U.S. patent application number 11/742459 was filed with the patent office on 2007-11-15 for multiple component prosthetic heart valve assemblies and apparatus for delivering them.
Invention is credited to Donnell W. Gurskis, James Hong, Takashi Harry Ino, Mimi Nguyen-Fitterer.
Application Number | 20070265701 11/742459 |
Document ID | / |
Family ID | 42313327 |
Filed Date | 2007-11-15 |
United States Patent
Application |
20070265701 |
Kind Code |
A1 |
Gurskis; Donnell W. ; et
al. |
November 15, 2007 |
MULTIPLE COMPONENT PROSTHETIC HEART VALVE ASSEMBLIES AND APPARATUS
FOR DELIVERING THEM
Abstract
Multiple component heart valves and apparatus and methods for
implanting them are provided. The heart valve generally includes a
first annular prosthesis and a second valve prosthesis. The first
prosthesis includes an annular member compressible from a relaxed
condition to a contracted condition to facilitate delivery into a
biological annulus, the annular member being resiliently expandable
towards the relaxed condition. The first prosthesis also includes
guide rails extending therefrom. The second prosthesis includes an
annular frame, valve elements, and receptacles for receiving
respective guide rails therethrough when the second prosthesis is
directed towards the first prosthesis. In addition, a valve holder
may releasably carry the valve prosthesis that includes channels
for receiving respective guide rails therethrough when the guide
rails are received through the valve prosthesis. A delivery tool is
also provided that includes an actuator for selectively compressing
the annular member into the contracted condition.
Inventors: |
Gurskis; Donnell W.;
(Belmont, CA) ; Nguyen-Fitterer; Mimi; (Redwood
City, CA) ; Ino; Takashi Harry; (San Jose, CA)
; Hong; James; (Palo Alto, CA) |
Correspondence
Address: |
Vista IP Law Group LLP
2040 MAIN STREET, 9TH FLOOR
IRVINE
CA
92614
US
|
Family ID: |
42313327 |
Appl. No.: |
11/742459 |
Filed: |
April 30, 2007 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
60746038 |
Apr 29, 2006 |
|
|
|
60914742 |
Apr 29, 2007 |
|
|
|
Current U.S.
Class: |
623/2.1 ;
606/108; 623/2.4 |
Current CPC
Class: |
A61F 2/2439 20130101;
A61F 2220/005 20130101; A61F 2250/0063 20130101; A61F 2/243
20130101; A61F 2/2409 20130101; A61F 2220/0058 20130101; A61B
17/0469 20130101; A61F 2/2427 20130101; A61B 2017/00243 20130101;
A61F 2/2418 20130101 |
Class at
Publication: |
623/002.11 ;
606/108 |
International
Class: |
A61F 2/24 20060101
A61F002/24 |
Claims
1. A system for replacing a native or prosthetic heart valve within
a patient's heart, comprising: a first prosthesis comprising an
annular member implantable within the biological annulus and a
plurality of elongate guide rails; a second valve prosthesis
comprising an annular frame, at least one valve element, and a
plurality of receptacles for slidably receiving respective guide
rails therethrough when the second prosthesis is directed towards
the first prosthesis; and a valve holder comprising proximal and
distal ends, the second prosthesis being releasably carried by the
distal end, the valve holder comprising a plurality of channels for
receiving respective guide rails therethrough when the guide rails
are received through the receptacles of the second prosthesis.
2. The system of claim 1, wherein the annular member is
compressible radially inwardly from a relaxed condition to a
contracted condition to facilitate delivery into a biological
annulus, the annular member being resiliently expandable towards
the relaxed condition.
3. The system of claim 2, further comprising a delivery tool for
introducing the first prosthesis into a biological annulus, the
delivery tool comprising a plurality of movable arms disposed
around a central hub for selectively compressing the annular member
between the arms and the hub to place the annular member in the
contracted condition.
4. The system of claim 1, wherein the first prosthesis comprises a
plurality of guide shields extending upwardly therefrom for guiding
the second prosthesis towards the first prosthesis.
5. The system of claim 4, wherein the guide rails are releasably
constrained by the guide shields.
6. The system of claim 1, wherein the second prosthesis is
releasably attached to a head of the valve holder by one or more
sutures.
7. The system of claim 1, wherein the valve holder comprises a
plurality of tubular members defining the channels for receiving
the guide rails.
8. The system of claim 7, wherein the tubular members are rotatable
for severing the guide rails to separate the guide rails from the
first prosthesis.
9. The system of claim 7, wherein the tubular members are coupled
to a hub on a shaft of the valve holder, the hub being rotatable
relative to the shaft for severing the guide rails to separate the
guide rails from the first prosthesis.
10. The system of claim 1, wherein the valve holder comprises an
actuator that engages the guide rails when the guide rails are
received in the channels, the actuator being movable proximally on
a shaft of the valve holder for severing the guide rails to
separate the guide rails from the first prosthesis.
11. A prosthesis for receiving a valve prosthesis to replace a
preexisting natural or prosthetic heart valve within a biological
annulus, comprising: an annular member implantable within the
biological annulus; a sewing cuff extending outwardly from the
annular member; a plurality of elongate leaders comprising a first
end coupled to one of the annular member and the sewing cuff for
guiding a valve prosthesis towards at least one of the sewing cuff
and the annular member; and connectors on the leaders disposed a
predetermined distance from the first end for securing a valve
prosthesis relative to the prosthesis.
12. The prosthesis of claim 11, wherein the sewing cuff is
configured for receiving one or more connectors for attaching the
prosthesis to the biological annulus.
13. The prosthesis of claim 11, wherein the annular member is at
least partially expandable from a contracted condition to an
enlarged condition.
14. The prosthesis of claim 11, wherein the annular member
comprises a central longitudinal axis, the annular member being
directable from an enlarged condition having a first cross-section
to a contracted condition having a second cross-section smaller
than the first condition when the leaders are tensioned inwardly
towards the central axis.
15. The prosthesis of claim 14, wherein the annular member changes
shape between the enlarged and contracted conditions when the
leaders are tensioned inwardly.
16. The prosthesis of claim 14, wherein the annular member has a
generally circular cross-section in the enlarged condition and a
multiple lobular cross-section in the contracted condition.
17. The prosthesis of claim 11, wherein the first ends of the
leaders are fixed to the sewing cuff adjacent the annular member,
the leaders being spaced apart about a circumference of the sewing
cuff.
18. The prosthesis of claim 11, wherein the connectors comprise
ratcheting elements comprising tapered proximal edges and
substantially blunt distal edges.
19. The prosthesis of claim 11, wherein the connectors comprise a
tapered arrow shape allowing unidirectional penetration through
valve prosthesis.
20. The prosthesis of claim 11, wherein the connectors comprise
knots.
21. A heart valve assembly implantable within a biological annulus,
comprising: a first prosthesis comprising an annular member
implantable within a biological annulus, and a sewing cuff
extending outwardly from the annular member; a second valve
prosthesis comprising an annular frame and at least one valve
element; a plurality of elongate leaders extending from the first
prosthesis for guiding the second prosthesis towards the first
prosthesis; and connectors on the leaders for securing the second
prosthesis relative to the first prosthesis.
22. The heart valve assembly of claim 21, wherein the second
prosthesis comprises one of a mechanical valve and a bioprosthetic
valve.
23. The heart valve assembly of claim 21, wherein the second
prosthesis comprises a plurality of introducers for receiving
respective leaders therethrough.
24. The heart valve assembly of claim 23, wherein the introducers
comprise tubular members removably secured to respective portions
of the second prosthesis.
25. The heart valve assembly of claim 23, wherein the introducers
comprise pockets on the second prosthesis.
26. The heart valve assembly of claim 21, wherein the connectors
comprise ratcheting elements comprising tapered proximal edges and
substantially blunt distal edges.
27. The heart valve assembly of claim 21, wherein the connectors
comprise a tapered arrow shape allowing unidirectional penetration
through the valve prosthesis.
28. The heart valve assembly of claim 21, wherein the connectors
comprise knots.
29. The heart valve assembly of claim 21, wherein the annular
member is compressible to a contracted condition to facilitate
delivery into a biological annulus and resiliently expandable to an
enlarged condition released from the contracted condition.
30. The heart valve assembly of claim 21, wherein the leaders
comprise weakened regions above the connectors, the weakened
regions configured to break when the leaders are subjected to a
predetermined tension.
31. A tool for implanting a prosthesis into a biological annulus,
comprising: an elongate shaft comprising a proximal end and a
distal end; a plurality of supports on the distal end; a plurality
of movable arms on the distal end adjacent the supports; and an
actuator on the proximal end for moving the arms towards and away
from the supports for securing and releasing an annular prosthesis
between the supports and the arms, the prosthesis being folded into
a contracted condition when secured between the supports and the
arms.
32. The tool of claim 31, wherein the supports are disposed about a
longitudinal axis defined by the shaft, and the arms are offset
radially about the longitudinal axis between adjacent supports.
33. The tool of claim 31, wherein the plurality of supports
comprise three supports and the plurality of arms comprises three
arms, thereby deforming the prosthesis into a generally shamrock
shape when the prosthesis is secured between the supports and the
arms.
34. A system for delivering a heart valve prosthesis, comprising: a
valve prosthesis comprising a frame carrying one or more leaflets;
a valve holder comprising proximal and distal ends, a head on the
distal end; and one or more fasteners for removably securing the
valve prosthesis to the head.
35. The system of claim 34, wherein the one or more fasteners
comprise sutures.
36. The system of claim 34, the valve holder comprising a plurality
of channels aligned with receptacles on the valve prosthesis for
receiving guide rails from a gasket member therethrough.
37. The system of claim 36, further comprising an actuator on the
valve holder for severing the guide rails received in the
channels.
38. The system of claim 36, wherein the valve holder comprises a
plurality of tubular members defining the channels.
39. The system of claim 38, wherein the tubular members are
rotatable for severing the respective guide rails received
therein.
40. The system of claim 37, wherein the actuator comprises a
housing including features for securing free ends of the guide
rails therein, the housing being movable proximally relative to the
head for pulling the guide rails to cause the guide rails to break.
Description
RELATED APPLICATION DATA
[0001] This application claims benefit of co-pending provisional
application Ser. Nos. 60/746,038, filed Apr. 29, 2006, and
60/914,742, filed Apr. 29, 2007, the entire disclosures of which
are expressly incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The present invention relates generally to heart valves that
may be implanted within a patient, and, more particularly, to
multiple component heart valve assemblies that may be assembled
together, and to apparatus and methods for using them.
BACKGROUND
[0003] Prosthetic heart valves can replace defective human valves
in patients. For example, one piece valves have been suggested that
include sewing rings or suture cuffs that are attached to and
extend around the outer circumference of a prosthetic valve. In
addition, multiple component valves have also been suggested that
include a sewing ring that is separate from a valve component. The
sewing rings of either type of prosthetic valve can be tedious and
time consuming to secure within a target site, i.e., within an
annulus of a heart where a natural heart valve has been
removed.
[0004] For example, to implant a sewing ring within an annulus of a
heart, between twelve and twenty sutures may be secured initially
to tissue surrounding the annulus. The sewing ring and/or the
entire prosthetic valve may then be advanced or "parachuted" down
the sutures into the annulus. Knots may then be tied with the
sutures to secure the sewing ring within the annulus, whereupon the
sutures may be cut. Consequently, this procedure can be very
complicated, requiring management and manipulation of many sutures.
The complexity of the procedure also provides a greater opportunity
for mistakes and requires a patient to be on cardiopulmonary bypass
for a lengthy period of time.
[0005] Because the annulus of the heart may not match the circular
cross-section of the sewing ring and/or prosthetic valve, the
prosthetic valve may not fit optimally within the annulus. As a
result, natural blood hemodynamics through and around the valve may
be impaired, resulting in clotting, possible emboli production, and
eventual calcification of the valve structure.
[0006] To address this concern, flexible sewing rings have been
suggested for use with multiple component valves. The sewing ring
may be implanted within the annulus, e.g., using the procedure
described above, i.e., parachuted down an arrangement of sutures.
The sewing ring may conform at least partially to the anatomy of
the annulus. Alternatively, instead of using sutures, it has also
been suggested to drive staples through the sewing ring into the
surrounding tissue to secure the sewing ring.
[0007] When a mechanical or prosthetic valve is then attached to
the sewing ring, however, the valve and sewing ring may not mate
together effectively, e.g., if the shape of the sewing ring has
been distorted to conform to the annulus, which may also impair
natural blood hemodynamics, create leaks, and/or otherwise impair
performance of the prosthetic valve.
