U.S. patent application number 09/852226 was filed with the patent office on 2002-02-21 for bifurcated stent delivery system having retractable sheath.
Invention is credited to Wilson, W. Stan.
Application Number | 20020022874 09/852226 |
Document ID | / |
Family ID | 23822995 |
Filed Date | 2002-02-21 |
United States Patent
Application |
20020022874 |
Kind Code |
A1 |
Wilson, W. Stan |
February 21, 2002 |
BIFURCATED STENT DELIVERY SYSTEM HAVING RETRACTABLE SHEATH
Abstract
An improved catheter assembly and method are provided for
treating bifurcated vessels. The catheter assembly of the present
invention includes a tubular sheath for restraining dual balloons
normally biased apart. Withdrawal of the sheath allows the balloons
to separate and deploy intravascular stents in a bifurcated vessel.
The catheter assembly also includes the feature of containing two
guide wire lumens in a single catheter designed to track over a
single wire prior to arrival at the bifurcation, thus preventing
wire wrapping and crossing of the wires.
Inventors: |
Wilson, W. Stan; (Missoula,
MT) |
Correspondence
Address: |
FULWIDER PATTON LEE & UTECHT, LLP
HOWARD HUGHES CENTER
6060 CENTER DRIVE
TENTH FLOOR
LOS ANGELES
CA
90045
US
|
Family ID: |
23822995 |
Appl. No.: |
09/852226 |
Filed: |
May 8, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09852226 |
May 8, 2001 |
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09459004 |
Dec 10, 1999 |
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6254593 |
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Current U.S.
Class: |
623/1.11 |
Current CPC
Class: |
A61F 2/856 20130101;
A61F 2002/065 20130101; A61F 2/954 20130101; A61F 2250/006
20130101; A61F 2/958 20130101 |
Class at
Publication: |
623/1.11 |
International
Class: |
A61F 002/06 |
Claims
What is claimed is:
1. A stent delivery assembly for treating bifurcated vessels,
comprising: a dual balloon Y-shaped catheter having a proximal end
and a distal end, the catheter including a first expandable member
having a proximal end and a distal end, the catheter further
including a second expandable member having a proximal end and a
distal end; a first guide wire lumen for receiving a first guide
wire, the first guide wire lumen extending through at least a
portion of the catheter including the first expandable member; a
second guide wire lumen for receiving a second guide wire, the
second guide wire lumen extending through at least a portion of the
catheter including the second expandable member; and a tubular
member; wherein the first expandable member and the second
expandable member are normally biased apart, but are restrained and
releasably held together by the tubular member to provide a low
profile during delivery of a Y-shaped stent.
2. The assembly of claim 1, wherein the tubular member is a
sheath.
3. The assembly of claim 1, wherein the Y-shaped stent is removably
mounted on the first and second expandable members.
4. The assembly of claim 1, further including an inflation lumen
for inflating the first and second expandable members.
5. The assembly of claim 4, wherein the first and second expandable
members inflate simultaneously.
6. The assembly of claim 1, wherein the second expandable member is
longer than the first expandable member.
7. The assembly of claim 6, wherein when the first expandable
member and the second expandable member are restrained and held
together by the tubular member, a distal portion of the second
expandable member protrudes from a distal end of the tubular
member.
8. A method of stenting a bifurcated vessel having a bifurcation, a
first vessel branch, and a second vessel branch, comprising the
steps of: providing a dual balloon Y-shaped catheter having a first
expandable member and a second expandable member; providing a
Y-shaped stent mounted on the first and second expandable members;
providing a tubular member and placing it about the first and
second expandable members such that the first and second expandable
members are normally biased apart, but are restrained and held
together by the tubular member; delivering the Y-shaped stent to a
target area; withdrawing the tubular member proximally until the
first expandable member and the second expandable member are
released and spring apart; implanting the Y-shaped stent by
inflating the first and second expandable members; deflating the
first and second expandable members; and withdrawing the
catheter.
