U.S. patent application number 10/706660 was filed with the patent office on 2004-05-20 for dual wire placement catheter.
Invention is credited to Douglas, Myles, Madrid, Gilbert, Shaolian, Samuel M..
Application Number | 20040098087 10/706660 |
Document ID | / |
Family ID | 23367658 |
Filed Date | 2004-05-20 |
United States Patent
Application |
20040098087 |
Kind Code |
A1 |
Madrid, Gilbert ; et
al. |
May 20, 2004 |
Dual wire placement catheter
Abstract
Disclosed is a dual lumen access catheter, for facilitating
placement of two procedure wires across a treatment site. In one
application, the catheter is used to place a first wire extending
between a contralateral iliac and an ipsilateral iliac across the
terminal bifurcation of the aorta, and a second wire extending
through a portion of the ipsilateral iliac and into the aorta.
Methods of placing the wires, such as for subsequent deployment of
an abdominal aortic aneurysm bifurcation graft, are also
disclosed.
Inventors: |
Madrid, Gilbert; (Laguna
Niguel, CA) ; Douglas, Myles; (Phoenix, AZ) ;
Shaolian, Samuel M.; (Newport Beach, CA) |
Correspondence
Address: |
KNOBBE MARTENS OLSON & BEAR LLP
2040 MAIN STREET
FOURTEENTH FLOOR
IRVINE
CA
92614
US
|
Family ID: |
23367658 |
Appl. No.: |
10/706660 |
Filed: |
November 12, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10706660 |
Nov 12, 2003 |
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10035729 |
Dec 21, 2001 |
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6689157 |
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10035729 |
Dec 21, 2001 |
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09348356 |
Jul 7, 1999 |
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6440161 |
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Current U.S.
Class: |
623/1.11 ;
606/108 |
Current CPC
Class: |
A61M 25/0668 20130101;
A61F 2002/067 20130101; A61F 2230/0054 20130101; A61F 2/954
20130101; A61F 2/90 20130101; A61F 2220/0008 20130101 |
Class at
Publication: |
623/001.11 ;
606/108 |
International
Class: |
A61F 002/06 |
Claims
What is claimed is:
1. A multilumen catheter, comprising: an elongate, flexible tubular
body, having a proximal end and a distal end; a first lumen
extending throughout the length of the tubular body, between the
proximal end and the distal end; and a second lumen extending
between a proximal port and a distal port; wherein at least the
distal port is spaced proximally apart from the distal end.
2. A multilumen catheter as in claim 1, further comprising an
axially extending tear line in the wall defining the second
lumen.
3. A multilumen catheter as in claim 2, wherein the tear line
comprises a perforation line.
4. A multilumen catheter as in claim 2, wherein the second lumen is
defined within a wall, and the tear line comprises a reduced
thickness in the wall.
5. A multilumen catheter as in claim 4, wherein the tear line
comprises an axially extending recess in the wall.
6. A multilumen catheter as in claim 5, wherein the recess extends
radially outwardly from an interior surface of the wall.
7. A multilumen catheter as in claim 1, wherein the distal port is
spaced proximally apart from the distal end by at least about 2
cm.
8. A multilumen catheter as in claim 1, further comprising an
axially extending slit in the wall of the second lumen.
9. A multilumen catheter as in claim 1, wherein the length of the
second lumen is within the range of from about 20% to about 60% of
the length of the catheter.
10. A method of positioning a first wire through a portion of the
ipsilateral iliac, across the bifurcation of the aorta and through
a portion of the contralateral iliac, and a second wire through the
portion of the ipsilateral iliac and into the aorta, comprising the
steps of: introducing a catheter through a first access site and
into a first iliac, the catheter having at least first and second
lumens; advancing the catheter superiorly to the bifurcation of the
aorta and inferiorly down a second iliac to a second access site;
introducing a first wire through the first lumen and between the
first access site and-the second access site; introducing a second
wire through the second lumen superiorly through the ipsilateral
iliac and into the aorta; and removing the catheter, while leaving
the first and second wires in place.
11. A method as in claim 10, wherein the removing step comprises
tearing the wall of the second lumen in response to proximal
retraction of the catheter.
12. A method as in claim 10, wherein the advancing the catheter
step comprises advancing the catheter along a third wire.
13. A method as in claim 10, wherein the first wire comprises a
release wire for releasing the contralateral iliac branch of a
bifurcation graft from a constrained configuration to an expanded
configuration.
14. A method as in claim 10, further comprising the step of
introducing a bifurcation graft delivery catheter into the aorta
along the second wire.
15. A method of transluminally deploying a bifurcation graft at the
bifurcation of the aorta into the ipsilateral and contralateral
iliacs, comprising the steps of: introducing a catheter through a
first access site and into the ipsilateral iliac, the catheter
having at least first and second lumens; advancing the catheter
superiorly to the bifurcation of the aorta and inferiorly down the
contralateral iliac to a second access site; introducing a first
wire through the first lumen from the first access site through the
second access site; introducing a second wire through the second
lumen from the first access site superiorly through the ipsilateral
iliac and into the aorta; and removing the catheter, while leaving
the first and second wires in place.
16. A method of transluminally deploying a bifurcation graft at the
bifurcation of the aorta into the ipsilateral and contralateral
iliacs, comprising the steps of: introducing a catheter through a
first access site and into the contralateral iliac, the catheter
having at least first and, second lumens; advancing the catheter
superiorly to the bifurcation of the aorta and inferiorly down the
ipsilateral iliac to a second access site; introducing a first wire
through the first lumen between the first access site and the
second access site; introducing a second wire through the second
lumen from the second access site superiorly through the
ipsilateral iliac and into the aorta; and removing the catheter,
while leaving the first and second wires in place.
17. A method as in claim 16, wherein the removing step comprises
tearing the wall of the second lumen in response to proximal
retraction of the catheter.
18. A method as in claim 16, wherein the advancing the catheter
step comprises advancing the catheter along a third wire.
19. A method as in claim 16, wherein the first wire comprises a
release wire for releasing the contralateral iliac branch of a
bifurcation graft from a constrained configuration to an expanded
configuration.