[0008] In addition, less invasive or minimally invasive procedures
are often desirable, because they may reduce stress on the
patient's body and/or accelerate recovery after a procedure. Such
procedures may involve creating smaller access sites and/or even
using ports to access a procedure site. During valve replacement,
in order to introduce a prosthetic heart valve and/or sewing ring
into a patient's heart, the heart must be accessed, e.g., by
sternotomy or thoracotomy. The resulting opening must be
sufficiently large to permit passage of the prosthetic heart valve
and still allow the physician to access and/or observe the site of
implantation. Thus, conventional procedures for implanting
prosthetic heart valves may not be compatible with less invasive or
minimally invasive procedures.
SUMMARY OF THE INVENTION
[0009] The present invention is directed to prosthetic heart valves
that may be implanted within a patient, and, more particularly, to
multiple component heart valve assemblies that may be assembled
together, and to tools, apparatus, systems, and methods for making
and implanting them.
[0010] In accordance with one embodiment, a prosthesis is provided
for receiving a valve prosthesis to replace a natural or prosthetic
heart valve within a biological annulus. The prosthesis may include
an annular member implantable within the biological annulus for
contacting tissue surrounding the biological annulus, a sewing cuff
extending from the annular member, and a plurality of elongate
guide rails or other leaders extending from one of the annular
member and the sewing cuff for guiding a valve prosthesis towards
the prosthesis. Optionally, the annular member may be resiliently
compressible, expandable, and/or otherwise biased, and/or may
include a collar extending upwardly therefrom, a skirt, one or more
guide shields, and/or other components.
[0011] In accordance with another embodiment, a prosthesis is
provided for receiving a valve prosthesis to replace a natural or
prosthetic heart valve within a biological annulus. The prosthesis
may include an annular member that is compressible radially
inwardly from a relaxed or expanded condition to a contracted
condition to facilitate delivery into a biological annulus. When
the annular member is released from the contracted condition, the
annular member may resiliently expand towards the expanded
condition, e.g., to dilate tissue surrounding the biological
annulus. Optionally, the prosthesis may include a sewing cuff
extending from the annular member, a collar extending upwardly
therefrom, a skirt, a plurality of elongate guide rails or other
leaders extending from the prosthesis for guiding a valve
prosthesis member towards the prosthesis, and/or other
components.
[0012] In accordance with yet another embodiment, a prosthesis is
provided for receiving a valve prosthesis to replace a natural or
prosthetic heart valve within a biological annulus. The prosthesis
may include an annular member, and a plurality of guide rails or
other leaders extending from the annular member. Each of the
leaders may include a proximal end, a distal end secured to the
annular member, and one or more ratchets, clasps, locking tabs, or
other retention elements or connectors, e.g., configured to allow a
valve member to be directed distally but not proximally over the
connectors. In an exemplary embodiment, each of the connectors may
include a tapered proximal surface and a blunt distal surface. The
connectors may be spaced a predetermined distance from the annular
member to secure the valve member against or immediately adjacent
the annular member. Optionally, the annular member may be
compressible radially inwardly from a relaxed or expanded condition
to a contracted condition to facilitate delivery into a biological
annulus, resiliently expandable towards the expanded condition,
and/or otherwise biased.
[0013] In accordance with still another embodiment, a heart valve
assembly is provided that includes a first annular prosthesis
implantable within a biological annulus, a second valve prosthesis,
and a plurality of elongate guide rails or other leaders extending
from the first prosthesis for guiding the second prosthesis into
engagement with the first prosthesis. In exemplary embodiments, the
second prosthesis may be a mechanical valve or a bioprosthetic
valve, e.g., including multiple tissue leaflets carried by a
frame.
[0014] Optionally, the second prosthesis may include a plurality of
receptacles or other features for receiving respective leaders. For
example, the features may be ports or other receivers fixed to a
frame or wall of the second prosthesis, a plurality of tubular
members that may be removable from a frame, fabric covering, or
other portion of the second prosthesis, and the like.
[0015] In one embodiment, one or more connectors may be provided on
at least one of the first and second prostheses for securing the
second prosthesis to the first prosthesis. For example, the one or
more connectors may include one or more cooperating clips, detents,
and the like that self-engage one another when the second
prosthesis is directed towards the first prosthesis. In addition,
or alternatively, the leaders may include one or more ratchets,
clasps, locking tabs, or other retention elements or connectors for
securing the second prosthesis against or immediately adjacent the
first prosthesis.
[0016] In addition or alternatively, the first prosthesis may
include an annular member, a sewing cuff extending radially from
the annular member, and/or a skirt to enhance sealing between the
first prosthesis and surrounding tissue. In one embodiment, the
first prosthesis may also include a collar extending upwardly from
the annular member for receiving the valve member. The sewing cuff
and/or collar may be formed from resiliently flexible material,
e.g., silicone or polyester film, covered with a fabric
covering.
[0017] In accordance with yet another embodiment, a prosthetic
heart valve system is provided that includes a first annular
prosthesis, a second valve prosthesis, and one or more delivery
tools for introducing the first and/or second prostheses. The first
prosthesis may include an annular member implantable within a
biological annulus for contacting tissue surrounding the biological
annulus, a sewing cuff extending radially outwardly from the
annular member, and a plurality of elongate guide rails or other
leaders extending from one of the annular member and the sewing
cuff for guiding the valve prosthesis towards the sewing cuff.
[0018] The one or more delivery tools may include an elongate
member including a proximal end, a distal end sized for
introduction into a biological annulus, and an actuator for
directing the first prosthesis between an expanded or relaxed
condition and a contracted condition that facilitates introduction
into a biological annulus. In one embodiment, the tool may include
a groove or lumen extending between the proximal and distal ends
thereof for receiving portions of the leaders therethrough. The
actuator may include a handle at the proximal end and one or more
mechanisms for locking, tightening, and/or releasing the leaders
received in the groove or lumen, e.g., to facilitate tightening
and/or loosening the leaders. Thus, the first prosthesis may be
releasably engaged with the distal end of the delivery tool when
the leaders are secured to the delivery tool. For example, the
first prosthesis may be compressible from an expanded or relaxed
condition to a contracted condition when the leaders are tensioned,
thereby drawing portions of the first prosthesis inwardly towards
the distal end of the delivery tool.
[0019] In another embodiment, the tool may include a central hub or
support and a plurality of movable arms for capturing the first
prosthesis between the support and arms. The actuator may direct
the arms inwardly and outwardly for directing the first prosthesis
to the contracted condition and releasing the first prosthesis from
the tool. In an exemplary embodiment, in the contracted condition,
the first prosthesis may assume a clover or other multiple lobular
shape, while, in the expanded condition, the first prosthesis may
have a substantially circular shape. The first prosthesis may be
resiliently compressible such that, when the first prosthesis is
released, the first prosthesis may resiliently expand towards the
expanded condition.
[0020] In accordance with still another embodiment, a prosthetic
heart valve system is provided that includes a first annular
prosthesis and a delivery tool. The first prosthesis may be
resiliently compressible from a relaxed or expanded condition to a
contracted condition. The delivery tool may include one or more
constraints for maintaining the first prosthesis in the contracted
condition. For example, the delivery tool may include a plurality
of movable arms surrounding a central hub or set of supports, the
arms being movable towards and away from the hub for capturing
and/or compressing the first prosthesis between the arms and the
hub. The first prosthesis may be resiliently compressible such
that, when released from the one or more constraints, the first
prosthesis may resiliently expand towards the expanded
condition.
[0021] In accordance with yet another embodiment, a method is
provided for implanting a prosthetic heart valve assembly to
replace a natural or prosthetic heart valve within a biological
annulus below a sinus cavity. A first annular prosthesis may be
inserted into the biological annulus while in a contracted
condition. In one embodiment, the first prosthesis may include a
plurality of guide rails or other leaders extending from the
prosthesis. At least a first portion of the first prosthesis may be
deployed in the annulus so that the first prosthesis expands to an
enlarged state therein, e.g., to at least partially dilate tissue
surrounding the biological annulus. In addition or alternatively,
the first prosthesis may include a flexible sewing cuff and/or
skirt extending around the first prosthesis, which may be disposed
supra-annularly and/or sub-annularly when the first portion is
deployed in the biological annulus. One or more connectors, e.g.,
sutures, clips, and the like, may be directed through the first
prosthesis, e.g., through the sewing cuff, and adjacent tissue, to
secure the first prosthesis relative to the annulus.
[0022] A second valve prosthesis, e.g., a mechanical or
bioprosthetic valve, may be directed into the annulus adjacent the
first prosthesis. For example, the valve prosthesis may be advanced
along guide rails or other leaders extending from the first
prosthesis until the second prosthesis engages or otherwise
contacts the implanted first prosthesis. In one embodiment, the
valve prosthesis may be secured to the first prosthesis using one
or more connectors, e.g., one or more sutures, clips detents,
and/or other cooperating connectors, e.g., on the first prosthesis
and a frame of the valve prosthesis. In addition or alternatively,
the second prosthesis may be secured to the first prosthesis by
ratcheting, locking, or other retention elements or connectors on
the leaders.
[0023] In accordance with yet another embodiment, a method is
provided for implanting a prosthetic heart valve assembly to
replace a natural or prosthetic heart valve within a biological
annulus below a sinus cavity. A gasket member and delivery tool may
be provided with a plurality of elongate guide rails or other
leaders extending from the gasket member into a distal end of the
delivery tool. The leaders may be secured relative to the delivery
tool, e.g., by a locking mechanism. A tightening mechanism on the
delivery tool may be actuated to tension the leaders to compress
the gasket member to a contracted condition. Alternatively, the
delivery tool and gasket member may be initially provided with the
leaders already tensioned.
[0024] The distal end of the delivery tool may be introduced into
the sinus cavity, thereby carrying the gasket member in the
contracted state at least partially into the biological annulus.
The gasket member may be at least partially released from the
delivery tool, e.g., to at least partially dilate tissue
surrounding the biological annulus. For example, the locking
mechanism on the delivery tool may be released, unlocked, or
otherwise actuated to release the gasket member, allowing the
gasket member to expand resiliently towards an enlarged condition.
The gasket member may be attached to the biological annulus, e.g.,
using one or more fasteners, such as sutures, clips, and the
like.
[0025] A valve member may then be introduced into the sinus cavity
and secured to the first prosthesis. Optionally, the valve member
may be carried by the same delivery tool used to introduce the
gasket member or by a separate tool. The valve member may be
secured to the gasket member by one or more connectors, e.g.,
sutures, clips, detents, ratcheting or other retention elements,
and the like. In one embodiment, the valve member may be introduced
into the sinus cavity along the leaders and/or may be secured to
the gasket member by one or more connectors on the leaders.
[0026] In accordance with still another embodiment, a valve holder
device may be provided for delivering a valve prosthesis into a
biological annulus for connection to an annular prosthesis
previously introduced into the biological annulus and including one
or more guide rails or other leaders extending therefrom. For
example, the valve holder device may include one or more elements,
e.g., a head, for releasably carrying the valve prosthesis on a
distal end of the valve holder device. In addition, the valve
holder device may include one or more channels or other receivers
for receiving respective leaders, the receivers slidably receiving
the leaders while the valve holder device and valve prosthesis are
directed towards the annular prosthesis. Optionally, the valve
holder device may include one or actuators that may be manipulated
to sever the leaders after the valve prosthesis is secured relative
to the annular prosthesis.
[0027] Other aspects and features of the present invention will
become apparent from consideration of the following description
taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The drawings illustrate exemplary embodiments of the
invention, in which:
[0029] FIG. 1 is a perspective view of a two piece heart valve
assembly including a gasket member having elongate leaders
extending therefrom and a valve member.
[0030] FIG. 2 is a perspective view of an apparatus for delivering
the gasket member of FIG. 1 into a biological annulus that includes
a delivery tool for receiving the elongate leaders from the gasket
member.
[0031] FIG. 3A is a perspective view of the apparatus of FIG. 2,
showing the gasket member in a relaxed condition, when the leaders
are free from external forces.
[0032] FIG. 3B is a perspective view of the apparatus of FIGS. 2
and 3A, showing the gasket member in a contracted condition, when
tension is applied to pull the leaders further into the delivery
tool.
[0033] FIG. 4 is a perspective view of another embodiment of a
heart valve assembly, including a gasket member having elongate
leaders extending therefrom that include retention elements, and a
valve member.
[0034] FIGS. 5A-5C are cross-sectional views of a biological
annulus, showing a method for implanting the heart valve assembly
of FIG. 4.
[0035] FIG. 6 is a cross-sectional view of a biological annulus
showing an alternate embodiment of a valve member that may be
provided for a heart valve assembly implanted within the biological
annulus.
[0036] FIG. 7 is a perspective view of another alternate embodiment
of a valve member.
[0037] FIGS. 8A and 8B are perspective and top views, respectively,
of another embodiment of a gasket member including a plurality of
guide rails and guide shields.
