U.S. patent application number 11/169322 was filed with the patent office on 2006-04-13 for intracorporeal occlusive device and method.
Invention is credited to Michael P. Marks, Michael Ross.
Application Number | 20060079929 11/169322 |
Document ID | / |
Family ID | 23265963 |
Filed Date | 2006-04-13 |
United States Patent
Application |
20060079929 |
Kind Code |
A1 |
Marks; Michael P. ; et
al. |
April 13, 2006 |
Intracorporeal occlusive device and method
Abstract
An intracorporeal space filling device and a delivery system and
method of using the device is disclosed. The space filling device
is preferably configured for percutaneous delivery from a
peripheral conduit of a patient. The space filling device has an
elongated tubular or interconnected bead structure which may have a
transmutable material disposed within it. The transmutable material
can be altered from a non-rigid state to a rigid state by the
application of various types of energy or by other suitable means.
The space filling device can be positioned by a delivery system and
detached from the delivery system after desired positioning is
achieved.
Inventors: |
Marks; Michael P.;
(Hillsborough, CA) ; Ross; Michael; (Hillsborough,
CA) |
Correspondence
Address: |
KNOBBE MARTENS OLSON & BEAR LLP
2040 MAIN STREET
FOURTEENTH FLOOR
IRVINE
CA
92614
US
|
Family ID: |
23265963 |
Appl. No.: |
11/169322 |
Filed: |
June 28, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11033463 |
Jan 11, 2005 |
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11169322 |
Jun 28, 2005 |
|
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10106511 |
Mar 25, 2002 |
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11033463 |
Jan 11, 2005 |
|
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09324987 |
Jun 2, 1999 |
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10106511 |
Mar 25, 2002 |
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Current U.S.
Class: |
606/200 |
Current CPC
Class: |
A61B 17/12022 20130101;
A61B 17/12145 20130101; A61B 2017/12068 20130101; A61B 17/12195
20130101; A61B 2017/22068 20130101; A61B 2017/00867 20130101; A61B
17/1214 20130101; A61M 2025/1052 20130101; A61B 2017/22069
20130101; A61B 2017/12077 20130101; A61B 17/12163 20130101; A61B
17/12109 20130101; A61B 17/12113 20130101; A61B 2017/12063
20130101; A61B 2017/00477 20130101; A61B 2017/12072 20130101; A61B
17/12136 20130101 |
Class at
Publication: |
606/200 |
International
Class: |
A61M 29/00 20060101
A61M029/00 |
Claims
1. A method of occluding an intracorporeal void, comprising: (a)
positioning the distal end of a microcatheter such that a distal
port in the distal end is directed to the cavity of the
intracorporeal void; (b) distally advancing an intracorporeal space
filling device comprising: an elongate tubular shell which has a
first port disposed at a first end and a second port disposed at a
second end and an inner lumen disposed within the shell in fluid
communication with the first port and second port; and a
transmutable material disposed within the inner lumen of the shell
that is transmutable from a non-rigid state to a substantially
rigid state within the patient's body, (c) deploying the space
filling device into the void (d) transmuting the transmutable
material from a non-rigid state to a substantially rigid state; (e)
detaching the space filling device from the delivery system by
activation of a detachment mechanism after the space filling device
has been positioned with the intracorporeal void.
Description
[0001] This application is a continuation of application Ser. No.
11/033,463, filed Jan. 11, 2005, which is a continuation of
application Ser. No. 10/106,511, filed Mar. 25, 2002, which is a
divisional application of application Ser. No. 09/324,987, filed
Jun. 2, 1999; The disclosures of these prior applications are
incorporated in their entirety herein by this reference.
BACKGROUND
[0002] The present invention is generally directed to occlusion
devices and, more specifically, to intracorporeal occlusion devices
which can be used to treat a patient's blood vessels,
intracorporeal conduits or other portions of a patient's body. A
preferred embodiment can be used to treat intracranial aneurysms,
arteriovenous fistulas, and other abnormalities within the cerebral
vasculature.
[0003] Cerebral aneurysms and other cerebral vascular abnormalities
present a significant medical problem to the population of the
United States. It is estimated that the number of ruptured
intracranial aneurysms yearly is in the tens of thousands, often
with devastating consequences for the patient. For a patient who
has been diagnosed with a cerebral aneurysm, there are a few
treatment modalities currently available. An invasive surgical
treatment can be used where access to the external portion of the
aneurysm is achieved by placing the patient under general
anesthesia, performing a craniotomy, and brain tissue retraction.
Once access has been gained to the external surface of the
aneurysm, the neck of the aneurysm can be clipped. Clipping the
aneurysm neck prevents the ingress of blood into the aneurysm
cavity which can lead to rupture. Because of the invasive nature of
the procedure and the vulnerability of the brain tissue surrounding
the aneurysm, this procedure carries a high degree of risk with
concomitant mortality and morbidity rates. This risk is
particularly high when the aneurysm has ruptured prior to the
surgical intervention.
[0004] An alternative to the surgical method currently in use
involves percutaneous endovascular intervention. This method
generally involves accessing the cerebral aneurysm by means of an
intravascular microcatheter which is advanced under flouroscopic
imaging over a guidewire or the like within the patient's arteries
from a puncture site in the patient's leg or arm. The distal end of
the microcatheter is guided over a guidewire within a patient's
vasculature and disposed adjacent the neck of the aneurysm. The
distal tip of the microcatheter can then be directed into the
cavity of the aneurysm and appropriate occlusive devices then
delivered from a port in the distal end of the microcatheter.
Presently, the most common occlusive device delivered via
microcatheter is a vaso-occlusive coil which consists of stainless
steel or radiopaque metals such as gold or platinum, tantalum. The
vaso-occlusive coils are typically manufactured in a manner similar
to the distal coils of a coronary guidewire, having a coil wire
material with a small diameter and a coil outer diameter suitable
for delivery through a microcatheter. Such vaso-occlusive coils are
often given a secondary shape or configuration whereby the coils
cab be straightened and delivered through the inner lumen of a
microcatheter, but form a convoluted or random space filling
structure once delivered from the distal end of the microcatheter.
The endovascular delivery of vaso-occlusive coils through a
microcatheter represents a significant advance in treating cranial
aneurysms. However, the coils are hollow bodies, often made of
relatively soft metals which are subject to compaction due to the
pressure exerted on the deployed coils by the patient's blood flow.
