U.S. patent application number 10/337703 was filed with the patent office on 2003-05-29 for angioplasty catheter system with adjustable balloon length.
Invention is credited to Bavaro, Vincent, Lee, Jeong S., Lim, Florencia, Stiger, Cheryl, Voyles, Carolyn.
Application Number | 20030100916 10/337703 |
Document ID | / |
Family ID | 23865735 |
Filed Date | 2003-05-29 |
United States Patent
Application |
20030100916 |
Kind Code |
A1 |
Lee, Jeong S. ; et
al. |
May 29, 2003 |
Angioplasty catheter system with adjustable balloon length
Abstract
A resizable inflatable balloon, primarily for use with balloon
catheters. The resizable inflatable balloon comprises a first
portion and an adjacent second portion. The first portion is
inflatable to a working diameter at a first pressure while the
second portion does not substantially expand at the first pressure.
The second portion does expand to the working diameter at a second
pressure greater than the first pressure, so that subsequent
inflation at the first pressure inflates the first portion and the
second portion to the working diameter. The methods of resizing the
inflatable members include placing the inflatable balloon in a mold
and supplying inflation fluid to expand the second member to the
working diameter. In practice, a catheter having the resizable
inflatable balloon is guided through a patient's vasculature until
the inflatable balloon is positioned in a desired region. Inflation
fluid is supplied at the first pressure to inflate the first
portion to the working diameter. The catheter is withdraw and the
inflatable balloon is resized as described above. The catheter is
reintroduced to the patient's vasculature and inflation fluid is
then supplied at the first pressure to inflate both the first and
second portions.
Inventors: |
Lee, Jeong S.; (Diamond Bar,
CA) ; Lim, Florencia; (Union City, CA) ;
Stiger, Cheryl; (San Diego, CA) ; Voyles,
Carolyn; (Escondido, CA) ; Bavaro, Vincent;
(Temecula, CA) |
Correspondence
Address: |
FULWIDER PATTON LEE & UTECHT, LLP
HOWARD HUGHES CENTER
6060 CENTER DRIVE
TENTH FLOOR
LOS ANGELES
CA
90045
US
|
Family ID: |
23865735 |
Appl. No.: |
10/337703 |
Filed: |
January 6, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10337703 |
Jan 6, 2003 |
|
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|
09469966 |
Dec 21, 1999 |
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6527741 |
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Current U.S.
Class: |
606/194 |
Current CPC
Class: |
B29K 2105/258 20130101;
B29L 2031/7542 20130101; B29C 43/10 20130101; B29L 2022/025
20130101; B29C 55/28 20130101; A61M 2025/1031 20130101; A61M
2025/1059 20130101; B29C 43/36 20130101; A61M 25/1027 20130101;
B29C 49/00 20130101 |
Class at
Publication: |
606/194 |
International
Class: |
A61M 029/00 |
Claims
What is claimed is:
1. A resizable inflatable balloon, comprising: a) a first portion
having at least a length that is expandable to a working diameter
at a first pressure; and b) a second portion longitudinally
adjacent the first portion that is not substantially expandable at
the first pressure and is expandable to the working diameter at a
second pressure greater than the first pressure, so that subsequent
inflation at the first pressure expands the first portion and the
second portion to the working diameter.
2. The resizable inflatable balloon of claim 1 wherein the first
pressure is about 14 to about 16 atmospheres.
3. The resizable inflatable balloon of claim 2 wherein the second
pressure is about 18 to about 30 atmospheres.
4. The resizable inflatable balloon of claim 1 wherein the
resizable inflatable balloon is formed from a polymeric material
having a Shore durometer hardness of about 60D to about 85D.
5. The resizable inflatable balloon of claim 1 wherein the
resizable inflatable balloon is formed from a thermoplastic
polyurethane.
6. The resizable inflatable balloon of claim 5 wherein the
thermoplastic polyurethane is a polyurethane block copolymer having
a Shore durometer hardness of about 65D to about 75D.