[0038] FIG. 8C is a perspective view of an alternative embodiment
of a gasket member, including a collar extending upwardly for
receiving a valve member therein.
[0039] FIGS. 9A-9C are side, perspective, and end views,
respectively, of a tool for delivering the gasket member of FIGS.
8A and 8B.
[0040] FIGS. 10A and 10B are end and side views, respectively, of a
distal end of the tool of FIGS. 9A-9C, showing the gasket of FIGS.
8A and 8B secured thereto in a folded or contracted condition.
[0041] FIGS. 11A-11E show the gasket member of FIGS. 10A and 10B
being delivered into a biological annulus (FIG. 11B) in a
contracted condition (FIGS. 11A, 11C, 11D), aligned with
commissures of the annulus (FIGS. 11B, 11C), and released from the
tool (FIG. 11E).
[0042] FIG. 12 is an end view of an alternate contracted
configuration for the gasket member of FIGS. 8A and 8B, e.g.,
having a folded shape.
[0043] FIG. 13A is a perspective detail of a biological annulus
including the gasket member of FIGS. 8A and 8B delivered therein,
showing a guide shield of the gasket member.
[0044] FIG. 13B is a perspective detail of the biological annulus
of FIG. 13A, showing tools being used to deliver a fastener through
the gasket member into surrounding tissue.
[0045] FIGS. 14A-14C are details of the biological annulus of FIGS.
13A and 13B, showing the gasket member being secured to the
annulus.
[0046] FIGS. 15A and 15B are side and end views, respectively, of a
valve holder tool for delivering a valve prosthesis into a
biological annulus.
[0047] FIG. 15C is a longitudinal cross-section of the valve holder
tool of FIGS. 15A and 15B, taken along line 15C-15C.
[0048] FIG. 15D is a perspective view of a distal end of the valve
holder tool of FIGS. 15A-15C.
[0049] FIGS. 16A and 16B are perspective views of the valve holder
tool of FIGS. 15A-15D, showing an actuator on the valve holder in
distal and proximal positions, respectively.
[0050] FIG. 17A is a side view of the valve holder tool of FIGS.
15A-15D carrying a valve prosthesis.
[0051] FIG. 17B is a detail of a distal end of the valve holder
tool of FIG. 17A, showing a plurality of sutures securing the valve
prosthesis to the valve holder tool.
[0052] FIG. 17C is a detail of the distal end of the valve holder
tool of FIGS. 17A and 17B, showing passages for receiving
respective guide rails of a gasket member, such as that shown in
FIGS. 8A and 8B.
[0053] FIGS. 18A and 18B show the valve holder tool of FIG. 17A
being used to deliver the valve prosthesis into a biological
annulus along guide rails of a gasket member already delivered into
the annulus.
[0054] FIG. 18C is a detail showing the passages on the valve
holder tool of FIG. 17C with guide rails from a gasket member
extending through the passages.
[0055] FIG. 19A is a detail showing a method for removing guide
shields from a gasket member after a valve prosthesis has been
engaged with the gasket member.
[0056] FIG. 19B is a detail showing a method for removing a valve
prosthesis from the valve holder tool of FIGS. 17A and 17B by
cutting the sutures securing the valve prosthesis to the valve
holder tool.
[0057] FIGS. 19C and 19D show a distal end of the valve holder tool
of FIG. 19B being withdrawn after releasing the valve prosthesis
from the valve holder tool.
[0058] FIGS. 20A and 20B are details of a frame of a valve
prosthesis that includes a receptacle including a cantilever
spring, showing a track and locking elements being formed
therein.
[0059] FIGS. 20C and 20D are perspective and side details,
respectively, of the receptacle of FIGS. 20A and 20B receiving a
guide rail therethrough, the locking elements on the cantilever
spring causing the cantilever spring to defect outwardly to
accommodate locking tabs on the guide rail passing through the
receptacle.
[0060] FIG. 20E is a side detail of the frame of FIGS. 20A-20D with
the locking tabs of a guide rails engaged with the locking elements
of the receptacle and a top portion of the guide rails severed and
removed.
[0061] FIGS. 21A-21D are perspective views of a biological annulus
with a valve assembly including a gasket member and a valve
prosthesis (with leaflets omitted for clarity) implanted
therein.
[0062] FIGS. 22A and 22B are side views of another embodiment of a
valve holder tool for delivering a valve prosthesis into a
biological annulus.
[0063] FIGS. 23A and 23B are details showing a free end of a guide
rail being received within an actuator of the valve holder tool of
FIGS. 22A and 22B.
[0064] FIGS. 24A and 24B are front and back views, respectively, of
a receptacle that may be attached to a valve prosthesis.
[0065] FIGS. 25A and 25B are perspective views of a frame for a
valve prosthesis including the receptacle of FIGS. 24A and 24B
attached thereto.
[0066] FIG. 26 is a detail showing a guide rail being received
within the receptacle of FIGS. 25A and 25B.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0067] Turning to the drawings, FIGS. 1 and 2 show an exemplary
embodiment of a heart valve assembly 10 that generally includes a
gasket member 12 and a valve member 14. The gasket member 12 is an
annular shaped body generally defining a plane 16 and a central
longitudinal axis 17 extending substantially perpendicular to the
plane 16. As shown, the gasket member 12 includes an annular ring
18, a sewing cuff 20, and a plurality of elongate leaders, guide
rails, or other elements 50 extending from the sewing cuff 20 or
other portion of the gasket member 12, as described further below.
Optionally, the gasket member 12 may also include a flexible skirt
and/or baleen elements (not shown), e.g., surrounding the annular
ring 18, a collar, and/or a plurality of guide shields (also not
shown), similar to other embodiments described herein. A fabric
covering 21 may be provided on one or more components of the gasket
member 12, e.g., over the annular ring 18 and over a core of the
sewing cuff 20, as described further below.
[0068] In one embodiment, the annular ring 18 may have a generally
circular shape. Alternatively, the annular ring 18 may have a
multi-lobular shape about the circumference, e.g., including three
lobes separated by scallops or cusps (not shown) depending upon the
anatomy within which the annular ring 18 is to be introduced. The
annular ring 18 may be formed from an elastic or superelastic
material, for example, metal, such as Nitinol, stainless steel, and
the like, a polymer, or a composite material. Such material may
facilitate compression and/or expansion of the annular ring 18, as
described further below.
[0069] In an exemplary embodiment, the annular ring 18 may be cut
from a flat sheet of base material having a desired thickness for
the annular ring 18, for example, by laser cutting, mechanical
cutting, and the like. Thus, the annular ring 18 may be initially
formed as a long band of material, having a width corresponding to
the desired width of the annular ring 18 and a length corresponding
to the desired circumference of the annular ring 18. The band may
be wrapped around a mandrel or otherwise restrained in a generally
cylindrical shape with the ends adjacent to one another, and the
band may be heat treated or otherwise processed to program the
generally cylindrical shape into the material to create the annular
ring 18. The generally cylindrical shape may include the ends
overlapping one another, spaced apart from one another to provide
an open "C" shape, or attached to one another. In another exemplary
embodiment, the annular ring 18 may be manufactured from a solid
rod of material, e.g. Nitinol, stainless steel, a polymer, or
composite material, e.g., by machining, electrical discharge
machining ("EDM"), laser cutting, or other processes.
[0070] Optionally, the annular ring 18 may be heat treated to
program a shape memory into the band material, e.g., when the
material is in an austentic state. For example, the programmed
shape may be an enlarged or relaxed condition, e.g., having a
substantially circular shape. The composition of the material may
be such that the annular ring 18 transforms to a substantially
martensitic state substantially below body temperature, e.g., at or
below ambient temperatures (e.g., 20.degree. C. or less). Thus, in
the martensitic state (before delivery), the annular ring 18 may be
relatively soft such that the annular ring 18 may be plastically
compressed or otherwise deformed, e.g., into a contracted condition
to facilitate delivery, as described below. A transition
temperature of the material may be set such that the annular ring
18 transforms substantially back to an austenitic state close to or
at about body temperature (e.g., at 37.degree. C. or more). Thus,
once the annular ring 18 is exposed within a patient's body, the
annular ring 18 may automatically become biased towards the
enlarged condition due the shape memory of the austenitic
state.
[0071] Alternatively, the material may be programmed to assume an
austenitic state at both ambient and body temperatures, but within
the elastic or superelastic range of the material. Thus, the
annular ring 18 may be elastically compressed into the contracted
condition, but may resiliently expand towards the enlarged
condition when released from any constraints maintaining the
annular ring 18 in the contracted condition.
[0072] The annular ring 18 may be at least partially covered with
fabric, e.g., for tissue ingrowth, by wrapping fabric around the
annular ring 18, while accommodating expansion and contraction of
the annular ring 18. For example, at least near the ends of the
band forming the annular ring 18, the fabric may not be secured to
the annular ring 18, allowing the ends to slide circumferentially
relative to the fabric. Optionally, sutures and the like (not
shown) may be used to secure the fabric to the annular ring 18 at
locations removed from the ends, e.g., at an intermediate location
about the circumference of the annular ring 18. Alternatively, the
entire annular ring 18 may be free to slide within the fabric
wrapped around the annular ring 18.
[0073] With continued reference to FIGS. 1 and 2, the sewing cuff
20 may be attached to or otherwise extend around the annular ring
18. The sewing cuff 20 may simply be one or more layers of fabric
or other material covering at least a portion of the annular ring
18. For example, a layer of fabric 21 may cover all of the annular
ring 18 (other than any connectors and/or bearing surfaces, if any)
and/or may include a section of material extending radially
outwardly from the annular ring 18 to at least partially define the
sewing cuff 20.
[0074] Optionally, the sewing cuff 20 may include flexible core
material (not shown) that may be attached to or otherwise extend
around the annular ring 18. For example, the core may be secured
around the annular ring 18 by an interference fit, bonding, fusing
a portion of the core to the annular ring 18, e.g., along an upper
edge thereof, and the like. The core may be substantially covered
with fabric, similar to the annular ring 18.
[0075] In an exemplary embodiment, the core may include a lattice
(not shown) extending around a circumference of the core, e.g.,
including at least two spaced apart circumferential elements and a
plurality of ribs or transverse elements extending between the
circumferential elements, thereby defining openings through the
lattice. The openings may be completely open, i.e., free from any
material. Alternatively, the openings may be recesses including a
relatively thin wall of core material, i.e., that is substantially
thinner than the circumferential elements and/or ribs. In other
embodiments, the core may include a base or web and a plurality of
fins or ribs extending from the web to provide a flexible
structure, e.g., which may facilitate sealing between the sewing
cuff 20 and valve member 14.
[0076] Exemplary materials for the core include silicone or other
elastomeric materials, foam, fabric, felt, polymers, and the like.
In addition or alternatively, the core may include swellable
material, e.g., foam or sponge materials that may expand when
exposed to fluid, such as blood. The materials may be molded or
otherwise formed into the core, e.g., using known molding,
extrusion, cutting, or other manufacturing procedures. For example,
the core may be injection molded or otherwise formed in its annular
shape.
[0077] Alternatively, the core may be molded or otherwise formed as
a flat sheet, and rolled into the annular shape. In this
alternative, the ends of the sheet may be attached to one another,
e.g., using sutures, adhesives, ultrasonic welding, and the like.
Optionally, to provide a tapered shape, one or more wedges (not
shown) may be cut out of the band to provide a desired tapered but
annular shape. In another option, portions of the core may be
disconnected from other portions, e.g., to prevent puckering. For
example, if the core is formed from a rolled sheet (not shown),
ends of the sheet (also not shown) may remain loose to allow the
ends to move relative to one another.
[0078] In a relaxed state (free from external forces), the sewing
cuff 20 may adopt an undulating annular shape or a generally planar
annular shape. The sewing cuff 20 may also be tapered, as shown in
FIGS. 1 and 2, e.g., having a larger diameter or circumference
about an upper edge than about an edge adjacent the annular ring
18. The tapered shape of the sewing cuff 20 may define an angle
relative to the longitudinal axis 17, e.g., between about twenty
and forty five degrees (20-45.degree.).
[0079] The material of the core may be substantially flexible,
e.g., manufactured in a desired annular shape, yet easily deformed,
e.g., deflected, stretched, and/or compressed. The core may be
sufficiently flexible to be "floppy," i.e., such that the core
conforms easily to the particular anatomy and/or implantation
arrangements encountered during implantation. Thus, when the sewing
cuff 20 is placed above or within a biological annulus within a
patient's heart, the core may conform to the surrounding anatomy
and/or may deform when the valve member 14 is secured to the gasket
member 12, e.g. to enhance sealing between the valve member 14 and
the gasket member 12, as described further below. Additional
information on flexible cores or other constructions of the sewing
cuff 20 may be found in U.S. Publication No. US 2006/0195184, filed
as Ser. No. 11/069,081, the entire disclosure of which is expressly
incorporate by reference herein.
