U.S. patent application number 14/680593 was filed with the patent office on 2015-10-08 for partially coated stents.
This patent application is currently assigned to BOSTON SCIENTIFIC SCIMED INC.. The applicant listed for this patent is Boston Scientific Scimed Inc.. Invention is credited to John Allen Hingston, Matthew B. Hollyer.
Application Number | 20150282922 14/680593 |
Document ID | / |
Family ID | 52992007 |
Filed Date | 2015-10-08 |
United States Patent
Application |
20150282922 |
Kind Code |
A1 |
Hingston; John Allen ; et
al. |
October 8, 2015 |
PARTIALLY COATED STENTS
Abstract
A medical product comprises a biodegradable filament and a
non-biodegradeable coating. The biodegradable filament forms a
stent body having a first end portion, a middle portion, and a
second end portion opposite the first end portion. The middle
portion extends between the first and second end portions. The
non-biodegradeable coating encapsulates the at least one
biodegradable filament along the middle portion of the stent body.
The non-biodegradeable coating forms a barrier such that the
non-biodegradeable coating prevents degradation of the at least one
biodegradable filament along the middle portion. The first and
second end portions are uncoated. After implantation, the end
portions of the stent may biodegrade. The middle portion will not
biodegrade due to its encapsulation by the non-biodegradeable
coating.
Inventors: |
Hingston; John Allen;
(Framingham, MA) ; Hollyer; Matthew B.;
(Williamstown, VT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Boston Scientific Scimed Inc. |
Maple Grove |
MN |
US |
|
|
Assignee: |
BOSTON SCIENTIFIC SCIMED
INC.
Maple Grove
MN
|
Family ID: |
52992007 |
Appl. No.: |
14/680593 |
Filed: |
April 7, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61976764 |
Apr 8, 2014 |
|
|
|
Current U.S.
Class: |
623/23.7 |
Current CPC
Class: |
A61L 31/048 20130101;
A61L 2420/00 20130101; A61L 31/148 20130101; A61F 2002/072
20130101; A61F 2002/9528 20130101; A61F 2/86 20130101; A61F 2/04
20130101; A61F 2250/0039 20130101; A61F 2250/0041 20130101; A61L
31/10 20130101; A61F 2/0077 20130101; A61F 2002/044 20130101; A61F
2/95 20130101; A61F 2250/0031 20130101; A61F 2250/0059 20130101;
A61F 2002/009 20130101; A61F 2210/0004 20130101; A61F 2250/003
20130101; A61F 2/07 20130101; A61F 2/90 20130101 |
International
Class: |
A61F 2/00 20060101
A61F002/00; A61L 31/14 20060101 A61L031/14; A61L 31/04 20060101
A61L031/04; A61L 31/10 20060101 A61L031/10; A61F 2/04 20060101
A61F002/04; A61F 2/95 20060101 A61F002/95 |
Claims
1. A stent comprising: at least one biodegradable filament forming
a stent body, the stent body having a first end portion, a middle
portion, and a second end portion opposite the first end portion,
the middle portion extending between the first and second end
portions; and a non-biodegradeable coating, the non-biodegradeable
coating encapsulating the at least one biodegradable filament along
the middle portion of the stent body and forming a barrier such
that the non-biodegradeable coating prevents degradation of the at
least one biodegradable filament along the middle portion, wherein
the first and second end portions are uncoated and
biodegradeable.
2. The stent of claim 1, wherein the at least one biodegradable
filament is a monofilament.
3. The stent of claim 1 further comprising a retrieval loop.
4. The stent of claim 3, wherein at least a portion of the
retrieval loop is routed through at least a portion of the middle
portion.
5. The stent of claim 1, wherein the stent has an unexpanded
configuration and an expanded configuration; in the expanded
configuration, at least one of the first end portion and second end
portion has a cross-sectional area greater than the cross-sectional
area of at least a portion of the middle portion.
6. The stent of claim 5, wherein, in the expanded configuration, at
least a portion of the first end portion and at least a portion of
the second end portion has a cross-sectional area greater than at
least a portion of the cross-sectional area of the middle
portion.
7. The stent of claim 1, wherein the at least one biodegradable
filament is formed from poly(lactic-co-glycolic) acid (PLGA),
polylactic acid (PLA), polyglycolic acid (PGA), poly(ortho ester)
(POE), poly(epsilon-caprolactone) (PCL), and
polyhydroxybutyrate-valerate (PHBV), or polydioxanone (PDO).
