U.S. patent application number 15/284360 was filed with the patent office on 2017-01-26 for devices and methods for treatment of abdominal aortic aneurysm.
This patent application is currently assigned to Thomas J. Fogarty. The applicant listed for this patent is Thomas J. Fogarty. Invention is credited to Steven W. KIM, Brian K. SHIU.
Application Number | 20170020653 15/284360 |
Document ID | / |
Family ID | 32324461 |
Filed Date | 2017-01-26 |
United States Patent
Application |
20170020653 |
Kind Code |
A1 |
KIM; Steven W. ; et
al. |
January 26, 2017 |
DEVICES AND METHODS FOR TREATMENT OF ABDOMINAL AORTIC ANEURYSM
Abstract
Disclosed are devices and methods for treatment of aneurysms. In
one variation, a device for treating an aneurysm includes a tubular
graft comprising a longitudinal channel having a first end and a
second end, wherein the longitudinal channel is bifurcated at a
bifurcated portion. The device also includes an expandable
anchoring member attached to the first end of the longitudinal
channel and inflatable chambers on the exterior of the tubular
graft. The inflatable chambers are configured to receive a filling
medium. At least one of the inflatable chambers is positioned along
the longitudinal channel on the side of the bifurcated portion
toward the expandable anchoring member and is only partially around
the circumference of the longitudinal channel.
Inventors: |
KIM; Steven W.; (Los Altos,
CA) ; SHIU; Brian K.; (Sunnyvale, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Fogarty; Thomas J. |
Mountain View |
CA |
US |
|
|
Assignee: |
Fogarty; Thomas J.
Mountain View
CA
|
Family ID: |
32324461 |
Appl. No.: |
15/284360 |
Filed: |
October 3, 2016 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
14225730 |
Mar 26, 2014 |
|
|
|
15284360 |
|
|
|
|
14087980 |
Nov 22, 2013 |
8936633 |
|
|
14225730 |
|
|
|
|
13663272 |
Oct 29, 2012 |
8647377 |
|
|
14087980 |
|
|
|
|
13533658 |
Jun 26, 2012 |
8535367 |
|
|
13663272 |
|
|
|
|
11552913 |
Oct 25, 2006 |
8231665 |
|
|
13533658 |
|
|
|
|
10301061 |
Nov 20, 2002 |
|
|
|
11552913 |
|
|
|
|
60333373 |
Nov 26, 2001 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 17/12036 20130101;
A61F 2002/823 20130101; A61B 17/12118 20130101; A61B 17/12022
20130101; A61F 2250/0003 20130101; A61F 2/90 20130101; A61B
2017/1205 20130101; A61B 17/12136 20130101; A61F 2/954 20130101;
A61F 2/958 20130101; A61B 2017/3484 20130101; A61F 2002/065
20130101; A61B 2017/00898 20130101; A61B 2017/00986 20130101; A61B
17/1219 20130101; A61F 2/07 20130101; A61F 2002/077 20130101; A61B
17/12195 20130101; A61B 17/12186 20130101 |
International
Class: |
A61F 2/07 20060101
A61F002/07 |
Claims
1. A device for treating an aneurysm, the device comprising: a
tubular graft comprising a longitudinal channel having a first end
and a second end, wherein the longitudinal channel is bifurcated at
a bifurcated portion; an expandable anchoring member attached to
the first end of the longitudinal charm and an inflatable chamber
on the exterior of the tubular graft, wherein the inflatable
chamber is configured to receive a filling medium, and wherein the
inflatable chamber is along the longitudinal channel on the side of
the bifurcated portion toward the expandable anchoring member, and
wherein the inflatable chamber is only partially around the
circumference of the longitudinal channel.
2. The device of claim 1, wherein the inflatable chamber is
configured to hold the tubular graft in place within a blood vessel
of a patient.
3. The device of claim 1, wherein the tubular graft comprises at
least one of polytetrafluoroethylene (PTFE), polyester,
polyurethane, nylon, and silicone.
