dragged down (Y-axis) by the frictional forces of the pusher
element within it (not shown here). The cam has rotated counter
clockwise as previously described, and this has swung the cam arm
417 towards the swing arm 422, which is now engaged by the wheel
418 that rotates freely and passively on its shaft 333 which is
connected to the swing arm 422. This forces the rigid swing arm 422
to swing counter clockwise into the position shown, against the
opposing force of the first spring 421. This first spring 421 is a
tension spring, pulling the swing arm 422 rather than pushing on
it. The swing arm is shown pressed against the numerous simple
guiders 416, which are rigid structures in the shape of a torus in
this example although many different shapes or pluralities could
provide similar function. The simple guiders 416 are rigidly
attached to the board 411 and will not move. The swing arm 422 is
pushing the gripper 420, which is slidably mounted to the board 411
so that it may move sideways (in the X-axis) slightly. When pushed
by the swing arm 422 as shown, the center of the gripper 420 is
aligned eccentrically along the Y axis with the centers of the
simple guiders 416 so that there is compression of the embolic
agent 1 and increase in frictional force on the embolic agent 1
which passes through all of them. The embolic agent 1 is therefore
held in position during this portion of the cycle, so that
back-slippage is minimized while the pusher element is
retracted.
[0222] Of note in FIG. 23G is that the swing arm 422 is in a
directly vertical position, parallel to the linear motion along the
Y-axis of some elements such as the cam arm 417 and wheel 418. The
wheel 418 rolls along the surface of the swing arm 422 so that the
two may always be in contact despite their different motions in the
Y-axis. This will keep the swing arm 422 pressed against the simple
guiders 416 and gripper 420 as shown during this linear motion
cycle so long as the cam 407 and cam arm 417 are rotated in this
position.
[0223] Moving to FIG. 23H, the same elements are shown, and are
therefore not labeled again. However, they are in different
positions as shown, corresponding to the opposing phase of the
cycle when the linear elements, such as the cam 407 and cam arm
417, are moving upwards along the Y-axis. As reviewed previously,
this is when the pusher element and embolic agent 1 are being
advanced upward simultaneously as indicated by the nearby solid
arrow. In FIG. 23H, the cam 407 has rotated clockwise, swinging the
cam arm 417 as shown, permitting the swing arm 422 to be pulled to
the left by the first spring 421. The cam arm 417 has moved upward
with the cam 407 in the Y-axis, but the swing arm has not since it
is secured to the board by the rotational joint 342. The gripper
420 is no longer under the influence of the swing arm 422 and is
therefore pushed by the attached second spring 423 rightward
towards the spring mount 419. This second spring 423 is an
extension spring, meaning it pushes the gripper 420 rather than
pulling it. The gripper is mounted in such a manner, using a
conventional detention mechanism (not depicted), that it may not be
pushed any farther to the left than as depicted in the figure. As
shown, its center is now in alignment with the centers of the many
simple guiders, so that in this position, there is little if any
gripping force exerted on the embolic agent 1, which may therefore
freely move upwards as determined by the mechanisms described in
FIGS. 23A-E.
[0224] Another mechanism that could be employed to prevent
back-sliding of the embolic agent 1 during part of the cycle is
accomplished by the use of directional traction elements on the
pusher element 90, embolic agent 1, or both. These elements and
their functions are described in detail elsewhere in this
invention, and will therefore be mentioned only briefly here. The
traction elements may be configured in a manner that promotes low
friction when the pusher element 90 is retracted downward (Y-axis)
and it is desirable for the embolic agent 1 to remain stationary.
The traction elements would however increase friction between the
two elements when they are advanced upward together, so that motion
of the pusher element 90 results in upward motion of the embolic
agent 1. This mechanism may obviate the need for the variations
described in FIGS. 23F-H. Variations on the above may occur and
remain within the scope of the invention. The track mechanism may
be of any other conventional type including rollers, wheels, or use
of different track and track pin configurations that provide
similar purely linear motion of the linear trolley 410. Instead of
using a cam, a simpler lever or arm could be substituted, which
would press against the embolic agent 1 similarly, but would simply
have a different shape than the depicted cam.
[0225] FIG. 23I depicts one embodiment of the embolic delivery
system 324 shown in FIG. 23A-E. It performs essentially the same
functions, however uses a different mechanism from the cam and cam
block to provide unidirectional grip of the embolic delivery system
324, providing incremental forward motion of the embolic agent 1
when the system moves upward, while avoiding pulling the embolic
agent 1 downward when the system moves downward, in a manner that
employs a different method of automatic grasping during one
direction and automatic release of friction during other direction.
In FIG. 23I, automatic grasping of the embolic agent 1, which may
also contain a pusher element (not depicted) as in FIGS. 23A-E, is
achieved with one or more encircling structures, herein termed
gripping rings 424, which have a large enough hole to permit free
passage of the embolic agent 1 when oriented orthogonally to its
long axis. Each gripping ring 424 is rigidly integrated with a long
segment 425 that connects via a rotational joint 342 to a rigid
push-rod 426. The rotational joint allows rotational motion between
the long segment 425 of the gripping ring 424 and the push-rod 426,
with free motion intended to have low friction. There is a
detention element 427 that is rigidly attached to the push-rod 426
that prevents the long segment 425 from rotating any higher than
the "3 o'clock" position shown on the left. However, the long
segment 425 may rotate downward as shown on the right, prevented
from rotating further only by the effect of the embolic agent 1
occupying the hole of the gripping ring 424 and preventing further
rotation, since the push-rod 426 and embolic agent 1 are both
restrained from motion in the x axis by mechanisms already depicted
in FIGS. 23A-E to keep them oriented parallel to each other with
only linear motion in the Y-axis possible. The push-rod 426 is
attached to a linear track system (not depicted) similarly to that
for the cam block in FIGS. 23A-E.
[0226] On the left in FIG. 23I, the system is shown during the
phase where the push-rod is moving downward, as similar to the cam
in FIG. 23A-E, and as indicated by the solid arrow. There is no
substantial motion of the embolic agent 1, because there is enough
space within the hole of the gripping rings 424 to permit their
easy sliding motion over the embolic agent 1. This configuration is
also seen in the cross section drawing. The detention elements 427
prevent the gripping rings 424 from being pushed by frictional
forces from the embolic agent 1 into an angled orientation that
would result in gripping of the embolic agent 1. Moving to the
figure on the right of FIG. 23I, the phase is shown whereby the
push-rod 426 is being pushed upward linearly as shown by the solid
arrow. Frictional forces from the embolic agent 1 cause the
gripping rings 424 to assume the angles shown, in the absence of
detention elements 427 to prevent such direction of motion, and
resulting in a narrowing of the effective diameter of the gripping
rings 424 in the X-axis, in turn resulting in a gripping action
(high friction) against the embolic agent, which is further
enhanced by greater force of the push-rod 426. This results in an
upward motion of the embolic agent 1 as shown by the solid arrow.
