U.S. patent application number 11/934603 was filed with the patent office on 2008-03-06 for method and system for delivering an implant utilizing a lumen reducing member.
This patent application is currently assigned to BOSTON SCIENTIFIC SCIMED, INC.. Invention is credited to Michael P. Wallace.
Application Number | 20080058724 11/934603 |
Document ID | / |
Family ID | 34080545 |
Filed Date | 2008-03-06 |
United States Patent
Application |
20080058724 |
Kind Code |
A1 |
Wallace; Michael P. |
March 6, 2008 |
METHOD AND SYSTEM FOR DELIVERING AN IMPLANT UTILIZING A LUMEN
REDUCING MEMBER
Abstract
Method and system for inserting an implant, such as
vaso-occlusive device, an embolic containment device, or a stent
into a vascular space to a vascular site in a body utilizing a
lumen-reducing catheter. The method and system can be used to treat
aneurysm, tumors and other vascular malformations. A guide is
inserted into the vascular space. First and second catheters are
inserted into the vascular space along the guide. The first or
delivery catheter defines a first cavity, and the second or
lumen-reducing catheter defines a second, smaller cavity. The
second catheter is inserted within the first catheter. In one
embodiment, an implant is advanced together with the first and
second catheters to a vascular site. In an alternative embodiment,
after the first and second catheters are positioned, the guide and
the second catheter are removed from the first cavity, and an
implant is inserted through the first cavity. With these
configurations, radial movement of the guide is restricted to the
smaller, second cavity rather than the larger, first cavity.
Inventors: |
Wallace; Michael P.;
(Pleasanton, CA) |
Correspondence
Address: |
VISTA IP LAW GROUP LLP
12930 Saratoga Avenue
Suite D-2
Saratoga
CA
95070
US
|
Assignee: |
BOSTON SCIENTIFIC SCIMED,
INC.
One Scimed Place
Maple Grove
MN
55311
|
Family ID: |
34080545 |
Appl. No.: |
11/934603 |
Filed: |
November 2, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10627024 |
Jul 25, 2003 |
7309345 |
|
|
11934603 |
Nov 2, 2007 |
|
|
|
Current U.S.
Class: |
604/164.11 |
Current CPC
Class: |
A61B 17/12109 20130101;
A61B 17/12113 20130101; A61B 2017/12063 20130101; A61F 2/966
20130101; A61B 17/12145 20130101; A61B 17/12022 20130101; A61F 2/95
20130101 |
Class at
Publication: |
604/164.11 |
International
Class: |
A61M 25/088 20060101
A61M025/088 |
Claims
1. A method of delivering an implant through a vascular space to a
vascular site in a body, the method comprising: providing a guide,
a displacement member, a first catheter having a body, a distal end
and a proximal end and defining a first cavity, and a second
catheter having a body, a distal end and a proximal end and
defining a second cavity, the second catheter being insertable
within the first cavity; advancing the distal ends of the first and
second catheters together along the guide and through the vascular
space to the vascular site; removing the second catheter and the
guide from the first cavity; inserting the implant into the first
cavity of the first catheter; and advancing the implant through the
first cavity to the vascular site using the displacement
member.
2. The method of claim 1, the second catheter reducing radial
movement of the first catheter relative to the guide.
3. The method of claim 1, the guide being confined to the second
cavity when the first and second catheters are inserted through the
vascular space.
4. The method of claim 1, advancing the distal ends of the first
and second members comprising advancing generally aligned distal
ends of the first and second members along the guide and through
the vascular space to the vascular site.
5. The method of claim 1, wherein the first member is a catheter,
and the second member is a catheter.
6. The method of claim 1, wherein the implant is a vaso-occlusive
implant.
7. The method of claim 1, wherein the displacement member is a
pusher wire.
8. A method of delivering a first implant and a second implant
through a vascular space to a vascular site in a body, the method
comprising: providing a guide, a first catheter having a body, a
distal end and a proximal end and defining a first cavity, and a
second catheter having a body, a distal end and a proximal end and
defining a second cavity, the second catheter being insertable
within the first cavity; providing a first implant and a second
implant, each implant being configured for advancement through the
vascular space; advancing the distal ends of the first and second
catheters together along the guide and through the vascular space
to the vascular site; delivering the first and second implants to
the vascular site, the first implant comprising a containment
implant that reduces a width of a neck of the vascular site; and
retaining the second implant in the vascular site using the first
implant.
9. The method of claim 8, the second catheter reducing radial
movement of the first catheter relative to the guide.
10. The method of claim 8, the guide being confined to the second
cavity when the first and second catheters are inserted through the
vascular space.
