U.S. patent application number 14/643474 was filed with the patent office on 2015-09-03 for delivery system and method of use for deployment of self-expandable vascular device.
This patent application is currently assigned to CAPPELLA, INC.. The applicant listed for this patent is CAPPELLA, INC.. Invention is credited to Raz BAR-ON, Michael GILMORE, Damian KELLY, Gil NAOR, Ascher SHMULEWITZ, Mark STECKEL, Menashe YACOBY.
Application Number | 20150246210 14/643474 |
Document ID | / |
Family ID | 37102141 |
Filed Date | 2015-09-03 |
United States Patent
Application |
20150246210 |
Kind Code |
A1 |
YACOBY; Menashe ; et
al. |
September 3, 2015 |
DELIVERY SYSTEM AND METHOD OF USE FOR DEPLOYMENT OF SELF-EXPANDABLE
VASCULAR DEVICE
Abstract
A delivery system for a self-expandable prosthesis includes a
catheter having a distal portion and a proximal portion, a balloon
portion positioned on the distal portion, and a self expanding
medical device positioned about the balloon portion. The medical
device has a compressed state and an expanded state. A sheath
couples the medical device in its compressed state about the
balloon portion and has only a single opening in a wall of the
sheath. When the balloon is expanded, the sheath is configured to
(i) first rupture at the single opening, thereby allowing the
medical device to self-expand and engage an inner wall of a vessel,
and (ii) controllably continue the rupturing from the single
opening to the proximal end of sheath, thereby allowing the medical
device to expand to its expanded state and a portion of the medical
device to engage an inner wall of the vessel.
Inventors: |
YACOBY; Menashe; (Shoham,
IL) ; SHMULEWITZ; Ascher; (Tel Aviv, IL) ;
BAR-ON; Raz; (Moshav Tel Adashim, IL) ; NAOR;
Gil; (Ramat-Hasharon, IL) ; KELLY; Damian;
(Galway, IE) ; GILMORE; Michael; (Galway, IE)
; STECKEL; Mark; (Sharon, MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CAPPELLA, INC. |
Auburndale |
MA |
US |
|
|
Assignee: |
CAPPELLA, INC.
Auburndale
MA
|
Family ID: |
37102141 |
Appl. No.: |
14/643474 |
Filed: |
March 10, 2015 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
11457621 |
Jul 14, 2006 |
|
|
|
14643474 |
|
|
|
|
60699151 |
Jul 14, 2005 |
|
|
|
Current U.S.
Class: |
604/509 ; 29/450;
604/103.05 |
Current CPC
Class: |
A61F 2230/0054 20130101;
A61F 2/958 20130101; A61F 2/97 20130101; A61F 2/915 20130101; A61F
2/88 20130101; A61M 25/10 20130101; A61F 2/9522 20200501; A61F
2002/91525 20130101; Y10T 29/4987 20150115; A61F 2/844 20130101;
A61F 2250/0039 20130101; A61F 2002/9583 20130101; A61F 2002/91558
20130101; A61F 2/966 20130101; A61F 2230/005 20130101; A61F
2002/821 20130101; A61M 25/1034 20130101; A61M 2025/1081 20130101;
A61F 2002/91533 20130101; A61F 2/91 20130101 |
International
Class: |
A61M 25/10 20060101
A61M025/10 |
Claims
1. A delivery system for a self expanding medical device,
comprising: a catheter having a distal portion and a proximal
portion; a balloon portion positioned on the distal portion of the
catheter; a self expanding medical device positioned about the
balloon portion, the medical device having a compressed state and
an expanded state; and a sheath coupling the medical device in its
compressed state about the balloon portion, the sheath having a
proximal end and a distal end, the sheath having only a single
opening in a wall of the sheath between the proximal end and the
distal end, wherein, when the balloon is expanded, the sheath is
configured to (i) first rupture at the single opening, thereby
allowing the medical device to self-expand and engage an inner wall
of a vessel, and (ii) controllably continue the rupturing from the
single opening to the proximal end of sheath, thereby allowing the
medical device to expand to its expanded state and a portion of the
medical device to engage an inner wall of the vessel.
2. The delivery system of claim 1, wherein the single opening is
configured to provide an initial direction of separation of the
sheath.
3. The delivery system of claim 1, wherein the single opening is at
the distal end of the sheath.
4. The delivery system of claim 3, wherein the single opening is a
cut extending longitudinally from the distal end of the sheath.
5. The delivery system of claim 4, wherein the cut extends not more
than approximately 5% of a length of the sheath.
6. The delivery system of claim 1, wherein the single opening
extends longitudinally relative to the sheath.
7. The delivery system of claim 1, wherein the proximal end of the
sheath is attached to the catheter at a location on the catheter
proximal to the balloon portion such that the sheath remains
attached to the catheter after the rupturing.
8. The delivery system of claim 1, wherein the sheath is configured
to remain in the vessel after the catheter is removed from the
vessel.
9. A method of inserting a self expanding medical device into a
vessel, the method comprising: providing a delivery system
comprising: a catheter having a distal portion and a proximal
portion; a balloon portion positioned on the distal portion of the
catheter; a self expanding medical device positioned about the
balloon portion, the medical device having a compressed state and
an expanded state; and a sheath coupling the medical device in its
compressed state about the balloon portion, the sheath having a
proximal end and a distal end, the sheath having only a single
opening at the distal end of the sheath; inserting the catheter
into the vessel; expanding the balloon portion such that the sheath
is first ruptured at the single opening, thereby allowing the
medical device to self-expand and engage an inner wall of the
vessel; controllably continuing the rupturing of the sheath from
the single opening to the proximal end of sheath, thereby allowing
the medical device to expand to its expanded state and a portion of
the medical device engages an inner wall of the vessel; deflating
the balloon portion; and withdrawing the catheter proximally
through the expanded medical device whereby the medical device is
deployed at the desired position in the vessel.
