U.S. patent application number 17/136570 was filed with the patent office on 2021-06-24 for balloon assemblies having controllably variable topographies.
The applicant listed for this patent is W. L. Gore & Associates, Inc.. Invention is credited to John E. Bacino, Carey V. Campbell, Edward H. Cully, Jeffrey B. Duncan, Douglas S. Paget, Edward E. Shaw, John M. Squeri, Benjamin M. Trapp, Michael J. Vonesh.
Application Number | 20210186555 17/136570 |
Document ID | / |
Family ID | 1000005436621 |
Filed Date | 2021-06-24 |
United States Patent
Application |
20210186555 |
Kind Code |
A1 |
Bacino; John E. ; et
al. |
June 24, 2021 |
BALLOON ASSEMBLIES HAVING CONTROLLABLY VARIABLE TOPOGRAPHIES
Abstract
Various embodiments provide a device comprising a balloon
assembly including a balloon, a film template, and a rigid element.
The film template may have a fixed upper distension limit and may
include at least one aperture. The rigid element may lay
substantially flush with an outer surface of the balloon at a first
inflated state of the balloon. The first upper distension limit of
the balloon may be greater than the fixed upper distension limit of
the film template and the balloon may outwardly protrude through
the at least one aperture at a second inflated state. The rigid
element may be extended in a radial direction away from the outer
surface of the balloon as the balloon outwardly protrudes through
the at least one aperture relative to the outer surface of the film
template.
Inventors: |
Bacino; John E.;
(Landenberg, PA) ; Campbell; Carey V.; (Flagstaff,
AZ) ; Cully; Edward H.; (Flagstaff, AZ) ;
Duncan; Jeffrey B.; (Flagstaff, AZ) ; Paget; Douglas
S.; (Flagstaff, AZ) ; Squeri; John M.;
(Downingtown, PA) ; Trapp; Benjamin M.;
(Flagstaff, AZ) ; Vonesh; Michael J.; (Flagstaff,
AZ) ; Shaw; Edward E.; (Flagstaff, AZ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
W. L. Gore & Associates, Inc. |
Newark |
DE |
US |
|
|
Family ID: |
1000005436621 |
Appl. No.: |
17/136570 |
Filed: |
December 29, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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15645176 |
Jul 10, 2017 |
10881426 |
|
|
17136570 |
|
|
|
|
13645414 |
Oct 4, 2012 |
9730726 |
|
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15645176 |
|
|
|
|
61545039 |
Oct 7, 2011 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61M 2025/1031 20130101;
A61M 25/1027 20130101; A61M 2025/1086 20130101; A61B 17/320725
20130101; A61M 25/1002 20130101; Y10T 29/49826 20150115; A61M
2025/105 20130101; Y10T 29/49888 20150115; A61M 25/104 20130101;
A61M 25/10184 20131105; A61M 25/1029 20130101; A61M 2025/1059
20130101; A61M 2025/1084 20130101 |
International
Class: |
A61B 17/3207 20060101
A61B017/3207; A61M 25/10 20060101 A61M025/10 |
Claims
1. A medical balloon comprising an inflatable balloon element; a
template having an outer surface and extending along at least a
portion of the inflatable balloon element for at least a portion of
its length and having an first distension profile and a second
distension profile; wherein the template includes at least one
aperture, wherein the inflatable balloon element outwardly extends
about the at least one aperture relative to the outer surface of
the template when inflated to the first distention profile, and
wherein the inflatable balloon element forms a relatively smooth
surface about the at least one aperture relative to the outer
surface of the film template when inflated to the second distention
profile.
2. The medical balloon of claim 1, wherein the template comprises a
first nominal size at the first distention profile and a second
nominal size at the second distension profile, wherein the the
first nominal size is less than the second nominal size.
3. The medical balloon of claim 2, wherein when the inflatable
balloon element is inflated to a first pressure, the template is at
a first distension pressure and when the inflatable balloon element
is inflated to a second pressure, the template is at a second
distension profile.
4. The medical balloon of claim 1, wherein the inflatable balloon
element is size limited.
5. The medical balloon of claim 4, wherein the inflatable balloon
element is strained during inflation.
6. The assembly of claim 1, wherein inflatable balloon comprises a
size limiting layer.
7. The assembly of claim 4, wherein the size limiting layer
comprises at least two layers of a helically wrapped polymeric
tape.
8. The assembly of claim 1, further comprising a therapeutic agent
underlying the film template, wherein at least a portion of the
therapeutic agent is conveyed out of at least one aperture upon the
balloon extending through the aperture.
9. The assembly of claim 1, wherein the film template comprises a
rigid element.
10. The assembly of claim 9, wherein the inflatable balloon element
outwardly rotates the rigid element during inflation.
11. The assembly of claim 1, wherein the inflatable balloon element
is configured to perfuse.
12. The assembly of claim 1, wherein the template comprises a
high-strength ePTFE.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation application of U.S.
application Ser. No. 15/645,176, filed Jul. 10, 2017, now U.S. Pat.
No. 10,881,426, issued Jan. 5, 2021, which is a continuation
application of U.S. application Ser. No. 13/645,414 filed on Oct.
4, 2012, now U.S. Pat. No. 9,730,726, issued Aug. 15, 2017, which
claims priority to U.S. Provisional Application No. 61/545,039,
filed Oct. 7, 2011, wherein the above-listed applications are
hereby incorporated by reference in their entireties.
BACKGROUND OF THE DISCLOSURE
Field of the Disclosure
[0002] The present disclosure relates generally to balloon
assemblies having controllable topographies and systems and methods
relating to the same.
Discussion of the Related Art
[0003] Balloons intended for use within a mammalian body, such as a
human, are employed in a variety of medical procedures, including
dilation of narrowed blood vessels, placement of stents and other
implantable devices, temporary or permanent occlusion of blood
vessels, drug delivery, thrombectomy, embolectomy, atherectomy,
angioplasty, other endovascular procedures, and other procedures
within a lumen of a mammalian body such as a human body. In this
regard, as used herein, the term "body" can comprise a mammalian
body such as a human body or other animal body.
[0004] In a typical application, a balloon (often coupled with a
catheter) is advanced to the desired location in the vascular
system or other lumen of the body. The balloon is then
pressure-expanded in accordance with a medical procedure.
Thereafter, the pressure is removed from the balloon, allowing the
balloon to contract and permit removal of the catheter and, in many
cases, the balloon.
[0005] Procedures such as these are generally considered minimally
invasive, and are often performed in a manner which minimizes
disruption to the patient's body. As a result, balloons are often
inserted from a location remote from the region to be treated. For
example, during angioplasty procedures involving coronary vessels,
the balloon catheter is typically inserted into the femoral artery
in the groin region of the patient, and then advanced through
vessels into the coronary region of the patient. These balloons
typically include some type of radiopaque marker to allow the
physician performing the procedure to monitor the progress of the
catheter through the body.
[0006] Non-compliant balloons are generally made of relatively
strong but generally inelastic material (e.g., nylon, polyester,
etc.), which must be folded to obtain a compact, small diameter
cross section for delivery. These relatively stiff balloons do not
easily conform to the surrounding vessel and thus can be used to
compact hard deposits in vessels. Due to the need for strength and
stiffness, these devices are rated to employ high inflation
pressures, usually up to about 4 to about 60 atmospheres. As
depicted in FIG. 1, non-compliant balloons (line C) have a maximum
diameter, and as inflation fluid is introduced, such balloons will
not normally distend appreciably beyond a maximum diameter. Once a
non-compliant balloon is inflated to its maximum diameter, the
exertion of additional pressure can cause rupture of the balloon,
creating a hazardous condition.
[0007] By contrast, compliant balloons generally comprise soft,
elastic material (e.g., natural rubber latex). As depicted in FIG.
1, compliant balloons (line A) will generally expand continuously
in diameter and will not appreciably increase in internal pressure
as inflation fluid is introduced. As a result, compliant balloons
are generally rated by volume (e.g., 0.3 cc) rather than by nominal
diameter. Also, compliant balloons generally conform to the shape
of the vessel. Although comparatively weak compared to
non-compliant balloons, compliant balloons have the advantage that
they need not be folded about a delivery catheter (reducing
profile) and tend to readily recompact to their initial size and
dimensions following inflation and subsequent deflation. These
balloons can be employed to displace soft deposits, such as a
thrombus, where a soft and tacky material such as latex provides an
effective extraction means, and also can be used as an occlusion
balloon, operating at low pressures.
[0008] In between the spectrum of compliant balloons and
non-compliant balloons fall semi-compliant balloons. As depicted in
FIG. 1, semi-compliant balloons (line B) will both increase in
pressure and increase in diameter as inflation fluid is introduced.
However, semi-compliant balloons operate at pressures in between
the two types of balloons and will continue to distend as inflation
fluid is introduced.
[0009] Both compliant and non-compliant balloons tend to have a
uniform surface topography. In other words, conventional balloons
tend to have smooth surfaces. Balloons with more varied
topographies may facilitate a variety of medical procedures and
therapies not possible using conventional balloons. For instance, a
variable topography may provide increased surface area over a
similar conventional balloon, and thus interaction with the body
may be improved. A variable topography balloon may also be
configured to deploy sharp objects in a localized, difficult to
reach part of the body, providing an improvement in therapy. In
addition, variable topography balloons may provide improved drug
delivery systems. Moreover, it would be beneficial for a balloon to
have a controllable topography.
SUMMARY OF THE DISCLOSURE
[0010] The present disclosure provides systems and methods for
balloon assemblies having varied topographies and pre-configured
surface textures. In various embodiments, a device is provided
comprising a balloon comprising a size limiting layer and a
template disposed around or within the balloon. The template
comprises at least one aperture and a portion that is more
resistant to deformation in a radial direction than the balloon or
the size limiting layer, either because template comprises a less
compliant material or has an upper distension limit that is less
than the size limiting layer's upper distension limit. As such, the
balloon and size limiting layer are configured to distend beyond
the template about the aperture at a given volume/pressure. The
balloon and size limiting layer will distend about an aperture to a
second inflated state comprising a varied topography. The size
limiting layer prevents further appreciable distension beyond the
second inflated state. In various embodiments, the template and/or
balloon can optionally comprise an expanded polytetrafluoroethylene
(ePTFE). The balloon and/or template can comprise a tape wrapped
membrane. Other embodiments comprise methods of making and using
the same.
[0011] In various embodiments, a balloon assembly is provided
comprising a balloon having a controlled topography, wherein the
balloon assembly has a smooth or substantially wrinkle free surface
at a first inflated state and a varied topography surface at a
second inflated state. In an embodiment wherein the balloon
assembly comprises an inner balloon and an outer template, the
inner diameter of the template at a first inflated state is
substantially equal to the outer diameter of the balloon at a first
inflated state. In an embodiment wherein an outer balloon is
disposed around an inner template, the converse is true; namely,
the outer diameter of the template at a first inflated state is
substantially equal to the inner diameter of the balloon in the
first inflated state. The balloon and/or template can comprise a
tape wrapped membrane. Other embodiments comprise methods of making
and using the same.
[0012] In other embodiments, a balloon assembly can comprise an
underlying compliant balloon and an overlying less compliant
template having at least one aperture. Located within the aperture
can be a therapeutic agent, preferably in a solid or viscous form.
Upon inflation, the underlying compliant balloon will protrude
through the aperture and convey the therapeutic agent external to
the template. In this manner, a therapeutic agent can be delivered
to a surrounding tissue such as the intima of a vessel. Other
embodiments include methods of making and using the same.
[0013] Another aspect of the present disclosure comprises textured
balloon assemblies. In various embodiments, a balloon can be
covered and/or wrapped with a textured network that provides a
topographical feature. For example, a textured network can comprise
beads, filaments, fibers, rings, knits, weaves, and/or braids,
which can be wrapped or otherwise disposed over or within a
balloon. The textured network creates raised surface patterns that
can provide therapeutic effect. Other embodiments include methods
of making and using the same.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The accompanying drawings are included to provide a further
understanding of the present disclosure and are incorporated in and
constitute a part of this specification, illustrate embodiments of
the present disclosure, and together with the description serve to
explain the principles of the disclosure.