7. The resizable inflatable balloon of claim 1 wherein the
resizable inflatable balloon is formed from a thermoplastic
elastomeric polyester.
8. The resizable inflatable balloon of claim 7 wherein the
thermoplastic elastomeric polyester is a copolyester having a Shore
durometer hardness of about 63D to about 82D.
9. The resizable inflatable balloon of claim 1 wherein the
resizable inflatable balloon is formed from a thermoplastic
elastomeric block copolymer.
10. The resizable inflatable balloon of claim 9 wherein the
thermoplastic elastomeric block copolymer is a polyether block
amide copolymer having a Shore durometer hardness of about 63 to
about 72D.
11. The resizable inflatable balloon of claim 1 wherein the first
portion is from about 10 to about 50 millimeters long.
12. The resizable inflatable balloon of claim 1 wherein the first
portion has a length of about 10 to about 30 millimeters.
13. The resizable inflatable balloon of claim 1 wherein the second
portion has a length of about 10 to about 50 millimeters.
14. The resizable inflatable balloon of claim 1 wherein the second
portion has a length of about 20 to about 40 millimeters.
15. The resizable inflatable balloon of claim 11 wherein the
working diameter is about 1.5 to about 4.0 millimeters.
16. The resizable inflatable balloon of claim 1 wherein the second
portion has a greater wall thickness than the first portion prior
to expansion of the second portion at the second pressure.
17. The resizable inflatable balloon of claim 1 having a third
portion between the first portion and the second portion that is
not substantially expandable at the first pressure or at the second
pressure.
18. A balloon catheter, comprising a) a catheter shaft having an
outer tubular member having proximal and distal ends and an lumen
extending therein, and an inner tubular member disposed within the
lumen of the outer tubular member and having proximal and distal
ends and a lumen extending therein; and b) a resizable balloon on a
distal section of the catheter shaft, comprising a first portion
expandable to a working diameter at a first pressure, and a second
portion longitudinally adjacent to the first portion that is not
substantially expandable at the first pressure and is expandable to
the working diameter at a second pressure greater than the first
pressure, so that subsequent inflation at the first pressure
expands the first portion and the second portion to the working
diameter.
19. The balloon catheter of claim 18 wherein the first portion of
the balloon is distal to the second portion of the balloon.
20. The balloon catheter of claim 18 wherein the first portion of
the balloon is proximal to the second portion of the balloon.
21. The balloon catheter of claim 19 wherein the balloon has a
distal end secured to the inner tubular member and a proximal end
secured to the outer tubular member at a location proximal to the
distal end of the outer tubular member.
22. The balloon catheter of claim 21 wherein the distal end of the
outer tubular member extends distally within the balloon to a
distal end of the second portion.
23. A kit for resizing inflatable tubular member comprising a
catheter having: a) a resizable inflatable tubular member with a
first portion that is expandable to a working diameter at a first
pressure and a second portion longitudinally adjacent the first
portion that is not substantially expandable at the first pressure
and is expandable to the working diameter at a second pressure
greater than the first pressure, so that subsequent inflation at
the first pressure expands the first portion and the second portion
to the working diameter; and b) a mold having a cavity having a
diameter which is approximately the working diameter, and having a
length which is longer than the first portion.
24. The kit of claim 23 further comprising at least one additional
mold, each mold having a cavity with a different length.
25. A method for resizing an inflatable tubular member, comprising:
a) positioning within a cavity of a first mold a resizable
inflatable tubular member having a first portion with a length and
a working diameter at a first pressure, and having a second portion
longitudinally adjacent the first portion which is not
substantially expandable at the first pressure and which is
expandable at a second pressure greater than the first pressure,
the cavity of the first mold having a length which is greater than
the length of the first portion; and b) supplying inflation fluid
at the second pressure to expand at least a section of the second
portion of the inflatable tubular member within the first mold.