Compaction and reforming of the coils leaves them susceptible to
dislodging and being displaced within the patient's vasculature,
with the potential for causing distal embolization. In addition,
compaction of the coils into the dome of the aneurysm or blood clot
surrounding the coils can lead to reappearance and regrowth of the
aneurysm. Finally, aneurysms with wide necks having a dome to neck
dimension ratio of less than 2 to 1 often do not provide a
morphology conducive to retention of coils within the aneurysm.
Thus currently available coils are generally contraindicated for
use in wide neck aneurysms. What has been needed is an
intracorporeal space filling device which can be delivered by
non-invasive methods, is not subject to compaction or reforming and
which is suitable for implantation in wide neck aneurysms.
SUMMARY
[0005] The invention is directed generally to an intracorporeal
space filling device and a delivery system for positioning and
deploying the space filling device within a patient. The invention
is also directed to a method for using the space filling
device.
[0006] One preferred embodiment of the invention is an
intracorporeal space filling device which has an elongate tubular
shell with a lumen disposed within the shell. The lumen is in fluid
communication with a first port in a first end of the shell, and a
second port in a second end of the shell. A transmutable material
is disposed within the lumen of the shell substantially filling the
lumen. The transmutable material has properties which enable
transformation from a non-rigid state to a substantially rigid
state within a patient's body. The transmutable character of the
transmutable material allows for a space filling device that is
soft and flexible at the time of deployment into an intracorporeal
cavity and rigid and substantially incompressible after being
converted to a rigid state. Such a device can conform readily to
the varied morphology of intracorporeal cavities and transmute to a
substantially rigid mass upon activation or hardening of the
transmutable material so as to be resistant to compression and
reforming due to vascular or other types of pressures within a
patient's body.
[0007] The elongate shell is generally made of a polymeric wall
material and is sealed at either or both of the first and second
ends. The transmutable material which fills the lumen of the shell
can be selected from a variety of suitable polymers which can be
made rigid or hardened by the application of a variety of energy
types, such as light emitted from a laser or other source,
radiofrequency energy, ultrasonic energy or other suitable means
such as controlled changes in the pH of the material surrounding
the transmutable material. The space filling device is typically
configured for percutaneous delivery through a suitable
microcatheter from an incision in a peripheral artery in a
patient's arm or leg to a desired intracorporeal cavity, such as a
cerebral aneurysm.
[0008] Optionally, the space filling device may have an elongated
longitudinal member secured to and preferably coextensive with the
elongate tubular shell of the device. Typically, the elongated
longitudinal member is a thin wire member that may or may not be
configured to give a secondary shape to the space filling device
when in an unconstrained relaxed state. The secondary shape of the
longitudinal member can be a convoluted, folded, coiled or twisted
configuration or any other suitable space filling configuration
when in an unconstrained state which is imparted to the
intracorporeal space filling device to which the elongated
longitudinal member is secured. When the device is in a linear
constrained state or configuration, it may be advanced through an
inner lumen of a microcatheter or other similar device for delivery
to a desired site within a patient's body. Once the space filling
device is removed from the constraint of the microcatheter, it
again assumes the space filling secondary shape. The elongated
longitudinal member can be made from a variety of suitable
materials, including stainless steel and shape memory alloys such
as nickel titanium (NiTi). The elongated longitudinal member can be
disposed along a longitudinal axis of the space filling device,
embedded in the transmutable material, encapsulated within the wall
material of the elongate tubular shell, or adjacent an outside
surface of the elongate tubular shell or any other suitable
location on the device. Preferably the elongate longitudinal member
is substantially parallel to the longitudinal axis of the elongate
shell or intracorporeal space filling device. The elongated
longitudinal member can also be configured to be heated by the
passage of various types of energy therethrough. For example, an
elongated longitudinal member made of NiTi alloy can be configured
to be heated by the passage of electrical current, including
radiofrequency, or ultrasonic energy through it. Heating of the
elongated longitudinal member can be used to transmute or rigidify
the transmutable material within the elongate shell and to act as a
mechanism for detachment of the intracorporeal space filling device
from the distal end of the delivery system.
[0009] In a preferred embodiment, the elongate tubular shell is
configured to have an outer surface which is self adhering to
create attachment points from contact point upon activation of the
self adhering outer surface. Contact points along the length of the
space filling device inevitably occur when the device is deployed
within an intracorporeal cavity or channel and the space filling
device assumes a folded or convoluted space filling configuration.
The folded or convoluted space filling configuration may be due to
the confinement of the void or channel, a secondary shape assumed
by the device in a relaxed state, or both. The creation of
attachment points results in a more rigid and stable space filling
mass that is resistant to compaction and reforming.
[0010] The intracorporeal space filling device may optionally have
a helical coil disposed about an outer surface of the elongate
tubular shell. The helical coil may have properties similar to
those discussed above with regard to the elongated longitudinal
member. For example, the helical coil can be configured to impose a
convoluted, folded or space filling secondary shape on the space
filling device when in a relaxed unconstrained state. The helical
coil may also be configured to heat or otherwise activate
transmutation of the transmutable material when various forms of
energy are passed through it such as electrical current, ultrasonic
energy or the like. The materials of the helical coil may also be
similar to those discussed above with regard to the elongated
longitudinal member.
[0011] In an alternative embodiment, the space filling device has a
transmutable material disposed about an elongated longitudinal
member without an outer shell so that the transmutable material is
exposed when the device is deployed within a patient's body. The
elongated longitudinal member can have properties similar to those
of the elongated longitudinal members discussed above. For example,
the elongated longitudinal member can be made of a thin wire with a
secondary shape. The secondary shape can be imparted on the space
filling device when the device is in an unconstrained state.