11. The method of claim 8, advancing the distal ends of the first
and second members comprising advancing generally aligned distal
ends of the first and second members along the guide and through
the vascular space to the vascular site.
12. The method of claim 8, wherein the first member is a catheter,
and the second member is a catheter.
13. The method of claim 8, wherein the second implant is a
vaso-occlusive implant and the vascular site is an aneurysm, the
containment implant reduces a width of a neck of an aneurysm, and
the vaso-occlusive implant is delivered to the aneurysm and secured
or retained within the aneurysm by the previously deployed
containment implant.
14. A system for delivering an implant through a vascular space to
a vascular site in a body, comprising: a guide; a displacement
member; a first catheter having a body, a distal end and a proximal
end and defining a first cavity; and a second catheter having a
body, a distal end and a proximal end and defining a second cavity,
the second catheter being insertable within the first cavity, the
guide being configured for insertion through the vascular space to
the vascular site, the distal ends of the first and second
catheters being configured for advancement together along the guide
and through the vascular space to the vascular site, and the
displacement member being configured for advancement of the implant
through the first cavity and to the vascular site after the guide
and the second catheter are removed.
15. The system of claim 14, the second catheter reducing radial
movement of the first catheter relative to the guide.
16. The system of claim 14, the guide being confined to the second
cavity when the first and second catheters are inserted through the
vascular space.
17. The system of claim 14, wherein the distal ends of the first
and second members are generally aligned.
18. The system of claim 14, wherein the first member is a catheter,
and the second member is a catheter.
19. The system of claim 14, wherein the implant is a vaso-occlusive
implant.
20. The system of claim 14, wherein the displacement member is a
pusher wire.
21. A system for delivering a first implant and a second implant
through a vascular space to a vascular site in a body, comprising:
a guide; a first catheter having a body, a distal end and a
proximal end and defining a first cavity; a second catheter having
a body, a distal end and a proximal end and defining a second
cavity, the second catheter being insertable within the first
cavity; a first implant, the first implant comprising a containment
implant; and a second implant, the distal ends of the first and
second catheters being configured for advancement together along
the guide and through the vascular space to the vascular site, the
first and second implants being configured for advancement to the
vascular site using the first and second catheters, and the first
implant being positionable to reduce a width of a neck of the
vascular site and to retain the second implant in the vascular
site.
22. The system of claim 21, the second catheter configured for
reducing radial movement of the first catheter relative to the
guide.
23. The system of claim 21, wherein the first member is a catheter,
and the second member is a catheter.
24. The system of claim 21, wherein the distal ends of the first
and second members are generally aligned.
25. The system of claim 21, wherein the second implant is a
vaso-occlusive implant and the vascular site is an aneurysm, the
containment implant reduces a width of a neck of an aneurysm, and
the vaso-occlusive implant is delivered to the aneurysm and secured
or retained within the aneurysm by the previously deployed
containment implant.
Description
RELATED APPLICATION DATA
[0001] This application is a continuation application of co-pending
U.S. patent application Ser. No. 10/627,024, filed Jul. 25, 2003,
the priority of which is claimed under 35 U.S.C. .sctn.120, and the
contents of which are incorporated herein by reference as though
set forth in full.
FIELD OF THE INVENTION
[0002] The field of the invention relates to implantable devices,
and more particularly, to a method and system for inserting a
delivery sheath or catheter through a vascular body using a
lumen-reducing catheter and delivering an implantable device
through the delivery catheter or the lumen-reducing catheter.
BACKGROUND
[0003] In many clinical situations, blood vessels are occluded with
various implants to control bleeding, prevent blood supply to
tumors, block blood flow within an aneurysm or other vascular
malformations. Intracranial aneurysms, for example, may rupture
causing significant bleeding. The significant bleeding may
permanently damage the surrounding brain tissue, possibly causing
serious injury and death. Intracranial aneurysms may be
particularly difficult to access and treat when they are formed in
remote cerebral blood vessels. If left untreated, hemodynamic
forces of normal pulsatile blood flow can rupture fragile tissue in
the area of the aneurysm causing a stroke.
[0004] Various implants have been used to occlude vascular sites.
For example, vaso-occlusive devices are surgical implants that are
delivered through a catheter in a blood vessel or vascular cavity
and placed within aneurysm to form a thrombus and occlude the
aneurysm. In one conventional system, a guide wire is inserted
through a vascular cavity. An outer catheter or sheath is guided by
the wire and inserted through the vascular cavity, and the implant
is pushed or otherwise forced through the interior of the catheter
to an aneurysm site.