9. The method of claim 8, wherein the tubular member is a
sheath.
10. A method of stenting a bifurcated vessel having a bifurcation,
a first vessel branch, and a second vessel branch, comprising the
steps of: providing a dual balloon Y-shaped catheter having a
proximal end and a distal end, the catheter including a first
expandable member having a proximal end and a distal end, the
catheter further including a second expandable member having a
proximal end and a distal end; providing a first guide wire lumen
for receiving a first guide wire, the first guide wire lumen
extending through at least a portion of the catheter including the
first expandable member; providing a second guide wire lumen for
receiving a second guide wire, the second guide wire lumen
extending through at least a portion of the catheter including the
second expandable member; providing a Y-shaped stent mounted on the
first and second expandable members; providing a tubular member and
placing it about the first and second expandable members such that
the first and second expandable members are normally biased apart,
but are restrained and held together by the tubular member;
providing a second guide wire and positioning the second guide wire
distally of the bifurcation in the first vessel branch; loading the
second guide wire into the second guide wire lumen; advancing the
catheter and tubular member over the second guide wire so that the
catheter is advanced distally of the bifurcation in the first
vessel branch; withdrawing the tubular member proximally until the
first expandable member and the second expandable member are
released and spring apart; withdrawing the catheter proximally to a
position proximal of the bifurcation; providing a first guide wire;
advancing the first guide wire out of the first guide wire lumen
and into the second vessel branch distally of the bifurcation;
advancing the catheter distally over the first and second guide
wires until the Y-shaped stent is positioned at the bifurcation;
implanting the Y-shaped stent by inflating the first and second
expandable members; deflating the first and second expandable
members; and withdrawing the catheter.
11. The method of claim 10, wherein the tubular member is a
sheath.
12. A method of stenting a bifurcated vessel having a bifurcation,
a first vessel branch, and a second vessel branch, comprising the
steps of: providing a dual balloon Y-shaped catheter having a
proximal end and a distal end, the catheter including a first
expandable member having a proximal end and a distal end, the
catheter further including a second expandable member having a
proximal end and a distal end; providing a first guide wire lumen
for receiving a first guide wire, the first guide wire lumen
extending through at least a portion of the catheter including the
first expandable member; providing a second guide wire lumen for
receiving a second guide wire, the second guide wire lumen
extending through at least a portion of the catheter including the
second expandable member; providing a Y-shaped stent mounted on the
first and second expandable members; providing a tubular member and
placing it about the first and second expandable members such that
the first and second expandable members are normally biased apart,
but are restrained and held together by the tubular member;
providing a second guide wire and positioning the second guide wire
distally of the bifurcation in the first vessel branch; loading the
second guide wire into the second guide wire lumen; advancing the
catheter and tubular member over the second guide wire so that the
catheter is advanced proximally of the bifurcation in the first
vessel branch; withdrawing the tubular member proximally until the
first expandable member and the second expandable member are
released and spring apart; providing a first guide wire; advancing
the first guide wire out of the first guide wire lumen and into the
second vessel branch distal of the bifurcation; advancing the
catheter distally over the first and second guide wires until the
Y-shaped stent is positioned at the bifurcation; implanting the
Y-shaped stent by inflating the first and second expandable
members; deflating the first and second expandable members; and
withdrawing the catheter.
13. The method of claim 12, wherein the tubular member is a sheath.
Description
BACKGROUND OF THE INVENTION
[0001] The invention relates to a stent delivery system for use at
a bifurcation and, more particularly, a bifurcated stent delivery
system having a retractable sheath.
[0002] Stents conventionally repair blood vessels that are
diseased. Stents are generally hollow and cylindrical in shape and
have terminal ends that are generally perpendicular to their
longitudinal axes. In use, the conventional stent is positioned at
the diseased area of a vessel and, after placement, the stent
provides an unobstructed pathway for blood flow.
