U.S. patent application number 09/750934 was filed with the patent office on 2002-03-28 for hybrid elastomer sleeve for stent delivery.
Invention is credited to Chen, John Jianhua, Chin, Albert C. C., Horn, Daniel J., Miller, Paul J., Seppala, Jan D., Yang, Dachuan.
Application Number | 20020038140 09/750934 |
Document ID | / |
Family ID | 24682527 |
Filed Date | 2002-03-28 |
United States Patent
Application |
20020038140 |
Kind Code |
A1 |
Yang, Dachuan ; et
al. |
March 28, 2002 |
Hybrid elastomer sleeve for stent delivery
Abstract
A stent delivery system comprising a catheter. The catheter
including a stent mounting region and a stent disposed thereabout.
The stent having a distal end and a proximal end, and an unexpanded
state and an expanded state. At least one stent retaining sleeve,
having a first end and a second end, wherein the first end overlays
an end of the stent when the stent is in the unexpanded state. The
second end engaged to at least a portion of the catheter adjacent
to the stent mounting region. The stent retaining sleeve(s)
comprising a first material and at least one substantially
longitudinally oriented fiber of a second material. The first
material having a predetermined tensile modulus and the second
material having a predetermined tensile modulus, wherein the
predetermined tensile modulus of the second material is greater
than that of the first material.
Inventors: |
Yang, Dachuan; (Plymouth,
MN) ; Miller, Paul J.; (St. Paul, MN) ;
Seppala, Jan D.; (Maple Grove, MN) ; Chin, Albert C.
C.; (Newton, MA) ; Chen, John Jianhua;
(Plymouth, MN) ; Horn, Daniel J.; (Shoreview,
MN) |
Correspondence
Address: |
VIDAS, ARRETT & STEINKRAUS, P.A.
6109 BLUE CIRCLE DRIVE
SUITE 2000
MINNETONKA
MN
55343-9185
US
|
Family ID: |
24682527 |
Appl. No.: |
09/750934 |
Filed: |
December 29, 2000 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09750934 |
Dec 29, 2000 |
|
|
|
09668496 |
Sep 22, 2000 |
|
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Current U.S.
Class: |
623/1.12 |
Current CPC
Class: |
A61F 2002/9583 20130101;
A61F 2250/0019 20130101; A61F 2/958 20130101 |
Class at
Publication: |
623/1.12 |
International
Class: |
A61F 002/06 |
Claims
1. A stent delivery system comprising: a catheter including a stent
mounting region; a stent disposed about the stent mounting region
of the catheter, the stent having a distal end and a proximal end,
the stent further having a unexpanded state and an expanded state,
and at least one stent retaining sleeve, the at least one stent
retaining sleeve having a first end and a second end, the first end
overlying an end of the stent when the stent is in the unexpanded
state, the second end engaged to at least a portion of the catheter
adjacent to the stent mounting region, the at least one stent
retaining sleeve comprising a first material and at least one
substantially longitudinally oriented fiber of a second material,
the first material having a first predetermined tensile modulus and
the second material having a second predetermined tensile modulus,
the second predetermined tensile modulus being greater than that of
the first predetermined tensile modulus.
2. The stent delivery catheter of claim 1, the at least one
substantially longitudinally oriented fiber of a second material
further comprising a plurality of substantially longitudinally
oriented fibers.
3. The stent delivery catheter of claim 1 wherein the at least one
substantially longitudinally oriented fiber of a second material
further comprises a first portion and a second portion, the first
portion having a first predetermined width, and the second portion
having a second predetermined width, the first predetermined width
being less than the second predetermined width, the first portion
substantially oriented toward the first end of the at least one
stent retaining sleeve and the second portion substantially
oriented toward the second end of the at least one stent retaining
sleeve. The first predetermined width tapering to the second
predetermined width.
4. The stent delivery catheter of claim 3 wherein the first
predetermined width is 30 zero.
5. The stent delivery catheter of claim 1 wherein the at least one
substantially longitudinally oriented fiber of a second material is
characterized as being substantially sinusoidal in shape.
