U.S. patent application number 11/273186 was filed with the patent office on 2007-05-17 for stent with spiral side-branch support designs.
This patent application is currently assigned to Boston Scientific Scimed, Inc.. Invention is credited to Todd Bethel, Thomas E. Broome, Tracee Eidenschink, Daniel Gregorich, Matt Heidner, Michael P. Meyer, Amnon Yadin.
Application Number | 20070112418 11/273186 |
Document ID | / |
Family ID | 37649501 |
Filed Date | 2007-05-17 |
United States Patent
Application |
20070112418 |
Kind Code |
A1 |
Eidenschink; Tracee ; et
al. |
May 17, 2007 |
Stent with spiral side-branch support designs
Abstract
An expandable stent may be made having an expandable spiral side
branch support section having a spiral configuration and disposed
about a center point. The expandable spiral side branch support
section is configured to expand outward to allow for the formation
of a bifurcated stent with a side branch.
Inventors: |
Eidenschink; Tracee;
(Wayzata, MN) ; Meyer; Michael P.; (Richfield,
MN) ; Heidner; Matt; (Maple Grove, MN) ;
Gregorich; Daniel; (St. Louis Park, MN) ; Yadin;
Amnon; (Pleasanton, MN) ; Broome; Thomas E.;
(Shakopee, MN) ; Bethel; Todd; (Lakeville,
MN) |
Correspondence
Address: |
VIDAS, ARRETT & STEINKRAUS, P.A.
6109 BLUE CIRCLE DRIVE
SUITE 2000
MINNETONKA
MN
55343-9185
US
|
Assignee: |
Boston Scientific Scimed,
Inc.
Maple Grove
MN
|
Family ID: |
37649501 |
Appl. No.: |
11/273186 |
Filed: |
November 14, 2005 |
Current U.S.
Class: |
623/1.35 |
Current CPC
Class: |
A61F 2002/91525
20130101; A61F 2220/005 20130101; A61F 2230/0091 20130101; A61F
2/856 20130101; A61F 2230/005 20130101; A61F 2002/91533 20130101;
A61F 2002/91558 20130101; A61F 2220/0058 20130101; A61F 2/91
20130101; A61F 2002/91575 20130101; A61F 2/915 20130101 |
Class at
Publication: |
623/001.35 |
International
Class: |
A61F 2/06 20060101
A61F002/06 |
Claims
1. An expandable stent having an exterior surface and an interior
surface, an inner diameter and an outer diameter, the inner
diameter being constant, there being a longitudinal flowpath
through the stent, the stent comprising an expandable spiral side
branch support section having a spiral configuration and disposed
about a center point, the center point located at a first
longitudinal coordinate and circumferential coordinate, the spiral
side branch support section comprising at least one spiral arm
forming a curve extending at least partially around the center
point, the at least one spiral arm having a first end and a second
end, the second end positioned closer to the center point than the
first end, the stent having no more than one spiral branch support
section disposed about a center point located at the first
longitudinal coordinate.
2. The stent of claim 1, wherein the distal end of the at least one
spiral arm is a free end.
3. The stent of claim 1 having only one expandable spiral side
branch support section.
4. The stent of claim 3 wherein the one expandable spiral side
branch support section comprises only one spiral arm.
5. The stent of claim 3 wherein the one expandable spiral side
branch support section comprises a plurality of spiral arms.
6. The stent of claim 5, wherein each of the spiral arms is
attached at one end to a member which forms a circumferential
member extending along the exterior surface of the stent, the
circumferential member extending only part of the way about the
longitudinal axis of the stent.
7. The stent of claim 6 wherein the circumferential member includes
at least one apex and one valley.
8. The stent of claim 7 wherein the circumferential member has a
serpentine shape, the serpentine shape having turns.
9. The stent of claim 6, wherein the circumferential member has a
locking mechanism.
10. The stent of claim 1 having a plurality of expandable spiral
side branch sections.
11. The stent of claim 10 wherein each of at least two of the
expandable spiral side branch sections comprise a plurality of
spiral arms.
12. The stent of claim 1 having at least one expandable spiral side
branch section which comprises a plurality of spiral arms, each of
the spiral arms attached at one end to a first member which forms a
first closed pathway about the center point and at another end to a
second member which forms a second closed pathway about the center
point, the first closed pathway being longer than the second closed
pathway.
13. An expandable stent having an exterior surface and an interior
surface, an inner diameter and an outer diameter, there being a
longitudinal flowpath through the stent, the stent comprising an
expandable spiral side branch support section which lies flush with
the inner surface of the remainder of the stent, the expandable
spiral side branch having a spiral configuration and disposed about
a center point, the center point located at a first longitudinal
coordinate and circumferential coordinate, the spiral side branch
support section comprising at least one spiral arm forming a curve
extending at least partially around the center point, the at least
one spiral arm having a first end and a second end, the second end
positioned closer to the center point than the first end, the stent
having no more than one spiral branch support section disposed
about a center point located at the first longitudinal
coordinate.
14. The stent of claim 13 having only one expandable spiral side
branch support section.
15. The stent of claim 13 wherein the one expandable spiral side
branch support section comprises only one spiral arm.
16. The stent of claim 13 wherein the one expandable spiral side
branch support section comprises a plurality of spiral arms.
17. A bifurcated stent formed by: providing the expandable stent of
claim 1; expanding the stent to a first diameter expanding the at
least one spiral arm outward to define a second flowpath which
branches off the longitudinal flowpath.
18. The stent of claim 17 wherein at least one of the expanding
steps is accomplished with a balloon.
19. The stent of claim 17 wherein at least one of the expanding
steps is accomplished by withdrawing a sheath which is disposed
over at least a portion of the stent.
20. In combination, a catheter and an expandable stent having a
tubular surface disposed about a longitudinal flowpath, the tubular
surface including at least one arm which is arranged along the
surface about an opening, the opening having a first size in an
unexpanded state of the stent, the at least one arm arranged to
define a spiral, the expandable stent disposed about the catheter,
the catheter including an elongated member which extends through
the opening.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
[0002] Not Applicable
BACKGROUND OF THE INVENTION
[0003] Stents, grafts, stent-grafts, vena cava filters and similar
implantable medical devices, collectively referred to hereinafter
as stents, are radially expandable endoprostheses which are
typically intravascular implants capable of being implanted
transluminally and enlarged radially after being introduced
percutaneously. Stents may be implanted in a variety of body lumens
or vessels such as within the vascular system, urinary tracts, bile
ducts, etc. Stents may be used to reinforce body vessels and to
prevent restenosis following angioplasty in the vascular system.