10. The method of claim 9, wherein the step of providing a delivery
system further includes providing the single opening extending
longitudinally relative to the sheath such that, when the sheath is
first ruptured at the single opening, the single opening provides
an initial direction of separation of the sheath.
11. The method of claim 9, wherein the step of providing a delivery
system further includes providing the single opening at the distal
end of the sheath.
12. The method of claim 11, wherein the step of providing the
single opening includes providing a cut extending longitudinally
from the distal end of the sheath not more than approximately 5% of
a length of the sheath.
13. The method of claim 9, wherein the sheath remains in the vessel
after the catheter is removed from the vessel.
14. The method of claim 9, wherein the proximal end of the sheath
is attached to the catheter at a location on the catheter proximal
to the balloon portion and remains attached to the catheter after
the rupturing such that the sheath is withdrawn from the vessel
with the catheter.
15. A method of making a delivery system for a self expanding
medical device, the method comprising: providing a catheter having
a distal portion and a proximal portion; positioning a balloon
portion on the distal portion of the catheter; positioning a self
expanding medical device about the balloon portion, the medical
device having a compressed state and an expanded state; providing a
sheath having a proximal end and a distal end; forming only a
single opening in a wall of the sheath between the proximal end and
the distal end; and coupling the medical device in its compressed
state about the balloon portion with a sheath, when the balloon is
expanded, the sheath is configured to (i) first rupture at the
single opening, thereby allowing the medical device to self-expand
and engage an inner wall of a vessel, and (ii) controllably
continue the rupturing from the single opening to the proximal end
of sheath, thereby allowing the medical device to expand to its
expanded state and a portion of the medical device to engage an
inner wall of the vessel.
16. The method of claim 15, wherein the step of forming the single
opening comprises forming the single opening extending
longitudinally relative to the sheath such that, when the sheath is
first ruptured at the single opening, the single opening is
configured to provide an initial direction of separation of the
sheath.
17. The method of claim 15, wherein the step of forming the single
opening comprises forming the single opening at the distal end of
the sheath.
18. The method of claim 17, wherein the step of forming the single
opening comprises forming a cut extending longitudinally from the
distal end of the sheath not more than approximately 5% of a length
of the sheath.
19. The method of claim 15, wherein the sheath is configured to
remain in the vessel after the catheter is removed from the
vessel.
20. The method of claim 15, further comprising attaching the
proximal end of the sheath to the catheter at a location on the
catheter proximal to the balloon portion such that the sheath
remains attached to the catheter after the rupturing.
Description
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 11/457,621, filed Jul. 14, 2006, pending, which claims priority
to U.S. Provisional Patent Application No. 60/699,151, filed Jul.
14, 2005, the entire contents of both of which are hereby
incorporated by reference.
FIELD OF THE INVENTION
[0002] The present disclosure relates to a delivery system and
method for deployment of a vascular device and, more particularly,
to a delivery system and method for deployment of a self-expanding
vascular device.
BACKGROUND OF THE INVENTION
[0003] Tubular prostheses typically fall into two general
categories of construction. The first category of prosthesis is
expandable upon application of a controlled force, often through
the inflation of the balloon portion of a dilatation catheter,
which expands the compressed prosthesis to a larger diameter to be
left in place within a vessel, e.g., an artery, at the target site.
The second category of prosthesis is a self-expanding prosthesis
formed from, for example, shape memory metals or super-elastic
Nickel-Titanium (NiTi) alloys, that will automatically expand from
a compressed state when the prosthesis is advanced out of the
distal end of the delivery catheter into the blood vessel.
[0004] Some known prosthesis delivery systems for implanting
self-expanding stents include an inner lumen upon which the
compressed or collapsed prosthesis is mounted and an outer
restraining sheath that is initially placed over the compressed
prosthesis prior to deployment. When the prosthesis is to be
deployed in the body vessel, the outer sheath is moved in relation
to the inner lumen to "uncover" the compressed prosthesis, allowing
the prosthesis to move to its expanded condition. Some delivery
systems utilize a "push-pull" design and technique in which the
outer sheath is retracted while the inner lumen is pushed forward.
Still other systems use an actuating wire that is attached to the
outer sheath. When the actuating wire is pulled to retract the
outer sheath and deploy the prosthesis, the inner lumen must remain
stationary, to prevent the prosthesis from moving axially within
the body vessel.
[0005] There have been, however, problems associated with these
delivery systems. Systems that use the "push-pull" design can
experience movement of the collapsed prosthesis within the body
vessel when the inner lumen is pushed forward. This movement can
lead to inaccurate positioning and, in some instances, possible
perforation of the vessel wall by a protruding end of the
prosthesis. Further, systems that utilize the actuating wire design
will tend to move to follow the radius of curvature when placed in
curved anatomy of the patient. As the wire is actuated, tension in
the delivery system can cause the system to straighten. As the
system straightens, the position of the prosthesis changes because
the length of the catheter no longer conforms to the curvature of
the anatomy. This change of the geometry of the system within the
anatomy also leads to inaccurate prosthesis positioning.