26. The method of claim 25 including: a) positioning the inflatable
tubular member within a second mold having a cavity with a second
length which is longer than the length of the cavity of the first
mold; and b) supplying inflation fluid at the second pressure to
expand at least a section of the second portion of the inflatable
tubular member within the second mold.
27. A method for performing a medical procedure, comprising: a)
advancing through a patient's vasculature an elongated catheter
having a resizable inflatable tubular member with a first portion
that is inflatable to a first working diameter at a first pressure
and a second portion longitudinally adjacent the first portion that
is not substantially expandable at the first pressure and is
expandable at a second pressure greater than the first pressure; b)
supplying inflation fluid at the first pressure to expand the first
portion to the working diameter; c) withdrawing the catheter from
the patient's vasculature; d) positioning the inflatable tubular
member within a mold having a cavity with a length which is longer
than the first portion; e) supplying inflation fluid at the second
pressure to expand the second portion of the inflatable tubular
member within the mold; f) advancing the catheter through the
patient's vasculature until the inflatable tubular member is
disposed within a desired region thereof; and g) supplying
inflation fluid at the first pressure to expand the first portion
and the second portion.
28. The method of claim 27 wherein the cavity of the mold has a
diameter which is at least the first working diameter of the first
portion, and wherein step (g) comprises expanding the first portion
and the second portion to at least the first working diameter of
the first portion.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention is directed to intraluminal devices
for stent deployment, percutaneous transluminal coronary
angioplasty (PTCA), and the similar procedures that are facilitated
by an inflatable tubular member.
[0002] PTCA is a widely used procedure for the treatment of
coronary heart disease. In this procedure, a balloon dilatation
catheter is advanced into the patient's coronary artery and the
balloon on the catheter is inflated within the stenotic region of
the patient's artery to open up the arterial passageway and
increase the blood flow through the artery. To facilitate the
advancement of the dilatation catheter into the patient's coronary
artery, a guiding catheter having a preshaped distal tip is first
percutaneously introduced into the cardiovascular system of a
patient by the Seldinger technique through the brachial or femoral
arteries. The catheter is advanced therein until the preshaped
distal tip of the guiding catheter is disposed within the aorta
adjacent the ostium of the desired coronary artery. A balloon
dilatation catheter may then be advanced through the guiding
catheter into the patient's coronary artery until the balloon on
the catheter is disposed within the stenotic region of the
patient's artery. Once properly positioned across the stenosis, the
balloon is inflated one or more times to a predetermined size with
radiopaque liquid at relatively high pressures, e.g., generally
4-12 atmospheres (atm), to dilate the stenosed region of a diseased
artery. After the inflations, the balloon is finally deflated so
that the dilatation catheter can be removed from the dilatated
stenosis to resume blood flow.
[0003] Similarly, balloon catheters may be used to deploy
endoprosthetic devices such as stents. Stents are generally
cylindrically shaped intravascular devices that are placed within a
damaged artery to hold it open. The device can be used to prevent
restenosis and to maintain the patency of blood vessel immediately
after intravascular treatments. Typically, a compressed or
otherwise small diameter stent is disposed about an expandable
member such as a balloon on the distal end of a catheter, and the
catheter and stent thereon are advanced through the patient's
vascular system. Inflation of the balloon expands the stent within
the blood vessel. Subsequent deflation of the balloon allows the
catheter to be withdrawn, leaving the expanded stent within the
blood vessel.
[0004] One difficulty associated with the use of balloon catheters
is the necessity of stocking a wide range of catheters having
balloon sizes that range in length as well as diameter. A typical
catheter lab stocks catheters with balloon lengths of 15 mm, 20 mm,
30 mm and 40 mm, for example, in a range of diameters such as 1.5
mm to 4.0 mm in 0.25 mm increments. When procedures require
different length balloons, different conventional catheters must be
used to provide the necessary variety of working lengths. For
example, an angioplasty procedure may require the use of two or
more stents of different lengths, thus necessitating the use of two
of more catheters having balloons of different working lengths to
deploy different length stents.
