U.S. patent application number 12/955578 was filed with the patent office on 2011-03-24 for cutting member for bifurcation catheter assembly.
This patent application is currently assigned to BOSTON SCIENTIFIC SCIMED, INC.. Invention is credited to Thomas J. Holman, Jan Weber.
Application Number | 20110071559 12/955578 |
Document ID | / |
Family ID | 39734930 |
Filed Date | 2011-03-24 |
United States Patent
Application |
20110071559 |
Kind Code |
A1 |
Holman; Thomas J. ; et
al. |
March 24, 2011 |
Cutting Member for Bifurcation Catheter Assembly
Abstract
A catheter assembly for deployment in a vessel includes a
catheter shaft extending from a proximal end portion to a distal
end portion. A balloon is operatively coupled to the distal end
portion of the catheter shaft. At least one cutting member is
coupled to the catheter assembly. As the balloon is inflated, the
cutting member is moved to a position to cut a portion of the
vessel.
Inventors: |
Holman; Thomas J.;
(Minneapolis, MN) ; Weber; Jan; (Maastricht,
NL) |
Assignee: |
BOSTON SCIENTIFIC SCIMED,
INC.
Maple Grove
MN
|
Family ID: |
39734930 |
Appl. No.: |
12/955578 |
Filed: |
November 29, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11750748 |
May 18, 2007 |
7842056 |
|
|
12955578 |
|
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Current U.S.
Class: |
606/159 ;
604/101.01 |
Current CPC
Class: |
A61M 25/1002 20130101;
A61M 2025/0058 20130101; A61M 2025/1086 20130101; A61B 17/320725
20130101; A61M 2025/1081 20130101; A61M 25/1011 20130101; A61B
2017/22061 20130101; A61M 2025/1045 20130101 |
Class at
Publication: |
606/159 ;
604/101.01 |
International
Class: |
A61B 17/22 20060101
A61B017/22; A61M 29/00 20060101 A61M029/00 |
Claims
1. A catheter assembly for use in a vessel, the catheter assembly
comprising: a catheter shaft extending from a proximal end portion
to a distal end portion; a balloon assembly operatively coupled to
the distal end portion of the catheter shaft; and at least one
cutting member positioned relative to the balloon assembly, wherein
the at least one cutting member includes a first cutting portion
and a second cutting portion, wherein the second cutting portion is
rotatably coupled to the first cutting portion such that when the
balloon assembly is inflated the second cutting portion pivots
relative to the first cutting portion in a direction generally
radially outward from the balloon assembly.
2. The catheter assembly of claim 1, wherein the second cutting
portion is configured to rotate in a direction generally
perpendicular to a longitudinal axis of the catheter shaft.
3. The catheter assembly of claim 1, wherein the first cutting
portion is coupled to the balloon assembly and the second cutting
portion is coupled to the first cutting portion.
4. The catheter assembly of claim 1, wherein the balloon assembly
includes a bulge portion, wherein, as the balloon assembly is
inflated, the bulge portion is configured to contact and pivot the
second cutting portion.
5. The catheter assembly of claim 4, wherein the first cutting
portion is attached to the balloon assembly proximal or distal of
the bulge portion.
6. The catheter assembly of claim 1, wherein the balloon assembly
includes a main balloon and a side balloon, wherein the at least
one cutting member is coupled to the side balloon such that as the
side balloon is inflated the side balloon is configured to contact
and pivot the second cutting portion.
7. The catheter assembly of claim 1, further comprising a sheath
positioned about the balloon assembly, wherein the at least one
cutting member is coupled to the sheath.
8. The catheter assembly of claim 7, wherein the first cutting
portion is coupled to the sheath and the second cutting portion is
coupled to the first cutting portion.
9. The catheter assembly of claim 1, wherein the at least one
cutting member includes a cutting surface being an exposed edge of
the cutting member positioned opposite the balloon assembly.
10. A method for forming a catheter assembly for deployment in a
bifurcated vessel, the method comprising: providing a catheter
shaft extending from a proximal end portion to a distal end
portion; coupling a balloon assembly at the distal end portion of
the catheter shaft; and positioning a cutting member relative to
the balloon assembly, the cutting member including a first cutting
portion and a second cutting portion, the second cutting portion
being rotatably coupled to the first cutting portion, wherein the
cutting member is positioned such that, when the balloon assembly
is inflated, the balloon assembly pivots the second cutting portion
relative to the first cutting member in a direction radially
outward from the balloon assembly
11. The catheter assembly of claim 10, wherein the second cutting
portion is configured to rotate in a direction generally
perpendicular to a longitudinal axis of the catheter shaft.
12. The method of claim 10, wherein positioning the cutting member
includes coupling the cutting member to the balloon assembly.
13. The method of claim 12, wherein the balloon assembly includes a
main balloon and a side balloon, wherein the cutting member is
positioned adjacent to the side balloon such that the side balloon
pivots the second cutting portion of the cutting member when
inflated.