[0006] Systems are known for delivering or implanting a
self-expanding device in a vessel by operation of a balloon to
rupture a sheath that holds the self-expanding device in a
compressed state. When the device is located at the desired
position in the vessel, the balloon is inflated, rupturing the
sheath, thereby allowing the device to expand into position.
Examples of these systems include U.S. Pat. No. 6,656,213 to Solem
and U.S. Pat. No. 5,549,635 to Solar.
[0007] While Solem '213 and Solar '635 describe systems for
delivering a self-expanding stent by operation of a balloon to
rupture a sheath, experimental implementations of systems of these
types of systems have shown results that fall short of
expectations. In experiments on porcine coronary arteries,
withdrawal of the catheter delivery system after sheath rupturing
resulted in migration of the stent from the target implant
position. The amount of stent migration was unpredictable and was
in the range of 3-10 mm, which is suboptimal for the treatment of
coronary lesions.
[0008] There are two primary structural factors that lead to stent
migration for these systems. First the stent may remain
circumferentially enclosed by the sheath at points along its length
even after sheath rupture, i.e., the stent may not fully exit the
sheath. Secondly, the friction between the sheath and the stent
during catheter removal may drag the stent proximally. The
inability of these systems to offer accurate placement of a stent
at a target site causes this approach to be not optimum for
treatment of coronary lesions and similar stenotic disease
states.
[0009] There is thus a widely recognized need for, and it would be
highly advantageous to have, a delivery system that is devoid of
the above limitations.
SUMMARY OF THE INVENTION
[0010] According to one aspect of the present invention there is
provided a delivery system for a self-expanding prosthesis,
comprising: a catheter having a distal portion and a proximal
portion; a balloon portion positioned near the distal portion of
the catheter; a self-expanding device having a compressed state and
an expanded state positioned about the balloon portion; and a
sheath coupling the device in its compressed state about the
balloon portion, the sheath having a proximal end and a distal end,
the proximal end of the sheath fixed to the catheter at a location
on the catheter proximal to the balloon portion, wherein the
self-expanding device comprises a flared portion and a stem portion
that, in the expanded state, expand, respectively, to a first
diameter and a second diameter, the first diameter being larger
than the second diameter, and wherein the self-expanding device is
oriented about the balloon portion such that the flared portion is
oriented toward the proximal portion of the catheter and the stem
portion is oriented toward the distal portion of the catheter.
[0011] According to another aspect of the present invention, there
is provided a method of inserting a self expanding ostial
protection device (OPD) into a side branch vessel from a main
branch vessel at an ostium, the method comprising: providing an OPD
delivery system comprising: a catheter having a distal portion and
a proximal portion; a balloon portion positioned on the distal
portion of the catheter; a self expanding OPD having a compressed
state and an expanded state positioned about the balloon portion;
and a sheath coupling the OPD in its compressed state about the
balloon portion, the sheath having a proximal end and a distal end,
the distal end fixed to the catheter at a location on the catheter
distal to the balloon portion. Further, inserting the catheter into
a side branch vessel, from a main branch vessel, to a desired
position in the side branch vessel; expanding the balloon portion
such that the sheath is ruptured and the OPD is allowed to expand
to its expanded state and a portion of the OPD engages an inner
wall of the side branch vessel; deflating the balloon portion;
inserting the catheter distally further into the side branch vessel
a distance sufficient to remove the ruptured sheath from between
the expanded OPD and the side branch vessel wall; and withdrawing
the catheter proximally through the expanded OPD whereby the OPD is
deployed at the desired position in the side branch vessel.
[0012] According to another aspect of the present invention, there
is provided a method of inserting a self expanding ostial
protection device (OPD) into a side branch vessel from a main
branch vessel at an ostium, the method comprising: providing an OPD
delivery system comprising: a catheter having a distal portion and
a proximal portion; a balloon portion positioned on the distal
portion of the catheter; a self expanding OPD having a compressed
state and an expanded state positioned about the balloon portion;
and a sheath coupling the OPD in its compressed state about the
balloon portion, the sheath having a proximal end and a distal end,
the proximal end fixed to the catheter at a location on the
catheter proximal to the balloon portion, wherein the
self-expanding OPD comprises a flared portion and a stem portion
that, in the expanded state, expand, respectively, to a first
diameter and a second diameter, the first diameter being larger
than the second diameter, and wherein the self-expanding OPD is
oriented about the balloon portion such that the flared portion is
oriented toward the proximal portion of the catheter and the stem
portion is oriented toward the distal portion of the catheter.
Further, inserting the catheter into a side branch vessel, from a
main branch vessel, to a desired position in the side branch
vessel; expanding the balloon portion such that the sheath is
ruptured and the OPD is allowed to expand to its expanded state and
a portion of the OPD engages an inner wall of the side branch
vessel; deflating the balloon portion; and withdrawing the catheter
proximally from the side branch vessel whereby the OPD is deployed
at the desired position in the side branch vessel and the sheath is
withdrawn from the side branch vessel.
[0013] Unless otherwise defined, all technical and scientific terms
used herein have the same meaning as commonly understood by one of
ordinary skill in the art to which this invention belongs. Although
methods and materials similar or equivalent to those described
herein can be used in the practice of the present invention,
suitable methods and materials are described below. In case of
conflict, the specification, including definitions, will control.