[0003] Repair of vessels that are diseased at a bifurcation is
particularly challenging since the stent must overlay the entire
diseased area at the bifurcation, yet not itself compromise blood
flow. Therefore, the stent must, without compromising blood flow,
overlay the entire circumference of the ostium to a diseased
portion and extend to a point within and beyond the diseased
portion. Where the stent does not overlay the entire circumference
of the ostium to the diseased portion, the stent fails to
completely repair the bifurcated vessel. Where the stent overlays
the entire circumference of the ostium to the diseased portion, yet
extends into the junction comprising the bifurcation, the diseased
area is repaired, but blood flow may be compromised in other
portions of the bifurcation. Unopposed stent elements may promote
lumen compromise during neointimalization and healing, producing
restenosis and requiring further procedures. Moreover, by extending
into the junction comprising the bifurcation, the stent may block
access to portions of the bifurcated vessel that require
performance of further interventional procedures. Similar problems
are encountered when vessels are diseased at their angled origin
from the aorta as in the ostium of a right coronary or a vein
graft. In this circumstance, a stent overlaying the entire
circumference of the ostium extends back into the aorta, creating
problems, including those for repeat catheter access to the vessel
involved in further interventional procedures.
[0004] Conventional stents are designed to repair areas of blood
vessels that are removed from bifurcations and, since a
conventional stent generally terminates at right angles to its
longitudinal axis, the use of conventional stents in the region of
a vessel bifurcation may result in blocking blood flow of a side
branch or fail to repair the bifurcation to the fullest extent
necessary. The conventional stent might be placed so that a portion
of the stent extends into the pathway of blood flow to a side
branch of the bifurcation or extend so far as to completely cover
the path of blood flow in a side branch. The conventional stent
might alternatively be placed proximal to, but not entirely
overlaying, the circumference of the ostium to the diseased
portion. Such a position of the conventional stent results in a
bifurcation that is not completely repaired. The only conceivable
situation in which the conventional stent, having right-angled
terminal ends, could be placed where the entire circumference of
the ostium is repaired without compromising blood flow, is where
the bifurcation is formed of right angles. In such scenarios,
extremely precise positioning of the conventional stent is
required. This extremely precise positioning of the conventional
stent may result with the right-angled terminal ends of the
conventional stent overlaying the entire circumference of the
ostium to the diseased portion without extending into a side
branch, thereby completely repairing the right-angled
bifurcation.
[0005] To circumvent or overcome the problems and limitations
associated with conventional stents in the context of repairing
diseased bifurcated vessels, a stent that consistently overlays the
entire circumference of the ostium to a diseased portion, yet does
not extend into the junction comprising the bifurcation, may be
employed. Such a stent would have the advantage of completely
repairing the vessel at the bifurcation without obstructing blood
flow in other portions of the bifurcation. In addition, such a
stent would allow access to all portions of the bifurcated vessel
should further interventional treatment be necessary. In a
situation involving disease in the origin of an angulated
aorto-ostial vessel, such a stent would have the advantage of
completely repairing the vessel origin without protruding into the
aorta or complicating repeat access.
[0006] In addition to the problems encountered by using the prior
art stents to treat bifurcations, the delivery platform for
implanting such stents has presented numerous problems. For
example, a conventional stent is implanted in the main vessel so
that a portion of the stent is across the side branch, so that
stenting of the side branch must occur through the main-vessel
stent struts. In this method, commonly referred to in the art as
the "monoclonal antibody" approach, the main-vessel stent struts
must be spread apart to form an opening to the side branch vessel
and then a catheter with a stent is delivered through the opening.
The cell to be spread apart must be randomly and blindly selected
by recrossing the deployed stent with a wire. The drawback with
this approach is there is no way to determine or guarantee that the
main-vessel stent struts are properly oriented with respect to the
side branch or that the appropriate cell has been selected by the
wire for dilatation. The aperture created often does not provide a
clear opening and creates a major distortion in the surrounding
stent struts. There is no way to tell if the main-vessel stent
struts have been properly oriented and spread apart to provide a
clear opening for stenting the side branch vessel.
