U.S. patent application number 09/954555 was filed with the patent office on 2002-08-29 for implant delivery system with interlock.
This patent application is currently assigned to IntraTherapeutics, Inc.. Invention is credited to Lee, Nathan T., Thompson, Paul J..
Application Number | 20020120323 09/954555 |
Document ID | / |
Family ID | 25164512 |
Filed Date | 2002-08-29 |
United States Patent
Application |
20020120323 |
Kind Code |
A1 |
Thompson, Paul J. ; et
al. |
August 29, 2002 |
Implant delivery system with interlock
Abstract
An implant delivery system is disclosed. The delivery system
includes an elongated member having an implant mounting location. A
self-expandable implant is mounted at the implant mounting
location. The implant is held in a compressed orientation by a
retractable sheath. An interlock structure prevents the implant
from deploying prematurely as the sheath is retracted.
Inventors: |
Thompson, Paul J.; (New
Hope, MN) ; Lee, Nathan T.; (Golden Valley,
MN) |
Correspondence
Address: |
MERCHANT & GOULD PC
P.O. BOX 2903
MINNEAPOLIS
MN
55402-0903
US
|
Assignee: |
IntraTherapeutics, Inc.
|
Family ID: |
25164512 |
Appl. No.: |
09/954555 |
Filed: |
September 17, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09954555 |
Sep 17, 2001 |
|
|
|
09795047 |
Feb 26, 2001 |
|
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Current U.S.
Class: |
623/1.11 |
Current CPC
Class: |
A61F 2/95 20130101; A61F
2002/9583 20130101; A61F 2/91 20130101; A61F 2220/005 20130101;
A61F 2002/91541 20130101; A61F 2002/91558 20130101; A61F 2/9517
20200501; A61F 2002/9665 20130101; A61F 2/915 20130101; A61F
2002/91591 20130101 |
Class at
Publication: |
623/1.11 |
International
Class: |
A61F 002/06 |
Claims
What is claimed is:
1. An implant delivery system comprising: a catheter including an
elongated member having an implant mounting location; an expandable
implant mounted on the elongated body at the implant mounting
location, the implant being expandable from a compressed
orientation to an expanded orientation, the implant including first
and second ends; a sheath mounted on the elongated member, the
sheath being positionable in a transport position in which the
sheath covers the implant mounted at the implant mounting location,
the sheath also being positionable in a deploy position in which
the implant is exposed; the implant including a first interlock
structure and the elongated body including a second interlock
structure, the first and second interlock structures interlocking
to constrain axial movement of the implant relative to the
elongated member when the implant is at least partially within the
sheath, and the first and second interlock structures not
constraining radial expansion of the implant; one of the first and
second interlock structures including a male interlock structure
and the other of the first and second interlock structures
including a female interlock structure adapted to receive the male
interlock structure when the implant is in the compressed
orientation; the implant including a cell defining region; and at
least a portion of the first interlock structure being positioned
within 5 millimeters of the first end of the implant and within 5
millimeters of the cell defining region of the implant.
2. The implant delivery system of claim 1, wherein the implant
comprises a stent.
3. The implant delivery system of claim 1, wherein at least a
portion of the first interlock structure is positioned within 2
millimeters of the first end of the implant.
4. The implant delivery system of claim 1, wherein the elongated
body includes a radiopaque marker positioned adjacent to the
implant mounting location, and wherein the marker defines the
second interlock structure.
5. The implant delivery system of claim 1, wherein the first end of
the implant is a proximal end of the implant.
6. The implant delivery system of claim 1, wherein the implant
includes a plurality of separate first interlock structures having
at least portions positioned within 5 millimeters of the first end,
and wherein the elongated body includes a plurality of second
interlock structures for interlocking with the first interlock
structures.
7. The implant delivery system of claim 1, wherein the first
interlock structure is the male interlock structure and the second
interlock structure is the female interlock structure.
8. The implant delivery system of claim 7, wherein the male
interlock structure includes an enlargement positioned at the first
end of the implant.
9. The implant delivery system of claim 8, wherein the implant
includes a plurality of enlargements at the first end of the
implant.
10. The implant delivery system of claim 8, wherein the male
interlock structure includes a circumferential projection
positioned at the first end of the implant.
11. The implant delivery system of claim 10, wherein the implant
includes a plurality of the circumferential projections at the
first end of the implant.
12. The implant delivery system of claim 1, wherein the first
interlock structure is the female interlock structure and the
second interlock structure is the male interlock structure.
13. The implant delivery system of claim 12, wherein the implant
includes struts, and the female interlock structure includes a post
opening defined through at least one of the struts.
14. The implant delivery system of claim 13, wherein the implant
includes a plurality of the post openings.
15. The implant delivery system of claim 13, wherein the implant
includes struts, and the female interlock structure includes an
opening between the struts.
16. The implant delivery system of claim 1, wherein the first
interlock structure is within 2 millimeters of the cell defining
region of the implant.
17. The implant delivery system of claim 1, wherein the first
interlock structure is within 1 millimeter of the cell defining
region of the implant.
18. The implant delivery system of claim 1, wherein the elongated
member extends completely through the implant.
19. The implant delivery system of claim 1, wherein the cell
defining region of the implant includes a boundary defined by an
inner diameter and an outer diameter of the implant, and wherein
the first interlock structure stays generally within the boundary
after the implant has been deployed.
20. The implant delivery system of claim 1, wherein the first
interlock structure is not radially outwardly biased relative to
the cell defining region of the implant.
21. An implant delivery system comprising: a catheter including an
elongated member having an implant mounting location; an expandable
implant mounted on the elongated body at the implant mounting
location, the implant being expandable from a compressed
orientation to an expanded orientation, the implant including first
and second ends; a sheath mounted on the elongated member, the
sheath being positionable in a transport position in which the
sheath covers the implant mounted at the implant mounting location,
the sheath also being positionable in a deploy position in which
the implant is exposed; the implant including a cell defining
region, the implant also including a plurality of struts at least
some of which have terminal ends defining the first end of the
implant, the implant also including at least two enlargements
positioned at the terminal ends of the struts, the enlargements
being located within 5 millimeters of the cell defining region of
the implant; and the elongated body including receptacles that
receive the enlargements to constrain axial movement of the implant
relative to the elongated member when the implant is at least
partially within the sheath.
