U.S. patent application number 15/799184 was filed with the patent office on 2018-03-29 for stiffened balloon apparatus.
The applicant listed for this patent is Jeffrey Grayzel, Joseph Grayzel. Invention is credited to Jeffrey Grayzel, Joseph Grayzel.
Application Number | 20180085562 15/799184 |
Document ID | / |
Family ID | 22822976 |
Filed Date | 2018-03-29 |
United States Patent
Application |
20180085562 |
Kind Code |
A1 |
Grayzel; Jeffrey ; et
al. |
March 29, 2018 |
STIFFENED BALLOON APPARATUS
Abstract
A stiffened balloon apparatus for use in angioplasty. Elongate
stiffening members disposed longitudinally on the expandable
balloon stiffen the membrane of said balloon. The stiffening
members possess sufficient rigidity to resist local deformation of
the wall of said expandable balloon upon expansion of said balloon
and upon contact of said stiffening member with a local deformation
within an anatomical passage or target lumen. Projections and/or
raised surfaces on a stiffening member may engage, incise, crush,
fracture, or pierce occlusions and/or the inner surface of the
passage or target lumen in which it is being operated. Associated
method for use to incise the inner surface of a target lumen or
incise the stenosis that may be located therein.
Inventors: |
Grayzel; Jeffrey;
(Morristown, NJ) ; Grayzel; Joseph; (Englewood,
NJ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Grayzel; Jeffrey
Grayzel; Joseph |
Morristown
Englewood |
NJ
NJ |
US
US |
|
|
Family ID: |
22822976 |
Appl. No.: |
15/799184 |
Filed: |
October 31, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13022503 |
Feb 7, 2011 |
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15799184 |
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11018006 |
Dec 21, 2004 |
7883537 |
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13022503 |
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09912008 |
Jul 24, 2001 |
6942680 |
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11018006 |
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60220297 |
Jul 24, 2000 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 17/320725 20130101;
A61M 2025/109 20130101; A61M 2025/1079 20130101; A61F 2/958
20130101; A61M 2025/1084 20130101; A61F 2002/9583 20130101; A61M
25/104 20130101; A61M 2025/1086 20130101; A61B 2017/22061
20130101 |
International
Class: |
A61M 25/10 20130101
A61M025/10; A61F 2/958 20130101 A61F002/958 |
Claims
1-47. (canceled)
48. A stiffened balloon apparatus for use within an anatomical
passage in the human body comprising: an expandable balloon having
at least one elongate stiffening member disposed longitudinally
along a perimeter of said balloon; wherein said balloon is made of
a flexible material; wherein said stiffening member is stiffer than
said balloon material such that said stiffening member will resist
deformation of the balloon membrane of said balloon; and wherein at
least one of the one or more stiffening members includes a
plurality of projections, said projections being outwardly disposed
in an orientation substantially perpendicular to the balloon
surface when said balloon is inflated.
49. The Stiffened balloon apparatus of claim 48 wherein the spacing
between each of said projections are of equal length.
50. The stiffened balloon apparatus of claim 48 wherein each of
said plurality of projections possesses an outermost edge oriented
longitudinally.
51. The stiffened balloon apparatus of claim 48 wherein the outer
surface of at least one of said projections is pointed.
52. The stiffened balloon apparatus of claim 48 wherein outermost
contour of at least one of said projections is rounded.
53. The Stiffened balloon apparatus of claim 48 wherein said
projections have an outward-most surface that is curvilinear in a
plane perpendicular to said balloon surface.
54. The stiffened balloon apparatus of claim 48 wherein said
plurality of projections have an outer edge surface that is
curvilinear and oriented longitudinally.
55. The stiffened balloon apparatus of claim 48 wherein said
plurality of projections form a cutting edge along the outermost
surface of said stiffening member.
56. The stiffened balloon apparatus of claim 48 wherein each of
said projections possesses a cutting edge oriented longitudinally
with respect to the longitudinal axis of said balloon.
57. The stiffened balloon apparatus of claim 48 wherein said
plurality of projections form an array of incising elements.
58. The stiffened balloon apparatus of claim 48 wherein said
plurality of projections form a saw-tooth edge on the outer surface
of said stiffening member.
59. The stiffened balloon apparatus of claim 48 wherein said
plurality of projections form a serrated structure on the outer
surface of said stiffening member.
60. The stiffened balloon apparatus of claim 48 wherein said
plurality of projections form a serrated pattern to allow said
stiffening member to incise an inner surface of an anatomical
lumen.
61. The stiffened balloon apparatus of claim 48 further comprising
a plurality of stiffening members; wherein each of said plurality
of stiffening members comprises a plurality of projections that are
uniformly spaced along the length of each of said stiffening
members in a serrated pattern; wherein each of said projections has
an outermost surface that is curvilinear and oriented
longitudinally with respect to the longitudinal axis of said
balloon.
62. A stiffened balloon apparatus for use within an anatomical
passage in the human body comprising: an expandable balloon having
at least one elongate stiffening member disposed longitudinally
along a perimeter of said balloon; wherein said balloon is made of
a flexible material; wherein said stiffening member is stiffer than
said balloon material such that said stiffening member will resist
deformation of the balloon membrane of said balloon; and wherein at
least one of the one or more stiffening members includes a raised
surface, said raised surface being outwardly disposed in an
orientation substantially perpendicular to the balloon surface when
said balloon is inflated.