[0007] In another prior art method for treating bifurcated vessels,
commonly referred to as the "Culotte technique," the side branch
vessel is first stented so that the stent protrudes into the main
vessel. A dilatation is then performed in the main vessel to open
and stretch the stent struts extending across the lumen from the
side branch vessel. Thereafter, the main-vessel stent is implanted
so that its proximal end overlaps with the side branch vessel. One
of the drawbacks of this approach is that the orientation of the
stent elements protruding from the side branch vessel into the main
vessel is completely random. Furthermore, the deployed stent must
be recrossed with a wire blindly and arbitrarily selecting a
particular stent cell. When dilating the main vessel stretching the
stent struts is therefore random, leaving the possibility of
restricted access, incomplete lumen dilatation, and major stent
distortion.
[0008] In another prior art device and method of implanting stents,
a "T" stent procedure includes implanting a stent in the side
branch ostium of the bifurcation followed by stenting the main
vessel across the side branch ostium. In another prior art
procedure, known as "kissing" stents, a stent is implanted in the
main vessel with a side branch stent partially extending into the
main vessel creating a double-barreled lumen of the two stents in
the main vessel proximal to the bifurcation. Another prior art
approach includes a so-called "trouser legs and seat" approach,
which includes implanting three stents, one stent in the side
branch vessel, a second stent in a distal portion of the main
vessel, and a third stent, or a proximal stent, in the main vessel
just proximal to the bifurcation.
[0009] All of the foregoing stent deployment assemblies suffer from
the same problems and limitations. Typically, there are uncovered
intimal surface segments on the main vessel and side branch vessels
between the stented segments. An uncovered flap or fold in the
intima or plaque will invite a "snowplow" effect, representing a
substantial risk for subacute thrombosis, and the increased risk of
the development of restenosis. Further, where portions of the stent
are left unopposed within the lumen, the risk for subacute
thrombosis or the development of restenosis again is increased. The
prior art stents and delivery assemblies for treating bifurcations
are difficult to use, making successful placement nearly
impossible. Further, even where placement has been successful, the
side branch vessel can be "jailed" or covered so that there is
impaired access to the stented area for subsequent
intervention.
[0010] Attempts to bring any device, such as a bifurcated stent on
a bifurcated balloon assembly, to a bifurcation over two wires are
prone to the problem of wire wrapping. This phenomenon involves one
wire crossing the other first anteriorly then posteriorly. The
resulting wrapping then creates resistance to advancement of the
device, thus resulting in failure of deployment. Therefore, when
delivering a device ultimately utilizing two wires, it would be
desirable to first track the device in over a single wire, thus
avoiding wire wrapping. The present invention offers a solution to
these problems and others.
[0011] As used herein, the terms "proximal," "proximally," and
"proximal direction" when used with respect to the invention are
intended to mean moving away from or out of the patient, and the
terms "distal," "distally," and "distal direction" when used with
respect to the invention are intended to mean moving toward or into
the patient. These definitions will apply with reference to
apparatus, such as catheters, guide wires, stents, the like. When
used with reference to body lumens, such as blood vessels and the
like, the terms "proximal," "proximally," and "proximal direction"
are intended to mean toward the heart; and the terms "distal,"
"distally," and "distal direction" are intended to mean away from
the heart, and particularly with respect to a bifurcated blood
vessel, are intended to mean in the direction in which the
branching occurs.
SUMMARY OF THE INVENTION
[0012] The invention provides for a bifurcated stent delivery
system having a retractable sheath. The system is designed for
repairing a main vessel and a side branch vessel forming a
bifurcation, without compromising blood flow in other portions of
the bifurcation, thereby allowing access to all portions of the
bifurcated vessel should further interventional treatment be
necessary. The catheter and the retractable sheath are designed to
reduce the likelihood of wire wrapping during the stenting
procedure.