Many of the elements of this system are not depicted, but are
similar to the elements of FIGS. 23A-E and are therefore not shown
again here for brevity, as they can be easily modified slightly
using conventional techniques standard in the art to assimilate the
novel elements and mechanism of FIG. 23I.
[0227] FIG. 24A introduces an embodiment of embolic delivery system
324 that has the novel capacity of rapid sequential delivery of
multiple embolic agents 1 of a more conventional length, that are
much shorter than most of the other embodiments described in this
invention, and which may have memory for a coiled or complex
configuration. The embolic delivery system 324 has a proximal
portion 385, a middle portion 388, and a distal end 389. It
includes a housing 384 with a wall 372, a hollow core 428, and a
cylinder hole 429, springs 421, ball bearings 430, a ball housing
431, and a piston 360 with a distal end 434. It also includes a
cylinder 361 which includes concavities running its length called
feeder chutes 348, and rounded concavities called ball concavities
432 that mate with a portion of the surfaces of the ball bearings
430. The location of entry of the piston 360 into the feeder chute
348 in the three O'clock position is called the inlet port 345. The
wall 372 of the embolic delivery system 324 is integrated with the
wall 505 of the embolic containment apparatus 500, which includes a
delivery channel 508. Other elements of this embolic delivery
system 324 pertaining to the drive apparatus for the piston 360,
and elements that accept the embolic agent 1 after it is advanced
beyond this embolic delivery system 324 will be described in more
detail in later figures. The housing 384 of the apparatus, and the
cylinder shaft 433 are mounted to the rigid board 411 that is
common to other elements in other figures described herein that
relate to this current invention in order to maintain constant
positioning of elements in relation to each other. The cylinder
shaft 433 are mounted to the board 411 using conventional pillow
mounts (not depicted) that permit free rotation of the shaft
433.
[0228] The embolic agent 1 is similar to that previously described
in FIG. 4C or FIG. 9D. In FIG. 24A, the embolic agent 1 is packaged
slidably inside an introducer sleeve 327, the combination being
called a cartridge 26. The embolic agent 1 may be of any
filamentous variety described in this invention, including the type
shown in FIG. 2M-O, or FIG. 2A-D as well as many other pushable
embolic agents lacking special detachment mechanisms. The embolic
agent 1 is straight when packaged inside the rigid or semi-rigid
introducer sleeve 327, but may assume a coiled or other variant
configuration when unconstrained. In FIG. 24A, the cartridges 26
are seen loosely contained and longitudinally oriented within the
walls of the embolic containment apparatus 500, and falling by
gravity (as shown) or by a spring loading mechanism (variation not
depicted) through the delivery channel 508 to the integrated
embolic delivery system 324, where one cartridge 26 at a time may
come to rest within the feeder chute 348 of the cylinder 361. The
ends of the feeder chutes 348 may have slight tapers (not shown)
beyond the ends of the cartridges 26 to prevent longitudinal
sliding of the cartridges 26 during piston 360 travel. In this
embodiment, there are 4 feeder chutes 348 equally spaced around the
cylinder 361 as shown. The cylinder 361 may be rotated about its
long axis within the cylinder hole 429, and each quarter turn will
place the next feeder chute 348 into position under the delivery
channel 508. The rotation may occur as the cylinder shaft 433 is
forcibly rotated clockwise by a drive mechanism (shown in later
figures). The cylinder shaft 433 is rigidly connected to the
cylinder 361. Although the drive mechanism (shown in FIG. 24G) may
perform precise quarter rotations of the cylinder 361, the
precision may be enhanced by the mechanism shown. In the middle
portion 388 of the embolic delivery system 324 there is a ball
housing 431 which contains in its hollow core 428, a spring 421 and
a ball bearing 430, best seen in the cross section view. The ball
bearing 430 may move up and down within the hollow core 428 of the
ball housing 431 where it and the spring 421 are contained. The
spring 421 is an extension spring, meaning it pushes on the ball
bearing 430 against the cylinder 361 as shown. The cylinder 361 has
four ball concavities 432 in its mid portion, equally spaced around
the cylinder 361 between the feeder chutes 348 as shown. Each ball
concavity 432 is a bowl-shaped depression which matches the outer
convex surface of the ball bearing 430 in contour. When the
cylinder 361 is positioned so that one of its four ball concavities
432 is under the ball bearing 430, the ball bearing 430 is pushed
by the spring 421 into the ball concavity 432 and locking the
cylinder 361 into the optimum position within housing 384 to line
up the delivery channel 508 with the feeder chute 348 for seamless
transfer of cartridge 26. Since the ball is spherical in shape, it
will help to maintain the cylinder 361 in the proper longitudinal
position as well as rotational position. In the depicted
embodiment, an identical mechanism is located 180 degrees across
the system, to further facilitate the said function by providing
opposing forces of similar magnitude, thus stabilizing the cylinder
361 within the housing 384 by substantially removing the burden on
the cylinder shaft 433 with regard to providing stabilizing
force.
[0229] The force of the spring 421 is not great enough to prevent
active rotation of the cylinder 361 once sufficient rotational
force is applied to the cylinder shaft 433 by the drive mechanism
(depicted in later figures). When rotational force is applied, it
may overcome the force of the spring 421 that is pushing the ball
bearing 430, which will roll or slide against the ball concavity
432 as it moves backwards against the force of the spring 421
within the ball housing 431. Once a 1/4 turn has been achieved, the
ball bearing 430 will once again lock into the next ball concavity
432 and maintain stability and precise positioning of cylinder 361
within housing 384.
[0230] In FIGS. 24A-F, the function of this system is further
described and depicted. FIG. 24A consists of a 3-dimensional
frontal perspective view with 2-dimensional cross section views at
levels as indicated by dashed lines. FIGS. 24B-F consists of a
2-dimensional side projection views with 2-dimensional cross
section views at levels as indicated by dashed lines. The drive
mechanism will be described in detail in FIG. 24G. FIG. 24A
corresponds to the beginning of the cycle. The cartridge 26
containing the embolic agent 1 inside an introducer sleeve 327 is
seen loaded in the feeder chute 348 at the 12 o'clock position,
with the other 3 feeder chutes 348 empty. In the next phase of the
cycle, in FIG. 24B, the piston 360 has been thrust forward through
the feeder chute 348 in the 3 o'clock position. The distal end 434
of the piston 360 has passed beyond the distal end 389 of the
embolic delivery system 324 and through the lumen 371 of the outlet
port 346, and may be capable of further excursion as will be
discussed later. The mechanism that keeps the piston precisely
aligned, and moves it forward, will be described later. In this
phase of the first cycle, the piston 360 has entered an empty
feeder chute 348 and therefore does not push anything. In the next
phase of the cycle, in FIG. 24C, the system is depicted after a 30
degree clockwise rotation of the cylinder 361. Prior to this
rotation of the cylinder 361, the piston 360 is situated outside of
the feeder chute 348 as shown. The cylinder 361 will always turn in
1/4 rotation increments, so this figure is showing it in mid phase
during active rotation of the cylinder 361 for purposes of
teaching. The feeder chute 348 containing the cartridge 26 bearing
the embolic agent 1 and the introducer sleeve 327 is now seen in
approximately the one o'clock position. The rotation of the
cylinder 361 has caused the ball concavity 432 to rotate away from
the ball bearing 430, pushing the ball bearing 430 backwards in the
ball housing 431. It may now roll or slide against the cylinder 361
surface, and over the next feeder chute 348 to come its way, since
the feeder chute 348 radius is small relative to that of the ball
bearing 430.