63. The stiffened balloon apparatus of claim 62 wherein said raised
surface comprises an edge on its outermost surface configured to
incise the inside surface of a target lumen upon expansion of said
stiffened balloon.
64. The stiffened balloon apparatus of claim 62 wherein said raised
surfaces are sufficiently sharp to pierce an occlusion.
65. The stiffened balloon apparatus of claim 62 wherein at least
one of said one or more stiffening members comprises a plurality of
raised surfaces.
66. The stiffened balloon apparatus of claim 65 wherein each of
said raised surfaces comprises a rounded edge on its outermost
surface oriented longitudinally and configured to incise the inside
surface of a target lumen upon expansion of said stiffened
balloon.
67. A method of incising the inner surface of a target lumen within
an anatomical passage in the human body, comprising the steps of:
(1) Introducing into an anatomical passage a stiffened balloon
apparatus for use within an anatomical passage in the human body,
said stiffened balloon apparatus comprising: an expandable balloon
having at least one elongate stiffening member disposed
longitudinally along a perimeter of said balloon; wherein said
balloon is made of a flexible material; wherein said stiffening
member is stiffer than said balloon material such that said
stiffening member will resist deformation of the balloon membrane
of said balloon; and wherein at least one of the one or more
stiffening members includes a plurality of projections, said
projections being outwardly disposed in an orientation
substantially perpendicular to the balloon surface when said
stiffened balloon is inflated; (2) Navigating said stiffened
balloon apparatus through said anatomical passage to enter said
target lumen; (3) Upon entering said target lumen, inflating said
balloon so that it expands radially, such that said stiffening
members contact said inner surface of said target lumen and such
that said projections engage said inner surface of said target
lumen to incise said inner surface of said target lumen.
68. The method of claim 67 further comprising the step of
maneuvering said stiffened balloon apparatus to further incise said
inner surface of said target lumen.
69. The method of claim 67 further comprising the steps of: (4)
deflating said balloon; (5) moving said stiffened balloon apparatus
to a different target location; and (6) re-inflating said balloon
so that it expands radially, such that said stiffening members
contact the inner surface of said different target location and
such that said projections engage said inner surface of said
different target location to incise said inner surface of said
different target location.
Description
[0001] This application is a continuation of patent application No.
13/022,503 (pending), which claims benefit of U.S. patent
application Ser. No. 11/018,006 (now U.S. Pat. No. 7,833,537),
which claims benefit of U.S. patent application Ser. No. 09/912,008
(now U.S. Pat. No. 6,942,680), which claims the benefit of U.S.
Provisional Application No. 60/220,297, filed Jul. 24, 2000. All of
these applications are hereby incorporated herein by reference in
their entirety.
FIELD OF THE INVENTION
[0002] The invention relates to the field of balloon catheters for
angioplasty and the delivery of stents and stent-grafts.
BACKGROUND OF THE INVENTION
[0003] Inflatable balloons are employed to dilate stenotic arteries
in angioplasty, i.e., percutaneous transluminal coronary
angioplasty (PTCA), to dilate stenotic cardiac valves in
valvuloplasty, and to deliver and reconfigure stents and
stent-grafts. To prevent late lumen loss and restenosis, a stent is
carried on a balloon, positioned and expanded to remain in a
dilated vessel. Unfortunately, currently available balloon systems
for angioplasty and for delivery and expansion of stents often fail
to properly deploy the stent to produce a uniform diameter and
cross-sectional area along the length of the stent. This results
from the very nature of such a cylindrical balloon which is made of
a thin, flexible membrane and hence can expand radially to
different diameters along its longitudinal dimension. If an
obstructive lesion in a blood vessel is of a firmer and less
compliant tissue than the normal vascular wall, e.g., fibrous or
calcified matter, such tissue presents a much greater resistance
than the normal vascular wall to dilatation as the balloon expands.
As a balloon is expanded, such stenoses, narrowings, and
obstructions impinge upon the expanding balloon to cause an area of
relative narrowing or distortion, a so-called "waist".
Correspondingly, a stent delivered on such a balloon will suffer
from a similar distortion or "waist configuration" as it is
conformably expanded with the expanding delivery balloon.
[0004] If the stent adopts a "waist configuration", it is generally
indicative of inadequate dilatation of the stenotic lesion within
the blood vessel. The conventional approach to attempt to remedy
this inadequacy has been to increase pressure within the balloon to
expand the narrowed area. At times, a separate, higher pressure
balloon is utilized. To produce such higher pressure balloons,
flexible balloon membranes, which could rupture under increasing
internal pressure, were replaced by more rigid balloon materials
that permitted much higher internal pressures. However, the more
rigid material still has an elastic limit. Balloons made of such
material and excessively inflated will be permanently deformed, and
may eventually burst. Such deformed balloons are much more
difficult to remove from the patient. Moreover, increasing the
pressure in the balloon increases the potential for rupture and
serious harm to the patient.
[0005] Even the use of higher pressures permitted by more rigid
balloons are insufficient to dilate some arterial stenoses,
particularly if they have an annular configuration. With the stent
not completely open and the lumen not fully dilated, the final
therapeutic result is less than optimum. Some residual stenoses and
a non-uniform cross-sectional area along the length of the stent
will result.
[0006] Another problem frequently encountered during balloon
dilation of stents is the occurrence of flaring of the stent at its
ends. Stents are generally manufactured as an independent
cylindrical structure or integrated in a sleeve that is slipped
onto the balloon and adhered. Conventionally, the balloons are at
least slightly longer than the stents that they carry.