4. The device of claim 11, wherein the inflatable chamber comprises
at least one of polytetrafluoroethylene (PTFE), polyester,
polyurethane, nylon, and silicone.
5. The device of claim 1, wherein the tubular graft is configured
to be placed across an infra-renal aortic aneurysm.
6. The device of claim 1, wherein the filling medium is a
biocompatible fluid.
7. The device of claim 1, further comprising a chamber access port
and wherein the inflatable chamber is in fluid communication with
the chamber access port.
8. A device for treating an aneurysm, the device comprising: a
tubular graft comprising a longitudinal channel, wherein the
longitudinal channel is bifurcated at a bifurcated portion; a stein
attached to the tubular graft; and a first inflatable chamber on
the exterior of the tubular graft, wherein the first inflatable
chamber is configured to receive a filling medium, and wherein the
first inflatable chamber is only partially around the circumference
of the tubular graft; and a second inflatable chamber on the
exterior of the tubular graft, wherein the second inflatable
chamber is in fluid communication with the first inflatable
chamber.
9. The device of claim 8, wherein the first inflatable chamber is
spaced along a longitudinal direction of the tubular graft from the
second inflatable chamber.
10. The device of claim 8, further comprising a narrowing in
between the first inflatable chamber and the second inflatable
chamber.
11. The device of claim 10, wherein the first inflatable chamber
has a first chamber radius measured from a center point of the
tubular graft to a radially furthest point on an outside surface of
the first inflatable chamber, wherein the second inflatable chamber
has a second chamber radius measured from the center point of the
tubular graft to the radially further point on the outside surface
of the second inflatable chamber, wherein the narrowing has a
narrowing radius measured from the center point of the tubular
graft to a radially furthest point on the outside surface of the
narrowing, and wherein the first chamber radius and the second
chamber radius are greater than the narrowing radius.
12. The device of claim 8, further comprising a chamber access port
and wherein the first inflatable chamber is in fluid communication
with the chamber access port.
13. The device of claim 8, wherein the tubular graft comprises at
least one of polytetrafluoroethylene (PTFE), polyester,
polyurethane, nylon, and silicone.
14. The device of claim 8, wherein the inflatable chamber comprises
at least one of polytetrafluoroethylene (PTFE), polyester,
polyurethane, nylon, and silicone.
15. The device of claim 8, wherein the tubular graft is configured
to be placed across the abdominal aortic aneurysm.
16. A method of treating an abdominal aortic aneurysm, the method
comprising: positioning a tubular graft comprising a longitudinal
channel having a first end and a second end in the abdominal aortic
aneurysm, wherein the longitudinal channel is bifurcated at a
bifurcated portion; securing the tubular graft in place with an
expandable anchoring member attached to the first end of the
longitudinal channel; and inflating an inflatable chamber on the
exterior of the tubular graft using a filling medium, wherein the
inflatable chamber is positioned along the longitudinal channel on
the side of the bifurcated portion toward the expandable anchoring
member and is only partially around the circumference of the
longitudinal channel.
17. The method of claim 16, wherein the tubular graft comprises at
least one of polytetrafluoroethylene (PTFE), polyester,
polyurethane, nylon, and silicone.
18. The method of claim 16, wherein the inflatable chamber
comprises at least one of polytetrafluoroethylene (PTFE),
polyester, polyurethane, nylon, and silicone.
19. The method of claim 16, wherein the filling medium is a
biocompatible fluid.