6. The stent delivery catheter of claim 1 wherein the first
material and the at least one substantially longitudinally oriented
fiber of a second material are co-extruded.
7. The stent delivery catheter of claim 1 wherein the substantially
longitudinally oriented fiber of a second material is a wire, the
wire engaged to the first material of the at least one stent
retaining sleeve.
8. The stent delivery catheter of claim 1 wherein the substantially
longitudinally oriented fiber of a second material is at least
partially compose of a polymer.
9. The stent delivery catheter of claim 1, the at least one stent
retaining sleeve having a predetermined thickness and the first
material having at least one groove, the at least one groove having
a predetermined thickness less than the predetermined thickness of
the at least one stent retaining sleeve, at least one substantially
longitudinally oriented fiber of a second material positioned
within the at least one groove.
10. The stent delivery system of claim 1 wherein the first material
has a predetermined thickness and the at least one substantially
longitudinally oriented fiber of a second material has a
predetermined thickness, wherein the predetermined thickness of the
first material and the predetermined thickness of the at least one
substantially longitudinally oriented fiber of a second material
are the same.
11. The stent delivery system of claim 2, the at least one stent
retaining sleeve further comprising a circumference, the plurality
of substantially longitudinally oriented fibers being uniformly
spaced apart about a the circumference.
12. The stent delivery catheter of claim 2, the at least one stent
retaining sleeve further comprising a circumference, the plurality
of substantially longitudinally oriented fibers are randomly
dispersed about the circumference.
13. The stent delivery system of claim 1 wherein the first material
is constructed from at least one member of the group consisting of:
styrenic block copolymers, polyurethanes, silicone rubber, natural
rubber, copolyesters, polyamides, EPDM rubber/polyolefin, nitril
rubber/PVC, fluoroelastomers, butyl rubber, epichlorohydrin, and
any combinations thereof.
14. The stent delivery system of claim 1 wherein the at least one
substantially longitudinally oriented fiber of a second material is
constructed from at least one member of the group consisting of:
liquid crystal polymers, polyolefins, polystyrene, polyvinyl
chloride, acrylonitrile-butadiene-styrene polymers,
polyacrylonitrile, polyacrylate, vinyl acetate polymer, cellulose
plastics, polyurethanes, polyethylene terephthalate, polyacetal,
polyethers, polycarbonates, polyamides, polyphenylene sulfide,
polyarylethersulfones, polyaryletherketones,
polytetrafluoroethylene, polyethyleneterephthalate, nylon, metal,
carbon, glass and any combinations thereof.
15. The stent delivery catheter of claim 1, the first end of the at
least one stent retaining sleeve having an unexpanded diameter and
an expanded diameter, the expanded diameter of the first end being
up to approximately 400 percent greater than the unexpanded
diameter; whereby when the balloon is expanded from the unexpanded
state to the expanded state the unexpanded diameters of the first
end of the at least one stent retaining sleeve is increased by up
to approximately 400 percent to the expanded diameter.
16. A stent retaining sleeve for retaining stent ends on a balloon
catheter comprising: a tubular member composed of a first material
and at least one substantially longitudinally oriented fiber of a
second material, wherein the first material has a predetermined
tensile modulus and the second material has a predetermined tensile
modulus, the predetermined tensile modulus of the second material
being greater than the predetermined tensile modulus of the first
material; the tubular member having a first end and a second end,
the first end constructed and arranged to overlay an end of a
stent, the second end constructed and arranged to be in contact
with at least a portion of a catheter; the first end of the tubular
member having an unexpanded diameter and an expanded diameter
whereby when the balloon catheter is expanded the unexpanded
diameter increases by up to 400 percent to the expanded
diameter.