[0231] Moving to the next phase in the sequence, in FIG. 24D, the
system has come to rest momentarily now that a 1/4 turn relative to
FIG. 24A has been achieved. It has come to rest because the drive
mechanism (shown in FIG. 24G) that turns the cylinder shaft 433
performs quarter turns. The ball bearings 430 have settled into the
ball concavities 432 to maintain the precise position of cylinder
361. Progressing to the next phase, in FIG. 24E, the piston 360 has
been driven forward into the feeder chute 348 in the direction
towards the distal portion 389. Since a cartridge 26 containing
embolic agent 1 inside an introducer sleeve 327 was rotated
previously to the 3 o'clock position where the piston advances, the
piston 360 is seen pushing the embolic agent 1 forward in the
direction of the distal portion 389 of the embolic delivery system
324. At the moment of this depiction, the distal end 434 of the
piston 360 is at the distal end 389 of the embolic delivery system
324, and is pushing the proximal end 18 of the embolic agent 1,
which can be seen extending beyond the outlet port 346. Further
excursion is possible and would result in subsequent pushing of
proximal end 18 of the embolic agent 1 into a receiving catheter or
side-port adaptor (not shown) which will then feed it to the
introducer catheter (not shown) and finally into the body, as will
be discussed further later. The piston 360, whose diameter is
approximately similar to that of the embolic agent 1 and smaller
than the diameter of the introducer sleeve 327, is aligned
precisely by mechanisms depicted later, to enter the center of the
cartridge 26, in the hollow center of the introducer sleeve 327, to
push the embolic agent 1 forward. Thus the embolic agent 1 and the
piston 360 are both sliding inside the introducer sleeve 327, which
is kept in place by a detention mechanism at the end, which can be
of conventional type, and is not shown clearly in this figure, but
can be as simple as a narrowing at the distal end 389 of the system
that is large enough to allow passage of the embolic agent 1 but
not of the larger caliber introducer sleeve 327, which will
therefore remain substantially motionless in the feeder chute 348
during this phase.
[0232] Once the distal end 434 of the piston 360 has traveled its
course until it has pushed the embolic agent 1 completely out of
the embolic delivery system 324 and into the receiving elements
(not shown), then it may be withdrawn back to the position as shown
in the next drawing in the cycle shown in FIG. 24F. Upon its
withdrawal, the now empty introducer sleeve 327 may have a tendency
to stick to the piston 360 enough to be dislodged backwards. Such
motion of the introducer sleeve 327 could be prevented by a caliber
narrowing (not shown) at the proximal end of the embolic delivery
system 324 that, like the one at the distal end 389 already
described, is large enough to accept the piston 360 but not the
larger caliber introducer sleeve 327.
[0233] After the full withdrawal of the piston 360 to the position
depicted, the cylinder 361 has rotated another quarter turn so that
the empty introducer sleeve 327 that was previously in the three
o'clock position is now in the six o'clock position where the
housing 384 is incomplete and there is nothing to hold the
introducer sleeve 327 in the feeder chute 348, as seen in FIG. 24F.
It may drop out due to gravity, or it may be dislodged by a small
probe or conventional flat or sharp element (not shown) as it
rotates by. Also shown is the cartridge 26 containing an embolic
agent 1 inside an introducer sleeve 327 is now in the feeder chute
348 in the 3 o'clock position, having just rotated over from the
twelve O'clock position.
[0234] As all future cycles are repeated, the same actions of the
elements of the embolic delivery system 324 will occur with each
phase: First, the cylinder 361 will rotate a quarter turn,
resulting in a new cartridge 26 loading into the feeder chute 348
at the twelve O'clock position, a loaded cartridge 26 being
positioned at 3 o'clock, and an empty introducer sleeve 327 being
ejected at the six o'clock position. Second, once the cylinder 361
has come to rest during each phase, the piston 360 will push the
embolic agent 1 out of its introducer sleeve 327 and out of the
embolic delivery system 324, and then, third, the piston 360 will
retract. These actions described in this paragraph are represented
by a continuous cycling from FIG. 24F to FIG. 24E, to FIG. 24F to
FIG. 24 E, in ongoing fashion as required by the operator. With
each cycle, a new embolic agent 1 is delivered forward into the
introducer catheter or intermediate elements (not shown), and a new
loaded cartridge 26 comes into place for another delivery of
embolic agent 1.
[0235] As shown in FIG. 24A, a rigid board 411 serves as a
framework for attachment of all components that must be maintained
rigidly fixed in position relative to each other, including the
cylinder housing 384 and the cylinder shaft 433 mounts. These are
un-depicted conventional shaft mounts that allow rotation of the
shaft 433 without allowing other substantial motion of the shaft.
Also mounted rigidly to the board 411 is the linear track to be
described in FIG. 24G, which will maintain the proper relationship
between elements described in FIGS. 24A-F and other drive elements
in FIG. 24G.
[0236] These novel functions and elements are controlled by drive
mechanisms described in FIG. 24G. Importantly, all of the actions
described in FIGS. 24 A-F are very simply accomplished by two basic
linear hand motions of the operator 600. A forward linear hand
motion will advance the piston, thus delivering the embolic agent
1, and then without changing grip or hand position on the device, a
backwards linear hand motion will result in the withdrawal of the
piston, followed by rotation of the cylinder 361 and all other
functions described above in FIGS. 24 A-F, so that the system is
now in readiness for another cycle upon repeated linear motion of
her hand. The system will allow the operator 600 to have exquisite
control over the speed and force of advancement of the embolic
agent, which can be important for safe delivery. The tactile sense
of the resistance to advancement of the embolic agent 1 will be
preserved, as is often desired by experienced operators. Thus the
novel functions of automation and greatly enhanced expedience of
repeated embolic delivery may be accomplished while preserving
desirable control aspects in this novel invention.