20. The method of claim 16, further comprising inflating the
inflatable chamber through a chamber access port in fluid
communication with the inside of the inflatable chamber.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. patent
application Ser. No. 14/225,730, filed 26 Mar. 2014, which is a
continuation of U.S. patent application Ser. No. 14/087,980, filed
22 Nov. 2013, now issued U.S. Pat. No. 8,936,633, which is a
continuation of U.S. patent application Ser. No. 13/663,272, filed
29 Oct. 2012, now issued U.S. Pat. No. 8,647,377, which is a
continuation of U.S. patent application Ser. No. 13/533,658, filed
26 Jun. 2012, now issued U.S. Pat. No. 8,535,367, which is a
continuation of U.S. patent application Ser. No. 11/552,913, filed
25 Oct. 2006, now issued U.S. Pat. No. 8,231,665, which is a
continuation of U.S. patent application Ser. No. 10/301,061, filed
20 Nov. 2002, now abandoned, which claims the benefit of U.S.
Provisional Application No. 60/333,373, filed 26 Nov. 2001, all of
which are incorporated herein by reference in their entireties.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to devices and methods for the
treatment of diseases in the vasculature, and more specifically,
devices and methods for treatment of aneurysms found in blood
vessels. Aneurysms can occur in various areas of the cardiovascular
system, but are commonly found in the abdominal aorta, thoracic
aorta, and cerebral vessels. Aneurysms are unusual ballooning of
the vessel due to loss of strength and/or elasticity of the vessel
wall. With the constant pulsating pressure exerted on the vessel
wall, the diseased or weakened wall can expand out and potentially
rupture, which frequently leads to fatality. Prior methods of
treating aneurysms have consisted of invasive surgical techniques.
The technique involves a major cut down to access the vessel, and
the diseased portion of the vessel is replaced by a synthetic
tubular graft. Accordingly, this invasive surgical procedure has
high mortality and morbidity rates.
[0003] Due to the inherent risks and complexities of the surgical
procedures, various attempts have been made to develop minimally
invasive methods to treat these aneurysms. For treatment of
abdominal and thoracic aortic aneurysms, most of the attempts are
catheter-based delivery of an endoluminal synthetic graft with some
metallic structural member integrated into the graft, commonly
called stent-grafts. One of the primary deficiencies of these
systems is durability of these implants. Because catheter-based
delivery creates limitations on size and structure of the implant
that you can deliver to the target site, very thin synthetic grafts
are attached to metallic structures, where constant interaction
between the two with every heartbeat can cause wear on the graft.
Also, the metallic structures often see significant cyclical loads
from the pulsating blood, which can lead to fatigue failure of the
metallic structure. The combination of a thin fragile graft with a
metallic structure without infinite life capabilities can lead to
implant failure and can ultimately lead to a fatality.
[0004] While the above methods have shown some promise with regard
to treating aortic aneurysms with minimally invasive techniques,
there remains a need for a treatment system which doesn't rely on
the less than optimal combination of a thin graft and metallic
structural member to provide long-term positive results. The
present invention describes various embodiments and methods to
address the shortcomings of current minimally invasive devices and
to meet clinical needs.
SUMMARY OF THE INVENTION
[0005] In a first aspect, the present invention provides a two part
prostheses where one part is an expandable sponge structure and the
other part is an expandable tubular mesh structure. The expandable
sponge structure is intended to fill the aneurysm cavity to prevent
further dilatation of the vessel wall by creating a buffer or
barrier between the pressurized pulsating blood flow and the
thinning vessel wall. The expandable tubular meth structure, which
is placed across the aneurysm contacting the inner wall of healthy
vessel proximal and distal to the aneurysm, serves two purposes.
One, it defines the newly formed vessel lumen, even though it does
not by itself provide a fluid barrier between the blood flow and
the aneurysm. Two, it keeps the expandable sponge structure from
protruding out of the aneurysm and into the newly formed vessel
lumen. The expandable tubular mesh structure is delivered first
across the aneurysm. Then, the expandable sponge structure is
delivered via a catheter-based delivery system through a "cell" of
the tubular mesh structure and into the aneurysm sac. When the
sponge structure is deployed into the aneurysm sac and comes in
contact with fluid, it will expand to a size larger than the
largest opening or cell of the tubular mesh structure as to prevent
the sponge structure from getting out of the aneurysm sac. The
filled aneurysm sac will most likely clot off and prevent further
dilation of the aneurysm and subsequent rupture. The blood flow
should maintain a natural lumen where the luminal diameter is
approximately defined by the diameter of the tubular mesh
structure. The advantage of this system is that the sponge filler
material acts like a graft but has unparalleled durability. The
metallic structure can be optimized for durability as well because
the size constraint is somewhat relieved due to the absence of an
integrated graft material, which takes up a significant amount of
space in a catheter.
