U.S. patent application number 09/898741 was filed with the patent office on 2002-01-17 for stent securement by balloon modification.
Invention is credited to Hanson, Scott M., Pederson, Gary J. JR., Seppala, Jan D..
Application Number | 20020007192 09/898741 |
Document ID | / |
Family ID | 23311450 |
Filed Date | 2002-01-17 |
United States Patent
Application |
20020007192 |
Kind Code |
A1 |
Pederson, Gary J. JR. ; et
al. |
January 17, 2002 |
Stent securement by balloon modification
Abstract
Improved stent securement in a balloon catheter including
balloon modification.
Inventors: |
Pederson, Gary J. JR.;
(Maple Grove, MN) ; Seppala, Jan D.; (Maple Grove,
MN) ; Hanson, Scott M.; (Columbia Heights,
MN) |
Correspondence
Address: |
VIDAS, ARRETT & STEINKRAUS, P.A.
6109 BLUE CIRCLE DRIVE
SUITE 2000
MINNETONKA
MN
55343-9185
US
|
Family ID: |
23311450 |
Appl. No.: |
09/898741 |
Filed: |
July 3, 2001 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
09898741 |
Jul 3, 2001 |
|
|
|
09335361 |
Jun 17, 1999 |
|
|
|
6280412 |
|
|
|
|
Current U.S.
Class: |
606/192 ;
604/103.07; 604/916 |
Current CPC
Class: |
A61F 2/958 20130101;
A61F 2002/9583 20130101 |
Class at
Publication: |
606/192 ;
604/103.07; 604/916 |
International
Class: |
A61M 029/00 |
Claims
What is claimed is:
1. In a stent-carrying balloon catheter in which a balloon is
positioned within a stent for expanding the stent upon dilation of
the balloon, the improvement comprising a circumferential fold in
the balloon body over a portion of the balloon itself, the fold
including first and second layers of balloon material which are
touching each other in a plurality of location, the fold
encompassing a circumferential end portion of the stent for
securing it in place until dilation of the balloon.
2. The improvement of claim 1 in which the fold is in the region of
at least one end portion of the balloon.
3. The improvement of claim 1 in which there are two folds in the
balloon one each encompassing an end respectively of the stent.
4. The improvement of claim 3 in which the two folds are in the
region of opposite ends of the balloon.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation application of
application Ser. No. 09/335,361, filed Jun. 17, 1999, the contents
of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] This invention relates to improved apparatus suitable for
stent delivery and implantation.
[0003] Stents are implantable devices which are placed within body
lumens and the like, such as blood vessels. Stents are typically
tubular in form, the diameter of which can be increased for
implantation. They maybe made of plastic or metal. Stents are
usually introduced for implantation percutaneously by means of a
catheter and the diameter of the stent is increased by inflation of
a balloon on the catheter.
[0004] In one aspect, this invention relates to an improvement in
the stent delivery system described in U.S. Pat. No. 4,950,227 to
Savin et al., entitled "Stent Delivery System" and issued on Aug.
21, 1990. This patent is incorporated herein in its entirety by
reference.
[0005] 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.
SUMMARY OF THE INVENTION
[0006] In a first aspect, this invention provides securement of a
stent on a balloon by means of a folded or rolled end portion of
the balloon itself.
[0007] In another aspect of this invention the balloon configured
as described above is used in combination with the elastic sleeves
of the Savin et al. patent.
[0008] Additionally, the balloon shape may be modified, as by
enlarged cone portions, to facilitate the above improvements.
[0009] Moreover, these features may be used alone or in combination
and may be applied to one or both ends of the stent to secure it
for delivery.
BRIEF DESCRIPTION OF THE DRAWING(S)
[0010] FIG. 1 is an axial cross-section view of one embodiment of a
balloon catheter of the present invention, showing the catheter
operatively disposed in a body conduit.
[0011] FIG. 2 is an axial cross-section view of a balloon catheter,
the balloon being rolled or folded onto the catheter cannula to
encompass the ends of the stent carried by the balloon;
[0012] FIG. 3 is an enlarged cross-section view of one end of the
balloon of FIG. 2;
[0013] FIG. 4 is a schematic plane view of the distal end portion
of a balloon catheter having a stent fixed to the catheter by means
of folds in the balloon and retractable sleeves;
[0014] FIGS. 5, 6, 7 and 8 are schematic views showing simultaneous
expansion of a catheter balloon and stent and the resultant release
of the stent from the balloon and retaining sleeves;
[0015] FIG. 9 is a schematic showing of a balloon of modified
construction according to the invention;
[0016] FIG. 10 is an axial cross-section similar to FIG. 1 showing
the balloon of FIG. 9 on a catheter with retractable sleeves,
and
[0017] FIG. 11 is a schematic view in fragment of another
embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] A stent-carrying balloon catheter is illustrated generally
in FIG. 1 and designated by the reference numeral 10. The catheter
10 is operatively disposed in a body conduit defined by walls 11
and includes an elongate cannula 12 having a distal end 14 and a
proximal end (not shown).