14. The method of claim 12, wherein the balloon assembly includes a
bulge portion, wherein the cutting member is positioned adjacent to
the bulge portion such that when the bulge portion is inflated, the
bulge portion pivots the second cutting portion of the cutting
member.
15. The method of claim 10, further comprising providing a sheath
positioned about the balloon assembly, wherein the cutting member
is coupled to an outer surface of the sheath.
16. The method of claim 15, further comprising defining an aperture
in the sheath through which the balloon assembly extends upon
inflation, wherein the second cutting portion of the cutting member
is positioned to extend over the aperture so that the balloon
assembly contacts and rotates the cutting portion upon
inflation.
17. A catheter assembly for use in a vessel, the catheter assembly
comprising: a catheter shaft extending from a proximal end portion
to a distal end portion; a main balloon coupled to the distal end
portion of the catheter shaft; a side balloon including a proximal
waist and a distal waist, wherein the proximal waist is coupled to
the catheter shaft proximal of the main balloon and the distal
waist is coupled to the catheter shaft distal of the main balloon;
and a first cutting member coupled to the side balloon, wherein the
first cutting member includes a first cutting portion and a second
cutting portion, wherein the second cutting portion is rotatably
coupled to the first cutting portion such that when the side
balloon is inflated the second cutting portion pivots relative to
the first cutting portion.
18. The catheter assembly of claim 17, wherein the second cutting
portion is configured to rotate in a direction generally
perpendicular to a longitudinal axis of the catheter shaft.
19. The catheter assembly of claim 17, wherein the first cutting
portion is coupled to the side balloon and the second cutting
portion is coupled to the first cutting portion.
20. The catheter assembly of claim 17, further comprising a second
cutting member coupled to the side balloon, wherein the second
cutting member includes a first cutting portion and a second
cutting portion, wherein the first cutting portion is coupled to
the side balloon and the second cutting portion is rotatably
coupled to the first cutting portion such that when the side
balloon is inflated the second cutting portion pivots relative to
the first cutting portion.
Description
RELATED APPLICATIONS
[0001] This application is a continuation of co-pending U.S.
application Ser. No. 11/750,748, filed May 18, 2007, the entire
disclosure of which is incorporated herein by reference.
TECHNICAL FIELD
[0002] This disclosure relates to catheter systems and methods for
treating vessel bifurcations.
BACKGROUND
[0003] Catheters are used with stents and balloon inflatable
structures to treat strictures, stenoses, and narrowing in various
parts of the body. Various catheter designs have been developed for
the dilatation of stenoses and to deliver and deploy stents at
treatment sites within the body.
[0004] Stents are typically intraluminally placed by a catheter
within a vein, artery, or other tubular body organ for treating
conditions such as, for example, occlusions, stenoses, aneurysms,
dissection, or weakened, diseased, or abnormally dilated vessel or
vessel wall, by expanding the vessel or by reinforcing the vessel
wall. Once delivered, the stents can be expanded using one or more
inflation members such as balloons. Stents can improve angioplasty
results by preventing elastic recoil and by remodeling of the
vessel wall and treating dissections in blood vessel walls caused
by balloon angioplasty of coronary arteries. Stents can also be
used as a drug delivery medium for treatment of damaged portions of
a vessel.
[0005] While conventional stent technology is relatively well
developed, stent technologies related to treatment of the region of
a vessel bifurcation are still being developed. One challenge
related to treatment of a vessel bifurcation involves the
minimization of restenosis of the treated vessel.
SUMMARY
[0006] The present disclosure relates generally to catheter
assemblies for treatment of bifurcated lumens in a patient, such as
vessel bifurcations.
[0007] In one arrangement, a catheter assembly for deployment in a
vessel includes a catheter shaft extending from a proximal end
portion to a distal end portion. A balloon is operatively coupled
to the distal end portion of the catheter shaft. At least one
cutting member is coupled to the catheter assembly. As the balloon
is inflated, the cutting member is moved to a position to cut a
portion of the vessel.
[0008] There is no requirement that an arrangement or method
include all features characterized herein to obtain some advantage
according to this disclosure.
DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a schematic representation of an example catheter
assembly for treatment of a vessel bifurcation shown in a
non-deployed state.
[0010] FIG. 2 is a schematic perspective representation of a distal
portion of the catheter assembly of FIG. 1.
[0011] FIG. 3 is a schematic cross-sectional view of the distal
portion of the catheter assembly of FIG. 1 shown in a deployed
state.
[0012] FIG. 4 is a schematic side view of the catheter assembly
shown in FIG. 1 in a position prepared for treatment of a vessel
bifurcation.
[0013] FIG. 5 is a schematic side view of the catheter assembly
shown in FIG. 4 with the side catheter branch extending into a
branch vessel of the vessel bifurcation.