They may be self-expanding or expanded by an internal radial force,
such as when mounted on a balloon.
[0004] Stents are generally tubular devices for insertion into body
lumens. Balloon expandable stents require mounting over a balloon,
positioning, and inflation of the balloon to expand the stent
radially outward. Self-expanding stents expand into place when
unconstrained, without requiring assistance from a balloon. A
self-expanding stent is biased so as to expand upon release from
the delivery catheter. Some stents may be characterized as hybrid
stents which have some characteristics of both self-expandable and
balloon expandable stents.
[0005] Stents may be constructed from a variety of materials such
as stainless steel, Elgiloy, nitinol, shape memory polymers, etc.
Stents may also be formed in a variety of manners as well. For
example, a stent may be formed by etching or cutting the stent
pattern from a tube or section of stent material; a sheet of stent
material may be cut or etched according to a desired stent pattern
whereupon the sheet may be rolled or other wise formed into the
desired tubular or bifurcated tubular shape of the stent; one or
more wires or ribbons of stent material may be braided or otherwise
formed into a desired shape and pattern.
[0006] Within the vasculature however, it is not uncommon for
stenoses to form at a vessel bifurcation. A bifurcation is an area
of the vasculature or other portion of the body where a first (or
parent) vessel is bifurcated into two or more branch vessels. Where
a stenotic lesion or lesions form at such a bifurcations, the
lesion(s) can affect only one of the vessels (i.e., either of the
branch vessels or the parent vessel) two of the vessels, or all
three vessels. Many prior art stents however are not wholly
satisfactory for use where the site of desired application of the
stent is juxtaposed or extends across a bifurcation in an artery or
vein such, for example, as the bifurcation in the mammalian aortic
artery into the common iliac arteries.
[0007] All U.S. patents and applications and all other published
documents mentioned anywhere in this application are incorporated
herein by reference in their entirety
[0008] Without limiting the scope of the invention a brief summary
of some of the claimed embodiments of the invention is set forth
below. Additional details of the summarized embodiments of the
invention and/or additional embodiments of the invention may be
found in the Detailed Description of the Invention below.
[0009] A brief abstract of the technical disclosure in the
specification is provided as well only for the purposes of
complying with 37 C.F.R. 1.72. The abstract is not intended to be
used for interpreting the scope of the claims.
BRIEF SUMMARY OF THE INVENTION
[0010] The present invention includes many different embodiments.
Various embodiments of the invention are directed to designs of
stents, bifurcated stents and/or the methods utilized to deliver a
bifurcated stent to a bifurcation site.
[0011] In one or more embodiments, the invention is directed to an
expandable stent having a flow path therethrough and an exterior
surface and an interior surface, a constant inner diameter and an
outer diameter. The stent comprises an expandable spiral side
branch support section having a spiral configuration and disposed
about a center point. The center point is located at a first
longitudinal coordinate and circumferential coordinate. The spiral
side branch support section comprises at least one spiral arm
forming a curve extending at least partially around the center
point. The at least one spiral arm has a first end and a second
end, the second end positioned closer to the center point than the
first end. The stent has no more than one spiral branch support
section disposed about a center point located at the first
longitudinal coordinate.
[0012] In one or more embodiments, the invention is directed to an
expandable stent having a longitudinal flowpath therethrough and
having an exterior surface and an interior surface, an inner
diameter and an outer diameter. The stent comprises an expandable
spiral side branch support section which lies flush with the inner
surface of the remainder of the stent. The expandable spiral side
branch has a spiral configuration and is disposed about a center
point located at a first longitudinal coordinate and
circumferential coordinate. The spiral side branch support section
comprises at least one spiral arm forming a curve extending at
least partially around the center point. The at least one spiral
arm has a first end and a second end, the second end positioned
closer to the center point than the first end. The stent has no
more than one spiral branch support section disposed about a center
point located at the first longitudinal coordinate.
[0013] The invention is also directed to bifurcated stents formed
by providing any of the expandable stents disclosed herein,
expanding the stent to a first diameter and expanding the at least
one spiral arm outward to define a second flowpath which branches
off the longitudinal flowpath.
[0014] The invention is also directed to, in combination, a
catheter and an expandable stent having a tubular surface disposed
about a longitudinal flowpath, the tubular surface including at
least one arm which is arranged along the surface about an opening,
the opening having a first size in an unexpanded state of the
stent, the at least one arm arranged to define a spiral, the
expandable stent disposed about the catheter, the catheter
including an elongated member which extends through the expandable
spiral side branch support section.
[0015] Additional details and/or embodiments of the invention are
discussed below.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0016] A detailed description of the invention is hereafter
described with specific reference being made to the drawings.
[0017] FIG. 1 is a side view of the stent with a spiral side branch
section that has one spiral arm in the unexpanded state.
[0018] FIG. 2 is a view of the stent with a spiral side branch
section that has a plurality of spiral arms in the expanded
state.
[0019] FIG. 3 is a side view of the stent with a spiral side branch
section that has a circumferential member engaged to a plurality of
spiral arms in the unexpanded state.
[0020] FIG. 4 is a side view of the stent with another embodiment
of the spiral side branch section of FIG. 3 in the unexpanded
state.
[0021] FIG. 5 is a side view of the stent with a spiral side branch
section that has a plurality of spiral arms with free ends in the
unexpanded state.
[0022] FIG. 6 is a side view of the stent with a spiral side branch
section that has a plurality of spiral arms and a circumferential
member with a serpentine shape in the unexpanded state.
[0023] FIG. 7 is a side view of the stent with a spiral side branch
section that has a plurality of serpentine shaped circumferential
members and a plurality of spiral arms in an unexpanded state.
[0024] FIG. 8a is a side view of the stent with a spiral side
branch section that has a circumferential member with a locking
mechanism and a plurality of spiral arms in an unexpanded
state.
[0025] FIG. 8b shows a locking mechanism which may be used in the
stent of FIG. 8a.
[0026] FIG. 8c shows the locking mechanism of FIG. 8b immediately
prior to engagement
[0027] FIG. 9 is a side view of the stent in FIG. 8a with a
radiopaque marker on the circumferential member.
[0028] FIG. 10a is a side view of the stent of FIG. 8a with the
spiral side branch section in an expanded state, the spiral arms
are straight when in an expanded state.
[0029] FIG. 10b is a side view of the stent of FIG. 8a with the
spiral branch section in an expanded state, the spiral arms are
curved when in an expanded state.