[0006] In addition, the expandable sponge structure can be used to
repair existing endoluminal stent-grafts which have developed
leaks. There are thousands of endoluminal stein-grafts implanted
into humans to treat abdominal aortic aneurysms. That number is
growing daily. The endoluminal stent-grafts are intended to exclude
the aneurysm from blood flow and blood pressure by placing a
minimally porous graft supported fully or partially by metallic
structural members, typically called stents. The acute success rate
of these devices is very high, but there are a significant number
of these which develop leaks, or blood flow/pressure re-entering
the aneurysm sac after the procedure. If the source of the leak can
be accessed by the delivery system, the expandable sponge structure
can be deployed through that access point.
[0007] In another aspect, the present invention provides an
inflatable tubular balloon graft. It is a tubular graft, straight
or bifurcated, where its wall is not a solid structure but a hollow
chamber. The chamber can be filled with a variety of materials
which can dictate the mechanical properties of the prostheses. The
unfilled tubular balloon graft can be folded and loaded into a
catheter-based delivery system, and once in position the tubular
balloon graft can be "inflated" with the filler material. The
material would be filled in a fluid form and may stay a fluid form
or can be solidified by various means such as UV light, heat, and
time. The advantage of this system is that a metallic structure is
not needed to provide structure to the graft. It is instead
replaced by the injectable fluid within the chamber of the tubular
balloon graft. Customization of the mechanical properties of the
graft is easily accomplished by using balloon fillers of varying
properties.
[0008] The tubular balloon graft can be completely non-porous,
completely porous with same degree of porosity throughout the
graft, completely porous with varying porosity within the graft, or
partially non-porous and partially porous. Significant porosity an
the very outer layer would allow for delivery of an aneurysm sac
filling substance or a drug. Porosity on the ends of the graft will
help promote cellular in-growth. Porosity on the ends can also be
used to deliver an adhesive so that the graft can be securely
attached to the vessel wall.
[0009] Another embodiment of the tubular balloon graft includes a
tubular balloon graft with a bulging outer layer. This will allow
the outer surface of the tubular balloon graft to fill some or all
of the aneurysm. This will provide a primary or secondary barrier
for the aneurysm wall from the pulsating blood flow and will
provide a means to prevent is migration of the graft due to the
enlarged area within the graft. An alternate method of construction
would be to attach a bulging outer skin to a standard tubular
thin-walled graft and provide a port for injection of the filler
substance. Alternatively, instead of a bulging outer skin, a very
compliant outer skin can be used so that the volume of material is
minimized. The compliant outer skin would be able to expand at very
low inflation pressures that would be non-destructive to the
aneurysm wall.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1A illustrates the two-part prosthesis.
[0011] FIG. 1B illustrates a bifurcated version of the expandable
tubular mesh structure and the expandable sponge structure.
[0012] FIG. 1C illustrates an expandable tubular mesh structure
placed across an aneurysm and the expandable sponge structure
filling up the aneurysm.
[0013] FIGS. 2A-2C illustrate the various cross-sections of the
expandable sponge structure.
[0014] FIG. 3A illustrates a long continuous sponge structure.
[0015] FIG. 3B illustrates multiple short sponge structures.
[0016] FIG. 4 illustrates the catheter-based delivery system.
[0017] FIG. 5 illustrates a curved delivery catheter.