In addition, the materials, methods, and examples are illustrative
only and not intended to be limiting.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The invention is herein described, by way of example only,
with reference to the accompanying drawings. With specific
reference now to the drawings in detail, it is stressed that the
particulars shown are by way of example and for purposes of
illustrative discussion of the various embodiments of the present
invention only, and are presented in the cause of providing what is
believed to be the most useful and readily understood description
of the principles and conceptual aspects of the invention. In this
regard, no attempt is made to show structural details of the
invention in more detail than is necessary for a fundamental
understanding of the invention, the description taken with the
drawings making apparent to those skilled in the art how the
several forms of the invention may be embodied in practice.
[0015] In the drawings:
[0016] FIG. 1A is a longitudinal cross-sectional illustration of a
delivery system in accordance with one embodiment of the present
invention;
[0017] FIG. 1B is a transverse cross-sectional illustration of a
delivery system in accordance with the embodiment shown in FIG.
1A;
[0018] FIGS. 2A -2C are perspective illustrations of a distal end
of a catheter having a sheath and showing openings on the
sheath;
[0019] FIG. 3A is a longitudinal cross-sectional illustration of a
delivery system in accordance with another embodiment of the
present invention;
[0020] FIG. 3B is a transverse cross-sectional illustration of a
delivery system in accordance with the embodiment shown in FIG.
3A;
[0021] FIG. 4 is a cross-sectional illustration of the delivery
system of the present invention during expansion of a balloon;
[0022] FIG. 5 is a perspective view illustration of a prosthesis in
its fully expanded state, and a sheath fully open, in accordance
with an embodiment of the present invention;
[0023] FIGS. 6A-E are illustrations of steps of a method of
deployment of a prosthesis within a vessel in accordance with an
embodiment of the present invention;
[0024] FIGS. 7A-D are illustrations of steps of a method of
deployment of a prosthesis within a vessel in accordance with
another embodiment of the present invention;
[0025] FIGS. 8A-E are illustrations of steps of a method of
deployment of a prosthesis within a vessel in accordance with
another embodiment of the present invention;
[0026] FIGS. 9A-9G are illustrations of steps of a method of
deployment of a prosthesis within a vessel in accordance with
another embodiment of the present invention;
[0027] FIG. 10 is an ostial protection device;
[0028] FIG. 11 is a schematic view of an another embodiment of an
ostial protection device;
[0029] FIG. 12 is an illustration of the ostial protection device
shown in FIG. 11 located in a side branch vessel;
[0030] FIG. 13 is a cross-sectional illustration of the ostial
protection device shown in FIG. 11 as being delivered to the side
branch vessel; and
[0031] FIG. 14 is a transverse cross-sectional illustration of
another embodiment of the delivery system.
DETAILED DESCRIPTION
[0032] The present invention is directed to a delivery system for
deployment of a prosthesis in a vessel. Specifically, the present
invention can be used to deploy a self-expandable prosthesis at an
ostium or bifurcation using a balloon controllable sheath.
[0033] The principles and operation of a delivery device and
methods according to the present invention may be better understood
with reference to the drawings and accompanying descriptions.
[0034] Before explaining at least one embodiment of the present
invention in detail, it is to be understood that the invention is
not limited in its application to the details of construction and
the arrangement of the components set forth in the following
description or illustrated in the drawings. The invention is
capable of other embodiments or of being practiced or carried out
in various ways. Also, it is to be understood that the phraseology
and terminology employed herein are for the purpose of description
and should not be regarded as limiting.
[0035] It is appreciated that certain features of the invention,
which are, for clarity, described in the context of separate
embodiments, may also be provided in combination in a single
embodiment. Conversely, various features of the invention, which
are, for brevity, described in the context of a single embodiment,
may also be provided separately or in any suitable
subcombination.
[0036] Reference is now made to FIG. 1A and FIG. 1B, which are
longitudinal and transverse cross-sectional illustrations,
respectively, of a delivery system 10 in accordance with an
embodiment of the present invention. Delivery system 10 includes a
catheter 12 having a proximal end 14 and a distal end 16. The
catheter 12 has at least one guidewire lumen 18 for receiving a
guidewire 20 therethrough. In alternative embodiments, two or more
guidewire lumens 18 are provided, either coaxial with, or adjacent
to, one another. A balloon 22 is positioned on distal end 16 of
catheter 12 and is in fluid communication with an inflation lumen
23. Inflation lumen 23 runs proximally along the length of catheter
12 from balloon 22 to an inflation port 30 located at a hub 28.
Fluid, which may be a liquid or gas, is introduced into inflation
port 30, and runs through inflation lumen 23 and into balloon 22,
thereby expanding balloon 22. Such techniques are commonly known in
the art. In one embodiment, inflation lumen 23 is positioned
coaxially with respect to catheter 12, but may also be adjacent
thereto. Guidewire lumen 18 has an exit port 21 at a proximal end
thereof. In one embodiment, exit port 21 is positioned relatively
close to a proximal end of balloon 22 for rapid exchange
capabilities. In an alternative embodiment, exit port 21 is located
at proximal end 14 of catheter 12.
[0037] A self-expandable prosthesis 24 is positioned around balloon
22 in a collapsed state and is held in place, or coupled thereto,
by a sheath 26 at least partially surrounding prosthesis 24. In one
embodiment, self-expandable prosthesis 24 is comprised of a shape
memory metal or super-elastic Nickel Titanium alloy such as
Nitinol.TM.. In alternative embodiments, prosthesis 24 has elastic
properties due to design characteristics such as the use of
spring-like connectors. In general, prosthesis 24 is designed to
self-expand in the absence of a retaining element such as sheath
26. As shown in FIG. 1A and FIG. 1B, prosthesis 24 is sandwiched
between balloon 22 and sheath 26. Sheath 26 includes a
prosthesis-enclosing portion 36 and a catheter-enclosing portion
38. While the catheter-enclosing portion 38 is shown proximal to
the balloon 22, the catheter-enclosing portion 38 can also be
located distal to the balloon 22.