[0237] In variation, the ball bearing 430 may be replaced with a
pin or cylinder with its long axis oriented along the long axis of
the cylinder 361, and likewise instead of a ball concavity 432, a
longer groove that mated with the pin or cylinder could be
utilized, and still be in keeping with the overall important and
novel features of the invention. In another variation, the feeding
mechanism of the embolic agents 1 from the embolic containment
apparatus 500 to the embolic delivery system 324 would not rely on
gravity, but instead could utilize a spring loaded system more
similar to that depicted in FIG. 25A or of other design with
similar function. Many other variations in specific element design
and configuration are possible that would still be in keeping with
the novel and important functional aspects of this invention as
outlined herein.
[0238] FIG. 24G depicts the driving mechanism of the embolic
delivery system 324 that was partially described in FIGS. 24A-F,
and includes a side view (top drawing), overhead view (middle
drawing), and frontal (cross sectional) view, with further
explanation of view indicated by the labeled coordinates. The
dashed lines indicate the locations where the views correspond to
each other. As described in detail previously, the main functions
of this sub-system are, in very simplified form, to push the
embolic agent through the embolic delivery system 324 and on to the
receiving elements beyond (not shown), as well as to cause quarter
rotation increments of the cylinder 361, in sequence and
repeatedly. The rigid, cylindrical piston 360 is attached rigidly
to the linear trolley 410 which may move only linearly and slidably
along a linear track 406, which is rigidly attached to a rigid
board 411 that provides a rigid framework for attachment of all
elements that need to be secured rigidly in position. The board 411
is depicted on the overhead view only for simplification. The track
406 is attached to the same board 411 as are the cylinder housing
384 and the mounts for the cylinder shaft 433 (see FIGS. 24A-F).
Other elements are attached to the board as described individually.
As depicted in FIG. 24G, the mechanism for slidability of the
linear trolley 410 on the track 406 is a simple sliding function,
aided by use of low friction surfaces and precision construction of
mating surfaces. However, in variation, this linear motion could be
enhanced by addition of conventional roller elements such as
bearings or wheels that are not depicted.
[0239] The hand 601 of the operator 600 may grasp the handle 447 to
move the linear trolley 410 along the linear track 406 in either
direction. "Forward" will refer to a leftward direction in the top
and side views, and "backward" will be the opposite, and this will
correspond to the same descriptions put forth in FIGS. 24A-F. In
another contemplated embodiment (not depicted), a conventional
automated system may perform the same function of to-and-fro linear
motion in a repeated manner, in lieu of the operator's hand 601,
and this system may be controllable by the operator 600 using
conventional control mechanisms. In FIG. 24G, a forward motion of
the linear trolley 410 will move the attached piston 360 forward.
The piston's 360 further functions of pushing the embolic agent
through the cylinder 361 were described previously and not repeated
in detail here. The piston distal end 434 is indicated, and in FIG.
24G is seen to be located immediately outside of the confines of
the cylinder 361. Any further forward motion of the piston 360
would place it in the feeder chute 348 of the cylinder 361 as
described previously. Any backward motion from this position will
simply move it farther away from the cylinder 361, but it will
remain aligned linearly along the axis of the cylinder 361 so that
subsequent re-advancement will again place it into the feeder chute
348 of the cylinder 361. Also shown on the top view of FIG. 24G are
the trolley end stops 435 on both ends of the linear track 406.
These are rigidly attached to the track 406 and define the limits
of travel of the linear 410 that cannot move beyond the edge of the
trolley end stops 435. Also shown on side and top views, and
incompletely on the frontal view, are the elements that facilitate
cylinder 361 rotation including the rack 438, pinion 439, pinion
shaft 333, reel 442, tether 436, tether guides 437, clutch 440,
clutch arm 441, spring 421, and spring mount 419. The pinion 439 is
attached rigidly to its shaft 333, which is also attached rigidly
to a reel 442 as shown. The shaft 333 is attached to the board 411
using conventional mount (not depicted) that allows conventional
rotation of the shaft, but allows no other motion of the shaft.
Therefore any force that causes rotation of the pinion 439 will
rotate the reel 442 in the same manner. Rotation of the pinion 439
is caused by the rack 438 which is rigidly attached to the linear
trolley 410, which slides linearly along the linear track 406, as
when the operator 600 moves the linear trolley 410. The tether 436
is attached to the reel 442 as shown, so that rotation of the reel
442 will shorten or lengthen the tether 436 depending on direction
of rotation. The tether 436 is a filament, of many possible
compounds that provide flexibility like a string or thin wire or
thin wire rope, and that is substantially resistant to longitudinal
stretching. The other end of the tether 436 is attached to the
clutch arm 441 so that tension on the tether will pull the clutch
arm 441 and cause rotation of the clutch 440 to which it is rigidly
attached. The clutch 440 is attached to the cylinder shaft 433 as
shown. The clutch 440 permits unidirectional rotation between its
outer member rigidly attached to the clutch arm 441 and its inner
member rigidly attached to the cylinder shaft 433. The details of
the workings of the clutch 440 are not depicted as it is a
conventional element well known in the art of automation machines.
It permits free clockwise (frontal view) rotation of the outer
member (and attached clutch arm 441) relative to inner, but locks
the inner and outer members rigidly upon counterclockwise rotation
of the clutch arm 441. Therefore, clockwise rotation of the clutch
arm 441 would cause no rotation of the cylinder shaft 433 or
cylinder 361, whereas counterclockwise rotation of the clutch arm
441 would cause similar rotation of cylinder shaft 433 and cylinder
361. This latter motion would correspond to the `clockwise`
rotation described during normal function of the cylinder 361 in
FIGS. 24A-F because the perspective is different in those figures.
Repeated oscillation of the clutch arm 441 between the approximate
seven thirty o'clock position seen in FIG. 24G and the four thirty
o'clock position results in incremental quarter rotations of the
cylinder 361 in the counterclockwise direction without any rotation
in the clockwise direction, which is the desired rotation sequence
described previously in FIGS. 24A-F. The currently described
elements in FIG. 24G provide this functionality, in addition to
others to be described. Also, depicted are three tether guides 437.
These are simple cylindrical rigid objects attached rigidly to the
board 411 and do not move. They have low friction surface,
permitting sliding of the tether 436 around it, and guiding the
course of the tether 436. They are oriented as shown, with two in
parallel and those two orthogonal to the third, to perform said
function. Of note, the tip of the clutch arm 441 where the tether
436 attaches will move somewhat up and down in the Z-axis as it
rotates about the cylinder shaft 433, and therefore these guides
will also permit the corresponding expected sliding motion of the
tether 436 to occur. In variation the depicted tether guides 437
may be replaced by a single ring.