[0018] FIG. 6 illustrates a method of ensuring that the delivery
catheter's tip stays inside the aneurysm sac.
[0019] FIG. 7A illustrates an expandable basket-like structure.
[0020] FIG. 7B illustrates an expandable braid-like structure.
[0021] FIGS. 8 and 9 illustrate expandable tubular mesh
structures.
[0022] FIG. 10 illustrates a delivery catheter tracked over a
guidewire and placed in a stent-graft which developed a leak.
[0023] FIG. 11 illustrates the sponge delivered through the
delivery catheter.
[0024] FIGS. 12-15 illustrate tubular balloon grafts.
[0025] FIGS. 16 and 17 illustrate tubular balloon grafts being
expanded. 100261 FIG. 18 illustrates a tubular balloon graft.
[0026] FIGS. 19, 20A and 20B illustrate a vascular graft with an
integrated tubular balloon.
[0027] FIGS. 21A-21E illustrate a method of delivering a graft with
an external balloon.
DETAILED DESCRIPTION OF THE INVENTION
[0028] FIG. 1A shows the two-part prosthesis comprising of an
expandable sponge structure 1 and an expandable tubular mesh
structure 2 placed in an abdominal aortic aneurysm 3 located in the
infra-renal aorta not involving the iliac arteries. FIG. 1B shows a
bifurcated version of the expandable tubular mesh structure 2 and
the expandable sponge structure 1 in an abdominal aortic aneurysm
located in the infra-renal aorta and involving both iliac arteries.
FIG. 1C shows an expandable tubular mesh structure 2 placed across
an aneurysm commonly found in cerebral arteries and the expandable
sponge structure 1 filling up the aneurysm. The expandable sponge
structure is placed through the expandable tubular mesh structure 2
into the aneurysm, filling up the aneurysmal sac which provides a
barrier between the thin fragile wall of the aneurysm and the
pressurized pulsating blood. The tubular mesh structure 2 keeps the
expanded sponge 1 within the confines of the aneurysm and away from
the flow path.
[0029] The expandable sponge structure 1 is preferably made of
common medical grade polymers or natural substances like collagen
which can be manufactured into a sponge structure. The sponge
structure can be processed in such a way so that it can be
compressed to a dry condition size substantially smaller than the
wet condition size, exhibiting huge expansion ratio. The expanded
sponge structure can take various forms. FIGS. 2A-2C show the
various expanded cross-sections that the expandable sponge
structure 1 can be, FIG. 2A shows a circular cross section, FIG. 2B
shows a square cross section, and FIG. 2C show a triangular cross
section. Any cross section can be used. The most important
requirement is that it cannot escape from the aneurysm sac through
a cell of the expandable tubular mesh structure 2. The length of
the expandable sponge structure 1 can vary as well. FIG. 3A shows a
long continuous structure 1. And FIG. 3B shows multiple short
structures 1.
[0030] One method of delivering the sponge filler 1 into the
aneurysm sac is shown by the catheter-based delivery system in FIG.
4. The catheter 4 can hold the compressed sponge 1 within its
lumen, and when pushed out with the plunger 5 into the blood filled
aneurysm sac, the sponge will expand out to a substantially larger
size. The expanded size of the sponge filler is preferably larger
than the largest opening of the tubular mesh structure as to
prevent the sponge from escaping the aneurysm sac. FIG. 5 shows an
example of a curved delivery catheter 4, where the tip is placed
through a cell of the tubular mesh structure 2 and the expandable
sponge structure 1 is being deployed into the aneurysm sac. It is
important that the tip of the delivery catheter is through a cell
of the tubular mesh structure into the aneurysm because the
expandable sponge will expand very quickly after being exposed to
the blood and being unconstrained by a catheter. FIG. 6 shows a
method of ensuring that the delivery catheter's 4 tip stays inside
the aneurysm sac by having a balloon 6 on the tip of it, and when
inflated after the tip is within the aneurysm sac it will prevent
the catheter tip from backing out of the aneurysm sac. FIG. 7A
shows an expandable basket-like structure 7 and FIG. 7B shows an
expandable braid-like structure 8 which are alternatives to having
a balloon 6 on the tip of the catheter 4.