[0030] FIG. 11 is a side view of the stent with a spiral side
branch section in an unexpanded state consisting of four spiral
arms.
[0031] FIG. 12 is a side view of the stent with a spiral side
branch section that has four spiral arms, each spiral arm having an
opening in the width of the spiral arm, in an unexpanded state.
[0032] FIG. 13 is a side view of the stent with the spiral side
branch section of FIG. 11 in an expanded state.
[0033] FIG. 14 is a side view of an embodiment of the stent with a
spiral side branch section that has a plurality of serpentine
shaped circumferential members and a plurality of spiral arms in an
unexpanded state.
[0034] FIG. 15 is a perspective view of the embodiment in FIG. 14
in an expanded state.
[0035] FIG. 16 is a side view of an embodiment of the stent with a
spiral side branch section that has a plurality of interconnected
spiral arms in an unexpanded state.
[0036] FIG. 17 is a perspective view of the embodiment in FIG. 16
in an expanded state.
DETAILED DESCRIPTION OF THE INVENTION
[0037] While this invention may be embodied in many different
forms, there are described in detail herein specific embodiments of
the invention. This description is an exemplification of the
principles of the invention and is not intended to limit the
invention to the particular embodiments illustrated.
[0038] For purposes of this disclosure, like reference numerals in
the figures shall refer to like features unless otherwise
indicated.
[0039] As used herein the term `stent` refers to an expandable
prosthesis for implantation into a body lumen or vessel and
includes devices such as stents, grafts, stent-grafts, vena cava
filters, expandable frameworks, etc.
[0040] Referring now to the drawings which are for the purposes of
illustrating embodiments of the invention only and not for purposes
of limiting same, in at least one embodiment of the invention, an
example of which is shown in FIG. 1, stent 20, shown in side view,
comprises an expandable spiral side branch support section 24.
Expandable spiral side branch support section 24 has a spiral
configuration and is disposed about a center opening 32 and center
point. The center point is located at a first longitudinal
coordinate and a first circumferential coordinate. The longitudinal
coordinate indicates where, along the length of the stent, the
center point is located. The circumferential coordinate indicates
where, about the circumference of the stent, the center point lies.
The spiral side branch support section 24 comprises at least one
spiral arm 28 forming a curve extending at least partially around
the center point. The at least one spiral arm has a first end and a
second end. One of the two ends is positioned closer to the center
point than the other of the two ends.
[0041] The stent of FIG. 1 has no more than one spiral branch
support section 24 located at the first longitudinal coordinate.
Thus, there are no other spiral branch support sections which are
disposed about the circumference of the stent and located at the
first longitudinal coordinate. In other embodiments of the
invention, additional spiral branch support sections may be located
at the first longitudinal coordinate or any other longitudinal and
circumferential coordinate. Moreover, the spiral side branch
support section 24 has only one spiral arm 28.
[0042] The outer support member 30 can have any shape, for example
a shape that corresponds to the cellular design of the primary
stent section 22, a circular shape, or a serpentine shape. The
outer support member 30 of FIGS. 2-13 has a circular shape. The
outer support member 30 of FIGS. 2-13 has at least one spiral arm
28 extending therefrom. If the spiral side branch section 24 has
circumferential members 34, the circumferential members 34 can have
any shape. In at least one embodiment, all the circumferential
members 34 have the same shape.
[0043] Any suitable stent geometry may be used for the main body of
the stent. The pattern of interconnected serpentine bands 19 shown
is shown by way of example only. The struts that form the
serpentine band may be straight as shown in FIG. 1 or may be bent.
The stent of FIG. 14 shows straight and bent struts.
[0044] If the spiral arm 28 has sufficient length, the spiral arm
28 will form a spiral around the opening 32 in the spiral side
branch section 24. Each spiral arm 28 has a distal end 50 and a
proximal end 52. The distal end 50 of the spiral arm 28 is
positioned closer to the center of the opening 32 of the spiral
side branch section 24 than the proximal end 52.
[0045] A non-bifurcated stent is formed when only the primary
branch section 22 is in an expanded state. A bifurcated stent is
formed when both the primary branch section 22 and the spiral side
branch section 24 are in an expanded state.
[0046] In FIG. 1, the primary branch section 22 and the spiral side
branch section 24 are shown in an unexpanded state. The spiral side
branch section 24 has an outer support member 30 and one spiral arm
28. The proximal end 52 of the spiral arm 28 is engaged to the
outer support member 30. The distal end 50 of the spiral arm 28 is
closer to the center of the opening 32 of the spiral side branch
section 24 than the proximal end 52.
[0047] More generally, the stent of FIG. 1 may have more than one
spiral side branch section. Where there is a plurality of side
branch sections, the side branches may be disposed at different
locations along the length of the stent, different circumferential
locations about the stent or both. Where a plurality of side branch
sections is present, the side branches may be of the same length or
of different lengths. The side branch sections may have only one
spiral arm per side branch section or one or more of the side
branch sections may each have a plurality of spiral arms.
[0048] The stent of FIG. 1 may prove to be advantageous as compared
with some of the known petal designs for bifurcated stents. In the
case of the latter stents, some of the petals typically have to be
bent at an angle in excess of 90 degrees resulting in high stresses
on those petals. No such extreme bending occurs during deployment
of the stent of FIG. 1 as well as during deployment of other stents
disclosed herein.
[0049] Another embodiment of the invention is shown at 20 in FIG.
2. Stent 20, shown in an expanded state, has a primary branch
section 22 and a spiral side branch section 24 that extends from
the primary branch section 22. The primary branch section 22 is a
substantially tubular body disposed about a longitudinal axis.
Those skilled in the art will recognize that the pattern of the
primary branch section 22 can have any cellular design. In some
embodiments of the invention, the primary branch section 22 may be
characterized as a substantially solid or porous tubular
member.
[0050] The expandable primary branch section 22 has a first
diameter in an unexpanded state (not shown) and a second diameter
in an expanded state. In an unexpanded state of the stent, the
entirety of the spiral side branch section 24 forms a part of the
surface of the substantially tubular body of the primary branch
section 22. The unexpanded version of the stent has only one
longitudinal flowpath and does not include a portion which branches
off of the longitudinal flowpath.
[0051] The spiral side branch section 24 has an outer support
member 30 and at least one spiral arm 28 that curves around an
opening 32 in the spiral side branch section 24.