[0015] FIG. 1 compares pressure to height of complaint balloons
(Line A), semi-compliant balloons (Line B), and non-compliant
balloons (Line C);
[0016] FIG. 2A illustrates a schematic varied topography balloon
assembly embodiment from a cross-sectional perspective;
[0017] FIGS. 2B(1) to 2B(3) illustrates a varied topography balloon
assembly embodiment of the present disclosure in a deflated state;
a first inflated state; and a second inflated state;
[0018] FIG. 2B(4) illustrates a close up, cross-sectional view
about an aperture of a varied topography balloon assembly
embodiment illustrated in FIG. 2B(3);
[0019] FIGS. 3A(1) to 3A(3) schematically illustrate the process
under which various embodiments distend to a second inflated state
thereby forming a varied topography balloon assembly;
[0020] FIGS. 3B(1) to 3B(3) schematically illustrate the process
under which various embodiments distend to a second inflated state
thereby forming a varied topography balloon assembly;
[0021] FIGS. 4A to 4D illustrate wrapping a film tape to form a
size limiting membrane layer;
[0022] FIG. 5A schematically illustrates a balloon assembly
embodiment comprising a tapered balloon and/or size limiting
layer;
[0023] FIG. 5B schematically illustrates a balloon assembly
embodiment comprising a tapered template;
[0024] FIGS. 6A and 6B illustrate a cross-sectional view of a
varied topography balloon assembly embodiment wherein a plurality
of apertures are located on a first section of the template and no
apertures are located on a second section of tem plate;
[0025] FIG. 7 A schematically illustrates a varied topography
balloon assembly embodiment of the present disclosure comprising
two templates;
[0026] FIG. 7B illustrates a close up, cross-sectional view about
an aperture of a varied topography balloon assembly embodiment
illustrated in FIG. 7A;
[0027] FIG. 8 illustrates a varied topography balloon assembly
comprising a therapeutic agent, in accordance with various
embodiments;
[0028] FIG. 9 illustrates a varied topography balloon assembly
embodiment wherein the balloon comprises a wall with regions of
reduced compliance than other more distensible regions;
[0029] FIG. 10A illustrates a cross-sectional view of a balloon
assembly embodiment wherein the overlying template comprise rigid
elements;
[0030] FIG. 10B illustrates a cross-sectional view of a balloon
assembly embodiment depicted in FIG. 10A with the rigid elements
outwardly rotated;
[0031] FIG. 10C illustrates a cross-sectional view of a balloon
assembly embodiment wherein the overlying template comprises rigid
elements having a piercing or sharp tip that is attached to
template at its proximal base;
[0032] FIG. 10D illustrates a cross-sectional view of a balloon
assembly embodiment wherein the overlying template comprises rigid
elements of FIG. 10C outwardly rotated;
[0033] FIG. 10E illustrates a cross-sectional view of a balloon
assembly embodiment wherein the overlying template comprises rigid
elements having a lumen therethrough which is in fluid
communication with the balloon;
[0034] FIG. 11 illustrates an inflated balloon assembly comprising
a wire tem plate;
[0035] FIG. 12 illustrates a balloon assembly in accordance with
various embodiments within the vasculature;
[0036] FIGS. 13A to 13C illustrate a textured balloon assembly in
accordance with various embodiments;
[0037] FIG. 13D illustrates a cross sectional view a textured
balloon assembly on a mandrel, in accordance with various
embodiments;
[0038] FIG. 14A illustrates a deflated balloon assembly with a
scored template pattern from an exterior perspective, in accordance
with various embodiments;
[0039] FIG. 14B illustrates an inflated balloon assembly with a
deployed scored template pattern from an exterior perspective, in
accordance with various embodiments;
[0040] FIG. 14C(1) illustrates a close-up, perspective view of a
deflated balloon assembly with an arced element across the aperture
of a template, in accordance with various embodiments;
[0041] FIG. 14C(2) illustrates a close-up, perspective view of an
inflated balloon assembly with a deployed arced element across the
aperture of a template, in accordance with various embodiments;
[0042] FIG. 14C(3) illustrates a close-up, side view of the
inflated balloon assembly of FIG. 14C(2), in accordance with
various embodiments;
[0043] FIG. 14D(1) to 14D(4) illustrate the various patterns of
template comprising an arced element across the aperture;
[0044] FIG. 14E(1) illustrates a close-up, perspective view of a
deflated balloon assembly with an arced element across the aperture
of a template, in accordance with various embodiments;
[0045] FIG. 14E(2) illustrates a close-up, perspective view of the
inflated balloon assembly of FIG. 14E(1), in accordance with
various embodiments;
[0046] FIG. 15 illustrates a method of making, in accordance with
various embodiments;
[0047] FIG. 16 illustrates a method of use, in accordance with
various embodiments;
[0048] FIG. 17 illustrates a balloon assembly embodiment wherein a
template is located on an intermediate section of a balloon;
[0049] FIG. 18 illustrates a balloon assembly embodiment wherein
the balloon and size limiting layer is perfusable;
[0050] FIGS. 19A-B illustrates a varied topography balloon assembly
embodiment wherein the balloon comprises a wall with regions of
reduced compliance than other more distensible regions;
[0051] FIGS. 20A-20B illustrates a varied topography balloon
assembly with a stent device mounted thereon, the stent device
having deployable anchors which are actuated by protruding
apertures; and
[0052] FIG. 21 illustrates a varied topography balloon assembly
wherein an aperture or a plurality of apertures are located on a
circumferential section.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS
[0053] Persons skilled in the art will readily appreciate that
various aspects of the present disclosure can be realized by any
number of methods and apparatuses configured to perform the
intended functions. Stated differently, other methods and
apparatuses can be incorporated herein to perform the intended
functions. It should also be noted that the accompanying drawing
figures referred to herein are not all drawn to scale, but can be
exaggerated to illustrate various aspects of the present
disclosure, and in that regard, the drawing figures should not be
construed as limiting. Finally, although the present disclosure can
be described in connection with various principles and beliefs, the
present disclosure should not be bound by theory.
[0054] As used herein, "balloon assembly" means a balloon coupled
with one or more other components, such as a template (described
herein), size limiting layer (descried herein), catheter, distal
cap ("olive"), cover, or other apparatus.
[0055] As used herein, the term "size limiting" means that a
material or component has an upper distension or deformation limit
beyond which a material or component will not appreciably expand,
distend, and/or deform. For example, a size-limited balloon can be
inflated to a maximum diameter, and once this diameter is reached,
further increases in pressure will not cause an appreciable
increase in its diameter. As reflected in FIG. 1, a non-compliant
balloon (line C) is a size-limited balloon, and traditional
compliant (line A) and semi-compliant (line B) balloons are not
size-limited balloons. Accordingly, a "compliant balloon," as used
herein, refers to both compliant and semi-compliant balloons or
balloons that are not size limited, but will continue to expand,
distend, and/or deform as the internal pressure increases until the
point of failure, e.g., the balloon wall ruptures. In accordance
with certain embodiments of the present disclosure, the described
"compliant" balloons are referred to as such because the described
balloons generally conform to the shape of their surroundings
(e.g., a surrounding anatomy or vessel) like traditional
"compliant" balloons, e.g., portions of the described "compliant"
balloons are able to outwardly extend from the template to form
protrusions.
[0056] As used herein, the term "to inflate" can mean to fill or
cause expansion by introducing a flowable substance (e.g., an
influx of fluid), such as a liquid (e.g., saline), a gel, or a
gas.
[0057] As used herein, the term "inflated" means a balloon at an
internal pressure or volume above the internal pressure or volume
at which the balloon begins to expand from a deflated state. As
used herein, a "first inflated state" refers to an inflated balloon
at a first pressure or first volume which will result in a balloon
with a generally smooth or uniform surface, except perhaps with
respect to slight recesses at the site of the aperture(s). As used
herein, a "second inflated state" refers to an inflated balloon at
a second pressure or second volume greater than the first pressure
or first volume which will result in a balloon with a varied
topography. As used herein, "varied topography" refers to a balloon
assembly surface that has textured, bumpy, ribbed, or other
three-dimensional surfaces.
[0058] As used herein, the term "elongate element" is generally any
element configured for relative axial movement with an endoluminal
device delivery element (e.g., a catheter-based endoluminal device
delivery element such as a balloon catheter) and includes any
longitudinally extending structure with or without a lumen
therethrough. Thus, elongate elements include but are not limited
to tubes with lumens (e.g., catheters), solid rods, hollow or solid
wires (e.g., guidewires), hollow or solid stylets, metal tubes
(e.g., hypotubes), polymer tubes, pull cords or tethers, fibers,
filaments, electrical conductors, radiopaque elements, radioactive
elements and radiographic elements. Elongate elements can be any
material and can have any cross-sectional shape including, but not
limited to, profiles that are elliptical, non-elliptical, or
random.
[0059] As described herein, balloon assemblies used inside the body
generally interact with the body through contact with an exterior
surface of the balloon assembly. Thus, the surface topography of a
balloon assembly can affect the physical interaction between the
balloon assembly and the body or a device inside the body. The
ability to control a balloon's topography, or three dimensional
surface characteristics, allows balloon assemblies to interact with
the body in new or improved modes. Various advantages can be
realized using controllably variable topography balloon assemblies.
For example, balloon assemblies, such as those that can be used
with a catheter, can be inserted into a lumen of the body. The
balloon assembly can interact with the body in a variety of ways
which can be facilitated by designing topographies which yield
improved results. In this regard, for example, a balloon having a
varied topography can improve engagement with a vessel wall and/or
improve atherosclerotic plaque or thrombus removal ability, such
from a vessel wall or the wall of an endoprosthesis.
[0060] By selectively constraining the expansion of a balloon at
selected sites, the balloon assembly topography can be varied. For
example, with reference to FIG. 2A, a schematic of a balloon
assembly 200 is shown. FIGS. 2B(1) to 2B(3) illustrate a varied
topography balloon 200 in a deflated state (FIG. 2B(1)), a first
inflated state having a generally uniform or smooth surface (FIG.
2B(2)), and a second inflated state having a varied topography
(FIG. 2B(3)). FIG. 2B(4) illustrates a close-up, cross-sectional
view of a protrusion 212 of a varied topography balloon 200.
[0061] Balloon assembly 200 comprises balloon 210 and template 220.
Balloon 210 can be disposed along template 220, either underlying
or overlying the template 220. The balloon 210 may comprise a
working length and at least one tapered section (i.e., a shoulder).
The template 220 may extend along at least a portion of the working
length of the balloon 210. The template 220 may also extend along
at least a portion of at least one shoulder of the balloon 210.
Assembly 200 can further comprise a catheter 202 to which balloon
210 and template 220 are attached. Catheter 202 is shown in fluid
communication with balloon 210, such that fluid can be introduced
through catheter 202 into balloon 210. Catheter 202 can be coupled
to any suitable medical device, such as a syringe, an indeflator,
pump or any other apparatus for conducting fluid through catheter
202 and into balloon 210.
[0062] Template 220 can be an overlying or underlying structure
comprising at least one aperture 221. Template 220 constrains a
portion of balloon 210 during inflation. In this regard, balloon
210 is inflated to a second inflated state, and the restraining
action of template 220 causes balloon 210 to distend at apertures
221 in template 220 as described in more detail below.
[0063] The operation of the balloon assemblies of the present
disclosure is shown schematically for various embodiments in FIGS.
3A(1) to 3A(3) and 3B(1) to 3B(3) in which is illustrated a
longitudinal cross section of a balloon assembly 300. In FIGS.
3A(1) to 3A(3), balloon 310 underlies template 320 which features
apertures 321. In FIGS. 3B(1) to 3B(3), balloon 310 overlies
template 320, and template 320 adheres to balloon during inflation.
In these illustrations, balloon 310 and template 320 are shown
aligned with axis "A". Axis "A" can comprise the longitudinal axis
of a catheter.
[0064] A first inflated state is shown in FIGS. 3A(2) and. 3B(2).
With reference to FIG. 3A(2), balloon 310 has an outer radius shown
as "R1" under template 320, and template 320 has an inner radius of
"R2". With reference to FIG. 3B(2), balloon 310 has an inner radius
shown as "R1" over template 320, and template 320 has an outer
radius "R2". In the first inflated state, radius "R1" is
substantially equal to radius "R2". No protrusions are observed in
a first inflated state. Stated differently, the height, "H1" of
balloon material or protrusions above template 320 has a value of
zero or close to zero. At the first inflated state, balloon 310
comprises a substantially smooth or wrinkle free surface. Also in
the first inflated state, aperture 321 has a width shown as "W1" in
the figures.
[0065] FIGS. 3A(3) and 3B(3) depict balloon assembly 300 in a
second inflated state. As balloon 110 is inflated beyond a first
inflated state, radius "R2" increases relative to radius "R1" about
aperture 321. This is because balloon 310, upon distention, begins
to distend about or protrude from or above apertures 321. Radius
"R1" remains essentially at the same dimension as in the first
inflated state shown FIGS. 3A(2) and 3B(2). In some embodiments,
width of aperture 321 ("W2") remains close to or even equal to
width of aperture 221 ("W1") in the previous inflated state shown
in FIGS. 3A(2) and 3B(2). In other embodiments, W2 can be greater
than W1; i.e., aperture 320 can increase in size as balloon
assembly 300 is inflated. It will be understood that radius "R2"
can be a maxima, in particular if a size limiting layer or a size
limited balloon is used as described below.