17. The stent retaining sleeve of claim 16, the sleeve having an
unexpanded length and an expanded length, the unexpanded length
being substantially the same as the expanded length.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation-In-Part application from
U.S. application Ser. No. 09/668,496, filed Sep. 22, 2000, the
entire contents of which is hereby incorporated by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
[0002] Not Applicable
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] This invention relates to medical device delivery catheters
in general, and specifically to balloon catheters for use in
delivering a medical device such as a stent to a desired body
location, such as in a blood vessel. More specifically, this
invention relates to a stent retaining sock or sleeve composed of a
generally elastic material, but which also includes at least one
substantially longitudinally oriented fiber or filament which has a
higher tensile modulus than the surrounding elastic material. The
combination of the elastomeric sleeve material and reinforcing
fiber(s) provides for a sleeve, which when mounted on a stent
delivery balloon catheter, may be made to expand in the radial
direction with limited or no elongation in the longitudinal
direction.
[0005] 2. Description of the Related Art
[0006] Stents and stent delivery assemblies are utilized in a
number of medical procedures and situations, and as such their
structure and function are well known. A stent is a generally
cylindrical prosthesis introduced via a catheter into a lumen of a
body vessel in a configuration having a generally reduced diameter
and then expanded to the diameter of the vessel. In its expanded
configuration, the stent supports and reinforces the vessel walls
while maintaining the vessel in an open, unobstructed
condition.
[0007] Both self-expanding and inflation expandable stents are well
known and widely available in a variety of designs and
configurations. Self-expanding stents must be maintained under
positive external pressure in order to maintain their reduced
diameter configuration during delivery of the stent to its
deployment site. Inflation expandable stents may be crimped to
their reduced diameter about the delivery catheter, maneuvered to
the deployment site, and expanded to the vessel diameter by fluid
inflation of a balloon positioned on the delivery catheter. The
present invention is particularly concerned with delivery and
deployment of inflation expandable stents, although it is generally
applicable to self-expanding stents when used with balloon
catheters.
[0008] In advancing an inflation expandable stent through a body
vessel to the deployment site, there are a number of important
considerations. The stent must be able to securely maintain its
axial position on the delivery catheter, without translocating
proximally or distally, and especially without becoming separated
from the catheter. The stent, particularly its distal and proximal
ends, must be protected to prevent distortion of the stent and to
prevent abrasion and/or reduce trauma of the vessel walls.
[0009] Inflation expandable stent delivery and deployment
assemblies are known which utilize restraining means that overlie
the stent during delivery. U.S. Pat. No. 4,950,227 to Savin et al,
relates to an expandable stent delivery system in which a sleeve
overlaps the distal or proximal margin (or both) of the stent
during delivery. That patent discloses a stent delivery system in
which a catheter carries, on its distal end portion, a stent which
is held in place around the catheter prior to and during
percutaneous delivery by means of one and preferably two sleeves.
The sleeves are positioned around the catheter with one end portion
attached thereto and overlap an end portion(s) of the stent to hold
it in place on the catheter in a contracted condition. Each sleeve
is elastomeric in nature so as to stretch and release the stent
when it expands for implantation. The stent is expandable by means
of the expandable balloon on the catheter. During expansion of the
stent at the deployment site, the stent margins are freed of the
protective sleeve(s). U.S. Pat. No. 5,403,341 to Solar, relates to
a stent delivery and deployment assembly which uses retaining
sheaths positioned about opposite ends of the compressed stent. The
retaining sheaths of Solar are adapted to tear under pressure as
the stent is radially expanded, thus releasing the stent from
engagement with the sheaths. U.S. Pat. No. 5,108,416 to Ryan et
al., describes a stent introducer system which uses one or two
flexible end caps and an annular socket surrounding the balloon to
position the stent during introduction to the deployment site.
[0010] Copending U.S. patent application Ser. No. 09/426,384 which
was filed Oct. 26, 1999 and entitled Longitudinal Dimensional
Stable Balloons, and which is incorporated in its entirety herein
by reference describes material having longitudinally oriented
fibers.