[0013] In one aspect of the invention, there is provided a stent
delivery assembly for treating bifurcated vessels including a dual
balloon Y-shaped catheter. The catheter includes a first expandable
member and a second expandable member. A first guide wire lumen is
provided for receiving a first guide wire. The first guide wire
lumen extends through at least a portion of the catheter including
the first expandable member. A second guide wire lumen is provided
for receiving a second guide wire, the second guide wire lumen
extends through at least a portion of the catheter including the
second expandable member. A tubular member is provided, wherein the
first expandable member and the second expandable member are
normally biased apart, but are restrained and held together by the
tubular member to provide a low profile during delivery of a
Y-shaped stent.
[0014] In another aspect of the invention, a method is provided of
stenting a bifurcated vessel having a bifurcation, a first vessel
branch, and a second vessel branch. The method includes the step of
providing a dual balloon Y-shaped catheter having a first
expandable member and a second expandable member. A Y-shaped stent
is mounted on the first and second expandable members. A tubular
member is placed about the first and second expandable members such
that the first and second expandable members are normally biased
apart, but are restrained and held together by the tubular member.
The Y-shaped stent is then delivered to a target area. The tubular
member is withdrawn proximally until the first expandable member
and the second expandable member are released and spring apart. The
Y-shaped stent is next implanted by inflating the first and second
expandable members. The first and second expandable members are
then deflated and the catheter is withdrawn.
[0015] In yet another aspect of the invention, a method is provided
of stenting a bifurcated vessel having a bifurcation, a first
vessel branch, and a second vessel branch. The method includes the
step of providing a dual balloon Y-shaped catheter including a
first expandable member and a second expandable member. A first
guide wire lumen is provided for receiving a first guide wire. The
first guide wire lumen extends through at least a portion of the
catheter including the first expandable member. A second guide wire
lumen is provided for receiving a second guide wire. The second
guide wire lumen extends through at least a portion of the catheter
including the second expandable member. A Y-shaped stent is mounted
on the first and second expandable members. A tubular member is
placed about the first and second expandable members such that the
first and second expandable members are normally biased apart, but
are restrained and held together by the tubular member. A second
guide wire is positioned distally of the bifurcation in the first
vessel branch. The second guide wire is then backloaded into the
second guide wire lumen. Next, the catheter and tubular member are
advanced over the second guide wire so that the catheter is
advanced distally of the bifurcation in the first vessel branch.
Alternatively, the catheter can be advanced proximally of the
bifurcation in the first vessel branch. The tubular member is
withdrawn proximally until the first expandable member and the
second expandable member are released and spring apart. Next, the
catheter is withdrawn proximally to a position proximal of the
bifurcation. A first guide wire is provided and advanced out of the
first guide wire lumen and into the second vessel branch distally
of the bifurcation. The catheter is advanced distally over the
first and second guide wires until the Y-shaped stent is positioned
at the bifurcation. The Y-shaped stent is then implanted by
inflating the first and second expandable members. The first and
second expandable members are deflated and the catheter and guide
wires are withdrawn.
[0016] Other features and advantages of the present invention will
become apparent from the following detailed description, taken in
conjunction with the accompanying drawings, which illustrate, by
way of example, the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is an elevational view of a bifurcation in which a
prior art "T" stent is in a side branch ostium followed by the
stenting of the main vessel across the branch ostium.
[0018] FIG. 2 is an elevational view of a bifurcation in which
"touching" prior art stents are depicted in which one stent is
implanted in the side branch, a second stent implanted in a distal
portion of the main vessel next to the branch stent, with
interrupted placement of a third stent implanted more proximally in
the main vessel.