22. The implant delivery system of claim 21, wherein the elongated
body includes a radiopaque marker positioned adjacent to the
implant mounting location, and wherein the marker defines the
receptacles.
23. The implant delivery system of claim 21, wherein the first end
of the implant is a proximal end of the implant.
24. The implant delivery system of claim 21, wherein the
enlargements are within 2 millimeters of the cell defining region
of the implant.
25. The implant delivery system of claim 21, wherein the
enlargements are within 1 millimeter of the cell defining region of
the implant.
26. The implant delivery system of claim 21, wherein the elongated
member extends completely through the implant.
27. The implant delivery system of claim 21, wherein the cell
defining region of the implant includes a boundary defined by an
inner diameter and an outer diameter of the implant, and wherein
the enlargements stay generally within the boundary after the
implant has been deployed.
28. The implant delivery system of claim 21, wherein the
enlargements are not radially outwardly biased relative to the cell
defining region of the implant.
29. An implant delivery system comprising: a catheter including an
elongated member having an implant mounting location; an expandable
implant mounted on the elongated body at the implant mounting
location, the implant being expandable from a compressed
orientation to an expanded orientation, the implant including first
and second ends; a sheath mounted on the elongated member, the
sheath being positionable in a transport position in which the
sheath covers the implant mounted at the implant mounting location,
the sheath also being positionable in a deploy position in which
the implant is exposed; the implant including a cell defining
region and first and second ends, the implant also including at
least two female male interlock structures positioned within 5
millimeters of the first end of the implant and within 5
millimeters of the cell defining region of the implant; and the
elongated body including male interlock structures that are
received within the female interlock structures to constrain axial
movement of the implant relative to the elongated member when the
implant is at least partially within the sheath, the male and
female interlock structures not constraining radial expansion of
the implant.
30. The implant delivery system of claim 29, wherein the elongated
body includes a radiopaque marker positioned adjacent to the
implant mounting location, and wherein the marker includes the male
interlock structures.
31. The implant delivery system of claim 29, wherein the first end
of the implant is a proximal end of the implant.
32. The implant delivery system of claim 29, wherein the female
interlock structures are within 2 millimeters of the cell defining
region of the implant.
33. The implant delivery system of claim 29, wherein the female
interlock structures are within 1 millimeter of the cell defining
region of the implant.
34. The implant delivery system of claim 29, wherein the elongated
member extends completely through the implant.
35. An implant delivery system comprising: a catheter including an
elongated member having an implant mounting location; an expandable
implant mounted on the elongated body at the implant mounting
location, the implant being expandable from a compressed
orientation to an expanded orientation, the implant including first
and second ends; a sheath mounted on the elongated member, the
sheath being positionable in a transport position in which the
sheath covers the implant mounted at the implant mounting location,
the sheath also being positionable in a deploy position in which
the implant is exposed; a marker attached to the elongated member,
the marker including structure that interlocks with the implant to
constrain axial movement of the implant relative to the elongated
member when the implant is at least partially within the
sheath.
36. An implant delivery system comprising: a catheter including an
elongated member having an implant mounting location; an expandable
implant mounted on the elongated body at the implant mounting
location, the implant being expandable from a compressed
orientation to an expanded orientation, the implant including first
and second ends; a sheath mounted on the elongated member, the
sheath being positionable in a transport position in which the
sheath covers the implant mounted at the implant mounting location,
the sheath also being positionable in a deploy position in which
the implant is exposed; the implant including a first interlock
structure and the elongated body including a second interlock
structure, the first and second interlock structures interlocking
to constrain axial movement of the implant relative to the
elongated member when the implant is at least partially within the
sheath, and the first and second interlock structures not
constraining radial expansion of the implant; one of the first and
second interlock structures including a male interlock structure
and the other of the first and second interlock structures
including a female interlock structure adapted to receive the male
interlock structure when the implant is in the compressed
orientation; and at least a portion of the first interlock
structure being positioned within 5 millimeters of the first end of
the implant, and the elongated member extending through the implant
at the implant mounting location.
37. The implant delivery system of claim 36, wherein at least a
portion of the first interlock structure is positioned within 2
millimeters of the first end of the implant.
38. An implant delivery system comprising: a catheter including an
elongated member having an implant mounting location; an expandable
implant mounted on the elongated body at the implant mounting
location, the implant being expandable from a compressed
orientation to an expanded orientation, the implant including first
and second ends; a sheath mounted on the elongated member, the
sheath being positionable in a transport position in which the
sheath covers the implant mounted at the implant mounting location,
the sheath also being positionable in a deploy position in which
the implant is exposed; the implant including a first interlock
structure and the elongated body including a second interlock
structure, the first and second interlock structures interlocking
to constrain axial movement of the implant relative to the
elongated member when the implant is at least partially within the
sheath, and the first and second interlock structures not
constraining radial expansion of the implant; one of the first and
second interlock structures including a male interlock structure
and the other of the first and second interlock structures
including a female interlock structure adapted to receive the male
interlock structure when the implant is in the compressed
orientation; the implant including a cell defining region that
includes a boundary defined by an inner diameter and an outer
diameter of the implant, the first interlock structure being
configured to stay generally within the boundary after the implant
has been deployed; and at least a portion of the first interlock
structure being positioned within 5 millimeters of the first end of
the implant.
39. The implant delivery system of claim 38, wherein at least a
portion of the first interlock structure is positioned within 2
millimeters of the first end of the implant.
40. A method for deploying a self-expandable implant with a
deployment system, the deployment system including a sheath for
holding the implant in a compressed orientation, the implant
including first and second ends, the implant also including an
interlock surface positioned between inner and outer diameters of
the implant, the interlock surface being located within 5
millimeters of the first end of the implant, the method comprising:
generating relative movement between the implant and the sheath to
expose the implant; engaging the interlock surface with a retainer
as the implant is exposed to prevent the implant from prematurely
exiting the sheath; and after the implant has been exposed beyond
the interlock surface, disengaging the interlock surface from the
retainer by self-expanding the implant, wherein the interlock
surface disengages from the retainer simultaneous with the
expansion of a cell defining portion of the implant.