[0014] FIG. 6 is a schematic side view of the catheter assembly
shown in FIG. 5 with the side and main balloons inflated at the
vessel bifurcation.
[0015] FIG. 7 is a schematic representation of a distal portion of
another example catheter assembly for treatment of a vessel
bifurcation shown in a deployed state.
[0016] FIG. 8 is a schematic representation of a distal portion of
another example catheter assembly for treatment of a vessel
bifurcation shown in a deployed state.
[0017] FIG. 9 is a schematic end view of the balloon of the distal
portion of the catheter assembly of FIG. 8 in a non-deployed
state.
[0018] FIG. 10 is a schematic representation of a distal portion of
another example catheter assembly for treatment of a vessel
bifurcation shown in a deployed state.
[0019] FIG. 11 is a schematic view of an example cutting
member.
[0020] FIG. 12 is another schematic view of the cutting member of
FIG. 11.
[0021] FIG. 13 is another schematic view of the cutting member of
FIG. 11.
DETAILED DESCRIPTION
I. Overview
[0022] This disclosure relates to bifurcation treatment systems,
catheter assemblies, and related methods of treating bifurcations
in a patient's body. The term "bifurcation" means a division
location from one unit into two or more units. Generally, two types
of bifurcations of a body organ include: 1) a main tubular member
defining a main lumen and a branch tubular member defining a branch
lumen that extends or branches off from the main tubular member,
wherein the main and branch lumens are in fluid communication with
each other; and 2) a primary or main member defining a primary or
main lumen (also referred to as a parent lumen) that splits into
first and second branch members defining first and second branch
lumens. The term "lumen" means the cavity or bore of a tubular
structure such as a tubular organ (e.g., a blood vessel).
[0023] Example applications of the principles disclosed herein
include cardiac, coronary, renal, peripheral vascular,
gastrointestinal, pulmonary, urinary, and neurovascular systems.
Bifurcated vessels in such systems can become partially or fully
blocked over time, which is referred to as stenosis of the artery.
There are various procedures to treat the stenosis of a vessel,
including angioplasty and/or the placement of a stent at the point
of stenosis to reopen the vessel. Restenosis of the bifurcated
vessel can occur over time. It is desirable to minimize the effects
of restenosis.
[0024] The catheter assemblies, systems and methods disclosed
herein can be used for locating a branch vessel of the vessel
bifurcation and for treatment of stenoses of such vessels. In some
examples, the catheter assemblies include one or more cutting
members that are used to cut the vessel tissue at or near the
stenosis. As used herein, the term "cut" means to gash, incise,
slash, slit, open, or otherwise penetrate. In one example, the
cutting is done during delivery of a therapy, such as the placement
of a stent relative to the vessel bifurcation for treatment of the
vessel bifurcation. Other arrangements are possible. In the
examples shown, the cutting of the vessel tissue can help to
minimize restenosis of the vessel.
II. The Example Illustrated in FIGS. 1-6
[0025] An example catheter assembly 10 is shown schematically with
reference to FIGS. 1-6. The catheter assembly 10 is configured for
treatment of a vessel bifurcation, such as a vessel bifurcation 80
described below.
[0026] Referring now to FIG. 1, the catheter assembly 10 includes a
main catheter branch 12 and a side catheter branch 14. The main
catheter branch 12 includes a catheter shaft 20 having a proximal
end portion 28 with a proximal end 18 and a distal end portion 30.
The catheter shaft 20 defines a main inflation lumen extending
therethrough. The main catheter branch 12 further includes a main
guidewire housing 22. The main guidewire housing 22 defines a main
guidewire lumen.
[0027] The main catheter branch 12 further includes a main balloon
24 extending along the guidewire housing 22. A proximal waist 38 of
the main balloon 24 is operably mounted to the catheter shaft 20,
and a distal waist 36 of the main balloon 24 is operably mounted to
the main guidewire housing 22.
[0028] The main catheter branch 12 further includes a side balloon
26. See FIG. 3. The side balloon 26 includes an inflatable portion
45, a distal waist 44, and proximal waist 46. The side balloon 26
generally extends around the main balloon 24.
[0029] The waist members 44, 46 define a side inflation lumen
through which inflation fluid is provided to the side balloon 26.
When uninflated, the inflatable portion 45 of the side balloon 26
maintains a generally collapsed profile. When inflated as shown in
FIG. 3, the inflatable portion 45 of the side balloon 26 extends
radially outward relative to the longitudinal axis of the main
balloon 24.
[0030] Typically, the distal waist 44 is operably mounted to the
main guidewire member 22 distal of the main balloon 24, and the
distal waist 44 is also operably mounted in fluid communication
with the side balloon 26. The proximal waist 46 is operably mounted
in fluid communication to the inflation portion 45. The proximal
waist 44 is also operably mounted to the distal end portion of the
catheter shaft 20 in fluid communication with the main inflation
lumen therein. The main balloon 24 is also coupled in fluid
communication with the inflation lumen.