8. The stent of claim 1, wherein the non-biodegradeable coating is
formed from a silicone polymer, silicone copolymer, polyurethane,
polystyrene-polyethylene/butylene-polystyrene (SEBS) copolymer,
acrylate polymer, acrylate copolymer, methacrylate polymer,
methacrylate copolymer, fluorinated polymer, (modified)
ethylene-tetrafluoroethylene copolymer (ETFE) polymer,
polytetrafluoroethylene (PTFE),
poly(tetrafluoroethylene-co-hexafluoropropene) (FEP),
polyvinylidene fluoride (PVDF), and combinations thereof.
9. The stent of claim 1 further comprising a plurality of retrieval
loops.
10. The stent of claim 1, wherein the at least one biodegradable
filament is braided to form the stent body.
11. The stent of claim 1 further being an esophageal stent.
12. The stent of claim 1, wherein the stent body comprises a first
flared portion, a portion of the first flared portion being coated
with the non-biodegradeable coating and a portion of the flared
portion being uncoated.
13. The stent of claim 12, wherein the stent body comprises a
second flared portion, a portion of the second flared portion being
coated with the non-biodegradeable coating and a portion of the
second flared portion being uncoated.
14. A stent comprising: at least one biodegradable filament forming
a braided stent body, the braided stent body having a first end
portion, a middle portion, and a second end portion opposite the
first end portion, the middle portion extending between the first
and second end portions; a non-biodegradeable coating, the
non-biodegradeable coating encapsulating the at least one
biodegradable filament along the middle portion of the braided
stent body and forming a barrier such that the non-biodegradeable
coating prevents degradation of the at least one biodegradable
filament along the middle portion, wherein the first and second end
portions are uncoated and biodegradeable; and at least one
retrieval loop threaded through at least a portion of the middle
portion of the braided stent body.
15. The stent of claim 14, wherein the at least one retrieval loop
comprises a first retrieval loop and a second retrieval loop, the
second retrieval loop threaded through at least a portion of the
middle portion, the second retrieval loop being longitudinally
offset from the first retrieval loop.
16. The stent of claim 14, wherein the stent has an unexpanded
configuration and an expanded configuration; in the expanded
configuration, at least one of the first end portion and second end
portion has a cross-sectional area greater than the cross-sectional
area of at least a portion of the middle portion.
17. The stent of claim 16, wherein, in the expanded configuration,
at least a portion of the first end portion and at least a portion
of the second end portion has a cross-sectional area greater than
the cross-sectional area of at least a portion of the middle
portion.
18. The stent of claim 14, wherein the at least one biodegradable
filament is formed from poly(lactic-co-glycolic) acid (PLGA),
polylactic acid (PLA), polyglycolic acid (PGA), poly(ortho ester)
(POE), poly(epsilon-caprolactone) (PCL), and
polyhydroxybutyrate-valerate (PHBV), or polydioxanone (PDO).
19. The stent of claim 18, wherein the non-biodegradeable coating
is formed from a silicone polymer, silicone copolymer,
polyurethane, polystyrene-polyethylene/butylene-polystyrene (SEBS)
copolymer, acrylate polymer, acrylate copolymer, methacrylate
polymer, methacrylate copolymer, fluorinated polymer, (modified)
ethylene-tetrafluoroethylene copolymer (ETFE) polymer,
polytetrafluoroethylene (PTFE),
poly(tetrafluoroethylene-co-hexafluoropropene) (FEP),
polyvinylidene fluoride (PVDF), and combinations thereof.
20. The stent of claim 19, wherein the stent body defines a
plurality of interstices, the interstices being covered by the
non-biodegradeable coating along the middle portion of the stent
body, thereby preventing tissue ingrowth therealong.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This Application claims the benefit of and priority to U.S.
Provisional Application No. 61/976,764, filed Apr. 8, 2014, the
entire contents of which are herein incorporated by reference.
TECHNICAL FIELD
[0002] The present disclosure pertains to medical devices, systems,
and methods for using medical devices. More particularly, the
present disclosure pertains to a partially coated stent.
BACKGROUND
[0003] Stents are typically tubular endoprostheses used for
supporting a diseased or traumatized lumen. For example, stents may
be used in body vessels such as in coronary or peripheral
vasculature, an esophagus, trachea, bronchi, colon, biliary tract,
urinary tract, prostate, brain, or in other bodily locations.