41. The method of claim 40, wherein the implant is a stent.
42. The method of claim 40, wherein the interlock surface is within
2 millimeters of the first end of the implant.
43. The method of claim 40, wherein the first end of the implant is
a proximal end of the implant and the second end of the implant is
a distal end of the implant.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. patent
application Ser. No. 09/795,047 entitled Implant Delivery System
with Interlock, that was filed on Feb. 26, 2001.
BACKGROUND OF THE INVENTION
[0002] 1. Field of Invention
[0003] This invention pertains to a system for delivering an
implant to a site in a body lumen. More particularly, this
invention pertains to a delivery system for a self-expandable
implant such as a stent.
[0004] 2. Description of the Prior Art
[0005] Stents are widely used for supporting a lumen structure in a
patient's body. For example, stents may be used to maintain patency
of a coronary artery, other blood vessels or other body lumen.
[0006] Stents are commonly metal, tubular structures. Stents are
passed through a body lumen in a collapsed state. At the point of
an obstruction or other deployment site in the body lumen, the
stent is expanded to an expanded diameter to support the lumen at
the deployment site.
[0007] In certain designs, stents are open-celled tubes that are
expanded by inflatable balloons at the deployment site. This type
of stent is often referred to as a "balloon expandable" stent.
Other stents are so-called "self-expanding" stents. Self-expanding
stents do not use balloons to cause the expansion of the stent. An
example of a self-expanding stent is a tube (e.g., a coil tube or
an open-celled tube) made of an elastically deformable material
(e.g., a superelastic material such a nitinol). This type of stent
is secured to a stent delivery device under tension in a collapsed
state. At the deployment site, the stent is released so that
internal tension within the stent causes the stent to self-expand
to its enlarged diameter. Other self-expanding stents are made of
so-called shape-memory metals. Such shape-memory stents experience
a phase change at the elevated temperature of the human body. The
phase change results in expansion from a collapsed state to an
enlarged state.
[0008] A delivery technique for elastically deformable stents is to
mount the collapsed stent on a distal end of a stent delivery
system. Such a system would include an outer tubular member and an
inner tubular member. The inner and outer tubular members are
axially slideable relative to one another. The stent (in the
collapsed state) is mounted surrounding the inner tubular member at
its distal end. The outer tubular member (also called the outer
sheath) surrounds the stent at the distal end.
[0009] Prior to advancing the stent delivery system through the
body lumen, a guide wire is first passed through the body lumen to
the deployment site. The inner tube of the delivery system is
hollow throughout its length such that it can be advanced over the
guide wire to the deployment site.
[0010] The combined structure (i.e., stent mounted on stent
delivery system) is passed through the patient's lumen until the
distal end of the delivery system arrives at the deployment site
within the body lumen. The deployment system may include radiopaque
markers to permit a physician to visualize positioning of the stent
under fluoroscopy prior to deployment.
[0011] At the deployment site, the outer sheath is retracted to
expose the stent. The exposed stent is now free to self-expand
within the body lumen. Following expansion of the stent, the inner
tube is free to pass through the stent such that the delivery
system can be removed through the body lumen leaving the stent in
place at the deployment site.
[0012] In prior art devices, the stent may prematurely deploy as
the outer tube is retracted. Namely, with the outer tube partially
retracted, the exposed portion of the stent may expand resulting in
the remainder of the stent being squeezed out of the outer tube.
This can result in the stent being propelled distally beyond a
desired deployment site. Also, once the stent is partially
unsheathed, it is sometimes determined that the stent placement
needs to be adjusted. With existing systems, this is difficult
since the stent has a tendency to force itself out of the sheath
thereby making adjustments difficult. What is needed is a system
that retains the stent on the catheter even when a majority of the
stent has been exposed by retraction of the sheath. What is also
needed is a system that allows a stent to be re-sheathed even after
a majority of the stent has been exposed by retraction of the
sheath.
SUMMARY OF THE INVENTION
[0013] One embodiment of the present invention relates to an
implant delivery system that provides enhanced placement control of
the implant.
[0014] A variety of advantages of the invention will be set forth
in part in the description that follows, and in part will be
apparent from the description, or may be learned by practicing the
invention. It is to be understood that both the foregoing general
description and the following detailed description are exemplary
and explanatory only and are not restrictive of the invention as
claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a side elevation view of a stent delivery system
according to the present invention;
[0016] FIG. 2A is an enlarged cross-sectional view of detail A of
FIG. 1 with the stent in a compressed orientation;
[0017] FIG. 2B is an enlarged cross-sectional view of detail A of
FIG. 1 with the stent in a deployed (i.e., expanded)
orientation;
[0018] FIG. 3 is an enlarged cross-sectional view of detail B of
FIG. 1;
[0019] FIG. 4 is an enlarged cross-sectional view of detail C;
[0020] FIG. 5 is a cross-sectional view of the inner and outer
tubular members of the stent delivery system of FIG. 1 taken along
section line 5-5 of FIG. 3;
[0021] FIG. 6A is a plan view of a first stent having an interlock
structure that interlocks with an interlock structure of a mating
collar, the stent and the collar are shown cut longitudinally and
laid flat with an axial separation between the stent proximal end
and the mating collar;
[0022] FIG. 6B is the view of FIG. 6A with the stent proximal end
and mating collar shown interlocked;
[0023] FIG. 6C is an end view of the stent of FIGS. 6A and 6B in
its tubular configuration;
[0024] FIG. 7 is a laid flat, plan view of a second stent having an
interlock structure that interlocks with an interlock structure of
a mating collar, the collar includes rotational positioning
indicators;
[0025] FIG. 8 is a laid flat, plan view of a third stent having an
interlock structure that interlocks with an interlock structure of
a mating collar, the collar includes rotational positioning
notches;
[0026] FIG. 9 is a laid flat, plan view of a fourth stent having an
interlock structure that interlocks with an interlock structure of
a mating collar, the stent and the collar include a rotational
alignment key and keyway;
[0027] FIG. 10 is a laid flat, plan view of a fifth stent having an
interlock structure that interlocks with an interlock structure of
a mating collar;
[0028] FIG. 11 is a laid flat, plan view of a sixth stent having an
interlock structure that interlocks with an interlock structure of
a mating collar;
[0029] FIG. 12 is a laid flat, plan view of a seventh stent having
an interlock structure that interlocks with rectangular posts
formed on an inner body of a catheter;
[0030] FIG. 13 is a laid flat, plan view of a eighth stent having
an interlock structure that interlocks with an interlock structure
of a mating collar;
[0031] FIG. 14A is a laid flat, plan view of a ninth stent having
an interlock structure that interlocks with outwardly projecting
line-like projections formed on the inner body of a catheter;
[0032] FIG. 14B shows the stent of FIG. 14A interlocked with the
line-like projections;
[0033] FIG. 15A is a laid flat, plan view of a tenth stent having
an interlock structure that interlocks with outwardly projecting
posts formed on the inner body of a catheter;
[0034] FIG. 15B shows the stent of FIG. 15A interlocked with the
posts; and
[0035] FIGS. 16A and 16B show another delivery system that is an
embodiment of the present invention.