[0031] As shown in FIGS. 1 and 3, the side catheter branch 14
extends generally along the catheter shaft 20. In examples, the
side catheter branch 14 is generally parallel to the catheter shaft
20, although other configurations are possible. The side catheter
branch 14 has a side guidewire lumen extending therethrough. The
side catheter branch 14 is used to align features of the catheter
assembly 10 with the ostium into the branch vessel, as described
below.
[0032] In the example shown in FIGS. 1 and 3, the side catheter
branch 14 is coupled to the main catheter branch 12 by a ring
assembly 53. The ring assembly 53 including a first portion 55
coupled to the main catheter branch 12 so that the ring assembly 53
is fixed axially with respect to the main catheter branch 12. In
the example shown, the ring assembly 53 is positioned proximally on
the main catheter branch 12 approximately one inch from the
proximal waist 38 of the main balloon 24. Other positions are
possible. A second portion 57 of the ring assembly 53 is coupled to
the first component 55 such that the second portion 57 can rotate
about the first component 55. The side catheter branch 14 is
coupled to the second portion 57 so that the side catheter branch
14 can rotate about the main catheter branch 12, while being fixed
axially by the ring assembly 53.
[0033] Referring to FIGS. 1-3, positioned about the main and side
balloons 24, 26 is a sheath 52. In example arrangements, the sheath
52 is crimped or otherwise attached to the balloons 24, 26 and/or
the side catheter branch 14. For example, in one arrangement, the
sheath 52 is coupled to the side catheter branch 14 so that the
sheath 52 can rotate about the main catheter branch 12 to a desired
orientation.
[0034] Attached to an outer circumference 54 of the sheath 52 are
one or more articulated cutting members, such as cutting members
62, 64. Each cutting member 62, 64 includes a first cutting portion
66 and a second cutting portion 68. In the example shown, the first
cutting portions 66 of each of the cutting members 62, 64 are
coupled to the outer circumference 54 of the sheath 52.
[0035] The second cutting portions 68 are rotatably coupled to the
first cutting portions 66 so that the second cutting portions 68
can pivot with respect to the first cutting portions 66. In example
arrangements, the second cutting portions 68 can pivot generally
outwardly away from the outer circumference 54 of the sheath 52.
For example, the second cutting portions 68 can rotate generally
radially outwardly from the outer circumference 54. In some
arrangements, the second cutting portions 68 rotate in a direction
generally perpendicular to a longitudinal axis of the main catheter
branch 12. In one arrangement, the second cutting portions 68 are
positioned to extend adjacent to and overlap an aperture 92 formed
in the sheath 54 (see FIG. 2), such that the side balloon 26 can
extend through the aperture 92 to contact and pivot the second
cutting portions 68.
[0036] For example, referring now to FIG. 3, the catheter assembly
10 is shown with the main and side balloons 24, 26 in expanded form
in the deployed state. As the side balloon 26 is expanded, the
inflatable portion 45 extends through the aperture 92 in the sheath
52 (see FIG. 2) to engage a lower surface 98 of the second cutting
portions 68 of the cutting members 62, 64. As the inflatable
portion 45 expands, the inflatable portion 45 forces the second
cutting portions 68 to pivot in opposite directions 94, 96 with
respect to the first cutting portions 66. In this manner, the first
and second cutting portions 66, 68 can be forced against and cut
the stenosis in the main and branch portions of the vessel, as
described further below.
[0037] An outer surface 70 of each cutting member 62, 64 is
configured to cut tissue, such as a stenosis in the bifurcated
vessel. For example, in one embodiment, the outer surface 70
includes a sharpened edge that can be used to mechanically cut the
stenosis. In other arrangements, the outer surface 70 can be used
to deliver other therapies that are capable of cutting the
stenosis, such as Radio Frequency (RF), ultrasonic, or other
electromechanical ablation therapies.
[0038] The cutting members 62, 64 can be delivered to the stenosis
in the bifurcated vessel using a variety of methods. For example,
as described below with reference to FIGS. 4-6, the outer surface
70 of the cutting members 62, 64 can be coated with a material,
such as polymeric material, that covers the cutting members 62, 64
so that the cutting members 62, 64 do not cut the blood vessel
during delivery of the cutting member 62, 64 to the stenosis. Once
at the desired site, the polymeric material can be removed so that
the outer surface 70 can be used to cut the stenosis. For example,
in one arrangement, the coating is removed by applying an
electrical charge to the cutting members 62, 64 to erode the
polymeric material. In other embodiments, the cutting members 62,
64 are configured such that, as the cutting members 62, 64 are
employed as described below, the outer surface 70 cuts through the
coating to cut the blood vessel.