20. A method as in claim 16, further comprising the step of
introducing a bifurcation graft delivery catheter into the aorta
along the second wire.
Description
PRIORITY INFORMATION
[0001] The present application is a continuation application of
U.S. patent application Ser. No. 09/348,356 filed Jul. 7, 1999;
this application claims priority to the earlier filed application
under 35 U.S.C. .sctn.120.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to catheters, and, in
particular, to a dual lumen catheter for use in positioning two
wires in a vascular bifurcation such as in connection with the
treatment of abdominal aortic aneurysms.
[0003] An abdominal aortic aneurysm is a sac caused by an abnormal
dilation of the wall of the aorta, a major artery of the body, as
it passes through the abdomen. The abdomen is that portion of the
body which lies between the thorax and the pelvis. It contains a
cavity, known as the abdominal cavity, separated by the diaphragm
from the thoracic cavity and lined with a serous membrane, the
peritoneum. The aorta is the main trunk, or artery, from which the
systemic arterial system proceeds. It arises from the left
ventricle of the heart, passes upward, bends over and passes down
through the thorax and through the abdomen to about the level of
the fourth lumbar vertebra, where it divides into the two common
iliac arteries.
[0004] The aneurysm usually arises in the infrarenal portion of the
diseased aorta, for example, below the kidneys. When left
untreated, the aneurysm may eventually cause rupture of the sac
with ensuing fatal hemorrhaging in a very short time. High
mortality associated with the rupture led initially to
transabdominal surgical repair of abdominal aortic aneurysms.
Surgery involving the abdominal wall, however, is a major
undertaking with associated high risks. There is considerable
mortality and morbidity associated with this magnitude of surgical
intervention, which in essence involves replacing the diseased and
aneurysmal segment of blood vessel with a prosthetic device which
typically is a synthetic tube, or graft, usually fabricated of
Polyester, Urethane, DACRON.RTM. TEFLON.RTM., or other suitable
material.
[0005] To perform the surgical procedure requires exposure of the
aorta through an abdominal incision which can extend from the rib
cage to the pubis. The aorta must be closed both above and below
the aneurysm, so that the aneurysm can then be opened and the
thrombus, or blood clot, and arteriosclerotic debris removed. Small
arterial branches from the backwall of the aorta are tied off. The
DACRON.RTM. tube, or graft, of approximately the same size of the
normal aorta is sutured in place, thereby replacing the aneurysm.
Blood flow is then reestablished through the graft. It is necessary
to move the intestines in order to get to the back wall of the
abdomen prior to clamping off the aorta.
[0006] If the surgery is performed prior to rupturing of the
abdominal aortic aneurysm, the survival rate of treated patients is
markedly higher than if the surgery is performed after the aneurysm
ruptures, although the mortality rate is still quite high. If the
surgery is performed prior to the aneurysm rupturing, the mortality
rate is typically slightly less than 10%. Conventional surgery
performed after the rupture of the aneurysm is significantly
higher, one study reporting a mortality rate of 66.5%. Although
abdominal aortic aneurysms can be detected from routine
examinations, the patient does not experience any pain from the
condition. Thus, if the patient is not receiving routine
examinations, it is possible that the aneurysm will progress to the
rupture stage, wherein the mortality rates are significantly
higher.
[0007] Disadvantages associated with the conventional, prior art
surgery, in addition to the high mortality rate include the
extended recovery period associated with such surgery; difficulties
in suturing the graft, or tube, to the aorta; the loss of the
existing aorta wall and thrombosis to support and reinforce the
graft; the unsuitability of the surgery for many patients having
abdominal aortic aneurysms; and the problems associated with
performing the surgery on an emergency basis after the aneurysm has
ruptured. A patient can expect to spend from one to two weeks in
the hospital after the surgery, a major portion of which is spent
in the intensive care unit, and a convalescence period at home from
two to three months, particularly if the patient has other
illnesses such as heart, lung, liver, and/or kidney disease, in
which case the hospital stay is also lengthened. The graft must be
secured, or sutured, to the remaining portion of the aorta, which
may be difficult to perform because of the thrombosis present on
the remaining portion of the aorta. Moreover, the remaining portion
of the aorta wall is frequently friable, or easily crumbled.
[0008] Since many patients having abdominal aortic aneurysms have
other chronic illnesses, such as heart, lung, liver and/or kidney
disease, coupled with the fact that many of these patients are
older, the average age being approximately 67 years old, these
patients are not ideal candidates for such major surgery.
[0009] More recently, a significantly less invasive clinical
approach to aneurysm repair, known as endovascular grafting, has
been developed. Parodi, et al. provide one of the first clinical
descriptions of this therapy. Parodi, J. C., et al., "Transfemoral
Intraluminal Graft Implantation for Abdominal Aortic Aneurysms," 5
Annals of Vascular Surgery 491 (1991). Endovascular grafting
involves the transluminal placement of a prosthetic arterial graft
within the lumen of the artery.
[0010] In general, transluminally implantable prostheses adapted
for use in the abdominal aorta comprise a tubular wire cage
surrounded by a tubular PTFE or Dacron sleeve. Both balloon
expandable and self expandable support structures have been
proposed. Endovascular grafts adapted to treat both straight
segment and bifurcation aneurysms have also been proposed.
[0011] One persistent challenge in the context of implanting an
endoluminal bifurcation graft relates to the proper positioning of
the procedure wires across the deployment site. The most recent
procedures and devices require a puncture or cut-down in both the
right and left femoral arteries, and the time consuming step of
placing a guidewire across the bifurcation between the
contralateral and ipsilateral iliacs. A second wire must also be
introduced into the ipsilateral iliac and advanced beyond the
bifurcation into the aorta. Due to the two-dimensional viewing
media currently available for such procedures, the clinician cannot
visually tell if two guidewires are crossed or separated. As the
advancement of two guidewires is made to separate sites,
advancement of one guidewire may limit the advancement of the other
if the wires become crossed.