[0066] Referring again to FIGS. 2A and 2B(1) to 2B(4), in various
embodiments, balloon 210 can comprise any suitable compliant
balloon. As described above, a compliant balloon can comprise a
polymeric material. Exemplary materials for a compliant balloon
include elastomers such as polyurethane and silicone, natural
rubber or latex products, synthetic rubber such as nitrile
butadiene, or other synthetic or naturally occurring polymeric
materials. In various embodiments, balloon 210 may not be fully
compliant, but is more compliant than template 220 and sufficiently
flexible to inflate to a diameter larger than the restraining
template 220 diameter at a given pressure, and thereby produces
protrusions 212 (as described below). Thus, a semi-compliant or
non-compliant balloon can be used. In various embodiments, balloon
210 can be conditioned. Conditioning can comprise stretching,
pre-inflating, blow molding, heating, or other process to render
the balloon 210 more amenable to use.
[0067] In various embodiments, balloon assembly 200 can comprise
balloon 210, template 220, and a size limiting layer 215.
Similarly, balloon 210 can comprise a composite material, wherein a
layer of the composite is size limiting layer 215 and/or template
220. Size limiting layer 215 can be disposed about balloon 210,
either between balloon 210 and template 220 or around template 220.
Similar to template 220, size limiting layer 215 is configured to
control the degree of distension of a compliant balloon 210 during
inflation. However, size limiting layer 215 is configured to permit
a degree of distension which is greater than the degree that
template 220 is configured to permit. In this regard, size limiting
layer 215 can possess sufficient flexibility and an upper
distension limit which is larger in diameter than the restraining
template 220 diameter at a given pressure, allowing size limiting
layer 215 to distend about or protrude through aperture 221. In
addition, size limiting layer 215 can be configured to have a
substantially smooth or wrinkle free surface at the first inflated
state. Stated differently, size liming layer is at least slightly
strained at the first inflated state.
[0068] Size limiting layer 215 can be a sheath, sleeve, layer or
other component otherwise configured to at least partially enclose
all or a portion of balloon 210. Size limiting layer 215 can act to
constrain balloon 210 in a substantially uniform manner once
balloon 210 distends to a certain diameter or dimension. Size
limiting layer 215 can be configured to operate at pressures of up
to 2 atm, up to 5 atm, up to 10 atm, up to 15 atm, up to 20 atm, up
to 30 atm, up to 35 atm, up to 45 atm, up to 55 atm, up to 60 atm,
or up to any value between about 2 atm and about 60 atm.
[0069] In various embodiments, size limiting layer 215 can comprise
any flexible, preferably thin material which is inelastic in at
least one orientation or has a suitable upper deformation limit in
at least one orientation. To withstand higher inflation pressures,
size limiting layer 215 can be made of a high strength material.
Size limiting layer 215 can be constructed using any material
described herein for constructing template 220. Size limiting layer
215 can be an extruded or molded tubular form which is at some
point inelastic in a circumferential direction. Alternatively, size
limiting layer 215 can comprise a tape wrapped form wherein the
tape is, at some point, inelastic or has an upper distension limit
in the tapes lengthwise direction.
[0070] To form tape-wrapped size limiting layer 215, with reference
to FIG. 4A to 4D, a thin film can be slit into relatively narrow
widths to form a tape. The tape is helically wrapped onto the
surface of a mandrel 12 in two opposing directions 20 and 22,
thereby forming a tube of at least two layers 14 and 16. Both
layers 14 and 16 can be wrapped with the same pitch angle measured
with respect to the longitudinal axis 18 but measured in opposite
directions. If, for example, the film layers 14 and 16 are applied
at pitch angles of 70.degree. measured from opposite directions
with respect to the mandrel's longitudinal axis 18, then included
angle A between both 70.degree. pitch angles is 40.degree..
[0071] More than two layers of helically wrapped film may be
applied. Alternate layers of film can be wrapped from opposing
directions and an even number of film layers can be used whereby an
equal number of layers are applied in each direction.
[0072] Suitable adhesives may be used to join film wraps together.
Such adhesives include fluorinated ethylene propylene (FEP).
Alternatively, following completion of film wrapping, the helically
wrapped mandrel 12 can be thermally treated at suitable time and
temperature to cause adjacent layers 14 and 16 to heat-bond
together. Regardless of bonding methodology, the size limiting
layer 415 is removed from mandrel 12 and can be placed over the
balloon, tensioned longitudinally as needed and affixed in place
over the balloon.
[0073] During inflation of balloon, size limiting layer 415 can
undergo an increase in diameter which results in included angle A
being substantially reduced as shown by FIG. 4D. Size limiting
layer 415 thus reaches its pre-determined upper distension limit as
included angle A approaches zero. This pre-determined limit is
greater than the distension limit of template in order to yield a
balloon having a varied topography at a second inflated state but
one which does not appreciably distend beyond the second inflated
state.
[0074] Again with reference to FIGS. 2A and 2B(1) to 2B(4), size
limiting layer 215 can optionally be adhered to or laminated with
balloon 210. If adhered, balloon 210 can aid in recompaction of
size limiting layer 215 upon deflation of balloon assembly 200, in
particular if balloon 210 is made of an elastomeric materiel.
Alternatively, a layer of elastomer, applied to a surface of size
limiting layer 215 will cause the size limiting layer 215 to
retract substantially to its pre-inflation size as shown by FIG. 4C
following deflation.
[0075] The film utilized to construct size limiting layer 215 as
described above can comprise any flexible, preferably thin material
that is substantially inelastic or has an upper distension limit in
at least one orientation and has sufficient strength to yield a
balloon 210 that can operate at pressures of up to 2 atm, up to 5
atm, up to 10 atm, up to 15 atm, up to 20 atm, up to 30 atm, up to
35 atm, up to 45 atm, up to 55 atm, or up to 60 atm. For example, a
film can comprise ePTFE. Other suitable film materials can include
other fluoropolymers or non-compliant polymers.
[0076] In various embodiments, size limiting layer 215 can be
constructed or conditioned to constrain balloon 210 upon inflation
to a generally cylindrical inflation profile. Optionally, with
momentary reference to FIG. 5A, size limiting layer 515 can be
configured to alter the general profile of balloon 510, e.g.,
constrain to create a tapered profile, elliptical profile, or a
dumbbell profile. In addition, in the event of a failure of balloon
210 (e.g., a rupture), size limiting layer 215 can act to prevent
release of undesired debris from the disrupted balloon assembly
200.
[0077] In other embodiments, size limiting layer 215 and balloon
210 are combined into a single component. Stated differently,
balloon 210 can comprise a compliant, size limiting material. In
such embodiments, balloon 210 behaves like a compliant or
semi-compliant balloon up to a desired diameter. Once the desired
diameter is reached, balloon 210 behaves like a non-compliant
balloon, allowing the pressure to increase without resulting in an
appreciable increase in a balloon dimension.
[0078] In various embodiments, template 220 comprises any
size-limited form that acts to constrain balloon 210 along the
points of contact. Alternatively, template 220 can comprise a form
less compliant than balloon 210 and/or size limiting layer 215 so
that balloon 210 is constrained along the points of contact. As
such, template 220 is constructed of any material that cannot be
appreciably deformed beyond a first inflated state during inflation
of balloon 210. Template 220 can be configured as a sleeve, layer,
or sheath positioned over balloon 210. For example, template 220
can comprise a generally cylindrical, ellipsoidal, spherical, or
similar form that is disposed substantially coaxial to balloon 210.
Alternatively, template 220 can be an inner layer that constrains a
portion of balloon 210 by being adhered to balloon 200 at selected
portions not comprising an aperture 221.
[0079] In addition, while aperture 221 of template 220 can be
spatially configured to create a varied topography, the
constraining portion of template 220 can also impact the general
profile of balloon 210. For example, as illustrated in FIG. 5B,
template 520, at a first inflated state, can have a diameter that
is larger or smaller at different locations along the balloon 510,
for instance to form a taper. Thus, while balloon 510 can inflate
in the shape of a cylinder, template 520 can have a non-cylindrical
shape, and this non-cylindrical shape can be the general profile of
balloon assembly 500. Such a generally tapered profile can be used
to better conform to cardiovascular vessel diameters which change
over length, for example. In addition, the lesion or thrombus
"scraping" effect of the assembly 500 can be intensified proximally
to distally or vice versa due to the varying profile
dimensions.
[0080] Returning to FIGS. 2A and 2B(1) to 2B(4), template 220 does
not substantially deform beyond a first inflated state or deforms
to a lesser extent than balloon 210 and size limiting layer 215 in
response to inflation of balloon 210. As depicted in FIGS. 2B(3)
and 2B(4), balloon 210 and size limiting layer 215 distends beyond
template 220 about aperture 221 creating a protrusion 212 at a
second inflated state. As shown, at the second inflated state,
inflated balloon assembly 200 can have a varied topography in that
the surface of balloon assembly 200 has a plurality of peaks and
valleys.
[0081] In various embodiments, template 220 can comprise a
size-limited material or configuration. For example, template 220
can be substantially inelastic in at least one direction or
orientation, preferable a direction transverse to the longitudinal
axis of balloon assembly 200 and, in various embodiments, template
220 can also comprise a material that has high tensile strength in
at least one direction. In an alternate embodiment, the template
can comprise a material that has a high strength in both directions
so as to prevent the perimeters of apertures 221 from deforming
upon expansion of balloon 210. In various embodiments, template 220
can comprise a material that is less compliant than balloon 210
and/or template; thus, at a given pressure, balloon 210 will have a
greater degree of distension than template 220.
[0082] In an embodiment, template 220 can comprise a high strength,
yet flexible material such as ePTFE. High strength provides
resistance to deformation in at least one direction such that
template 220 can resist expansion of underlying balloon portions
beyond the application of a particular force caused by balloon
inflation pressures.
[0083] In various embodiments, template 220 can be made from a
thin, high strength film or tape to forming a template. For
example, template 220 can be constructed from a type of ePTFE as
described in U.S. Pat. No. 7,306,729, issued Dec. 11, 2007 and
entitled, "Porous PTFE Materials And Articles Produced Therefrom,"
whose contents are herein incorporated by reference. In various
embodiments, two to sixty layers of ePTFE as described in U.S. Pat.
No. 7,306,729 can comprise template 220. Layers can be
circumferentially (i.e., wrapped at about 90.degree. to the
longitudinal axis) or helically wrapped (as described previously).
In various embodiments, template 220 can be manufactured in a
continuous process and then cut to the desired length before being
disposed on balloons. Optionally, template 220 can be adhered or
laminated to balloon 210 and/or size limiting layer 215.
[0084] Template 220 can comprise other materials, such as other
fluoropolymers, including polytetrafluoroethylenes with different
microstructures from that described in U.S. Pat. No. 7,306,729, so
long as they provide sufficient strength and relative lack of
compliancy, to produce the desired balloon topography and operate
at the previously described pressure thresholds.
[0085] In various embodiments, template 220 can also be
size-limited but compliant. In such embodiments, template 220 can
be formed in a similar manner as size-limited layer and compliant
balloon 210. However, in order to create a varied topography, the
upper distension limit of template 220 must be less than the upper
distension limit of the balloon 210 or the degree of compliancy is
less than that for balloon 210.
[0086] Template 220 can comprise at least one aperture 221 and, in
various embodiments, template 220 can comprise an aperture pattern
and/or a plurality of apertures. Apertures 221 can be present in
template 220 prior to inflation or be formed or increase in size
upon inflation.
[0087] Aperture 221 can comprise an opening or weakened site in the
template material. In this regard, an opening can be a hole, cut,
or any other discontinuous section of the template material. For
example, a hole could be formed by puncturing template 220.
Alternatively, aperture 221 can comprise an area of template 220
where a portion of the material has been removed or otherwise
weakened such that the weakened portion at least partially deforms
or detaches in response to inflation of balloon 210 and permits
distension beyond the first inflated state. Apertures 221 can be
formed by any suitable means, including cutting, stamping, laser
cutting, perforating, and/or punching/puncturing and/or the like.
In various embodiments, template 220 can comprise a net like
structure.
[0088] Optionally, template can comprise apertures that vary in
size. Increasing the size the apertures can allow for a wider (or
"coarser") protrusion. By combining varying aperture sizes with a
tapered template profile, as shown in FIG. 5B, the "scraping"
effect of the assembly can be intensified proximally to distally or
vice versa due to the different protrusion heights.
[0089] With reference again to FIGS. 2A and 2B(1) to 2B(4),
template 220 can be configured such that apertures 221 are formed
or increase in size upon inflation. For example, a template 220
comprising a tape wrapped, woven, or braided membrane around
balloon 210 can be constructed, e.g. wrapped, woven, or braided,
such that apertures 221 are formed by leaving a space between tape
edges and/or apertures 221 form or increase in size between tape
edges upon inflation of balloon 210. In an embodiment, the angle of
the tape material can change relative to the longitudinal axis of
the balloon upon inflation and/or the tape material can narrow in
width as the balloon assembly is expanded, thus creating apertures
221.