[0005] Conventional implant delivery systems, however may exhibit a
number of problems as a result of a gap between the guide wire and
the outer sheath. First, while the guide wire may be able to turn
and maneuver through curved vascular cavities or cavity divisions,
such as a "Y" section or other division that splits a blood vessel,
the outer sheath that follows the guide wire may not be able to
complete these maneuvers. For example, if a blood vessel makes a
sharp turn, the outer portions of the distal end of the sheath may
abut against a vessel section or scrape against the inner vessel
walls as the sheath attempts to follow the guide wire through sharp
turns. As a result, the outer sheath can weaken or damage the blood
vessel or release embolic debris or plaque further down the
bloodstream. Second, the applications and treatments using
conventional sheaths may be limited since it may not be possible to
insert the sheath through narrow or curved vascular cavity sections
to an aneurysm site. Consequently, the aneurysm or containment site
can be left untreated or can be treated while causing damage to
other blood vessel sections, in the process possibly leading to
more serious injury, stroke and death. These problems are amplified
with smaller vessels and vessels having sharp turns and when larger
implants are utilized. Third, implants may not be properly retained
within an aneurysm as a result of the width or the aneurysm neck.
For example, an implant may be improperly secured or inadvertently
released from the aneurysm as a result of slipping through a wide
aneurysm neck.
[0006] A need, therefore, exists for a method and system that
permits a delivery sheath and an implant, such as a vaso-occlusive
implant or an embolic containment implant that facilitates delivery
of a vaso-occlusive implant, to be maneuvered through various
vascular spaces so that the implant is deployed at the proper
location, such as an aneurysm, tumor, while reducing or minimizing
damage to the vascular space and allowing implants to be secured or
retained within the aneurysm.
SUMMARY OF THE INVENTION
[0007] In accordance with one aspect of the present invention is a
method and system for delivering an implant, such as a
vaso-occlusive implant, through a vascular space to a vascular
site. A guide, a first member having a distal end and a proximal
end and defining a first cavity, and a second member having a
distal end and a proximal end and defining a second cavity are
advanced along the guide and through the vascular space to the
vascular site. The second member is inserted through the first
member. When the members are positioned at the site, the second
member and the guide are removed from the first cavity, and an
implant is inserted through the first cavity and delivered to the
vascular site with or without a guide wire.
[0008] The first member can be a first annular catheter defining
the first cavity, and the second member can be a second annular
catheter defining the second cavity. For example, the first annular
catheter has an outer diameter of about 0.66 mm to about 1.3 mm,
the first cavity has a diameter of about 0.5 mm to about 1.25 mm,
the second annular catheter has an outer diameter of about 0.45 mm
to about 1.20 mm, and the second cavity having a diameter of about
0.35 mm to about 1.0 mm.
[0009] With this configuration, the second member reduces radial
movement of the first member relative to the guide, and the guide
is confined to the second cavity when the first and second members
are inserted through the vascular space. Further, the distal ends
of the first and second members can be generally aligned when the
are advanced along the guide.
[0010] In further accordance with the present invention is a method
and system for delivering a first implant through a vascular space
to a vascular site in a body. A first member has a distal end and a
proximal end and defines a first cavity. A second member has a
distal end and a proximal end and defines a second cavity. The
second member is insertable within the first cavity. The distal
ends of the first and second members are advanced along a guide and
through the vascular space to the vascular site, thereby advancing
the first implant to the vascular site.
[0011] The first implant can be advanced by the distal end of the
first member, the distal end of the second member, or the distal
ends of both members. Further, the distal ends of the first and
second members can be generally aligned when they are advanced
along the guide.
[0012] A second implant, such as a vaso-occlusive implant, can also
be inserted through the second cavity of the second member into the
vascular site. The second implant is contained within the vascular
site by the first implant.
[0013] The second member reduces the radial movement of the first
member relative to the guide, and the guide is confined to the
second cavity when the first and second members are inserted
through the vascular space.