[0240] Therefore, by way of summary, a backward motion of the
operator's hand 601 and linear trolley 410 from the position
depicted will cause similar backwards linear motion of the rack
438, which will cause rotation of the pinion, thus rotating the
reel clockwise as would be seen in side view. This will take up
(shorten) the tether 436, thus pulling tension on the clutch arm
441, which will pull it rightward of the depicted seven thirty
o'clock position (frontal view) towards its final location in the
four thirty o'clock position. The length of the rack 438,
circumferences of pinion 439 and reel 442, length of clutch arm 441
are all designed to result in one pass of the rack 438 over the
pinion 439 to result in quarter rotation of the cylinder 361. Once
the rack 438 has completely passed backwards over the pinion 439,
the pinion will stop moving, and the linear trolley 410 will reach
the trolley end stop 435. The same backward motion of operator's
hand 601 also results in linear backwards motion of the piston 360
as described in FIGS. 24A-F.
[0241] Forward motion of the linear trolley 410 from the final
position described immediately above will therefore result in the
opposite motion of the pinion 439, rotating it counterclockwise
(side view), and slackening the tether 436. The spring 421 is
attached on one of its ends to the spring mount 419 which is
rigidly attached to the board 411, and on its other end to the end
of the clutch arm 441. Since it is a tension spring, it will pull
the clutch arm 441 towards the spring mount 419. This may now occur
since the tether 436 has been slackened, so the clutch arm 441 will
rotate back to its seven thirty o'clock position as depicted, once
the rack 438 has passed over the pinion 439 to return to the
position depicted in FIG. 24G. Importantly, due to the function of
the clutch 440, the cylinder 361 did not move upon this last motion
of the clutch arm 441.
[0242] Further forward motion of the linear trolley 410 along the
track 406 will advance the piston 360 into the feeder chute 348 of
the cylinder 361 and perform the functions described in more detail
in FIGS. 24A-F that result in deployment of embolic agent.
Referring again to FIG. 24G, since the rack 438 and pinion 439 are
no longer engaged, there is no effect on cylinder 361 rotation
during this portion of the excursion. Upon full forward motion, the
linear trolley 410 is stopped by the trolley end stop 435, and
motion may now be reversed by the operator 600 to retract the
piston, until the rack 438 and pinion 439 engage again and the
cycle is repeated.
[0243] Thus described is an embolic delivery system 324 in FIGS. 24
A-G that performs the novel function of converting a simple
to-and-fro hand 601 motion into the many complex functions
described, which ultimately have the novel effect of very rapidly
and repeatedly delivering embolic agents 1 to a body cavity via an
introducer catheter, allowing rapid delivery of a great many
embolic agents to treat sizable cavities in an expedient and
controlled manner, while maintaining the tactile sense of control
by the operator 600 during the delicate process of passing the
embolic agent 1 into the tissues without causing harm due to
excessive force or excessive bulk of embolic agent. Once the set-up
is accomplished, the to-and-fro hand 601 motions are all that are
required to repeatedly deliver embolic agent, as opposed to the
current standard practice that involves many steps by the operator
600 in loading individual embolic agents and pushing them through
the catheters. Although not outlined in detail herein, this
standard process has numerous steps and takes longer per each
embolic delivery by a very large factor, such that the described
invention could shorten a prolonged procedure by an hour or even
more in some situations, and make a procedure which is currently
impractical become practical, thus expanding the possibilities of
what diseases may be treated with embolic technique.
[0244] FIG. 25A include views of an embolic delivery device 324
that can deliver multiple embolic agents 1 in rapid sequence,
without introducer sleeves. In this embodiment, the embolic agents
1 are composed of a helical wire 33 with end pieces 61 tethered to
a central wire 6, are substantially straight and cylindrical in
their resting state, so they do not need to be constrained inside
an introducer sleeve to be easily handled in a straight
configuration. The embolic agents 1 are stored in an embolic
containment apparatus 500 consisting of a wall 505, and a hollow
delivery channel 508 where the embolic agents 1 reside and pass
towards the feeder chute 348 of the embolic delivery device 324.
The embolic agents 1 feed to the feeder chute 348 by an extension
spring 507 in the embolic containment apparatus 500 which presses
down on a plate 509 as shown, said plate 509 being slidably mounted
within the delivery channel 508 so that it may incrementally move
towards the feeder chute 348 of the embolic delivery system 324. In
the second drawing of the sequence, a substantially cylindrical
piston 360 of the embolic delivery system 324 is moved forward by a
mechanical linkage (not depicted here) or by the operator's hand
motions, to push the embolic agent 1 within the feeder chute 348
forward, to a connection between the embolic delivery system 324
and introducer catheter 200 (not shown) or intermediate elements as
described in this invention. Once the piston 360 is withdrawn to
its original position as seen in the third drawing of the sequence,
another embolic agent 1 is allowed to fill the now empty space in
the feeder chute 348, and the cycle may be repeated. Also shown is
a movable retainer 376, which is a long, narrow rigid plate. It is
shown in the top drawing positioned over the embolic agent 1 in the
feeder chute 348. It functions to more precisely align the embolic
agent 1 in the feeder chute 348 for smooth forward motion beyond
the feeder chute 348, and to maintain the semi-rigid or flexible
embolic agent 1 in a very straight configuration within the feeder
chute 348 so that forward motion of the piston 360 translates well
as forward motion of the embolic agent 1. In the second drawing in
the sequence, the movable retainer 376 is in same position as the
piston 360 has been advanced forward, pushing embolic agent 1. In
the third drawing, the movable retainer 376 has retracted outwards
through the opening 377 in the wall 372 of the embolic delivery
system 324 just above the feeder chute 348. This allows the next
embolic agent 1 to drop into the feeder chute 348 as shown, ready
for the next cycle to be repeated. The mechanical driver for the
motion of the movable retainer 376 is not depicted in this simple
figure, but may use conventional motion systems widely known in the
art, and importantly, may be linked with the motion of the piston
360 so that withdrawing the piston also results in the outward
motion of the movable retainer 376 without the need for additional
manipulations by the operator.
[0245] It is well known in the art that conventional wire-coil type
embolic agents do not always serve well in pushing other similar
embolic agents through a catheter. I.e., they are usually pushed
through one at a time by a pusher element until the embolic agent
is completely extruded from the introducer catheter. It is known
that attempts to push them in series may result in jamming within
the catheter when the proximal portion of one agent overlaps with
the distal end of the other. However in FIG. 25A, each embolic
agent 1 serves to push the former one through the introducer
catheter. They must therefore be designed to accomplish this task
without failing as described, i.e., the ends must not overlap, and
a smooth flow of agents must occur. To this end, such a device will
require embolic agents as described elsewhere herein with features
to permit serial delivery. In this embodiment, the end pieces 61
are disc shaped instead of the conventional rounded configuration
as seen in FIG. 9D. Many different types of embolic agent 1 may be
used with this embolic delivery system 324. They may have
microfibers attached to promote thrombogenicity. They may be
composed of polymer, or be similar to shown in FIGS. 3A-B where
agents particularly suited for serial delivery are shown.