[0007] As the balloon is inflated and it expands the stent, it
typically meets less resistance at the ends of the stent and
outside the confines of the stent than it does within the stent.
Hence, at full inflation the balloon has a tendency to expand to a
slightly larger diameter beyond the ends of the cylindrical stent
than at the middle of the stent. The resulting different diameters
of expansion are transferred to the stent causing a "trumpet-like"
outward flaring of the stent at its ends, which is undesirable.
[0008] Additionally, there are several problems with the
conventional methodology for delivering a stent to an occlusive
site with a conventional balloon catheter. In trying to force the
stent inside a tight occlusion, calcified matter or other
irregularity at the occlusion often provides resistance against the
leading edge of the balloon catheter and may resist entry and
positioning of the stent. As the operator tries to advance or
withdraw the catheter, the calcified matter or other irregularity
may catch hold of the stent and capture it in place while the
catheter is moved, causing the stent to separate from the balloon.
If the stent is displaced with respect to the balloon, slips
partially off the balloon, or separates from the balloon entirely,
then the stent will not deploy properly. If the undeployed stent
separates from the balloon entirely, retrieving the undeployed
stent becomes a very serious problem. Similarly, a stent that is
only partially deployed or is incorrectly positioned presents a
very significant risk to the patient.
[0009] Where an occlusive site is only partially accessible by
means of a conventional balloon catheter, i.e., only one end of an
occlusion has an inner diameter that is of sufficient size to
receive a balloon catheter, expansion of the balloon often causes
the entire device to be squeezed and slip out of the occlusive site
entirely. Thus, attempts to open such partially accessible
occlusive sites often fail. To keep the prior art device within the
occlusive site a great deal of force may need to be applied by the
operator to prevent the device from slipping out. Such force causes
additional stress at the occlusive site and in surrounding
structures which present a further risk of rupturing the target
site or causing damage to the surrounding areas. This same behavior
is also observed in situations where an occlusion is irregular in
diameter and the expanded balloon simply slips out of the occlusive
site upon reaching a particular state of expansion.
[0010] The same difficulties are encountered in attempting to
position and deploy a stent-graft with a conventional balloon
catheter. Incomplete stent-graft deployment can result in
troublesome endoleaks caused by inadequate or otherwise ineffective
sealing of the stent-graft at the ends with the interior of the
vessel. Such endoleaks allow a channel of blood flow to develop
that bypasses the stent-graft, greatly reducing its effectiveness
and potentially causing the stent-graft to migrate. Where
stent-grafts are deployed to exclude aneurysms, such as in the
endovascular repair of an abdominal aortic aneurysm, endoleaks are
a very significant problem in that they may allow flow to an
aneurysm that could cause the aneurysm to rupture.
[0011] U.S. Pat. No. 4,796,629, by one of the present inventors,
describes a stiffened dilation balloon which addresses some of
these problems by providing an expandable balloon which exerts
greater expansion force on localized regions within the lumen. It
has been found that the uniform expansion provided by the balloon
catheter device described in U.S. Pat. No. 4,796,629 achieves
superior results in dilating occluded vessels. As such a stiffened
dilation balloon is expanded within an occlusion, the longitudinal
stiffener, acting as a rigid beam, transmits expansion force
applied to the entire length of the stiffener by the balloon to the
localized points of resistance in the vessel. Thus, as compared to
a conventional balloon, the force of dilation applied locally is
considerably increased and dilatation of highly resistant lesions
is greatly facilitated. Such a stiffened dilation balloon is
capable of achieving the same degree of dilatation as a standard
balloon delivery system but at lower pressures. The stiffeners
significantly increase the rigidity of the balloon, reducing
variations in the cross-sectional area of the balloon along its
length and reducing the occurrence of annular regions with a
narrowed waist.
[0012] Additionally, it has also been found that an inherent
limitation of the balloon catheter device described in U.S. Pat.
No. 4,796,629 is its limited maneuverability for deployment in the
vascular system. The stiffeners of such a device are fairly rigid,
have a fixed length in excess of the turning radius needed to
navigate certain pathways and have a fixed, although not
necessarily uniform, cross-section. As a result, it can be
particularly difficult to navigate the device of U.S. Pat. No.
4,796,629 through the vascular system to reach certain occlusions
in smaller vessels without utilizing non-standard entry locations
or invasive manual procedures for straightening tortuous vascular
pathways.
SUMMARY OF THE INVENTION
[0013] The present invention is directed to an improved balloon
catheter having an expandable balloon with stiffening members that
aid in uniform expansion of the balloon at a target site in a lumen
in the human body. The balloon catheter can be used in angioplasty,
endovascular, or valvuloplasty procedures, or for the delivery
and/or reconfiguration of stents or stent-grafts. The invention is
also directed to methods of dilating or expanding a lumen in the
body using a balloon catheter. Further, methods for delivering a
stent or stent-graft to a lumen in the body using the balloon
catheter are provided. In addition, methods for reconfiguring and
repositioning improperly deployed stents and stent-grafts are
disclosed. It should be understood that use of the term "balloon"
in describing the invention encompasses any balloon, chamber or
other structure which can be inflated or deflated or otherwise
expanded or reduced in size. It should also be understood that use
of the term "lumen" in describing the invention encompasses any
vessel, fluid path, valve, other flow passage or the like, or the
interior volume of any of these.