DETAILED DESCRIPTION
[0036] With reference now to the various drawing figures in which
identical elements are numbered identically throughout, a
description of a preferred embodiment of the present invention will
now be provided.
[0037] With initial references to FIGS. 1-4, a stent delivery
system 10 is shown. The stent delivery system 10 is for delivery of
a stent 12 to a deployment site in a body lumen of a patient's
body. By way of non-limiting, representative example, the stent 12
may be a self-expanding stent having a construction such as that
shown in U.S. Pat. No. 6,132,461. In one non-limiting embodiment,
the stent can be made of a superelastic metal such as nitinol, or
the like. The stent 12 may also be a coil stent or any other
self-expanding stent. The stent 12 includes a proximal end 12a and
a distal end 12b. Another representative stent is shown in U.S.
patent application Ser. No. 09/765,725, filed Jan. 18, 2001 and
entitled STENT, which is hereby incorporated by reference.
[0038] The stent 12 is carried on the stent delivery system 10 in a
collapsed (or reduced diameter) state as shown in FIG. 2A. Upon
release of the stent 12 from the stent delivery system 10 (as will
be described), the stent 12 expands to an enlarged diameter (see
FIG. 2B) to abut against the walls of the patient's lumen in order
to support patency of the lumen.
[0039] The stent delivery system 10 includes an inner tubular
member 14 (i.e., also referred to as an elongated member) and an
outer tubular member 16. Both of the inner and outer tubular
members 14 and 16 extend from proximal ends 14a, 16a to distal ends
14b, 16b.
[0040] The outer tubular member 16 is sized to be axially advanced
through the patient's body lumen. The tubular member 16 is
preferably sufficiently long for the distal end 16b to be placed
near the deployment site in the patient's body lumen with the
proximal end 16a remaining external to the patient's body for
manipulation by an operator. By way of example, the outer tubular
member 16 (also referred to as a sheath) may be a braid-reinforced
polyester of tubular construction to resist kinking and to transmit
axial forces along the length of the sheath 16. The outer tubular
member 16 may be of widely varying construction to permit varying
degrees of flexibility of the outer tubular member 16 along its
length.
[0041] As shown in FIG. 3, the proximal end 16a of the outer
tubular member 16 is bonded to a manifold housing 20. The manifold
housing 20 is threadedly connected to a lock housing 22. A strain
relief jacket 24 is connected to the manifold housing 20 and
surrounds the outer tubular member 16 to provide strain relief for
the outer tubular member 16.
[0042] The inner tubular member 14 is preferably formed of nylon
but may be constructed of any suitable material. As shown in FIG.
2B, the inner tubular member 14 defines a stent attachment location
26 (i.e., a stent mounting location). The inner tubular member 14
also includes markers 27, 28 that are attached to an outer surface
of the inner tubular member 14 (e.g., by techniques such as
adhesive, heat fusion, interference fit, fasteners, intermediate
members or other techniques). The attachment location 26 is
positioned between the markers 27, 28. The radiopaque markers 27,
28 permit a physician to accurately determine the position of the
stent attachment location 26 within the patient's lumen under
fluoroscopic visualization. As will be described later in the
specification, in some embodiments, at least one of the markers 27,
28 forms a collar including a geometry that interlocks with the
stent 12 to prevent axial movement of the stent 12 relative to the
inner tubular member during transport and deployment of the stent
12. Materials for making the radiopaque marker should have a
density suitable for visualization through fluoroscopic techniques.
Exemplary materials comprise tanalum, platinum, gold, tungsten and
alloys of such metals. In some embodiments, the markers can be
coated with a radiopaque material or filled with a radiopaque
filler.
[0043] A tapered and flexible distal tip member 30 is secured to
the distal end 14b of the inner tubular member 14. The highly
flexible distal tip member 30 permits advancement of the stent
deployment system 10 through the patient's lumen and minimizes
trauma to the walls of the patient's lumen. As shown in FIG. 2B,
the inner tubular member 14 preferably extends completely through
the stent 12 when the stent 12 is mounted at the attachment
location 26.
[0044] As best shown in FIGS. 3 and 4, the inner tube 14 passes
through both the manifold housing 20 and lock housing 22. A
stainless steel jacket 32 surrounds and is bonded to the inner
tubular member 14.
[0045] At the inner tube proximal end 14a, a port housing 34 is
bonded to the stainless steel jacket 32. The port housing 34 has a
tapered bore 36 aligned with an inner lumen 38 of the tubular
member 14. The inner lumen 38 extends completely through the inner
tubular member 14 so that the entire delivery system 10 can be
passed over a guide wire (not shown) initially positioned within
the patient's lumen. Opposing surfaces of the inner and outer
tubular members 14 and 16, define a first lumen 40 (best seen in
FIG. 5). As described in U.S. patent application Ser. No.
09/765,719 filed on Jan. 18, 2001 and entitled STENT DELIVERY
SYSTEM WITH SPACER MEMBER, which is hereby incorporated by
reference, splines 18 can be provided between the inner and outer
tubular members 14 and 16.