[0019] FIG. 3 is an elevational view of a bifurcation depicting
"kissing" stents where a portion of one stent is implanted in both
the side branch and the main vessel and adjacent to a second stent
implanted in the main vessel creating a double-barreled lumen in
the main vessel proximal to the bifurcation.
[0020] FIG. 4 is an elevational view of a prior art "trouser legs
and seat" stenting approach depicting one stent implanted in the
side branch vessel, a second stent implanted in a proximal portion
of the main vessel, and a close deployment of a third stent distal
to the bifurcation leaving a small gap between the three stents of
an uncovered lumenal area.
[0021] FIG. 5A is an elevational view of a bifurcation in which a
prior art stent is implanted in the side branch vessel.
[0022] FIG. 5B is an elevational view of a bifurcation in which a
prior art stent is implanted in the side branch vessel, with the
proximal end of the stent extending into the main vessel.
[0023] FIG. 6 is an elevational view, partially in section,
depicting an embodiment in which a Y-shaped catheter assembly
deploys a Y-shaped stent in a bifurcation.
[0024] FIG. 7 is an elevational view depicting the Y-shaped
catheter assembly of FIG. 6 in which the stent is mounted on the
expandable members of the catheter.
[0025] FIG. 8 is a perspective view of the assembly of FIG. 7 shown
partially inserted into the sheath.
[0026] FIG. 9 is an elevational view, partially in section, of a
bifurcation in which the catheter of FIG. 7 is delivering the stent
in the bifurcated area with the catheter inserted into the
sheath.
[0027] FIG. 10 is an elevational view, partially in section, of a
bifurcation in which the catheter of FIG. 7 is delivering the stent
in the bifurcated area with the sheath being withdrawn
proximally.
[0028] FIG. 11 is an elevational view, partially in section, of a
bifurcation in which the catheter of FIG. 7 has been withdrawn
proximally of the bifurcation and a guide wire is being extended
into the second vessel branch.
[0029] FIG. 12 is an elevational view, partially in section, of a
bifurcation in which the catheter of FIG. 7 is implanted at the
bifurcation.
[0030] FIG. 13 is another embodiment of the dual balloon Y-shaped
catheter.
[0031] FIG. 14 is an elevational view, partially in section, of the
dual balloon Y-shaped catheter of FIG. 13 restrained by the
sheath.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0032] As shown in the exemplary drawings wherein like reference
numerals indicate like or corresponding elements among the figures,
the present invention includes a bifurcated stent delivery system
for treating bifurcated vessels in, for example, the coronary
arteries, veins, arteries, and other vessels in the body.
[0033] Prior art attempts at implanting intravascular stents in a
bifurcation have proved less than satisfactory. For example, FIGS.
1-4 depict prior art devices which include multiple stents being
implanted in both the main vessel and a side branch vessel. In FIG.
1, a prior art "T" stent is implanted such that a first stent is
implanted in the side branch near the ostium of the bifurcation,
and a second stent is implanted in the main vessel, across the side
branch ostium. With this approach, portions of the side branch
vessel are left uncovered, and blood flow to the side branch vessel
must necessarily pass through the main vessel stent, causing
possible obstructions or thrombosis.
[0034] Referring to FIG. 2, three prior art stents are required to
stent the bifurcation. In FIG. 3, the prior art method includes
implanting two stents side by side, such that one stent extends
into the side branch vessel and the main vessel, and the second
stent is implanted in the main vessel. This results in a
double-barreled lumen which can present problems such as
thrombosis, and turbulence in blood flow. Referring to the FIG. 4
prior art device, a first stent is implanted in the side branch
vessel, a second stent is implanted in a proximal portion of the
main vessel, and a third stent is implanted distal to the
bifurcation, thereby leaving a small gap between the stents and an
uncovered lumenal area.
[0035] Referring to FIGS. 5A and 5B, a prior art stent is
configured for deployment in side branch vessel 5. In treating side
branch vessel 5, if a prior art stent is used, a condition as
depicted will occur. That is, a stent deployed in side branch
vessel 5 will leave a portion of the side branch vessel exposed, or
as depicted in 5B, a portion of the stent will extend into main
vessel 6.