[0052] In FIG. 2 the primary branch section 22 and the spiral side
branch section 24 are shown in an expanded state. The spiral side
branch section 24 of the stent 20 has an outer support member 30
and a plurality of spiral arms 28. The proximal end 52 of each
spiral arm 28 is engaged to the outer support member 30. When the
spiral side branch section 24 is in an expanded state the spiral
arms 28 form a plurality of helices depending upon the number of
spiral arms 28.
[0053] Another embodiment of the invention is shown in an
unexpanded state in side view in FIG. 3. In the embodiment of FIG.
3, the primary branch section 22 and the spiral side branch section
24 are shown in an unexpanded state. The spiral side branch section
24 has an outer support member 30, a plurality of spiral arms 28
and a circumferential member 34. The shape of the circumferential
member 34 is a 5 point star. The proximal ends 52 of the spiral
arms 28 are engaged to the outer support member 30. The distal ends
50 of the spiral arms 28 may be engaged to the circumferential
member 34 either at the apexes of the star shaped circumferential
member 34 or between the apexes of the star shaped circumferential
member 34.
[0054] Further as shown in FIG. 3, the spiral arms 28 are engaged
to the circumferential member 34 at the apexes 31. In addition, the
circumferential member 34 bounds a first area 58 in an unexpanded
state. The first area 58 is smaller than the area bounded by the
circumferential member 34 in an expanded state.
[0055] Another embodiment of the invention is shown in side view in
FIG. 4. In the embodiment of FIG. 4, the primary branch section 22
and the spiral side branch section 24 are shown in an unexpanded
state. Spiral side branch section 24 includes a circumferential
member 34 that is a 6 point star.
[0056] The invention is also directed to a stent having a side wall
with a plurality of openings therethrough, at least one of the
openings being in the form of a star-shaped opening bounded by a
star shaped member. The star-shaped opening may be a star with
three to nine points, as shown by way of example in FIG. 3 by a
five pointed star, or a six pointed star shown in FIG. 4.
Typically, there will be additional expandable structure connecting
the star shaped structure to the remainder of the stent. The
additional structure is configured to be expandable to form a side
branch.
[0057] The stent typically will have the star shaped opening in the
unexpanded state. Desirably, the stent may be expanded to form a
main body and a side branch extending therefrom. The side branch
may be formed by disposing a balloon catheter through the side
branch terminating in the star shaped opening and inflating the
balloon. Where the stent is self-expanding, the side branch
structure may be allowed to self-expand.
[0058] In the embodiment of FIG. 5, the primary branch section 22
and the spiral side branch section 24 are shown in an unexpanded
state. The spiral side branch section 24 has an outer support
member 30 and a plurality of spiral arms 28. The proximal ends 52
of the spiral arms are engaged to the outer support member 30. The
distal ends 50 of the spiral arms 28 are free ends.
[0059] In one or more embodiments, the invention is directed to a
stent comprising a plurality of spiral arms with free ends, as
shown by way of example in FIG. 5. The stent may be in an
unexpanded or expanded state (not shown). In an expanded state, the
free ends extend outward from a main body of the stent and form a
side branch.
[0060] In the embodiment of FIG. 6, the primary branch section 22
and the spiral side branch section 24 are shown in an unexpanded
state. The spiral side branch section 24 has an outer support
member 30, a plurality of spiral arms 28 and a circumferential
member 34 with a serpentine shape that has turns 36. The proximal
ends 52 of the spiral arms 28 are engaged to the outer support
member 30. The distal ends 50 of the spiral arms 28 are engaged to
the circumferential member 34 between the turns 36. Alternatively
the distal ends 50 of the spiral arms 28 may be engaged to the
circumferential member 34 at the turns 36. The circumferential
member 34 has first diameter 58 in an unexpanded state as measured
by the distance between opposite turns. The first diameter 58 is
smaller than the diameter of the circumferential member 34 in an
expanded state.
[0061] The invention is also directed to a stent having a side
branch section 24 with alternating ring members 34 and spiral arms
28 between the alternating ring members 34, as shown by way of
example in FIGS. 7 and 14. The embodiment in FIG. 14 shows a side
branch with three concentric rings 34a,b,c and three sets of spiral
arms 28a,b,c. It is within the scope of the embodiment to have more
than three concentric rings and three sets of spiral arms. In the
embodiment of FIG. 7 the primary branch section 22 and the spiral
side branch section 24 are shown in an unexpanded state. The spiral
side branch section 24 has an outer support member 30, a plurality
of spiral arms 28a, each spiral arm having a distal end 50a and a
proximal end 52a, a circumferential member 34a with a serpentine
shape that has turns 36, a plurality of spiral arms 28b, each
spiral arm 28b having a distal end 50b and a proximal end 52b, and
a circumferential member 34b with a serpentine shape that has turns
36.
[0062] The proximal ends 52a of the spiral arms 28a are engaged to
the outer support member 30. The distal ends 50a of the spiral arms
28a are engaged to the turns 36 of the circumferential member 34a.
The proximal ends 52b of the spiral arms 28b are engaged to the
circumferential member 34a between the turns 36. The distal ends
50b of the spiral arms 28b are engaged to the circumferential
member 34b at the turns 36.
[0063] In the embodiment of FIG. 14, the primary branch section 22
and the spiral side branch section 24 are shown in an unexpanded
state. The spiral side branch section 24 has an outer support
member 30, a plurality of spiral arms 28a, each spiral arm having a
distal end 50a and a proximal end 52a, a circumferential member 34a
with a serpentine shape that has turns 36, a plurality of spiral
arms 28b, each spiral arm 28b having a distal end and a proximal
end, a circumferential member 34b with a serpentine shape that has
turns 36, a plurality of spiral arms 28c, each spiral arm 28c
having a distal end and a proximal end.
[0064] The proximal ends 52a of the spiral arms 28a are engaged to
the outer support member 30. The distal ends 50a of the spiral arms
28a are engaged to the turns 36 of the circumferential member 34a.
The proximal ends of the spiral arms 28b are engaged to the turns
36 of the circumferential member 34a. The distal ends of the spiral
arms 28b are engaged to the turns 36 of the circumferential member
34b. The proximal ends of the spiral arms 28c are engaged to the
turns 36 of the circumferential member 34b. The distal ends of the
spiral arms 28c are engaged to the turns of the circumferential
member 34c. FIG. 15 shows the embodiment of the spiral branch
section in FIG. 14 in an expanded state.
[0065] In at least one embodiment, there is an intermediate ring 34
with peaks and troughs in the unexpanded state, such as is depicted
in FIG. 14. The troughs are connected to the peaks of the outer
ring. The peaks are connected to the inner ring. The curvature of
the peaks and troughs is similar between rings.