[0014] The first member can be a first annular catheter defining
the first cavity, and the second member can be a second annular
catheter defining the second cavity. For example, the first annular
catheter has an outer diameter of about 0.66 mm to about 1.3 mm,
the first cavity has a diameter of about 0.5 mm to about 1.25 mm,
the second annular catheter has an outer diameter of about 0.45 mm
to about 1.20 mm, and the second cavity having a diameter of about
0.35 mm to about 1.0 mm.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Referring now to the drawings in which like reference
numbers represent corresponding parts throughout:
[0016] FIG. 1A is a front view and FIG. 1B is a partial
cross-sectional view of a system having a cavity-reducing or
lumen-reducing sheath according to the present invention;
[0017] FIGS. 2A-J are partial cross-sectional views showing the
manner in which an implant is inserted through a vascular space to
a vascular site using an outer or delivery sheath, a lumen reducing
sheath and guide wire; and
[0018] FIGS. 3A-F show how an embolic containment implant is
delivered to a neck of an aneurysm and a second implant is then
inserted into and retained within an aneurysm using a system and a
method according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] Referring to FIGS. 1A-B, a system or assembly 100 of the
present invention includes a first or delivery member 110, such as
an outer, annular catheter or sheath, a second or reducing member
120, such as an inner, annular catheter or sheath, and a guide 130,
such as a guide wire. The system 100 is used to deliver an implant
(not shown) through a vascular space to a vascular site, such as an
aneurysm, tumor, a site for capturing embolic debris, or other
vascular malformation (generally vascular site).
[0020] The present invention is suitable for delivering or
advancing various devices or implants into the body of a patient
for different applications. For example, the present invention can
be used to deliver a vaso-occlusive implant, such as a coil and a
liquid, to treat or occlude an aneurysm. Further, the present
invention can be used to deliver an embolic containment implant
which facilitates delivery of a vaso-occlusive implant by, for
example, reducing the size of the aperture formed by a neck of an
aneurysm to contain the vaso-occlusive device in the aneurysm
without risk of embolic migration. Typically, an embolic
containment implant would be positioned slightly inside the neck of
the aneurysm. Additionally, the present invention can be used to
deliver a stent to ensure that a vessel remains open or unblocked.
The stent can also be used to help contain subsequent delivery of
embolic materials (liquids, coils) into the aneurysm, similar to an
embolic containment implant. Unlike the embolic containment system,
however, the stent is placed outside the neck of the aneurysm or
into the parent vessel. An "implant" in this specification refers
to the various types of implants that can be delivered with the
present invention.
[0021] Persons of ordinary skill in the art will recognize that the
implant can be delivered into the body through various entry
points, e.g., percutaneously through a peripheral vessel, such as a
femoral, carotid, or radial artery, or other vein, artery or
vascular space, to treat various vascular sites. The present
invention can be used to treat humans and animals. This
specification, however, describes and illustrates a system and
method related to treating a vascular cranial aneurysm sites with
various implants for purposes of explanation and illustration, but
the invention is not so limited.
[0022] Various guides 130 can be used with the system 100 of the
present invention. One exemplary guide is a guide wire, such as a
1014 to GC18 guide wire, having diameters from about 0.01'' to
about 0.018''. The guide wire can also have a rounded or modified
tip, such as a "J hook" or a smoothed or rounded tip that allows
the guide wire to be inserted through a vascular space more
smoothly. Other exemplary guides include a guiding catheter or
other guide rail. The particular guide 130 that is utilized may
depend on the particular application. Thus, the invention is not
limited to using a particular guide 130, but this specification
refers to and illustrates a guide wire for purposes of explanation
and illustration.
[0023] The outer, first or delivery catheter or sheath ("delivery
catheter 110") may be a micro-catheter or other elongated delivery
device. The size of the delivery catheter 110 can vary depending on
the particular patient, treatment, and implant to be delivered to
the aneurysm site. For example, when accessing a brain aneurysm in
a small vessel, an appropriately sized delivery catheter 110 can be
quite small and flexible.
[0024] Exemplary delivery catheters 110 for treating cranial
aneurisms are 3.0 F to 3.8 F catheters having an outer diameter
(OD) 112 from about 1.0 mm to about 1.3 mm. The inner diameter (ID)
114 of the lumen or cavity 116 of the delivery catheter 110 can be
from about 0.8 mm to about 1.1 mm. Different delivery catheters 110
with different IDs 114 and ODs 112 can be utilized depending on the
particular application and size of the implant. The ID 114 of the
delivery catheter 110, however, should be made large enough to
accommodate a second or cavity-reducing or lumen-reducing catheter
("reducing catheter 120") and the implant.
[0025] The delivery catheter 110 can be made of different materials
and have various coating to facilitate insertion through a vascular
space. Exemplary delivery catheter 110 materials include
Polypropylene, PE, Urethanes, Nylons, and Pebax. One exemplary
coating applied to the outer surface of the delivery catheter 110
is a hydrophilic coating. Persons of ordinary skill in the art will
recognize that various delivery catheter 110 sizes, materials, and
coatings can be utilized depending on the particular application
and treatment.