[0080] With continued reference to FIGS. 1 and 2, the leaders 50
may include elongate rails, fibers, or filaments including a first
or distal end 51 attached or otherwise secured to the gasket member
12 and a second or proximal end 52. Optionally, the leaders 50 may
include one or more markers or other elements (not shown) spaced
apart along at least a portion of their lengths, e.g., immediately
adjacent the first end 51. In addition or alternatively, as shown
in FIG. 4, the leaders 50 may include one or more unidirectional or
bidirectional retention elements 54, e.g., locking beads, tabs,
ratchets, detents, and the like. As explained further elsewhere
herein, these leaders may also provide connectors for attaching
and/or securing the valve member 14 to or adjacent the gasket
member 12.
[0081] The leaders 50 may be threads, filaments, wires, rails, or
other tethers that extend from the gasket member 12. For example,
the leaders 50 may be monofilaments or multifilament structures,
e.g., braided, spun, or otherwise formed into a unitary member. The
leaders 50 may be formed from wire or suture materials, e.g.,
plastic, such as polyethylene, metal, such as stainless steel, cat
gut, or composite materials, using known methods. The leaders 50
may be stiff or flexible, and/or may be resiliently bendable or
plastically pliable. The retention elements 54 may be integrally
formed on the leaders 50, e.g., at the time the leaders 50 are
formed, or may be separate elements (made from the same or
different materials than the leaders 50) that are bonded, fused, or
otherwise attached to the leaders 50 at predetermined locations.
Alternatively, the leaders 50 may be flat bands, e.g., formed from
plastic or other material, and may have the retention elements 54
formed therein or attached thereto, as described elsewhere
herein.
[0082] With continued reference to FIG. 4, the retention elements
54 may include tapered proximal edges 54a and substantially blunt
distal edges 54b. The proximal edges 54a may provide a
substantially smooth transition allowing the valve member 14 to be
passed distally over the retention elements 54. The distal edges
54b may provide locks that prevent the valve member 14 from being
passed proximally back over the retention elements 54, similar to a
ratchet or detent, as described further below. In alternative
embodiments, the retention elements on the leaders 50 may include
knots (not shown) tied onto the leaders 50 and/or beads (also not
shown) formed on the leaders 50 at predetermined locations.
Although only one retention element 54 is shown on each leader 50,
optionally, multiple retention elements 54 may be provided spaced
apart from one another along each leader 50.
[0083] Each leader 50 may be attached to, pre-threaded through, or
otherwise placed on the gasket member 12, e.g., at spaced apart
intervals from one another. For example, leaders 50 may be provided
on the gasket member 12 that are aligned with the commissures (not
shown) on the valve member 14 and/or a biological annulus into
which the gasket member 12 is to be implanted. Thus, for example,
for a prosthesis for an aortic valve having three commissures,
three leaders 50 may be provided, as shown.
[0084] Each leader 50 may be attached to the gasket member 12 by
directing the first end 51 through a predetermined location in the
gasket member 12 and melting or otherwise expanding the first end
51 (e.g., similar to a rivet or nail head) to prevent subsequent
removal. Alternatively, the first end 51 may be looped back around
the leader 50 and bonded, fused, tied, or otherwise secured to the
leader 50. In another alternative, the first end 51 may be pulled
and secured or disposed adjacent the second end 52 (not shown),
e.g., similar to a double-arm suture. The leaders 50 may be
attached to the fabric of the sewing cuff 20 immediately adjacent
the annular ring 18, or to other portions of the gasket member 12,
e.g., to the annular ring 18, the core of the sewing cuff (not
shown), or other portions of the fabric covering of gasket member
12.
[0085] Optionally, the gasket member 12 may include one or more
additional components. For example, the gasket member 12 may
include a collar or stand-off 58 that extends upwardly from the
sewing cuff 20 for receiving the valve member 14, such as that
shown in FIG. 8C. In addition or alternatively, a skirt or a
plurality of baleen elements (not shown) may be provided around or
adjacent the annular ring 18, e.g., that may bias a portion of the
fabric covering outwardly (also not shown). Additional information
on materials, construction, and/or components of the gasket member
112 may be found in U.S. Publication Nos. US 2004/0122516, filed as
Ser. No. 10/327,821, US 2005/0165479, filed as Ser. No. 10/765,725,
US 2006/0195184, filed as Ser. No. 11/069,081, and US 2007/0016285,
filed as Ser. No. 11/420,720, and in co-pending application Ser.
No. 11/567,735, filed Dec. 6, 2006. The entire disclosures of these
references are expressly incorporated by reference herein.
[0086] Turning to FIGS. 3A and 3B, the gasket member 12 may be
expandable and/or compressible such that the cross-section of the
gasket member 12 may be adjusted, e.g., to accommodate introduction
into a patient's body during a procedure, as described further
elsewhere herein. In one embodiment, the annular ring 18 may be
biased to a relaxed or expanded condition, e.g., defining a
predetermined diameter "D1" (as shown in FIG. 3A). At least a
portion of the annular ring 18 may be contracted radially inwardly
to define a smaller diameter or cross-section "D2" (as shown in
FIG. 3B), e.g., to facilitate delivery into a biological annulus.
As described above, the sewing cuff 20 may be substantially
flexible such that the sewing cuff 20 is also compressed radially
inwardly as the annular ring 18 is compressed. Thus, the gasket
member may be compressible, yet may be resiliently expandable to
dilate tissue surrounding the annulus and/or to facilitate securing
the gasket member 12 within a biological annulus.
[0087] To contract the gasket member 12, tension may be applied to
the leaders 50 (e.g., using delivery tool 60, described further
below), e.g., to draw one or more portions of the gasket member 12
inwardly towards the central axis 17. For example, inward and/or
proximal tension may be applied to the leaders 50, e.g., by pulling
the leaders 50 at least partially into the delivery tool 60, as
described further below, which may pull the ends of the leaders 50
inwardly towards the central axis 17. As the leaders 50 are
tensioned, the annular ring 18 may contract inwardly to assume a
multiple lobular shape, e.g., as shown in FIG. 3B, such that the
gasket member 12 assumes the contracted condition.
[0088] The annular ring 18 may deform elastically towards the
contracted condition. Alternatively, as described elsewhere herein,
the annular ring 18 may be cooled to a martensitic state, e.g., by
immersing the gasket member 12 in ice, ice water, or other fluid
maintained at a temperature below the final martensitic temperature
of the annular ring 18. In this alternative, the annular ring 18
may be plastically deformed while the annular ring 18 is in the
relatively soft, martensitic state.
[0089] When tension of the leaders 50 is released, e.g. by
releasing the leaders 50 at least partially from the delivery tool
60, the annular ring 18 may resiliently expand outwardly, e.g., to
a shape having a generally circular cross-section, thereby
returning the gasket member 12 towards the expanded condition,
e.g., as shown in FIG. 3A. For example, if the annular ring 18 is
deformed elastically to the contracted condition, the annular ring
18 may simply expand resiliently towards the expanded condition.
Alternatively, if deformed in a martensitic state, the gasket
member 12 may be heated such that the annular ring 18 resumes an
austenitic state, e.g., when the annular ring 18 is exposed to
ambient temperatures or body temperature. In this alternative, the
annular ring 18 may "remember" the expanded condition and become
biased to expand upon being released.
[0090] Turning to FIG. 2, an exemplary embodiment of an apparatus
or system 30 is shown for delivering a prosthesis into a biological
annulus that includes a gasket member 12 and a delivery tool 60.
The gasket member 12 may be any of the embodiments described
herein, e.g., including an annular ring 18, a sewing cuff 20, and a
plurality of elongate leaders 50. The delivery tool 60 generally
includes a shaft 62 having a proximal end 61, a distal end 63 sized
and/or shaped for introduction into an opening in a patient's body,
and a handle 65 on the proximal end 61. The delivery tool 60 may
also include one or more lumens 67 (one shown in phantom) extending
between the proximal and distal ends 61, 63, e.g., for receiving
portions of the leaders 50 therein. Alternatively, the shaft 62 may
include other configurations, e.g., a "U" shaped cross-section
defining a channel for receiving the leaders 50 therein. Such a
cross-section may facilitate loading the leaders onto the delivery
tool 60.
[0091] The handle 65 may also include one or more actuators 66, 68,
e.g., one or more locking, tightening, and/or loosing mechanisms
for manipulating the leaders 50. For example, the delivery tool 60
may include a locking mechanism 64 for releasably securing the
second ends of the leaders 50, e.g., one or more clamping
structures, detents, and the like. In addition or alternatively,
the actuators 66, 68 may allow the second ends of the leaders 50 to
be directed proximally or distally, e.g., to apply or release
tension, as described further below. As shown, the locking
mechanism 64 includes a lever 66 that may be actuated to release
the second ends of the leaders 50, and a latch 68 that may be
actuated to increase and/or decrease tension applied to the leaders
50.
[0092] For example, the leaders 50 may be loaded into the distal
end 63 of the delivery tool 60 and through the lumen 67 until the
second ends are engaged or otherwise received by the locking
mechanism 64. Optionally, the leaders 50 may be loaded by a user
shortly before a procedure, e.g., allowing a gasket member 12 of a
desired size "D1" to be selected and loaded onto the delivery tool
60. Alternatively, the leaders 50 may be preloaded into a delivery
tool 60 during manufacturing, although this may require providing
multiple delivery tools 60 before a procedure, each carrying a
different size gasket member 12.
[0093] When it is desired to compress the gasket member 12, the
latch 68 may be actuated to pull the leaders 50 proximally a
predetermined distance within the delivery tool 60. This action may
pull the gasket member 12 proximally against the distal end 63 of
the delivery tool 60 and/or radially inwardly, as shown in FIG. 3B.
The tension may be selected to compress the gasket member 12 to a
predetermined size and/or shape. As shown in FIG. 3B, the gasket
member 12 has been compressed into a three lobe clover-like shape
having a cross-section "D2." The tension may be applied by a user
shortly before introducing the gasket member 12 into a patient or
the tension may be preloaded, e.g., during manufacturing.
[0094] When it is desired to deploy the gasket member 12, the lever
66 may be actuated, thereby releasing the leaders 50 from the
delivery tool 60. Alternatively, the tension on the leaders 50 may
be released by actuating the latch 68, e.g., in the opposite
direction, from that used to apply the tension, without releasing
the leaders 50 entirely from the delivery tool 60. In a further
alternative, the lever 66 and latch 68 may be combined into a
single actuator having multiple settings or positions, depending
upon the action desired (e.g., tension, tension release, fully
release).
[0095] It will be appreciated that other constraints and/or
delivery tools may be provided to compress and/or maintain the
gasket member 12 in a contracted condition. For example, a delivery
tool (not shown) may be provided that includes a tubular body or
other structure into which the entire gasket member 12 may be
loaded, e.g., after compressing the gasket member 12 to the
contracted condition. The delivery tool may include a plunger or
other device (not shown) within the tubular body that may be used
to deploy the gasket member 12 from the tubular body. In an
exemplary embodiment, the gasket member 12 may be compressed by
flattening the annular ring 18 along the plane 16 and then folding
or rolling the resulting flattened annular ring 18. For example,
after flattening the annular ring 18, the annular ring 18 may be
rolled into a spiral, folded in half, e.g., into a "C" shape, such
as that shown in FIG. 12, or otherwise compressed. When the gasket
member 18 is deployed from the delivery tool, the annular ring 18
may resiliently return to its expanded condition, similar to the
other embodiments described elsewhere herein. Additional
information regarding apparatus and methods for using such as
gasket member and/or heart valve assembly may be found in U.S.
Publication No. 2007/0016288, filed as Ser. No. 11/457,437, the
entire disclosure of which is expressly incorporated by reference
herein.
[0096] Returning to FIGS. 1 and 2, the valve member 14 generally
includes an annular shaped body or frame 32 and one or more valve
elements 33. The valve member 14 may include a fabric covering 35,
similar to the gasket member 12, e.g., covering the frame 32 and/or
other components of the valve member 14. The frame 32 may have a
noncircular, e.g., multiple lobular shape corresponding to a shape
of the biological annulus within which the valve member 14 is to be
implanted. For example, the valve member 14 may have a tri-lobular
shape, including three lobes separated by cusps or scallops, e.g.,
corresponding to a sinus of Valsalva above an aortic valve site. In
one embodiment, the valve member 14 may be a bioprosthetic valve
member, e.g., an annular frame 32 carrying a plurality of tissue
leaflets 33. The frame 32 may include a plurality of struts (also
not shown for clarity) that may be attached to and/or otherwise
carry the leaflets 33. For example, the struts may include a
laminate structure, including two or more sheets of flexible
material, similar to the valves disclosed in U.S. Pat. No.
