U.S. patent application number 10/651557 was filed with the patent office on 2004-06-10 for balloon catheter with non-deployable stent.
Invention is credited to Farnan, Robert C..
Application Number | 20040111108 10/651557 |
Document ID | / |
Family ID | 34273385 |
Filed Date | 2004-06-10 |
United States Patent
Application |
20040111108 |
Kind Code |
A1 |
Farnan, Robert C. |
June 10, 2004 |
Balloon catheter with non-deployable stent
Abstract
An angioplasty balloon including a non-deployable stent to
prevent or reduce the potential for slippage of the inflated
balloon with respect to the vessel wall being treated. The balloon
includes a non-deployable stent that is adapted to be secured to
the balloon or angioplasty balloon catheter. The stent has a
proximal end, a distal end, and at least one extension section, at
least one set of serpentine rings and at least one set of
elongation links that allow expansion of the strut to accommodate
the inflation of the balloon. The stent is made of a material so
that the stent collapses upon deflation of the balloon.
Inventors: |
Farnan, Robert C.; (Davie,
FL) |
Correspondence
Address: |
COOK, ALEX, MCFARRON, MANZO, CUMMINGS & MEHLER LTD
SUITE 2850
200 WEST ADAMS STREET
CHICAGO
IL
60606
US
|
Family ID: |
34273385 |
Appl. No.: |
10/651557 |
Filed: |
August 29, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10651557 |
Aug 29, 2003 |
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10399589 |
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10399589 |
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PCT/US02/35547 |
Nov 6, 2002 |
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60344982 |
Nov 9, 2001 |
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Current U.S.
Class: |
606/194 ;
623/1.16 |
Current CPC
Class: |
A61F 2/91 20130101; A61M
25/104 20130101; A61M 2025/1088 20130101; A61F 2210/0076 20130101;
A61F 2230/0067 20130101; A61F 2002/91525 20130101; A61F 2230/005
20130101; A61M 2025/109 20130101; A61F 2002/91558 20130101; A61B
2017/22061 20130101; A61M 25/1027 20130101; A61B 2017/00858
20130101; A61M 2025/1081 20130101; A61F 2/915 20130101; A61F
2230/0058 20130101; A61F 2002/91533 20130101; A61M 2025/1086
20130101; A61M 2025/105 20130101; A61F 2/958 20130101; A61B
17/320725 20130101; A61M 25/10 20130101 |
Class at
Publication: |
606/194 ;
623/001.16 |
International
Class: |
A61M 029/02 |
Claims
What is claimed:
1. A non-deployable stent adapted to be secured to an angioplasty
balloon catheter comprising: a proximal end; a distal end; at least
one extension section, at least one set of serpentine rings and at
least one set of elongation links connecting the proximal end to
the distal end, to allow expansion of the stent to accommodate the
inflation of the balloon; and the stent being made of a material
having a memory so that the stent collapses upon deflation of the
balloon.
2. The stent of claim 1 wherein the stent is made of an alloy of
nickel and titanium.
3. The stent of claim 1 wherein one extension section is located on
the proximal end of the stent and another extension section is
located on the distal end of the stent.
4. The stent of claim 1 comprising at least three sets of
serpentine rings.
5. The stent of claim 4 wherein a set of elongation links is
located between said sets of serpentine rings.
6. The stent of claim 1 wherein said serpentine rings have a
serpentine shape.
7. The stent of claim 1 wherein said elongation links have a Z
shape.
8. The stent of claim 1 wherein said elongation links have a
zig-zag shape.
9. The stent of claim 1 wherein the stent is made of a laser-cut
hypotube.
10. The stent of claim 1 wherein at least one end of the stent is
secured to the balloon using an anchoring means.
11. The stent of claim 1 wherein said anchoring means is an
adhesive.
12. The stent of claim 11 wherein the adhesive is a UV
adhesive.