[0012] Thus, notwithstanding the many advances which have been made
in recent years in the treatment of abdominal aortic aneurysms,
there remains a need for an improved method and device for more
efficiently introducing a first contralateral-ipsilateral iliac
wire and a second ipsilateral-aorta wire which may subsequently be
used for positioning and/or deployment steps in a bifurcation graft
deployment procedure.
SUMMARY OF THE INVENTION
[0013] There is provided in accordance with one aspect of the
present invention, a multi-lumen catheter. The catheter comprises
an elongate flexible tubular body, having a proximal end and a
distal end. A first lumen extends throughout the length of the
tubular body, between the proximal end and the distal end. A second
lumen extends between a proximal port and a distal port, wherein
the proximal port is spaced apart from the proximal end of the
catheter and the distal port is spaced apart from the distal end of
the catheter. The distal port is spaced proximally apart from the
distal end of the catheter by at least about two centimeters,
preferably at least about 10 cm and, in one embodiment, at least
about 17 cm.
[0014] Preferably, the second lumen is defined by a wall which
further comprises an axially extending tear line. The tear line may
comprise a perforation line, and/or a reduced wall thickness.
Alternatively, the second lumen is defined by a wall which further
comprises an axially extending slit.
[0015] In accordance with another aspect of the present invention,
there is provided a method of positioning a first wire through a
portion of the ipsilateral iliac, across the bifurcation of the
aorta and through at least a portion of the contralateral iliac.
Additionally, a second wire is advanced through a portion of the
ipsilateral iliac and into the aorta.
[0016] The method comprises the steps of introducing a catheter
through a first access site into the contralateral iliac, the
catheter having at least first and second lumens. The catheter is
advanced superiorly to the bifurcation of the aorta and inferiorly
down the ipsilateral iliac to a second access site. A first wire is
introduced through the first lumen from the second access site
through the first access site. A second wire is introduced through
the second lumen from the second access site superiorly through the
ipsilateral iliac, exiting a proximal port and into the aorta. The
catheter is thereafter removed, while leaving the first and second
wires in place.
[0017] Preferably, the removing step comprises tearing the wall of
the second lumen, in response to proximal retraction of the
catheter.
[0018] In one application of the invention, the method further
comprises the step of introducing a bifurcation graft delivery
catheter and advancing it along the second wire into the aorta. The
first wire comprises a release wire for releasing the contralateral
iliac branch of the bifurcation graft, from a constrained
configuration to an expanded configuration within the contralateral
iliac.
[0019] Further features and advantages of the present invention
will become apparent to those of skill in the art in view of the
detailed description of preferred embodiments which follows, when
considered together with the attached drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a side elevational schematic cross-section of a
dual lumen catheter in accordance with the present invention.
[0021] FIG. 1A is a side elevational view of one embodiment of a
dual lumen catheter in accordance with the present invention.
[0022] FIG. 1B is a cross section taken along the line 1B-1B in
FIG. 1A.
[0023] FIG. 1C is a detailed view taken along the line 1C-1C in
FIG. 1A.
[0024] FIG. 2 is a cross-section along the line 2-2 in FIG. 1.
[0025] FIG. 3 is a schematic representation of the bifurcation of
the lower abdominal aorta into the ipsilateral and contralateral
iliacs, with a standard guidewire inserted from the contralateral
to the ipsilateral iliac.
[0026] FIG. 4 is a schematic representation as in FIG. 3, with the
dual lumen catheter positioned over the guidewire.
[0027] FIG. 5 is a schematic representation as in FIG. 4, after the
guidewire has been removed from the dual lumen catheter.
[0028] FIG. 6 is a schematic representation as in FIG. 5, after the
delivery system guidewire has been advanced through the second wire
lumen of the dual lumen catheter.
[0029] FIG. 7 is a schematic representation as in FIG. 6, with the
contralateral branch deployment guidewire positioned within the
dual lumen catheter.
[0030] FIG. 8 is a schematic representation as in FIG. 7, with the
dual lumen catheter in the process of being removed from the
contralateral iliac, leaving both the delivery system guidewire and
the contralateral deployment guidewire in position.
[0031] FIG. 9 is a schematic representation of an exemplary wire
support structure for a bifurcated vascular prosthesis useful with
the present invention, showing a main body support structure and
separate branch support structures.
[0032] FIG. 10 is a schematic representation of the wire support
structure as shown in FIG. 9, illustrating sliding articulation
between the branch supports and the main body support.
[0033] FIG. 11 is a plan view of a formed wired useful for rolling
about an axis to form a branch support structure in accordance with
the embodiment shown in FIG. 9.
[0034] FIGS. 12A, 12B and 12C are enlargements of the apexes
delineated by lines A, B and C respectively in FIG. 11.
[0035] FIG. 13 is a side elevational cross-section of a bifurcation
graft delivery catheter useful for introducing a bifurcation graft
along the guidewires placed by the dual lumen access catheter of
the present invention.
[0036] FIG. 14 is an enlargement of the portion delineated by the
line 14-14 in FIG. 13.
[0037] FIG. 15 is a cross-section taken along the line 15-15 in
FIG. 14.
[0038] FIG. 16 is a cross-section taken along the line 16-16 in
FIG. 14.
[0039] FIG. 17 is a schematic representation of a bifurcated graft
deployment catheter positioned within the ipsilateral iliac and the
aorta, with the contralateral guidewire positioned within the
contralateral iliac.
[0040] FIG. 18 is a schematic representation as in FIG. 17, with
the outer sheath proximally retracted and the compressed iliac
branches of the graft moving into position within the iliac
arteries.
[0041] FIG. 19 is a schematic representation as in FIG. 18, with
the compressed iliac branches of the graft within the iliac
arteries, and the main aortic trunk of the graft deployed within
the aorta.
[0042] FIG. 20 is a schematic representation as in FIG. 19, with
the contralateral iliac branch of the graft deployed.
[0043] FIG. 21 is a schematic representation as in FIG. 20,
following deployment of the ipsilateral branch of the graft.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0044] Referring to FIG. 1, there is illustrated a dual lumen
catheter 20 in accordance with one aspect of the present invention.