6,371,983, and U.S. Publication No. US 2006/0276888, filed as Ser.
No. 11/144,254, the entire disclosures of which are expressly
incorporated by reference herein.
[0097] Alternatively, the valve member 14 may be a connecting
device to which a valve (not shown) may be connected or that may
otherwise receive a valve component, such as the connection adapter
elements shown in U.S. Publication No. US as 2005/0043760, filed as
Ser. No. 10/646,639, the entire disclosure of which is expressly
incorporated by reference herein. In another alternative, the valve
14 may include a mechanical valve or other valve (not shown), such
as those disclosed in US 2005/0165479 and US 2007/0016285725,
incorporated by reference above.
[0098] Turning to FIGS. 6 and 7, optionally, the valve member 14
may include one or more introducers or receivers 76 through which
leaders 50 may be received. For example, as shown in FIG. 6, a
first embodiment of an introducer 76 is shown that includes a
tubular member 76 received through a portion of the valve member
14. For example, the tubular members 76 may simply be removably
inserted through predetermined regions of a fabric covering on the
frame 32, e.g., such that the tubular members 76 extend
substantially parallel to the longitudinal axis 17. As shown, the
tubular members 76 are located at commissures 34 of the frame 32,
although alternatively, the tubular members 76 may be located at
other desired angular locations around the frame 32 corresponding
to the locations of the leaders 50 on the gasket member 12 (not
shown in FIG. 6; see, e.g., FIG. 1).
[0099] The tubular members 76 may be formed from a variety of
materials, e.g., a section of hypotube, made from metal, such as
stainless steel, plastic, or composite materials. The tubular
members 76 may be preloaded onto the frame 32, e.g., during
manufacturing, or loaded onto the frame 32 shortly before a
procedure. As described further below, the tubular members 76 may
be removed from the frame 32 at any time, e.g., immediately before
or after securing the valve member 14 to the gasket member 12.
[0100] FIG. 7 shows another embodiment of introducers 76' that may
be provided directly on the valve member 14. As shown, for example,
the introducers 76' are formed from a piece of fabric or other
material 78' attached to the fabric covering the valve member 14,
thereby defining a pocket or passage 79' therethrough. The
introducers 76' may be a rectangular section of material whose side
edges are stitched, bonded, or otherwise attached to the fabric
covering or other portion of the valve member 14, or a separate
tubular structure. In yet another embodiment, the leaders 50 may be
introduced through the fabric itself of valve member 14, e.g.,
using a needle or other tool (not shown) on the second ends of the
leaders 50 to "pick up" one or more threads of the fabric.
Additional information on introducers or receivers may be found in
US 2005/0165479, incorporated by reference herein.
[0101] Turning to FIGS. 5A-5C, during use, the heart valve assembly
10 may be implanted within a patient's body, e.g., within or
adjacent to a biological annulus 90. The biological annulus 90 may
be the site for replacing an existing natural or previously
implanted heart valve, such as a tricuspid, mitral, aortic, or
pulmonary valve within a patient's heart (not shown).
[0102] Before implanting the heart valve assembly 10, the patient
may be prepared for the procedure using known methods. For example,
the patient may be placed on cardiopulmonary bypass (CPB), and the
patient's heart may be exposed, e.g., by sternotomy, thoracotomy,
or other open or minimally invasive procedure. An incision may be
created in the blood vessel above the valve being replaced (not
shown), e.g., the aorta for an aortic valve replacement, in order
to access the annulus 90. The existing natural or prosthetic heart
valve and/or leaflets (also not shown) may be removed from the
annulus 90 using known methods.
[0103] A heart valve assembly 10, e.g., including a gasket member
12 and a valve member 14, may be selected based upon the anatomy
encountered, e.g., having a plurality of lobes, matching the lobes
of the biological annulus 90 and/or having a cross-sectional
dimension corresponding to the interior cross-section of the
biological annulus 90. Optionally, a gasket member 12 and/or valve
member 14 may be selected having a size that is larger than the
biological annulus 90. For example, the gasket member 12 may have a
diameter in its relaxed condition that is slightly larger than the
biological annulus 90, e.g., such that the gasket member 12 may at
least partially dilate the biological annulus 90 upon implantation.
In addition or alternatively, the valve member 14 may have a
diameter or other cross-section that is substantially larger than
the biological annulus 90, e.g., for supra-annular or intra-sinus
implantation, which may accommodate the larger size.
[0104] With reference to FIG. 5A, initially the gasket member 12
may be restrained in the contracted condition, e.g., by the
delivery tool 60. For example, as described above, the gasket
member 12 may include leaders 50 and the delivery tool 60 may be
provided with the leaders 50 preloaded into the delivery tool 60.
The leaders 50 may be provided initially in a relaxed state, i.e.,
without subjecting the gasket member 12 to any tension or other
stress, e.g., to prevent fatigue of components and/or materials of
the gasket member 12. Immediately before use, the user (e.g., a
physician, physician's assistant, nurse, or other medical
professional) may actuate the latch 68 to apply tension to the
leaders 50, e.g., to compress the gasket member 12 inwardly to the
contracted condition shown in FIG. 5A. Optionally, before
compressing the gasket member 12, the gasket member 12 may be
placed in ice water or otherwise chilled, e.g., to "soften" or
place the annular ring 18 in a martensitic state, as described
elsewhere herein. In addition or alternatively, the predetermined
tension may pull the gasket member 12 onto or around the distal end
63 of the delivery tool 60, thereby stabilizing and/or securing the
gasket member 12 relative to the distal end 63, e.g., to facilitate
introduction into the patient's body. Alternatively, the leaders 50
may be pre-tensioned by the delivery tool 60 before use, e.g.,
during manufacturing, as described above.
[0105] In an alternative embodiment, the user may load the leaders
50 into the deliver tool 60 immediately before the procedure, and
then apply the desired tension to compress and/or stabilize the
gasket member 14. This alternative may be particularly desirable
when a single delivery tool 60 is used to deliver one of various
sized gasket members available to the user. Thus, once the
implantation site is exposed, the physician may measure the size of
the biological annulus 90 and select an appropriate gasket member
12 (and/or valve member 14) based upon the specific anatomy
encountered.
[0106] Once constrained in the contracted condition, the gasket
member 12 may be introduced into the patient's body and advanced
into the biological annulus 90, e.g., by directing the distal end
63 of the delivery tool 60 into the patient's body. The gasket
member 12 may be advanced until the annular ring 18 extends at
least partially into the biological annulus 90. In one embodiment,
the annular ring 18 may extend through the biological annulus 90,
i.e., with a lower edge of the annular ring 18 disposed within the
sub-annular space below the biological annulus 90. Optionally, the
gasket member 12 may include a flexible skirt (not shown) that may
surround and/or extend from the annular ring 18 through the
biological annulus 90. The skirt may be biased to extend outwardly
to provide a smooth transition and/or enhance a seal between the
gasket member 12 and the biological annulus 90.
[0107] Turning to FIG. 5B, the gasket member 12 may then be
expanded or at least partially released within the biological
annulus 90, e.g., to dilate the biological annulus 90 or otherwise
direct the surrounding tissue 98 outwardly. For example, the latch
68 on the delivery tool 60 (not shown, see FIG. 2) may be actuated
to remove the tension on the leaders 50, whereupon the annular ring
18 may resiliently expand against the tissue surrounding the
biological annulus 90. This may substantially stabilize or secure
the gasket member 12 relative to the biological annulus 90. Once
stabilized, the leaders 50 may be released entirely from the
delivery tool 60, e.g., by actuating lever 66 (not shown, see FIG.
2). In an alternative embodiment, a dilation tool (not shown) may
be advanced into the gasket member 12 and expanded to forcibly
(e.g., plastically) expand the annular ring 18 within the
biological annulus 90.
[0108] With the annular ring 18 deployed within the biological
annulus 90, the sewing cuff 20 may contact the tissue surrounding
the supra-annular space above the biological annulus 90, as shown
in FIG. 5B. One or more fasteners 96, e.g., clips, staples,
sutures, and the like, may be directed through the gasket member 12
into the tissue 98 above and/or surrounding the biological annulus
90. For example, as shown, a plurality of clips 96 may be driven
through the sewing cuff 20 into the surrounding tissue 98, similar
to the method shown in FIGS. 14A-14C and described elsewhere
herein. Exemplary fasteners and methods for using them to secure
the gasket member 112 may be found in U.S. Publication Nos. US
2004/0122516, filed as Ser. No. 10/327,821, US 2005/0043760, filed
as 10/646,639, US 2005/0080454, filed as Ser. No. 10/681,700, and
US 2006/0122634, filed as Ser. No. 11/004,445, the entire
disclosures of which are incorporated by reference herein.
[0109] Turning to FIG. 5B, with the gasket member 12 within the
biological annulus 90, the valve member 14 may then be advanced
into the patient's body towards the biological annulus 90. In the
embodiment shown, the valve member 14 may be advanced along the
leaders 50 toward the gasket member 12. Before advancing the valve
member 14, the second or free ends 52 of the leaders 50 may be
directed through respective portions of the valve member 14. Thus,
before advancing the valve member 14, the leaders 50 need to be
released and/or removed completely from the delivery tool 60, as
described above.
[0110] In the exemplary embodiment shown in FIG. 5B, the leaders 50
may be directed through respective portions of the fabric covering
35, e.g., adjacent the commissures 34. For example, the second ends
52 of the leaders 50 may include needles (not shown) that may be
directed through desired portions of the fabric covering 35 to pick
up one or more threads. Optionally, the valve member 14 may include
receptacles (not shown) attached to the frame 32 and/or fabric
covering 35, and the fabric covering 35 may include slits or other
openings through which the leaders 50 may be introduced to pass the
leaders 50 through the receptacles, e.g., similar to the
embodiments shown in FIGS. 20A-20E and FIGS. 24A-26 and described
elsewhere herein.
[0111] Alternatively, as shown in FIG. 6, if the valve member 14
includes introducers 76, the second ends 52 of the leaders 50 may
be backloaded through respective introducers 76. In a further
alternative, shown in FIG. 7, the valve may include receivers 76'
through which the leaders 50 may be directed.
[0112] With the leaders 50 received through the valve member 14,
the valve member 14 may be advanced distally over the leaders 50
towards the gasket member 12, i.e., in the direction of arrow 94,
until the valve member 14 engages or otherwise contacts the gasket
member 12. As shown in FIG. 5B, the leaders 50 may include
ratcheting or other retention elements 54 over which the valve
member 14 may pass. For example, the retention elements 54 may
include tapered proximal edges 54a, which may provide a smooth
transition that allows the retention elements 54 to pass freely
through the fabric covering 35, receptacles (not shown), or
introducers 76, 76.' Because of the blunt distal edges 54b,
however, the valve member 14 may not be withdrawn back over the
retention elements 54. Thus, the retention elements 54 may allow
unidirectional advancement of the valve member 14, i.e., towards
the gasket member 12.
[0113] In an exemplary embodiment, the retention elements 54 may be
disposed a predetermined distance from the first ends 51 of the
leaders 50, thereby securing the valve member 14 against or
immediately adjacent the gasket member 12. The predetermined
distance may be set such that the frame 32 of the valve member 14
substantially contacts the sewing cuff 20, e.g., to at least
partially compress the core, which may enhance sealing between the
valve member 14 and the gasket member 14.
[0114] In addition or alternatively, one or more knots may be
directed down the leaders 50 after the valve member 14 engages or
contacts the gasket member 12. In another alternative, if the
gasket member 12 includes a collar (not shown, see, e.g., FIG. 8C)
extending above the sewing cuff 20, the collar may include a
drawstring or other connector(s) (also not shown) that may be
tightened around the frame 32 of the valve member 14 to secure the
valve member 14 relative to the gasket member 12. In further
alternatives, the valve member 14 and/or gasket member 12 may
include one or more cooperating connectors, e.g., clips, detents,
and the like, that may self-engage when the valve member 14 is
docked to the gasket member 12, similar to the embodiments
described in the references incorporated by reference above.
[0115] Turning to FIG. 5C, once the valve member 14 is secured to
the gasket member 12, the leaders 50 may be cut or otherwise
severed, thereby providing a heart valve assembly 10 implanted
within the biological annulus 90. As shown, the leaders 50 are
severed above the retention elements 54 used to secure the valve
member 14 to the gasket member 12. If the leaders 50 are knotted to
secure the valve member 14 to the gasket member 12, the leaders 50
may be severed above the knots. Optionally, the leaders 50 may
include weakened regions (not shown) above the retention elements
54 or otherwise disposed a predetermined distance from the first
ends 51. When a predetermined tension is applied to the leaders 50
(greater than that used to compress and/or secure the gasket member
to the delivery tool 60), the weakened regions may automatically
fail, thereby separating the first ends 51 from the remainder of
the leaders 50, which may then be removed from the patient's body.