13. The stent of claim 11 wherein said anchoring means is selected
from the group consisting of RF heat welding, solvent bonding,
crimping at least one ends of the stent, swaging at least one end
of the stent, and using a small sleeve mounted over at least one
end of the stent and heat welded together where the end of the
stent is sandwiched between the catheter and the sleeve.
14. The stent of claim 1 further comprising cage mounted flanges at
the proximal end and the distal end.
15. The stent of claim 1 comprising four sets of serpentine rings
and three sets of elongation links, wherein each set of elongation
links is located between said sets of serpentine rings.
16. The stent of claim 15 wherein said elongation links have a z
shape.
17. The stent of claim 16 wherein said stent is made of an alloy of
nickel and titanium.
18. An angioplasty balloon catheter comprising: an
inflatable/deflatable balloon having a proximal end and a distal
end; and a non-deployable stent adapted to be secured to the
balloon comprising a proximal end; a distal end; an extension
section on said proximal end and an extension section on said
distal end; at least two sets of serpentine rings, with a set of
elongation links located between said sets of serpentine rings,
between said expansion sets, said extension sections, said sets of
serpentine rings and said set of elongation links allow expansion
of the stent to accommodate the inflation of the balloon; and the
stent being made of a material having a memory so that the stent
collapses upon deflation of the balloon.
19. The angioplasty balloon of claim 18 wherein the stent is made
of an alloy of nickel and titanium.
20. The angioplasty balloon of claim 18 wherein the stent is made
of a laser-cut hypotube.
21. The angioplasty balloon of claim 18 wherein at least one end of
the stent is secured to the balloon using an anchoring means.
22. The stent of claim 21 wherein said anchoring means is an
adhesive.
23. The stent of claim 22 wherein the adhesive is a UV
adhesive.
24. The stent of claim 21 wherein said anchoring means is selected
from the group consisting of RF heat welding, solvent bonding,
crimping at least one ends of the stent, swaging at least one end
of the stent, and using a small sleeve mounted over at least one
end of the stent and heat welded together where the end of the
stent is sandwiched between the catheter and the sleeve.
25. The stent of claim 18 further comprising cage mounted flanges
at the proximal end and distal end.
26. The stent of claim 18 comprising four sets of serpentine rings
and three sets of elongation links, wherein each set of elongation
links is located between said sets of serpentine rings.
27. The stent of claim 26 wherein said elongation links have a z
shape.
28. The stent of claim 27 wherein said stent is made of an alloy of
nickel and titanium.
Description
[0001] This application is a continuation-in-part of co-pending
U.S. application Ser. No. 10/399,589 filed on Apr. 18, 2003 which
is the U.S. national stage of PCT application no. PCT/US02/35547
filed Nov. 6, 2002 which claims the benefit of U.S. provisional
60/344,982 filed Nov. 9, 2001.
BACKGROUND OF THE INVENTION
[0002] When a balloon used for percutaneous transluminal
angioplasty (PTA) or percutaneous transluminal coronary angioplasty
(PTCA) is inflated and forced into contact with the plaque, the
balloon can have a tendency to move or slip longitudinally in
relation to the lesion or the vessel wall being treated.
[0003] Cutting balloons (atherotomy) have recently shown clinical
efficacy in preventing the reoccurrence of some types of restenosis
(specifically calcified lesions and in-stent restenosis). The
cutting balloon is a coronary dilatation catheter with 3 to 4
atherotomes (microsurgical blades) bonded longitudinally on the
balloon surface. As the cutting balloon is inflated, the
atherotomes move radially and open the occluded artery by incising
and compressing the arterial plaque in a controlled manner. An
additional advantage of the cutting balloon is that it maintains
its position during inflation by using the metal blades on the
external surface of the balloon to penetrate into the tissue and
prevent the balloon from moving.
[0004] Accordingly, it is the principal objective of the present
invention to provide a PTA or PTCA balloon that, like a cutting
balloon, has a reduced potential of slippage when inflated in a
vessel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a perspective view of an inflated angioplasty
balloon incorporating a non-deployable stent according to the
present invention.