[0090] In addition, the varied topography can vary longitudinally
along the length of the balloon and/or can vary circumferentially
about the perimeter of the balloon. For example, with reference to
FIG. 6(A-B), balloon assembly 600 can comprise a template 620
having a first pattern of apertures 621 on first section 650 of
balloon 610 and a second pattern of aperture or zero apertures on a
second section 651. Similarly, the longitudinal and/or
circumferential variation can be random or follow a pre-defined
pattern. Such balloon assemblies can be used for performing
interventional procedures in combination. For example, such a
balloon configured with zero apertures on one half the length of
the balloon assembly and apertures on the remainder of the assembly
can be used to perform both thrombectomy (with the apertured
portion of the assembly) then Percutaneous Transluminal Angioplasty
(PTA) (with the non-apertured portion), all without the exchange of
devices.
[0091] The balloon assembly can be selectively alternated between
the various inflated states, e.g., between a first inflated state
and a second inflations state. A specific inflated state can be
determined by measuring the volume injected into balloon assembly
and/or pressure levels within balloon assembly. By selectively
introducing or withdrawing a fluid by a predetermined amount,
balloon assembly can transition from one inflated state to another.
In an embodiment, the balloon assembly can be configured to pulsate
between the various inflations states.
[0092] In various embodiments, balloon assembly can optionally
comprise a protective cover. A protective cover can be a sleeve or
sheath that covers at least a portion of template. The protective
cover can be delivered with the balloon assembly into the body and
be retracted to expose balloon assembly 200 while within the
body.
[0093] With the described components, one can adapt the compliance
of the balloon, a template, an aperture pattern, inflation
pressures and extensibility of a size limiting layer to control the
topography of a balloon assembly. For example, an aperture pattern
can comprise many small apertures to obtain a "fine texture"
pattern or can comprise fewer larger openings to obtain a more
"coarse texture" pattern. As one can appreciate, any possible
aperture pattern, or combinations of aperture patterns, is
contemplated herein. For example, a first portion of a template can
comprise a square grid like aperture pattern and a second portion
of a template can comprise a diamond shaped pattern.
[0094] In other embodiments, a balloon expanding through a template
can define ridges and troughs which, for example, run parallel to
the longitudinal axis of the balloon. In one embodiment, these
provide for blood perfusion between balloon and vessel wall during
a treatment when the balloon is expanded.
[0095] In other embodiments, protrusions 212 can form at a first
inflated state as depicted in FIG. 2C, and then upon inflation to a
second inflated state, having a pressure greater than the first,
template 220 can distend and the surface of balloon 210 is smooth,
as depicted in FIG. 2B. In an embodiment, template 220 can be
partially or selectively distensible. For example. a 4 mm template
that is distensible up to 8 mm can overlay a balloon and/or a size
limiting layer. Balloon 210 is inflated to 2 atm and the template
acquires its first distension profile so that protrusions form.
Upon further inflation up to 4atm, the template can distend to its
second distension profile or its maximum size. The maximum size of
template 220 can correspond to the maximum size of balloon 210
and/or size limiting layer 215. In other embodiments, template 220
can be frangible and made to break or stretch at a selected
inflation pressure to then reduce the height, at least partially,
of some or all of protrusions 212 to allow for increased contact
between the balloon surface and the target tissue(s) at a higher
pressure. Such embodiments can be used to perform both thrombectomy
(at the first inflated state) then Percutaneous Transluminal
Angioplasty (PTA) (at the second inflated state), all without the
exchange of devices.
[0096] In various additional embodiments, multiple templates can be
used with one compliant balloon to further control and further vary
topography. With reference to FIGS. 7A and 7B, balloon assembly 700
comprises balloon 710 and at least two templates 720 and 725.
Template 720 can be disposed coaxially or substantially coaxially
over balloon 710, and secondary template 725 can be disposed
coaxially or substantially coaxially over template 720. Upon
inflation of balloon 710 to the second inflated state, as depicted
in FIG. 7A, both template 720 and secondary template 725 act to
constrain balloon 710 and have aperture patterns to allow balloon
710 to expand through apertures 721 in each template. In an
embodiment, template 720 and secondary template 725 can act to
shape the topography of inflated balloon assembly 700. Template 720
can create a "coarse" varied topography, and secondary template 725
is selectively positioned to constrain a portion of protrusion 712
and create a "fine" aperture pattern. Protrusion 712 is thus
further constrained by secondary template 725 to form at least two
protrusions or protrusions of different size or shape and create a
finer or varied aperture pattern.
[0097] Optionally, each template can have different upper
distension limits such that the varied topography can vary by
varying the distension of balloon 710. In such embodiments, balloon
assembly 700 can have three or more inflated states. It is
contemplated that any number of templates can be layered in a
balloon assembly to vary and refine topography. In addition,
balloon assembly 700 can optionally comprise a size limiting layer
as described herein.
[0098] FIG. 9 and FIG. 18 illustrate a varied topography balloon
assembly embodiment wherein the balloon comprises a wall with
regions of reduced compliance than other more distensible
regions;
[0099] With reference to FIG. 18, balloon 1810 can comprise a wall
having portions 1817 of reduced or less compliance than other, more
distensible portions 1818 of wall. The other portions 1818 being
essentially the "apertures" that expand outwardly relative to the
portions of reduced or less compliance. The more distensible
portions 1818 can comprise an upper distension limit. The portions
1817 of reduced compliance can be formed through laser
densification or by imbibing with a polymer that reduces the
compliance in the imbibed region. In an embodiment, the regions
1817 of reduced compliance have substantially the same thickness as
the more distensible regions 1818. Similar, with other embodiments
described herein, balloon 1810 can be formed via tape wrapping or
extrusion, and can comprise ePTFE or any other material wherein the
compliancy can be varied at discrete sites.
[0100] Similarly, in an embodiment, the balloon can comprise a
plurality of protrusions in the form of knob-like features. Unlike
the previously described embodiment, the distensiblity of the sites
need not vary along the balloon material. Here, the protrusion is
pre-formed into the balloon. To form a knob-like feature on the
balloon, a balloon form can be placed onto a mandrel or constructed
on a mandrel which has an aperture or recessed site thereon
corresponding to the site of a knob-like feature. In an embodiment,
a heated element can be used to push the knob-like feature into the
aperture or recess and set the feature into the balloon wall.
Similarly, a lower melt thermoplastic material can be imbibed into
the balloon wall at the site of the recess and aperture with the
application of pressure and heat, and allowed to cure while
pressure is still applied and the wall is recessed. In another
embodiment, a vacuum can be applied to the apertures (or pressure
applied to the balloon) such that a recessed site is formed on the
balloon surface. The balloon can then be cured while in this
configuration.
[0101] In further embodiments, with reference to FIG. 19, balloon
assemblies 1900 as described herein can be perfusable. For example,
balloon 1910, size limiting layer 1915, and optionally, template
1920 can comprise a porous material. In addition, balloon 1910,
size limiting layer 1915, and optionally, template 1920 can
comprise a variably perf usable material. In various embodiments,
prior to protrusion, the porosity of the material or the internal
pressure is low enough to not perfuse or minimally perfuse. For
example, upon expansion of balloon 1910 and its protrusion through
apertures 1921, localized forces can cause the microstructure of
the material protruding through apertures 1921 to become more
porous, allowing the therapeutic agent to be released from balloon
1910. In other embodiments, the porosity of the microstructure is
not altered but rather the water entry pressure of the balloon
material is such that the balloon does not perfuse until a certain
threshold pressure. As such, balloon 1919 can be configured not to
perfuse until the second inflated state is obtained. In addition,
balloon 1910 can be configured to perfuse along only a portion,
e.g., the regions of balloon 1910 that upon inflation, protrude
through apertures 1921.
[0102] In various embodiments, a balloon assembly can further
comprise a therapeutic agent disposed on, inside of, temporarily
filling, or otherwise be integrated with the template. Similarly, a
balloon assembly can comprise a therapeutic agent disposed on an
inner or outer surface of the balloon or tem plate, or inside
balloon. In an embodiment, a therapeutic agent can be coated on a
portion of the elongate member underlying the balloon. Therapeutic
agent formula can comprise a liquid or solid form. Liquid from can
be of a desired viscosity suitable for the treatment desired.
[0103] With reference to FIG. 8, balloon assembly 800 comprises
balloon 810 disposed within template 820, and therapeutic agent 808
is disposed between balloon 810 and template 820. Upon inflation of
balloon 810, therapeutic agent 808 can be conveyed through an
aperture 821 of template 820 and be released at a localized portion
of the body. In an embodiment, aperture 821 can form upon inflation
thus containing therapeutic agent 808 until balloon assembly 800 is
inflated.
[0104] Similarly, therapeutic agent can be disposed within
aperture. Upon inflation of balloon, therapeutic agent can be
conveyed beyond aperture by protrusion and be directed to a
surrounding tissue and/or a localized portion of the body. In
various embodiments, the therapeutic agent formula can be in a
solid or viscous form to maintain location within aperture.
Alternatively, therapeutic agent, positioned within aperture can be
protected by a sheath until placed at a treatment site whereupon
the sheath can be retracted.
[0105] In addition, aperture can be configured to limit the release
of therapeutic agent until inflation is underway. For example,
apertures can comprise a conical or other tapered shape, wherein
the aperture defines a smaller area on the outer face than on the
inner face. Aperture can be configured to enlarge upon inflation to
facilitate release of therapeutic agent. In addition, balloon
assembly can comprise a releasable cover to limit or prevent the
release of therapeutic agent.
[0106] Any therapeutic agent that aids in any procedure, e.g.,
diagnostic or therapeutic procedures, or that aids in providing a
therapeutic and/or curative effect is contemplated and suitable for
use with balloon assemblies disclosed herein. In particular,
therapeutic agents that become safer, effective, or achieve another
benefit from localized delivery are useful with balloons disclosed
herein. Among others, suitable therapeutic agents include
anti-proliferative, anti-inflammatory, fibrolytic, thrombolytic,
anti-phlogistic, anti-hyperplastic, anti-neoplastic, anti-mitotic,
cytostatic, cytotoxic, anti-angiogenic, anti-restenotic,
microtubule inhibiting, anti-migration or anti-thrombotic
therapeutic agents.
