U.S. patent application number 11/532019 was filed with the patent office on 2007-01-11 for methods and apparatus for endovascularly replacing a heart valve.
Invention is credited to Claudio Argento, BrianD Brandt, Jean-Pierre Dueri, Ulrich R. Haug, Daniel Hildebrand, Dwight P. Morejohn, Amr Salahieh, Tom Saul, Hans F. Valencia.
Application Number | 20070010877 11/532019 |
Document ID | / |
Family ID | 37619216 |
Filed Date | 2007-01-11 |
United States Patent
Application |
20070010877 |
Kind Code |
A1 |
Salahieh; Amr ; et
al. |
January 11, 2007 |
Methods and Apparatus for Endovascularly Replacing a Heart
Valve
Abstract
The invention includes methods of and apparatus for
endovascularly replacing a heart valve of a patient. One aspect of
the invention provides a method including the steps of
endovascularly delivering a replacement valve and an expandable
anchor to a vicinity of the heart valve in an unexpanded
configuration; and applying an external non-hydraulically expanding
or non-pneumatically expanding actuation force on the anchor to
change the shape of the anchor, such as by applying proximally
and/or distally directed force on the anchor using a releasable
deployment tool to expand and contract the anchor or parts of the
anchor. Another aspect of the invention provides an apparatus
including a replacement valve; an anchor; and a deployment tool
comprising a plurality of anchor actuation elements adapted to
apply a non-hydraulically expanding or non-pneumatically expanding
actuation force on the anchor to reshape the anchor.
Inventors: |
Salahieh; Amr; (Saratoga,
CA) ; Dueri; Jean-Pierre; (Stockton, CA) ;
Valencia; Hans F.; (San Jose, CA) ; Hildebrand;
Daniel; (Menlo Park, CA) ; Brandt; BrianD;
(Santa Clara, CA) ; Morejohn; Dwight P.; (Davis,
CA) ; Argento; Claudio; (Los Gatos, CA) ;
Saul; Tom; (El Granada, CA) ; Haug; Ulrich R.;
(Campbell, CA) |
Correspondence
Address: |
WILSON SONSINI GOODRICH & ROSATI
650 PAGE MILL ROAD
PALO ALTO
CA
94304-1050
US
|
Family ID: |
37619216 |
Appl. No.: |
11/532019 |
Filed: |
September 14, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10982388 |
Nov 5, 2004 |
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|
11532019 |
Sep 14, 2006 |
|
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10746120 |
Dec 23, 2003 |
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10982388 |
Nov 5, 2004 |
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Current U.S.
Class: |
623/2.11 ;
623/1.26; 623/2.18 |
Current CPC
Class: |
A61F 2002/9528 20130101;
A61F 2/90 20130101; A61F 2220/005 20130101; A61F 2230/0078
20130101; A61F 2230/005 20130101; A61F 2250/006 20130101; A61F
2/2436 20130101; A61F 2220/0058 20130101; A61F 2220/0016 20130101;
A61F 2230/008 20130101; A61F 2/2433 20130101; A61F 2/2418 20130101;
A61F 2/2439 20130101; A61F 2/2409 20130101; A61F 2/2412 20130101;
A61F 2230/0054 20130101; A61F 2/243 20130101 |
Class at
Publication: |
623/002.11 ;
623/001.26; 623/002.18 |
International
Class: |
A61F 2/24 20060101
A61F002/24 |
Claims
1-93. (canceled)
94. A delivery device for a prosthetic heart valve, comprising: a
catheter body having a proximal end, a distal end, and defining a
longitudinal axis, the distal end of said catheter body comprising
a gripper having a plurality of elongated restraining members near
its distal end, wherein each restraining member extends generally
parallel to the longitudinal axis of the catheter and has a
proximal portion that is attached to the gripper and a distal
portion that is not attached to the gripper, thereby defining a
central region located internally of the plurality of restraining
members and a longitudinal slot between each adjacent pair of
restraining members.
95. The delivery device of claim 94, wherein said gripper comprises
three or more restraining members.
96. The delivery device of claim 94, further comprising a
prosthetic heart valve retained by the restraining members of said
gripper.
Description
CROSS REFERENCE
[0001] This application is a continuation of U.S. Ser. No.