The dual lumen catheter 20 comprises a proximal end 22, a distal
end 24 and an elongate flexible tubular body 26 extending
therebetween.
[0045] In one application of the present invention the dual lumen
catheter 20 is used to position wires for the purpose of
transluminal introduction of an expandable graft at the bifurcation
of the lower abdominal aorta and the ipsilateral and contralateral
iliac arteries. In this application, the tubular body 26 has a
length of within the range of from about 80 cm to about 100 cm and
an outside diameter within the range of from about 0.105" to about
0.120". In one embodiment, the length is about 90 cm and the
outside diameter is no more than about 0.110".
[0046] Tubular body 26 may be formed in any of a variety of manners
which are well known in the art of catheter body manufacturing,
such as by braiding and/or extrusion. Suitable extrudable materials
include high density polyethylene, medium density polyethylene and
other polyethylene blends, nylon, PEBAX, and others well known in
the art. Reinforced tubular bodies may be produced by including a
braided layer in or on the wall. The braided wall may comprise any
of a variety of materials such as stainless steel, nitinol,
composite fibers and others known in the art. Additional details
concerning the tubular body 26 will be recited below.
[0047] The tubular body 26 is provided with a first guidewire lumen
28, extending axially therethrough between a proximal access port
30 and a distal access port 32. First lumen 28 preferably has an
inside diameter of at least about 0.041" to accommodate a standard
0.035" diameter guidewire. Other inside diameters for first lumen
28 can readily be provided, based upon the desired guidewire
diameter as is well understood in the art.
[0048] A second wire lumen 34 extends throughout at least a portion
of the tubular body 26, between a proximal port 36 and a distal
port 38. In an embodiment of the catheter 20 intended for
implantation of a bifurcation prosthesis at the bifurcation of the
abdominal aorta into the iliacs, the proximal access port 36 is
positioned within the range of from about 40 cm to about 60 cm from
the distal port 32. The distal port 38 is positioned within the
range of from about 15 cm to about 20 cm from the distal port 32.
The inside diameter of the second lumen 34 is configured to
slideably receive a delivery system guidewire therethrough. In one
embodiment, the inside diameter of the second lumen 34 is about
0.041", for use with a delivery system guidewire having an outside
diameter of about 0.035".
[0049] In general, the axial distance between the proximal port 36
and the distal port 38 is sufficient to extend from a point outside
of the body through an ipsilateral iliac puncture to about the
bifurcation between the contralateral and ipsilateral iliacs. Thus,
the length can vary depending upon the intended access site
location along the femoral artery and the desired length of the
dual lumen portion of the catheter which is to extend outside of
the body.
[0050] The axial distance between proximal port 30 and proximal
port 36 should be sufficient to extend from a point outside the
contralateral femoral access site to the bifurcation. Typically,
this length will be within the range from about 30 cm to about 40
cm, and usually at least about 35 cm.
[0051] The second lumen 34 is provided with a release or tear line
40, such as a crease, slot, series of perforations or other
structure for facilitating easy opening or tearing of the side wall
of the lumen 34, to permit the second wire extending through lumen
34 to be peeled laterally away from the catheter 20 as will be
discussed. Alternatively, an axially extending slot may be provided
in the radially outwardly facing wall of second lumen 34.
Preferably, the two coaptive edges of the slot are biased into a
closed position in contact or close proximity to each other under
the resilience of the catheter body material. Thus, an axially
extending slot which has a circumferential width of less than the
diameter of the guidewire will retain the guidewire within the
second lumen. However, the wall of the second lumen is sufficiently
flexible that the guidewire may be peeled laterally through the
slot by a plastic deformation thereof. Specific slot width and
guidewire diameter relationships can be optimized through routine
experimentation by one of skill in the art in view of the
disclosure herein. In one embodiment, the tear line 40 is produced
by an axially extending slot.
[0052] Dimensions of one particular embodiment of the present
invention will be described in connection with FIGS. 1A through 1C.
In this embodiment, the working length of the dual lumen catheter
20 is approximately 90.+-.1.5 cm. The catheter body comprises a
PEBAX extrusion, having a braided wire for reinforcing the first
lumen 28. The braid filament comprises a round wire having a cross
section of about 0.002". The proximal port 36 is spaced about 35.5
cm from the proximal luer connector. Port 36 has an axial length of
about 1 cm, and is shaped as illustrated in FIG. 1C. The length of
second lumen 34 between proximal port 36 and distal port 38 is
about 35 cm. Distal port 38 has an axial length of about 1 cm, and
the distal end of the catheter is about 17.5 cm beyond the distal
edge of distal port 38. The diameter of the dual lumen catheter 20
at cross section 1B-1B is about 0.110". The inside diameter of the
first lumen 28 is about 0.041", and the inside diameter of the
second lumen 34 is about 0.039". Proximal and distal extensions of
the second lumen 34 beyond the proximal port 36 and distal port 38
which are produced by the extrusion molding process as will be
understood by those of skill in the art can be occluded such as by
the introduction of a UV curable glue plug. At least the proximal
plug adjacent proximal port 36 may be further provided with a
radiopaque marker such as a gold marker to facilitate visualization
during placement.
[0053] The foregoing dimensions and materials can be varied widely
as will be appreciated by those of skill in the art in view of the
desired performance characteristics and manufacturing techniques.
In addition, the proximal port 36 and distal port 38 may be
positioned elsewhere along the length of the catheter 20, as may be
desired, to "reverse" the introduction method described in greater
detail below. For example, although the discussion below relates to
a design for a dual lumen catheter 20 intended for introduction
into the contralateral iliac with a distal end exiting the
ipsilateral iliac, the catheter 20 may also be adapted for
introduction into the ipsilateral iliac as the primary access site.
In this application, the catheter 20 is introduced into the
ipsilateral iliac, advanced superiorly towards the aorta, and
subsequently advanced inferiorly down the contralateral iliac and
out the contralateral access site. The first and second wires are
advanced distally through the catheter 20, one extending through a
lateral exit port and into the abdominal aorta and the other
exiting the contralateral iliac. The catheter 20 is thereafter
proximally retracted from the ipsilateral iliac as will be apparent
to those of skill in the art in view of the detailed description
below, leaving the wires in place.