[0004] Generally, stents can be permanent or temporary depending on
the treatment requirements. Stents may be permanently retained in a
patient's body, for example, or for an indeterminate amount of
time. Further, some stents are designed to remain in a patient's
body temporarily.
[0005] After implantation, in some cases, stents migrate from the
treatment location, for example, due to exposure to flow of bodily
fluids or peristalsis. In order to counteract migration, stents may
be partially covered or uncovered, allowing tissue ingrowth into
the stent.
[0006] As discussed above, on occasion it may be useful to retrieve
the stent previously deployed in a body lumen. In covered or
partially covered stents, however, tissue ingrowth takes places and
hence it becomes challenging to remove the stent from the body.
[0007] Therefore, there remains a need for a stent that is less
likely to migrate and can also be removed easily, as needed.
SUMMARY
[0008] In at least one embodiment, a stent comprises at least one
biodegradable filament and a non-biodegradeable coating. The at
least one biodegradable filament forms a stent body having a first
end portion, a middle portion, and a second end portion opposite
the first end portion. The middle portion extends between the first
and second end portions. The non-biodegradeable coating
encapsulates the at least one biodegradable filament along the
middle portion of the stent body. The non-biodegradeable coating
forms a barrier such that the non-biodegradeable coating prevents
degradation of the at least one biodegradable filament along the
middle portion. The first and second end portions are uncoated.
[0009] In at least one embodiment, a stent comprises at least one
biodegradable monofilament, a non-biodegradeable coating, and at
least one retrieval loop. The at least one biodegradable
monofilament forms a braided stent body. The braided stent body has
a first end portion, a middle portion, and a second end portion
opposite the first end portion. The middle portion extends between
the first and second end portions. The non-biodegradeable coating
encapsulates the at least one biodegradable monofilament along the
middle portion of the braided stent body and forms a barrier such
that non-biodegradeable coating prevents degradation of at least
one biodegradable monofilament along the middle portion. The first
and second end portions are uncoated. The retrieval loop is
threaded through at least a portion of the middle portion of the
braided stent body.
[0010] The above summary of some embodiments is not intended to
describe each disclosed embodiment or every implementation of the
present disclosure. The Figures and Detailed Description, which
follow, more particularly exemplify these embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] A detailed description of the invention is hereafter
described with specific reference being made to the drawings.
[0012] FIG. 1 is a side-view of an embodiment of a stent in an
expanded configuration.
[0013] FIG. 2 is a side-view of the embodiment of FIG. 1 in an
unexpanded configuration.
[0014] FIG. 3 shows a side-view of an embodiment of a stent in an
expanded configuration.
[0015] While the disclosure is amenable to various modifications
and alternative forms, specifics thereof have been shown by way of
example in the drawings and will be described in detail. It should
be understood, however, that the intention is not to limit the
invention to the particular embodiments described. On the contrary,
the intention is to cover all modifications, equivalents, and
alternatives falling within the spirit and scope of the
disclosure.
DETAILED DESCRIPTION
[0016] Definitions are provided for the following defined terms. It
is intended that these definitions be applied, unless the context
indicates otherwise.
[0017] The recitation of numerical ranges by endpoints includes all
numbers within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75,
3, 3.80, 4, and 5).
[0018] As used herein, the singular forms "a", "an", and "the"
include plural references unless the context clearly indicates
otherwise. As used herein, the term "or" is generally employed in
its sense including "and/or" unless the context clearly evidences
or indicates otherwise.
[0019] References herein to "an embodiment," "some embodiments,"
"other embodiments," etc., indicate that an embodiment includes a
particular feature, structure, or characteristic, but not every
embodiment necessarily includes the particular feature, structure,
or characteristic. Moreover, such phrases do not necessarily refer
to the same embodiment. Further, when a particular feature,
structure, or characteristic is described in connection with an
embodiment (or more embodiments), it should be understood that such
feature, structure, or characteristic may also be used in
connection with other embodiments, whether or not explicitly
described, unless clearly evidenced or stated to the contrary.
[0020] The following detailed description should be read with
reference to the drawing(s). The drawing(s), which is/are not
necessarily to scale, depict one or more illustrative embodiments
and is/are not intended to limit the scope of the disclosure.