[0066] The invention is also directed to a stent having a side
branch section 24 with a plurality of interconnected spiral arms
that extend in a pinwheel fashion around a center point, as shown
by way of example in FIG. 16. The spiral side branch section 24 has
an outer support member 30, a plurality of spiral arms 28, each
spiral arm having a distal end 50 and a proximal end 52 and a
plurality of connectors 38. The plurality of connectors 38 engage
the proximal ends 52 of the spiral arms 28 to the outer support
member 30 and the plurality of connectors 38 interconnect the
spiral arms 28 at a plurality of locations. In this embodiment
there are eight spiral arms 28, however there can be more than
eight spiral arms 28. FIG. 17 shows the spiral side branch
embodiment of FIG. 16 in an expanded state.
[0067] In the embodiment of FIG. 8a, the primary branch section 22
and the spiral side branch section 24 are shown in an unexpanded
state. The spiral side branch section 24 has an outer support
member 30, a plurality of spiral arms 28, each spiral arm having a
distal end 50 and a proximal end 52, a circumferential member 34
and a locking mechanism 42. The circumferential member 34 has a
first diameter 58 in an unexpanded state. The first diameter 58 is
smaller than the diameter of the circumferential member 34 in an
expanded state. The locking mechanism 42 only allows the
circumferential member 34 to open in one direction. An example of a
suitable locking mechanism is shown by way of example in FIG. 8b.
FIG. 8b shows a tongue 103 and groove 101 mechanism. The mechanism
is shown in FIG. 8c immediately prior to engagement.
[0068] In the embodiment of FIG. 9, the primary branch section 22
and the spiral side branch section 24 are shown in an unexpanded
state. The circumferential member 34 of the spiral side branch
section 24 of FIG. 8a has a radiopaque marker 48. The radiopaque
marker 48 allows a practitioner to advance the stent 20 to the
bifurcation 10 and visually align the spiral side branch section 24
of the stent 20 with the branch vessel 14 using fluoroscopy or
other means. The radiopaque marker 48 may be comprise any suitable
radiopaque material.
[0069] The invention is also directed to a bifurcated stent having
a main branch and a side branch extending from the main branch. The
side branch includes a lock. The lock may be configured to lock the
side branch in an expanded configuration.
[0070] The invention is also directed to a stent having a sidewall
with an iris-shaped structure. Examples of such are shown in FIGS.
3-9 where the side branch section 24 forms the iris shaped
structure. In some embodiments, the iris-shaped structure will be
present in the unexpanded state of the stent. The iris-shaped
structure will desirably be expandable outward to form a side
branch having a flow path therethrough, the side branch extending
outward from a main flow path of the stent. The iris-shaped
structure may optionally comprise a plurality of curved members
such as the spiral arms disclosed above which together form a
spiral pattern about a center point. In some embodiments, the
curved members will be of equal length and/or shape.
[0071] In some embodiments, the curved members will have free ends.
This is shown by way of example in FIG. 5. Curved members in the
form of spiral arms 28 have one free end.
[0072] In other embodiments, one end of the curved arms will extend
from an outer ring-like pathway and the other end of the curved
arms will extend from an inner ring. An example of such a structure
is shown in FIG. 3. The inner ring structure is in the form of
circumferential member 34 which is a 5 pointed star while the outer
ring structure is in the form of an outer support member 30 which
is in the form of a circle. Another example of such is the stent of
FIG. 6. The curved arms are attached at one end to outer support
member 30 in the form of a circular structure. The curved arms are
attached at the other end to a first circumferential member 34a
which forms a propeller-like structure. The propeller-like
structure may also be described as being a substantially circular
structure with a plurality of folds extending therefrom. Stent 20
of FIG. 6 further includes a second propeller-like structure
extending from the first propeller-like structure.
[0073] In the embodiment of FIGS. 10a and 10b, the spiral side
branch section 24 of FIG. 7 is in an expanded state. The
circumferential member 34 has an expanded diameter 60. When
expanded, the spiral arms 28 of the side branch section 24 either
can be straight as depicted in FIG. 10a or curved as depicted in
FIG. 10b.
[0074] In the embodiment of FIG. 11, the primary branch section 22
and the spiral side branch section 24 are shown in an unexpanded
state. The spiral side branch section 24 has an outer support
member 30 and a plurality of spiral arms 28d. The spiral arms 28d
have a width, length and proximal end 52. The embodiment shown in
FIG. 11 has four spiral arms 28d. The spiral arms 28d can have any
length. In this embodiment, all the spiral arms 28d in a spiral
side branch section 24 will have the same length. In at least one
embodiment, all the spiral arms 28d are not the same length. In
FIG. 11, the width of the spiral arms 28d is solid. In another
embodiment as shown in FIG. 12, the interior portion of the width
of the spiral arm 28d may have an opening 39 therethrough. In FIG.
13, the spiral side branch section 24 of FIG. 11 is in an expanded
state.
[0075] In yet another embodiment of the invention, a stent may be
provided with a side branch support section with one or more
self-expandable members extending therefrom. The self-expandable
member may be in the form of a shape memory wire whose memorized
shape is that of a coil. Any suitable shape memory material may be
used including nitinol. The wire may be coiled when in the
martensitic state and straightened and projecting outward in the
austenitic state with a transition temperature at or below body
temperature. The stent may be maintained in its straightened shape
via a sheath. Once the one or more wires are in the bifurcated
vessel, upon removal of the sheath, the one or more wires may
assume the form of a coil. The wires may be welded to the main body
of the stent or otherwise suitably attached thereto. It is within
the scope of the invention to include only one such wire per side
branch to be formed or to include two, three, four, five or more
wires per side branch location.
[0076] In another embodiment of the invention, the self-expanding
wires need not be attached to the main body of the stent. Rather,
the one or more wires may be delivered to the desired bodily
location once a primary stent, optionally balloon expandable, has
been delivered to the desired bodily location. The delivery of the
one or more wires to the side branch may also be simultaneous with
the delivery of the primary stent. Where two wires which form coils
are to be used, the wires may be arranged such that they form
counter-wound helices.
[0077] Any of the inventive stents disclosed herein may have a
uniform inner diameter and/or a uniform outer diameter in the
unexpanded state and/or in an expanded state. The inventive stents
disclosed herein may also be provided in an embodiment in which the
inner and/or outer diameters are not uniform. For example, one or
more portions of the stent may have a tapered outer diameter. The
main body may be tapered, the side branch may be tapered or both
may be tapered.