10/982,388 filed Nov. 5, 2004, which is a continuation-in-part
application of U.S. Ser. No. 10/746,120, filed Dec. 23, 2003, the
disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] Heart valve surgery is used to repair or replace diseased
heart valves. Valve surgery is an open-heart procedure conducted
under general anesthesia. An incision is made through the patient's
sternum (sternotomy), and the patient's heart is stopped while
blood flow is rerouted through a heart-lung bypass machine.
[0003] Valve replacement may be indicated when there is a narrowing
of the native heart valve, commonly referred to as stenosis, or
when the native valve leaks or regurgitates. When replacing the
valve, the native valve is excised and replaced with either a
biologic or a mechanical valve. Mechanical valves require lifelong
anticoagulant medication to prevent blood clot formation, and
clicking of the valve often may be heard through the chest.
Biologic tissue valves typically do not require such medication.
Tissue valves may be obtained from cadavers or may be porcine or
bovine, and are commonly attached to synthetic rings that are
secured to the patient's heart.
[0004] Valve replacement surgery is a highly invasive operation
with significant concomitant risk. Risks include bleeding,
infection, stroke, heart attack, arrhythmia, renal failure, adverse
reactions to the anesthesia medications, as well as sudden death.
Two to five percent of patients die during surgery.
[0005] Post-surgery, patients temporarily may be confused due to
emboli and other factors associated with the heart-lung machine.
The first 2-3 days following surgery are spent in an intensive care
unit where heart functions can be closely monitored. The average
hospital stay is between 1 to 2 weeks, with several more weeks to
months required for complete recovery.
[0006] In recent years, advancements in minimally invasive surgery
and interventional cardiology have encouraged some investigators to
pursue percutaneous replacement of the aortic heart valve. See,
e.g., U.S. Pat. No. 6,168,614. In many of these procedures, the
replacement valve is deployed across the native diseased valve to
permanently hold the valve open, thereby alleviating a need to
excise the native valve and to position the replacement valve in
place of the native valve.
[0007] In the endovascular aortic valve replacement procedure,
accurate placement of aortic valves relative to coronary ostia and
the mitral valve is critical. Valve anchors comprising standard
self-expanding stent systems are expected to have very poor
accuracy in deployment, however. In a typical deployment procedure,
the proximal end of the stent is not released from the delivery
system until accurate placement is verified by fluoroscopy. The
stent may jump to another position once released, making it
impossible to know where the ends of the stent will be after
release with respect to the native valve, the coronary ostia and
the mitral valve.
[0008] Also, visualization of the way the new valve is functioning
prior to final deployment is very desirable. Due to the expected
jumping action of some self-expanding anchors, and because the
replacement valve may not be fully functional before final
deployment, visualization of valve function and position prior to
final and irreversible deployment may not be possible with these
systems.
[0009] Another expected drawback of prior art self-expanding
replacement heart valve systems is their relative lack of radial
strength. In order for self-expanding systems to be easily
delivered through a delivery sheath, the metal needs to flex and
bend inside the delivery catheter without being plastically
deformed. Expandable stent designs suitable for endovascular
delivery for other purposes may not have sufficient radial strength
to serve as replacement heart valve anchors. For example, there are
many commercial arterial stent systems that apply adequate radial
force against the artery wall to treat atherosclerosis and that can
collapse to a small enough of a diameter to fit inside a delivery
catheter without plastically deforming. However, when the stent has
a valve fastened inside it, and that valve must reside within the
heart, as is the case in aortic valve replacement, the anchoring of
the stent to vessel walls takes significantly more radial force,
especially during diastole. The force to hold back arterial
pressure and prevent blood from going back inside the ventricle
during diastole will be directly transferred to the stent/vessel
wall interface. Therefore, the amount of radial force required to
keep the self-expanding stent/valve in contact with the vessel wall
and not sliding will be much higher than in stents that do not have
valves inside of them. Moreover, a self-expanding stent without
sufficient radial force will end up dilating and contracting with
each heartbeat, thereby distorting the valve, affecting its
function and possibly causing it to migrate and dislodge
completely. Simply increasing strut thickness of the self-expanding
stent is not a good solution as it increases profile and/or a risk
of plastic deformation of the self-expanding stent.