[0011] Copending U.S. patent application Ser. No. 09/407,836 which
was filed on Sep. 28, 1999 and entitled Stent Securement Sleeves
and Optional Coatings and Methods of Use, and which is incorporated
in its entirety herein by reference, also provides for a stent
delivery system having sleeves. In Ser. No. 09/407,836 the sleeves
may be made up of a combination of polytetrafluoroethylene (PTFE)
as well as one or more thermoplastic elastomers. Other references
exist which disclose a variety of stent retaining sleeves.
[0012] A common problem which occurs in catheter assemblies is
friction or adhesion between various parts which periodically come
into contact with one another during the medical procedure. For
instance, friction can occur between the guide catheter and guide
wire, between the introducer sheath and the guide catheter, or
between the guide catheter and the balloon catheter, for instance,
and may increase the difficulty of insertion, cause loss of
catheter placement, and result in discomfort to the patient or
damage to the vasculature. In catheters equipped with stent
retaining socks or sleeves, friction between the balloon and
sleeve, and/or the stent and sleeve may also cause retraction of
the sleeves to be made more difficult. It is therefore desirable to
reduce the friction due to the sliding between the various parts of
the catheter assemblies. Copending U.S. application Ser. No.
09/549,286 was filed Apr. 14, 2000 describes a reduced columnar
strength stent retaining sleeve having a plurality of holes. The
relatively reduced columnar and radial strength provided by the
holes allows the sleeve to be retracted off of a stent without the
need for lubricant.
[0013] Lubricants of many types have been used in conjunction with
balloon catheters. Both hydrophilic and hydrophobic coatings and
lubricants are well known in the catheter art. The present
invention may be used in conjunction with any type of lubricious
substance suitable for use with a stent delivery catheter, and is
further directed to the application of the lubricious substance to
the surface of a balloon cone and/or waste subsequent to stent
mounting and sleeve placement onto the catheter.
[0014] Copending U.S. patent application Ser. No. 09/407,836 which
was filed on Sep. 28, 1999 and entitled Stent Securement Sleeves
and Optional Coatings and Methods of Use, provides for a stent
delivery system having sleeves. In Ser. No. 09/407,836 the sleeves
may be made up of a combination of polytetrafluoroethylene
(hereinafter PTFE) as well as one or more thermoplastic elastomers.
Copending U.S. patent application Ser. No. 09/427,805 filed Oct.
27, 1999, and entitled End Sleeve Coating for Stent Delivery,
describes the use of stent retaining sleeves having lubricious
coatings applied thereto. Copending U.S. patent application Ser.
No. 09/273,520 filed Mar. 22, 1999, entitled Lubricated Sleeve
Material For Stent Delivery likewise describes the use of stent
retaining sleeves and lubricants.
[0015] The entire content of all patents and applications listed
within the present patent application are incorporated herein by
reference.
BRIEF SUMMARY OF THE INVENTION
[0016] In at least one embodiment, the instant invention is
directed to a medical device delivery system comprising a catheter
assembly having a medical device receiving region and at least one
retaining sleeve for retaining the medical device on the receiving
region prior to delivery. An expandable medical device, such as a
stent, is disposed about the medical device receiving region of the
catheter assembly. At least one retaining sleeve is disposed about
an end of the expandable medical device and at least a portion of
the catheter assembly.
[0017] The at least one retaining sleeve comprises a first material
and a second material. The first and second materials having a
different tensile modulus, the second material being one or more
substantially longitudinally oriented fibers or filaments of a
predetermined material or combination of materials. The fiber
material may overlay, be imbedded, co-extruded, woven, or otherwise
placed into the matrix of the first material.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0018] A detailed description of the invention is hereafter
described with specific reference being made to the drawings in
which:
[0019] FIG. 1 is a perspective view of an embodiment of the
invention;
[0020] FIG. 2 is a perspective view of an embodiment of the
invention;
[0021] FIG. 3 is a perspective view of an embodiment of the
invention;
[0022] FIG. 4 is a perspective view of an embodiment of the
invention;
[0023] FIG. 5 is a perspective view of an embodiment of the
invention;
[0024] FIG. 6 is across-sectional view of the embodiment of the
invention shown in FIG. 5;
[0025] FIG. 7 is a perspective view of an embodiment of the
invention;
[0026] FIG. 8 is a cross-sectional view of the embodiment of the
invention shown in FIG. 7;
[0027] FIG. 9 is a perspective view of an embodiment of the
invention;
[0028] FIG. 10 is a cross-sectional view of the embodiment of the
invention shown in FIG.9;
[0029] FIG. 11 is a perspective view of an embodiment of the
invention; and
[0030] FIG. 12 is a cross-sectional view of the embodiment of the
invention shown in FIG. 11.