[0107] For example, suitable therapeutic agents can include:
abciximab, acemetacin, acetylvismione B, aclarubicin, ademetionine,
adriamycin, aescin, afromoson, akagerine, aldesleukin, amidorone,
aminoglutethemide, amsacrine, anakinra, anastrozole, anemonin,
anopterine, antimycotics, antithrombotics, thrombolytics such as
tissue plasminogen activator (tPA), apocymarin, argatroban,
aristolactam-All, aristolochic acid, arsenic and arsenic-containing
oxides, salts, chelates and organic compounds, ascomycin,
asparaginase, aspirin, atorvastatin, auranofin, azathioprine,
azithromycin, baccatine, bafilomycin, basiliximab, bendamustine,
benzocaine, berberine, betulin, betulinic acid, bilobol, biolimus,
bisparthenolidine, bleomycin, bombrestatin, boswellic acids and
their derivatives, bruceanoles A, B and C, bryophyllin A, busulfan,
antithrombin, bivalirudin, cadherins, camptothecin, capecitabine,
o-carbamoylphenoxyacetic acid, carboplatin, carmustine, celecoxib,
cepharanthin, cerivastatin, CETP inhibitors, chlorambucil,
chloroquine phosphate, cictoxin, ciprofloxacin, cisplatin,
cladribine, clarithromycin, colchicine, concanamycin, coumadin,
C-Type natriuretic peptide (CNP), cudxaisoflavone A, curcumin,
cyclophosphamide, cyclosporine A, cytarabine, dacarbazine,
daclizumab, dactinomycin, dapson, daunorubicin, diclofenac,
1,11-dimethoxycanthin-6-one, docetaxel, doxorubicin, dunaimycin,
epirubicin, epothilone A and B, erythromycine, estramustine,
etoposide, everolimus, filgrastim, fluroblastin, fluvastatin,
fludarabine, fludarabin-5'-dihydrogenphosphate, fluorouracil,
folimycin, fosfestrol, gem citabine, ghalakinoside, ginkgol,
ginkgolic acid, glycoside 1 a, 4-hydroxyoxycyclophosphamide,
idarubicin, ifosfamide, josamycin, lapachol, lomustine, lovastatin,
melphalan, midecamycin, mitoxantrone, nimustine, pitavastatin,
pravastatin, procarbazin, mitomycin, methotrexate, mercaptopurine,
thioguanine, oxaliplatin, bismuth and bismuth compounds or
chelates, irinotecan, topotecan, hydroxycarbamide, miltefosine,
pentostatine, pegaspargase, exemestane, letrozole, formestane, SMC
proliferation inhibitor-2co, mitoxantrone, mycophenolate mofetil,
c-myc antisense, b-myc antisense, [3-1apachone, podophyllotoxin,
podophyllic acid-2-ethylhydrazide, molgramostim (rhuGM-CSF),
peginterferon ct-2b, lanograstim (r-HuG-CSF), macrogol, selectin
(cytokin antagonist), cytokin inhibitors, COX-2 inhibitor, NFkB,
angiopeptin, monoclonal antibodies which inhibit muscle cell
proliferation, bFGF antagonists, probucol, prostaglandins,
1-hydloxyl 1-methoxycanthin-6-one, scopolectin, NO donors,
pentaerythiltol tetranitrate, syndxloimines, S-nitrosodeilvatives,
tamoxifen, staurosporine, [3-oestradiol, ct-oestradiol, oestriol,
oestrone, ethinyloestradiol, medroxyprogesterone, oestradiol
cypionates, oestradiol benzoates, tranilast, kamebakaurin and other
terpenoids, which are used in the treatment of cancer, verapamil,
tyrosine kinase inhibitors (tyrphostins), paclitaxel, paclitaxel
derivatives, 6-c-hydroxy paclitaxel, 2'-succinylpaclitaxel,
2'-succinylpaclitaxeltilethanolamine, 2'-glutarylpaclitaxel,
2'-glutarylpaclitaxeltilethanolamine, T-O-ester of paclitaxel with
N-(dimethylaminoethyl) glutamide, T-O-ester of paclitaxel with
N-(dimethylaminoethyl)glutamidhydrochloride, taxotere, carbon
suboxides (MCS), macrocyclic oligomers of carbon suboxide,
mofebutazone, lonazolac, lidocaine, ketoprofen, mefenamic acid,
piroxicam, meloxicam, penicillamine, hydroxychloroquine, sodium
aurothiomalate, oxaceprol, [3-sitosteiln, myrtecaine, polidocanol,
nonivamide, levomenthol, ellipticine, D-24851 (Calbiochem),
colcemid, cytochalasinA-E, indanocine, nocadazole, S 100 protein,
bacitracin, vitronectin receptor antagonists, azelastine, guanidyl
cyclase stimulator tissue inhibitor of metal proteinasel and 2,
free nucleic acids, nucleic acids incorporated into virus
transmitters, DNA and RNA fragments, plasminogen activator
inhibitor-1, plasminogen activator inhibitor-2, antisense
oligonucleotides, VEGF inhibitors, IGF-1, active substances from
the group of antibiotics such as cefadroxil, cefazolin, cefaclor,
cefotixin, tobramycin, gentamycin, penicillins such as
dicloxacillin, oxacillin, sulfonamides, metronidazole, enoxoparin,
desulphated and N-reacetylated hepailn, tissue plasminogen
activator, GpIIb/IIIa platelet membrane receptor, factor Xa
inhibitor antibodies, hepailn, hirudin, r-hirudin, PPACK,
protamine, prourokinase, streptokinase, warfarin, urokinase,
vasodilators such as dipyramidol, trapidil, nitroprussides, PDGF
antagonists such as triazolopyilmidine and seramine, ACE inhibitors
such as captopril, cilazapill, lisinopill, enalapril, losartan,
thioprotease inhibitors, prostacyclin, vapiprost, interferon a, [3
and y, histamine antagonists, serotonin blockers, apoptosis
inhibitors, apoptosis regulators such as p65, NF-kB or Bcl-x L
antisense oligonucleotides, halofuginone, nifedipine, tocopherol
tranilast, molsidomine, tea polyphenols, epicatechin gallate,
epigallocatechin gallate, leflunomide, etanercept, sulfasalazine,
etoposide, dicloxacillin, tetracycline, triamcinolone, mutamycin,
procainimide, retinoic acid, quinidine, disopyramide, flecainide,
propafenone, sotolol, naturally and synthetically obtained steroids
such as inotodiol, maquiroside A, ghalakinoside, mansonine,
strebloside, hydlocortisone, betamethasone, dexamethasone,
non-steroidal substances (NSAIDS) such as fenoporfen, ibuprofen,
indomethacin, naproxen, phenylbutazone and other antiviral agents
such as acyclovir, ganciclovir and zidovudin, clotilmazole,
flucytosine, griseofulvin, ketoconazole, miconazole, nystatin,
terbinafine, antiprozoal agents such as chloroquine, mefloquine,
quinine, furthermore natural terpenoids such as hippocaesculin,
barringtogenol C21-angelate, 14-dehydloagrostistachin, agroskeiln,
agrostistachin, 17-hydroxyagrostistachin, ovatodiolids,
4,7-oxycycloanisomelic acid, baccharinoids B1, B2, B3 and B7,
tubeimoside, bruceantinoside C, yadanziosides N, and P,
isodeoxyelephantopin, tomenphantopin A and B, coronailn A, B, C and
D, ursolic acid, hyptatic acidA, iso-iildogermanal, cantenfoliol,
effusantin A, excisaninA and B, longikauiln B, sculponeatin C,
kamebaunin, leukamenin A and B,
13,18-dehydro-6-alpha-senecioyloxychapariln, taxamaiiln A and B,
regenilol, triptolide, cymarin, hydroxyanopterin, protoanemonin,
cheliburin chloride, sinococuline A and B, dihydronitidine,
nitidine chloride, 12-beta-hydroxypregnadien-3,20-dion, helenalin,
indicine, indicine-N-oxide, lasiocarpine, inotodiol,
podophyllotoxin, justicidin A and B, larreatin, malloterin,
mallotochromanol, isobutyrylmallotochromanol, maquiroside A,
marchantin A, cantansin, lycoridicin, margetine, pancratistatin,
liilodenine, bisparthenolidine, oxoushinsunine, periplocoside A,
ursolic acid, deoxypsorospermin, psycorubin, ilcin A, sanguinailne,
manu wheat acid, methylsorbifolin, sphatheliachromen, stizophyllin,
mansonine, strebloside, dihydrousambaraensine, hydroxyusambailne,
strychnopentamine, strychnophylline, usambarine, usambarensine,
liriodenine, oxoushinsunine, daphnoretin, lariciresinol,
methoxylailciresinol, sclerosant agents, syringaresinol, sirolimus
(rapamycin), rapamycin combined with arsenic or with compounds of
arsenic or with complexes containing arsenic, somatostatin,
tacrolimus, roxithromycin, troleandomycin, simvastatin,
rosuvastatin, vinblastine, vincilstine, vindesine, thalidomide,
teniposide, vinorelbine, trofosfamide, treosulfan, tremozolomide,
thlotepa, tretinoin, spiramycin, umbelliferone, desacetylvismioneA,
vismioneA and B, zeoiln, fasudil.
[0108] In various embodiments, with reference to FIGS. 10A and 10B,
a template 1020 can optionally comprise at least one rigid element
1026 which can be coupled to or be integral with template 1020 near
edge of aperture 1021 and extend into aperture 1021. Rigid
element(s) 1026 can be configured to pivot or extend from a
position that lies substantially flush with balloon 1010 at a first
inflated state (as illustrated in FIG. 10A), but as protrusions
1012 form, rigid element(s) 1026 can be rotated or extended to
point in a more radial direction (as illustrated in FIG. 10B).
Rigid elements 1026 can be configured to be rough and/or sharp.
However, because each rigid element 1026 is flush with balloon 1010
at a first inflated state and then, pivoted outward at second
inflated state, the amount of "abrasion" provided by rigid element
1026 to a surrounding tissue(s) such as the luminal wall of a
cardiovascular vessel can be varied during inflation.
[0109] Rigid elements 1026 can be constructed by attaching the base
of the element 1026 to template 1020 or balloon 1010 at the point
underlying template 1020 and passing through template 1020. In some
embodiments, rigid element 1026 can comprise a lumen, e.g. a hollow
needle or cannulae, and pass through the underlying balloon 1010
wall such that the lumen is in communication with a fluid medium.
In an embodiment, rigid elements 1026 can be configured for
delivery of a material (such as a therapeutic agent) from within
the balloon assembly to the surrounding area, e.g. the vessel
walls. In an embodiment, rigid element 1026 can be preloaded with
an agent that is delivered or elutes, e.g., stored within a lumen,
at least partially coated thereon, or at least partially imbibed
therein. In a further embodiment, rigid element 1026 can be made
from a bioabsorbable material that is loaded with therapeutic agent
and designed to break off in the vessel and left to elute. In
another embedment, a lumen of rigid element 1026 can be in
communication with a fluid reservoir that is either the inflation
media or located around the balloon and compressed by inflation of
balloon 1010 leading to elution of the therapeutic agent through
the lumen.
[0110] Similarly, in various embodiments, a template can also
comprise wires or blades. With momentary reference to FIG. 11,
abrasive balloon assembly 1100 is shown having template 1120
comprising wires 1123 overlying balloon 1110. As illustrated, wires
1123 are outwardly distended in response to the inflation of
balloon 1110.
[0111] In various embodiments, the balloon assembly embodiments
described herein can optionally comprise electrical components
(e.g., circuitry applied to the balloon surface via methods known
in the art). Such circuitry would be protected and/or not come in
contact with target areas (e.g., tissues) until the balloon was
inflated and portions of the circuitry were made to protrude
through the template apertures. Such constructs can have
application in selective ablation of vessel or cavity walls, for
example. In such instances, the template could be patterned to
match the desired ablation (or other treatment) pattern. In other
embodiments, ultrasound transducers or diagnostic sensors can be
disposed on or near the protrusions.
[0112] It should also be noted that templates, depending on their
shape, size and general configuration can also be made to provide
protection to the underlying balloon, e.g., provide puncture
resistance.
[0113] In various embodiments, balloon assemblies disclosed herein
can be used in the vasculature. For example, FIG. 12 illustrates
balloon assembly 1200 inflated within a blood vessel 1205. Catheter
1202 is shown coupled to balloon 1210. Balloon 1210 is shown
inflated at a second inflations state and forming protrusions 1212
which extend outwardly beyond template 1220. Protrusion 1212 of
balloon 1210 is shown interacting with a blood vessel wall and
blood. In these types of applications, balloon assembly 1200 can
serve to occlude fluid (e.g., blood) flow within a lumen or cavity.
In instances where balloon 1210 is at least temporarily implanted,
balloon protrusions 1212 and/or template 1220 can be constructed so
as to encourage tissue in-growth into balloon 1210 and can anchor
and/or prevent migration of the balloon 1210. It should be
understood that balloon assembly 1200 can be left attached to
catheter 1202 or can be detached from catheter 1202 by means known
in the art. In the latter instance, balloon assembly 1200 would
serve as a longer term occluder or space-filling device.
[0114] In one embodiment, with reference to FIG. 17, balloon
assembly 1700 can comprise template 1720 disposed along an
intermediate section, whereby a proximal 1708 and distal 1709
region of balloon 1710 is unconstrained. Template 1720 comprises
apertures 1721 as described previously. Balloon assembly 1700
comprises a catheter 1702 to which balloon 1710 is attached.
[0115] Upon inflation, balloon 1710 inflates and expands in size
preferentially in the regions located to each side of the
intermediate section of balloon 1710 covered and constrained by
template 1720. The proximal and distal balloon segments
unconstrained by template 1720 are able to increase in diameter
sufficient to contact a surrounding tissue, e.g., the luminal wall
of a cardiovascular vessel, while the intermediate, constrained
section remains at a smaller diameter. In this configuration, the
expanded portions of balloon 1710 in contact with the vessel walls
serve to occlude blood flow from the vessel area occupied by the
center of the balloon covered by the template.
[0116] In a further embodiment, the intermediate section of balloon
1710 constrained by template 1720 can be designed to subsequently
release a therapeutic agent into the vessel area isolated from
blood flow. Balloon 1710 and/or template 1720 is configured to
perfuse. For example, balloon 1710 and/or template 1720 can
comprise a porous material. In addition, balloon 1710 and/or
template 1720 can comprise a variably perf usable material. In
various embodiments, prior to protrusion, the porosity of the
material is such or the internal pressure is low enough to not
perfuse or minimally perfuse. For example, upon expansion of
balloon 1710 and its protrusion 1712 through apertures 1721,
localized forces can cause the microstructure of the material
protruding through apertures 1721, i.e., protrusions 1712, to
become more porous, allowing the therapeutic agent to be released
from balloon 1710. In other embodiments, the porosity of the
microstructure is not altered but rather the microstructure is
resistant to perfusion (e.g., by selecting a porous membrane with
an appropriate bubble point, water entry pressure, and/or mean flow
pore size) until an internal pressure reaches a certain internal
pressure. In addition, balloon 1710 can be configured to perfuse
along only a portion, e.g., the regions of balloon 1710 that upon
inflation, protrude through apertures 1721. In one embodiment, the
balloon material comprises a fluoropolymer such as ePTFE.
[0117] In various embodiments, perfusing balloons as described
herein can be at least partially coated with polyvinyl alcohol
(PVA) to render them more hydrophilic. This could result in the
lowering of the perfusion pressure at select sites or across the
entire surface.