[0026] The second or reducing catheter 120 is inserted within the
cavity or lumen 116 defined by the delivery catheter 110. The Outer
Diameter (OD) 122 of the reducing catheter 120 should be smaller
than the ID 114 of the delivery catheter 110 so that the reducing
catheter 120 can be inserted through the lumen 116 of the delivery
catheter 110. For example, if the delivery catheter 110 defines a
lumen 116 with an ID 114 from about 0.5 mm to about 0.8 mm, then
the OD 122 of the reducing catheter 120 can be from about 0.66 mm
to about 1.0 mm. In one embodiment, the delivery catheter 110
defines a cavity having an ID 114 of about 0.033'', and the
reducing catheter 120 defines a reduced cavity or lumen 126 having
an ID 124 from about 0.012'' to about 0.021''. As a result, with
the reducing catheter 120, movement of the guide wire 130 is
restricted to a smaller cavity or lumen compared to a larger lumen
or cavity of a conventional delivery catheter. Similarly, with the
reducing catheter 120, movement of the system 100 around the guide
wire 130 is restricted to the smaller or lumen cavity 126, rather
than a larger cavity of an outer catheter 110.
[0027] Thus, radial movement (e.g., up-down, side-to-side) of the
assembly 110 including the delivery and reducing catheters 110 and
120 is limited compared to conventional systems, while allowing for
the catheters to be inserted into a vascular space. With these
exemplary configurations, the amount of movement or play between
the guide wire 130 and the delivery catheter 110 is reduced so that
the delivery catheter 110 can be inserted through a vascular space
more easily and efficiently. For example, in one embodiment, the
area of the first lumen 120 is reduced by about 35% to about 75%.
Persons of ordinary skill in the art will recognize that different
sizes and thickness of the catheters 110 and 120 can produce
reduced cavities 126 of different sizes. Further, the gap between
the catheters 110 and 120 can be adjusted as needed.
[0028] In use, the delivery and reducing catheters 110 and 120 are
positioned in a vessel so that the distal ends 118 and 128 of the
catheters 110 and 120 are advanced over or otherwise in conjunction
with a guide wire 130 to a vascular site. For example, the distal
ends 118 and 128 of the delivery and reducing catheters 110 and 120
may be generally aligned with each other when being advanced
through the vascular space over the guide wire 130. The
lumen-reducing catheter 120 can also extend somewhat ahead of the
delivery catheter 110 if necessary.
[0029] If a vaso-occlusive implant is being delivered to an
aneurysm site, the reducing catheter 120 and the guide wire 130 are
removed after they are properly positioned at the vascular site. A
displacement member, such as a pusher wire, advances the implant
through the delivery catheter 110. Various other displacement
members can be utilized, such as a plunger that is attached to the
guide wire 130 to advance the implant or fluid pressure through the
delivery catheter 110. When vaso-occlusive implants 230 are placed
within or at a neck an aneurysm 220, they tend to induce the
formation of fibrin network (clot or thrombus). The thrombus
provides a high-surface-area substrate on which the cells
responsible for wound healing (such as fibroblasts) migrate and
proliferate as they deposit collagen to replace the clot with more
stable collagenous fibrous tissue.
[0030] In cases involving a first implant being delivered to an
aneurysm site to retain or contain a second implant within an
aneurysm site, the containment implant is inserted through a vessel
together with the delivery and lumen-reducing catheters to a neck
of the aneurysm. The containment implant reduces the width of a
neck of an aneurysm. A second implant, such as a vaso-occlusive
implant, is delivered through the reducing catheter to the aneurysm
site and is secured or retained within the aneurysm by the
previously deployed containment implant.
[0031] Having described components of a system 100 according to the
present invention and the different manners in which they can be
used, FIGS. 2A-I illustrate a method 200 and components of the
system 100 at different stages showing in further detail how the
system 100 is used to advance an implant, such as a stent, a coil,
a filter or an implant that removes part of a vessel clot, to an
aneurysm site.
[0032] Initially, referring to FIG. 2A, the guide wire 130 is
inserted and fed through a vascular cavity or space 210. The
delivery catheter 110 and the reducing catheter 120 are advanced
over the guide wire 130. For example, as previously discussed, the
delivery and lumen-reducing catheters 110 and 120 can be advanced
together over the guide wire 130, and the catheters 110 and 120 can
be generally aligned with each other as they are advanced over the
guide wire 130. The reducing catheter 120 can also extend somewhat
ahead of the delivery catheter if necessary.
[0033] As the catheters 110 and 120 are advanced through the
vascular space 210, as shown in FIG. 2B, the distal ends 118 and
128 of the delivery and reducing catheters 110 and 120 are
positioned at or near the vascular site 220 (shown generally as a
dotted line.) The site 220 is then said to be catheterized.