[0006] FIG. 2 is a plan view of the inflated angioplasty balloon
and non-deployable stent of FIG. 1.
[0007] FIG. 3 is a perspective view of the non-deployable stent in
its expanded condition, as shown in FIG. 1, with the angioplasty
balloon removed so as to more clearly show the stent.
[0008] FIG. 4 is a plan view of the non-deployable stent of FIG.
3.
[0009] FIG. 5 is a perspective view of an alternate embodiment of
the non-deployable stent associated with an angioplasty balloon
that has a longer working length than the angioplasty balloon shown
in FIGS. 1 and 2.
[0010] FIG. 6 is an engineering drawing showing, in plan view, the
layout of a non-deployable stent adapted to be used with an
angioplasty balloon of 20 mm in length. (All dimensions shown in
the drawing are in inches.)
[0011] FIG. 7 is a perspective view of an inflated angioplasty
balloon incorporating an alternative embodiment of a non-deployable
stent which does not include any connecting elements between the
struts intermediate the ends of the balloon.
[0012] FIG. 8 is a perspective view of the non-deployable stent
shown in FIG. 7, with the angioplasty balloon removed so as to more
clearly show the stent.
[0013] FIGS. 9 and 10 are perspective views similar to FIGS. 1, 5,
and 7 showing a further embodiment of the invention.
[0014] FIG. 11 is a perspective view of a further embodiment of the
present invention showing the balloon and non-deployable stent in
conjunction with a catheter.
[0015] FIG. 12 is an engineering drawing showing, in plan view, the
layout of another embodiment of a non-deployable stent adapted to
be used with an angioplasty balloon, in accordance with the present
invention.
[0016] FIG. 13 an engineering drawing showing, in plan view, the
layout of an alternate non-deployable stent of the embodiment of
FIG. 12.
DESCRIPTION
[0017] The non-deployable stent of the present invention may be
used in conjunction with a conventional balloon catheter. A PTA or
PTCA catheter (dilatation catheter) may be a coaxial catheter with
inner and outer members comprising a guide wire lumen and a balloon
inflation lumen, respectively. Each member can have up to 3 layers
and can be reinforced with braids. The proximal end of the catheter
has a luer hub for connecting an inflation means, and a strain
relief tube extends distally a short distance from the luer hub.
The distal ends of the outer and inner members may include a taper.
The catheter shaft is built using conventional materials and
processes. A catheter having multi-durometer tubing with variable
stiffness technology is also a possibility. The catheter should be
compatible with standard sheaths and guide catheters which are well
known in the art. Optionally, the catheter may be a multi-lumen
design.
[0018] The balloon 1 may be made of either nylon or nylon copolymer
(compliant, non-puncture) or PET (high pressure, non-compliant)
with a urethane, polymer, or other coating known in the art to
provide tackiness and/or puncture resistance. The balloon may be a
multi-layered balloon with a non-compliant inner layer to a most
compliant outer layer. For example, a inner most layer of PET,
which provides a higher pressure balloon, surrounded by an outer
layer of nylon, which provides a more puncture-resistant surface.
The balloon may be from 1.5-12 mm in diameter (1.5-4 mm for
coronary and 4-12 mm for peripheral vessels) and 15-60 mm in length
(5-40 mm for coronary and up to 60 mm for peripheral vessels). The
balloon inflation rated pressure will be from 8-20 atmospheres,
depending on the wall thickness of the balloon. When inflated, the
balloon ends or necks are cone-shaped.