[0038] Expansion of balloon 22 results in a controlled separation,
and thus opening, of prosthesis-enclosing portion 36 of sheath 26.
Once prosthesis-enclosing portion 36 of sheath 26 opens, prosthesis
24 is released and is free to self-expand. In one embodiment,
catheter-enclosing portion 38 of sheath 26 remains at least
partially attached to catheter 12 after opening, at either of a
location proximal or distal to the balloon 22, and sheath 26 is
removed along with catheter 12 from the body. In another
embodiment, prosthesis-enclosing portion 36 of sheath 26 completely
detaches from catheter 12 and remains in the vessel with prosthesis
26, as will be described in further detail hereinbelow.
[0039] Reference is now made to FIGS. 2A-2C, which are perspective
illustrations of distal end 16 of catheter 12 showing sheath 26 in
accordance with various embodiments of the present invention.
Sheath 26 includes at least one opening or cut or tear 32 for
providing an initial direction of separation of the sheath 26 upon
balloon expansion. When balloon 22 is expanded, separation or
opening of sheath 26 begins at a location defined by at least one
opening 32. In some embodiments, more than one opening 32 is used.
In one embodiment, at least one opening 32 is positioned at a
distal end 25 of sheath 26, as shown in FIG. 2A. The at least one
opening 32, in one embodiment, is a cut extending longitudinally
from the distal end 25 of the sheath. In one embodiment, the cut
extends not more than approximately 5% of the length of the sheath
26. In this embodiment, separating of sheath 26 originates at
distal end 25, and a proximal end 29 of prosthesis-enclosing
portion 36 of sheath 26 remains attached to catheter 12. In an
alternate embodiment, separation of sheath 26 originates at the
proximal end 29 and the distal end 25 of prosthesis enclosing
portion 36 of sheath 26 remains attached to catheter 12. After
deployment of prosthesis 24, sheath 26 is removed along with
catheter 12.
[0040] In accordance with an embodiment of the present invention,
sheath 26 is comprised of, or coated with on either, or both of, an
inner and outer surface, a low friction material, such as, but not
limited to, for example, Teflon.TM., polytetrafluoroethylene
(PTFE), fluorinated ethylene propylene (FEP), PFA, ETFE, or any
synthetic hydrogel polymer including formulations based on HEMA,
PVP, PEG and similar compounds, or other low friction biocompatible
materials. The provision of such low-friction materials is to
facilitate that sheath 26 can be pulled out from between prosthesis
26 and the vessel wall without becoming permanently trapped,
without damaging either prosthesis 24 or the vessel wall, and
without displacing or moving the prosthesis 24 from its intended
location.
[0041] In another embodiment, at least one opening 32 is positioned
at proximal end 29 of prosthesis-enclosing portion 36 of sheath 26,
as shown in FIG. 2B. In this embodiment, separation of sheath 26
originates at proximal end 29 of prosthesis-enclosing portion 36.
Most of sheath 26 detaches from catheter 12, and remains after
deployment of prosthesis 24. In one embodiment,
prosthesis-enclosing portion 36 of sheath 26 is comprised of a
biodegradable material, such as a biodegradable polymer, so that it
can safely disintegrate over time within the body.
[0042] In alternative embodiments, several openings 32 and
locations for openings 32 are used. For example, a combination of
the distal and proximal openings 32 described above with respect to
FIGS. 2A and 2B may be used, allowing for origination of separation
at distal end 25 and detachment of sheath 26 from catheter 12. Any
other combination of openings is possible, and openings may further
have various geometric configurations, allowing for a high degree
of control over the opening of sheath 26. The several openings 32
may be located in the surface of the sheath 26 such that upon
inflation of the balloon 22, as discussed, the sheath 26 separates
but remains attached to the catheter 12. In one embodiment, the
several openings 32 may be located proximally, similar to that
shown in FIG. 2B, where the sheath 26 remains attached to the
catheter 12 at a distal end thereof. Further, in one embodiment of
the present invention the several openings 32 are provided such
that the sheath 26, upon separation, results in multiple sections
remaining attached to the catheter 12 similar to petals on a
flower.
[0043] In an alternate embodiment, as shown in FIG. 2C, at least
one opening 32 is offset a predetermined distance from the distal
end 25 of the sheath. In this embodiment, the opening 32
facilitates the separation or tearing of the sheath 26
longitudinally toward each of the distal end 25 and the proximal
end 29 upon expansion of the balloon 22.
[0044] Reference is now made to FIG. 3A and FIG. 3B, which are,
respectively, longitudinal and transverse cross-sectional
illustrations of delivery system 100 in accordance with another
embodiment of the present invention. Delivery system 100 includes
catheter 12 with proximal end 14 and distal end 16. Catheter 12 has
at least one guidewire lumen 18 for receiving guidewire 20
therethrough. In alternative embodiments, two or more guidewire
lumens 18 are provided, either coaxial with, or adjacent to, one
another. Balloon 22 is positioned on distal end 16 of catheter 12,
and is in fluid communication with inflation lumen 23. Inflation
lumen 23 runs proximally along the length of catheter 12 from
balloon 22 to inflation port 30 located at hub 28. Fluid introduced
through inflation port 30 runs through inflation lumen 23 and into
balloon 22, thereby expanding balloon 22. Fluid may be liquid or
air, and such configurations are commonly known in the art. In one
embodiment, inflation lumen 23 is positioned coaxially with respect
to catheter 12, but may also be adjacent thereto. Guidewire lumen
18 has an exit port 21 at a proximal end thereof. Exit port 21 is
located at proximal end 14 of catheter 12.