[0019] Catheter 10 includes a balloon 16 (inflated) having a distal
end 18 and a proximal end 21. A central wall 27 is disposed between
end wall 18 and 21 in a central region 30 of balloon 16.
[0020] In this embodiment the end walls 18 and 21 are relatively
thick and relatively small in diameter. This is in comparison to
central wall 27 of balloon 16 which is relatively thin and
relatively large in diameter.
[0021] A pair of transition walls or cones 32 and 34 are of
particular interest to the preferred embodiment of this invention.
A stent 36 is shown on balloon 16 being expanded by the dilated
balloon.
[0022] Referring to FIGS. 2 and 3, the cones 32 and 34 of
particular interest are discussed in more detail. As can be seen in
the Figures, cone portions 32 and 34 are rolled or folded as at 32a
and 32b under or over themselves and the catheter cannula 12 to
encompass the ends 36a and 36b respectively of the stent thus
securing it to the catheter.
[0023] Upon inflation of balloon 16, folds 32a and 32b open to a
configuration similar to that shown in FIG. 1 to release the stent
for expansion by the balloon.
[0024] Referring to FIG. 4, a stent delivery system 10 includes a
balloon catheter 12 having a balloon 16 fixed to the catheter for
remote inflation as is known in the art. The catheter includes an
elongate cannula 46 and may include marker bands 44. Balloon 16 is
shown in a somewhat contracted state. A stent 36 is positioned
about balloon 16 on catheter 12 and held by two overlying retaining
sleeves, a proximal one 40 and a distal one 42.
[0025] Stent 36 may be of any known type. In this instance for
example it may be a balloon expandable stent of stainless steel,
such as the known types which are cut or etched from hypotubes.
[0026] Sleeves 40 and 42 may be axially fixed along catheter 12 as
by an adhesive (not shown). The sleeves overlap stent 36 at each of
the stent ends or margin 36a and 36b as shown. Additionally,
further securement of stent 36 is provided by balloon folds 32a and
32b similar to those shown in FIGS. 2 and 3.
[0027] Sleeves 40 and 42 are comprised of elastomeric polymeric
material such as rubber, urethane, styrenes, silicone,
polyurethane, polyethylene, PET, ABS and polyimides. A lubricant
additive such as silicone may be included in or on the sleeves.
Additionally, further securement of stent 16 is provided by balloon
folds 32a and 32b similar to those shown in FIGS. 2 and 3.
[0028] Referring to FIGS. 5, 6, 7 and 8, the stent delivery system
10 of FIG. 4 is inserted percutaneously by known technique into a
body lumen or the like. As the stent is positioned (FIG. 2),
balloon 16 is expanded (FIGS. 6 and 7). During balloon expansion,
stent 36 is also expanded and sleeves 40 and 42 deform elastically
while balloon folds 32a and 32b open to release the stent. The
balloon is then deflated by standard technique and catheter 12 with
sleeves 40 and 42 is axially removed leaving stent 36 implanted
(FIG. 8).
[0029] In some instances, only one sleeve may be provided at one
end in the system. Also, only one fold may be provided in the
balloon at one end. Preferably, the fold(s) are in the end regions
of the balloon but could be located anywhere to accommodate the
size stent used relative to the balloon length used.
[0030] Referring now to FIG. 9, a balloon 16 of modified
construction according to the invention is shown. Balloon 16
includes a central body portion 30 of a nominal size, distal
catheter attachment ends 18 and 21, and cone portions 32 and 34,
also in end regions of the balloon. Cone portions 32 and 34 are
larger in diameter, at least adjacent to their attachment to body
30, than the nominal body 30 size.
[0031] A purpose of this construction modification in the balloon
is to facilitate sleeve retraction as is shown in FIG. 10. As can
be seen from the Figure, when balloon 30 begins to inflate, the
enlarged cones 32 and 34 increase in size to aid in sleeve 40 and
42 retraction to expose the stent 36 for expansion upon further
inflation of the balloon.
[0032] It is contemplated within the purview of this invention that
the balloon, particularly in the region of the cones, may be
physically modified so as to change the mechanical characteristics
of the balloon in order to facilitate folding of the balloon. For
example, this may be accomplished by forming slits or other
apertures in those regions of the balloon. Sealing would be
accomplished by the balloon fold or by covering by the sleeves.
Such apertures might be formed in the balloon as made or formed in
it later. For example, when the stent is crimped to the balloon,
the stent ends maybe utilized to form apertures in the balloon
material.
[0033] Referring now to FIG. 11, which is a fragment schematic of a
catheter system similar to those of the preceding Figures, a
modified balloon construction is shown in which the stent 36 is
positioned within a raised end 16a and 16b of balloon 16.
Optionally, a dam 50 may be included as is known in the art. The
balloon will preferably include raised end portions at both ends as
shown. However, only one end, preferably the distal end 16a, could
be raised. The raised relationship may be slitted by forming it in
the balloon similar to the construction shown in FIG. 9. Rotating
sleeves may be optionally used in this embodiment.
[0034] 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.
* * * * *