Secondary shapes can include convoluted or folded space filling
configurations. Exposure of an outside surface of the transmutable
material allows the transmutable material to adhere to itself upon
transmutation at attachment points where different portions of the
space filling device make contact due to the secondary shape
assumed. When the space filling device is deployed in an
intracorporeal cavity and assumes a folded, bunched or convoluted
configuration due to a secondary shape of the elongated
longitudinal member or the natural confinement of the cavity,
inevitably, certain portions of the space filling device will make
physical contact with other portions of the device. As such, the
transmutable material of these portions will make contact at
contact points and will cross-link, bond, or self adhere to each
other to form attachment points upon transmutation of the
transmutable material. The cross-linking or bonding of the device
at attachment points results in a rigid mass which is resistive to
compression and reforming. The self adhering property of the
outside surface of the transmutable material can be as a result of
the intrinsic properties of the transmutable material, or as a
result of a coating applied to the transmutable material with self
adhering properties.
[0012] In another embodiment, the intracorporeal space filling
device has a plurality of beads connected to at least one adjacent
bead by a flexible member with connections to adjacent beads being
configured to produce a linear array of the beads. Each bead has a
transverse dimension and is generally spaced within one transverse
dimension of adjacent beads, however, other appropriate spacings
are possible. The space filling device of interconnected beads is
generally configured for percutaneous delivery through a
microcatheter or the like from an incision in a peripheral artery
of a patient to a desired cavity within the patient's vasculature
such as a cerebral aneurysm. The individual beads typically have a
generally spherical shape, but can also be substantially elliptical
or elongated. The beads can be made from any suitable material, but
are preferably made from a polymer material, and more preferably a
transmutable polymer material. In a particular embodiment, the
beads may have an outer shell which defines a cavity which
optionally contains suitable filler material. Suitable filler
materials include biocompatible fluids such as a saline, silicone
and the like, and polymers such as a transmutable material similar
to the transmutable material discussed above.
[0013] Embodiments with beads of exposed transmutable material can
be cross-linked or bonded to adjacent beads which are in contact at
the time of transmutation at a desired site within a patient's
body. Adjacent beads in contact while deployed within a desired
location within a patient can adhere or bond together and create
attachment points upon transmutation of the transmutable material.
The attachment points create a more stable and rigid mass than
would be achieved by transmutation of the beads without attachment
points.
[0014] The flexible member connecting adjacent beads may consist of
interconnected portions of a polymer wall material of the outer
shell of each adjacent bead. The flexible member may also be an
elongated longitudinal member disposed substantially along a
longitudinal axis of thp space filling device and being
substantially coextensive with at least two adjacent beads of the
space filling device. In embodiments of the space filling device
having a flexible member consisting of an elongated longitudinal
member, the elongated longitudinal member may be a thin wire,
preferably of a shape memory alloy. The thin wire longitudinal
member can be configured to be heated by a passage of energy
through it in order to activate transmutation of transmutable
material disposed thereon. The elongated longitudinal member may
also be configured to have a secondary shape or space filling
configuration in a relaxed state as discussed above with regard to
other elongated longitudinal members. The secondary shape or space
filling configuration of the elongated longitudinal member would be
imparted to the space filling device as a whole when in an
unconstrained relaxed state.
[0015] The intracorporeal space filling devices discussed above are
generally deployed at a desired site within a patient's body by
disposing the distal end of a microcatheter or the like such that a
distal port in the distal end of the microcatheter is directed to a
desired cavity or channel within a patient. The space filling
device is then distally advanced within the inner lumen of the
microcatheter, preferably by means of a delivery system which has
an elongate shaft with a detachment mechanism disposed on the
distal end of the system. The detachment mechanism is detachably
secured to a first end of the space filling device which provides a
detachable connection and allows for remote advancement and
retraction of the space filling device within the patient prior to
detachment. The space filling device is then distally advanced out
of a port in the distal end of the microcatheter and into the
cavity or channel of the patient. When the space filling device is
appropriately positioned, the transmutable material within the
device is activated so as to be hardened or rigidified, and the
device detached from the delivery system. Preferably, the space
filling device is detached by a detachment mechanism utilizing
degradation of a polymer link between the delivery system and the
first end of the space filling device. Degradation of the polymer
link may be accomplished by a chain cleavage reaction which can be
initiated by heating of the polymer link. Alternative detachment
mechanisms include mechanical detachment, electrolytic detachment,
detachment by shape memory alloy or shape memory polymer activation
via application of RF energy, laser energy or ultrasonic energy,
heating of a hot melt adhesive joint, ultrasonic link degradation,
hydrokinetic pressure activation of a mechanical retention device,
and the like.
[0016] During deployment of a space filling device, a blocking
balloon may be deployed adjacent the opening of an intracorporeal
void and distal end of a microcatheter disposed within the void
prior to distally advancing the space filling device from the
distal end of the microcatheter into the cavity. The blocking
balloon prevents egress of the space filling device from within the
cavity during deployment of the device.
[0017] These and other advantages of the invention will become more
apparent from the following detailed description of the invention
when taken in conjunction with the accompanying exemplary
drawings.
BRIEF DESCRIPTION
[0018] FIG. 1 is a longitudinal sectional view of an intracorporeal
space filling device having features of the invention.
[0019] FIG. 2 is a transverse cross sectional view of the
intracorporeal space filling device of FIG. 1 taken at lines 2-2 of
FIG. 1.
[0020] FIG. 3 is a longitudinal sectional view of an intracorporeal
space filling device having features of the invention.
[0021] FIG. 4 is a transverse cross sectional view of the
intracorporeal space filling device of FIG. 3 taken at lines 44 of
FIG. 3.
[0022] FIG. 5 is a longitudinal sectional view of an intracorporeal
space filling device having features of the invention.
[0023] FIG. 6 is a transverse cross sectional view of the
intracorporeal space filling device of FIG. 5 taken at lines 6-6 of
FIG. 5.
[0024] FIG. 7 is a longitudinal sectional view in of an
intracorporeal space filling device similar to the device of FIG.
1, but including an outer coil member.
[0025] FIG. 8 is a transverse cross sectional view of the device of
FIG. 7 taken along lines 8-8 in FIG. 7.
[0026] FIG. 9 is a longitudinal sectional view of an intracorporeal
space filling device having features of the invention.
[0027] FIG. 10 is a transverse cross sectional view of the
intracorporeal space filling device of FIG. 9 taken at lines 10-10
of FIG. 9.
[0028] FIG. 11 is a transverse cross sectional view of the
intracorporeal space filling device of FIG. 9 taken at lines 11-11
of FIG. 9.
[0029] FIG. 12 is a longitudinal sectional view of an
intracorporeal space filling device having features of the
invention.