[0045] Self-expandable prosthesis 24 is positioned around balloon
22 in a collapsed state and is held in place, or coupled thereto,
by sheath 26 having a prosthesis-enclosing portion 36 and a
catheter-enclosing portion 38. In one embodiment, self-expandable
prosthesis 24 is comprised of a shape memory metal or super-elastic
Nickel Titanium alloy such as Nitinol.TM.. In alternative
embodiments, prosthesis 24 has elastic properties due to design
characteristics such as the use of spring-like connectors. In
general, prosthesis 24 is designed to self-expand in the absence of
a retaining element such as sheath 26. As shown in FIG. 3A and FIG.
3B, prosthesis 24 is sandwiched between balloon 22 and sheath
26.
[0046] Expansion of balloon 22 results in a controlled separation
of prosthesis-enclosing portion 36 of sheath 26, thereby releasing
prosthesis 24 and allowing it to expand.
[0047] In delivery system 100 shown herein, catheter-enclosing
portion 38 of sheath 26 extends proximally along the outside of
catheter 12, and has a handle 34 at a proximal end thereof. After
deployment of prosthesis 24, sheath 26 is pulled back via handle 34
prior to deflation of balloon 22 and removal of catheter 12. In
accordance with this embodiment, sheath 26 is comprised of a low
friction material, such as, for example, Teflon.TM., or other low
friction biocompatible materials, to ensure that sheath 26 can be
removed from between prosthesis 24 and the vessel wall. More
specifically, a material of sheath 26 is chosen such that the
friction between sheath 26 and prosthesis 24 is significantly lower
than the friction between prosthesis 24 and balloon 22.
Alternatively, friction-increasing elements may be added to an
outer surface of balloon 22, in order to increase the frictional
coefficient between prosthesis 24 and balloon 22.
[0048] Reference is now made to FIG. 4, which is a cross-sectional
illustration of delivery system 10 during expansion of balloon 22,
in accordance with one embodiment of the present invention. As
balloon 22 expands via fluid introduced through inflation lumen 23,
sheath 26 begins to separate, and prosthesis 24 begins to expand.
As sheath 26 separates, prosthesis 24 deploys into its fully open
state. As shown in FIG. 4, the sheath 26 is separating from its
distal end.
[0049] Reference is now made to FIG. 5, which is a perspective view
illustration of prosthesis 24 in its fully expanded state, and
sheath 26 fully separated. It should be readily apparent that
because sheath 26 is not made of an expandable material, it is
smaller than the expanded circumference of prosthesis 24 after
deployment. Thus, only a portion of prosthesis 24 is surrounded by
sheath 26 after deployment, as shown in FIG. 5. At least a portion
of sheath 26 remains located between prosthesis 24 and the vessel
wall after deployment. In a first embodiment, the remaining portion
of sheath 26 is pulled out along with catheter 12. In a second
embodiment, the remaining portion of sheath 26 remains in the
vessel. In a third embodiment, the remaining portion of sheath 26
is pulled out prior to removal of catheter 12.
[0050] Prosthesis 24 is depicted as a cylinder for illustrative
purposes only and should not be limited to this shape or
configuration. Prosthesis 24 can be any self-expandable device
which can be placed within a vessel. In one embodiment, prosthesis
24 is an ostial device as shown in FIG. 10 or such as one described
more fully in U.S. patent application Ser. No. 11/095,983, filed on
Mar. 31, 2005 and published as U.S. Publication 2005/0222672 on
Oct. 6, 2005 and which is incorporated by reference herein in its
entirety. In alternative embodiments, prosthesis 24 is any
bifurcation stent, drug coated stent, graft or any other
self-expandable vascular device.
[0051] Reference is now made to FIGS. 6A-E, which are illustrations
of steps of a method of deployment of prosthesis 24 within a vessel
in accordance with one embodiment of the present invention. First,
guidewire 20 is inserted into a main vessel 40. In one embodiment,
guidewire 20 is further advanced into a branch vessel 42, as shown
in FIG. 6A. This embodiment is useful when deploying an ostial
device into an ostium or side branch. In an alternative embodiment,
guidewire 20 is advanced through main vessel 40 for deployment of a
prosthesis at a main vessel lesion. In alternative embodiments,
more than one guidewire may be used, for example, for bifurcation
stent delivery.
[0052] Delivery system 10 is advanced over guidewire 20 until in
position, as shown in FIG. 6B. Balloon 22 is then expanded, causing
separation of sheath 26 originating at openings 32 at a distal end
of delivery system 10. This expansion of the balloon 22 causes
release of prosthesis 24 from catheter 12. Prosthesis 24 is
deployed, placing at least a portion of sheath 26 between
prosthesis 24 and a wall of branch vessel 42, as shown in FIG. 6C.
Balloon 22 is then deflated, as shown in FIG. 6D. Finally, catheter
12 with sheath 26 attached thereto is removed from the branch
vessel 42 and then from the patient via main branch 40, as shown in
FIG. 6E.
[0053] Reference is now made to FIGS. 7A-D, which are illustrations
of steps of a method of deployment of prosthesis 24 within a vessel
in accordance with another embodiment of the present invention.