[0019] In keeping with the invention, the balloon is provided with
a Nitinol (NiTi) or another material such as for example liquid
metal, stainless steel, or other similar material, structure,
generally designated 2, that incorporates bends for both radial and
longitudinal expansion of the Nitinol structure 2 in response to
longitudinal and radial expansion of the balloon during inflation,
so that the Nitinol structure 2 maintains the balloon in its
intended position during inflation. This Nitinol structure 2 can be
described as a non-deployable or temporary stent that provides for
both controlled cracking of vessel occlusion and gripping of vessel
wall during an angioplasty procedure. The Nitonol structure 2
comprises a laser cut hypo tube that expands upon inflation of the
balloon, but collapses upon deflation of the balloon because of the
super-elastic properties of the Nitinol material, rather than
remain expanded in the deployed condition, as would stents in
general.
[0020] The Nitinol structure or non-deployable stent 2 has a
proximal end 3, a distal end 4, and, therebetween, anywhere from
3-12 struts or wires 5 (depending on balloon size--but most likely
3-4 struts) with a pattern of radial and longitudinal bends. The
use of laser cutting in connection with stent manufacture is well
known (See, e.g., Meridan et al. U.S. Pat. No. 5,994,667), as is
the use of the super-elastic nickel-titanium alloy Nitinol (see
e.g., Huang et al. U.S. Pat. No. 6,312,459).
[0021] As seen in FIGS. 1-4, each end of the four struts 5 has a
sinusoidal type bend 6 that allows the laser cut hypo tube to
expand longitudinally when the balloon 1 is inflated. The linear
length of the sinusoidal type bends 6 is sized to accommodate the
longitudinal expansion of the balloon 1 due to inflation. The strut
or wire 5 cross sectional shape can be round, triangular,
elliptical, oval, or rectangular. Preferred thickness of the struts
5 ranges from 0.003 to 0.010 inch.
[0022] At the longitudinal center of the hypo tube, a U-shaped
circumferential connector 7 joins each strut 5 to its adjacent
strut. As best seen in FIGS. 3 and 4, the U-shaped connectors 7 are
on opposing sides of the central radial axis. The distal end 4 of
the hypo tube is adhered to the distal neck of the balloon or the
distal end of the catheter shaft, and the proximal end 3 of the
hypo tube is either attached to the proximal neck of the balloon or
to the proximal end of the catheter shaft. The struts 5 may be
attached to the working region of the balloon 1 to assist the hypo
tube in staying with the balloon as it inflates and deflates.
[0023] Catheter shafts to which the balloon and laser cut hypo tube
are attached can have diameters ranging from 2.5 F to 8 F, and the
distal end may be tapered and slightly less in diameter than the
proximal end.
[0024] In FIG. 6, the dimensions of the laser cut hypo tube are for
use with a 3 mm (0.118 in) diameter by 20 mm length balloon. The
circumference of a 3 mm balloon is .PI.D=3.14(3 mm)=9.42 mm or 0.37
in. As can be readily appreciated, the total length of all U-shaped
connectors 7 (up and back) must be greater than the circumference
of the inflated balloon 1. The length of each U-shaped connector 7
(up and back), may be calculated using the following equation: 1
.PI. d n ,
[0025] where d is the diameter of the inflated balloon and n is the
number of struts. The total length of the U-shaped bends (up and
back) must exceed this length.
[0026] The resulting number is divided by 2 to get the length which
each up-and-back side of the U-shaped connector should exceed. For
example: for a 3 mm balloon compatible, laser-cut hypo tube with
four struts, the length of each U-shaped connector (up and back) is
0.37 inch divided by 4=0.0925 in. Further divide by 2 and to get
0.04625 in. This is the length that each side of the U-shaped
connector must exceed.
[0027] There is also one or more sets of U-shaped connectors 7 in
between the sinusoidal bends 6. The set includes one U-shaped
connector for each strut (3 struts--a set of 3 U-shaped connectors;
4 struts--a set of 4 U-shaped connector; and so on). The number of
U-shaped connector sets depends on the length of the balloon and
thus, the length of the laser cut hypo tube. For a 20 mm length
balloon, there is one set of U-shaped connectors spaced 10 mm from
the end (at the halfway point along length of balloon). For a 40 mm
length balloon, there are three sets of U-shaped connectors spaced
in 10 mm increments (the first set is spaced 10 mm from one end;
the second set is spaced 10 mm from first set; and the third set is
spaced 10 mm from each the second set and the other end). The
equation for number of sets of U-shaped connectors. 2 L 10 - 1
,
[0028] where L=length of balloon in mm. Other embodiments, such as
those shown in FIGS. 7 and 8, do not incorporate the intermediate
U-shaped connectors.