[0031] The expandable tubular mesh structure 2 can be made of a
metal or of a polymer. The versions made of a metal can be
self-expanding from a smaller compressed state or balloon
expandable from a smaller compressed or as-cut state. The
self-expanding version may be made of metals which exhibit large
amounts of elasticity (i.e. nickel-titanium, spring steel, MP-35N
and elgiloy) such that when they are compressed down from their
expanded state to the compressed state to load into a delivery
catheter, they will substantially return to their expanded
condition when released from the catheter. is Alternatively, shape
memory metals like nickel-titanium can be used to provide large
expansion ratios. The balloon expandable version may be made of
metals which exhibit large permanent deformations without
significantly compromising the mechanical performance. The
following are some common medical grade metals which are well
suited for this purpose: stainless steel, titanium, tantalum, and
martensitic nickel titanium. In either the self-expanding or the
balloon expandable case, the intent is to deliver the expandable
tubular mesh 2 to the target site in a smaller or compressed
condition via a catheter-based delivery system so that the target
site can be accessed through a remote vascular access point which
is conducive to a percutaneous or minimally invasive approach.
[0032] The expandable tubular mesh structure 2 shown in FIGS. 1A,
1B, 1C, 5, and 6 represent a generic mesh structure. FIG. 8 shows
an expandable tubular mesh structure where long continuous struts 9
are connected to anchoring end members 10. This allows the
structure to be very low in profile in the compressed state, and
the durability of this type of structure can be optimized because
no radial element exists in the longitudinal struts 9. FIG. 9 show
an alternate expandable tubular mesh structure preferably made from
a polymer such as PTFE, Polyester, Polyurethane, and the like. The
structure has relatively large holes 11 to give access to the
expandable sponge delivery catheter. The ends incorporate an
anchoring member 12, either self-expanding or balloon
expandable.
[0033] FIG. 10 shows a delivery catheter 4 which has been tracked
over a guidewire 14, which has been placed into the aneurysm sac
through an opening 15 of an existing endoluminal stent-graft 13
which developed a leak. The balloon 6 on the delivery catheter 4
was inflated after the delivery catheter 4 was positioned within
the aneurysm sac. FIG. 11 shows the guidewire 14 removed, and the
expandable sponge structure 1 being delivered through the delivery
catheter 4.
[0034] FIG. 12 shows a section view of a tubular balloon graft 19
positioned across an infra-renal aortic aneurysm blocking off the
flow to the aneurysm sac. The wall of the tubular balloon graft 19
is made of an inner wall 16, an outer wall 17 and a chamber 18
between them. The chamber N can be filled with various materials to
dictate the mechanical properties of the prosthesis. FIG. 13 shows
a bifurcated tubular balloon graft 20 positioned across an
infra-renal aortic aneurysm with bi-lateral iliac involvement.
[0035] The tubular balloon implant can be made of the various
biocompatible materials used to make balloon catheters. Those
materials include P.E.T. (Polyester), nylon, urethane, and
silicone. It can also be made of other implant grade materials such
as ePTFE. One method of making such a device is to start with two
thin walled tubes of differing diameters. The difference between
the diameters of the tithes will dictate the volume of the balloon
chamber. The ends of the tubes can be sealed together with adhesive
or by heat to form the balloon chamber. A communication port will
be necessary to be able to fill the port with the injected
material.
[0036] The injected material can be an epoxy, a UV-curable epoxy,
silicone, urethane or other type of biocompatible materials such as
albumin, collagen, and gelatin glue which is injected into the
balloon, and then cured in situ. Or, the injected material doesn't
necessarily have to be cured. The as-delivered state may provide
the appropriate mechanical properties for the application.