[0036] Turning to FIGS. 6-12, in one embodiment of the present
invention, stent delivery assembly 10 is provided for treating
bifurcated vessels. In this embodiment, a Y-shaped stent is
implanted to cover the bifurcation. Catheter 12 can be configured
as a dual balloon Y-shaped catheter having a proximal end and a
distal end. The catheter includes first expandable member 14 and
second expandable member 16 that are configured to reside
side-by-side (Y-shaped) for low profile delivery and to spring
apart for implanting Y-shaped stent 18. Each of the expandable
members has a proximal end and a distal end. The stent is removably
mounted on the first and second expandable members.
[0037] A first guide wire lumen 20 is provided for receiving first
guide wire 22. The first guide wire lumen extends through at least
a portion of catheter 12 including first expandable member 14. A
second guide wire lumen 24 is provided for receiving second guide
wire 26. The second guide wire lumen extends through at least a
portion of the catheter including second expandable member 16. The
expandable members can be inflatable non-distensible balloons. The
guide wires 22, 26 preferably are stiff wires each having a
diameter of 0.014 inch, but can have different diameters and
degrees of stiffness as required for a particular application. A
particularly suitable guide wire can include those manufactured and
sold under the tradenames Sport.RTM. and Ironman.RTM., manufactured
by Advanced Cardiovascular Systems, Incorporated, Santa Clara,
Calif.
[0038] A tubular member, such as sheath 28, is provided, wherein
the first expandable member and the second expandable member are
normally biased apart, but are restrained and held together by the
sheath to provide a low profile during delivery of Y-shaped stent
18. The sheath can be formed from a polymer such as polyethylene,
polyurethane, and nylons, although other similar polymeric material
may also be suitable, such as polyetheretherketone (PEEK),
polytetrafluoroethylene (PTFE), polyethylene terephthalate (PET),
and the like. Other suitable materials can be used as are known to
those skilled in the art.
[0039] The catheter 12 further includes an inflation lumen (not
shown) for inflating first and second expandable members 14, 16
simultaneously. The expandable members can be inflated by
delivering a suitable inflation media, such as saline, to the
expandable members via the inflation lumen. In one embodiment, the
second expandable member is longer than the first expandable member
so that distal portion 30 of the second expandable member protrudes
from sheath 28 during delivery to facilitate tracking.
[0040] In one method of stenting a bifurcated vessel, as shown in
FIGS. 9-12, Y-shaped stent 18 is mounted on first and second
expandable members 14, 16. The second guide wire 26 is positioned
distal of the bifurcation in first vessel branch 6. The second
guide wire is then back loaded into second guide wire lumen 24. The
catheter 12 and sheath 28 are advanced over the second guide wire
so that the catheter is advanced distally of the bifurcation in the
first vessel branch. During the advancement of the catheter, the
first and second expandable members are restrained and held
together by sheath. Consequently, the sheath helps to provide a low
profile during delivery of the stent.
[0041] In keeping with the invention, sheath 28 is withdrawn
proximally until first expandable member 14 and second expandable
member 16 are released and spring apart. The catheter 12 is then
withdrawn proximally to a position proximal of the bifurcation. In
one embodiment, first guide wire 22 has been contained as an
integrated guide wire within first guide wire lumen 20 up to this
point. Alternatively, the first guide wire may be inserted into the
proximal end of the first guide wire lumen at this time. The first
guide wire is then advanced out of the first guide wire lumen and
into second vessel branch 5 distally of the bifurcation.