[0046] As shown in FIG. 3, the manifold housing 20 carries an
admission port 42 for injecting a contrast media into the interior
of the manifold housing 20. The interior of the manifold housing 20
is in fluid flow communication with the first lumen 40. Discharge
ports 41 (shown in FIGS. 2A and 2B) are formed through the outer
tubular member 16 to permit contrast media to flow from the first
lumen 40 into the patient's body lumen.
[0047] As shown in FIG. 3, an O-ring 44 surrounds the stainless
steel jacket 32 between the manifold housing 20 and lock housing
22. Upon threaded connection of the manifold housing 20 to the lock
housing 22, the O-ring 44 compresses against the stainless steel
jacket 32 in sealing engagement to prevent contrast media from
flowing in any path other than through the first lumen 40.
[0048] As shown in FIGS. 1 and 3, the lock housing 22 carries a
threaded locking member (or lock nut) 46 which can be turned to
abut the stainless steel jacket 32. The lock nut 46 can be released
to free the stainless steel jacket to move axially. According, when
the lock nut 46 engages the jacket 32, the jacket 32 (and attached
inner tubular member 14) cannot move relative to the lock housing
22, manifold housing 20 or the outer tubular member 16. Upon
release of the lock nut 46, the inner tubular member 14 and outer
tubular member 16 are free to slide axially relative to one another
between a transport position and a deploy position.
[0049] First and second handles 48, 50 are secured to the lock
housing 22 and jacket 32, respectively. In the transport position
(shown in FIG. 2A), the handles 48, 50 are spaced apart and the
distal end of the outer tubular member 16 forms a sheath that
covers the stent attachment location 26 to prevent premature
deployment of the stent 12. When the handle 48 is pulled rearwardly
toward the handle 50, the outer tubular member 16 slides rearwardly
or proximally relative to the inner tubular member 14. Preferably,
the outer tubular member 16 slides rearwardly a distance sufficient
to fully expose the stent attachment location 26 and permit the
stent 12 to freely expand toward its fully expanded diameter (see
FIG. 2B). After such expansion, the stent delivery system can be
proximally withdrawn through the expanded stent and removed.
[0050] As shown in FIG. 3, the first handle 48 is rotatably mounted
on a flange 22a of the lock housing 22. The first handle 48
surrounds the stainless steel jacket 32 and is freely rotatable
about the longitudinal axis of the jacket 32 and freely rotatable
about the flange 22a. The first handle 48 is axially affixed to the
lock housing 22 such that axial forces applied to the first handle
48 are transmitted through the lock housing 22 and manifold housing
20 to the outer tubular member 16 to axially move the outer tubular
16. However, rotary action of the first handle 48 about the axis of
the stainless steel jacket 32 is not transmitted to the housings
20, 22 or to the outer tubular member 16 by reason of the free
rotation of the first handle 48 on flange 22a.
[0051] As shown in FIG. 4, the second handle 50 is mounted on an
anchor 52 that is bonded to the stainless steel jacket 32 through
any suitable means (such as by use of adhesives). The anchor 52
includes a flange 52a that is radial to the axis of the stainless
steel jacket 32. The second handle 50 is mounted on the flange 52a
and is free to rotate on the anchor 52 about the axis of the
stainless steel jacket 32. However, axial forces applied to the
handle 50 are transmitted to the stainless steel jacket 32 which,
being bonded to the inner tubular member 14, results in axial
movement of the inner tubular member 14.
[0052] With the handle construction described above, relative axial
movement between the handles 48, 50 results in relative axial
movement between the inner and outer tubular members 14, 16.
Rotational movement of either of the handles 48, 50 does not affect
rotational positioning of the inner or outer tubular members 14, 16
and does not affect axial positioning of the inner and outer tubes
14, 16.
[0053] The free rotation of the handles 48, 50 results in ease of
use for a physician who may position his or her hands as desired
without fear of interfering with any axial positioning of the inner
and outer tubular members 14, 16. The spacing between the handles
48, 50 is equal to the stroke between the transport position and
the deploy position of the tubular members 14, 16. As a result, the
spacing permits the operator to have ready visual indication of the
relative axial positioning between the inner and outer tubular
members 14, 16. This relative axial positioning can be fixed by
engaging the lock nut 46. In any such positioning, contrast media
can be injected through the admission port 42 into the chamber 40
with the contrast media flowing out of the side ports 41 into the
body lumen to permit visualization under fluoroscopy.
[0054] With stent deployment systems having premounted stents of
various axial lengths, the positioning of the second handle 50 on
the stainless steel jacket 32 can be selected at time of assembly
so that a spacing S (see FIG. 1) between the handles 48, 50
corresponds to the length of the stent 12 carried on the stent
deployment system. For example, in a preferred embodiment, the
spacing S is about 10 millimeters longer than the deployed length
of the stent. Accordingly, the user will know that the outer
tubular member 16 has been fully retracted when the handles 48, 50
have been pushed completely together to completely release the
stent 12. Also, the freely rotatable handles 48, 50 are easy to
hold from any angle without slippage. The lock nut 46 ensures that
the stent 12 will not deploy prematurely.
[0055] A concern with existing delivery systems for self-expanding
stents is control of stent delivery. For example, due to their
elastic characteristics, self-expanding stents have a tendency to
propel themselves axially outwardly from their restraining sheaths
before the sheaths have been completely retracted. When this
occurs, control of stent placement is compromised since the stent
may overshoot the desired deployment site. Further, once the stent
has been completely deployed, subsequent adjustment of the stent
deployment location can be difficult because re-sheathing typically
cannot be readily accomplished.
[0056] To address the above concerns, the delivery system 10 is
preferably equipped with an interlock configuration that constrains
relative axial movement between the stent 12 and the inner tube 14
until after the sheath 16 has been fully retracted. For example,
when the stent 12 is mounted on the inner tube 14 and restrained in
the compressed orientation by the sheath 16 as shown in FIG. 2A, a
first interlock geometry (e.g., male interlock structures 82 as
shown in FIG. 2A) located at the proximal end of the stent 12
interlocks with a second interlock geometry (e.g., female interlock
structures 84 as shown in FIG. 2A) defined by the proximal marker
27 (also referred to as a collar). The interlock geometries remain
interlocked to constrain axial movement of the stent 12 until after
the sheath has been retracted beyond a predetermined location
(e.g., the proximal-most end 12a of the stent 12). When the sheath
12 has been retracted beyond the predetermined location, the
interlock geometry of the stent 12 is allowed to expand. As the
interlock geometry of the stent expands, the interlock geometry of
the stent disengages from the interlock geometry of the marker 27
thereby allowing the inner tube 14 of the catheter to be moved
axially relative to the stent without interference from the
interlock geometries.