Referring to FIG. 2C, the reducing catheter 120 and the guide wire
130 are retracted from the site 220 after the outer catheter 110 is
positioned and, as shown in FIG. 2D, removed or pulled from the
cavity 116 of the delivery catheter 110. As a result, only the
delivery catheter 110 remains inserted within the vascular cavity
210 at the vascular site 220, and the lumen 116 of the delivery
catheter 110 is empty.
[0034] Referring to FIG. 2E, the guide wire 130 is re-inserted (or
a different guide wire is inserted) into the lumen or cavity 116 of
the delivery catheter 110. An implant 230, such as a vaso-occlusive
coil, a stent, a filter, or an implant that removes part of a
vessel clot is inserted into the proximate end 119 of the delivery
catheter 110. An insertion or displacement device 240 advances the
implant 230 along the guide wire 130 and through the cavity 116 of
the delivery catheter 110 until the implant 230 exits or reaches
the distal end 118 of the outer catheter 110, as shown in FIG. 2F.
In an alternative embodiment, the implant 230 is pushed by the
displacement device 240 through the cavity 116 of the delivery
catheter 110 without a guide wire 130, however, a guide wire that
directs the implant 230 to the site 220 is shown for purposes of
illustration.
[0035] Referring to FIG. 2G, the displacement device 240 is
detached or released from the implant 230 (if necessary), and the
displacement device 240 and the guide wire 130 are removed from the
lumen 116 of the delivery catheter 110. As a result, as shown in
FIG. 2H, the implant 230 remains at the vascular site 220. As shown
in FIG. 2I, the delivery catheter 110 may be removed from the
vascular space 210, leaving the implant 230 at the site 220. The
implant (e.g., a filter) may later be removed from the vascular
space if necessary.
[0036] FIGS. 3A-F illustrate an alternative embodiment of the
present invention directed to delivering an embolic containment
implant and a second implant, such as a vaso-occlusive implant,
utilizing a lumen-reducing catheter. For example, a containment
implant can be delivered to the aneurysm neck to reduce the width
of the neck, and a vaso-occlusive coil can then be delivered
through the lumen reducing catheter into the aneurysm. As a result,
the containment implant reduces the width of the neck to contain
the coil within the aneurysm and retains the coil in the aneurysm
while reducing the possibility that the coil will be inadvertently
released from the aneurysm through the neck.
[0037] Specifically, referring to FIG. 3A, an embolic containment
device 300, such as containment implants 300a and 300b (generally
300), are advanced together with the delivery and lumen-reducing
catheters 110 and 120 and guided through a vessel 210 by a guide
wire 130. As shown in FIG. 3A, an aneurysm 310 includes a sack or
body 315 and a neck 320 with a width W1. Referring to FIG. 3B, the
delivery system is advanced further through the vessel 210 so that
the containment implants 300 are inserted into the aneurysm neck
320. As shown in FIG. 3C, the containment implants 300 are arranged
so that they are placed within the aneurysm sack 315 and over part
of the neck 320. As a result, the containment device 300 reduces
the original width W1 of the neck 320 to a smaller width W2. The
containment device 300 can expand to fill in the neck 320 and lower
part of the aneurysm 310 in, for example, a disc-like shape or
other shapes, depending on the site to be occluded.
[0038] Referring to FIG. 3D, a vaso-occlusive device 330, such as a
coil, is inserted through the lumen-reducing catheter 120 until, as
shown in FIG. 3E, the distal end 332 of the coil 330 exits the
distal end of the lumen reducing catheter 120 and is inserted into
the sack 315 of the aneurysm 310 through or between the containment
implants 300. In FIG. 3F, the coil 330 is inserted into the
aneurysm sack 315 and retained by the containment implants 300. The
delivery catheter 110, the lumen-reducing catheter 120, and the
guide wire 130 can then be removed from the vessel 210, leaving the
coil 330 and containment implants 300 behind at the aneurysm 310.
The coil 330 can then assist in forming a thrombus to occlude the
aneurysm 310.
[0039] Having described different systems 100 and a methods 200
according to the present invention, persons of ordinary skill in
the art will appreciate that the present invention can be
implemented with various types of guides 130, delivery catheters
110, reducing catheters 120, implants 230, and displacement or
pusher members 240 to deliver the implants 230 through a vascular
cavity 210 to a vascular site 220. The implant can be solely a
vaso-occlusive implant, solely a containment implant that contains
a vaso-occlusive implant, or serve as both a vaso-occlusive and a
containment implant.