[0042] If, after withdrawal of the sheath to release the expandable
members, the device is seen to be oriented such that first
expandable member 14 is further away from vessel than is second
expandable member 16, it may be desirable to withdraw second guide
wire 26 and readvance it into vessel 5 with first guide wire 22
then advanced into vessel 6. This reassignment of wires permits
avoidance of rotation of more than 90 degrees. In situations in
which there is concern about recrossing of the lumen of the side
branch vessel with either wire, this wire reassignment is performed
before catheter 12 is withdrawn proximal to the bifurcation.
[0043] The Y-shaped stent 18 is implanted by advancing distally
over first and second guide wires 22, 26 until the stent is
positioned at the bifurcation in apposition with carina 32. Due to
the appropriate wire selection, rotation of no more than 90 degrees
will be required. The stent is implanted by inflating first and
second expandable members 14, 16, which are designed to inflate
simultaneously. Then the first and second expandable members are
deflated and the catheter and guide wires can be withdrawn from the
patient's vasculature. The novel arrangement of sheath 28 and guide
wires 22, 26 and their respective lumens permit single unit
transport of a Y-shaped stent to the distal target site without
wire wrapping problems and it allows for minimal requirements of
rotation of the device (less than 90 degrees) for optimal
deployment (allowing minimal twist deformity).
[0044] In a related method, Y-shaped stent 18 is mounted on first
and second expandable members 14, 16. The second guide wire 26 is
positioned distal of the bifurcation in first vessel branch 6. The
second guide wire is then back loaded into second guide wire lumen
24. The catheter 12 and sheath 28 are advanced over the second
guide wire so that the catheter is advanced proximally of the
bifurcation in the first vessel branch. During the advancement of
the catheter, the first and second expandable members are
restrained and held together by the sheath. Consequently, the
sheath helps to provide a low profile during delivery of the
stent.
[0045] In keeping with the invention, sheath 28 is withdrawn
proximally until first expandable member 14 and second expandable
member 16 are released and spring apart. In one embodiment, first
guide wire 22 has been contained as an integrated guide wire within
first guide wire lumen 20 up to this point. Alternatively, the
first guide wire may be inserted into the proximal end of the first
guide wire lumen at this time. The first guide wire is then
advanced out of the first guide wire lumen and into second vessel
branch 5 distally of the bifurcation.
[0046] Next, catheter is advanced distally over first and second
guide wires 22, 26 until Y-shaped stent 18 is positioned at the
bifurcation in apposition with carina 32. Due to the appropriate
wire selection, rotation of no more than 90 degrees will be
required. The stent is implanted by inflating first and second
expandable members 14, 16, which are designed to inflate
simultaneously. Then the first and second expandable members are
deflated and the catheter and guide wires can be withdrawn from the
patient's vasculature. The novel arrangement of sheath 28 and guide
wires 22, 26 and their respective lumens permit single unit
transport of a Y-shaped stent to the distal target site without
wire wrapping problems and it allows for minimal requirements of
rotation of the device (less than 90 degrees) for optimal
deployment (allowing minimal twist deformity).
[0047] Notably, it is contemplated that the methods of the present
invention can be accomplished with any suitable catheter 12.
Referring to FIGS. 13 and 14, another embodiment of the dual
balloon Y-shaped catheter is depicted. The catheter has first stem
40 and second stem 42. The first stem 40 is connected to first
expandable member 14. The second stem 42 is connected to second
expandable member 16 having distal portion 30 for tracking. In this
embodiment, the second expandable member is approximately twice as
long as the first expandable member; however, it is contemplated
that the expandable members can be of varying lengths. The
expandable members can be simultaneously inflated via an inflation
lumen (not shown). The first guide wire 22 is positioned within the
first expandable member and the second guide wire is positioned
within the second expandable member. The first and second
expandable members are normally biased apart, but are restrained
and held together by sheath 28 to provide a low profile during
delivery of Y-shaped stent 18.
[0048] While the invention herein has been illustrated and
described in terms of a catheter assembly and method of use, it
will be apparent to those skilled in the art that the invention can
be used in other instances. Other modifications and improvements
may be made without departing from the scope of the invention.
* * * * *