[0057] FIGS. 6A and 6B illustrate the proximal end 12a of the stent
12 in relation to the marker 27 located at the proximal end of the
attachment location 26. In FIGS. 6A and 6B, the stent 12 and the
marker 27 have been cut longitudinally and laid flat. The stent 12
has a length L and a circumference C. In FIG. 6A, the marker 27 and
the stent 12 are shown disengaged from one another. In FIG. 6B
marker 27 and the stent 12 are shown interlocked. In both FIGS. 6A
and 6B, the stent is in the reduced diameter configuration.
Similarly, the stents depicted in FIGS. 7-15B are shown in the
reduced diameter orientation.
[0058] Referring to FIG. 6A, the stent 12 includes a plurality of
struts 86 (i.e., reinforcing members). At least some of the struts
86 have free terminal ends that define the proximal and distal ends
12a and 12b of the stent 12. Male interlock structures 82 (i.e.,
keys) are provided at the free terminal ends of the struts 86. As
shown in FIG. 6A, the male interlock structures 82 include
enlargements in the form of circular projections. The circular
projections include interlock portions 88 that project outwardly
from the struts 86 in a circumferential direction (i.e., in a
direction coinciding with the circumference C of the stent 12). The
interlock portions 88 include interlock surfaces 90 that face in an
axial direction. The phrase "face in an axial direction" will be
understood to mean that least a vector component of the surface 90
is perpendicular with respect to a longitudinal axis AA of the
stent 12. Thus, the surface 90 need not be completely perpendicular
relative to the longitudinal axis of the stent 12 to be construed
as facing in an axial direction. In other words, a surface aligned
at oblique angle relative to the longitudinal axis of the stent 12
shall also be construed as facing in an axial direction since such
surface has a vector component that is perpendicular relative to
the longitudinal axis of the stent.
[0059] As best shown schematically in FIG. 6C, the male interlock
structures 82 are preferably positioned within a region defined
between an inner diameter D1 and an outer diameter D2 of the stent
12. This is preferably true regardless of whether the stent 12 is
in the expanded diameter orientation or the reduced diameter
orientation. Preferably, at least portions of the interlock
surfaces 90 are located within 5 millimeters of the proximal end
12a of the stent 12. More preferably, at least portions of the
interlock surfaces 90 are located within 3 millimeters of the
proximal end 12a of the stent 12. Most preferably, at least
portions of the interlock surfaces 90 are located within 2
millimeters of the proximal end 12a of the stent 12.
[0060] Referring to FIG. 6A, the stent 12 includes a lumen
reinforcing structure including a plurality of struts 13 adapted to
define open cells 15 (best shown in FIG. 2B) when the stent 12 is
deployed. Preferably, the male interlock structures 82 are located
within 5 millimeter of the struts 13 that define the open cells 15.
More preferably, the male interlock structures 82 are located
within 4, 3 or 2 millimeters of the struts 13 that define the open
cells 15. Most preferably, the male interlock structures 82 are
located within 1 millimeter of the struts 13 that define the open
cells 15. Because the male interlock structures 82 are located
relatively close to the structure defining the open cells 15,
during deployment of the stent 12, the male interlock structures 82
will expand radially outwardly simultaneously with the radial
expansion of at least a portion of the cell defining structure.
When the stent 12 is expanded, the interlock structures 82 are
preferably maintained generally within a boundary defined by the
inner and outer diameters of the cell defining portion of the
stent, and preferably the interlock structures 82 are not biased or
angled radially outwardly relative to the cell defining
portion.
[0061] Still referring to FIGS. 6A and 6B, the marker 27 has an
axial distal edge 29 facing the proximal end 12a of stent 12.
Female interlock structures 84 (i.e., sockets, openings, keyways,
etc.) are defined by the marker 27 adjacent the edge 29. The female
interlock structures 84 are configured to have a complimentary
mating geometry with respect to the male interlock structures 82 of
the stent 12. For example, similar to the male interlock structures
82, the female interlock structures 84 are shown having generally
rounded or circular shapes. Each of the female interlock structures
84 includes interlock surfaces 92 that face in an axial
direction.
[0062] The geometry of the female interlock structures 84 is
selected to mate with the predetermined geometry of the stent
proximal end 12a such that the stent 12 and the marker 27 can be
axially coupled or interlocked when the stent 12 is compressed at
the mounting location 26. When the male and female interlock
structures 82 and 84 are interlocked, the interlock surfaces 90 and
92 oppose and circumferentially overlap one another (see FIG. 6B)
such that the stent is restricted from distal movement relative to
the marker 27.
[0063] With the specific embodiment shown, the stent 12 and collar
27 are rotary coupled such that the stent 12 and collar 27 are
restricted from relative rotary motion (i.e., about axis X-X) when
the stent 12 is in the collapsed state. The predetermined stent
geometry of the interlock structures 82 and the complementary
mating geometry of the collar 27 do not restrict relative radial
motion. Namely, as the self-expanding stent 12 expands radially,
the male interlock structures 82 are free to radially move out of
the female interlock structures 84. After such motion, the stent 12
is no longer coupled to the collar 27 and the stent 12 and collar
27 are free to move axially, radially or transversely to one
another.
[0064] With the embodiment thus described, the mating features of
the stent 12 and collar 27 prevent premature discharge of the stent
12 from a stent attachment location 26. As the outer sheath 16 is
retracted, the sheath distal end 16b exposes the distal end 12b of
the stent 12. At this point, the exposed distal end 12b of the
stent 12 is free for limited expansion restrained by the remainder
of the stent 12 being covered by the sheath 16 and by the
attachment of the stent proximal end 12a to the proximal marker
27.