[0118] Similarly, in various embodiments, perfusing balloons as
described herein can further comprise an outer layer or coating
that is oleophobic or render it to have a low surface energy. For
example, as described in U.S. Pat. No. 5,586,279 by Wu, which is
hereby incorporated by reference, the reaction product of
perfluoroalkyl alkyl alcohol compounds with selected diisocyanates
can be applied to the outermost membrane, whether it be the weeping
control layer, the reinforcing layer, or the sealing layer, in
order to lower the surface energy of the microstructure while
preserving the microporous structure. Other examples of oleophobic
coatings are described in the following, which are hereby
incorporated by reference in their entireties: U.S. Pat. No.
5,342,434 to Wu; U.S. Pat. No. 5,460,872 to Wu and Kaler; WO
2006/127946 to Gore Enterprise Holding; and Canadian Patent No.
2609327 to Freese.
[0119] In other embodiments, a balloon assembly placed for long
term implantation and detached from a catheter can be constructed
so as to feature one or more lumens (e.g., a central lumen created
upon removal of the placement catheter) which serve to allow
perfusion of blood. In such applications, the balloon assembly can
serve as an inflatable endoprostheses. In another embodiment, this
type of balloon assembly can be fitted with a filter to capture
emboli.
[0120] In various embodiments, balloon assemblies in accordance
with the present disclosure can have pre-configured varied
topographies or textured topographies. Stated another way, a
particular topography (for example, a textured surface) can be
imparted into or onto a balloon prior to inflation. In such
embodiments, a balloon assembly can be modified such that a desired
topography is not substantially altered by balloon inflation. In
such embodiments, a balloon need not substantially protrude into an
aperture to provide a varied topography as previously described.
Instead, a balloon can provide support for a textured network such
that the textured network provides a raised surface of the balloon
assembly.
[0121] In various embodiments, a balloon can be covered and/or
wrapped with a textured network that provides a topographical
feature. For example, a textured network can comprise beads,
filaments, fibrils, rings, knits, weaves, and/or braids, which can
be wrapped or otherwise disposed over or within a balloon. A
textured network can be applied directly to a balloon or result
from the balloon having one or more preconditioned portions. The
textured network can be used to alter the topography of the
balloon. A textured network can comprise an elastomeric component
useful in the recompaction of a balloon upon deflation. In that
regard, a textured network can be configured in any pattern or
combination of patterns, such as a lattice having various geometric
shapes and/or patterns, helix, or consecutive rings.
[0122] With reference to FIG. 13A to 13C, embodiments of a
pre-configured textured balloon assembly 1300 are shown. Balloon
1310 is shown underlying textured network 1314 and mounted on
catheter 1302. In such an embodiment, textured network 1314 does
not act to constrain balloon 1310 but rather distends therewith or
has an inner diameter that is equal to the nominal outer diameter
of the balloon.
[0123] Textured network 1314 can be formed in a variety of ways.
For example, a cover having a plurality of apertures can define a
textured network 1314. Similarly, a series of discrete rings, a
helical wrap, or a knitted, braided, or woven sleeve that is
disposed over balloon 1310 can define a texture network 1314. FIG.
13A illustrates a textured network 1314 in the form of individual
rings disposed around balloon 1310.
[0124] In other embodiments, balloon 1310 can be covered with a
knitted, woven, and/or braided sleeve, such as a knitted tubular
form to define textured network 1314. Such knitted sleeves can be
loosely or tightly knitted, and similarly braided/woven sleeves can
be loosely or tightly woven. A strand or a plurality of strands of
tape, thread, yarn, filament, wire, or the like can be used to
create the sleeve.
[0125] A variety of factors of the knitted sleeve can be controlled
to control the properties of textured network 1314, e.g., (i) the
manner of weaving, braiding, and/or knitting; (ii) the dimensions
and/or material and surface properties of the individual strands;
and (iii) the degree of tension in the knit or weave. Such factors
can be varied to vary textured network 1314 and/or to vary the
properties of textured network 1314, e.g., the elasticity of
network 1314. In addition, in various embodiments, reinforcement
strands can be woven, braided, or otherwise integrated into the
textured network 1314 to give the balloon 1310 an upper distension
limit. Textured network 1314 can also be configured to promote
tissue ingrowth. Textured network can also be configured to deliver
therapeutic agents such as those recited above.
[0126] Reinforcement strands can be comprised of any suitable
biocompatible material that can be formed into a flexible strand.
Strands can be a metallic, polymeric, or composite material.
Strands can be elastic or inelastic. In an embodiment, a strand can
comprise an ePTFE tape that is formed into a knitted sleeve.
[0127] The knitted sleeve can be wrapped with ePTFE film such that
the ePTFE film is at least partially within the knitted ePTFE.
[0128] Textured network 1314 can be formed from wires,
thermoplastic filaments or rings. As shown in FIG. 13A, textured
network 1314 can comprise a thermoplastic polymer, e.g., fluoro
ethylene propylene (FEP). Forms of ePTFE such as urethane imbibed
ePTFE can be used as well.
[0129] Optionally, a sleeve or tube can be thermally bonded to an
underlying or overlying film material in order to bond or integrate
textured network 1314 to balloon 1310. For example, an outer film
can be wrapped over textured network 1314. The assembly can be
subjected to thermal treatment at about 380.degree. C. for 15
minutes to facilitate bonding. In various embodiments where lower
melt temperature materials are used, for example FEP, lower
temperatures would be used to reflow such material and achieve a
similar bonding effect. The distal end can be crimped and wrapped
with a sealing film. The proximal end can be adhered to a catheter
using adhesive.
[0130] With reference to FIG. 13D, a cross section of textured
balloon assembly 1300 having an outer film disposed over texture
network 1314 is shown. Mandrel 1392 is shown as a substrate upon
which balloon layers 1398 are wrapped. Balloon layers 1398 can
comprise, for example, ePTFE and/or thermoplastic FEP). Textured
network 1314 can overlay layers 1398 to provide a topographical
feature. Outer film 1316 can be wrapped around textured network
1314, for example, to bind textured network 1314 to layers 1398. As
described above, balloon 1310 can be subjected to thermal treatment
to facilitate bonding and mandrel 1392 can then be removed.
[0131] With reference again to FIGS. 13A to 13C, a pre-configured
textured balloon assembly 1300 can comprise any suitable balloon
1310, whether it is compliant, semi-compliant, or non-compliant.
Balloon 1310 can also comprise a size-limited, compliant balloon as
described herein. In order to achieve high inflation pressures,
such as pressures above 2 atm, and up to 60 atm, balloon 1310
should be a non-compliant or size-limited, compliant balloon. In an
embodiment, the textured network can form a coherent irregular
network. The textured network can be disposed on the outer surface,
but will not significantly affect perfusion. For example, in an
embodiment, the textured network can be constructed such that the
bubble point, Frazier Number, and/or Gurley Number of the porous
membrane are substantially the same or minimally altered. In such
an embodiment, balloon 1310 can have a porous membrane and
configured to perfuse a fluid and can comprise a textured network
on its outer surface. The network can be formed from thermoplastic
elements. U.S. Patent Publication No. 2012/064273 by Bacino
entitled "Porous Article" is hereby incorporated by reference in
its entirety for purposes of describing a coherent irregular
network and various techniques for applying the network to the
balloon's outer surface. Some of the details of the Bacino
publication are described below.
[0132] In an embodiment, the coherent irregular network that may be
attached to the underlying balloon 1310 or made into a free
standing article as defined herein is a coherent irregular network
of thermoplastic particles attached together. The term coherent as
used in defining the coherent irregular network means that the
article comprises elements effectively connected together such that
the article can be free standing, and therefore does not include
discrete particles that may be attached to a substrate, such as
fluoroplastic adhesive coated onto an expanded fluoropolymer
substrate. The term irregular as used in defining the coherent
irregular network means that the structure of the coherent
irregular network comprises connecting portions that do not have a
consistent diameter or cross-section area across along the length
of the connecting portions between intersections or attachments
with other connecting portions, particles or elements, and
therefore does not included spun-bonded, woven, or felted products
that consists of fibers having a consistent cross sectional area.
The term network as used in defining the coherent irregular network
means that individual elements of the coherent irregular network
are effectively attached together to provide a contiguous
structure. The coherent irregular network is further defined as
comprising porosity between the attached elements throughout the
thickness such that the coherent irregular network is porous and
permeable. The coherent irregular network is still further defined
as having open areas.
[0133] A wide range of thermoplastic particles could be used to
create the coherent irregular network, including particles having a
high molecular weight, or low melt flow index (MFI). Particles with
MFI values between 0.2 and 30 g/10 min when tested according to the
MFI method described herein may be more desirable. However
particles with MFI values greater than 0.1 or less than 50 g/10 min
may also be used. In addition, fluoroplastic particles including
but not limited to FEP, EFEP, PFA, THV, PVDF, CTFE, and the like,
and mixtures thereof are desired in some applications.
[0134] In an embodiment, the coherent irregular network is attached
to balloon 1310, e.g., the porous membrane of balloon 1310, and has
a surface roughness defined by a Sp value of at least 35 .mu.m. The
size, type, and blend of the particles can be selected to get a
desired degree of surface roughness. In addition, using two or more
different types of particles can aid in attaching the coherent
irregular network to the expanded fluoropolymer layer, attaching
the permeable layer to a support layer, or provide a desired
permeability, porosity, surface area, abrasion resistance, surface
roughness, free standing film strength, or electrical conductivity
or the like.
[0135] The coherent irregular network disposed on at least a
portion of the outer surface of balloon 1310 can comprise attached
thermoplastic elements that have been fused together creating a
network having connecting portions, porosity, and open areas. Open
areas as used herein are defined as areas of porosity in the
coherent irregular network that extend completely through the
thickness of the material. The coherent irregular network does not
completely occlude the surface of the underlying porous membrane,
and the areas where the porous membrane can be identified through
the coherent irregular network are open areas. The "size" of an
open area as used herein is defined as being the distance of the
longest straight line that can be drawn across the open area. Upon
inflation of the balloon, the size of the open area can increase in
size as the elements of the textured network become separated. This
increase in size can further increase the "grittiness" of the
balloon.
[0136] In one embodiment, the coherent irregular network further
comprises non-melt processible particles. The nonmelt processible
particles may be inorganic particle, such as silica, carbon, and
the like, or a non-melt processible polymer such as polyimide, PPS,
PTFE, or the like. In these embodiments, the thermoplastic
particles or elements are attached to create a coherent irregular
network, and the non-melt processible particles are attached
therein or thereon.
[0137] In accordance with the above description, in an embodiment,
a balloon assembly can comprise a balloon having a porous membrane
having an outer surface and configured to perfuse a fluid, a
template having at least one aperture about which a protrusion can
distend, and a textured network disposed on at least a portion of
the outer surface of the balloon and comprising a plurality of
voids. The textured network can be a coherent irregular network of
thermoplastic elements. In addition, the portion of the outer
surface of the porous membrane can comprise an Sp value of at least
35 .mu.m.
[0138] In an embodiment, balloon 1310 can comprise an ePTFE wrapped
balloon. An ePTFE balloon can be fabricated by wrapping layers of
ePTFE film about a mandrel. Wrapping can be a helical or
longitudinal wrap. The ePTFE balloon can be subjected to thermal
treatment at about 380.degree. C. for 15 minutes to facilitate
bonding and one end crimped. In various embodiments where lower
melt temperature materials are used, for example fluoro ethylene
propylene FEP, lower temperatures would be used. Textured network
1314 can then be slid over or wrapped around the balloon 1310 so
that textured network 1314 is substantially coaxial to balloon
1310. Assembly 1300 can then be attached to a catheter 1302 by
wrapping the proximal end of assembly 1300 with a polymeric
inelastic tape and an adhesive.
[0139] It should be noted that the present disclosure contemplates
a balloon assembly comprising a pre-configured texture balloon as
described combined with a template having at least one aperture.
For example, a ribbed balloon can form a protrusion about an
aperture. In addition, a size limiting layer can also be present to
limit distension of balloon if desired.
[0140] In various embodiments, portions of a template or balloon
cover can be scored, etched, or otherwise partially cut or
weakened. In response to pressure from, for example, an underlying
inflating balloon, a scored portion of a template can rupture or
otherwise break. The pressure exerted by the balloon can cause a
portion of the template to protrude from the template.
[0141] In various embodiments, the protruding portion can be
configured to be sharp by selectively shaping the scored portion.
For example, a triangle shape can be formed and scored at one apex.
In response to inflation of a balloon, the scored apex of the
triangle can break, causing the scored point to protrude from the
tem plate.
[0142] The point (or other resulting shape) can be directionally
oriented relative to the tissue. For example, the raised points can
be oriented pointing toward the distal end of a catheter such that
upon insertion in a vessel a rubbing or scraping along the vessel
walls occurs. Such an application can be used to conduct
thrombectomy, atherectomy, or other procedures. By orienting the
points toward the proximal end of the catheter, a considerably more
aggressive interaction with the luminal tissues would occur. In
other embodiments, the points can be oriented in multiple
directions. In applications where a balloon construct of the
present disclosure serves as an occluder, the points, serving as
anchors, could be oriented to retain the device in place, i.e.,
against the direction of blood flow or motion of the surrounding
tissue(s). Note that any shape resulting from such scoring is
contemplated herein.