[0021] FIG. 1 is a side-view of a stent 100 that can be implanted
in a body lumen (e.g., esophagus, vessel, trachea, bronchi, colon,
biliary tract, urinary tract, prostate, brain, duodenum, or other
tubular lumen or location) to treat various conditions. As shown,
the stent 100 includes a stent body 102 having a first end portion
104, a second end portion 106, and a middle portion 108 extending
between the first end portion 104 and the second portion 106. In
some embodiments, the stent body 102 has a hollow, tubular
structure defining a central lumen through which body fluid, such
as mucus or blood, can pass.
[0022] The stent 100 has an expanded configuration 202 and an
unexpanded configuration 204 (FIG. 2). In the unexpanded
configuration 204, the stent 100 has a radially reduced profile; in
the expanded configuration 202, the stent 100 has a radially
increased profile which can conform to the geometry of a body lumen
and, in some embodiments, expand the body lumen. The stent 100 may
be delivered to a treatment location through an introducer sheath,
endoscope, guide catheter, exterior tube, or via any other suitable
delivery device. Further, the stent 100 can be delivered over a
guide wire. During delivery, in at least some embodiments, the
stent 100 is in the unexpanded configuration 204.
[0023] After stent 100 is delivered to the treatment location, the
stent 100 may assume the expanded configuration 202 within the body
lumen. In some embodiments, in the expanded configuration 202, a
cross-sectional area of at least a portion of the stent body 102
(for example, both the first end portion 104 and the second end
portion 106) is greater than a cross-sectional area of at least a
portion of the middle portion 108. In some embodiments, the
cross-sectional area of either the first end portion 104 or the
second end portion 106 is greater than at least a portion of the
middle portion 108. In some embodiments, one or more of the first
end portion 104, the second end portion 106, and the middle portion
108 have varying cross-sectional area. In some embodiments, the
stent 100 has one or more flared portions, for example flared ends.
In some embodiments, for example as shown in FIG. 1, a first flared
portion 118 extends along the entire length of first end portion
104 and along a portion of the middle portion 108. Further, in some
embodiments, a second flared portion 120 extends along the entire
length of the second end portion 106 and along a portion of the
middle portion 108. The one or more flared portions may have an
abrupt transition of cross-section or smooth transition.
[0024] To deploy the stent 100, a physician may transition the
stent 100 between the expanded configuration 202 and the unexpanded
configuration 204 using an actuation mechanism, e.g., push-pull
mechanism or balloon. In some embodiments, the stent 100 is
self-expanding.
[0025] In some embodiments, the stent body 102 is formed by
braiding one or more biodegradable filaments 110. In some
embodiments, the one or more biodegradable filaments 110 have a
monofilament structure. Alternatively, in some embodiments, the
biodegradable filaments 110 comprise a multi-filament structure. In
some embodiments, the biodegradable filaments 110 are braided in a
helical pattern, although other arrangements are also suitable.
Also, the braiding pattern includes interstices 114 in between the
biodegradable filaments 110. The interstices 114 allow tissue
ingrowth and thereby prevent or resist migration.
[0026] The biodegradable filaments 110 may be formed using a
suitable biodegradable material, particularly materials that may be
formed into fibers or filaments. Further, in some embodiments, the
biodegradable filaments 110 are flexible to allow formation of
patterns or braiding, but also have suitable radial strength.
Examples of such materials include, for example,
poly(lactic-co-glycolic)acid, polyglycolic acid, polylactic acid,
or the like. Such materials may degrade, disintegrated, or be
absorbed in the body within a few weeks to few months, for example,
3, 4, 5, 6, 10, 12, 18 months.
[0027] In some embodiments, the stent 100 includes a
non-biodegradeable coating 112 disposed on the filaments 110 of the
middle portion 108, encapsulating the biodegradable filaments 110
therealong. In at least some embodiments, the non-biodegradeable
coating 112 forms a barrier to prevent the biodegradable filaments
110 from degrading or being absorbed within the body. To this end,
the non-biodegradeable coating 112 covers the biodegradable
filaments 110 both on an outer surface and inner surface of the
stent body 102 such that bodily fluids cannot readily degrade the
filaments 110 along the middle portion 108 of the stent body
102
[0028] Additionally, in some embodiments, the non-biodegradeable
coating 112 is disposed such that the first and second end portions
104, 106 of the stent body 102 remain uncoated. In this way, prior
to implantation, the stent 100 is a partially coated stent. As the
first end portion 104 and the second end portion 106 remain
uncoated, tissue is permitted to ingrow into these portions. The
tissue ingrowth secures the stent 100 within the body lumen,
preventing migration of the stent 100. Further, the uncoated first
and second end portions 104, 106 may biodegrade within the body
lumen over a period of time, leaving behind a fully coated stent
(e.g., the middle portion 108). Due to the non-biodegradeable
coating 112, in some embodiments, the remaining stent 100 (e.g.,
the middle portion 108) does not have tissue grown into the
interstices 114 and, consequently, a physician can retrieve and
remove the stent 100 from the body lumen.