[0030] FIG. 13 is a transverse cross sectional view of the
intracorporeal space filling device of FIG. 12 taken at lines 13-13
of FIG. 12.
[0031] FIG. 14 is a longitudinal sectional view of an
intracorporeal space filling device having features of the
invention.
[0032] FIG. 15 is a transverse cross sectional view of the
intracorporeal space filling device of FIG. 14 taken at lines 15-15
of FIG. 14.
[0033] FIG. 16 is a schematic view in partial longitudinal section
of a microcatheter over a guidewire disposed within a patient's
blood vessel.
[0034] FIG. 17 is a schematic view in partial section of the distal
end of a microcatheter disposed within the neck of an aneurysm.
[0035] FIG. 18 is a schematic view in partial section of the distal
end of a microcatheter disposed within an aneurysmal cavity with an
intracorporeal space filling device deployed within the
aneurysm.
[0036] FIG. 19 is a schematic view in partial section of a blocking
balloon deployed adjacent an aneurysm with the distal end of a
microcatheter disposed within the aneurysm and an intracorporeal
space filling device disposed within the aneurysm.
[0037] FIG. 20 is an elevational view in partial section of a first
end of an intracorporeal space filling device detachably secured to
a distal end of a delivery system having features of the
invention.
[0038] FIG. 21 is an elevational view in partial section of a first
end of an intracorporeal space filling device detachably secured to
a distal end of a delivery system having features of the
invention.
[0039] FIG. 22 is an elevational view in partial section of a first
end of an intracorporeal space filling device detachably secured to
a distal end of a delivery system having features of the
invention.
[0040] FIG. 23 is an elevational view in partial section of a first
end of an intracorporeal space filling device detachably secured to
a distal end of a delivery system having features of the
invention.
[0041] FIGS. 24-26 depict an alternative embodiment of a capture
element for detachment of the space filling device.
DETAILED DESCRIPTION
[0042] FIG. 1 illustrates an intracorporeal space filling device 10
having features of the invention. The intracorporeal space filling
device 10 has an optional elongate tubular shell 11 with a first
end 12 and a second end 13, the elongate shell being formed of a
wall material 14. There is a lumen 15 disposed within the elongate
tubular shell 11 which has transmutable material 16 disposed
therein.
[0043] The elongate tubular shell 11 can be made from a variety of
materials including metals and polymers. Suitable metals for the
elongate tubular shell include stainless steel, NiTi, gold,
platinum, tantalum, palladium, alloys thereof and the like. If a
metal or other rigid material is used, methods such as forming
slots or grooves in the wall material of such an elongate tubular
shell may be used to achieve a desired longitudinal flexibility of
the elongate tubular shell 11. Suitable polymers for the elongate
tubular shell 11 can include polyurethane, polyethylene, nylon,
polyimide, polyamide, polytetraflouroethylene, polyester,
polypropylene and the like. The elongate tubular shell 11 may be
sealed and impermeable to the transmutable material 16, so as to
prevent the egress of the transmutable material from within the
shell to the surrounding environment.
[0044] In one preferred embodiment, the elongate tubular shell 11
has at least one aperture which exposes the transmutable material
16 and allows the transmutable material to make contact with
adjacent portions of the space filling device or other space
filling devices so as to permit self adhering or bonding upon
transmutation of the transmutable material. The apertures in the
elongate tubular shell 11 can be in the form of transverse or
longitudinal slots or grooves, circular or otherwise configured
holes, or the like. The apertures may be relatively far apart
relative to the size of the apertures, or they may be relatively
close together and numerous so as to form a mesh pattern or other
suitable pattern of fenestration which facilitates exposure of the
transmutable material 16 but maintains the overall elongated
structure of the space filling device 10. Similar apertures may be
appropriate for any of the various embodiments of space filling
devices discussed herein having outer shell structures.
[0045] The dimensions of the space filling device 10 and elongate
tubular shell 11 are generally appropriate for percutaneous
delivery via a microcatheter to a desired site within a patient's
vasculature, however, other suitable dimensions and configurations
are contemplated. The length of the space filling device 10, and
all other embodiments of space filling devices discussed herein
generally, can be from about 0.5 to about 50 cm, preferably about 2
to about 30 cm. It should be noted that the morphology of the sites
being filled or otherwise treated by the present invention vary
greatly. Embodiments of the invention for use treating cerebral
aneurysms may be made available in a variety of sizes and lengths
so that most of the anticipated morphologies can be accommodated.
For example, a space filling device 10, and other space filling
devices discussed herein generally, configured for treatment of
cerebral aneurysms, or the like, may be made available in lengths
of 2, 5, 10, 15, 20, 25, 30, 35 and 40 cm. In this way, a wide
range of aneurysm volumes can be appropriately treated.
[0046] A transverse dimension of the space filling device 10, and
of all other embodiments of space filling device discussed herein
generally, can be from about 0.005 to about 0.25 inches, preferably
about 0.01 to about 0.038 inches, and more preferably about 0.014
to about 0.018 inches. In other preferred embodiments of the
invention, the transverse dimension of the space filling device can
be from about 0.004 to about 0.02 inches, preferably about 0.008 to
about 0.012 inches. The thickness of the wall material 14 of the
elongate tubular shell 11 can be from about 0.0001 to about 0.01
inches, preferably about 0.0005 to about 0.002 inches, and more
preferably about 0.001 to about 0.0015 inches.
[0047] The transmutable material 16 disposed within the elongate
tubular shell 11 is preferably a material that can be transmuted by
polymerization, crystallization or other suitable process from a
non-rigid liquid, gel or granular state to a rigid state Some of
the materials suitable for this application are discussed generally
in U.S. Pat. No. 5,334,201, K. Cowan, and U.S. Pat. No. 5,443,495,
P. Buscemi, et al., which are hereby incorporated by reference in
their entirety. Transmutation of the transmutable material can be
achieved or activated by the application of a suitable type of
energy to the transmutable material. Suitable types of energy
include electromagnetic energy in the form of light, DC current, AC
current, RF current or the like in addition to ultrasonic energy.
Energy may also be applied directly or indirectly in the form of
heat to cause transmutation. Transmutation may also be activated by
altering the chemistry of the environment surrounding the
transmutable material such as by changing the pH or by injection of
a catalyst into the transmutable materials, either directly or
indirectly by injection or introduction into the surrounding tissue
or bodily fluid such a blood. With regard to the embodiment of FIG.