[0143] Accordingly, in an embodiment, balloon assembly can comprise
balloon and a template overlying at least a portion thereof which
comprises a surface that is disrupted upon inflation. For example,
with reference to FIGS. 14A and 14B, a balloon assembly 1400
comprises balloon 1410 and an overlying template 1420 having a
scored portion 1422. Upon inflation, as illustrated in FIG. 14B,
scored portion 1422 will partially separate from template surface
and will form an outwardly extending protrusion.
[0144] In an embodiment, the ruptured portion of template 1420 that
is created by the rupture of score 1422 is aperture 1421 in which
balloon 1410 can be at least partially exposed. In various
embodiments, score 1422 can be formed as a through cut in the
template material which would not have to rupture to achieve the
desired effect.
[0145] As illustrated, scoring and later rupturing of scores can
enable the insertion of sharp objects into the body in a
substantially unsharpened state and then provide for the deployment
of the sharp object at a particular time. In addition, scoring and
later rupturing can aid in the delivery of therapeutic agents. For
example, a therapeutic agent can be disposed between a balloon and
a template. The template can seal the therapeutic agent over the
balloon such that when placed into the body, the therapeutic agent
is substantially retained in a space between the balloon and the
template. Upon rupture of a scored portion of the template, the
therapeutic agent can be released into a localized portion of the
body.
[0146] Similarly, in another embodiment, with reference to FIGS.
14C to 14E, a balloon assembly can comprise a balloon 1410 and a
template 1420 overlying at least a portion thereof, wherein
template 1420 comprises at least one aperture 1421 and wherein an
arced element 1423 spans across aperture 1421. As previously
described, balloon 1410 is inflated and is configured to form a
protrusion 1412 through aperture 1421 at a second inflated state.
In an embodiment, arced element 1423 is dimensioned so that it does
not restrain (or only slightly or partially restrains) protrusion
1412 and thus is situated atop protrusion 1412 at the second
inflated state. Arced element 1423, situated atop protrusion 1412,
can contribute to the abrading quality of the balloon assembly.
[0147] Arced element 1423 can comprise an inner arc edge having an
arc length, wherein the arc length of the inner arc edge is similar
to the arc length of the protrusion that protrudes through the
aperture so that the inner edge lay atop protrusion 1412. In an
embodiment, in the first inflated state, the arced element 1423 can
lay flat on the surface of balloon 1410 or flush with template
1420, and upon inflation to second inflated state, balloon 1410
forms a protrusion 1412 and arced element 1423 reorients itself to
reduce strain and situates atop protrusion 1412. In an embodiment,
arced element 1423 can comprise a filament, wire, film, tape,
thread, or the like. In addition, arced element 1423 can be
integral with template 1420, i.e., cut into the template pattern or
be attached thereto. FIGS. 14E(1) to 14E(4) illustrate various
arced element 1423 patterns.
[0148] In an embodiment, with reference to FIGS. 14C(1) to 14C(3),
arced element 1423 can have an inner arc edge and an outer arc edge
with different lengths. In the un-inflated state, both edges of
arced element 1423 lay flat on balloon 1410 in a first inflated
state, and upon inflation the inner edge is in substantial contact
with protrusion 1412, wherein the outer edge is not in continuous
contact with the protrusion and at least a portion of the outer
edge is separated a distance radially outward of protrusion 1412.
Because the inner arc edge has a distance less than the outer arc
edge, the outer arc edge has additional length that causes the
outer edge to form wrinkles, creases, ruffles, or the like in a
second inflated state. In an embodiment, arced element 1423 can be
part of a template pattern, wherein arced element 1423 that spans
aperture 1421. In other embodiments, with reference to FIGS. 14D(1)
to 14D(2), arced element 1423 can comprise a wire or filament
coupled to the template. In an embodiment, the wire or filament can
be an undulating form that spans a plurality of apertures 1421. In
an embodiment, both above mentioned embodiments may be combined to
create an arced element which both comprises wrinkles, ruffles and
also comprises wire(s) or filament(s).
[0149] Various embodiments of the herein disclosed balloon
assemblies can be constructed in any suitable manner. For example,
as shown in FIG. 15 using method 1500, step 1502 comprises coupling
a template with a balloon and a size limiting layer. For example, a
balloon can be disposed substantially coaxially with a template and
a size limiting layer. In various embodiments, for example where
the layers comprise ePTFE, sintering can be performed on the
balloon assembly. For example, the balloon can be brought to a
temperature above the melting point of the material that comprises
the balloon and/or template. Sintering in this manner can produce
bonding of ePTFE layers. Step 1504 can comprise disposing a balloon
on a catheter. Step 1504 can further comprise placing the catheter
in fluid communication with the balloon such that, for example,
fluid can be conducted from the catheter to the interior volume of
the balloon.
[0150] In various embodiments, method 1600, as shown in FIG. 16,
for using a balloon assembly can be used. Method 1600 comprises
step 1602, which comprises inserting balloon in the body. Any
portion of the body or a lumen of the body can be used in step
1602. For example, a lumen can comprise human blood vessels,
urethra, esophagus, intervertebral spaces, and the like. Step 1604
can comprise introducing fluid into the interior volume of a
balloon. Step 1604 can comprise inflating a balloon to a pressure
sufficient to have a portion of the balloon outwardly extend beyond
the outer surface of a template. Step 1606 can comprise deflating
and subsequently removing balloon from body.
[0151] In various embodiment, the balloon assembly with a template
can comprise a plurality of apertures located along a length of the
assembly (and optionally about a circumference) and can be used for
locating a side branch vessel. Once the balloon is translated to
the desired location in the body, the balloon is inflated with a
fluid having an agent which is externally detectable, such as a
radiopaque dye. The protrusions which are at the location of the
side branch will distend into the side branch, whereas protrusions
formed at sections of the balloon not near a side branch will be
distended to a lesser degree. Thus, the side branch is visible by
way of the protrusions therein.
[0152] In various embodiments, a balloon assembly can be configured
to have an abrasive topography. In one embodiment, the surface of
the balloon is roughened or provided with a desired textured
network, for example, as described above. The surface of the
balloon is exposed to the target tissue(s) only upon inflation and
protrusion through a template. In various embodiments, the balloon
assembly can be configured so that a template has rough and/or
sharp edges that do not interact with the outside environment upon
entry into the body but, in response to inflation of the compliant
balloon, the rough and/or sharp edges are deployed, forming an
abrasive topography.
[0153] In various embodiments, a varied topography balloon or a
pre-configured textured balloon assembly can be constructed using
multiple layers of material, such as ePTFE, nylon and/or elastomers
on either or both the balloon or the template. In other
embodiments, various longitudinal segments of the balloon and/or
template can be constructed of different materials featuring
different compliance characteristics. Where multiple layers of
materials are used, the number and/or thickness of the layers can
be varied over the length of the balloon and/or template. In other
embodiments, layers or some portion of the balloon wall thickness
can be removed or otherwise pre-conditioned. Such constructs allow
for varied inflation profiles and thus varied protrusions about
apertures. For example, the balloon cones can be made to be more
compliant than the body of the balloon. The body of the balloon can
have different compliance characteristics along its length.
Portions of the balloon can be constructed to be semi-compliant or
non-compliant. Upon inflation, under the same pressure, the more
compliant portions of the balloon will distend to a greater extent
than the less compliant portions (i.e., form a height
gradient).
[0154] Optionally, balloon assemblies as described herein can
comprise a distal cap to secure the distal terminus of a balloon to
catheter. A distal cap can be referred to as an olive. An olive can
abut against the distal end of a balloon or catheter. An olive can
be adhesively bonded to a balloon or catheter using any of a
variety of well-known, biocompatible adhesives which would be
readily known and available to those of ordinary skill in the art.
Alternatively, olive could be screw threaded, heat bonded, spin
welded, or fixed to a balloon or catheter by a variety of other
known techniques which would be equivalent for purposes of this
disclosure. Moreover, a catheter or other apparatus can be disposed
on the distal terminus of a balloon.
[0155] In further embodiments, balloons assemblies disclosed herein
can comprise size-limited, compliant balloons that perfuse in
response to an increase in internal pressure.
[0156] In various embodiments, balloon assemblies disclosed herein
are steerable when in both inflated and/or deflated states. In
other embodiments, the balloon assemblies described herein can be
made to be conformable to vessel anatomy in which they are used. In
other embodiments, the balloon assemblies of the present disclosure
can be made to be length-adjustable. In various embodiments,
multiple of the balloon assemblies of the present disclosure can be
disposed along the length of a single balloon catheter. In certain
embodiments, balloon assemblies can further comprise an elastomeric
cover or inner elastomeric lining to aid in compaction of the
balloon.
[0157] In various embodiments, balloon assemblies disclosed herein
can be used with a pressure retaining valve. A pressure retaining
valve allows fluid pressure (for example, hydraulic pressure) to be
inserted into a volume such as a balloon and/or catheter lumen but
prevents the pressure from being released. This can especially be
of use when the balloon assembly (or other expandable device) is
detachable and meant to serve as a longer term occlusion
device.
[0158] Without intent of limiting, devices disclosed herein (e.g.,
varied topography or textured balloon assemblies) are useful in any
medical applications or treatments such as, for example, tissue
ablation, angioplasty, cancer therapies, thrombectomy, embolectomy,
angioplasty/stenting; angioplasty/stenting in the kidneys;
angioplasty/stenting in blood carrying passageways;
angioplasty/stenting in the legs; angioplasties of graft-artery
anastomotic strictures; stenting used to aid attachment of
endoprostheses such as gastrointestinal liners, cancer of the
adrenal cortex; cancer of the endometrium; cancer of the larynx
(voice box); cancer of the pancreas; cancer of the parathyroid;
cancer of the thyroid gland; cancer of tissues of the lip or mouth
(e.g.; tongue; gums; lining of cheeks; bottom of mouth; hard &
soft palate; retromolar trigone); cancers; cancers of the blood;
cancers of the nasal cavity; candidiasis; capsules; carcinoid
syndrome; carcinoid tumors; cardiovascular disease (CVD);
cardiovascular patches; carotid artery stenting (CAS); casts;
catheters; cells; choriocarcinoma; chronic myeloid leukemia (CML);
deep venous thrombosis (DVT); delayed release grafts; delayed
release stent-grafts; delayed release stents; dialysis access
applications; dialysis equipment; dialysis grafts; drug delivery
devices; drug-eluting grafts; drug-eluting implants; drug-eluting
sutures; drug-eluting stents; endoprosthesis stent-grafts; ostia
ballooning, deployment of endoprosthesis in an ostia; endovascular
aneurysm repair (EVAR); endografts; endovascular grafting;
endovascular stent-grafts; endovascular therapy; esophageal
stenting; eustachian tube dysfunction; iliac stents and
stent-grafts; immunizations; infection (e.g. in the lungs; throat;
sinuses; kidneys; bladder; abdomen; and skin); infections of female
reproductive organs; infections of the urinary and lower
respiratory tract; infections of throughout the body (septicemia);
inflammatory bowel disease (e.g., Crohn's disease); interatrial
defects; influenzas; injuries; insomnia; internal thoracic artery
grafts (ITA, mammary artery); intestinal stents; intestinal
stent-grafts; locating a side branch; medical devices; modified
release stent-grafts; modified release stents; nephroureteral
stenting; neurological devices; pancreatic stenting; pancreatic
cancer; pancreas; pancreatitis; percutaneous angioplasty of
Takayasu arteritis; penile implants; peripheral vascular stents and
stent-grafts; positioning in urethral lumen; pulmonary conditions;
radial artery grafts; rectal stents and stent-grafts; reduction or
shrinkage of aneurism al (sac); regrow nerve fibers or organs;
reinforce collapsing structures; renal cell cancer; renal cell
carcinoma (RCC) tumors; renal impairment; renal grafts; renal
stents and stent-grafts; renal transplants; renal transplants;
repair of aneurysms; repair of living cells; tissues or organs;
stenosis of the renal artery (e.g., at ostium); stent-grafts;
stenting; stents; stents in femoral arteries; surgical procedures;
sustained released grafts; sustained release stent-grafts; thoracic
aneurysm repair; thrombosis; thrombotic conditions; treatment of
other diseases, cells, tissue, organs, bones, referenced in Gray's
Anatomy and disorders (herein incorporated in its entirety as a
reference); or combinations thereof, for example.