[0078] In any of the inventive stents disclosed herein, the spiral
side branch section may have one or more spiral arms. The spiral
side branch may be of uniform diameter when expanded or variable
diameter when expanded. As an example of the latter, the spiral
side branch, when expanded, may have a portion which tapers. The
spiral side branch may taper from a larger diameter at the
bifurcation to a smaller diameter further into the bifurcation
vessel.
[0079] In many of the embodiments shown in the figures, there is no
more than one spiral branch support section located in a given
circumferential section of the stent. In other embodiments of the
invention, additional spiral branch support sections may be located
within a given circumferential segment of the stent. The inventive
stents may also have multiple spiral branch support sections
disposed along the length of the stent.
[0080] Also, in many of the figures, portions of the inventive
stent are drawn without showing structure. It is understood that
any suitable structure may be employed including, but not limited
to, the cellular patterns, shown by way of example only, in U.S.
Pat. Nos. 6,835,203, 6348065, and 6013091.
[0081] At least some of the embodiments disclosed herein, for
example, that of FIG. 1, are advantageous in that they do not
require the spiral arms to be bent back at angles in excess of 90
degrees when the side branch is expanded. Many of the prior art
bifurcated stents which have petals will include petals which are
bent back in excess of 90 degrees when the side branch is
deployed.
[0082] At least some of the embodiments, for example, at least that
of FIG. 1, are advantageous in that, for a given length of starting
material (for example, a tubular blank), a longer side branch
section can be made via the use of spirals.
[0083] In at least one embodiment, the invention is directed to a
stent that has an expandable primary branch section and a
separately expandable spiral side branch section that forms a part
of the primary branch section. The expandable primary branch
section is a substantially tubular body disposed about a
longitudinal axis. The expandable primary branch section has a
first diameter in an unexpanded state and a second diameter in an
expanded state. The spiral side branch section has an unexpanded
state and an expanded state. In an unexpanded state the entirety of
the spiral side branch section forms a part of the surface of the
substantially tubular body of the primary branch section. Thus, the
spiral side branch section has the same uniform thickness as the
primary branch section. The spiral side branch section has an outer
support member and at least one spiral arm that curves around an
opening in the spiral side branch section. The outer support member
can have any shape, e.g. a shape that corresponds to the cellular
design of the primary stent section, a circular shape or a
serpentine shape. Each spiral arm has a proximal end and a distal
end. The distal end of the spiral arm is positioned closer to the
center of the opening of the spiral side branch support section
than the proximal end. A non-bifurcated stent is formed when the
primary branch section is in an expanded state and the spiral side
branch section is in an unexpanded state. A bifurcated stent is
formed when both the primary branch section and the spiral side
branch section are in an expanded state.
[0084] In at least one embodiment, the spiral side branch section
has only one spiral arm that expands into a coil when the spiral
side branch section is in an expanded state.
[0085] In at least one embodiment, the spiral side branch section
has a plurality of spiral arms. The distal ends of the spiral arms
expand into a helix or multiple helices when the spiral side branch
section is in an expanded state. The spiral design provides uniform
support and a custom fit for tapering vessels.
[0086] In at least one embodiment, the spiral side branch section
has a plurality of spiral arms and a circumferential member. The
circumferential member has a first diameter in an unexpanded state
and second diameter in an expanded state, the second diameter is
larger than the first diameter. A plurality of spiral arms is
engaged to the circumferential member. The circumferential member
can be any shape. Some shapes, such as a star, can have apexes and
valleys. If the shape has apexes and valleys, the spiral arms can
be engaged to the circumferential member at the apexes, at the
valleys, or anywhere in between. The circumferential member
provides support at the distal end of the spiral side branch
section.
[0087] In another embodiment the circumferential member has a
serpentine shape, which has turns. In one embodiment the plurality
of spiral arms are engaged to the circumferential member at the
turns. In another embodiment the plurality of spiral arms are
engaged to the circumferential member between the turns.
[0088] In at least one embodiment, the spiral side branch section
has a plurality of circumferential members and a plurality of
spiral arms. Each circumferential member can be any shape, but
preferably all the circumferential members of a particular spiral
side branch design have the same shape. Each circumferential member
has a first diameter in an unexpanded state that is different from
the first diameter of the other circumferential members, i.e. a
first diameter that is either larger or smaller than the first
diameter of the other circumferential members. The circumferential
members are arranged so that the circumferential member with the
smallest first diameter, the first circumferential member, is
located closest to the center of the spiral side branch opening and
the circumferential member with the largest first diameter, the nth
circumferential member, is located farthest away from the center of
the spiral side branch section opening. The circumferential members
are engaged to neighboring circumferential members by a plurality
of spiral arms.
[0089] In another embodiment there are two serpentine
circumferential members and a plurality of spiral arms. Each
serpentine circumferential member has a first diameter in an
unexpanded state. The first diameters of the two serpentine
circumferential members are different, one serpentine
circumferential member having a first diameter smaller than the
other serpentine circumferential member. The primary branch section
can be engaged to an outer support member of the spiral side branch
section. The outer support member is engaged to the proximal ends
of some of the plurality of spiral arms. The distal ends of some of
the plurality of spiral arms are engaged to the circumferential
member with the largest first diameter at the apexes of the curved
undulations. The proximal ends of some of the plurality of spiral
arms are engaged to the valleys of the first circumferential
member. The distal ends of the second set of spiral arms are
engaged to the apexes of the curved undulations of the
circumferential member with the smaller first diameter. The
multiple circumferential members provide circumferential support at
multiple locations of the side branch lumen while the spiral arms
provide flexibility and good conformability at difficult lesion
areas.
[0090] In at least one embodiment, the spiral side branch section
has a circumferential member, a plurality of spiral arms and a
locking mechanism. The primary stent section can be engaged to an
outer support member of the spiral side branch section. The outer
support member is engaged to the circumferential member by a
plurality of spiral segments where at least one of the spiral arms
is held in place to the circumferential member by a locking
mechanism. The circumferential member can be any shape. The locking
mechanism allows the rings to open in only one direction. The
locking center ring provides distal support for the side branch
lumen.
[0091] In at least one embodiment, the spiral side branch has at
least three spiral arms. The spiral arms have a width, a length and
an apex. The spiral arms may be self- expanding or balloon
expandable. The length of the spiral arms can vary but preferably
all the spiral arms in a spiral side branch section will have the
same length. In another embodiment, there may be an opening within
the width of the spiral arm.