1, laser or RF energy is preferably applied to the outer surface of
the elongate tubular shell and transmutable material to cause
transmutation. The outer dimensions of the transmutable material 16
are generally similar to the cavity dimensions of the elongate
tubular shell 11. As an alternative to the transmutable material
16, any suitable biocompatible filler material may be used such as
saline, silicone or the like. Such alternative filler materials may
be used within any of the suitable embodiments of space filling
devices described herein, either as an alternative to a
transmutable material, or in addition to a transmutable material.
Embodiments of the invention suitable for alternative filler
materials are generally those embodiments having a shell structure
configured to confine the alternative filler materials.
[0048] In embodiments of the space filling device 10 where the
transmutable material 16 is exposed, that is, where the optional
elongate tubular shell 11 is not present, or portions of the
elongate tubular shell 11 are not present at aperture sites, it is
preferable that the transmutable material 16 be self adhering in a
fluid field, such as blood or saline. In this way, when the device
10 is deployed within an intracorporeal cavity or channel and folds
back on itself as a result of the confinement of the cavity or
channel, any contact points between transmutable material where the
device is folded on itself and making mechanical contact will
become attachment points upon transmutation of the transmutable
material by bonding or adhering to itself at the contact points.
The attachment points result in a more stable space filling mass
that is resistant to compaction and reforming.
[0049] Suitable substances generally for the transmutable material
16 include methacrylate compounds, linear polyester, silicone,
cyanoacrylates, polyisocyanate, u.v. curable acrylates, moisture
cure silicones, dimethyl sulfoxide, thioisocyanate aldehyde,
isocyanate, divinyl compounds, epoxide acrylates, succinimidyl
azido salicylate, succinimidyl azidobenzoate, succinimidyl dithio
acetate, azidoiodobenzene, flouronitrophenylazide, salicylate
azides, benzophenonemaleimide, and the like.
[0050] FIG. 2 is a transverse cross sectional view of the
intracorporeal space filling device 10 of FIG. 1. The transmutable
material 16 is disposed within the optional elongate tubular shell
11 of the device. The cross section of FIG. 2 is shown as
substantially round, however, other suitable cross sectional
configurations can be used such as elliptical, triangular or
square.
[0051] FIGS. 3 and 4 illustrate an intracorporeal space filling
device 20 similar to the embodiment of FIG. 1, with the addition of
an elongated longitudinal member 21 disposed along a longitudinal
axis 22 of the optional elongate tubular shell 23. The materials,
dimensions, and features of the elongated tubular shell 23 of FIGS.
3 and 4 can be similar to those of the elongated tubular shell 11
of FIGS. 1 and 2. The materials and dimensions of the transmutable
material 24 can be similar to those of the transmutable material 16
discussed above. Typically, the elongated longitudinal member 21 is
a thin wire member that is configured to give a secondary shape to
the space filling device when in an unconstrained relaxed state.
The longitudinal member 21 can have a secondary shape of a
convoluted, folded, coiled or twisted configuration or any other
suitable space filling configuration when in an unconstrained
state. This configuration is imparted to the intracorporeal space
filling device 20 to which the elongated longitudinal member 21 is
secured. When the device 20 is in a linear constrained state or
configuration, it may be advanced through an inner lumen of a
microcatheter or other similar device for delivery to a desired
site within a patient's body. Once the space filling device 20 is
removed from the constraint of the microcatheter, it again assumes
the space filling configuration. The space filling device 20, and
all other space filling devices described herein generally which
are configured to have a secondary space filling shape, may have a
variety of nominal transverse dimensions or diameters when in a
secondary shape. In order to conform to a wide variety of
intracorporeal morphologies, the space filling device may have a
secondary shape with a transverse dimension of between about 1 to
about 20 mm. A typical space filling device maybe made with a
secondary shape having a transverse dimension of between 1 and 20
mm, in 1 mm increments.
[0052] The elongated longitudinal member 21 can be made from a
variety of suitable materials, including stainless steel and shape
memory alloys such as nickel titanium (NiTi). The length of the
elongated longitudinal member 21 can be from about 0.5 to about 50
cm, preferably about 1 to about 20 cm, and more preferably about 5
to about 15 cm. It is preferable that the elongated longitudinal
member 21 be coextensive with the length of the elongated tubular
shell 23 and with the space filling device generally. Thus, the
elongated longitudinal member may have any of the lengths discussed
herein with regard to space filling devices. The transverse
dimension of the elongated longitudinal member 21 can be from about
0.0005 to about 0.01 inches, preferably about 0.001 to about 0.003
inches, and more preferably about 0.0015 to about 0.002 inches. The
cross section of the elongated longitudinal member is generally
round, however, other configurations are contemplated. Alternative
cross sectional shapes for the elongated longitudinal member
include elliptical, rectangular, as would be found if a flat ribbon
wire used, triangular, square and the like. The various cross
sections can be chosen to give a desired preferred bend axis or
axes along the length of the member. Preferably the elongate
longitudinal member is substantially parallel to the longitudinal
axis 22 of the elongate shell or intracorporeal space filling
device. The elongated longitudinal member 21 can also be configured
to be heated by the passage of various types of energy
therethrough. For example, an elongated longitudinal member 21 made
of NiTi alloy can be configured to be heated by the passage of
electrical current through it. Heating of the elongated
longitudinal member 21 can be used to transmute or rigidify the
transmutable material within the elongate tubular shell 23 and to
act as a mechanism for detachment of the intracorporeal space
filling device 20 from a distal end of a delivery system.
[0053] FIGS. 5 and 6 show an embodiment of an intracorporeal space
filling device 30 similar to the embodiment of FIGS. 3 and 4 but
having an elongated longitudinal member 31 encapsulated within a
wall material 32 of the elongated tubular shell 33. The materials,
dimensions and features of the elongated tubular shell 33 and
elongated longitudinal member 31 of FIGS. 5 and 6 are similar to
those of the elongated tubular shell 23 and elongated longitudinal
member 21 of FIGS. 3 and 4. The elongated longitudinal member 31
may also be secured to an outside surface 34 or inside surface 36
of the elongate tubular shell 33 by an adhesive or other suitable
means. A transmutable material 35 disposed within the elongate
tubular shell 33 can have properties and dimensions similar to or
the same as those of transmutable materials 16 and 24 of FIGS. 1-4
above.