[0005] What has been needed is a balloon catheter capable of
performing a procedure at a variety of working lengths, which
avoids the necessity of using multiple catheters. This invention
meets these and other needs.
SUMMARY OF THE INVENTION
[0006] This invention is directed to a resizable inflatable
balloon, having a first dimension that may be resized to a second
larger dimension. The balloon generally comprises a first portion
having at least a section thereof expandable to a working diameter
at a first pressure, and a second portion longitudinally adjacent
to the inflatable portion that is not substantially expandable at
the first pressure and is expandable to the working diameter at a
second pressure greater than the first pressure. To lengthen the
balloon working length beyond the length of the first portion, the
balloon is resized at the second pressure. Thus, following
expansion of the second portion at the second pressure, subsequent
inflation of the balloon at the first pressure expands the first
portion and the second portion to the working diameter, so that the
balloon is thereby resized to the longer working length formed by
both the first and second portions being inflated. The second
portion may be either proximally or distally adjacent to the first
portion.
[0007] In a preferred embodiment, the first pressure comprises a
working pressure for an angioplasty-type balloon, such as about 10
to about 16, preferably about 14 to about 16 atm, while the second
pressure comprises a relatively high pressure, such as about 18 to
about 30 atm. The presently preferred materials for the first
portion and second portion are polymeric materials that are
sufficiently stiff to resist expansion at the first pressure prior
to being blown into a balloon, but are not so stiff as to be
unexpandable at the second pressure. In one embodiment, the balloon
material can be expanded at room temperature to resize the balloon
at the second pressure, so that the balloon does not have to be
heated during resizing. A variety of polymeric materials used for
catheter balloons may be used including polyamides, polyurethanes,
and polyesters, provided they have the required expansion
characteristics discussed herein. Presently preferred materials
include polyurethane block copolymers such as TECOTHANE,
copolyesters such as HYTREL, and polyether block amides such as
PEBAX. The polyesters such as polyethyleneterephthalate (PET),
polyethylene naphthalate (PEN), and polyamides such as nylons which
require high pressures greater than about 30 atm to expand at room
temperature to form the resized balloon are generally not
preferred. However, these materials may be used if the second
pressure is greater than about 30 atm or if the materials are
processed so as to resize at pressures less than about 30 atm.
[0008] The invention also comprises methods for resizing inflatable
balloons, including the steps of providing an inflatable balloon
comprising a first portion that is expandable to a working diameter
at a first pressure, and a second portion adjacent the first
portion that is not substantially expandable at the first pressure;
placing the inflatable balloon inside a mold; supplying inflation
fluid at a second pressure that is greater than the first pressure
to expand the second portion to the same working diameter or
another (second) working diameter so that subsequent inflation to
at least the first pressure expands the first portion and the
second portion to the same or the second working diameter. The
second working diameter is less than, equal to, or greater than the
first working diameter formed at the first pressure, and in a
preferred embodiment it is equal or greater than the first
diameter. Further, this invention comprises methods for using
intraluminal devices having a resizable balloon that typically
include the steps of providing an elongated intraluminal device
having a resizable balloon adjacent the distal end; guiding the
elongated intraluminal device through a patient's vasculature until
the resizable balloon is disposed within a desired region of the
patient's vasculature; supplying inflation fluid at the first
pressure to inflate the first portion to the working diameter;
withdrawing the elongated intraluminal device; placing the
resizable balloon within a mold; supplying inflation fluid at the
second pressure to expand the second portion to the same or another
working diameter; guiding the elongated intraluminal device through
the patient's vasculature until the resized balloon is disposed
within a desired region of the patient's vasculature; and supplying
inflation fluid at the first pressure to expand the first portion
and the second portion to the same or the other working diameter.