[0040] For example, one exemplary vaso-occlusive implant 230 is a
vaso-occlusive coil that occludes the interior or sack of an
aneurysm, such as a Guglielmi Electrolyctically Detachable Coil
(GDC). A coil can assume a linear helical configuration when
stretched and a folded convoluted configuration when relaxed. The
coil has a stretched configuration when placed in the delivery
catheter 110, which is used in placement of the coil at the desired
aneurysm site, and assumes the convoluted configuration when the
coil is ejected from the delivery catheter 110 and the coil
relaxes. Other shapes, such as "flower" shapes, double vortices,
and random shapes can also be used. Vaso-occlusive coils having
more complex, three-dimensional structures in a relaxed
configuration can also be utilized. The coils may be deployed in
the approximate shape of a sphere, an ovoid, a clover, a box-like
structure or other distorted spherical shape. Vaso-occlusive coils
may also be made of various other biocompatible polymers or of
carbon fibers. The vaso-occlusive implant may be covered or
connected with fibrous materials tied to the outside of the coil or
braided onto the outer cover of the coil as desired.
[0041] For occluding peripheral or neural sites, coils will
typically be made of 1 mil to 5 mil diameter wire (e.g., platinum
or platinum/tungsten alloy) that may be wound to have an inner
diameter of 5 mils to 60 mils with a minimum pitch. The outer
diameter is then typically between 0.007 and 0.700 inch. The length
of the coil 230 will normally be in the range of 0.5 to 60 cm,
preferably 0.5 to 40 cm. The coils may also be formed in such a way
that they are essentially linear as they pass through the delivery
catheter 110 and yet assume a randomly oriented relaxed condition
after they are released from the end 118 of the delivery catheter
110.
[0042] A further exemplary implant 230 is a vaso-occlusive implant
that includes an inner core wire covered with a polymer. The
polymeric material includes protein based polymers, absorbable
polymers, non-protein based polymers, and combinations thereof. The
polymer facilitates forming of emboli to occlude a body cavity.
[0043] Other exemplary vaso-occlusive implants 230 include multiple
vaso-occlusive members with electrolytically disintegratible links
between the members. For example, a link may be relatively more
susceptible to electrolysis in an ionic solution such as blood or
most other bodily fluids than is a vaso-occlusive member. The link
may also be tapered or otherwise modified, or coated with an
insulative polymer and scored to limit the area of electrolytic
disintegration of the link to a more discrete region or point.
[0044] The implant 230 can also have a fibrous structure carried by
the core member. One exemplary fibrous structure includes one or
more nano-scale fibers or nanofibers having diameters ranging from,
for example, 50 to 10000 nm. The nanofibers may provide or enhance
thrombogenic properties of the vaso-occlusive device. The core
member is preferably made of a biodegradable material.
Biodegradable or absorbable materials suitable for the core member
may include, but are not limited to, synthetic polymers,
polysaccharides, and proteins. Suitable polymers may include, for
example, polyglycolic acid, polylactic acid, polycaprolactone,
polyhydroxybutyrate, polyhydroxyvalerate, polydioxanone,
polycarbonates, polyanhydrides, polyhydroxyalkanoates,
polyarylates, polysaccharides, polyamino acids, and copolymers
thereof. In addition or alternatively, proteins may be used, such
as collagen, elastin, fibrin, fibrinogen, fibronectin, vitronectin,
laminin, silk, and/or gelatin. In addition or alternatively,
polysaccharides may be used, such as chitin, chitosan, cellulose,
alginate, hyaluronic acid, and chondroitin sulfate. Many of these
materials are commercially available. Fibrin-containing
compositions are commercially available, for example from Baxter.
Collagen-containing compositions are commercially available, for
example, from Cohesion Technologies, Inc., of Palo Alto, Calif.
Absorbable materials may be used alone or in any combination with
each other. The absorbable material may also be a mono-filament or
multi-filament strands.
[0045] The implant 230 can also be a device that disrupts an
endothelium of a well of the aneurysm in this matter reduces the
risk of the aneurysm wall expanding, thinning and/or rupturing.
[0046] As discussed in connection with FIGS. 3A-J, a further
exemplary implant 230 is an embolic containment device. The embolic
containment device is used to contain or secure a second implant,
such as a vaso-occlusive implant, within an aneurysm by reducing
the size of the aneurysm neck. One exemplary embolic containment
device expands or opens in a "disc" like shape to fill the lower
portion of the aneurysm sack, the neck of the aneurysm. The device
can also extend down into the blood vessel to capture embolic
debris. Exemplary embolic containment implant materials include,
but are not limited to, braided polyester, nanofibers, and various
mesh materials. In addition to containing a vaso-occlusive device
within an aneurysm, the embolic containment device can also assist
with healing the aneurysm since it serves as a scaffold across the
aneurysm neck, thereby reducing blood flow and facilitating
clotting.