[0039] In yet other arrangements, the cutting members 62, 64 can be
folded against the outer circumference 54 of the sheath 52 during
delivery. When the cutting members 62, 64 reach the stenosis, the
cutting members 62, 64 can be mechanically moved into the cutting
position. In one example, the cutting members 62, 64 are moved into
the cutting position using hydraulic pressure from the fluid in the
inflation lumens for the main and side balloons 24, 26. In another
embodiment, electricity is used to excite a ferrofluidic fluid
within the balloons 24, 26 and/or a lumen connected to the cutting
members 62, 64 to cause the cutting members 62, 64 to move from a
stowed position to the cutting position, or the cutting members 62,
64 can themselves include Electroactive Polymers (EAP). In another
arrangement, the cutting members 62, 64 can be made of a shape
member material such as nitinol. In yet another example, an outer
sheath can be placed over the cutting members 62, 64 during
delivery. The outer sheath can be removed once the cutting members
62, 64 are at the stenosis to allow the cutting members 62, 64 to
cut the stenosis.
[0040] In yet another example, the cutting members 62, 64 can be
coupled directly to the main or side balloons. See FIGS. 7 and 8.
In such arrangements, the cutting members can be encompassed within
the folds of the main or side balloons during delivery. See FIG. 9.
Upon expansion of the main or side balloons, the cutting members
62, 64 are exposed to allow the cutting members 62, 64 to cut the
walls of the vessels. Other examples are possible.
[0041] In yet other examples, a plurality of cutting members can be
mounted about the circumference of the sheath 52. Upon delivery the
sheath 52 extends at least partially into the bifurcated vessel, so
that the cutting members located on the sheath can cut the
bifurcated vessel. The cutting members on the sheath can also
contact portions of the main vessel to cut any stenosis located in
the main vessel as well. Other configurations are possible.
[0042] Referring now to FIGS. 4-6, the catheter assembly 10 can be
used for treatment of the vessel bifurcation 80. Typically, a main
vessel guidewire 62 is inserted into a main vessel 82 of the vessel
bifurcation 80 to a point distal of the vessel bifurcation. A
branch vessel guidewire 60 is advanced to the vessel bifurcation
and inserted through an ostium or opening 86 of a branch vessel 84.
A proximal end of the main vessel guidewire 62 is then inserted
into the main guidewire lumen, and a proximal end of the branch
vessel guidewire 60 is inserted into a branch guidewire lumen
defined by the side catheter branch 14. See FIG. 4.
[0043] The catheter assembly 10 is advanced over the guidewires 60,
62 to the vessel bifurcation 80. See FIG. 5. The catheter assembly
10 is then advanced further distally until a distal end portion 56
of the side catheter branch 14 is positioned within the branch
vessel 60. A marker system (described further below) can be used to
help confirm proper radial and axial alignment of the lateral
branch opening 54 of the sheath 52 relative to the ostium 86 into
the branch vessel 84.
[0044] As the side catheter branch 14 follows the branch vessel
guidewire 60, the side catheter branch 14 rotates about the main
catheter branch 12 at the ring assembly 53. As the side catheter
branch 14 rotates about the main catheter branch 12, the sheath 52,
which is coupled to the side catheter branch 14, also rotates about
the main catheter branch 12 so that the aperture 92 formed in the
sheath 54 (see FIG. 2), is aligned with the ostium 86 of the branch
vessel 84.
[0045] After proper positioning of the catheter assembly 10 is
confirmed, the main and branch balloons 24, 26 are inflated. As the
side balloon 26 is inflated, the inflatable portion 45 positioned
at the aperture 92 extends through the aperture of the sheath 54.
The remaining portions of the side balloon 26 contact and are held
within the sheath 52 so that only the inflatable portion 45 extends
through the aperture 92. The inflatable portion 45 contacts and
moves the second cutting portions 68 of the cutting members 62, 64.
As the inflatable portion 45 is further inflated, the second
cutting portions 68 pivot in the directions 94, 96 with respect to
the first cutting portions 66 so that the second cutting portions
68 engage the ostium 86 and/or the wall of the branch vessel 84. In
this position, the first and second cutting portions 66, 68 of the
cutting members 62, 64 can be used to cut any stenosis on the walls
of the main or branch vessels 82, 84.
[0046] In one example, the sheath 52 can be moved axially within
the main vessel 82 when the cutting members 62, 64 are in place to
cause the cutting members 62, 64 to cut the stenosis in the vessels
82, 84 as desired. For example, in one arrangement, the second
portion 57 of the ring assembly 53 can be released from the first
component 55 once the catheter assembly 10 is in place so that the
side catheter branch 14 can be moved axially with respect to the
main catheter branch 12 to move the sheath 52 axially within the
main vessel 82. In other arrangements, other therapies such as RF
or electrical can be delivered to initiate cutting.
[0047] In some examples, additional therapy can be delivered after
the cutting members 62, 64 are used to cut the stenosis. For
example, in one arrangement, one or more drugs are delivered to
further minimize restenosis after the walls of the vessels 82, 84
have been cut.