[0054] The method of using the dual lumen catheter 20 of the
present invention will be described in connection with FIGS. 3
through 8. Referring to FIG. 3, there is disclosed a schematic
representation of the abdominal part of the aorta and its principal
branches. In particular, the abdominal aorta 42 is characterized by
a right renal artery 44 and left renal artery 46. The large
terminal branches of the aorta are the right and left common iliac
arteries 48 and 50. Additional vessels (e.g. second lumbar,
testicular, inferior mesenteric, middle sacral) have been omitted
for simplification. An abdominal aortic aneurysm 52 is illustrated
in the infrarenal portion of the diseased aorta.
[0055] A standard 0.035" diameter guidewire 54 is in position
across the ipsilateral and contralateral iliacs 48 and 50. In
accordance with the method of the present invention, the guidewire
54 is introduced from the contralateral side through a percutaneous
puncture, and advanced superiorly towards the aorta 42. A retrieval
catheter is introduced superiorly through a vascular access site
and into the ipsilateral iliac, and used to grasp the guidewire 54
and retract it inferiorly and out through the ipsilateral vascular
access site in accordance with known techniques.
[0056] Referring to FIG. 4, the dual lumen catheter 20 is advanced
over the guidewire 54 from the contralateral access site along the
guidewire 54 and out the ipsilateral access site. The guidewire is
thereafter removed as seen in FIG. 5, leaving the dual lumen
catheter 20 in position. The proximal end 22 of the dual lumen
catheter 20 is positioned outside the patient on the contralateral
iliac side, and the distal end 24 including the distal port 38 on
second lumen 34 of dual lumen catheter 20 is positioned outside the
patient on the ipsilateral iliac side.
[0057] Referring to FIG. 6, the delivery system guidewire 56 is
introduced into the distal port 38 of the peel-away lumen 34. The
delivery system guidewire 56 is advanced until the distal end 58 of
the delivery system guidewire 56 extends out through proximal port
36 and across the aneurysm 52 into the aorta 42.
[0058] The second procedure wire, typically a contralateral limb
release wire 66, is introduced into and advanced throughout the
first guidewire lumen 28. In a preferred application of the present
invention, the wire 66 is the contralateral deployment wire, and is
therefore introduced into the distal port 32 and advanced
throughout the length of the first guidewire lumen 28 such that it
exists the proximal port 30 on dual wire catheter 20. As shown in
FIG. 8, the dual wire catheter 20 may thereafter be proximally
retracted through the contralateral access site. The two wires 56
and 66 are manually retained in position such as by grasping the
portions of the wires which extend from the ipsilateral access
site. Proximal retraction of the dual wire catheter 20 from the
contralateral access site causes the wire 56 to pull laterally
through the wall of the second lumen 34 as has been discussed. In
this manner, the dual wire catheter 20 may be removed from the
body, leaving wires 56 and 66 in position.
[0059] Referring to FIG. 9, there is disclosed an exploded
schematic representation of a hinged or articulated tubular wire
support structure for a bifurcated graft which may be deployed
following placement of the procedure wires 56 and 66 discussed
above. The tubular wire support comprises a main body, or aortic
trunk portion 200 and right 202 and left 204 iliac branch portions.
Right and left designations correspond to the anatomic designations
of right and left common iliac arteries. The proximal end 206 of
the aortic trunk portion 200 has apexes 211-216 adapted for
connection with the complementary apexes on the distal ends 208 and
210 of the right 202 and left 204 iliac branch portions,
respectively. Complementary pairing of apexes is indicated by the
shared numbers, wherein the right branch portion apexes are
designated by (R) and the left branch portion apexes are designated
by (L). Each of the portions may be formed from a continuous single
length of wire. See FIG. 11.
[0060] Referring to FIG. 10, the assembled articulated wire support
structure is shown. The central or medial apex 213 in the
foreground (anterior) of the aortic trunk portion 200 is linked
with 213(R) on the right iliac portion 202 and 213(L) on the left
iliac portion 204. Similarly, the central apex 214 in the
background (posterior) is linked with 214(R) on the right iliac
portion 202 and 214(L) on the left iliac portion 204. Each of these
linkages has two iliac apexes joined with one aortic branch apex.
The linkage configurations may be of any of the variety described
above in FIGS. 7A-D. The medial most apexes 218 (R) and (L) of the
iliac branch portions 202 and 204 are linked together, without
direct connection with the aortic truck portion 200.
[0061] The medial apexes 213 and 214 function as pivot points about
which the right and left iliac branches 202, 204 can pivot to
accommodate unique anatomies. Although the right and left iliac
branches 202, 204 are illustrated at an angle of about 450 to each
other, they are articulable through at least an angle of about
90.degree. and preferably at least about 120.degree.. The
illustrated embodiment allows articulation through about
180.degree. while maintaining patency of the central lumen. To
further improve patency at high iliac angles, the apexes 213 and
214 can be displaced proximally from the transverse plane which
roughly contains apexes 211, 212, 215 and 216 by a minor adjustment
to the fixture about which the wire is formed. Advancing the pivot
point proximally relative to the lateral apexes (e.g., 211, 216)
opens the unbiased angle between the iliac branches 202 and
204.
[0062] In the illustrated embodiment, the pivot point is formed by
a moveable link between an eye on apex 213 and two apexes 213R and
213L folded therethrough. To accommodate the two iliac apexes 213R
and 213L, the diameter of the eye at apex 213 may be slightly
larger than the diameter of the eye on other apexes throughout the
graft. Thus, for example, the diameter of the eye at apex 213 in
one embodiment made from 0.014" diameter wire is about 0.059",
compared to a diameter of about 0.020" for eyes elsewhere in the
graft.
[0063] Although the pivot points (apexes 213, 214) in the
illustrated embodiment are on the medial plane, they may be moved
laterally such as, for example, to the axis of each of the iliac
branches. In this variation, each iliac branch will have an
anterior and a posterior pivot link on or about its longitudinal
axis, for a total of four unique pivot links at the bifurcation.