This alternative may eliminate the need to introduce scissors or
other cutting tools into the patient to cut the leaders 50. If
desired, e.g., in an acute emergency situation or if the valve
member 14 is being replaced, the remaining leaders may be cut below
the retention elements 54 to release the valve member 14, allowing
the valve member 14 to be removed from the gasket member 12 and/or
patient's body.
[0116] With additional reference to FIG. 6, if the valve member 14
includes removable introducers 76, the introducers 76 may be
removed from the valve member 14 immediately before, while, or
immediately after the valve member 14 is secured to the gasket
member 12. For example, the introducers 76 may be removed simply by
directing the introducers 76 proximally over the leaders 50, i.e.,
out of the fabric or frame of the valve member 14 and over the
second ends 52 of the leaders 50. Alternatively, as shown in FIG.
7, the introducers 76' may be pockets formed from fabric, metal, or
polymeric material, separately attached or integrated with the
frame 32 and/or fabric covering 35 of the valve member 14. In this
alternative, the introducers 76' may interact with the retention
elements 54 on the leaders 50 to prevent removal of the valve
member 14 away from the gasket member 12.
[0117] Turning to FIGS. 8A and 8B, another embodiment of a gasket
member 112 is shown that includes an annular ring 118, a sewing
cuff 120, and a plurality of elongate guide rails or other leaders
150 extending from the sewing cuff 120 or other portion of the
gasket member 12, e.g., similar to other embodiments herein.
Optionally, the gasket member 112 may also include a flexible skirt
and/or baleen elements (not shown), e.g., surrounding the annular
ring 118. A fabric covering may be provided on one or more
components of the gasket member 112, e.g., over the annular ring
118 and over a core of the sewing cuff 120, also as described
elsewhere herein.
[0118] In addition, the gasket member 112 includes a plurality of
guide shields 156 removably attached to the gasket member 112,
e.g., by one or more sutures to the sewing cuff 120. The guide
shields 156 may extend upwardly and/or outwardly from the sewing
cuff 120, e.g., to at least partially define a passage 124 for
guiding a valve prosthesis (not shown) downwardly towards the
gasket member 112, as described further below. In a relaxed
condition, the guide shields 156 may extend diagonally outwardly
from the gasket member 112, but may be deflectable radially
inwardly towards a central axis 117 of the gasket member 112, e.g.,
during delivery.
[0119] The guide shields 156 may be formed from a relatively thin
and/or transparent sheet, e.g., a plastic such as polyester or
Mylar or any other polymeric film or material, such as high-density
or low-density polyethylene, polystyrene, and the like. The sheet
may be cut or otherwise formed to include one or more bands, e.g.,
defining a relatively wide base that may be attached to the gasket
member 112 and a relatively narrow loose upper end. For example, as
shown in FIG. 8A, the guide shields 156 may have a generally
triangular shape, e.g., with a wider base 156a and a narrower upper
end 156b. Optionally, as shown, a center of the guide shields may
be removed to provide diagonal or inverted "V" bands extending from
the upper end 156b down to the base 156a. Alternatively, the guide
shields 156 may have a substantially continuous "mandolin" or
inverted "Y" shape, as shown in FIG. 8B, and described further in
co-pending application Ser. No. 60/914,742, incorporated by
reference herein.
[0120] Optionally, the upper ends 156b may include one or more
features that partially restrain the guide rails 150 away from the
passage 124 or otherwise out of the operator's field of view during
a procedure. For example, as shown in FIG. 8A, the upper ends 156b
may include one or more bands 159 that may be wrapped around the
guide rails 150 to releasably constrain the guide rails 150 to the
guide shields 156. In addition or alternatively, as shown in FIG.
8B, the upper ends 156b may include openings 158 that may receive
the guide rails 150. Optionally, the upper ends 156b of the guide
shields 156 may be split, e.g., at 158a down to the openings 158 or
diagonally from the openings 158 (not shown), to facilitate
inserting and/or removing the guide rails into/from the openings
158, as shown in FIG. 8B.
[0121] The guide shields 156 may be attached to the sewing cuff
120, e.g., by one or more sutures (not shown) sewn through fabric
of the sewing cuff 120 (and/or other portion of the gasket member
12) and holes (also not shown) in the base 156a. Optionally, a
chain stitch or other stitch may be used, e.g., that may unravel
upon being cut at a single location, which may facilitate removing
the sutures and, consequently, the guide shields 156 after
implantation. Additional information on methods for removably
attaching the guide shields 156 to the gasket member and/or methods
for using the guide shields 156 may be found in co-pending
application Ser. No. 60/914,742, incorporated by reference
herein.
[0122] Turning to FIGS. 9A-9C, an exemplary embodiment of a gasket
delivery tool 160 is shown that generally includes an elongate
shaft 162 including a proximal end 161, a distal end 163, and an
actuator 165 on the proximal end 161. With additional reference to
FIGS. 10A and 10B, the delivery tool 160 includes a plurality of
supports 166 on the distal end, e.g., spaced apart around a
longitudinal axis 167 of the tool 160. The supports 166 may be
substantially rigid cylindrical hubs for receiving a gasket member
112 (such as any of those described herein) around the supports
166. The supports 166 may generally define a diameter that is
smaller than the gasket member 112, e.g., smaller than the radius
of the annular ring 118. The supports 166 may be formed as a single
piece, e.g., integrally molded, machined, and the like, or may be
separate shafts and/or other components attached to one another
and/or the distal end 163 of the gasket delivery tool 160.
Alternatively, a hub or base having a circular or other multiple
lobed shape may be provided instead of the supports 166, if
desired.
[0123] In addition, the tool 160 includes a plurality of arms 168
movably mounted to the distal end 163. For example, one end 168a of
the arms 168 may be attached to the distal end 163 of the tool 160,
e.g., proximal to the supports 166, and the other free end may
include tips 168b disposed adjacent the supports 166. As shown, the
arms 168 may be offset radially relative to the supports 166 such
that each arm 168 is disposed between adjacent supports 166. The
arms 168 may be movable from an outer position, e.g., as shown in
FIGS. 9A and 9B, defining a radius larger than the gasket member
112 to an inner position, e.g., as shown in FIGS. 10A and 10B,
wherein the tips 168b are disposed between and/or within the
supports 166.
[0124] The actuator 165 may include a lever or other mechanism that
may selectively move the tips 168b of the arms 168 between the
outer and inner positions. For example, as shown in FIGS. 9A and
9B, the actuator 165 may include a handle 165a coupled to a sleeve
165b via a linkage 165c. The handle 165a may be biased outwardly,
e.g., by a spring 165d or other biasing mechanism, thereby
maintaining the arms 168 in the outer position. The handle 165a may
be directed towards the shaft 162, e.g., about pivot point 165e,
thereby directing linkage 165c and sleeve 165b distally, i.e.,
towards the distal end 163. This action causes the tips 168b of the
arms 168 to move inwardly towards the inner position.
[0125] For example, the arms 168 may be deflectable radially
inwardly by an inward force applied to the arms 168 as the sleeve
165b passes over the first ends 168a. The arms 168 may be
sufficiently resilient to return outwardly when the sleeve 165b is
retracted from over the first ends 168a. Alternatively, the arms
168 may include hinges or other components coupled to the sleeve
165b and/or linkage 165c such that the arms 168 are movable
inwardly and outwardly.
[0126] The handle 165a may be temporarily locked against the shaft
162 with the arms 168 in the inner position, e.g., by a lock or
other interlocking features (not shown) on the handle 165a, linkage
165c, and/or shaft 162. For example, the linkage 165c may include a
slot 165f and the handle 165a may include a sliding button, switch
or other control 165g that includes a cross pin 165h that may be
received in the slot 165f when the handle 165a is directed against
the shaft 162. The control 165g may be manually moved to engage
and/or disengage the cross pin 165h and the slot 165f Optionally,
the control 165g may be biased, e.g., towards or away from the end
of the handle 165a, for example by a spring (not shown), such that
when the handle 165a is directed against the shaft 162, the cross
pin 165h slides into the slot 165f, preventing subsequent movement
of the handle 165a. The control 165g may be directed against the
bias of the spring, e.g., distally or proximally, to release the
cross pin 165h from the slot 165f, whereupon the spring 165d may
then bias the handle 165a outwardly. Thus, the slot 165f may be
oriented to engage with the cross pin 165h as the control 165g is
translated along the handle 165a in a distal or proximal direction,
and to release the cross pin 165h as the control 165g is translated
in an opposite proximal or distal direction. When it is desired to
release the handle 165a and arms 168 back to the outer position,
the control 165g may be released, whereupon the spring 165d may
then bias the handle 165a outwardly, thereby automatically opening
the arms 168 towards the outer position. Alternatively, the levers
involved may be designed such that the bias of the spring 165d is
removed when the handle 165a is directed against the shaft 162,
thereby maintaining the arms 168 in the inner position. In this
alternative, the handle 165a may simply be pulled away from the
shaft 162 such that the spring 165d again biases the handle 165a to
move outwardly, directing the arms 168 to the outer position.
[0127] During use, with the arms 168 in the outer position, a
gasket member 112 may be placed between the supports 166 and the
arms 168, e.g., with the nadir regions of the sewing cuff 120
aligned radially with the arms 168 and the commissure regions of
the sewing cuff 120 aligned radially with the supports 166. The
arms 168 may then be directed to the inner position, thereby
securing the gasket member 112 between the supports 166 and the
arms 168. As shown in FIGS. 10A and 10B, the gasket member 112 may
be deformed from a generally circular expanded condition to a
multiple lobed, e.g., "shamrock" shaped contracted condition
defining lobes, similar to the other embodiments and tools
described above. The gasket member 112 may be elastically deformed
into the contracted condition or plastically deformed, e.g., in a
martensitic state, similar to the previous embodiments.
[0128] Turning to FIGS. 11A-11E, during use, the tool 160 may be
loaded with the gasket member 112, as shown in FIG. 11A, and then
directed into a biological annulus 90, e.g., as best seen in FIG.
11B. As shown in FIG. 11C, the tool 160 may be rotated about its
longitudinal axis 167 to align the lobes or "ears" of the gasket
member 112 with the commissures 91 of the biological annulus 90.
Turning to FIGS. 11D and 11E, the arms 168 may then be directed to
the outer position, thereby releasing the gasket member 112.
[0129] As shown in FIG. 11E, the gasket member 112 may resiliently
expand towards its original expanded condition when released,
thereby contacting tissue surrounding the biological annulus 90.
The tool 160 may be removed, leaving the gasket member 112 in place
within the biological annulus 90. As shown, the annular ring of the
gasket member 112 may be located within a native valve annulus,
while the sewing cuff 120 may be located in a supra-annular
position relative to the native valve annulus. If the gasket member
112 includes guide rails 150 and/or guide shields 156, the guide
rails 150 and/or guide shields 156 may extend upwardly from the
biological annulus 90, e.g., to a location above the biological
annulus and/or outside the patient's body, as described elsewhere
herein.
[0130] FIG. 12 shows an alternate contracted configuration for the
gasket member 112, which may be used instead of the multiple lobed
or "shamrock" contracted condition shown in FIG. 10A. As shown in
FIG. 12, the gasket member 112 may be folded into a generally "C"
shaped or rolled shape in the contracted condition, rather than the
multiple lobed condition. Such a folded condition may be maintained
by a tool (not shown), e.g., including one or more arms or other
actuatable members (also not shown), similar to the arms 168 of the
tool 160. Alternatively, the gasket member 112 may simply held by a
needle driver, clamp, or other surgical instrument. Optionally, the
folded ends of the gasket member 112 may be temporarily secured to
one another, e.g., using one or more sutures, a band, and the like
(not shown), which may be removed once the gasket member 112 is
introduced into the biological annulus 90. Upon being released by
the tool, the gasket member 112 of FIG. 12 may resiliently unfold
or otherwise return back to its original annular shape, similar to
when the gasket member 112 is released from the multiple lobed
condition. The folded condition may allow the gasket member 112 to
achieve a smaller cross-section than the multiple lobed condition,
which may be useful when access is limited into the biological
annulus.