[0047] A further exemplary implant 230 is a stent. A stent can
serve as an embolic containment implant or a vaso-occlusive
implant. For example, a stent can be used to reduce the size of the
aneurysm neck, and a vaso-occlusive coil is inserted between stent
sections into an aneurysm. A stent can also be covered or coated
with materials that facilitate clotting so that the stent can be
inserted into the aneurysm and occlude the aneurysm. For example,
with reference to the embodiment shown in FIGS. 2A-J, a
self-expanding stent can be attached to the distal end of the
pusher member 240 as they are advanced through the outer catheter
110 and then be released upon reaching the aneurysm site.
[0048] One type of stent that can be delivered with the present
invention is a self expanding stent, e.g., a NiTi self expanding
stent. A balloon expandable stent, such as a polymer or stainless
steel expandable stent, can also be utilized. Other exemplary
stents include coated or non-coated stents, covered or partially
covered stents, high density braid stents, and stents covered
in-situ.
[0049] Other implants suitable for use with the present invention
include blood filters and clot grabbers or implants that secure a
segment of a clot in a vessel. These implants, however, may be
removed from the vessel instead of being detached or released into
an aneurysm or vascular site.
[0050] Further, persons of ordinary skill in the art will recognize
that various implants 230 may be coated or mixed with radiopaque
materials for fluoroscopy tracking through the vascular space 210.
Exemplary radiopaque materials include, but are not limited to,
metals (e.g. tantalum, gold, silver, tungsten, rhenium, palladium,
rhodium, or platinum), barium sulfate, bismuth oxide, bismuth
subcarbonate, and the like. One exemplary coating is a
platinum/tungsten alloy, e.g., 8% tungsten and the remainder
platinum. These metals have significant radiopacity and in their
alloys may be tailored to accomplish an appropriate blend of
flexibility and stiffness. They are also largely biocompatible.
Certain polymers are also suitable as vaso-occlusive member
material either alone or in conjunction with metallic markers to
provide radiopacity. These materials are chosen so that the
procedure of locating the vaso-occlusive member within the vessel
may be viewed using radiography.
[0051] The particular type, design and configuration of an implant
230 that can be delivered with the lumen reducing catheter system
100 of the present invention can be selected based on various
factors, such as the particular application, treatment, and
patient.
[0052] The system and method of the present invention are
advantageous compared to conventional systems since the present
invention allows a delivery catheter to be inserted at a vascular
site more effectively, while reducing or minimizing damage to
surrounding vascular tissue and walls. The gap between the guide
wire and the outer catheter is effectively minimized or reduced
with the reducing catheter, allowing the distal ends of the
delivery and reducing catheters to be maneuvered along the guide
wire through sharper turns, "Y" sections and other divisions in
blood vessels by limiting radial movement of the distal ends of the
assembly. The delivery catheter is less likely to scrape against
vessel walls or impact middle portions of "Y" sections or other
divisions of vascular bodies, while following the guide wire
through sharper turns, curves or blood vessel divisions compared to
conventional systems.
[0053] Further, the present invention allows a vaso-occlusive
implant, such as a coil, to be inserted within an aneurysm and to
be retained in the aneurysm by a containment implant that
effectively reduces the width of a neck of an aneurysm. As a
result, the present invention reduces the likelihood that a coil
will be improperly secured or inadvertently released from the
aneurysm as a result of slipping through a wide aneurysm neck.
[0054] Various types and sizes of implants can then be inserted
through the positioned outer or delivery catheter. Having described
the improved method and system for delivering an implant according
to the present invention, persons of ordinary skill in the art will
recognize that the system and method can be modified in various
ways to reduce the effective diameter or size of a delivery
catheter lumen or cavity. For example, other delivery and reducing
catheters with different sizes and proportions can be utilized.
Further, various types and sizes of implants can be utilized
including vaso-occlusive implants, such as a coil, an embolic
containment device that facilitates delivery of a vaso-occlusive
device, a stent and a filter.
[0055] Further, the present invention can be used to treat
aneurysms, tumors or other vascular malformations. Although
references have been made in the foregoing description to various
embodiments, persons of ordinary skill in the art will recognize
that insubstantial modifications, alterations, and substitutions
can be made to the described embodiments without departing from the
invention as recited in the accompanying claims.
* * * * *