[0092] The inventive stents may be deployed to a desired bodily
location by a catheter. The inventive stent may be disposed about a
catheter. If a bifurcated stent is desired, the catheter used to
deliver the stent can have an elongated member that extends through
the opening of the side branch section of the stent. The elongated
member may be a guide wire, a catheter tube or a balloon. The
catheter is used to advance the stent to the desired bodily
location.
[0093] The invention is also directed to any of the inventive
stents disclosed here in combination with or disposed about a
delivery catheter. Optionally, the delivery catheter may include a
first guide wire extending along the longitudinal flow path of the
main body of the stent and a second guide wire extending out
through the side branch support section.
[0094] The inventive stents may be made from any suitable
biocompatible materials including one or more polymers, one or more
metals or combinations of polymer(s) and metal(s). Examples of
suitable materials include biodegradable materials that are also
biocompatible. Biodegradable means that a material will undergo
breakdown or decomposition into harmless compounds as part of a
normal biological process. Suitable biodegradable materials include
polylactic acid, polyglycolic acid (PGA), collagen or other
connective proteins or natural materials, polycaprolactone,
hylauric acid, adhesive proteins, co-polymers of these materials as
well as composites and combinations thereof and combinations of
other biodegradable polymers. Other polymers that may be used
include polyester and polycarbonate copolymers. Examples of
suitable metals include, but are not limited to, stainless steel,
titanium, tantalum, platinum, tungsten, gold and alloys of any of
the above-mentioned metals. Examples of suitable alloys include
platinum-iridium alloys, cobalt-chromium alloys including Elgiloy
and Phynox, MP35N alloy and nickel-titanium alloys, for example,
Nitinol.
[0095] The inventive stents may be made of shape memory materials
such as superelastic Nitinol or spring steel, or may be made of
materials which are plastically deformable. In the case of shape
memory materials, the stent may be provided with a memorized shape
and then deformed to a reduced diameter shape. The stent may
restore itself to its memorized shape upon being heated to a
transition temperature and having any restraints removed
therefrom.
[0096] The inventive stents may be manufactured by methods
including cutting or etching a design from a tubular stock or from
a flat sheet. In the latter case, the sheet may be rolled into a
stent and the edges optionally joined together via welding, gluing
or any other suitable technique. The stent may also be made by
fabricating individual portions of the stent and then joining the
portions together. For example, the main portion of the stent and
the side branch portion may be separately manufactured and then
joined together via welding, the use of adhesives or any other
suitable technique. The stent may also be manufactured by any other
suitable technique known in the art or subsequently developed.
[0097] The invention is also directed to the manufacture of the
inventive stents disclosed herein. To that end, the invention is
directed to a method comprising the steps of providing a tube or
sheet of stent material and cutting any of the inventive stent
patterns disclosed herein into the tube or sheet. In the case of a
sheet, the edges of the sheet may optionally be joined together.
The resulting tube with the stent pattern may then be subject to
standard polishing and cleaning steps as know in the art.
[0098] The invention is also directed to treatment methods using
any of the inventive stents disclosed herein. To that end, any of
the inventive stents disclosed herein may be disposed about a stent
delivery catheter. The catheter may be inserted in a bodily lumen
and delivered to a desired bodily location, typically a region with
a bifurcation. In the case of a balloon catheter, the stent may be
expanded with a single balloon or with a plurality of balloons. In
the former case, a blister balloon may be used to expand both the
main branch of the stent as well as the side branch. In the latter
case, a second balloon could be used to at least partially expand
the side branch section of the stent into a bifurcation in a vessel
and, optionally, yet another balloon could be used to fully expand
the side branch. In some embodiments, a special guide wire may be
used to initiate the side branch section into the bifurcation and a
balloon then used to expand the side branch section. In the case of
a self-expanding stent, a sheath or other restrain may be removed
allowing the stent to self expand. In the case of hybrid stents, a
balloon may be used to expand a portion of the stent and a sheath
or other restrain withdraw from a portion of the stent. Subsequent
to deployment of the stent, the catheter may be withdrawn from the
body.
[0099] In some embodiments the stent, the delivery system or other
portion of the assembly may include one or more areas, bands,
coatings, members, etc. that may be detected by imaging modalities
such as X-Ray, MRI, ultrasound, etc. In some embodiments, at least
a portion of the stent and/or adjacent assembly is at least
partially radiopaque. A radiopaque marker on the outer support
member may facilitate placement of the stent. Optionally, a marker
could be located at the spiral side branch section of the stent at
a bifurcation. Similarly, a radiopaque marker on the distal end of
at least one spiral arm may facilitate placement of the spiral side
branch section of the stent at a bifurcation.
[0100] In some embodiments, the stent or portions thereof may
include one or more mechanisms for the delivery of a therapeutic
agent. In one embodiment, the side branch section may be provided
with the therapeutic agent. Often the agent will be in the form of
a coating or other layer (or layers) of material placed on a
surface region of the stent, which is adapted to be released at the
site of the stent's implantation or areas adjacent thereto.
[0101] A therapeutic agent may be a drug or other pharmaceutical
product such as non-genetic agents, genetic agents, cellular
material, etc. Some examples of suitable non-genetic therapeutic
agents include but are not limited to: anti-thrombogenic agents
such as heparin, heparin derivatives, vascular cell growth
promoters, growth factor inhibitors, Paclitaxel, etc. Where an
agent includes a genetic therapeutic agent, such a genetic agent
may include but is not limited to: DNA, RNA and their respective
derivatives and/or components; hedgehog proteins, etc. Where a
therapeutic agent includes cellular material, the cellular material
may include but is not limited to: cells of human origin and/or
non-human origin as well as their respective components and/or
derivatives thereof. Where the therapeutic agent includes a polymer
agent, the polymer agent may be a
polystyrene-polyisobutylene-polystyrene triblock copolymer (SIBS),
polyethylene oxide, silicone rubber and/or any other suitable
substrate.
[0102] The invention also includes the following embodiments as
characterized in the following numbered statements:
[0103] 1. In combination, a catheter and an expandable stent having
a tubular surface disposed about a longitudinal flowpath, the
tubular surface including at least one arm which is arranged along
the surface about an opening, the opening having a first size in an
unexpanded state of the stent, the at least one arm arranged to
define a spiral, the expandable stent disposed about the catheter,
the catheter including an elongated member which extends through
the opening.
2. The combination of statement 1 wherein the elongated member
comprises a guide wire.
3. The combination of statement 1 wherein the elongated member
comprises a catheter tube.
4. The combination of statement 1 wherein the elongated member
comprises a balloon.
5. A stent having a side wall with a plurality of openings
therethrough, at least one of the openings being in the form of a
star-shaped opening bounded by a star shaped member.