[0131] Turning to FIG. 13A, the gasket member 112 is shown
delivered into the biological annulus 90, e.g., using any of the
tools and/or methods described elsewhere herein. The guide shields
156 extend upwardly and/or outwardly from the gasket member 112,
thereby contacting surrounding tissue. The guide shields 156 may be
sufficiently long such that upper ends of the guide shields 156 are
disposed outside the patient's body and/or outside the biological
annulus 90. Optionally, the upper ends 156b of the guide shields
156 may be folded outwardly, e.g., against the patient's chest or
other anatomy, to maintain a passage through the guide shields 156
open and/or move the uppers ends 156b out of the field of view. In
addition or alternatively, the upper ends 156b may also be held by
sutures, clips, clamps, and the like (not shown), e.g., to help
tension or retract the guide shields 156 in order to maintain the
field of view open. The guide shields 156 may at least partially
define a passage communicating with the biological annulus 90, the
inner surfaces of the guide shields 156 providing a smooth and/or
lubricious surface to facilitate advancing a valve prosthesis (not
shown) into the biological annulus 90 towards the gasket member
112, as described further elsewhere herein.
[0132] Turning to FIG. 13B, after releasing the gasket member 112
within the biological annulus 90, the gasket member 112 may be
secured to the surrounding tissue. For example, as shown, a tool
170 may be used to deliver a plurality of fasteners 96 (not shown)
through the sewing cuff 120 and into the surrounding tissue, as
described elsewhere herein. Forceps, tweezers, or other tool 172
may be used, if desired, to manipulate components of the gasket
member 112 during delivery of the fasteners 96. For example, the
tool 172 may be used to hold the sewing cuff 120 and/or to move the
guide rails 150 and/or guide shields 156 out of the way. Because of
the orientation, configuration, and/or transparency of the guide
shields 156, the guide shields 156 may not obscure observation
and/or access into the biological annulus to deliver the fasteners.
FIGS. 14A-14C show additional details of securing the gasket member
112 to the surrounding tissue using fasteners 96.
[0133] Turning to FIGS. 15A-17B, a valve holder tool 210 is shown
that may be used to deliver a valve member 14, which may be any
valve prosthesis described elsewhere herein or in the references
incorporated by reference. For simplicity, only a frame of a valve
member 14 is shown without leaflets or fabric covering. Generally,
the valve holder 210 includes an elongate shaft 212 including a
proximal end 214 and a distal end 216 defining a longitudinal axis
218 therebetween. As best seen in FIGS. 15B and 17B, the valve
holder 210 may include an enlarged head or support 220 on the
distal end 216, which may have a size and/or shape similar to the
valve member 14 carried on the distal end 216. For example, the
head 220 may have a partial dome shape, e.g., defining a cavity
(not shown) under the head 220, which may protect or otherwise
cover leaflets (not shown) of the valve member 14. The head 220 may
include one or more openings 221 therethrough, e.g., for receiving
one or more sutures 13, e.g., as shown in FIG. 17B. As shown, a
suture 13 may be directed through a respective opening 221 and
through fabric of the valve member 14, and then tied off and cut,
thereby securing the valve member 14 to the head 220. Thereafter,
during use, e.g., after implantation, the suture(s) 13 may be cut,
thereby releasing the valve member 14 from the head 220, as
described further below.
[0134] Returning to FIGS. 15A and 15D, the valve holder 210 also
includes a plurality of tubular members 230 including open upper
and lower ends 232, 233. The tubular members 230 may provide guide
passages 230a for receiving guide rails 150 (not shown) of a gasket
member 112 (also not shown), as described further below. The
tubular members 230 may be attached to the shaft 212 of the valve
holder 210, e.g., by hubs 234, 236, such that the tubular members
230 extend generally parallel to the longitudinal axis 218. As
shown, the tubular members 230 include upper ends 232 that are
disposed closer to the longitudinal axis 218 than lower ends 233,
which may facilitate visually monitoring beyond the tubular members
230. Alternatively, the tubular members 230 may extend parallel to
the longitudinal axis 218. In addition or alternatively, the
tubular members 230 may be disposed against or otherwise closer to
the shaft 212, although the distal ends 233 may then curve
outwardly, e.g., in an "S" shape to dispose the distal ends 233
outside the head 220, e.g., as shown in FIG. 15B.
[0135] In addition, the valve holder 210 may include one or more
actuators for causing separation of at least a portion of the guide
rails 150 from the gasket member 112, as described further below.
For example, in one embodiment, each of the tubular members 230 may
be rotatable about an individual central axis 231, as shown in FIG.
15D. The passages 230a through the tubular members 230 may have a
cross-section similar to the guide rails 150, e.g., having an
oblong or rectangular cross-section, which may receive the guide
rails 150 in a fixed angular orientation, while accommodating
relative axial movement. When the tubular members 230 are rotated
about the axes 231, the portion of the guide rails 150 in the
passages may also rotate, thereby causing the guide rails 150 to
plastically deform and break, e.g., adjacent the distal end 233 of
the tubular members 230. Optionally, similar to previous
embodiments, the guide rails 150 may include weakened regions that
may preferentially break upon rotation of the tubular members 230.
The weakened regions may include a notch, slit, groove, cut,
necking, thinning, score mark, and/or narrowing on either or both
edges of the guide rails 150, across the entire width of the guide
rails 150, and/or axially or diagonally along the length of the
guide rails 150. Optionally, a preload force or stress may be
applied on the guide rails 150 when received within the tubular
members 230 that is less than the tensile breaking strength of the
guide rails 150, or, more specifically, less than the tensile
breaking strength at the weakened region(s) of the guide rails 150.
Such a preload may reduce the number of turns of the tubular
members 230 necessary to break or separate the guide rails 150,
e.g., by preventing the guide rails 150 from twisting, binding,
and/or bunching excessively during rotation of the tubular members
230. Thus, each guide rail 150 may be separated by rotating the
respective tubular member 230.
[0136] Alternatively, the entire hub 234 may be rotatable around
the shaft 210, which may cause all of the guide rails 150 to
separate substantially simultaneously at the weakened regions or
other locations adjacent the distal ends 263. In a further
alternative, shown in FIGS. 16A and 16B, the valve holder 210 may
include an actuator 250 that is movable axially relative to the
shaft 212, e.g., from a distal position (shown in FIG. 16A) to a
proximal position (shown in FIG. 16B) for breaking the guide
rails.
[0137] For example, as best seen in FIG. 15C, the actuator 250 may
include an outer housing 252 and an inner member 256 disposed
adjacent the hub 234 in the distal position. The inner member 256
may be coupled to a handle 254, e.g., such that axial movement of
the handle causes the inner member to move axially. The outer
housing 252 may be rotatable relative to the inner member 256,
e.g., for capturing ends of the guide rails 150. The proximal ends
232 of the tubular members 230 may extend into the hub 234 and
communicate with one or more recesses or other features, e.g.,
recess 253a between the outer housing 252 and the inner member 256.
The outer housing 252 and/or inner member 256 may include one or
more locking features, e.g., hooks, catches, ratchets, and the
like, such as catch 253b within the recess 253a that may receive
and/or engage the ends of the guide rails 150.
[0138] With the outer housing 252 open relative to the inner
member, ends of the guide rails 150 may be received within the
recess 253a, e.g., when the guide rails 150 are loaded through the
tubular members 230. The outer housing 252 may then be rotated to
engage the ends of the guide rails 150, e.g., with the catch(es)
253b and/or by at least partially closing the recess 253a to clamp
the ends of the guide rails 150, thereby preventing the guide rails
150 from being separated from the actuator 250. Optionally, similar
to the embodiment shown in FIGS. 23A and 23B, the ends of the guide
rails 150 may include a slot 153 that may receive or otherwise
engage corresponding hooks, catches, ratchets and the like (not
shown) within the recess 253a or otherwise provided on the outer
housing 252 and/or inner member 256.
[0139] During use, a portion of the guide rails 150 may be received
in or otherwise engaged with the actuator 250, e.g., when the guide
rails 150 are loaded through the tubular members 230. When the
actuator 250 is moved from the distal position, shown in FIG. 16A,
towards the proximal position, shown in FIG. 16B, e.g., by pulling
the handle 254, the guide rails 150 may be pulled by the housing
252, thereby causing the guide rails 150 to separate at weakened
regions or otherwise break, e.g. adjacent the distal ends 263 of
the tubular members 230. Optionally, the actuator 250 may include a
lock (not shown) to prevent proximal movement of the actuator 250
until the lock is released. For example, the actuator 250 may be
rotated about the shaft 212 to engage or disengage a lock between
the actuator 250 and the shaft 212.
[0140] This configuration of the valve holder tool 210 may allow
the actuator 250 to be located at a distance proximally from the
head 220. For example, this may facilitate actuation, allowing the
user to actuate the valve holder 210 without having to reach into
the biological annulus. In addition, this configuration of the
valve holder tool 210 may also allow the actuator 250 to be moved a
substantial distance away from the head 220 and the implantation
site. For example, if the shaft 212 were replaced with a flexible
catheter, and the guide rails 150 were sufficiently long and/or
flexible, the valve holder 210 may be used in a percutaneous
implantation or other procedure wherein the actuator is located
outside the patient's body, while the head 220 (and valve 14
thereon) are located within the body at the implantation site,
e.g., as disclosed in US 2007/0016288, incorporated by reference
herein.
[0141] In another alternative, shown in FIGS. 22A and 22B, a valve
holder tool 210' may include a set of cam-lock features 258 for
securing ends of guide rails 150 (not shown, see FIGS. 23A and 23B)
to an actuator 250.' The valve holder tool 210' includes an
elongate shaft 212' including proximal and distal ends 214,' 216,'
a support or head 220' on the distal end 216,' and a plurality of
tubular members 230,' similar to the previous embodiments. An
actuator 250' is slidable on the shaft 212,' e.g., for severing
ends of guide rails 150, similar to the previous embodiment. The
actuator 250 includes an inner member 256' including guide channels
257a' that communicate with tracks 257b.' Openings 257c' above
respective tracks 257b' provide access into the tracks 257b,' if
desired. Each track 257b' includes a tab, detent, catch, or other
feature 257d' as best seen in FIGS. 23A and 23B that may be
received in a hole 153 in an end of a guide rail 150.
[0142] Each cam-lock 258' includes a cap 258a' pivotally mounted to
the actuator 250' by a hinge or element, such that the cap 258a'
may be moved between an open position, e.g., extending away from
the inner member 256' as shown, and a closed position covering a
respective track 257b' and/or opening 257c'. In addition, each
cam-lock 258' includes a tab 258b' or other feature that is
received in the track 257b' when the cap 258a' is moved to the
closed position. Thus, a guide rail 150 may be directed from a
tubular member 230' along the guide channel 257a' into the track
257b,' e.g., until the catch 257c' is received in the hole 153, as
shown in FIGS. 23A and 23B. The cap 258a' may then be closed, the
tab 258b' contacting the guide rail to prevent the catch 257c' from
being removed from the hole 153, thereby securing the end of the
guide rail 150 to the actuator 250.' Optionally, the hole may be
omitted from the guide rail 150 and the catch 257c' may have a
pointed and/or barbed tip that may embed or penetrate through the
end of the guide rail 150, e.g., when the cap 258a' is moved to the
closed position. Once the guide rails 150 are captured in the
tracks 257b' by the caps 258a', the actuator 250' may be
subsequently moved proximally or otherwise manipulated to pull the
guide rails, e.g., to break the guide rails at weakened regions or
elsewhere, similar to the other embodiments described herein.
[0143] Turning to FIGS. 18A-19D, a method is shown for using the
valve holder 210 of FIGS. 15A-17C to deliver a valve 14 into a
biological annulus. The desired valve 14 (which may be any of the
embodiments disclosed herein or in the references incorporated by
reference herein) may be preloaded onto the head 220 of the valve
holder 210 by the manufacturer or the user. Alternatively, a
desired size valve (if multiple sizes are available) may be
selected and loaded onto the head 220 by the user immediately
before or during the procedure, e.g., using one or more sutures 13,
as described above. For example, a valve sizer (or a series of
progressively larger valve sizers) may be directed into the
biological annulus to determine the appropriate size valve
prosthesis to be delivered into the biological annulus.
[0144] Before introducing the head 220 and valve 14 into the
biological annulus, a gasket member (not shown) may be delivered
and/or secured within the biological annulus, e.g., as described
above. As can be seen in FIGS. 18A and 18B, guide rails 150 and
guide shields 156 extend out of the biological annulus from the
gasket member, which cannot be seen.
[0145] Turning to FIG. 18A, the head 220 of the valve holder 210,
carrying the valve 14, may be directed into the biological annulus.
Before doing so, the guide rails 150 may be loaded into the tubular
members 230 of the valve holder 210. Each guide rail 150 may be
loaded through a feature (not shown) of the valve 14 (e.g., as
described elsewhere herein) and into the lower end 233 of the
respective tubular member 230, e.g., until the guide rail 150 exits
the upper end 232 of the tubular member 230.