[0014] The balloon catheter of the present invention comprises a
catheter having a flow passage for pressurized fluid with an
expandable chamber, such as a balloon, connected in-between distal
and proximal catheter sections. The expandable chamber is generally
bounded by a wall suitably configured for containing a pressurized
fluid. A plurality of stiffening members are peripherally disposed
along the expandable chamber. Such stiffening members may be
embedded in the wall or connected to the inner or outer surface of
the wall. The stiffening members generally move with the wall of
the expandable chamber and are configured to resist localized
deformation in the wall of the expandable chamber.
[0015] The stiffening members may be provided with one or more
projections that culminate in either a pointed or blunt apex. The
projections may function to retain a stent or stent-graft when the
chamber is in an unexpanded state, may engage a lumen, and may
engage, incise or pierce an occlusion when the chamber is expanded.
The stiffening members and the projections may be made radio-opaque
so that the balloon or the stent may be precisely located by x-ray
imaging.
[0016] A stiffening member at the wall of the balloon may be
provided with discrete points integral with or connected to the
surface of the stiffening member. The points may be configured or
positioned to remain enveloped within pleats of the unexpanded
balloon or retained below the surface of a stent until the balloon
is expanded.
[0017] A stiffening member at the wall of the balloon may be
provided with stent retention structure integral with or connected
to the stiffening member. The stent retention structure may include
at least one projection on at least one stiffening member.
[0018] The stiffening members may be longitudinally continuous or
discontinuous, and may include many individual stiffening elements.
The stiffening elements may have a uniform shape, include elements
having different shapes, or occur as an array of discrete elements
which are adhered or otherwise attached to the expandable chamber.
The stiffening members, as well as the individual elements, may act
independently or cooperate to form one or more larger structures.
Multiple stiffening elements may co-act via one or more attaching
elements (e.g., a filament) between individual elements.
[0019] Accordingly, it is an object of the invention to further
overcome the problems and deficiencies of the prior art.
[0020] In particular, it is an object of the invention to provide
an improved stiffened balloon for dilatation and stenting, stent
retention, vessel engagement and piercing, balloon orientation and
balloon maneuverability.
[0021] It is an object of the invention to provide a stiffened
balloon with greater maneuverability than that of the prior
art.
[0022] It is another object of the invention to provide improved
stiffening members for balloons for angioplasty, valvuloplasty,
stent delivery and stent-graft delivery or reconfiguration.
[0023] It is another object of the invention to provide improved
stiffening members for balloons to engage a lumen and to engage and
fracture occlusive material within a lumen.
[0024] It is a further object of the invention to provide improved
stiffening members for balloons to retain a stent or stent-graft
for delivery to or repositioning at a target site in a lumen and
for reconfiguring a partially deployed stent or stent-graft.
[0025] It is still another object of the invention to provide a
stent delivery system for use in angioplasty procedures which
achieves full dilation of a stenosis and complete deployment of a
stent or stent-graft at the site of an obstructive lesion.
[0026] According to an aspect of the invention, a stiffened
dilating balloon includes an expandable balloon that includes a
plurality of longitudinally discontinuous stiffening members
disposed along a perimeter of the balloon; the balloon is made of a
flexible material; the stiffening members are less flexible than
the balloon; and each stiffening member affects a configuration of
an area of the perimeter of the balloon.
[0027] According to another aspect of the invention, a stiffened
balloon includes an expandable balloon that includes a plurality of
longitudinally continuous stiffening members disposed along a
perimeter of the balloon; the balloon is made of a flexible
material; the stiffening members are less flexible than the
balloon; each stiffening member affects a configuration of an area
of the perimeter of the balloon; and at least one of the stiffening
members includes a projection adapted to temporarily retain a
device at the balloon.
[0028] According to another aspect of the invention, a stiffened
balloon includes an expandable balloon including a plurality of
longitudinally continuous stiffening members disposed along a
perimeter of the balloon; the balloon is made of a flexible
material; the stiffening members are less flexible than the
balloon; each stiffening member affects a configuration of an area
of the perimeter of the balloon; and at least one of the stiffening
members includes a raised surface. The balloon wherein the raised
surface may be sufficiently sharp to pierce an occlusion.
[0029] According to a further aspect of the invention, a method of
using a stiffened balloon to dilate a lumen and deploy an
expandable device includes the steps of: introducing into a lumen a
stiffened balloon bearing an expandable device; expanding the
balloon and the device to cause at least one projection on a
stiffener of the balloon to protrude above an outer surface of the
stent and engage an inner surface of the lumen; dilating the lumen;
and deploying the device in the lumen.
[0030] According to a still further aspect of the invention, a
method of using a stiffened balloon to dilate a lumen and deploy an
expandable device includes the steps of: interdigitating at least
one projection on a stiffener of a stiffened balloon with an
expandable device; introducing into a lumen the stiffened balloon
bearing the device; expanding the balloon and the device; dilating
the lumen; and deploying the device in the lumen.
[0031] According to another aspect of the invention, a stiffened
balloon includes an expandable balloon including a plurality of
longitudinally continuous stiffening members disposed along a
perimeter of the balloon; the balloon is made of a flexible
material; the stiffening members are less flexible than the
balloon; each stiffening member affects a configuration of an area
of the perimeter of the balloon; and at least one of the stiffening
members includes a pivot point where the stiffening member may be
bent to facilitate navigation of the balloon through a passage.