Therefore, substances like sterile saline, biocompatible oils, or
biocompatible adhesives can be left in the tubular balloon in the
as-delivered state.
[0037] The tubular balloon graft can be non-porous to very porous.
FIG. 14 shows a version where the tubular balloon graft has a
porous outer wall 24. The chamber 21 of the tubular balloon graft
can be used to deliver an aneurysm sac filling substance such as UV
curable adhesive 22. The holes 23 which dictate the porosity of the
tubular balloon graft can be created with laser drilling, etching,
and other methods. The porosity can be varied in select areas of
the graft. FIG. 15 shows a tubular balloon graft with only the ends
of the graft have porosity to either promote cellular in-growth or
to inject an adhesive which allows secure attachment of the graft
ends to the vessel wall.
[0038] FIG. 16 shows a tubular balloon graft 19 which is being
expanded from a folded condition (not shown) by a balloon catheter
25. Once expanded, the chamber 18 of the tubular balloon graft 19
can be filled with the desired substance through the chamber access
port 26. FIG. 17 shows a tubular balloon graft 19 being expanded by
an inflation process or filling the chamber 18 of the tubular
balloon graft 19 through the chamber access port 26.
[0039] FIG. 18 shows a version of the tubular balloon graft with an
outer wall 17 which is substantially bulged out so that it fills
some or all of the aneurysm sac. FIG. 19 shows a vascular graft 27
which has an integrated balloon 28 attached to the outside surface
of the graft. The balloon can be pre-bulged and folded down for
delivery, or it can be a very compliant material like silicone,
urethane, or latex so that it has no folds whether compressed or
expanded. FIG. 20A shows the same type of implant, a graft 27 with
an external balloon 28, used in a cerebral vessel aneurysm 29. FIG.
20B show the same implant as 20A, except that the implant balloon
does not fully fill the aneurysm, which can be acceptable because
the graft 27 excludes the aneurysm from the blood flow, and the
primary purpose of the balloon 28 is to prevent migration of the
graft 27.
[0040] The graft 27 can be made of commonly used implant polymers
such as PTFE, Polyester, Polyurethane, etc. The balloon 28
surrounding the graft can be made of the same commonly used
vascular implant materials as well. The graft and balloon materials
can be different, but it is commonly known that using the same
material for both would facilitate processing/manufacturing. The
theory is that the balloon 28 would preferentially only deploy into
the aneurysm sac where the resistance to expansion is minimal as
compared to the vessel wall. The graft 27 would provide the primary
barrier between the pressurized blood and the thin wall of the
aneurysm. Secondarily, the balloon itself provides a buffer from
the pressurized blood. The balloon's 28 primary function, however,
is to hold the graft 27 in place. Since the expanded section of the
implant is "locked" into the aneurysm, the graft 27 should not
migrate. Also, the balloon 28, in the filled state, will provide
hoop strength to the graft 27.
[0041] FIGS. 21A-21E, demonstrate one method of delivering a graft
with an external balloon to the target site. FIG. 21A shows the
implant loaded onto a balloon delivery catheter 30 with an outer
sheath 32 and positioned over a guide wire 31 at the aneurysm
target site. FIG. 21B shows that once in position, the outer sheath
32 is withdrawn. FIG. 21C shows the balloon delivery catheter 33
being inflated, pushing the implant 34 against the healthy vessel
walls on both sides of the aneurysm. FIG. 21D shows that the
balloon delivery catheter 30 may also have an implant balloon
inflation port 35 which can now be used to fill up the implant
balloon 28 with a biocompatible substance. The substance can be
sterile saline, contrast agent, hydrogel, and UV cure adhesive to
name a few. Most likely, low inflation pressures would be used to
fill the implant balloon 28. FIG. 21E shows that once the implant
balloon 28 is filled, the implant balloon inflation port 35 can be
detached and the delivery catheter 30 removed.
* * * * *