6. The stent of statement 5 wherein the star-shaped opening is a
three pointed to a nine pointed star.
7. The stent of statement 5 wherein the star-shaped opening is a
five pointed star.
8. The stent of statement 5 wherein the star-shaped opening is a
six pointed star.
9. The stent of statement 5 wherein the star-shaped opening is
bounded by a star shaped structure.
10. The stent of statement 5 wherein two of the openings are
bounded by a star shaped member, the first star shaped member
having a shorter pathway than the second star shaped member.
11. The stent of statement 5 in an expanded state, the stent having
a main branch and a side branch extending therefrom.
12. A bifurcated stent formed by inserting an elongated member
through the stent and inserting an elongated member through the
star shaped opening, expanding the stent so as to create a side
branch and a main branch.
13. A stent comprising a plurality of spiral arms with free
ends.
14. The stent of statement 13 in an expanded state, the free ends
extending outward from a main body of the stent and forming a side
branch.
15. The stent of statement 13 having an inner diameter and an outer
diameter, the inner diameter being constant along the length of the
stent and the outer diameter being constant along the length of the
stent.
16. The stent of statement 13 wherein the spiral arms lie flush
along the surface of the stent.
17. The stent of statement 13 in an unexpanded state wherein the
spiral arms spiral about a common center point.
18. A bifurcated stent having a main branch and a side branch
extending from the main branch, the side branch including a
lock.
19. The stent of statement 18 wherein the lock may be configured to
lock the side branch in an expanded configuration.
20. A stent having a side wall with an iris-shaped structure.
21. The stent of statement 20 wherein the iris-shaped structure is
present in the unexpanded state of the stent.
22. The stent of statement 21 wherein the iris-shaped structure may
be expandable outward to form a bifurcated stent having a side
branch.
23. The stent of statement 22 wherein the iris-shaped structure
comprises a plurality of curved members which together form a
spiral pattern about a center point.
24. The stent of statement 23 wherein the curved members will be of
equal length and/or shape.
25. The stent of statement 23 wherein the curved members each have
free ends.
26. The stent of statement 23 wherein the iris shaped structure
includes an outer ring and an inner ring, the outer ring disposed
about the inner ring.
27. The stent of statement 26 wherein the inner ring is star
shaped.
28. The stent of statement 26 wherein the inner ring is sized to
receive a balloon catheter therethrough.
29. The stent of statement 26 comprising a plurality of concentric
inner rings.
30. A stent having a side wall with an outer support member with
spiral members extending therefrom.
31. A stent having a side wall with a plurality of interconnected
members that extend in a pinwheel fashion around a center
point.
32. A stent having a side wall with alternating ring members and
spiral arms.
[0104] 33. A stent having a single longitudinal flowpath extending
in the longitudinal direction, the stent comprising a plurality of
spiral members which are configured to be expanded outward to
define a second flowpath which branches outward from the
longitudinal flowpath.
34. A bifurcated stent made by providing the stent of statement 33
and expanding the plurality of spiral members outward.
35. The bifurcated stent of statement 34 wherein in an unexpanded
state, the spiral members are formed in a helical pattern and in an
expanded state, the spiral members are straight.
36. The bifurcated stent of statement 34 wherein in an unexpanded
state, the spiral members are formed in a helical pattern and in an
expanded state, the spiral members are curved.
37. In combination, any of the stents of statements 4-32 and a
catheter, the stent disposed about the catheter.
38. A stent delivery catheter with any of the stents of statements
4-32 disposed thereabout.
39. A stent delivery catheter with any of the stents of statements
4-32 disposed at a distal end portion of the catheter.
40. A method of manufacturing a stent comprising the steps of:
[0105] providing a tube having a sidewall;
[0106] removing material from the sidewall of tube, the remaining
material of the sidewall of the tube forming a stent pattern, the
remaining material including at least one spiral portion, the
spiral portion including at least one spiral arm having a free
end.
41. The method of statement 40 further comprising the steps of:
[0107] expanding the tube; and
[0108] expanding the spiral portion so as to form a side branch
with a lumen that extends at angle from the tube.
42. A method of manufacturing a stent comprising the steps of:
[0109] providing a tube having a sidewall;
[0110] removing material from the sidewall of tube, the remaining
material of the sidewall of the tube forming a stent pattern, the
remaining material including at least one spiral portion and no
more than one spiral portion at a given longitudinal location along
the tube, the spiral portion including at least one spiral arm.
43. The method of statement 42 further comprising the steps of:
[0111] expanding the tube; and
[0112] expanding the spiral portion so as to form a side branch
with a lumen that extends at angle from the tube.
44. A method of manufacturing a stent comprising the steps of:
[0113] providing a tube having a sidewall;
[0114] removing material from the sidewall of tube, the remaining
material of the sidewall of the tube forming a stent pattern, the
remaining material including at least one spiral portion, the
spiral portion including a plurality of concentric, closed pathways
each of which extends only part of the way about the longitudinal
axis of the tube, the closed pathways connected one to the other
via spiral arms which together form one or more spiral
configurations.
45. The method of statement 44 further comprising the steps of:
[0115] expanding the tube; and
[0116] expanding the spiral portion so as to form a side branch
with a lumen that extends at angle from the tube.
[0117] The above disclosure is intended to be illustrative and not
exhaustive. This description will suggest many variations and
alternatives to one of ordinary skill in this art. The various
elements shown in the individual figures and described above may be
combined or modified for combination as desired. All these
alternatives and variations are intended to be included within the
scope of the claims where the term "comprising" means "including,
but not limited to".
[0118] Further, the particular features presented in the dependent
claims can be combined with each other in other manners within the
scope of the invention such that the invention should be recognized
as also specifically directed to other embodiments having any other
possible combination of the features of the dependent claims. For
instance, for purposes of claim publication, any dependent claim
which follows should be taken as alternatively written in a
multiple dependent form from all prior claims which possess all
antecedents referenced in such dependent claim if such multiple
dependent format is an accepted format within the jurisdiction
(e.g. each claim depending directly from claim 1 should be
alternatively taken as depending from all previous claims). In
jurisdictions where multiple dependent claim formats are
restricted, the following dependent claims should each be also
taken as alternatively written in each singly dependent claim
format which creates a dependency from a prior
antecedent-possessing claim other than the specific claim listed in
such dependent claim below.
[0119] This completes the description of the invention. Those
skilled in the art may recognize other equivalents to the specific
embodiment described herein which equivalents are intended to be
encompassed by the claims attached hereto.
* * * * *