Alternatively, the pivot points can be moved as far as to lateral
apexes 211 and 216. Other variations will be apparent to those of
skill in the art in view of the disclosure herein.
[0064] To facilitate lateral rotation of the iliac branches 202,
204 about the pivot points and away from the longitudinal axis of
the aorta trunk portion 200 of the graft, the remaining links
between the aorta trunk portion 200 and the iliac branches 202, 204
preferably permit axial compression and expansion. In general, at
least one and preferably several links lateral to the pivot point
in the illustrated embodiment permit axial compression or
shortening of the graft to accommodate lateral pivoting of the
iliac branch. If the pivot point is moved laterally from the
longitudinal axis of the aorta portion of the graft, any links
medial of the pivot point preferably permit axial elongation to
accommodate lateral rotation of the branch. In this manner, the
desired range of rotation of the iliac branches may be accomplished
with minimal deformation of the wire, and with patency of the graft
optimized throughout the angular range of motion.
[0065] To permit axial compression substantially without
deformation of the wire, the lateral linkages, 211 and 212 for the
right iliac, and 215 and 216 for the left iliac, may be different
from the apex-to-apex linkage configurations illustrated elsewhere
on the graft. The lateral linkages are preferably slideable
linkages, wherein a loop formed at the distal end of the iliac apex
slidably engages a strut of the corresponding aortic truck portion.
The loop and strut orientation may be reversed, as will be apparent
to those of skill in the art. Interlocking "elbows" without any
distinct loop may also be used. Such an axially compressible
linkage on the lateral margins of the assembled wire support
structure allow the iliac branch portions much greater lateral
flexibility, thereby facilitating placement in patients who often
exhibit a variety of iliac branch asymmetries and different angles
of divergence from the aortic trunk.
[0066] Referring to FIG. 11, there is illustrated a plan view of a
single formed wire used for rolling about a longitudinal axis to
produce a four segment straight tubular wire support for an iliac
limb. The formed wire exhibits distinct segments, each
corresponding to an individual tubular segment in the tubular
supports 202 or 204 (See FIG. 9). The distal segment I, is adapted
to articulate with the aortic trunk portion 200 and the adjacent
iliac limb portion. The distal segment (I) has two apexes (e.g.
corresponding to 211 and 212 on the right iliac portion 202 in FIG.
9) which form a loop adapted to slidably engage a strut in the
lateral wall of the aortic portion. These articulating loops (A)
are enlarged in FIG. 12A. As discussed above, the loops are
preferably looped around a strut on the corresponding apex of the
proximal aortic segment to provide a sliding linkage.
[0067] The apex 218 is proximally displaced relative to the other
four apexes in the distal segment (1). Apex 218 (R or L) is
designed to link with the complementary 218 apex on the other iliac
branch portion (See FIG. 10). The apex 218 in the illustrated
embodiment is formed adjacent or near an intersegment connector 66,
which extends proximally from the distal segment.
[0068] The other apexes on the distal segment (I) of an iliac limb
are designed to link with a loop on the corresponding apex of the
proximal aortic segment. Because many variations of this linkage
are consistent with the present invention (See U.S. patent
application Ser. No. 09/251,363, filed Feb. 17, 1999, entitled
Articulated Bifurcation Graft, the disclosure of which is
incorporated in its entirety herein by reference), the form of the
corresponding apexes may vary. In a preferred variation, the apexes
(B) form a narrow U-shape, having an inside diameter of about
0.019" in an embodiment made from 0.012" Conichrome wire (tensile
strength 300 ksi minimum) as illustrated in FIG. 12B. The U-shaped,
elongated axial portion of the apex shown in FIG. 12B permits the
apex to be wrapped through and around a corresponding loop apex of
the proximal aortic segment.
[0069] In more general terms, the wire support illustrated in FIGS.
9 and 10 comprises a main body support structure formed from one or
more lengths of wire and having a proximal end, a distal end and a
central lumen extending along a longitudinal axis. The wire support
also comprises a first branch support structure formed from one or
more lengths of wire and having a proximal end, a distal end and a
central lumen therethrough. The first branch support structure is
pivotably connected to the proximal end of the main body support
structure. The tubular wire support further comprises a second
branch support structure formed from one or more lengths of wire
and having a proximal end, a distal end and a central lumen
extending therethrough. The distal end of the second branch support
structure is pivotably connected to the proximal end of the main
body support structure.
[0070] Further, the distal ends of the first and second branch
structures may be joined together by a flexible linkage, formed for
example between apexes 218(R) and 218(L) in FIG. 9. By
incorporating a medial linkage between the two branch support
structures and pivotable linkages with the main trunk, the first
and second branch support structures can hinge laterally outward
from the longitudinal axis without compromising the volume of the
lumen. Thus, the branches may enjoy a wide range of lateral
movement, thereby accommodating a variety of patient and vessel
heterogeneity. Additional corresponding apexes between the main
trunk and each iliac branch may also be connected, or may be free
floating within the outer polymeric sleeve. Axially compressible
lateral linkages, discussed above an illustrated in FIG. 10, may
optionally be added.
[0071] The proximal apexes (C) of the iliac limb portions are
adapted to link with the distal apexes of the next segment. These
proximal apexes preferably form loops, such as those illustrated in
FIG. 12C, wherein the elongated axial portions of the corresponding
proximal apex in the adjacent segment can wrap around the loop,
thereby providing flexibility of the graft.
[0072] The wire may be made from any of a variety of different
alloys and wire diameters or non-round cross-sections, as has been
discussed. In one embodiment of the bifurcation graft, the wire
gauge remains substantially constant throughout the aorta component
and steps down to a second, smaller cross-section throughout the
iliac component.
[0073] A wire diameter of approximately 0.018" may be useful in the
aorta trunk portion of a graft having five segments each having 2.0
cm length per segment, each segment having six struts intended for
use in the aorta, while a smaller diameter such as 0.012" might be
useful for segments of the graft having 6 struts per segment
intended for the iliac artery.