[0246] FIG. 25B is a variation of the embodiment shown in FIG. 25A
that adds functionality of detachability and added control. The
major difference being the use of embolic agent 1 that has traction
elements 270 consisting of bidirectional locking elements 122 as
described elsewhere herein. Otherwise there are no substantial
differences in the embolic delivery system 1 or embolic containment
apparatus 500 from FIG. 25A. In FIG. 25B, when the embolic agent 1
falls or is pushed into the feeder chute 348, its bidirectional
locking element 122 automatically engages with the bidirectional
locking element 122 of the embolic agent 1 preceding it. The
bidirectional locking element 122 on the distal end 19 of the
embolic agent 1 is oriented as a mirror image with the
bidirectional locking element 122 on the proximal end 18, so they
engage as shown. In order to orient them for proper matching,
rotation of the embolic agents 1 around their long axes is
prevented while they are still within the embolic delivery system
324, as indicated by the rotational arrow stricken with an "X".
This is accomplished in this example by altering the
cross-sectional shape of the embolic agent 1 as shown, where it is
not completely round, but instead has partially straight sides as
seen best in the magnified image denoted by the dashed lines. The
walls 505 of the delivery channel 508 and the feeder chute 348 are
narrow enough to prevent rotation of the embolic agents 1 along
their long axes, so they will maintain the same orientation that
was given to them at the time of manufacture when they were loaded
into the embolic containment apparatus 500. Once they are attached
together, the embolic agents 1 will function as described in FIG.
8B permitting functions of detachability at the tip of the
introducer catheter (not shown here), and ability of operator to
advance or retract the series of attached embolic agents 1 by
manipulation of the proximal embolic agents 1 in the operating
field. By disconnecting the embolic delivery system 324 from the
introducer catheter (not shown), manual control of the proximal
embolic agents 1 may be achieved. They may be retracted, or
manually advanced using a conventional pusher element (not shown)
in a conventional manner.
[0247] FIG. 25C is a sequential set of two dimensional longitudinal
sections, with cross sections in three locations designated by the
lines corresponding to the top drawing. It depicts an embolic
delivery system 324 that delivers, in a rapidly repeating manner,
numerous separate embolic agents 1 that may be relatively short in
total length, and that may be straight when inside an introducer
catheter 200 or introducer sleeve 327, and may assume any of the
shapes described elsewhere herein when in their free state or when
unconstrained in the target tissues 589 in the body 580. A major
difference with FIGS. 25A-B is that it can work with embolic agents
1 within introducer sleeves 327 as a loaded cartridge 26, which may
facilitate serial delivery of embolic agents 1 with memory for
shapes other than linear, such as loops or coils, since they will
be constrained within their introducer sleeves 327 or introducer
catheter 200 or other elements described in this invention which
maintain embolic agents 1 in straight configurations until deployed
into the target tissues 589. Beginning from the top drawing, the
embolic containment apparatus 500 has a wall 505 that houses
numerous embolic agents 1, each of which is contained in its own
introducer sleeve 327, the assembled combination being called a
cartridge 26. The walls 505 form a delivery channel 508 that the
embolic agents 1 travel down incrementally towards the feeder chute
348 of the embolic delivery system 324. The cartridges 26 are
stacked in the embolic containment apparatus 500 and delivered to
the feeder chute 348 by mechanisms not depicted here, but were
represented in FIGS. 25A-B. In FIG. 25C, in the top drawing, the
system has not yet commenced its action. A cartridge 26 is situated
in the feeder chute 348, and the piston 360 is partially retracted.
An introducer catheter 200 is attached to the embolic delivery
system 324 at its outlet port 346, and the tip of the introducer
catheter 211 is in the target tissues 589. The piston 360 is
capable of only linear motion using conventional mechanical
linkages not shown here.
[0248] Progressing to the second drawing in FIG. 25C, the piston
360 has moved linearly forward, entering the introducer sleeve 327
which is too small to be pushed forward. The piston 360 is very
slightly greater in diameter than the embolic agent 1, and
approximately the same as the inner diameter of the hollow
introducer sleeve 327. Therefore, the described action pushes the
embolic agent 1 through the feeder chute 348 into the introducer
catheter 200 as shown. In this drawing, several cycles of action
have already been performed and the embolic agents 1, in series,
have begun to deploy into the target tissues 589 as shown. In the
third drawing of FIG. 25C, the piston 360 has partially retracted,
pulling the introducer sleeve 327 backward out of the feeder chute
348 due to friction between the piston 360 and the introducer
sleeve 327. The feeder chute 348 received a new loaded cartridge
26. In the fourth drawing, the piston 360 has retracted further,
resulting in the introducer sleeve 327 shearing off of the piston
360 due to the small hole 445 in the housing 384 whose diameter is
less than that of the outer diameter of the introducer sleeve 327.
The used introducer sleeve 327 falls away into a receptacle (not
shown) or the environment as waste. The cycle may be repeated,
resulting in more embolic agents 1 deployed in target tissues 589.
When the desired endpoint of embolization has been achieved, any
residual embolic agent 1 still remaining in the introducer catheter
200 may simply be removed by withdrawing the catheter with the
embolic agents 1 still inside, or by the passage of a long pusher
element (not shown) through the entire introducer catheter 200 to
push all embolic agents 1 still contained within it, into the
tissues beyond its tip 211. Any embolic agents 1 that can't or
shouldn't be passed may then be withdrawn with the introducer
catheter 200, which may be detached from the embolic delivery
system 324. If the introducer catheter 200 is a microcatheter which
is co-axially passed through a larger introducer catheter as
commonly practiced in the art, then catheter access to the target
tissues 589 is not lost even upon withdrawal of the introducer
catheter 200 and embolic agents 1 within.