DETAILED DESCRIPTION OF THE INVENTION
[0031] As may be seen in FIG. 1, the present invention may be
embodied in a stent delivery catheter, indicated generally at 10.
Catheter 10, includes a stent mounting region 12, the stent
mounting region 12 may be an inflatable portion of the catheter or
may be a separate balloon mounted to the catheter shaft 14. The
balloon 12 may have an unexpanded state and an expanded state. A
stent 16, disposed about the stent mounting region 12 may be
delivered when the balloon 12 is expanded to the expanded
state.
[0032] The stent 16 includes a proximal end 18 and a distal end 20.
In the embodiment shown a stent retaining sleeve 22 overlies at
least a portion of each end 18 and 20. As is known in the art, when
the balloon 12 and stent 16 are expanded to their expanded state,
the ends of the stent retaining sleeves will often likewise expand
and may also be configured to retract off of the stent ends. In the
present invention, the sleeves 22 have a unique construction which
allows a first portion 24 of the sleeve which overlies the stent 16
to attain a radial expansion of up to or exceeding 400 percent. The
second portion 26 of the sleeve 22 is disposed about and is engaged
to a portion of the catheter shaft 14 adjacent to the balloon 12.
Because the second portion 26 is not typically subjected to an
expansive force its radial expansion is minimal. When the sleeve is
expanded, the sleeve undergoes minimal or no increase in
length.
[0033] As stent 16 is expanded, the stent ends 18 and 20 will
eventually be drawn from underneath the stent retaining sleeves 22.
The present sleeves 22 may expand to nearly the same extent as the
balloon 12 thereby ensuring the position of the stent 16 on the
catheter 14. By providing a sleeve 22 which may control the time of
the release of the stent 16 during the expansion procedure, the
present invention ensures that the stent is delivered in an
extremely accurate and consistent manner.
[0034] The sleeves 22 are capable of expanding in the manner
described as a result of their unique construction. As previously
indicated, the sleeves 22 are constructed from at least two
materials having different tensile modulus characteristics. The
first material 30 is formed into a generally tubular body 32 which
provides the sleeve with its shape. The second material 34 is
embodied in at least one substantially longitudinally oriented
fiber or filament 36.
[0035] The first material may be any elastic material known.
Preferably the durometer hardness of the first material is between
40A and 100A. The second material 34 may be any material that when
presented as one or more longitudinally oriented fibers has a
tensile modulus greater than that of the first material.
[0036] In the embodiment shown in FIG. 1, the fiber 36 may extend
substantially across the longitudinal length of the sleeve 22, the
material 34 of fiber 36 will tend to provide a greater restriction
on longitudinal expansion compared to radial expansion of the
sleeve as has been previously described.
[0037] The first material 30 may be selected from one or more of
the following substances: polyurethane-polyether polymers, such as
Tecothane.TM. 1074A available from Thermedics, Inc.;
polyester-polyurethanes, such as Pellethane.TM. 2103-70A sold by
Dow Chemical; polyether-polyurethanes, such as Estane.TM. 5703P
sold by BF Goodrich; polyether block amides, such as Pebax.TM. 2533
available from Elf Atochem; and styrene-butadien-styrene triblock
copolymers such as Kraton.TM. D1101 sold by Shell Chemical company.
Other materials which may also be used in the production of the
first material 30 include, but are not limited to styrenic block
copolymers, polyurethanes, silicone rubber, natural rubber,
copolyesters, polyamides, EPDM rubber/polyolefin, nitril
rubber/PVC, fluoroelastomers, butyl rubber, epichlorohydrin, and
any combinations thereof.