[0054] FIGS. 7 and 8 illustrate an intracorporeal space filling
device 40 similar to that of FIGS. 1 and 2, but with a helical coil
41 disposed about an outside surface 42 of the elongated tubular
shell 43. The helical coil 41 of FIGS. 7 and 8 may have some
properties similar to those discussed above with regard to the
elongated longitudinal members 21 and 31 of FIGS. 3-6. The helical
coil 41 can be configured to impose a convoluted, folded or space
filling configuration on the space filling device 40 when in a
relaxed unconstrained state. The helical coil 41 may also be
configured to heat when various forms of energy are passed through
it. The materials of the helical coil 41 can be any suitable metal,
composite or polymer including shape memory alloys such as NiTi or
high strength alloys such as stainless steel. The type and
dimensions of the material from which the helical coil 41 is made
can be similar to the elongated longitudinal member 31 discussed
above. A transmutable material 44 is disposed within the elongated
tubular shell 43 and can have properties similar or identical to
the properties of transmutable materials 16, 24 and 35 of FIGS. 1-6
above.
[0055] FIGS. 9-11 depict an alternative embodiment of an
intracorporeal space filling device 50 having a plurality of beads
51 secured to each other in a linear configuration. The
intracorporeal space filling device 50 has a plurality of beads 51
connected to at least one adjacent bead by a flexible member 52
with connections to adjacent beads preferably being configured to
produce a linear array of the beads. Each bead 51 has a transverse
dimension and is generally spaced within one transverse dimension
of adjacent beads, however, other appropriate spacings are
possible. The space filling device 50 is generally configured for
percutaneous delivery through a microcatheter or the like from an
incision in a peripheral artery of a patient to a desired cavity
within the patient's vasculature such as a cerebral aneurysm. The
individual beads 51 typically have a generally spherical shape, but
can also be substantially elliptical, with the elliptical shape
optionally being elongated longitudinally to a length of multiple
transverse dimensions. The beads 51 can be made from a rigid
homogeneous polymer material, but are preferably made from an outer
shell 53 which defines a cavity 54 such as is shown in FIGS. 9-11.
The outer shell 53 can be made from a variety of materials
including metals and polymers. Suitable metals for the shell 53
include stainless steel, NiTi, gold, platinum, tantalum, palladium,
alloys thereof and the like. If a metal or other rigid material is
used, methods such as forming slots or grooves in the wall material
of the shell may be used to achieve a desired longitudinal
flexibility. Suitable polymers for the shell 53 can include
polyurethane, polyethylene, nylon, polyimide, polyamide,
polytetraflouroethylene, polyester, polypropylene and the like. The
outer shell 53 may have apertures similar to those of space filling
device 10 described above for exposing portions of transmutable
material contained therein which facilitates self adherence and the
creation of attachment points upon transmutation of the
transmutable material.
[0056] The cavity 54 optionally contains a transmutable material 55
similar to the transmutable materials 16, 24, 35 and 44 discussed
above. The transmutable material 55 is preferably a material that
can be transmuted by polymerization, crystallization or other
suitable process from a non-rigid liquid, gel or granular state to
a rigid state. Transmutation of the transmutable material 55 can be
achieved or precipitated by the application of a suitable type of
energy to the transmutable material such as electromagnetic energy
in the form of light, DC current, AC current, RF or ultrasonic
energy. Energy may also be applied directly or indirectly in the
form of heat to cause transmutation. Other methods of causing or
precipitating transmutation can include altering the pH of the
surrounding environment of the transmutable material, or injecting
a catalyst into the transmutable material directly, or indirectly
by injecting a catalyst into the environment of the transmutable
material.
[0057] The dimensions of the space filling device 50 overall are
similar to those of the previously discussed embodiments. The
thickness of the wall material 56 of the outer shell 53 can be from
about 0.0001 to about 0.01 inches, preferably about 0.0005 to about
0.002 inches, and more preferably about 0.001 to about 0.0015
inches. The wall material 56 of the outer shell 53 of the beads 51
and the transmutable material 55 disposed within the outer shell
can be similar to the materials of the elongate tubular shell 11
and transmutable material 16 of the embodiment of FIG. 1.
[0058] The flexible member 52 connecting adjacent beads may consist
of interconnected portions of a polymer wall material 56 of the
outer shell 53 of each adjacent bead as shown in FIGS. 9-11. As
shown in FIGS. 12-13, an intracorporeal space filling device 60 may
have flexible members 61 that consist of portions of an elongated
longitudinal member 62 disposed substantially along a longitudinal
axis 63 of the space filling device 60 and being substantially
coextensive with at least two adjacent beads 64 of the space
filling device. The beads 64 of the space filling device 60 are
made of a polymer material 65 which is a transmutable material. The
exposed outer surface of the transmutable material of the beads 64
is self adhering in a fluid field, such as blood or saline. When
the space filling device 60 is deployed within a body cavity and
folds back on itself as a result of the confinement or secondary
shape, any contact points where the device is folded on itself
making mechanical contact will become attachment points upon
transmutation of the transmutable material of the beads 64. The
attachment points result in a more stable space filling mass which
is resistant to compaction and reforming.
[0059] The elongated longitudinal member 62 may be a thin wire,
preferably of a shape memory alloy that can be configured to be
heated by a passage of energy through it. The elongated
longitudinal member 62 shown in FIGS. 12-13 can have similar
dimensions and properties to the elongated longitudinal members 21
and 31 shown in FIGS. 3-6. These properties can include a secondary
shape, shape memory properties, and heating upon a passage of
energy through the elongate longitudinal member 62. In addition,
the elongated longitudinal member 62 can have a variety of cross
section configuration including round, square, rectangular and the
like.
[0060] FIGS. 14 and 15 depict an intracorporeal space filling
device 66 which has beads 67 attached in a substantially linear
array by an elongate longitudinal member 68. The beads 67 have an
outer shell 69 which is optionally filled with a transmutable
material 69A. The dimensions and materials of beads 67 can be
similar to those of beads 51 discussed above with regard to FIGS.