[0032] According to a further aspect of the invention, a method of
reconfiguring a portion of an expandable device deployed at a lumen
includes the steps of: introducing into the lumen a stiffened
balloon bearing a longitudinal stiffener at a first location on the
balloon; aligning the longitudinal stiffener with the portion of
the expandable device; and expanding the balloon to cause the
stiffener to exert a first radial force against the portion of the
expandable device to reconfigure that portion; and the first radial
force is greater than a radial force applied by said balloon at any
other location on the balloon.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] FIG. 1 is a diagram of a closed-ended balloon with
discontinuous stiffening members;
[0034] FIG. 2 is a diagram of an open-ended balloon with continuous
longitudinal stiffening members having projections;
[0035] FIG. 3 is a diagram of a closed-ended balloon with
continuous longitudinal stiffening members having projections and a
stent positioned on the balloon;
[0036] FIG. 4 is a diagram of a stent-graft;
[0037] FIGS. 5A, 5B, 5C and 5D are diagrams showing cross-sectional
views of balloons with projections;
[0038] FIGS. 6A, 6B and 6C are diagrams showing stiffening members
with areas of increased flexibility;
[0039] FIGS. 7A-7G are diagrams showing discontinuous stiffening
members;
[0040] FIGS. 8A-8I are diagrams showing cross-sectional views of
stiffening members;
[0041] FIGS. 9A-9J are diagrams showing stiffening members;
[0042] FIGS. 10A-10G are diagrams showing projections; and
[0043] FIG. 11 is a diagram showing interconnected projections.
DETAILED DESCRIPTION OF THE INVENTION
[0044] FIG. 1 is a drawing of an embodiment of the present
invention, indicated generally as device 10, particularly suited
for navigating curved or otherwise angled passages. In
angio-valvuloplasty procedures, device 10 may be advantageously
utilized to access vessels via passages that have curved sections
and, in certain embodiments, even passages that include acute
angles. Device 10 comprises a balloon having a distal end 12, a
balloon 14, discontinuous stiffening members 16 and proximal end
18. Device 10 is generally comprised of standard inert balloon
catheter materials suitable for introduction into the human
body.
[0045] Distal end 12, balloon 14 and proximal end 18 are preferably
comprised of a thin, flexible, and generally inelastic material
that expands outwardly to assume a predetermined shape at a
particular interior pressure, e.g., an envelope with a fixed
configuration. Alternatively, end 12, balloon 14 and end 18 are
formed from an elastic material. While end 12, balloon 14 and end
18 may be discrete components attached together and have different
expansion characteristics, it is preferable that a single
contiguous piece of material be used to construct all three.
[0046] Distal end 12 defines a volume contiguous with that volume
defined by balloon 14. Distal end 12 is shown tapered and closed so
that it may be used as a probe for threading device 10 through a
lumen. Alternatively, distal end 12 may be arcuate and may have a
channel formed in it for the placement of a guide wire on which
device 10 could travel. As a further alternative, distal end 12 may
be open-ended, e.g., as shown at 42 in FIG. 2.
[0047] Balloon 14 comprises a generally cylindrical balloon (as
previously defined) which defines a generally cylindrical volume,
has a relatively uniform and continuous surface. Preferably,
balloon 14 and distal end 12 are formed without seams therebetween
and do not leak. Alternatively, balloon 14 may comprise a chamber
independent from distal end 12, e.g., without fluidic
connection.
[0048] Proximal end 18 defines a volume contiguous with that volume
defined by balloon 14 and is shown tapered. Preferably, proximal
end 18 is open to provide a flow path for fluid to be flowed into
balloon 14. Balloon 14 includes a plurality of discontinuous
stiffening members 16, preferably aligned along balloon 14 in
separate longitudinal rows of stiffening members arranged radially
around the perimeter of balloon 14.
[0049] The individual stiffening members 16 are preferably made of
a uniform material but may be made of different materials.
Preferably, individual stiffening members 16 are formed from a
flexible metal, plastic or fiber material; a composite material; or
the like. Such materials are preferably inert and compatible with
usage in the human body. Stiffening members 16 may be smooth or
roughened. In an alternative embodiment, stiffening members 16 may
be made of the same materials of which the balloon is made.
Alternatively, a compatible material that is more rigid than the
material of balloon 14 may be used. As a further alternative, a
material or composite that is flexible in one direction but rigid
in another may be utilized.
[0050] The rigidity and flexibility of stiffening members 16 is
preferably matched for a desired purpose utilizing the various
embodiments of stiffener configurations described herein. Longer
and more rigid stiffeners may be advantageously utilized to dilate
tougher occlusive material. Shorter and more flexible stiffeners
may be advantageously utilized to more easily navigate through
contorted passages. Stiffening members 16 may be more rigid than a
stent or stent-graft that they carry.
[0051] Stiffening members 16 may be attached to balloon 14 by
conventional adhesive, constructed as part of the material of
balloon 14, patterned as layers upon balloon 14 or embedded in
balloon 14. Alternatively, stiffening members 16 may be constructed
as part of a sleeve or sheath that is fit over balloon 14 or as
part of a sheet that is wrapped around balloon 14.