In a presently preferred embodiment, the balloon of the invention
is resizable at room temperature, so that the second portion does
not require heating before it can be expanded to the working
diameter at the second pressure.
[0009] This invention provides an inflatable tubular member that is
resizable to a variety of working dimensions, so that the desired
working dimension for a given procedure or anatomy is readily
available. As a result, the catheter of the invention can be safely
resized and reduces the number of catheters that must be stocked by
catheter laboratories. Other advantages of the invention will
become more apparent from the following detailed description of the
invention when taken in conjunction with the accompanying exemplary
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is an elevational view, partially in section, of a
dilatation catheter embodying features of the invention prior to
resizing.
[0011] FIG. 2 is an enlarged view of the proximal end of the
balloon of the catheter of FIG. 1.
[0012] FIG. 3 is a transverse cross-sectional view of the catheter
shown in FIG. 1 taken along the lines 3-3.
[0013] FIG. 4 is another transverse cross-sectional view of the
catheter shown in FIG. 1 taken along the lines 4-4.
[0014] FIG. 5 is yet another transverse cross-sectional view of the
catheter shown in FIG. 1 taken along the lines 5-5.
[0015] FIG. 6 is a schematic view of a balloon mold useful in the
practice of this invention.
[0016] FIG. 7 is another schematic view of the balloon mold shown
in FIG. 6, with a balloon catheter embodying features of the
invention prior to resizing.
[0017] FIG. 8 is an elevational view, partially in section, of the
dilatation catheter shown in FIG. 1 with a balloon after
resizing.
DETAILED DESCRIPTION OF THE INVENTION
[0018] FIG. 1 illustrates a dilatation catheter 10 embodying
features of the invention. The catheter 10 comprises a catheter
shaft 12, and inflatable balloon 14 on a distal portion 15 of the
catheter shaft and an adapter 16 on a proximal end 17 of the
catheter shaft. In the embodiment illustrated in FIG. 1, the
catheter shaft 12 has an inner tubular member 18 and outer tubular
member 20 disposed concentrically about the inner tubular member to
define an annular inflation lumen 22. The inner tubular member 18
has an inner lumen 24 which is adapted to slidably receive a
guidewire 26.
[0019] Inflatable balloon 14 comprises a first portion 28 which is
expandable to its working diameter when inflation fluid is
introduced through annular inflation lumen 22 at a first pressure.
Preferably, the first pressure comprises a procedural pressure,
such as conventional working pressures for angioplasty-type balloon
catheters, ranging from about 14 to about 16 atm. Inflatable
tubular member 14 also comprises a second portion 30 that has a
nominal unexpanded outer diameter similar to outer tubular member
20. Second portion 30 is configured so that it initially does not
expand substantially when inflation fluid is introduced into
annular inflation lumen 22 at the first pressure. The terminology
"not substantially expandable" should be understood to mean that
the second portion does not expand to the working diameter or to a
diameter approaching the working diameter at the first pressure
prior to being inflated at the second pressure. However, as shown
in FIG. 1 (in phantom) and FIG. 8, second portion 30 is expandable
to a working diameter, which in the embodiment illustrated in FIG.
1 is the working diameter of the first portion 28, upon
introduction of inflation fluid into annular inflation lumen 22 at
a second pressure, greater than the first pressure. The second
pressure comprises a pressure above the procedural pressure. The
second pressure is preferably obtainable using conventional and
readily available in/deflators such as the 20/30 from ACS, and is
preferably about 18 to about 30 atm.
[0020] In the embodiment illustrated in FIG. 1, the first portion
is distal to the second portion. However, a variety of suitable
configurations may be used which vary the location of the first and
second portions relative to one another. For example, in alternate
embodiments, it may be desirable to configure inflatable balloon 14
so that the second portion 30 is located distally to the first
portion 28, and an unexpanded portion may be located between the
first and second portions so that the second portion 30 is
longitudinally spaced from the first portion 28 (not shown).