[0048] In another example, a bifurcated stent is delivered to the
bifurcation 80 after the walls of the vessels 82, 84 are cut. For
example, a stent (not shown) can be positioned about the sheath 54.
After the cutting members 62, 64 are used to cut the stenosis, the
sheath 54 can be removed from the catheter assembly 10, and the
stent can then be delivered to the bifurcated vessel by further
expansion of the main and side balloons 24, 26.
[0049] Other configurations are possible. For instance, in another
example, the cutting members can be coupled directly to the stent.
The cutting members can be made of a bioabsorbable material, such
as iron or magnesium, so that, after delivery and cutting, the
cutting members dissolve or otherwise dissipate over time.
[0050] It can be advantageous to use the cutting members 62, 64 to
cut and create stress points on the walls of the main and/or side
vessels 82, 84 adjacent to the ostium 86 because cutting of the
area of the stenosis can minimize future restenosis of the area.
For example, typically, the healthy portions of the blood vessel
are more elastic than the heavily calcified regions of the
stenosis. During deployment of therapy using balloons, the health
portions of the blood vessel are therefore stretched more easily,
which can cause stress-induced inflammatory effects leading to new
stenoses. The use of the cutting members to cut the calcification
associated with the stenoses allows the stenosis to be more easily
expanded as well, thereby causing less stretching of the healthy
blood vessel walls and the associated stress-induced inflammatory
effects.
III. The Example Illustrated in FIG. 7
[0051] Referring now to FIG. 7, another example distal end portion
110 of a catheter assembly is shown. The distal end portion 110 is
similar to that of the catheter assembly 10 described above, except
that cutting members 162, 164 are coupled to the side balloon 26,
rather than a sheath. The first cutting portion 66 of each cutting
member 162, 164 is coupled to the balloon 26, and the second
cutting portion 68 of each cutting member 162, 164 is coupled to
the first cutting portion 66 so that the second cutting portion 68
can pivot with respect to the first cutting portion 66.
[0052] As the side balloon 26 is inflated as shown in FIG. 7, the
inflatable portion 45 of the side balloon 26 contacts and moves the
second cutting portion 68 of each of the cutting members 162, 164
so that the second cutting portions 68 pivot in directions 194,
196. In this manner, the first cutting portions 66 can be used to
cut the wall of the main vessel, and the second cutting portions 68
can be used to cut the wall of the branch vessel of the
bifurcation.
IV. The Example Illustrated in FIGS. 8 and 9
[0053] Referring now to FIG. 8, another example distal end portion
210 of a catheter assembly is shown. The distal end portion 210
includes a balloon 224 with a bulge 226 when inflated as shown in
FIG. 8. Cutting members 262, 264 are coupled to the balloon 224.
The first cutting portion 66 of each cutting member 262, 264 is
coupled to the balloon 224, and the second cutting portion 68 of
each cutting member 262, 264 is coupled to the first cutting
portion 66 so that the second cutting portion 68 can pivot with
respect to the first cutting portion 66.
[0054] As the balloon 224 is inflated as shown in FIG. 8, the bulge
226 contacts and moves the second cutting portion 68 of each of the
cutting members 262, 264 so that the second cutting portions 68
pivots. In this manner, the first cutting portions 266 can be used
to cut the wall of the main vessel, and the second cutting portions
268 can be used to cut the wall of the branch vessel at the
bifurcation.
[0055] Referring now to FIG. 9, the balloon 224 is shown in a
semi-folded state. A plurality of folds 228 are formed as the
balloon 224 is folded to reduce the profile of the balloon 224 in
the non-deployed state. An example of a balloon folded in such a
manner is shown in U.S. Pat. No. 7,160,317 filed on Jan. 4, 2002,
the entirety of which is hereby incorporated by reference. The
cutting members 262 and 264 (not shown in this view) are positioned
in the interior between two folds 228 of the balloon 224 so that
the cutting members 262, 264 are shielded by the folds 228 of the
balloon 224 until the balloon 224 is expanded. Upon expansion of
the balloon 224, the folds 228 dissipate and the cutting members
262, 264 are exposed and moved to the cutting position shown in
FIG. 8.
V. Alternative Arrangements for the Cutting Members
[0056] Referring now to FIG. 10, another arrangement for a distal
end portion 310 of a catheter assembly is shown. The distal end
portion 310 includes a plurality of cutting members 362, 363, 364,
365 coupled to the balloon 224. In the example shown, the cutting
members 362, 364 are coupled to the balloon 224, and the cutting
members 363, 365 are coupled to the bulge 226. The cutting members
362, 363, 364, 365 each form a "sharks tooth" or pyramid
configuration with a pointed cutting surface 370. In this manner,
the cutting members 362, 364 can be used to cut the wall of the
main vessel, and the cutting member 363, 365 can be used to cut the
wall of the branch vessel of the bifurcation. In the example shown,
the cutting members 363, 364, 365, 366 are configured to fold
laterally against the surface of the balloon 224 until the balloon
224 is inflated. For example, elastic members (not shown) made of a
compliant material such as silicon rubber can be used to hold the
cutting members 363, 364, 365, 366 against the surface of the
balloon 224 prior to deployment.