[0074] In one embodiment of the present invention, the wire
diameter may be tapered throughout from the proximal to distal ends
of the aorta section and/or iliac section. Alternatively, the wire
diameter may be tapered incremental or stepped down, or stepped up,
depending on the radial strength requirements of each particular
clinical application. In one embodiment, intended for the abdominal
aortic artery, the wire has a cross-section of about 0.018" in the
proximal zone and the wire tapers down regularly or in one or more
steps to a diameter of about 0.012" in the distal zone of the
graft. End point dimensions and rates of taper can be varied
widely, within the spirit of the present invention, depending upon
the desired clinical performance.
[0075] In general, in the tapered or stepped wire embodiments, the
diameter of the wire in the iliac branches is no more than about
80% of the diameter of the wire in the aortic trunk. This permits
increased flexibility of the graft in the region of the iliac
branches, which has been determined by the present inventors to be
clinically desirable.
[0076] The collapsed prosthesis in accordance with the present
invention has a diameter in the range of about 2 to about 10 mm.
Preferably, the maximum diameter of the collapsed prosthesis is in
the range of about 3 to 6 mm (12 to 18 French). Some embodiments of
the delivery catheter including the prosthesis will be in the range
of from 18 to 20 or 21 French; other embodiments will be as low as
19 F, 16 F, 14 F, or smaller. After deployment, the expanded
endoluminal vascular prosthesis has radially self-expanded to a
diameter anywhere in the range of about 20 to 40 mm, corresponding
to expansion ratios of about 1:2 to 1:20. In a preferred
embodiment, the expansion ratios range from about 1:4 to 1:8, more
preferably from about 1:4 to 1:6.
[0077] The self expandable bifurcation graft of the present
invention can be deployed at a treatment site in accordance with
any of a variety of techniques as will be apparent to those of
skill in the art. One such technique is disclosed in copending
patent application Ser. No. 08/802,478 entitled Bifircated Vascular
Graft and Method and Apparatus for Deploying Same, filed Feb. 20,
1997, the disclosure of which is incorporated in its entirety
herein by reference.
[0078] A partial cross-sectional side elevational view of one
deployment apparatus 120 in accordance with the present invention
is shown in FIG. 13. The deployment apparatus 120 comprises an
elongate flexible multicomponent tubular body 122 having a proximal
end 124 and a distal end 126. The tubular body 122 and other
components of this system can be manufactured in accordance with
any of a variety of techniques well known in the catheter
manufacturing field. Suitable materials and dimensions can be
readily selected taking into account the natural anatomical
dimensions in the iliacs and aorta, together with the dimensions of
the desired percutaneous access site.
[0079] The elongate flexible tubular body 122 comprises an outer
sheath 128 which is axially movably positioned upon an intermediate
tube 130. A central tubular core 132 is axially movably positioned
within the intermediate tube 130. In one embodiment, the outer
tubular sheath comprises extruded PTFE, having an outside diameter
of about 0.250" and an inside diameter of about 0.230". The tubular
sheath 128 is provided at its proximal end with a manifold 134,
having a hemostatic valve 136 thereon and access ports such as for
the infusion of drugs or contrast media as will be understood by
those of skill in the art.
[0080] The outer tubular sheath 128 has an axial length within the
range of from about 30" to about 40", and, in one embodiment of the
deployment device 120 having an overall length of 105 cm, the axial
length of the outer tubular sheath 128 is about 46 cm and the
outside diameter is no more than about 0.250". Thus, the distal end
of the tubular sheath 128 is located at least about 16 cm
proximally of the distal end 126 of the deployment catheter 120 in
stent loaded configuration.
[0081] As can be seen from FIGS. 14-16, proximal retraction of the
outer sheath 128 with respect to the intermediate tube 130 will
expose the compressed iliac branches of the graft, as will be
discussed in more detail below.
[0082] A distal segment of the deployment catheter 120 comprises an
outer tubular housing 138, which terminates distally in an elongate
flexible tapered distal tip 140. The distal housing 138 and tip 140
are axially immovably connected to the central core 132 at a
connection 142.
[0083] The distal tip 140 preferably tapers from an outside
diameter of about 0.225" at its proximal end to an outside diameter
of about 0.070" at the distal end thereof. The overall length of
the distal tip 140 in one embodiment of the deployment catheter 120
is about 3". However, the length and rate of taper of the distal
tip 140 can be varied depending upon the desired trackability and
flexibility characteristics. The distal end of the housing 138 is
secured to the proximal end of the distal tip 140 such as by
thermal bonding, adhesive bonding, and/or any of a variety of other
securing techniques known in the art. The proximal end of distal
tip 140 is preferably also directly or indirectly connected to the
central core 132 such as by a friction fit and/or adhesive
bonding.
[0084] In at least the distal section of the catheter, the central
core 132 preferably comprises a length of hypodermic needle tubing.
The hypodermic needle tubing may extend throughout the length
catheter to the proximal end thereof, or may be secured to the
distal end of a proximal extrusion as illustrated for example in
FIG. 22. A central guidewire lumen 144 extends throughout the
length of the tubular central core 132, having a distal exit port
146 and a proximal access port 148 as will be understood by those
of skill in the art.
[0085] Referring to FIGS. 14-16, a bifurcated endoluminal graft 150
is illustrated in a compressed configuration within the deployment
catheter 120. The graft 150 comprises a distal aortic section 152,
a proximal ipsilateral iliac portion 154, and a proximal
contralateral iliac portion 156. The aortic trunk portion 152 of
the graft 150 is contained within the tubular housing 138. Distal
axial advancement of the central tubular core 132 will cause the
distal tip 140 and housing 138 to advance distally with respect to
the graft 150, thereby permitting the aortic trunk portion 152 of
the graft 150 to expand to its larger, unconstrained diameter.
Distal travel of the graft 150 is prevented by a distal stop 158
which is axially immovably connected to the intermediate tube 130.