[0052] Device 10 may be attached to a separate catheter apparatus
(not shown) or integrated therewith. For example, to attach device
10 to such a catheter directly, proximal end 18 or distal end 12
may be tapered to form a cylindrical section approximately the
cross-sectional size of the catheter and bonded to the catheter
with a bonding agent or an adhesive, or by ultrasonic welding or
the like. Alternatively, device 10 may be folded within a catheter
and carried therein.
[0053] In operation, device 10 is navigated through passages to a
target lumen. The discontinuities in stiffening members 16 and the
flexibility of balloon 14 allow device 10 to pass through curved
passages by bending device 10 at the discontinuities. Upon reaching
the target lumen, a fluid is flowed through proximal end 18 into
balloon 14 and distal end 12 to expand balloon 14. Balloon 14
expands radially and stiffening members 16 contact the inner
surface of the target lumen. Stiffening members 16 act to focus the
expansion force of balloon 14 at the occlusions in the lumen
contacted by members 16. As the interior pressure of balloon 14 is
increased, members 16 engage, cut, pierce or crush the occlusions,
facilitating dilatation of the target lumen by the expanding
balloon 14.
[0054] Another embodiment of the invention, specifically adapted
for engaging or piercing occlusions in a lumen is shown in FIG. 2.
In FIG. 2, a device 40 comprises a distal end 42, a balloon 44,
longitudinal stiffening members 46, and a proximal end 50. A
catheter 54 is also shown.
[0055] Distal end 42 is the same as distal end 12 except that
distal end 42 is open ended. Distal end 42 is shown attached to
catheter 54 at seal 41. Seal 41 may be formed with a bonding agent,
an adhesive, as a compression seal, or by welding, or the like. As
shown, seal 41 is preferably formed by folding the material of
distal end 42 inward on catheter 54. Alternatively, seal 41 may be
formed by any suitable prior art process for forming a seal between
a balloon and a catheter. Preferably, seal 41 provides a
fluid-tight seal.
[0056] Proximal end 50 is the same as proximal end 18 except that
proximal end 50 includes seal 52. Seal 52 may be created by the
same processes used to create seal 41. Seal 52 provides a seal
between proximal end 50 and catheter 54 and is preferably a
fluid-tight seal.
[0057] Catheter 54 is a catheter for carrying and inflating balloon
44. As shown, balloon 44 is sealed at seal 41 and seal 52 to
catheter 54. Catheter 54 extends through the body of distal end 42,
balloon 44, and proximal end 50 as generally indicated at 56.
Catheter 54 includes flow holes 58 which provide a flow path for a
pressurized liquid to flow from catheter 54 through to the interior
volume of balloon 44. Such flow causes balloon 44 to expand.
Catheter 54 may carry a flexible guidewire (not shown) that extends
through catheter 54 and is slidably adjustable therethrough.
Catheter 54 may include a dedicated longitudinal channel
specifically for carrying the guidewire.
[0058] Balloon 44 is the same as balloon 14 except that balloon 44
bears longitudinally continuous stiffening members 46. One or more
of stiffening members 46 includes one or more projections 48.
Projections 48 may be attached to or integral with members 46. A
plurality of members 46 may be provided on, attached to, or
embedded in balloon 44. Stiffening members 46 and projections 48
may be made of the same materials as members 16 and each may be of
a different material. Projections 48 may be smooth or roughened.
Preferably, projections 48 are 0.004 to 0.015 inches tall and may
be shorter or taller, depending upon the application.
[0059] As balloon 44 is expanded, members 46 focus radial expansion
forces at projections 48 and along the length of each respective
member 46. Projections 48 contact occlusions within a lumen to
engage, incise, pierce, fracture, or crush the occlusions or to
engage an inner surface of the lumen. By engaging the inner surface
of the lumen, projections 48 prevent balloon 44 from slipping
through a lumen as balloon 44 is expanded.
[0060] In an alternate embodiment, balloon 44 is constructed as a
closed-ended balloon, e.g., like balloon 14.
[0061] In a further embodiment of the invention, FIG. 3 shows a
device 60 for deploying a stent 70. Device 60 comprises a distal
end 62, a balloon 64, and a proximal end 68. Distal end 62, balloon
64 and proximal end 68 are the same as distal end 12, balloon 14
and proximal end 18, respectively, except that balloon 64 bears
stiffening members 66. One or more of stiffening members 66
includes one or more projections 72. Projections 72 are
specifically adapted for retaining stent 70 as it is being
positioned or guiding stent 70 as it is expanded in a lumen or
both. Members 66 and projections 72 may be made of the same
material as members 16 and each may be of a different material.
Members 66 and projections 72 may be smooth or roughened.
[0062] Stent 70 is a conventional stent as known in the art. As
shown, stent 70 may include circumferentially expandable members 74
and longitudinally expandable members 76.
[0063] In a preferred operation, balloon 64 is expanded and the
radial force of expansion is focused by members 66 on portions of
stent 70, preferably members 74. Members 66, disposed at intervals
along the perimeter of balloon 64 facilitate uniform expansion and
deployment of stent 70. Members 66 may match the stent in length or
extend beyond the ends of the stent to minimize flaring of the ends
of the stent. Projections 72 act to prevent stent 70 from
separating from (e.g., slipping off), balloon 64 as balloon 64 is
expanded. Alternatively, if members 66 are specifically placed at
only selected locations on balloon 64, a custom, non-uniform
expansion and deployment of stent 70 can be achieved.