[0146] For example, as shown in FIGS. 20A-20E, the valve 14 may
include a frame 32 including a plurality of receptacles or other
features 130 configured to receive the guide rails 150
therethrough. Each receptacle 130 may include a cantilever spring
132 including a first end supported by the valve frame 32 and a
second free end including one or more detents 134. As shown in
FIGS. 20A and 20B, the detents 134 may be bent or otherwise formed
to at least partially define a track, slot, or other passage 136
for receiving a guide rail 150 therethrough. The receptacle 130 may
be formed integrally with the valve frame 32, e.g., laser cut or
otherwise formed from a Nitinol or other sheet used to make the
frame 32. Alternatively, other receptacles or connectors may be
provided on the valve 14, such as those disclosed in the references
incorporated by reference above.
[0147] Returning to FIGS. 18A and 18B, the receptacles 130 of the
valve 14 may be aligned with the lower ends 233 of respective
tubular members 230 on the valve holder 210. Thus, to insert the
guide rails 150, the ends of the guide rails 150 may be passed
upwards through the receptacles 130, into the lower ends 233 and
out the upper ends 232 of the tubular members 230. Optionally, the
valve 14 may include guides or other features (not shown) to
facilitate loaded the ends of the guide rails 150 into the
receptacles 130. For example, the fabric covering the valve 14 may
include a slot or other opening that may receive the ends of the
guide rails 150, and direct the guide rails 150 into the
receptacles 130. In addition or alternatively, visual markers may
be provided on the valve 14, e.g., above or around the receptacles
130, to facilitate inserting the guide rails 150 through the valve
14 and into tubular members 230.
[0148] Turning to FIG. 18B, as the head 220 and valve 14 are
directed into the biological annulus, the valve 14 may slidably
contact the guide shields 156 extending from the gasket member (not
shown). The guide shields 156 may thereby provide a substantially
smooth and/or lubricious surface, which may facilitate advancing
the valve 14 into a narrow or partially obstructed biological
annulus.
[0149] As shown in FIG. 18C, the guide rails 150 may include
markers 151 at predetermined locations, i.e., known lengths from
the gasket member. The markers 151 may exit the upper ends 232 of
the tubular members 230 when the valve 14 is located immediately
adjacent the gasket member. This may provide the user confirmation
of the relative location and that the valve 14 may then be secured
to the gasket member.
[0150] For example, turning to FIGS. 20C-20E, when the valve 14 is
disposed immediately adjacent the gasket member, the retention
elements 154 on the guide rails 150 may encounter the detents 134
on the cantilever spring 132. As shown, the retention elements 154
may include tapered upper edges and the detents 134 may include
tapered lower edges. Thus, as the valve 14 is directed downwardly,
the tapered edges may slide relative to one another, causing the
cantilever spring 132 to deflect resiliently outward, as shown in
FIG. 20D. Once the detents 134 pass below the retention elements
154, the cantilever spring 132 may return inwardly, thereby
capturing the detents 134 below the locking tabs 154. The detents
134 may include substantially blunt upper edges and the retention
elements 154 may include substantially blunt lower edges, thereby
preventing the valve 14 from being moved subsequently away from the
gasket member, similar to the embodiment disclosed in the
references incorporated by reference above.
[0151] Turning to FIG. 20E, the guide rails 150 may include a
weakened region above the locking tabs 154 or may be otherwise
severable above the locking tabs 154. For example, the guide rails
150 may include one or more holes, thinned regions, and the like
(not shown), which may allow the guide rails 150 to preferential
break at the weakened regions, similar to other embodiments
described elsewhere herein.
[0152] With additional reference to FIGS. 18B and 18C, once the
markers 151 on the guide rails 150 appear from the upper ends 232
of the tubular members 230, the valve holder 210, and valve 14, may
be advanced further distally to secure the valve 14 to the gasket
member. As just described with reference to FIGS. 20A-20E, the
valve 14 may be advanced to engage the detents 134 with the
retention element 154. To facilitate this, the user may pull or
otherwise subject the guide rails 150 to proximal tension, while
advancing the valve holder 210 and valve 14 until a "click" or
other audible and/or tactile feedback is provided that confirms
that the detents 134 and retention elements 154 are engaged. Each
set of detents 134 and retention elements 154 may be engaged
sequentially or simultaneously.
[0153] Optionally, the valve holder tool may include one or more
safety features that prevent final engagement of the valve 14 with
the gasket member until the user makes an affirmative decision to
complete this step. For example, as shown in FIGS. 22A and 22B, the
valve holder tool 210' includes a handle 270' and cap 274' that may
facilitate manipulation of the valve holder tool 270' during a
procedure. The cap 274' may be disposed above a hub 272' coupled to
the shaft 212' such that the cap 274' may be movable towards the
hub 272' to complete deployment of the valve 14 (not shown).
However, features 276' on the cap 274' may be keyed with an opening
(not shown) through the hub 272' such that the user must rotate the
cap 274' to align the features 276' with the opening before the cap
274' may be directed towards the hub 272.' In addition, the shaft
213' may include an axial marker or other visual feature that may
be used to confirm the orientation of the head 220' and valve 14
relative to surrounding anatomy.
[0154] After securing the valve 14 to the gasket member, the guide
rails 150 may then be severed or otherwise separated from the
gasket member, e.g., above the retention elements 154, as shown in
FIG. 20E. Methods for breaking or otherwise severing the retention
elements 154 are described above. For example, in one embodiment,
each tubular member 230 may be rotated to twist the guide rail 150
received therein until the guide rail 150 breaks at the weakened
region. Alternatively, the hub 234 may be twisted to break the
guide rails 150, e.g., substantially simultaneously. In a further
alternative, shown in FIGS. 16A and 16B, the actuator 250 engaging
the ends of the guide rails 150 may be pulled proximally, thereby
breaking the guide rails 150 at their respective weakened regions.
In a further alternative, the guide rails 150 may be cut or
otherwise severed using a tool introduced into the biological
annulus.
[0155] Turning to FIG. 19A, the guide shields 156 may be removed
from the gasket member 112 before or after severing the guide rails
150. As shown, sutures 157 may be looped through individual
portions of the sewing cuff (not shown) and guide shields 156 that
may be cut or otherwise severed. The sutures 157 may then simply
unravel or otherwise loosen, allowing the guide shields 156 and
sutures 157 to be removed from the gasket member. Additional
information on methods for attaching and removing the guide shields
may be found in the references incorporated by reference above.
[0156] Turning to FIG. 19B, the valve 14 may be released from the
valve holder 210, e.g., before or after severing the guide rails
150 and/or removing the guide shields 156. As shown, sutures 13 may
be cut, thereby releasing the valve 14 from the head 220, and
allowing the head 220, valve holder 210, and sutures 13 to be
removed. FIGS. 19C and 19D show the valve holder 210 being
separated from the valve 14. As best seen in FIG. 19D, the severed
ends of the guide rails 150 may extend from the lower ends 233 of
the tubular members 232 when the valve holder 210 is removed,
thereby ensuring that the guide rails 150 are removed from the
patient. In addition or alternatively, the sutures 13 may be
anchored to a portion of the head 220 or valve holder 210, e.g.,
when the valve 14 is secured to the head 220. Thus, when the
sutures 13 are cut to allow the valve 14 to be separated from the
head 220, the sutures 13 may be remain anchored to the valve holder
210 to avoid having to retrieve individual pieces of the sutures
13.
[0157] FIGS. 21A-21D show various views of the implanted valve 14
and gasket member 12 with the leaflets of the valve 14 omitted for
clarity.
[0158] Turning to FIGS. 24A-26, another exemplary embodiment of a
valve member 314 is shown that generally includes an annular shaped
body or frame 332, a plurality of receptacles 380 attached to the
frame 332, and one or more valve elements (not shown for
simplicity). The valve member 14 may include a fabric covering
(also not shown) covering the frame 332, receptacles 380, and/or
other components of the valve member 14. The valve member 314 may
be included in any of the systems and methods described herein
and/or in the references incorporated by reference herein.
[0159] As shown in FIGS. 25A and 25B, the frame 332 is an annular
band including commissures 334, e.g., at the cusps, and spring tabs
370, e.g., at the lobes, similar to other embodiments described
herein. The spring tabs 370 may be supported by extensions of the
frame 332 defining windows 375, e.g., receiving the receptacles
380, as described further below. As shown, each spring tab 370
includes a lower end 370a substantially fixed relative to the frame
332 and a free upper end 370b, e.g., having a "T" shape. Thus, the
free end 370b of the spring tabs 370 may be deflectable radially
inwardly, but may be resiliently biased to return to the position
shown in FIGS. 25A and 25B.
[0160] Turning to FIGS. 24A and 24B, the receptacle 380 may be a
unitary body, e.g., injection molded, cast, machined, or otherwise
formed from plastic, metal, or composite material. Generally, the
receptacle 380 includes a main body 382 defining a substantially
smooth front surface 382a, as shown in FIG. 24A, and include a
plurality of lips or flanges 384, 385 extending from the main body
382. For example, a first set of flanges 384 may extend laterally
from the main body 382 but offset away from the front surface 382,
and a second set of flanges 385 may extend up and down from the
main body 382. Thus, the first set of flanges 384 may be offset
from the second set of flanges 385, e.g., for capturing a portion
of the frame 332 therebetween, as described further below.
[0161] The receptacle 380 includes a channel 386 along a back
surface of the main body 382 and a pair of locking tabs 388 within
the channel 386, as shown in FIG. 24B. The channel 386 may have
sufficient width to receive a guide rail 150 (see FIG. 26)
therethrough, e.g., between the tabs 388. The locking tabs 388 may
include ramped or tapered lower surfaces 388a and blunt upper
surfaces 388b. Optionally, as shown, raised ridges or lips 389 may
be provided that extends upwardly from the upper surfaces 388b,
thereby defining pocket behind the lips 389 and above the upper
surfaces 388b.
[0162] The receptacle 380 may include one or more additional
features formed therein, e.g., holes 383 for receiving sutures 390
or other fasteners therethrough.
[0163] Turning to FIGS. 25A and 25B, a receptacle 380 may be
attached to the frame 332 over each of the spring tabs 370, e.g.,
such that the receptacle 380 is disposed on an outer surface of the
frame 332. For example, the main body 382 of each receptacle 380
may be compressed to direct the first set of flanges 384 closer
together and the receptacle 380 may be inserted through the window
375 around one of the spring tabs 370. As the main body 382 is
inserted through the window 375, the second set of flanges 385 may
abut the outer surface of the frame 332 while the first set of
flanges 384 pass through behind the frame 332. The main body 382
may then be released, thereby capturing the frame 332 between the
first and second set of flanges 384, 385. Optionally, sutures 390
may be directed through holes 383 in the receptacles 380 and around
the portion of the frame 332 defining the windows 375, thereby
further securing the receptacles 380 to the frame 332.
[0164] The frame 332 may then be covered with fabric, e.g., over
the receptacles 380, using similar procedures for assembling valves
described elsewhere herein and in the references incorporated by
reference herein. Slits or other openings (not shown) may be formed
in the fabric covering above and below the receptacles 380, e.g.,
to provide access to the receptacles 380 during use.
[0165] With the receptacles 380 attached to the frame 332, the
channel 386 may be spaced apart from the frame 332, thereby
defining a vertical passage between the receptacles 380 and the
frame 332, similar to other embodiments described herein.
[0166] Turning to FIG. 26, during use, a guide rail 150 may be
passed through the passage, i.e., between the receptacle 380 and
frame 332, e.g., from below. The free of the guide rail 150 may
pass freely through the channel 386 of the receptacle 380, e.g.,
exiting out the top of the receptacle 380 and frame 332. As
retention elements 154 on the guide rails 150 enter the channel
386, the retention elements 154 may slide along the ramped lower
surfaces 388a of the locking tabs 388, thereby directing the spring
tab 370 away from the channel 386 to accommodate the retention
elements 154 passing over the locking tabs 388. Once the retention
elements 154 pass over the locking tabs 388, the spring tab 370 may
resiliently return inwardly, thereby directing the retention
elements 154 into the pockets defined by the lips 389 and upper
surfaces 388b of the locking tabs 388. Thus, if the guide rail 150
is pulled back down out of the receptacle 380, the blunt lower
edges of the retention elements 154 may engage the upper surfaces
388b, thereby preventing removal of the guide rail 150. The free
end of the guide rail 150 above the receptacle 380 may be severed,
similar to previous embodiments, e.g., including one or more
weakened regions (not shown) above the retention elements 154.
[0167] It will be appreciated that elements or components shown
with any embodiment herein are exemplary for the specific
embodiment and may be used on or in combination with other
embodiments disclosed herein.
[0168] While the invention is susceptible to various modifications,
and alternative forms, specific examples thereof have been shown in
the drawings and are herein described in detail. It should be
understood, however, that the invention is not to be limited to the
particular forms or methods disclosed, but to the contrary, the
invention is to cover all modifications, equivalents and
alternatives falling within the scope of the appended claims.
* * * * *