9-11. The materials and dimensions of longitudinal member 68 can be
similar to those of elongated longitudinal member 62 discussed
above with respect to FIGS. 12 and 13.
[0061] FIGS. 16-19 schematically depict a procedure whereby an
intracorporeal space filling device 70 is deployed within an
intravascular cerebral aneurysm 71 of a patient by percutaneous
means through a lumen 72 of a microcatheter 73. The distal end 74
of microcatheter 73 is advanced over a guidewire 75 through a
patient's vasculature and artery 76 to an aneurysm 71. The space
filling device 70 is then distally advanced within an inner lumen
72 of the microcatheter 73, preferably by means of a delivery
system 77. Delivery system 77 has an elongate shaft 80 with a
detachment mechanism 81 disposed on the distal end 82 of the
system. The detachment mechanism 81 is detachably secured to a
first end 83 of the space filling device 70 which allows proximal
manipulation of the delivery system 77 to control axial advancement
and retraction of the space filling device within the microcatheter
73 and the patient. The space filling device 70 is then distally
advanced out of a port 84 in the distal end 74 of the microcatheter
73 and into the aneurysm 71.
[0062] When the space filling device 70 is appropriately
positioned, transmutable material of device 70 is transmuted to a
rigid state, and the space filling device 70 detached from the
delivery system 77. Transmutation of the transmutable material may
take place prior to during or after detachment of the space filling
device from the detachment mechanism. The space filling device 70
is detached by degradation of a polymer link 85 between the
delivery system 70 and the first end 83 of the space filling
device, preferably by a chain cleavage reaction which can be
initiated by heating of the polymer link 85. Although the
illustrated method of detachment of the space filling device 70 is
chain cleavage degradation of a polymer link 85, any suitable
detachment method may be used. Examples of suitable detachment
methods include mechanical detachment, electrolytic detachment,
shape memory metal or polymer activation via a temperature change
by application of RF energy, laser energy, ultrasonic energy,
heating of a hot melt adhesive joint, ultrasonic joint degradation,
hydrokinetic activation of a mechanical retaining device, and the
like. Various detachment mechanisms known in the art are discussed
in U.S. Pat. No. 5,722,989, J. Fitch et al: U.S. Pat. No.
5,108,407, G. Geremia et al., U.S. Pat. No. 5,217,484, M. Marks,
and U.S. Pat. No. 5,423,829, P. Pham, which are hereby incorporated
by reference.
[0063] Upon proper positioning of the space filling device 70
within the aneurysm 71, the device will assume a space filling
folded or convoluted configuration due to the confinement of the
aneurysm cavity, a secondary shape imparted to the device by an
elongated longitudinal member having a secondary shape, or both of
these. As a result of the folded or convoluted configuration of the
space filling device, contact points 78 as shown in the enlarged
view of FIG. 18A will result. Upon transmutations of the
transmutable material of the device 70, contact points 78
cross-link, bond, self adhere or the like to become attachment
points which result in a more stable and rigid transmuted space
filling device than would result without such attachment points.
Such a configuration resists compaction and repositioning after
deployment, and facilitates use in aneurysms or other bodily
cavities having a dome to neck ratio of less than 2 to 1. It is
believed that upon proper deployment of the space filling device of
the present invention, flow of blood throughout the aneurysm will
be sufficiently reduced for a sufficient time to allow clot
formation within the aneurysm cavity. Eventually, the clot will
organize and endothelial growth over the clot in the neck area of
the filled aneurysm will ensue, completing the healing process. The
resistance to compaction and reforming by the space filling device
of the present invention is believed to facilitate the reduction of
blood flow throughout the aneurysm for a sufficient time for this
healing process to occur.
[0064] As shown in FIG. 19, a blocking balloon 86 may be deployed
adjacent the neck of aneurysm 87 and distal end 74 of the
microcatheter 73 prior to distally advancing the space filling
device from the distal end of the microcatheter into the aneurysm.
The blocking balloon 86 facilitates maintaining the space filling
device 70 within the aneurysm 71 prior to transmutation of the
transmutable material within the space filling device. In this way,
aneurysms having a greater neck to dome ratio can be effectively
treated.
[0065] FIG. 20 shows a distal end 90 of a delivery system 91
detachably secured to a first end 92 of a space filling device 93
having features of the invention. The distal end 90 of the delivery
system has an elongate tubular shaft 94 with an inner lumen 95
disposed therein. A detachment signal conduit 96 is disposed within
the inner lumen 95 of the shaft and is connected to a degradable
polymer link 97 at a distal extremity 98 of the conduit. A first
end 101 of an elongate longitudinal member 102 is detachably
secured to the degradable polymer link 97 to form a detachment
mechanism 103. The detachment mechanism 103 can be activated by
means of a signal transmitted through the detachment signal conduit
96 which degrades the polymer link and releases the space filling
device 93 from the delivery system 91. The polymer link 97 is
preferably degraded by a chain cleavage or scission reaction.
Materials and methods suitable for such a mechanism are discussed
generally in U.S. Pat. No. 5,443,495 which has been incorporated
herein. The detachment signal transmitted through the detachment
signal conduit 96 is preferably a radiofrequency signal that
initiates a chain cleavage reaction in the degradable polymer link
97, however, other signals or energy delivery may be used such as
alternating or direct electric current, ultrasonic energy, laser
energy or any other form of electromagnetic radiation or the like.
The detachment signal conduit 96 may be a single, double or
multiple pole wire, coaxial cable, fiber optic, elongate ultrasonic
energy transmitter, such as a solid rod of metal, glass or
composite or the like. If a single pole wire is used, a current
flow path may be established by the application of a conductive pad
to a suitable portion of the patient's body, preferably with a
highly conductive gel between the conductive pad and the patient's
skin. Alternatively, a conductive needle, such as a stainless steel
18 gauge needle, may be inserted into a suitable site of the
patient to act as a ground. These grounding techniques may be used
for any port of the invention requiring an electric current flow
path, including the heating of elongated longitudinal or helical
members for transmutation of transmutable materials.