[0064] Besides assisting in the expansion of stent 70, device 60
may additionally or alternatively assist in the positioning of
stent 70 during a deployment. Projections 72 may hold stent 70 in
place on balloon 64 as the entire device is navigated through a
passage and precisely located.
[0065] As a further alternative, either or both projections 72 and
members 66 may be utilized to additionally engage, incise, pierce,
fracture or crush occlusions encountered in a lumen during or after
deployment of stent 70. Specifically, portions of projections 72 or
members 66 may extend radially beyond the surface of stent 70 and
may extend through stent 70. Optionally, either or both projections
72 and members 66 may interdigitate with complementary interface
structure of stent 70. As illustrated, projections 72 may
interdigitate with one or more of expandable members 74 and 76.
[0066] The height of projections 72 preferably match the thickness
of the device which is carried on the balloon. It is further
preferred, where engagement with the lumen is desired, that the
height of projections 72 exceeds the thickness of the device
carried on the balloon and that such height be even greater where
piercing of an occlusion is desired.
[0067] In an alternate preferred embodiment, each of projections 72
is configured as a post (see FIG. 10E) which fits within a
complementary slot located in stent 70. In general, each of
projections 72 may be individually designed to interlock or
otherwise removably couple with complementary corresponding
structure provided on an expandable device, such as stent 70.
[0068] FIG. 4 shows a conventional stent-graft 90 as known in the
art. As shown, stent-graft 90 includes expandable radial members 92
and mesh 94. Stent-graft 90 may be substituted with any
conventional stent-graft. In the same manner that device 60 may be
utilized to position, expand and deploy stent 70, stent-graft 90
may be similarly positioned, expanded and deployed.
[0069] In each of devices 10, 40 and 60 the respective stiffening
members may be positioned on the outside of the balloon as shown in
FIG. 5A, in the balloon material as shown in FIG. 5B, on the inside
of the balloon as shown in FIG. 5C, or collected in a selected area
as shown in FIG. 5D.
[0070] FIG. 5A shows a cross-sectional view of a device 100
comprising a balloon 102 according to the present invention having
evenly-spaced external stiffening members 104. Also shown is a
stiffening member 106 having a radio-opaque portion 108. Portion
108 may be made radio-opaque as described hereinbelow. FIG. 5B
shows a cross-sectional view of a device 110 comprising a balloon
112 according to the present invention having embedded stiffening
members 114. FIG. 5C shows a cross-sectional view of a device 120
comprising a balloon 122 according to the present invention having
internally-located stiffening members 124. FIG. 5D shows a
cross-sectional view of a device 130 comprising a balloon 132
according to the present invention having members 134 and 136
located in a localized area on the perimeter of balloon 132.
Members 134 and 136 may have the same or different (as shown)
cross-sections.
[0071] In an alternate embodiment, FIGS. 5A, 5B, 5C and 5D
illustrate the positioning of individual projections 104 and 106;
114; 124; and 134 and 136, respectively, on a balloon.
[0072] FIGS. 6A, 6B and 6C show alternative configurations for
stiffening members according to the present invention. Each such
configuration specifically creates a portion of the stiffening
member where it may flex or pivot to facilitate navigation of the
stiffening member through a curved passage. FIG. 6A shows a
stiffening member 160 having a localized narrow area 162 which
facilitates the flexing or pivoting of member 160 at an area 162.
FIG. 6B shows a stiffening member 170 having a narrowed area 172
comprising cut-outs 174 and 176 which facilitate the flexing or
pivoting of member 170 at an area 172. FIG. 6C shows a stiffening
member 180 having narrowed areas 182 and 183 created by triangular
cut outs 184 and 186, 188 and 190, respectively. Each of narrowed
areas 182 and 183 is a point at which member 180 may flex or
pivot.
[0073] FIGS. 7A-7G show alternative designs for stiffening members
according to the present invention. Each such alternative design
provides discontinuous stiffening members that may be
advantageously navigated through curved passages. FIG. 7A shows
members 200 comprising end pieces 202 and interior pieces 204.
Alternatively, one or more of pieces 202 and pieces 204 may be
omitted. FIG. 7B shows members 220 comprising end pieces 222,
having projections 224, and interior pieces 226 having projections
228. FIG. 7C shows members 240 comprising end pieces 242 and
interior pieces 244. FIG. 7D shows members 260 comprising end
pieces 262 and "S"-shaped interior pieces 264. FIG. 7E shows
members 280 comprising "L"-shaped pieces 282 and 284. FIG. 7F shows
members 300 comprising end pieces 302 and interior pieces 304. It
should be noted that the surface area of interior pieces 304 along
the surface of the balloon is greater than the surface area of
pieces 308. As a consequence, upon expanding the balloon, pieces
306 will protrude above the upper surfaces of pieces 308.
[0074] FIG. 7G shows members 320 comprising pieces 322 connected by
filaments 324. Filaments 324 are preferably flexible but inelastic
to limit the variation in positioning of members 320.
Alternatively, filaments 324 are elastic.
[0075] FIGS. 8A-I show cross-sectional views of numerous stiffening
members according to the present invention. In FIG. 8A, a
capsule-shaped cross-section 350 is shown. In FIG. 8B, a
capsule-shaped cross-section 360 upon which a projection 362 is
located is shown. In FIG. 8C, an arcuate cross-section 370 is
shown. In FIG. 8D, an arcuate cross-section 380 with projection 382
is shown. In FIG. 8E, a crescent-shaped cross-section 390 is shown.