Distal stop 158 may comprise any of a variety of structures, such
as an annular flange or component which is adhered to, bonded to or
integrally formed with a tubular extension 160 of the intermediate
tube 132. Tubular extension 160 is axially movably positioned over
the hypotube central core 132.
[0086] The tubular extension 160 extends axially throughout the
length of the graft 150. At the proximal end of the graft 150, a
step 159 axially immovably connects the tubular extension 160 to
the intermediate tube 130. In addition, the step 159 provides a
proximal stop surface to prevent proximal travel of the graft 150
on the catheter 120. The function of step 159 can be accomplished
through any of a variety of structures as will be apparent to those
of skill in the art in view of the disclosure herein. For example,
the step 159 may comprise an annular ring or spacer which receives
the tubular extension 160 at a central aperture therethrough, and
fits within the distal end of the intermediate tube 130.
Alternatively, the intermediate tube 130 can be reduced in diameter
through a generally conical section or shoulder to the diameter of
tubular extension 160.
[0087] Proximal retraction of the outer sheath 128 will release the
iliac branches 154 and 156 of the graft 150. The iliac branches 154
and 156 will remain compressed, within a first (ipsilateral)
tubular sheath 162 and a second (contralateral) tubular sheath 164.
The first tubular sheath 162 is configured to restrain the
ipsilateral branch of the graft 150 in the constrained
configuration, for implantation at the treatment site. The first
tubular sheath 162 is adapted to be axially proximally removed from
the iliac branch, thereby permitting the branch to expand to its
implanted configuration. In one embodiment, the first tubular
sheath 162 comprises a thin walled PTFE extrusion having an outside
diameter of about 0.215" and an axial length of about 7.5 cm. A
proximal end of the tubular sheath 162 is necked down such as by
heat shrinking to secure the first tubular sheath 162 to the
tubular extension 160. In this manner, proximal withdrawal of the
intermediate tube 130 will in turn proximally advance the first
tubular sheath 162 relative to the graft 150, thereby deploying the
self expandable iliac branch of the graft 150.
[0088] The second tubular sheath 164 is secured to the
contralateral guidewire 166 (equivalent to guidewire 66 discussed
previously), which extends outside of the tubular body 122 at a
point 168, such as may be conveniently provided at the junction
between the outer tubular sheath 128 and the distal housing 138.
The second tubular sheath 164 is adapted to restrain the
contralateral branch of the graft 150 in the reduced profile. In
one embodiment of the invention, the second tubular sheath 164 has
an outside diameter of about 0.215" and an axial length of about
7.5 cm. The second tubular sheath 164 can have a significantly
smaller cross-section than the first tubular sheath 162, due to the
presence of the tubular core 132 and intermediate tube 130 within
the first iliac branch 154.
[0089] The second tubular sheath 164 is secured at its proximal end
to a distal end of the contralateral guidewire 166. This may be
accomplished through any of a variety of securing techniques, such
as heat shrinking, adhesives, mechanical interfit and the like. In
one embodiment, the guidewire is provided with a knot or other
diameter enlarging structure to provide an interference fit with
the proximal end of the second tubular sheath 156, and the proximal
end of the second tubular sheath 156 is heat shrunk and/or bonded
in the area of the knot to provide a secure connection. Any of a
variety of other techniques for providing a secure connection
between the contralateral guidewire 166 and tubular sheath 156 can
readily be used in the context of the present invention as will be
apparent to those of skill in the art in view of the disclosure
herein. The contralateral guidewire 166 can comprise any of a
variety of structures, including polymeric monofilament materials,
braided or woven materials, metal ribbon or wire, or conventional
guidewires as are well known in the art.
[0090] In use, the free end of the contralateral guidewire 166 is
advanced through the first lumen 28 of a dual lumen catheter 20 as
has been discussed.
[0091] The deployment catheter 120 is thereafter percutaneously
inserted into the first puncture, and advanced along guidewire 56
(e.g. 0.035 inch) through the ipsilateral iliac and into the aorta.
As the deployment catheter 120 is transluminally advanced, slack
produced in the contralateral guidewire 166 is taken up by
proximally withdrawing the guidewire 166 from the second
percutaneous access site. In this manner, the deployment catheter
120 is positioned in the manner generally illustrated in FIG. 17.
Referring to FIG. 18, the outer sheath 128 is proximally withdrawn
while maintaining the axial position of the overall deployment
catheter 120, thereby releasing the first and second iliac branches
of the graft 150. Proximal advancement of the deployment catheter
120 and contralateral guidewire 166 can then be accomplished, to
position the iliac branches of the graft 150 within the iliac
arteries as illustrated.
[0092] Referring to FIG. 19, the central cote 132 is distally
advanced thereby distally advancing the distal housing 138. This
exposes the aortic trunk 152 of the graft 150, which deploys into
its fully expanded configuration within the aorta. As illustrated
in FIG. 20, the contralateral guidewire 166 is thereafter
proximally withdrawn, thereby by proximally withdrawing the second
sheath 164 from the contralateral iliac branch 156 of the graft
150. The contralateral branch 156 of the graft 150 thereafter self
expands to fit within the iliac artery. The guidewire 166 and
sheath 164 may thereafter be proximally withdrawn and removed from
the patient, by way of the second percutaneous access site.
[0093] Thereafter, the deployment catheter 120 may be proximally
withdrawn to release the ipsilateral branch 154 of the graft 150
from the first tubular sheath 162 as shown in FIG. 21. Following
deployment of the ipsilateral branch 154 of the prosthesis 150, a
central lumen through the aortic trunk 152 and ipsilateral branch
154 is sufficiently large to permit proximal retraction of the
deployment catheter 120 through the deployed bifurcated graft 150.
The deployment catheter 120 may thereafter be proximally withdrawn
from the patient by way of the first percutaneous access site.
[0094] While a number of preferred embodiments of the invention and
variations thereof have been described in detail, other
modifications and methods of using and medical applications for the
same will be apparent to those of skill in the art. Accordingly, it
should be understood that various applications, modifications, and
substitutions may be made of equivalents without departing from the
spirit of the invention or the scope of the claims.
* * * * *