First, guidewire 20 is inserted into a main vessel 40. In one
embodiment, guidewire 20 is further advanced into a branch vessel
42, as shown in FIG. 6A. This embodiment is also useful when
deploying an ostial device. In an alternative embodiment, guidewire
20 is advanced through main vessel 40 for deployment of a stent at
a main vessel lesion. In alternative embodiments, more than one
guidewire may be used, for example, for bifurcation stent
delivery.
[0054] Delivery system 10 is advanced over guidewire 20 until in
position, as shown in FIG. 7B. Balloon 22 is then expanded, causing
separation of sheath 26 originating at openings 32, shown at
proximal end 29 of prosthesis-enclosing portion 36 of sheath 26.
The expansion of balloon 22 causes release of sheath 26 from
catheter 12. Prosthesis 24 is deployed, placing at least a portion
of sheath 26 between prosthesis 24 and a wall of side vessel 42, as
shown in FIG. 7C. Balloon 22 is then deflated, and catheter 12 is
removed from the vessel, as shown in FIG. 7D. Sheath 26 remains in
the vessel, and may be comprised of either a biodegradable
material, a physiologically inert material or a combination
thereof.
[0055] Reference is now made to FIGS. 8A-E, which are illustrations
of steps of a method of deployment of prosthesis 24 within a vessel
in accordance with another embodiment method using the system 100.
First, guidewire 20 is inserted into side vessel 42 via a main
vessel 40 similar to that which has been described with reference
to FIGS. 6 and 7. Delivery system 100 is advanced over guidewire 20
until in position, as shown in FIG. 8B. Balloon 22 is then
expanded, causing separation of sheath 26 originating at openings
32 at a distal end of system 100. This expansion of the balloon 22
causes release of prosthesis 24 from catheter 12. Prosthesis 24 is
deployed, locating sheath 26 between prosthesis 24 and a wall of
side vessel 42, as shown in FIG. 8C. Sheath 26 is then pulled back
from between the prosthesis 24 and the wall of the side vessel 42,
as shown in FIG. 8D. Finally, balloon 22 is deflated, and catheter
12 and sheath 26 are removed from the main vessel 40, as shown in
FIG. 8E.
[0056] In an alternate method as shown in FIGS. 9A-9G, a method for
placing a prosthesis 24 is provided. Here, the delivery system 10
is provided with sheath 26 and openings 32 such that the sheath 26
remains attached to the catheter 12 at a point distal to the
balloon 22. As shown in FIGS. 9A and 9B, similar to that described
above with respect to FIGS. 6A and 6B, 7A and 7B and 8A and 8B, the
catheter 12 is positioned within a side vessel 42 as guided by a
guide wire 20. Upon expansion of the balloon 22, the sheath 26
separates but remains attached to the catheter 12 as shown in FIG.
9C. The separation of the sheath 26 allows the self-expanding
device 24 to expand as shown in FIG. 9D.
[0057] Subsequently, as shown in FIG. 9E, the balloon 22 is
deflated and the catheter 12 is then advanced further, in the
direction shown by the arrow D, into the side vessel 42. The
separated sheath 26 is removed from between the expanded prosthesis
24 and a wall of the side vessel 42 upon the movement of the
catheter further into the side vessel 42. Where the prosthesis 24
is an ostial device, advantageously, the insertion of the catheter
12 further into the side vessel 42 and the subsequent removal of
the sheath 26 from between the prosthesis 24 and the wall of the
side vessel 42 may operate to better position the device 24 at the
ostium.
[0058] Once the catheter 12 has been moved into the side vessel 42
a sufficient distance, i.e., a distance sufficient to remove the
sheath 26 from between the prosthesis 24 and wall of the side
vessel 42, the catheter 12 is then withdrawn back through the now
expanded prosthesis 24. As shown in FIG. 9F, this movement, as
represented by the arrow P back through the prosthesis 24, causes
the sheath 26 to orient itself so as to follow along back through
the prosthesis 24. The sheath 26, with reference to FIG. 9G, then
trails along behind the balloon 22 portion of the catheter 12 as
the catheter 12 is withdrawn in the direction shown by arrow P.
[0059] In another embodiment of the present invention, the
prosthesis being delivered by the above-described delivery system
is a self-expandable ostial protection device (OPD) as shown in
FIG. 11. An OPD 1100 comprises a flared portion 1102 and a stem
portion 1104. The OPD 1100, similar to the prosthesis 24 described
above, may be comprised of a shape memory metal or super-elastic
nickel titanium alloy such as Nitinol.TM.. In alternative
embodiments, the OPD 1100 has elastic properties due to design
characteristics such as the use of spring-like connectors. In
general, the OPD 1100 is designed to self-expand in the absence of
a retaining element such as sheath 26. In an expanded state, the
flared portion 1102 expands to a first diameter 1106 and the stem
portion 1104 expands to a second diameter 1108 where the first
diameter 1106 is greater than the second diameter 1108. In one
embodiment, the first diameter 1106 is at least 20% larger than the
second diameter 1108 and, further, may be in a range of 20%-100%
larger.
[0060] As shown in FIG. 12, the OPD 1100 is meant to be positioned
in the side branch 42 with the stem portion 1104 distally placed
relative to the flared portion 1102 placed at the ostium to the
main vessel 40.