In FIG. 8F, a triangular cross-section 400 is shown. In FIG. 8G, a
rectilinear cross-section 410 is shown. Alternatively, it is
contemplated that cross-section 410 may be modified by rounding its
corners. In FIG. 8H, a circular cross-section 420 is shown. In FIG.
81, an acute triangular cross-section 430 is shown.
[0076] FIGS. 9A-J show perspective views of alternative embodiments
of stiffening members according to the present invention. In FIG.
9A, a disc-shaped member 440 is shown. In FIG. 9B, an
elliptical-shaped member 450 is shown. In FIG. 9C, a
triangular-shaped member 460 is shown. In FIG. 9D, a
rectilinear-shaped member 470 is shown. In FIG. 9E, a
hexagonal-shaped member 480 is shown. In FIG. 9F, a
trapezoidal-shaped member 490 is shown. In FIG. 9G, a sawtooth
member 500 is shown. In FIG. 9H, a "Z"-shaped member 510 is shown.
In FIG. 9I, an "L"-shaped member 520 is shown. In FIG. 9J a chair
shaped member 530 is shown.
[0077] FIGS. 10A-G show alternate embodiments of projections
according to the present invention. FIG. 10A shows a rounded
projection 540. FIG. 10B shows a conical projection 550. FIG. 10C
shows a pointed projection 560. FIG. 10D shows a pyramidal
projection 570. FIG. 10E shows a post projection 580. FIG. 1OF
shows a "U"-shaped projection 590. FIG. 10G shows a "C"-shaped
projection 592. Projection 540 is particularly adapted to crushing
an occlusion. Projections 550, 560 and 570 are particularly adapted
to engaging and piercing an occlusion and may be utilized to hold a
stent or stent-graft. Projection 580 is the preferred embodiment of
a projection for interdigitating or otherwise interfacing with a
stent or stent-graft. Projection 590 provides a more complex
structure for interdigitating with complementary structure on a
stent or stent-graft and may be used to couple to a specific
transversely oriented structural element of such a stent or
stent-graft. Similarly, projection 592 may be utilized to hook or
otherwise clamp a stent or stent-graft and may be particularly
useful in exerting a pulling force. Projections 580, 590 and 592
may have blunt or pointed ends.
[0078] FIG. 11 illustrates a system 600 of interconnected
projections. Projections 602 and 604 are connected by filaments
606. Filaments 606 may be comprised of an inelastic material or
alternatively may be formed from an elastic material. Preferably,
filaments 606 limit the variation in the positioning of the
projections relative to each other. In this manner a network of
projections may be interconnected to form a sheet, sheath or sleeve
of projections that may be attached to a balloon.
[0079] Any of the stiffening members, projections or filaments
described in the foregoing may be rendered opaque to x-rays or
other radiation (collectively, "radio-opaque") to facilitate
determination of the position of the balloon within a blood vessel
and its position relative to the target lumen. In addition,
radially arranged radio-opaque stiffeners or projections may be
referenced to determine the degree of balloon expansion as a
balloon is inflated. A single stiffening member that is
radio-opaque along its length may be referenced to determine the
axial and radial orientation of the balloon, including the amount
of axial rotation. The stiffening members, projections and
filaments may be made radio-opaque by conventional techniques, such
as surface coating or printing, incorporation of radio-opaque
material into the substance of the stiffening member (e.g., barium
or bismuth salts blended into patterns) or construction of the
stiffening member of a material with inherent radio-opacity, such
as metallic tungsten.
[0080] A longitudinal stiffener with a longitudinally radio-opaque
portion is advantageously utilized to reconfigure an expandable
device that is already deployed within a lumen. Where such device
has been deployed but requires reconfiguration, the position of the
radio-opaque portion of the stiffener may be referenced to
determine the location of the stiffener and guide its alignment
with the expandable device. If a portion of the device requires
further expansion, a small number of longitudinal stiffeners on a
balloon may be aligned with the portion of the device requiring
expansion to focus the radial force of expansion at the particular
portion of the device. In this manner, a stiffened balloon with a
longitudinal stiffener having a radio-opaque portion may be
utilized to specifically further expand an end of a stent-graft
that has not been properly deployed and has resulted in an
endoleak.
[0081] For example, a balloon with a single radio-opaque
longitudinal stiffener may be rotated to align the stiffener with
an unexpanded portion of the stent-graft and expanded. Upon
expansion of the balloon, the stiffener will exert a focussed force
against the unexpanded portion of the stent-graft while the
remainder of the balloon will exert less force at all other
positions on its surface. Accordingly, the unexpanded portion of
the stent-graft will be further expanded but the remainder of the
stent-graft will not be expanded at all or will be expanded much
less.
[0082] Similarly, utilizing a suitable configuration of
projections, a stiffened balloon bearing a stiffening member having
a projection may be utilized to push or pull a device expanded in a
lumen to reposition it. Upon expansion of the balloon, the
projection is oriented to fit a complementary interface at the
device. The projection and the interface are connected and the
device is repositioned by changing the position or orientation of
the stiffened balloon.
[0083] While preferred embodiments of the invention have been
described with particularity and with reference to the drawings,
modifications and variations of the foregoing will be apparent to
those of skill in the art utilizing the techniques disclosed
herein. It is, therefore, to be understood that such embodiments
are illustrative and not limiting on the scope of the present
invention and that the invention encompasses such modifications and
variations.
* * * * *