[0057] Referring now to FIGS. 11-13, another example cutting member
462 is shown, which is similar to the cutting members 62, 64 shown
in FIGS. 1-9. The cutting member 462 includes first and second
cutting portions 466, 468. The second cutting portion 468 pivots
about a point 472 in a direction 480 with respect to the first
cutting portion 466. In example embodiments, the cutting member 462
is configured to allow the second cutting portion 468 to pivot to a
specified angle .alpha. with respect to the first cutting portion
466. In some examples, the angle .alpha. is greater than 90
degrees. In other examples, the angle .alpha. is less than 90
degrees. In the examples in which the angle .alpha. is less than 90
degrees, the first and second cutting portions 466, 468 can create
a "scissor-type" action that captures and cuts the vessel at the
ostium between the first and second cutting portions 466, 468 to
thereby enhance the cutting action of the cutting member 462. In
example arrangements, the appropriate angle .alpha. is determined
by the caregiver during a prescan of the bifurcation.
[0058] Other arrangements for the cutting members are possible. For
example, in one alternative, each cutting member is broken into
more than two portions that can pivot with respect to one another.
In yet another example, each cutting member is made of a single
portion. In yet another arrangement, some of the cutting members
can be located on a sheath, and other cutting members can be
located on the main or side balloons. Other configurations are
possible.
[0059] The cutting members can be deployed at various points along
the sheath and/or balloon to cut various portions of the walls of
the main or branch vessels. In one alternative example, a plurality
of cutting members are formed along the main balloon, side balloon,
sheath, and/or an outer circumference of the side branch lumen to
cut the walls of the main and/or side branch vessels at a plurality
of sites. The cutting members can extend at one or a plurality of
directions and/or orientations with respect to the other cutting
members and the walls of the main and/or side branch vessels.
[0060] In yet another alternative, a kissing balloon arrangement
can be used, in which a main balloon is positioned in the main
vessel, and a side balloon is positioned along the main balloon. A
distal part of the side balloon is positioned through the ostium
into a branch vessel. Cutting members can be positioned along the
side balloon, such as on the distal part that extends into the
branch vessel. Upon inflation of the side balloon, the cutting
members cut the vessel wall of the branch vessel, as described
above. Other configurations are possible.
VI. Other Alternative Materials and Arrangements
[0061] In some arrangements, the distal end portions 30, 110, 210,
310 of the catheter assemblies can include marker material that is
visible under X-ray or in fluoroscopy procedures. In some examples,
the mark material is positioned along the distal end portions of
the main and side catheter branches. Features of the system 10 that
include marker material can be more easily identified and
distinguished under X-ray or in fluoroscopy procedures. Some
example marker materials include gold, platinum and tungsten. In
one embodiment, the marker material can be included in a band
structure that is secured to at least one of the main and side
catheter branches 12, 14. In other embodiments, the marker material
is part of the material composition of portions of the main and
side catheter branches 12, 14. Viewability of features of the
catheter assembly 10 under X-ray or fluoroscopy can assist the
physician operating the system 10 to more easily adjust a position
of the system 10 relative to the vessel bifurcation 80. Example
markers and marker materials suitable for use with system 10 are
described in U.S. Pat. No. 6,692,483 to Vardi, et al., and
co-pending U.S. Provisional Patent Application Ser. No. 60/776,149,
filed on Feb. 22, 2006, and titled MARKER ARRANGEMENT
[0062] FOR BIFURCATION CATHETER, which patent matters are
incorporated herein by reference.
[0063] Alternative catheter assemblies to those described above are
configured for use with stents having self-expanding features.
Self-expanding stents and self-expanding features of a stent
typically do not require the use of an inflatable member such as a
balloon to expand the stent or stent feature. Typically,
self-expanding stents, such as those stents described in U.S.
Published Patent Application No. 2004/0176837, are held in a
constricted state using a sheath that fits over the stent. In the
constricted state, the stent is able to navigate through a body
lumen to the treatment site. Once the stent and sheath are
positioned at the treatment site, the sheath is retracted
proximally to release the stent for expansion of the stent into a
radially expanded state.