[0061] The method of delivery of the OPD 1100 to the side branch 42
is similar to that which has been described above with respect to
the other embodiments of the present invention. The OPD 1100 is
positioned on the catheter 12 sandwiched between balloon 22 and
sheath 26 in its compressed state. The OPD 1100 is oriented such
that the flared portion 1102 is oriented toward the proximal end 14
of the catheter 12 while the stem portion 1104 is oriented toward
the distal end 16 of the catheter 12. The sheath 26 is attached to
the catheter at a location proximal to the balloon 22. Similar to
the embodiments described above, the sheath 26 includes one or more
openings 32 located at a distal end of the sheath to facilitate
rupturing or tearing of the sheath 26.
[0062] The delivery of the OPD 1100 to the side branch 42 occurs in
a manner similar to that described above with respect to the other
embodiments of the present invention. The catheter 12 is advanced
over a guidewire 20 until located at the desired position in the
vasculature. Balloon 22 is then expanded, causing separation of
sheath 26 originating at openings 32 at a distal end of the sheath
26. This expansion of the balloon 22 causes release of the OPD 1100
from catheter 12. The OPD 1100 is deployed, placing at least a
portion of sheath 26 between the stem portion 1104 and a wall of
branch vessel 42, as shown in FIG. 13. Another portion of the
ruptured sheath 26 is spread apart by the OPD flared portion 1102,
allowing the stent to exit the sheath and engage the vessel wall.
As described above, balloon 22 is then deflated and the catheter
12, with sheath 26 attached thereto, is withdrawn from the branch
vessel 42 without migration of the position of the OPD 1100.
[0063] It has been observed that the flared portion 1102 provides
many points of contact around its periphery, points 1302, 1302'
being representative in cross-section, to reduce the surface
contact between the OPD 1100 and the sheath 26. This lifting of the
ruptured sheath from an outer surface of the OPD 1100 provides a
mechanical advantage to facilitate the removal of the sheath 26
from between the side branch vessel wall and the OPD 1100 without
moving the OPD 1100 from its desired position. Withdrawal of the
sheath 26 is thereby facilitated with accurate placement of the
device.
[0064] Thus, in contrast to what may have been expected due to the
results of the porcine experiments performed with known sheathed
systems, a prosthesis such as the OPD 1100 of the present invention
can be accurately placed in the vasculature as the movement of the
OPD 1100 due to the withdrawal of the sheath 26 is minimized. In
porcine experiments, OPDs were positioned with embodiments of the
delivery system of the present invention within 1-2 mm of the
desired location within a side branch vessel of the coronary
arteries.
[0065] Another embodiment of the present invention, with respect to
the OPD 1100 is illustrated in FIG. 14. As shown in FIG. 14, the
sheath 26 is connected to the catheter 12 at a location proximal to
the balloon and proximal to the proximal ends of the sheath 26 and
the OPD 1100. The sheath 26 extends from the proximal end of the
OPD 1100 to enclose the OPD 1100 around the balloon 22. The sheath
26, however, does not extend all the way to the distal end of the
OPD 1100. Rather, the sheath 26 covers a part of the stem portion
1104 sufficient to keep the entire stem portion 1104 from
expanding. By covering enough of the stem portion 1104, the sheath
26 prevents that portion of the OPD from self-expanding prior to
the inflation of the balloon when positioned at the desired
location.
[0066] In the embodiment shown in FIG. 14, the distal end of the
balloon 22 extends beyond the distal end of the sheath 26 to
facilitate the tearing of the sheath 26. In an alternate
embodiment, the distal end of the balloon 22 extends beyond the
distal ends of the sheath 26 and the OPD 1100 or prosthesis 24. In
yet another embodiment, the distal end of the balloon 22 extends
beyond the distal end of the sheath 26 but not beyond the distal
end of the prosthesis 24 or OPD 1100.
[0067] Similarly, at the proximal ends of the sheath 26, balloon 22
and prosthesis 24, 1100, the proximal end of the balloon may be
located proximal to the proximal ends of the sheath 26, and
prosthesis 24, 1100; located proximal to only the proximal end of
the sheath 26; located proximal to only the proximal end of the
prosthesis 24, 1100; or the proximal end of the balloon 22 may be
distally located relative to the proximal ends of the sheath 26 and
the prosthesis 24, 1100.
[0068] In alternate embodiments of that shown in FIG. 14, one or
more openings 32 may be provided in accordance with that as shown
in FIGS. 2A-2C.
[0069] As has been described above, the sheath 26 may comprise a
biodegradable material or physiologically inert material. Further,
the sheath may be coated or impregnated with a therapeutic agent
for delivery to the vessel wall at which the prosthesis 24 is
placed. A sheath 26 with a therapeutic agent therein may comprise
either a biodegradable material or an inert material. Further, the
prosthesis 24 may be a drug eluting device such as is known in the
art.
[0070] Still further, the several openings 32 provided in the
sheath 26 to facilitate the separation of the sheath 26 may vary in
size and shape and position. The openings 32 may be provided in a
pattern to cause the sheath 26 to break apart into a predetermined
number of sections of a predetermined size.
[0071] Although the invention has been described in conjunction
with specific embodiments thereof, it is evident that many
alternatives, modifications and variations will be apparent to
those skilled in the art. Accordingly, it is intended to embrace
all such alternatives, modifications and variations that fall
within the spirit and broad scope of the appended claims. All
publications, patents and patent applications mentioned in this
specification are herein incorporated in their entirety by
reference into the specification, to the same extent as if each
individual publication, patent or patent application was
specifically and individually indicated to be incorporated herein
by reference. In addition, citation or identification of any
reference in this application shall not be construed as an
admission that such reference is available as prior art to the
present invention.
* * * * *