[0065] Further retraction of the sheath 16, permits still further
expansion of the stent 12. As the sheath distal end 12b approaches
the stent proximal end 12a, the expansion of the stent material
tends to urge the stent 12 to squeeze out of the small portion of
the sheath 16 now covering the stent 12. However, this propensity
is overcome by the attachment of the stent proximal end 12a to the
collar 27 since any such ejection of the stent 12 would require
axial separation of the stent 12 and collar 27. Such movement is
prevented by the male interlock structures 82 and the female
interlock structures 84.
[0066] Therefore, as long any portion of the sheath 16 overlies the
male and female interlock structures 82 and 84, the proximal end
12a of the stent 12 cannot expand and cannot axially move away from
the collar 27. Accordingly, the stent 12 is not released from the
attachment location 26 until the physician has fully retracted the
sheath 16 with the sheath distal end 16b retracted proximal to the
proximal end of stent attachment location 26. The sheath distal end
16b is provided with a marker 16b' (shown in FIGS. 2A and 2B) to
permit visualization of the relative position of the sheath distal
end 12b and the markers 27, 28 of the stent attachment location
26.
[0067] With the structure and operation thus described, the
physician has greater control of the release of the stent 12. More
accurate stent positioning is attained. As long as even a small
portion of the sheath 16 is not fully retracted (e.g., at least 1
mm extends distally to the proximal end 12a of the stent 12) the
axial position of the stent 12 can be adjusted by advancing or
retracting the inner tubular member 14. Also, as long as a small
portion of the sheath 16 remains covered by the sheath 16 (e.g., at
least 1 mm), the stent 12 can be readily re-sheathed by moving the
sheath 16 in a distal direction.
[0068] In the embodiment of FIGS. 6A and 6B, the female and male
interlock structures 82 and 84 have complementary mating
geometries. It will be appreciated that in alternative embodiments,
the female and male interlock structures need not have
complementary/identical shapes. Instead, to provide an interlock,
it is only necessary for a portion of the male interlock to be
received in the female interlock such that mechanical interference
or overlap between the interlocks prevents the interlocks from
being axially separated. This can be accomplished without having
identical mating shapes.
[0069] As described above, the interlock structure 84 of the inner
tube 14 is provided on the proximal marker 27. It will be
appreciated that the interlock structure 84 need not be the same
element as the marker but could be a separate part. As a separate
part, the interlock structure could be integrally formed/connected
with the exterior of the inner tube 14, connected to the outer
surface of the inner tube by conventional techniques (e.g.,
adhesive, fasteners, fusion bonding, etc.), or be connected to the
outer surface of the inner tube 14 by one or more intermediate
members. Further, the embodiment of FIGS. 6A and 6B shows that the
interlock between the stent 12 and the tube 14 is provided at the
proximal end 12a of the stent 12b. It will be appreciated that for
certain embodiments, the interlock between the inner tube 14 and
the stent 12 can be provided at the distal end 12b of the stent 12
(e.g., for a distally retractable sheath). Moreover, while the
embodiment of FIGS. 6A and 6B shows interlock structures provided
at all of the proximal ends of the struts 86, the invention is not
so limited. For example, in some embodiments, only some of the
struts 86 may include interlock structures. While in certain
embodiments it may be desirable to use only one interlock structure
at the end of the stent 12, it is preferable to use at least two
separate/discrete interlock structures uniformly spaced about the
circumference of the stent. It is more preferable to use at least 4
separate/discrete interlock structures that are preferably
uniformly spaced about the circumference of the stent.
[0070] The collar 27 may be provided with indicia to indicate to a
physician the position of the collar 27 (and hence the stent 12)
when the combination is in a patient's vessel and is being
visualized under fluoroscopy. In the embodiment of FIGS. 6A and 6B,
the indicia is shown as cutouts 15 in the collar 27. FIG. 7 shows a
collar 27' having indicia in the form of proximal projections 15'
off of the proximal edge of the collar 27'. FIG. 8 shows a collar
27' having indicia in the form of triangular notches 15' defined at
the proximal edge of the collar 27'. In the embodiments shown, the
indicia 15, 15' and 15" are spaced apart circumferentially on their
respective collars 27, 27' and 27" so that the indicia are 180
degrees apart.
[0071] In the embodiment of FIGS. 6A and 6B, the pattern and shape
of the male interlock structures 82 and the female interlock
structures 84 are symmetrical about the stent axis X-X. As a
result, the stent 12 can be affixed to the collar 27 in any one of
a plurality of rotary alignments about axis X-X.
[0072] FIG. 9 illustrates an embodiment of a collar 127 and stent
112 where the symmetrical pattern is interrupted. In the example of
FIG. 9, a single unique key 117 is provided (which, in the example
shown, has a square geometry compared to the circular geometry of
remaining male interlock structures 182). Similarly, the collar 127
has a unique keyway 117a to mate with the unique key 117. As a
result, the stent 112 can only be affixed to the collar 127 in one
rotary alignment.
[0073] In all of the above embodiments, once the position of a
stent is fixed to a collar, a non-symmetrical stent feature (e.g.,
an opening for placement at a bifurcation in a vessel) can be
aligned with the indicia (or, if desired, a single indicia can be
provided on the collar). Therefore, a physician can easily
visualize the position of any non-symmetrical stent feature.
[0074] FIG. 10 illustrates an embodiment of a stent 212 and
radiopaque collar 227 having another interlock configuration. The
collar 227 has circumferential slots 228 for assisting in
adhesively bonding the collar 227 to the outer surface of the inner
tube 14. The stent 212 has proximal and distal ends 212a and 212b.
The stent also includes proximal end struts 286a having free ends
at which male interlock structures 282 are formed. The male
interlock structures 282 are formed by notches cut into the
proximal end struts 286a. The male interlock structures 282 include
axially facing interlock surfaces 290 that face in a distal
direction. Preferably, the surfaces 290 are located within 5
millimeters of the proximal end 212a of the stent 212, and within
1, 2, 3, 4 or 5 millimeters of a cell defining portion of the
stent.