[0038] The second material 34 may be selected from one or more of
the following substances: metal, glass, carbon, and/or
polymers.
[0039] Where the material 34 includes a polymer, such polymer
materials may be a liquid crystal polymer (LCP) such as VECTRA.TM.
LKX 1107, 1111, polyetheretherketone (PEEK) material, and PPS.
Other materials may also be utilized as the fibril component of the
present invention. Such substances include aromatic nylon, rigid
polyurethane, polyester, copolyester, polyester blends,
polyester/polyurethane blends, PEEK, PPS, fluoropolymer and so
on.
[0040] Fiber(s) 36 may also include one or more of the following
substances: polyurethane-polyether polymers, such as Tecothane.TM.
1055D or 1065D both of which are available from Thermedics, Inc.;
polyether-polyurethanes, such as Estane.TM. 58237 sold by BF
Goodrich; polyether block amides, such as Pebax.TM. 7233 or 6333
both of which are available from Elf Atochem. Other materials which
may also be used in the production of the second material 34
include, but are not limited to: polyolefins, polystyrene,
polyvinyl chloride, acrylonitrile-butadiene-sty- rene polymers,
polyacrylonitrile, polyacrylate, vinyl acetate polymer, cellulose
plastics, polyurethanes, polyethylene terephthalate, polyacetal,
polyethers, polycarbonates, polyamides, polyphenylene sulfide,
polyarylethersulfones, polyaryletherketones,
polytetrafluoroethylene, and any combinations thereof.
[0041] Other materials which may be suitable for use in forming
fiber(s) 36 include Nylon, Kevlar.TM., polyethyleneterephthalate
(PET), stainless steel, NITINOL and others.
[0042] The various materials which may be used to form the fiber or
fibers 36 as depicted in the various figures may be combined with
the first material 24 in a wide variety of manners and
configurations. The material 34 may combine one or more of the
materials described above into a fiber 36 such as is shown.
Alternatively, the fiber 36 may be a combination of one or more
materials woven together, or a single continuous shaft of material
or materials, such as a filament or wire of one or more of the
materials 34 mentioned above. Other configurations may also be
provided, some of which are described in greater detail below.
[0043] In addition, the manner in which the fiber(s) 36 are
combined with the first material 24 may also vary. The fiber(s) 36
may be co-extruded with the first material 24. The fiber(s) 36 may
be imbedded into the first material 24, or may be placed over the
first material 24. The fiber(s) may also be woven into the matrix
of the first material 24.
[0044] The above examples of the first and second materials 30 and
34 or the configurations of fiber(s) 36 or the various manners in
which the fiber(s) 36 and first material 24 may be joined, are in
no way exhaustive of the potential substances or combinations of
substances which may be used. The present invention is directed to
a sleeve composed of any materials which have the respective
tensile modulus qualities previously described for the respective
materials 30 and 34.
[0045] As may be seen in the various figures, the present invention
may be embodied in a variety of manners. For instance, in the
embodiment shown in FIG. 1 the catheter 10 is seen with a pair of
sleeves 22 each of which have a single longitudinally parallel
fiber 36. The fiber 36 may be a wire, or filament of material
placed onto a surface of the body 32.
[0046] As may be seen in FIG. 2, the sleeve(s) 22 may include a
plurality of fibers. The fibers 36 may be arranged in any manner
desired, for example, in FIGS. 5 and 6 the sleeve 22 includes a
plurality of fibers 36 having a variety of lengths. As may best be
seen in FIGS. 5 and 6, the fibers 36 do not need to extend the
entire length of the sleeve 22. The fibers 36 may have
significantly reduced lengths when compared to that of the sleeve
22. In addition the fibers 36 may be positioned in a uniform manner
relative to one another about the circumference 40 of the sleeve 22
such as may be seen in FIGS. 7-12, or the fibers 36 may be randomly
distributed such as is illustrated in FIGS. 5 and 6.