[0029] FIG. 12 is directed to another embodiment of a
non-deployable stent 102 which can be used with a conventional
balloon catheter, in accordance with the present invention. The
stent of this embodiment preferably has a Nitinol structure, though
other materials can be used as discussed supra, that incorporates
bends for both radial and longitudinal expansion of the stent in
response to radial and longitudinal expansion of the balloon during
inflation, so that the stent 102 maintains the balloon in its
intended position. Similar to the stents of the other embodiments
of the present invention discussed supra, the stent comprises a
laser cut hypo tube that expands upon inflation of the balloon and
collapses upon deflation of the balloon. Further, the stent is
preferably secured to the balloon with some type of anchoring
means. Preferably, such anchoring means are utilized at the ends of
the stent and around the neck of the balloon. Examples of such
anchoring means include an adhesive such as for example a UV
adhesive, cyanoacrylate, or a two-part epoxy, RF heat welding,
solvent bonding, or crimping or swaging the ends of the stent to
the shaft. Alternatively, a mechanical anchoring means can be used
to anchor the stent to the balloon. With such a means, a small
sleeve made of a similar material as the shaft of the catheter is
mounted over the ends of the stent and heat welded together where
the ends of the stent are sandwiched between the shaft and the
sleeve.
[0030] FIG. 12 shows the hypo tube of the stent in an unrolled
(flat) and non-extended state. The stent 102 has a proximal end 103
and a distal end 104. At each end, there are cage mounted flanges
110. These flanges can be used to attach the stent to the neck of
the balloon. The flanges also spring open radially to permit
insertion of the balloon during assembly. Between the ends, the
stent 102 includes extension sections 112, serpentine rings 114 and
elongation links 116.
[0031] Serpentine rings 114 have a serpentine shape and allow the
stent 102 to expand radially when a balloon in the stent is
inflated. However, as the balloon expands, the serpentine rings 114
will shorten in length. Accordingly, extension sections 112 and
elongation links 116 expand longitudinally to compensate for any
shortening of the length of serpentine rings 114. Preferably,
elongation links 116 have a z-shape or accordion shape, as shown in
FIG. 12.
[0032] FIG. 13 is an alternative embodiment showing a stent 202
having the same features as the stent in FIG. 12 except that stent
202 in FIG. 13 has elongated links 216 with a different pattern
than the elongated links 116 in stent 102 of FIG. 12. More
specifically, elongated links 216 have a zig zag pattern. Stent 202
of FIG. 13 operates in a substantially similar manner to that of
stent 102 in FIG. 12.
[0033] While the present invention is not limited in the number of
serpentine rings, extension sections and elongated links used in
the stent, FIG. 13 illustrates a preferred embodiment. The stent
202 in FIG. 13 has from proximal end 103 to distal end 104, a first
extension section 112, a first set of serpentine rings 114, a first
set of elongated links 216, a second set of serpentine rings 114, a
second set of elongated links 216, a third set of serpentine rings
114, a third set of elongated links 216, a fourth set of serpentine
rings 114, and a second extension section 112.
[0034] FIG. 13 also shows an example of possible dimensions, in
inches, of each of the components of the stent 202. These
dimensions would also be used for each of the similar components in
stent 102 in FIG. 12.
[0035] It will be understood that the embodiments and examples of
the present invention, which have been described, are illustrative
of some of the applications of the principles of the present
invention. Numerous modifications may be made by those skilled in
the art without departing from the true spirit and scope of the
invention.
* * * * *