[0064] A wide variety of stents, catheters, and guidewire
configurations can be used with the catheter assembly embodiments
of the present disclosure. The inventive principles disclosed
herein should not be limited to any particular design or
configuration. Some example stents that can be used with the
catheter assemblies disclosed herein can be found in, for example,
U.S. Pat. Nos. 6,210,429, 6,325,826 and 6,706,062 to Vardi et al.,
U.S. Pat. No. 7,220,275 to Davidson et al., and U.S. Published
Patent Application No. 2004/0176837 titled SELF-EXPANDING STENT AND
CATHETER ASSEMBLY AND METHOD FOR TREATING BIFURCATIONS, the entire
contents of which are incorporated herein by reference. In general,
the aforementioned stents include a lateral branch opening located
between distal and proximal open ends of the stent. The lateral
branch opening defines a path between an inner lumen of the stent
and an area outside of the stent. The stent lateral branch opening
is distinct from the cell openings defined between strut structures
from which the stent sidewall is constructed. In some stents, the
lateral branch opening can be surrounded by expandable structure.
The expandable structure can be configured to extend radially into
the branch lumen of the bifurcation upon expansion of, for example,
an inflatable portion of the bifurcation treatment system.
Typically, the stent is expanded after being positioned in the main
lumen with the lateral branch opening aligned with an opening into
the branch lumen. Alignment of the lateral branch opening with the
opening into the branch lumen includes both radial and axial
alignment. The stent, including the expandable structure
surrounding the lateral branch opening, can be expanded with a
single expansion or multiple expansions using one or more
inflatable members.
[0065] The main and side balloons, and all other balloons disclosed
herein, can be made of any suitable balloon material including
compliant and non-compliant materials and combinations thereof.
Some example materials for the balloons and catheters disclosed
herein include thermoplastic polymers, polyethylene (high density,
low density, intermediate density, linear low density), various
co-polymers and blends of polyethylene, ionomers, polyesters,
polycarbonates, polyamides, poly-vinyl chloride,
acrylonitrile-butadiene-styrene copolymers, polyether-polyester
copolymers, and polyetherpolyamide copolymers. One suitable
material is SURLYN.RTM., a copolymer polyolefin material (DuPont de
Nemours, Wilmington, Del.). Still further suitable materials
include thermoplastic polymers and thermoset polymeric materials,
poly(ethylene terephthalate) (commonly referred to as PET),
thermoplastic polyamide, polyphenylene sulfides, polypropylene.
Some other example materials include polyurethanes and block
copolymers, such as polyamide-polyether block copolymers or
amide-tetramethylene glycol copolymers. Additional examples include
the PEBAX.RTM. (a polyamide/polyether/polyester block copolymer)
family of polymers, e.g., PEBAX.RTM. 70D, 72D, 2533, 5533, 6333,
7033, or 7233 (available from Elf AtoChem, Philadelphia, Pa.).
Other examples include nylons, such as aliphatic nylons, for
example, Vestamid L21011F, Nylon 11 (Elf Atochem), Nylon 6 (Allied
Signal), Nylon 6/10 (BASF), Nylon 6/12 (Ashley Polymers), or Nylon
12. Additional examples of nylons include aromatic nylons, such as
Grivory (EMS) and Nylon MXD-6. Other nylons and/or combinations of
nylons can also be used. Still further examples include
polybutylene terephthalate (PBT), such as CELANEX.RTM. (available
from Ticona, Summit, N.J.), polyester/ether block copolymers such
as ARNITEL.RTM. (available from DSM, Erionspilla, Ind.), e.g.,
ARNITEL.RTM. EM740, aromatic amides such as Trogamid (PA6-3-T,
Degussa), and thermoplastic elastomers such as HYTREL.RTM. (Dupont
de Nemours, Wilmington, Del.). In some embodiments, the PEBAX.RTM.,
HYTREL.RTM., and ARNITEL.RTM. materials have a Shore D hardness of
about 45D to about 82D. The balloon materials can be used pure or
as blends. For example, a blend may include a PBT and one or more
PBT thermoplastic elastomers, such as RITEFLEX.RTM. (available from
Ticona), ARNITEL.RTM., or HYTREL.RTM., or polyethylene
terephthalate (PET) and a thermoplastic elastomer, such as a PBT
thermoplastic elastomer. Additional examples of balloon material
can be found in U.S. Pat. No. 6,146,356, which is incorporated
herein by reference.
VII. Conclusion
[0066] As described herein, example arrangements include a catheter
assembly for deployment in a bifurcated vessel. The catheter
assembly includes a catheter shaft extending from a proximal end
portion to a distal end portion, and a balloon operatively coupled
to the distal end portion of the catheter shaft. The catheter
assembly also includes a sheath positioned about the balloon, the
sheath including at least one cutting member coupled thereto. As
the balloon is inflated, the cutting member is moved to a position
to cut a portion of a main vessel and/or the bifurcated vessel. In
some examples, the cutting member includes first and second
portions, the first portion being coupled to and pivoting with
respect to the second portion to cut the bifurcated vessel. In this
manner, restenosis of the bifurcated vessel is minimized.
[0067] It is noted that not all of the features characterized
herein need to be incorporated within a given arrangement, for the
arrangement to include improvements according to the present
disclosure.
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