[0075] The collar 227 includes female interlock structures 284 in
the form of sockets. The sockets are partially defined by
projections adapted to fit within the notches cut into the proximal
end struts 286a. The projections define axially facing interlock
surfaces 292 that face in a proximal direction. When the male and
female interlock structures 282 and 284 are interlocked, the
surfaces 290 and 292 oppose one another to prevent the male
interlock structures 282 from being axially withdrawn from the
female interlock structures 284.
[0076] FIG. 11 illustrates an embodiment of a stent 312 and
radiopaque collar 327 having another interlock configuration. The
collar 327 has circumferential slots 328 for assisting in
adhesively bonding the collar 327 to the outer surface of the inner
tube 14. The stent 312 has proximal and distal ends 312a and 312b.
The stent also includes proximal end struts 386a having free ends
at which male interlock structures 382 are formed. The male
interlock structures 382 are formed by enlarged heads (i.e.,
protuberances or keys) located at the ends of the end struts 386a.
The male interlock structures 382 include axially facing interlock
surfaces 390 that face in a distal direction. Preferably, the
surfaces 390 are located within 5 millimeters of the proximal end
312a of the stent 312, and within 1, 2, 3, 4 or 5 millimeters of a
cell defining region of the stent. The collar 327 includes female
interlock structures 384 in the form of sockets. The female
interlock structures 384 include axially facing interlock surfaces
392 that face in a proximal direction. When the male and female
interlock structures 382 and 384 are interlocked, the surfaces 390
and 392 oppose one another to prevent the male interlock structures
382 from being axially withdrawn from the female interlock
structures 384.
[0077] FIG. 12 illustrates an embodiment of a stent 412 including
female interlock structures 484. The female interlock structures
484 preferably include distally facing interlock surfaces 492
located within 5 mm of a proximal end 412a of the stent 412 and
within 1, 2, 3, 4 or 5 millimeters of a cell defining region of the
stent. The female interlock structures 484 are sized to receive
male interlock structures 482 in the form of rectangular posts.
Preferably, the posts are connected to the outer surface of the
inner tube 14 (e.g., integrally or otherwise). The posts define
proximally facing interlock surfaces 490. When the female and male
interlock structures 484 and 482 are coupled, the surfaces 490 and
492 engage each other to prevent distal movement of the stent 412
relative to the posts.
[0078] FIG. 13 illustrates an embodiment of a stent 512 including
male interlock structures 582 in the form of hooks. The male
interlock structures 582 preferably include distally facing
interlock surfaces 590 located within 5 mm of a proximal end 512a
of the stent 512 and within 1, 2, 3, 4 or 5 millimeters of a cell
defining region of the stent. The male interlock structures 582 are
sized to fit within female interlock structures 584 defined by a
collar 527. The female interlock structures 584 define proximally
facing interlock surfaces 592. When the female and male interlock
structures 584 and 582 are coupled, the surfaces 590 and 592 engage
each other to prevent distal movement of the stent 512 relative to
the collar 527.
[0079] FIGS. 14A and 14B illustrate an embodiment of a stent 612
including female interlock structures 684 in the form of
longitudinal slots between or within struts. The female interlock
structures 684 preferably include distally facing interlock
surfaces 692 (e.g., defined by the proximal ends of the slots)
located within 5 mm of a proximal end 612a of the stent 612 and
within 1, 2, 3, 4 or 5 millimeters of a cell defining region of the
stent. The female interlock structures 684 are sized to receive
male interlock structures 682 in the form of linear posts.
Preferably, the posts are connected to the outer surface of the
inner tube 14 (e.g., integrally or otherwise). The posts define
proximally facing interlock surfaces 690 (e.g., at the proximal
ends of the posts). When the female and male interlock structures
684 and 682 are coupled as shown in FIG. 14B, the surfaces 690 and
692 engage each other to prevent distal movement of the stent 612
relative to the posts.
[0080] FIGS. 15A and 15B illustrate an embodiment of a stent 712
including female interlock structures 784 in the form of circular
openings defined through enlarged strut ends of the stent 712. The
female interlock structures 784 preferably include distally facing
interlock surfaces 792 located within 5 mm of a proximal end 712a
of the stent 712 and within 1, 2, 3, 4 or 5 millimeters of a cell
defining region of the stent. The female interlock structures 784
are sized to receive male interlock structures 782 in the form of
cylindrical posts or pins. Preferably, the posts are connected to
the outer surface of the inner tube 14 (e.g., integrally or
otherwise). The posts define proximally facing interlock surfaces
790. When the female and male interlock structures 784 and 782 are
coupled as shown in FIG. 15B, the surfaces 790 and 792 engage each
other to prevent distal movement of the stent 712 relative to the
posts.
[0081] FIGS. 16A and 16B show a stent delivery system 10' that is
another embodiment of the present invention. The delivery system
10' includes an inner member 14' and an outer sheath 16'. The inner
member 14' includes a flexible distal tip 30' and a stent mounting
location 26'. Proximal and distal markers 27' and 28' are located
on opposite sides of the mounting location 26'. The proximal marker
27' includes interlock structures in the form of receivers 84' or
receptacles. The receivers 84' are adapted to receive and interlock
with interlock structures in the form of enlargements 82' provided
at the proximal end of self expanding stent 12'. The enlargements
82' are preferably within 1, 2, 3, 4 or 5 millimeters of cell
defining structures 83' of the stent 12'.
[0082] While the various embodiments of the present invention have
related to stents and stent delivery systems, the scope of the
present invention is not so limited. For example, while
particularly suited for stent delivery systems, it will be
appreciated that the various aspects of the present invention are
also applicable to systems for delivering other types of
self-expandable implants. By way of non-limiting example, other
types of self-expanding implants include anastomosis devices, blood
filters, grafts, vena cava filters, percutaneous valves, or other
devices. Also, while it is preferred for the interlocks of the
present invention to be within 5 millimeters of an end of their
corresponding implant to enhance deployment control, larger
spacings could be used for certain applications. Similarly, while
it is preferred for the interlocks to be within 5, 4, 3, 2 or 1
millimeters of cell defining regions of the stents, other spacings
could be used in certain alternative embodiments.
[0083] It has been shown how the objects of the invention have been
attained in a preferred manner. Modifications and equivalents of
the disclosed concepts are intended to be included within the scope
of the claims.
* * * * *