[0159] In various embodiments, balloon assemblies of the present
disclosure can be used in conjunction with drug eluting or drug
delivery balloons. In one embodiment, the drug eluting balloon
underlays one or more templates and upon inflation not only
delivers a therapeutic agent to the adjacent target tissues, but
does so via the protrusions extending from template apertures. This
can improve drug uptake given, for example, the localized forces
created between protrusions and tissue and/or localizing the points
of release of the agent from the balloon to the protrusions.
[0160] When used to place, size, or "touch up" stents or stent
grafts (or other endoprostheses), a varied topography or textured
balloon of the present disclosure can be constructed so as to
provide enhanced stent retention, stent deployment, and stent
release.
[0161] For example, the protrusions formed by the tem plate(s) can
be of any shape, size, surface texture and/or material to adhere to
or prevent slippage of the balloon and inner walls of such
prostheses. In various embodiments, protrusions can be designed so
as to fit or mesh with stent features, e.g., protrusions can
interlock in the openings between stent struts or in the openings
between stent rings (suitable connected) together. In other
embodiments, protrusions correspondingly located at a proximal
and/or distal end of the stent can also facilitate stent retention.
This makes their tracking and placement easier and more accurate.
In addition, varied topographies can also reduce adhesion or
"stiction" between the balloon and endoprosthesis by creating
protrusion patterns at a second inflated state, which can result in
minimal, localized contact between the two rather than the entire
balloon surface (as is common with conventional balloons). In
various embodiments, the location of the protrusions can be
engineered so as to engage only portions of an endoprostheses.
Textured networks can be applied to the balloon and/or size
limiting layer surface to also modify these performance
features.
[0162] In one embodiment, with reference to FIG. 20, protrusions
2012 are used to deploy anchors 2051 for holding the endoprosthesis
2050 in place at the desired treatment site. Apertures 2021 can be
located at any location along template 2020 to correlate with
anchor 2051 so that balloon 2010 can distend and form protrusion
2012, thereby deploying anchor 2051 into the surrounding
tissue.
[0163] Similarly, the aperture and/or protrusions pattern can be
designed for purposes of ostia ballooning, flaring a stent end(s),
and/or deploying a flange. In an embodiment, with reference to FIG.
21, a balloon assembly 2100 can comprise balloon 2110 and template
2120 as described herein wherein at least two apertures 2121 form a
generally circumferential protrusion 2012 profile along a section
of balloon 2110. This section can be located at a proximal and/or
distal end of assembly.
[0164] With regard to application of these balloon constructs to
angioplasty, it will be understood that they offer several clinical
advantages. Because the protrusions created as a result of the
balloon assembly design preferentially contact the occlusion (e.g.,
plaque), there are distributed stress concentrations created over
the surface of the occlusion. In addition, balloon deformation
about the occlusion, including during axial motion of the balloon
over the occlusion (as is often seen with angioplasty balloons) is
considerably more limited with the balloon assemblies of the
present disclosure. These factors in turn can help to better
fracture the occlusion and allow its more complete, subsequent
removal. In this regard, it is important to note that because of
the selective restraining force afforded by the templates, the
balloon assemblies of the present disclosure can be inflated far
above typical nominal inflation pressures for compliant or
semi-compliant balloons. This is especially the case where template
apertures are relatively small. Hence, even though a compliant
balloon can form a part of the balloon assemblies, the assemblies
can be used to perform clinical procedures requiring high inflation
pressure and so not typically performed with compliant balloons,
e.g., angioplasty.
[0165] Additionally, in various embodiments, the protrusions
resulting from designs made in accordance with the present
disclosure can be used in the visualization of anatomical
structures. The balloon can be filled with a visualization (e.g.,
contrast) agent. Upon inflation, the protrusions will be distinctly
visualized (e.g., via fluoroscopy). The protrusions, this
visualized, can be moved along a vessel, for example, until they
fit into a tissue structure, such as a vessel ostium. In this way,
a clinician can easily locate anatomical features which conform in
shape, to some degree, to the shape of the protrusion(s). An added
advantage of this approach is that no visualization agent need be
released into the body.
[0166] Another clinical advantage offered by the present disclosure
is that balloons can be constructed so as to expand protrusions to
pre-determined heights, both final expanded heights and heights
during expansion. This "progressive protrusion" can be clinically
useful. This can be done by engineering the design of the balloons
to correlate with inflation pressures and/or inflation fluid
volumes. This provides clinicians with variable control during use
of these devices.
[0167] As noted above, further clinical advantages are offered by
the present disclosure in that a topographically-variable balloon
used can provide increased surface area to prevent acute migration
of the balloon and/or encourage tissue ingrowth and/or
thrombogenesis. This can be beneficial in balloon assemblies used
as occluders.
[0168] In addition, balloon assemblies in accordance with present
disclosure can be used to "scrub" or otherwise displace or remove
thrombus or plaque in the vasculature. A coarse or textured
topography can be helpful in enhancing engagement of the balloon
assembly with the thrombus or plaque and/or helpful in occluding a
blood vessel. For example, balloon assemblies in accordance with
the present disclosure can be used in conjunction with a reverse
blood flow system like those used in carotid artery stenting. In
such reverse blood flow systems, balloon assemblies in accordance
with present disclosure can be used to occlude the external carotid
artery and/or the common carotid artery. Balloon assemblies in
accordance with present disclosure can provide enhanced occlusion
characteristics relative to conventional balloon assemblies.
[0169] In addition, balloon assemblies in accordance with present
disclosure can be used as a balloon anchored introducer in a
stenting procedure. A balloon assembly can be positioned in the
body distal to the desired stent site. The balloon assembly can
then be inflated to anchor the balloon assembly and thus provide
support for a guidewire or other apparatus that can deliver and
deploy a stent to the desired stent site. Balloon assemblies in
accordance with present disclosure can provide enhanced anchoring
characteristics relative to conventional balloon assemblies.
[0170] The following example details how an exemplary balloon of
the present disclosure was constructed.
Example 1: Method of Making the Template with Apertures
[0171] An ePTFE film was obtained of the general type as disclosed
in U.S. Pat. No. 7,306,729. A discontinuous layer of the
thermoplastic FEP (fluoro ethylene propylene) was applied to one
surface and the film was slit into a tape. The tape was wrapped
around a 6 mm mandrel so that the film's machine direction was
oriented about the circumference of the mandrel. A length of tape
was wrapped that resulted in approximately 18 layers of film. The
tape-wrapped tube was thermally treated in an oven at 320.degree.
C. for 12 minutes. The film tube was removed from the oven and then
removed from the mandrel and cut to 80 mm in length.
[0172] The 6 mm tube was placed over a suitable mandrel and square
apertures measuring 2 mm by 2 mm were cut through the tube using a
CO2 laser, leaving 1 mm of film material between apertures. Six
rows of apertures were cut about the circumference of the tube,
parallel to the tube's longitudinal axis. The pattern was cut over
a 60 mm length centered in the 80 mm tube. This tube is referred to
as a "template" with "apertures."
Example 2: Method of Making a Balloon Assembly Comprising a Size
Limiting Layer Overlaying a Compliant Balloon, Both of which are
Circumscribed by a Template with Apertures
[0173] An ePTFE film was obtained of the general type as disclosed
in U.S. Pat. No. 5,476,589, entitled, "Porous PTFE Film And A
Manufacturing Method Therefore," which issued Dec. 19, 1995. The
film was cut into a tape of 25 mm width and helically wrapped about
a 9 mm stainless steel mandrel at an 11.4 mm pitch. The wraps were
repeated on a bias in opposite directions to produce an
approximately 4-layer film tube.
[0174] This tube was then thermally treated in an oven at
380.degree. C. for 9 minutes and then removed from the oven. The
tube was removed from the mandrel, placed over a 7 mm mandrel and
axially stretched to decrease its diameter to 7 mm. A sacrificial
ePTFE tape was helically wrapped over the film tube on the 7 mm
mandrel.
[0175] The tube assembly was then axially compressed to 85% of its
original length. The tube assembly was then subjected to thermal
treatment at 380.degree. C. for 1 minute and then removed from the
oven. The sacrificial ePTFE layer was removed and discarded. The 7
mm tube construct was cut to an 80 mm length. This tube can be
referred to as a "size limiting layer".
[0176] A compliant polyurethane balloon catheter was obtained with
a balloon having a diameter of 10 mm and length of 60 mm ("COAX,"
Bavarian Medizin Technologies (BMT), Germany).
[0177] The size limiting layer was slid over the balloon assembly
(with the balloon in its collapsed state). The ends of the size
limiting layer were secured to the catheter using LOCTITE adhesive
4981 (Henkel Corporation, Dusseldorf, 40589 Germany) applied to a 6
mm wide ePTFE tape as it was wrapped 5 times about the size
limiting layer tube ends. The balloon was then inflated to an
approximate 5 mm diameter.
[0178] The template layer, as described in Example 2, was slid over
the size-limiting layer and the compliant balloon (with the balloon
at its 5 mm diameter). The ends of the template layer were secured
to the catheter using LOCTITE adhesive 4981 applied to a 6 mm wide
ePTFE tape as it was wrapped 5 times about the tube ends. The
balloon was then inflated to an approximate 6 mm diameter.
[0179] The balloon assembly was then inflated to 4 atmospheres and
protrusions of the underlying compliant balloon were noted
extending from the apertures.
Example 3: Method of Making a Balloon Assembly Comprising a Size
Limiting Layer Overlaying a Compliant Balloon, Both of which are
Circumscribed by a Template with Apertures Having a First
Distension Profile and a Second Distension Profile
[0180] In order to form a distensible template, construct a
helically wrapped 8 mm film tube using an ePTFE film as described
in U.S. Pat. No. 7,306,729, issued Dec. 11, 2007. Laser cut the 8
mm film tube to form 2 mm.times.2 mm openings. Reduce the template
diameter by stretching the template in a longitudinal direction
until the inside diameter of the template reaches approximately 4
mm. Insert a 4 mm mandrel into the 4 mm drawn down template. Over
wrap the template on the 4 mm mandrel with a sacrificial film.
Longitudinally compress (or scrunch) the over-wrapped template to
approximately 60% of the original length. Bake the compressed
template at 380.degree. C. at a time ranging from (0 sec. to 120
sec.). This step sets the load at which the template will begin to
distend. The lower the baking time, the smaller the load required
to distend. Once set, remove the sacrificial film and the template
from the 4 mm mandrel.
[0181] Obtain an inflatable, compliant balloon element constructed
to be 8 mm.times.40 mm with a working length of 40 mm, two
shoulders of length of 4 mm, and two seals of 7 mm, giving it an
overall length of 62 mm.
[0182] Place an 8 mm.times.62 mm size limiting layer (constructed
in a similar manner as described in Example 2) that has also been
drawn down to 4 mm on a 4 mm mandrel. Cut the template to a length
of (24 mm+7 mm to form the attachment to the size limiting layer at
the seal), giving it an overall length of 31 mm. Slide the cut
template over the size limiting layer that is on the 4 mm mandrel
so the inside end of the template aligns with the center line of
the size limiting layer. Wrap approximately 5 to 20 layers of a
porous, sintered, sufficiently thin and strong ePTFE film,
1/2''wide using 4498 LocTite glue to adhere the template at center
line of the size limiting layer. Remove the size limiting layer
with the template attached from the 4 mm mandrel.
[0183] Place the 4 mm template and size limiting assembly over the
compacted 8 mm balloon and secure both the proximal and distal ends
(7 mm each) by wrapping approximately 10 or more layers of a
porous, sintered, sufficiently thin and strong ePTFE film and 4498
LocTite adhesive around each end of the cover and catheter.
[0184] In another embodiment, a frangible template can be
constructed as described in Example 3, instead using an ePTFE film
as described in U.S. Pat. No. 5,814,405 Branca et al., which is
hereby incorporated by reference in its entirety.
[0185] It will be apparent to those skilled in the art that various
modifications and variations can be made in the present disclosure
without departing from the spirit or scope of the disclosure. For
example, while embodiments of the present disclosure have been
described with reference to the inferior vena cava, embodiments are
scaleable and applications in various central and peripheral
vessels and lumens are contemplated herein. Additionally, the
embodiments can be used in connection with not just humans, but
also various organisms having mammalian anatomies. Thus, it is
intended that the embodiments described herein cover the
modifications and variations of this disclosure provided they come
within the scope of the appended claims and their equivalents.
[0186] Benefits, other advantages, and solutions to problems have
been described herein with regard to specific embodiments. However,
the benefits, advantages, solutions to problems, and any element or
combination of elements that can cause any benefit, advantage, or
solution to occur or become more pronounced are not to be construed
as critical, required, or essential features or elements of any or
all the claims of the disclosure. Many changes and modifications
within the scope of the instant disclosure can be made without
departing from the spirit thereof, and the disclosure includes all
such modifications. Corresponding structures, materials, acts, and
equivalents of all elements in the claims below are intended to
include any structure, material, or acts for performing the
functions in combination with other claim elements as specifically
claimed. The scope of the disclosure should be determined by the
appended claims and their legal equivalents, rather than by the
examples given above.
* * * * *