Additionally, in the embodiment illustrated in FIG. 1, the distal
end 21 of the outer tubular member 20 is located at the proximal
end 31 of the first portion 28 and at the distal end 32 of the
second portion 30. This configuration provides a catheter with
optimized performance prior to resizing of the balloon, while still
allowing for resizing the balloon by expansion of the second
portion of the balloon. However, in alternative embodiments, the
outer tubular member distal end 21 may be located proximally of the
distal end 32 of the second portion 30. In the embodiment
illustrated in FIG. 1, second portion 30 is configured to conform
closely to, and is coaxially disposed over, outer tubular member 20
prior to expansion. Second portion 30 is not attached to outer
tubular member 20 except at balloon seal 33, which is located at
the proximal end of the balloon 14, to allow expansion of the
second portion distal to the seal. Accordingly, any desired length
of second portion 30 up to the balloon seal 33 may be expanded
during and after resizing.
[0021] In a presently preferred embodiment, inflatable balloon 14
is formed from a polymeric material that is sufficiently stiff so
that the second portion 30 resists axial expansion at the first
pressure, yet is sufficiently soft and expandable so that the
second portion 30 may be expanded when inflated to the second
pressure at room temperature. The polymer's durometer provides a
useful guide for selecting suitable materials. Currently preferred
embodiments comprise polymers having a Shore durometer hardness
from about 65D to about 85D, preferably from about 70D to about
82D. In a presently preferred embodiment, the polymeric material is
formed from polyurethanes having sufficient stiffness to allow a
relatively high first pressure, of about 14 atm or more, while
requiring a substantially greater second pressure of at least about
18 atm to minimize the chance of inadvertent expansion of the
second portion at the first pressure. However, the presently
preferred materials have a sufficiently low second pressure of not
greater than about 30 atm, to be readily resizable by inflation at
the second pressure. Specifically preferred thermoplastic
polyurethanes include, polyurethane block copolymers such as
TECOTHANE 65D and 75D. Other suitable polymers include
thermoplastic elastomeric polyester polymers, such as copolyesters
such as HYTREL 63D, 72D, and 82D, and polyamides including
thermoplastic elastomeric polyether block amide copolymers such as
PEBAX 63D-72D, preferably PEBAX 63D. Blends of different polymers
or of different Shore durometer grades of a polymer may also be
used. Although the Shore durometers suggest suitable materials,
polymers having other characteristics may also be useful, provided
they have the sufficient stiffness at the first pressure while
being expandable at the second pressure. However, in an alternative
embodiment, a releasable restraining member such as adhesive, outer
bands or straps, or a thin polymeric sleeve is provided at the
second portion of the balloon so that the second portion resists
axial expansion at the first pressure. The restraining member is
configured to be releasable before or during inflation within the
mold at the second pressure, so that the second portion 30 of the
balloon 14 expands to the working diameter at the second
pressure.
[0022] The specifications of inflatable balloon 14 may be varied as
necessary for the intended application. For use in the coronary
vasculature, the working diameter of inflatable balloon 14 is
typically about 1.5 to about 4.0 mm, while suitable lengths of the
inflatable balloon 14 are typically about 10 to about 60 mm. One of
skill in the art may easily adjust the dimensions to adapt the
invention to other applications. For example, an inflatable balloon
configured for prostatic urethral dilatations should have a working
diameter of about 10 to about 30 mm. To allow the inflatable
balloon 14 to be resized to a range of working lengths, the first
portion 28 is configured to have a length at the low end of the
range. The length of the first portion 28 is about 10 to about 50
mm, preferably about 10 to about 30 mm. Likewise, the unattached
portion of the second portion 30 distal to balloon seal 33 has
sufficient length to allow inflatable tubular member 14 to be
resized to a range of working lengths, such as about 10 to about 50
mm, preferably about 20 to about 40 mm. For example, first portion
28 may have a length of about 10 mm while the unattached portion of
second portion 30 may have a length of about 30 mm. Such an
embodiment would provide an inflatable balloon 14 of about 10 mm
that is resizable to up to about 40 mm.