[0029] The non-biodegradeable coating 112 can be disposed on the
stent 100 in any desirable way. For example, in some embodiments,
the entirety of the stent 100 is coated with the non-biodegradeable
coating 112 except for the first flared portion 118. Further, in
some embodiments, the entirety of the stent 100 is coated with the
non-biodegradeable coating 112 except for the second flared portion
120. And, in some embodiments, the entirety of the stent 100 is
coated with the non-biodegradeable coating 112 except for the first
flared portion 118 and the second flared portion 120, for example
as shown in FIG. 3. In such an embodiments, the flared portions
118, 120 degrade, leaving the remaining portion of the stent 100
(e.g., middle portion 108) behind.
[0030] The non-biodegradeable coating 112 can be formed using any
suitable technique, for example spray coating, dip coating, vapor
deposition coating, extrusion, or a combination of these
techniques. In some embodiments, the non-biodegradeable coating 112
is applied and secured to the stent body 102 by adhesive bonding,
conformal coating, or any suitable combination of these techniques,
including a combination of adhesive bonding and conformal coating.
In some embodiments, the non-biodegradeable coating 112 is formed
from a suitable biocompatible material. In some embodiments, the
non-biodegradeable coating 112 is an impermeable material that
creates a barrier, preventing bodily fluid from coming into contact
with encapsulated biodegradable filament 110, thereby preventing
biodegradation of middle portion 108 of the stent 100. In some
embodiments, the non-biodegradeable coating 112 not only forms a
barrier around the filament but also acts as a covering over the
interstices 114, thereby preventing tissue ingrowth and also
preventing degradation of the 110 by bodily fluids. In this way,
the middle portion 108 of the stent remains intact after
degradation of the first and second ends 104, 106 such that it can
be removed from the body lumen.
[0031] Examples of suitable materials for the non-biodegradeable
coating 112 may include, but are not limited to, polyurethane (PU),
polyethylene (PE), polytetrafluoroethylene (PTFE), or expanded
polytetrafluoroethylene (ePTFE), polyolefins such as high density
polyethylene (HDPE) and polypropylene (PP), polyolefin copolymers
and terpolymers, polyethylene terephthalate (PET), polyesters,
polyamides, polyurethaneureas and polycarbonates, polyvinyl
acetate, thermoplastic elastomers including polyether-polyester
block copolymers, polyvinyl chloride, polystyrene, polyacrylate,
polymethacrylate, polyacrylonitrile, polyacrylamide, silicone
resins, combinations and copolymers thereof.
[0032] In some embodiments, the stent 100 includes one or more
retrieval loops 116a, 116b to facilitate easy retrieval of
non-degraded portion of the stent 100. In some embodiments, the
retrieval loop(s) are routed through a portion of the middle
portion 108 of the stent 100, for example adjacent to the first or
second end portion 104, 106. The retrieval loop(s) 116a, 116b may
be gripped and pulled to retrieve the stent 100 from the body
lumen. The retrieval loop(s) 116a, 116b may be pulled using a
device such as, forceps (e.g., rat tooth foreceps). Any other
suitable retrieval device can also be used.
[0033] As shown for example in FIG. 1, the first retrieval loop
116a is longitudinally offset from the second retrieval loop 116b.
As a result of having two retrieval loops 116a, 116b, one at or
near each end of the degraded stent, the stent 100 can be retrieved
from either end.
[0034] In some other embodiments, the retrieval loop(s) 116a, 116b
are secured to an outer surface of the stent 100 or
non-biodegradeable coating 112, for example via an adhesive. In
some embodiments, however, one or more retrieval loops 116a, 116b
are routed through one or more of the interstices 114. Further, in
some embodiments, a portion of the retrieval loop(s) 116a, 116b may
be braided into the structure of the stent 100, forming an integral
part of the stent structure. In some embodiments, one or more
retrieval loop(s) 116a, 116b are formed from a biomaterial. In some
embodiments, one or more retrieval loop(s) 116a, 116b are formed
from a non-biodegradable material. In some embodiments, one or more
retrieval loop(s) 116a, 116b are formed from a shape memory
material, such as a shape memory metal, for example a
nickel-titanium alloy.