[0047] In FIG. 3 an embodiment of the invention is shown wherein
the sleeves 22 have fibers 36 which are tapered. Each fiber 36 has
a first end 42 and a second end 44. The first end corresponds to
the portion 24 of the sleeve 22 which overlies the end of the stent
16 and the second end 44 corresponds to the portion 26 of the
sleeve 22 which is engaged to the catheter shaft 14. The second end
44 has a predetermined width which is greater than and tapers to
the predetermined width of the first end 42. By providing the
portion 26 of the sleeve 22 with a proportionally stronger second
material 34 than the first portion 24, the second portion will have
a greater resistance to expansion and will therefor remain engaged
to the shaft 14 through out most of the stent delivery procedure.
At the same time the comparatively reduced amount of second
material 34 at or near the first portion of the sleeve 22, will
allow the first portion 24 to more readily and fully expand
according to the expansion characteristics of the first material
30, as previously described.
[0048] FIGS. 4-6 show additional configurations of the fiber 36 as
it may be embodied on a sleeve 22 design. FIG. 4 shows a sleeve 22
which includes a plurality of fibers 36 having a sinusoidal
configuration. FIGS. 5 and 6, shows a sleeve 22 having fibers 36
with a variety of lengths and configurations. Other arrangements
may also be provided.
[0049] As previously discussed the fibers 36 may be applied to or
combined with the body 32 in a variety of manners. For instance
where the second material 34 is a coating, the fiber(s) 36 may be
directly applied to a surface of the sleeve 22, in any of the
patterns or configurations discussed thus far. In the embodiments
shown in FIGS. 7-12 a variety of additional fiber 36 and body 32
arrangements are shown.
[0050] In FIGS. 7 and 8, the sleeve 22 has a predetermined
thickness 48. The body 32 and fibers 36 which make up the sleeve 22
have the same uniform thickness 48 through out the entire sleeve
22. Such an arrangement may be possible by forming the sleeve 22
directly via a co-extrusion process, or by bonding uniformly thick
pieces of alternating materials together.
[0051] In FIGS. 9 and 10 an embodiment of the sleeve 22 is shown
wherein the fibers 36 are raised relative to the thickness 48 of
the body 32. While the thickness of the fibers 36 may be the same
or different than that of the body 32, the fibers have a raised
appearance because they are positioned in longitudinal grooves 50
positioned longitudinally about the circumference 40 of the sleeve
22. Such a `raised fiber` may provide for fiber(s) of greater
hardness which in turn provides for greater sleeve stiffness. In
the embodiment shown in FIGS. 11 and 12, the grooves 50 are also
present but the fibers 36 are not raised thereby providing the
entire sleeve 22 with a uniform thickness as well as a reduced
profile relative to the fiber configurations shown in FIGS. 9 and
10.
[0052] It should also be noted that the fibers 36 such as are
depicted in FIGS. 9-12 may be raised relative to the inside of the
sleeve, such that the fibers 36 extend radially inward relative to
the thickness 48 of the body 32.
[0053] In alternative embodiments, notably those utilized
specifically for delivery of a self expanding stent, a retractable
sheath (not shown) such as are known in the art, may be employed to
overlay the stent. In such embodiments a single sleeve or two
sleeves such have been shown and described may be employed to
retain the self-expanding stent in place. When the sheath is
retracted the stent will expand causing the sleeve(s) to
retract.
[0054] In addition to being directed to the embodiments described
above and claimed below, the present invention is further directed
to embodiments having different combinations of the features
described above and claimed below. As such, the invention is also
directed to other embodiments having any other possible combination
of the dependent features claimed below.
[0055] The above examples and disclosure are intended to be
illustrative and not exhaustive. These examples and description
will suggest many variations and alternatives to one of ordinary
skill in this art. All these alternatives and variations are
intended to be included within the scope of the attached claims.
Those familiar with the art may recognize other equivalents to the
specific embodiments described herein which equivalents are also
intended to be encompassed by the claims attached hereto.
* * * * *