[0066] FIG. 21 shows a distal end 107 of a delivery system 108
detachably secured to a first end 109 of a space filling device 111
having features of the invention. The distal end 107 of the
delivery system 108 has an elongate tubular shaft 112 with an inner
lumen 113 disposed therein. A detachment signal conduit 114 is
disposed within the inner lumen 113 of the shaft 112 and is
connected to a degradable polymer link 115 at a distal extremity
116 of the conduit. The first end 109 of the space filling device
111 is detachably secured to the degradable polymer link 115 to
form a detachment mechanism 118. The detachment mechanism 118 can
be activated by means of a signal transmitted through the
detachment signal conduit 114 which degrades the polymer link 115
and releases the space filling device 111 from the delivery system
108. The detachment signal transmitted through the detachment
signal conduit 114 is preferably a low voltage direct current
electric signal that heats a resistive element 119 and initiates a
chain cleavage reaction in the degradable polymer link 115.
However, other signals or energy delivery may be used such as
alternating or direct electric current, ultrasonic energy, laser
energy or any other form of electromagnetic radiation or the like.
The detachment signal conduit 114 may be a single, double or
multiple pole wire, coaxial cable, fiber optic, elongate ultrasonic
energy transmitter, such as a solid rod of metal, glass or
composite or the like.
[0067] FIG. 22 shows a distal end 121 of a delivery system 122
detachably secured to a first end 123 of a space filling device 124
having features of the invention. The distal end 121 of the
delivery system has an elongate tubular shaft 125 with an inner
lumen 126 disposed therein. A detachment signal conduit 127 is
disposed within the inner lumen 126 of the shaft 125 and is
connected to a mechanical capture device 128 at a distal extremity
129 of the conduit. A first extremity 131 of an elongate
longitudinal member 132 has an enlarged portion 133 which is
mechanically captured by a plurality of capture elements 135 of the
mechanical capture device 128. The capture elements 135 can be
activated by means of a signal transmitted through the detachment
signal conduit 127 which causes the capture elements 135 to expand
in an outward radial direction which releases the enlarged portion
133 of the elongated longitudinal member 132 and releases the space
filling device 124 from the delivery system 122. The detachment
signal transmitted through the detachment signal conduit is
preferably a low voltage electrical signal that heats the capture
elements 135 which are made of a shape memory alloy such as NiTi
and which are configured to have a remembered shape in an open
expanded position which results upon heating of the elements. A
similar result can be achieved in an alternative embodiment of a
mechanical capture device which has capture elements which are
radially constrained by an elongated tubular detachment signal
conduit. Upon longitudinal retraction of the tubular conduit, the
constraint of the capture elements is removed and an enlarged
portion released. Alternative detachment signals include
alternating or direct electric current, ultrasonic energy, laser
energy or any other form of electromagnetic radiation or the like.
The detachment signal conduit may be a single, double or multiple
pole electrically conducting wire, coaxial cable, fiber optic,
elongate tubular member with an inner lumen for conduction of
hydrokinetic energy and activation of a hydrokinetic detachment
mechanism, elongate ultrasonic energy transmitter, such as a solid
rod of metal, glass or composite or the like. The detachment signal
may also be in the form of mechanical actuation by longitudinal or
rotational translation of a mechanical detachment signal conduit
such as an elongate rod, shaft, or tubular member.
[0068] FIG. 23 shows a distal end 138 of a delivery system 139
detachably secured to a first end 141 of a space filling device 142
having features of the invention. The distal end 138 of the
delivery system has an elongate tubular shaft 143 with an inner
lumen 144 disposed therein. A detachment signal conduit 145 is
disposed within the inner lumen 144 of the shaft 143 and is
connected to a mechanical capture device 146 at a distal extremity
147 of the conduit. A first extremity 148 of an elongate
longitudinal member 149 has an enlarged portion 151 which is
mechanically captured by a helical capture element 152 of the
mechanical capture device 146. The helical capture element 152 can
be activated by means of a signal transmitted through the
detachment signal conduit 145 which causes the capture element 152
to expand in an outward radial direction which releases the
enlarged portion 151 of the elongated longitudinal member 149 and
releases the space filling device 142 from the delivery system 139.
The detachment signal transmitted through the detachment signal
conduit 145 is preferably a low voltage electrical signal that
heats the capture element 152 which is made of a shape memory alloy
such as NiTi and which is configured to have a remembered shape in
an open expanded position which results upon heating of the
element. Alternative detachment signals include alternating or
direct electric current, ultrasonic energy, laser energy or any
other form of electromagnetic radiation or the like. The detachment
signal conduit 145 may be a single, double or multiple pole wire,
coaxial cable, fiber optic, elongate ultrasonic energy transmitter,
such as a solid rod of metal, glass or composite or the like.
[0069] An alternative capture element for the mechanical capture
device could include a tubular member, preferably in the form of a
braided capture element 160 as shown in FIGS. 24-26. The braided
capture element 160 as shown is constructed of braided elongated
filaments 161 of a shape memory alloy, such as NiTi alloy. The
capture element 160 could also be a tubular member of shape memory
polymer with similar properties. The elongated filaments 161 are
arranged in a braided tubular structure with a first inner diameter
162 which is smaller than a nominal diameter or transverse
dimension of an enlarged potion 163, and which mechanically
surrounds and captures the enlarged portion. The braided tubular
structure of the capture element also has a second remembered inner
diameter 171 or transverse dimension which is greater than the
transverse dimension of the enlarged portion 163. In this way, the
space filling device 164 can be introduced into a desired area of a
patient while secured to a distal end 165 of a delivery system 166
by the mechanical pressure of the first inner diameter 162 of the
braided capture element 160 on the enlarged portion 163 of the
first end 166 of the elongated longitudinal member 167 of the space
filling device 168. Upon placement of the space filling device 168
within the desired area within a patient, the shape memory
elongated filaments 161 can be activated so as to remember the
larger second inner diameter 171 releasing the enlarged portion and
the space filling device into the desired area of the patient as
indicated by arrow 172. Activation of the braided capture element
160 could be carried out by the application of energy by the
various methods described above. Such an embodiment of the capture
element, as well as any other embodiment of the capture element
discussed above, could be used to detach any of the various
embodiments of the space filling device discussed herein.
[0070] While particular forms of the invention have been
illustrated and described, it will be apparent that various
modifications can be made without departing from the spirit and
scope of the invention. Accordingly, it is not intended that the
invention be limited, except as by the appended claims.
* * * * *