[0035] A description of some embodiments of the heat treatments is
contained in one or more of the following numbered statements:
Statement 1. A stent comprising:
[0036] at least one biodegradable filament forming a stent body,
the stent body having a first end portion, a middle portion, and a
second end portion opposite the first end portion, the middle
portion extending between the first and second end portions;
and
[0037] a non-biodegradeable coating, the non-biodegradeable coating
encapsulating the at least one biodegradable filament along the
middle portion of the stent body and forming a barrier such that
the non-biodegradeable coating prevents degradation of the at least
one biodegradable filament along the middle portion, wherein the
first and second end portions are uncoated and biodegradeable.
Statement 2. The stent of statement 1, wherein the at least one
biodegradable filament is a monofilament. Statement 3. The stent of
any one of the preceding statements, wherein the stent has an
unexpanded configuration and an expanded configuration; in the
expanded configuration, at least one of the first end portion and
second end portion has a cross-sectional area greater than the
cross-sectional area of at least a portion of the middle portion.
Statement 4. The stent of statement 3, wherein, in the expanded
configuration, at least a portion of the first end portion and at
least a portion of the second end portion has a cross-sectional
area greater than at least a portion of the cross-sectional area of
the middle portion. Statement 5. The stent of any one of the
preceding statements, wherein the at least one biodegradable
filament is formed from poly(lactic-co-glycolic) acid (PLGA),
polylactic acid (PLA), polyglycolic acid (PGA), poly(ortho ester)
(POE), poly(epsilon-caprolactone) (PCL), and
polyhydroxybutyrate-valerate (PHBV), or polydioxanone (PDO).
Statement 6. The stent of any one of the preceding statements,
wherein the non-biodegradeable coating is formed from a silicone
polymer, silicone copolymer, polyurethane,
polystyrene-polyethylene/butylene-polystyrene (SEBS) copolymer,
acrylate polymer, acrylate copolymer, methacrylate polymer,
methacrylate copolymer, fluorinated polymer, (modified)
ethylene-tetrafluoroethylene copolymer (ETFE) polymer,
polytetrafluoroethylene (PTFE),
poly(tetrafluoroethylene-co-hexafluoropropene) (FEP),
polyvinylidene fluoride (PVDF), and combinations thereof. Statement
7. The stent of any one of the preceding statements further
comprising at least one retrieval loop. Statement 8. The stent of
statement 7, wherein at least a portion of the retrieval loop is
routed through at least a portion of the middle portion. Statement
9. The stent of statement 7 further comprising a plurality of
retrieval loops. Statement 10. The stent of statement 9, wherein
the plurality of retrieval loops comprises a first retrieval loop
and a second retrieval loop, the second retrieval loop threaded
through at least a portion of the middle portion, the second
retrieval loop being longitudinally offset from the first retrieval
loop. Statement 11. The stent of statement 7, 8, 9, or 10 wherein
the at least one retrieval loop is formed from a shape memory
material. Statement 12. The stent of statement 11, wherein the
shape memory material is a nickel-titanium alloy. Statement 13. The
stent of any one of the preceding statements further being an
esophageal stent. Statement 14. The stent of any one of the
preceding statements, wherein the at least one biodegradable
filament is braided to form the stent body. Statement 15. The stent
of any one of the preceding statements, wherein the stent body
defines a plurality of interstices, the interstices being covered
by the non-biodegradeable coating along the middle portion of the
stent body, thereby preventing tissue ingrowth therealong.
Statement 16. The stent of any of the preceding statements, wherein
the stent body comprises a first flared portion, a portion of the
first flared portion being coated with the non-biodegradeable
coating and a portion of the flared portion being uncoated.
Statement 17. The stent of statement 16, wherein the stent body
comprises a second flared portion, a portion of the second flared
portion being coated with the non-biodegradeable coating and a
portion of the second flared portion being uncoated. Statement 18.
The stent of statement 16, wherein the first and second flared
portions are uncoated.
[0038] It should be understood that this disclosure is, in many
respects, only illustrative. Changes may be made in details,
particularly in matters of shape, size, and arrangement of steps
without exceeding the scope of the disclosure. This may include, to
the extent that it is appropriate, the use of any of the features
of one example embodiment being used in other embodiments. The
invention's scope is, of course, defined in the language in which
the appended claims are expressed.
* * * * *