[0023] To the extent not previously described herein, the various
catheter components may be formed of conventional materials. The
inflatable balloon 14 is formed using conventional methods such as
extrusion and blowing inside a mold, but, as discussed above, with
a longer shaft length than conventional balloons. During the
initial balloon blowing inside a mold, the first portion 28 of the
balloon 14 expands and the second portion 30 of the balloon 14 is
not expanded. In a presently preferred embodiment, the unexpanded
second portion 30 has a greater wall thickness than the wall
thickness of the expanded first portion 28 blown into the balloon,
until the second portion 30 of the balloon is expanded at the
second pressure. Typically, the unexpanded second portion 30 has a
wall thickness of about 0.005 inch (0.13 mm) to about 0.008 inch
(0.20 mm), and the expanded first portion 28 has a wall thickness
of about 0.0005 inch (0.013 mm) to about 0.001 inch (0.025 mm). The
inflatable balloon 14 is then attached proximally to the outer
tubular member 20 and distally to the inner tubular member 18.
Alternatively, the inflatable balloon 14 may be formed integrally
with the outer tubular member 20 as a one piece unit.
[0024] The invention also comprises methods of using a catheter 10
having an inflatable balloon 14. In reference to FIGS. 6 and 7, a
method of resizing the inflatable balloon 14 generally comprises
positioning the inflatable balloon 14 in a mold 34 having a cavity
36 configured to allow expansion of second portion 30 to the
working diameter along a desired length adjacent to first portion
28. Once inflatable balloon 14 is suitably positioned, inflation
fluid is introduced into annular inflation lumen 22 at the second
pressure. This causes second portion 30 to expand from the nominal
diameter shown in FIG. 6 to the working diameter shown in FIG. 7.
The use of mold 34 prevents second portion 30 from expanding to a
diameter larger than the desired working diameter. Further, by
using molds having different sized cavities, some or all of second
portion 30 may be expanded to provide an inflatable balloon 14
having the desired working length, and the second portion 30 may be
expanded to a variety of different diameters less than, equal to,
or greater than the working diameter of the first portion at the
first pressure.
[0025] Furthermore, the methods of resizing the inflatable balloon
14 may be incorporated into a medical procedure wherein catheter 10
is guided through a patient's vasculature until inflatable balloon
14 is disposed within a desired region of the vasculature. A
radiopaque band may be provide to aid fluoroscopic visualization of
the inflatable balloon's position. Inflation fluid is introduced
into annular inflation lumen 22 at a first pressure so that first
portion 28 inflates to its working diameter but second portion 30
does not substantially expand. Catheter 10 is withdrawn from the
patient and inflatable balloon 14 is positioned within mold 34 as
described above. Introduction of inflation fluid into annular
inflation lumen 22 at the second pressure expands some or all of
the second portion 30 to the working diameter, depending upon the
size of the mold's cavity 36. The catheter 10 is then reinserted
into the patient's vasculature and guided so that inflatable
balloon 14 is positioned within a desired region of the
vasculature. Inflation fluid then may be introduced into annular
inflation lumen 22 at the first pressure to inflate first portion
28 and the expanded second portion 30 to the working diameter.
Preferably, these procedures are used to deploy stents or to
perform angioplasty or other procedures that are facilitated by an
inflatable tubular member. According to these methods, the
resizable inflatable balloons of the invention reduce the number of
catheters that must be stocked to perform medical procedures.
[0026] A variety of modifications and improvements can be made to
the present invention without departing from the scope thereof. For
example, while a coaxial inner and outer membered catheter shaft is
illustrated in FIG. 1, a variety of suitable catheter
configurations may be used with the balloon of the invention,
including dual lumen shafts, rapid exchange type catheters, and the
like.
* * * * *