[0249] FIGS. 26A-G depict several varieties of embolic detachment
tools 160 that may be used by the operator in this invention to
modify the embolic agent as needed intra-procedurally. FIG. 26A is
a perspective view which schematically depicts a wire-stripper 177
that may be applied to the embolic agent 1 as shown to mechanically
strip away a short segment of capsule 43, leaving a bare area 39 of
wire 6. It has a hinge 178 on one side to allow opening and
closing. FIG. 26B is a cut-away view showing the internal workings
of a wire stripper 177 which includes a sharp round blade 162 that
can open and close with the housing 179. FIG. 26C is a cut-away
view showing embolic detachment tool 160 with a sanding element 180
which is round in cross section, that may be squeezed around the
embolic agent 1 by the housing 179, and used to abrade the surface
of the embolic agent to remove capsule or coating from it. FIG. 26D
is a frontal view that depicts a heating element 181 within the
housing 179, which may be applied in contact with the embolic agent
to melt away material of low melting point, such as easily
removable seal as described in a variation of FIG. 6J. FIG. 26E is
a perspective view of a wire loop heater 182, which resembles a
conventional item in operating suites sometimes called cautery
pens. The wire 174 becomes hot and may be used to manually burn off
a small segment of capsule or coating from an embolic agent,
leaving the metallic components intact. FIG. 26F shows a tool with
electrodes 183 attached to a high voltage electrical power source
176, which may be pulsed, causing sparks to burn through the
dielectric coating or capsule of some embolic agents, creating an
exposed bare area of wire. FIG. 26G is a cut-away and frontal view
of a dissolution chamber 184. Its housing 179 has a hub 186 where a
syringe may attach to inject liquid into a fluid-tight chamber 184
formed by the housing 179 and two gaskets 185 which may open and
close with the housing 179 around the embolic agent. Filling of the
chamber and expulsion of air is facilitated by releasing or
replacing the vent cap 187 onto the vent 188 in the housing 179.
Solvent in the chamber 184, a small segment of embolic agent 1 may
result in dissolution of the enclosed segment of capsule.
[0250] Details of an example of the interfaces between components
such as embolic delivery systems 324 using feeder rollers 325
rotating on shafts 333, side port adaptors 530, and introducer
catheters 200 are shown in 3 frontal views in FIGS. 27A-B. FIG. 27A
shows a modified side port adaptor 530 with a rotating locking hub
532 that can connect detachably with the hub 201 of an introducer
catheter 200 that has a wall 208 and lumen 209. The side port
adaptor 530 has a wall 543 and lumen 541 and a side port 535, as
well as an internal constricting O-ring 537 that is controlled by a
rotating O-ring constrictor 538 accessible to the operator. There
is an introducer element 347 which is a tube-like extension that
accepts the embolic agent 1 and may have two different outer
diameters as shown, to provide a small outer diameter that allows
it to be positioned in very close proximity to the feeder rollers
325 that rotate on their shafts, with said close positioning
serving to prevent kinking or buckling of the embolic agent 1.
Discussion of introducer element and embodiments were shown also in
FIGS. 16D-G. The O-ring constrictor 538 is a conventional element
which is used in this novel device here to maintain fluid-tight
seal when desired, while being adjustable to find the best balance
between seal and friction of sufficiently small degree against the
embolic agent 1 so as to permit its useful motion through the
system. Here it is shown constricted, without embolic agent inside
its core, such as might occur when the system is being flushed with
fluid through the side port 535. FIG. 27B shows the same device
with the introducer catheter 200 attached, the O-ring 537 opened,
and the embolic agent 1 moving forward through the system as
indicated by the solid arrow and the curved arrows showing feeder
roller 325 rotation. This system represents a relatively simple and
economical system from manufacturing aspect that nevertheless
provides many of the useful aspects of the invention including
ability to deliver very long embolic agent 1, flush the system, and
detach members for introduction of other elements or performance of
various other maneuvers commonly performed in practice. In one
contemplated embodiment, a hemostatic valve (not shown) may be
substituted for the O-ring constrictor 538. Whichever type of seal
is used, it is advantageous to be capable of withstanding the
hydraulic force of forceful injection of fluid into the side port
535 without allowing backflow.
[0251] FIGS. 28A-D details a concept of coil shape utilizing the
thermal memory properties of nickel titanium alloy, or nitinol,
which can be used to facilitate the objectives of this invention,
with regard to the feeding of the embolic agent 1 through the
system, which favors a straight filamentous shape, while also
having the benefits of more complex geometries as described herein
once the embolic agent 1 is within the body cavity. Nitinol may be
formulated to be relatively straight or with very weak shape memory
at room temperature, but resume a more robust shape memory, of
geometry determined at manufacture, at body temperature. This
remarkable property has been used with success for a commercial
intravenous filter that passed through a catheter as a single wire
and formed a complex functional shape in the body. FIG. 28A
includes sequential frontal views of an embolic agent 1 with a
Nitinol wire 6 in a capsule 43 of polymer, which is substantially
straight at room temperature and when constrained within an
introducer catheter (not shown), but when introduced into the warm
body (not shown), as indicated by the arrow, resumes its
pre-determined memory shape, in this case a series of loops. This
embolic agent 1 may be modified by the operator and undergo
electrolytic detachment as described herein. Nearly any variation
of embolic agent 1 composed of an encapsulated wire described
herein could be made using Nitinol substituting for stainless
steel. The Nitinol will not usually be used to serve the functions
often described for metals such as platinum or gold as markers or
electrical contacts. FIG. 28B includes sequential frontal views
depicting a variation whereby a small diameter strand of stainless
steel wire 6 is used as described previously, to permit
electrolytic detachment. It is centrally located in the capsule 43.
A second wire 62, composed of Nitinol, is eccentrically located in
the capsule and never touches the central wire 6. The arrow
indicates modification by the operator using embolic detachment
tools (not shown) which removes a portion of the capsule 43 as
previously described, creating a bare portion 39 of wire 6, and
also cut the eccentric second wire 62 of Nitinol. Electrolytic
detachment or mechanical detachment may occur using means described
in this invention. In the body cavity, the second wire 62 of
Nitinol provides the shape memory function described above, causing
the embolic agent 1 to be looped at body temperature as shown in
FIG. 28A. FIG. 28C includes sequential frontal views showing the
concept being applied to a helical wire 33 made of Nitinol. The
embolic agent 1 is substantially straight or with weak shape memory
at room temperature on the left, but as shown by the arrow, assumes
a looped memory shape once deployed in the body. FIG. 28D includes
sequential views and frontal view showing an embolic agent 1
composed of a helical wire 33 which need not have shape memory,
with a Nitinol wire 6 centrally attached at proximal end 18 and
distal end 19 of the embolic agent 1, and which is substantially
straight at room temperature and assumes a memory shape at body
temperature, creating loops as seen on the right. In other
contemplated embodiments, any of the embolic agents in FIGS. 28A-D
may also combine other described aspects of this invention, and may
have a variety of possible memory shapes they assume.
[0252] Various embodiments of the invention disclosed herein are
further described as follows.
[0253] An embolic agent apparatus, comprising an embolic agent with
at least two or more segments, each segment of the embolic agent
having a proximal end, a middle portion, and a distal end; and, a
detachment element separating each embolic agent segment operable
to provide a detachment site selectable by the operator.
[0254] The apparatus as above further comprising a linking element
operable to connect the proximal end of the embolic agent to a
detachment element associated with the distal end of a pusher
element operable to allow the operator to orient the embolic agent
with bi-directional motion. The apparatus of as above further
comprising a linking element operable to link the proximal end of
the embolic agent with the distal end of the detachment element
operable to advance the detachment site of the embolic agent
intracorporeally.
[0255] The apparatus as above wherein the embolic agent includes at
least one node located between the distal and proximate ends of at
least one segment of the embolic agent. The apparatus as above
wherein the embolic agent includes at least one notch located
between the distal and proximate ends of at least one segment of
the embolic agent. The apparatus as above wherein the detachment
element is selected from the group consisting of a mechanical
detachment element, an electrolytic detachment element, a
bi-directional locking element, a heat sensitive adhesive, a heat
deformable metal, a corrodible metal, a dissolvable metal, and a
dissolvable polymer. The apparatus as above wherein the embolic
agent is selected from the group consisting of a monofilament, a
multifilament, a helical wire, an encapsulated wire, a coated
helical wire, a chemically dissolvable polymer, an electrolytically
corrodible wire, a polymer, a metal wire, a polyglycolide, a
polylactide, a poly L-lactide, a poly DL-lactide, a
poly-caprolactone, and a copolymer. The apparatus as above wherein
at least one segment of the embolic agent includes a removable
seal. The apparatus as above wherein the embolic agent further
comprises a wire within the body of the embolic agent capable of
conducting electrical current. The apparatus as above wherein the
embolic agent further comprises a traction element located on a
surface of the embolic agent. The apparatus as above further
comprising a linking element with an attachment pin and the linking
element positioned between the embolic agent and the detachment
element. The apparatus as above wherein the linking element
includes a traction element applied to the attachment pin wherein
the traction element is selected from the group consisting of a
barb, a ridge, an attachment pin, a curved attachment pin, a
frictional roughness, and a threaded connection. The apparatus as
above wherein the detachment element is one selected from the group
consisting of an adhesive, a sealant, a chemically corrodible
polymer, an electrolytically corrodible metal, a polymer,
polyglycolide, a polylactide, a poly L-lactide, a poly DL-lactide,
a poly-caprolactone, and a copolymer. The apparatus as above
wherein the detachment element or embolic agent is modified with an
embolic detachment tool selected from the group consisting of a
spark generator, a heat gun, a sander, a shaper, a wire stripper, a
dissolution chamber, a swage tool, an adhesive, a heat chamber, a
scissor or a blade. The apparatus as above wherein the comprising a
catheter for guiding the embolic agent to the target tissue wherein
the catheter includes an electrical current conducting wire secured
within the wall of the catheter up to the catheter tip, operable to
allow the operator to place the tip of the catheter at the desired
detachment element and electrolytically detach the embolic agent
intracorporeally. The apparatus as above wherein the comprising a
catheter for guiding the embolic agent to the target tissue wherein
the catheter delivers a solvent to the selected detachment element,
operable to allow the operator to place the tip of the catheter at
the desired detachment element and chemically detach the embolic
agent intracorporeally.
[0256] A catheter apparatus comprising a lumen and a wall forming a
tube structure with a proximal end, a middle portion and a distal
end; at least one wire encapsulated within the wall portion capable
of conducting electricity; and, a contact attached to the proximal
end of the tube and a contact attached to the distal end of the
tube so as to provide electrical energy to an embolic agent, a
detachment element or the local ionic medium.
[0257] An embolic delivery system, comprising a drive pulley
attached to a drive shaft, a timing pulley and a feeder roller
attached to a pulley shaft; a catheter or embolic agent oriented
between at least two feeder rollers; and, a timing belt in
mechanical communication with the drive pulley and timing pulley
operable to bi-directionally move the catheter or embolic agent
toward a target tissue.
[0258] An embolic delivery system, comprising a drive pulley
attached to a drive shaft, a timing pulley and a feeder belt
attached to a pulley shaft; a catheter or embolic agent oriented
between at least two feeder belts; and, a timing belt in mechanical
communication with the drive pulley and timing pulley operable to
bi-directionally move the catheter or embolic agent toward a target
tissue.
[0259] The apparatus as above wherein at least one feeder roller
includes a groove around its circumference to assist in feeding and
providing traction between the feeder roller and the catheter or
embolic agent.
[0260] An embolic delivery system, comprising a rotatable cylinder
with at least one feeder chute is on the surface of the cylinder
with an inlet port for accepting an embolic agent; and, a
concentric wall opposing the cylinder surface operable to retain
the embolic agent inside the feeder chute as the cylinder is
rotated.
[0261] A method for implanting an embolic agent, comprising
inserting an embolic agent securably linked to a detachment element
into an introducer catheter; propelling the embolic agent to the
target tissue; and, detaching the embolic agent at the target
tissue. The method as above further comprising securing a pusher
element and the embolic agent with a traction element. The method
as above further comprising propelling the embolic agent with a
mechanical embolic delivery system. The method as above further
comprising propelling the embolic agent with a hydraulic embolic
delivery system. The method as above of further comprising
modifying the embolic agent with an embolic detachment tool. The
method as above wherein the embolic detachment tool is selected
from the group consisting of a spark generator, a heat gun, a
sander, a shaper, a wire stripper, a dissolution chamber, a swage
tool, an adhesive, a heat chamber, a scissor or a blade.
[0262] An embolic delivery apparatus, comprising a cylindrical
piston operable to push an embolic agent along a track; a trolley
in mechanical communication with the piston via a rack, a pinion, a
pinion shaft, a reel, a tether, a tether guide, a clutch, a clutch
arm, a spring and a spring mount operable to translate the
bi-directional motion of the trolley by the operator's hand
movement.
[0263] An embolic agent apparatus, comprising a non-segmented
variable length embolic agent with a proximal end, a middle
portion, and a distal end; and, at least one detachment element
located continuously along the length of the embolic agent at which
the operator may select the detachment site at any location along
the length of the embolic agent.
[0264] An embolic agent apparatus, comprising a thermally reactive
wire incorporated into an embolic agent wherein the thermal wire
includes shape memory such that the embolic agent is substantially
linear in the extracorporeal environment and upon introduction into
the intracorporeal environment at elevated temperature the embolic
agent assumes a complex memory shape. An embolic delivery
apparatus, comprising a cam gripper providing a grip around the
circumference of the embolic agent in the forward linear direction
for advancement of the embolic agent and releasing the grip on the
embolic agent when the cam gripper is moving in the opposite linear
direction. An embolic agent apparatus, comprising an embolic agent
with a distal end, a middle portion, and a proximal end, including
a larger surface contact area on the proximal end and the distal
end of the embolic agent providing for axial movement of the
embolic agent.
[0265] While the invention has been particularly shown and
described with reference to a various embodiments, it will be
understood by those skilled in the art that various changes in form
and detail may be made therein without departing from the spirit
and scope of the invention.
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