[0010] In view of drawbacks associated with previously known
techniques for endovascularly replacing a heart valve, it would be
desirable to provide methods and apparatus that overcome those
drawbacks.
SUMMARY OF THE INVENTION
[0011] The invention includes methods of and apparatus for
endovascularly replacing a heart valve of a patient. One aspect of
the invention provides a method including the steps of
endovascularly delivering a replacement valve and an expandable
anchor to a vicinity of the heart valve in an unexpanded
configuration; and applying an external non-hydraulically expanding
or non-pneumatically expanding actuation force on the anchor
through a plurality of anchor actuation elements to change the
shape of the anchor, such as by applying a proximally and/or
distally directed force on the anchor through anchor actuation
elements to change the shape of the anchor. The anchor may be
locked in its expanded configuration.
[0012] Another aspect of the invention provides an apparatus for
endovascularly replacing a patient's heart valve, including: a
replacement valve; an anchor; and a deployment tool comprising a
plurality of anchor actuation elements adapted to apply a
non-hydraulically expanding or non-pneumatically expanding
actuation force on the anchor to reshape the anchor. An anchor lock
may be provided to lock the anchor in a deployed configuration, and
there may also be a lock prevention element actuatable from outside
the patient. Optionally, the anchor lock may be reversible.
[0013] Other aspects of the invention include methods and
apparatuses for endovascularly, percutaneously and/or
endoscopically delivering and deploying expandable devices in a
patient and optionally detaching a deployment tool from the
device.
INCORPORATION BY REFERENCE
[0014] All publications and patent applications mentioned in this
specification are herein incorporated by reference to the same
extent as if each individual publication or patent application was
specifically and individually indicated to be incorporated by
reference.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The novel features of the invention are set forth with
particularity in the appended claims. A better understanding of the
features and advantages of the present invention will be obtained
by reference to the following detailed description that sets forth
illustrative embodiments, in which the principles of the invention
are utilized, and the accompanying drawings of which:
[0016] FIGS. 1A and 1B show replacement valve apparatus in
accordance with the present invention. FIG. 1 illustrates the
apparatus in a collapsed delivery configuration within a delivery
system. FIG. 1B illustrates the apparatus in an expanded
configuration partially deployed from the delivery system.
[0017] FIGS. 2A-2F show an anchor of the apparatus of FIG. 1 in the
collapsed delivery configuration and the expanded deployed
configuration, as well as the full apparatus in the deployed
configuration, and optional locking mechanisms for use with the
apparatus.
[0018] FIGS. 3A-3E show the use of a replacement heart valve and
anchor to replace an aortic valve.
[0019] FIGS. 4A and 4B show an alternative anchor lock embodiment
in an unlocked configuration.
[0020] FIGS. 5A and 5B show the anchor lock of FIG. 4 in a locked
configuration.
[0021] FIG. 6 shows an alternative anchor deployment tool
attachment and release mechanism for use with the invention.
[0022] FIG. 7 shows the attachment and release mechanism of FIG. 6
in the process of being released.
[0023] FIG. 8 shows the attachment and release mechanism of FIGS. 6
and 7 in a released condition.
[0024] FIG. 9 shows an alternative embodiment of a replacement
heart valve and anchor and a deployment tool according to the
invention in an un-deployed configuration.
[0025] FIG. 10 shows the replacement heart valve and anchor of FIG.
9 in a partially deployed configuration.
[0026] FIG. 11 shows the replacement heart valve and anchor of
FIGS. 9 and 10 in a more fully deployed configuration but with the
deployment tool still attached.
[0027] FIG. 12 shows yet another embodiment of the delivery and
deployment apparatus of the invention in use with a replacement
heart valve and anchor.
[0028] FIG. 13 shows the delivery and deployment apparatus of FIG.
12 in the process of deploying a replacement heart valve and
anchor.
[0029] FIG. 14 shows a detail view of a variation of an anchor
post.
[0030] FIGS. 15A and 15B show an alternative variation of the post
having a lock alignment feature.
[0031] FIGS. 16A and 16B show a variation of the post having an
alternative lock alignment feature.
[0032] FIG. 17 shows a variation of the post having an expansile
element.
[0033] FIG. 18 shows a variation of the post with an alternative
expansile element.
[0034] FIGS. 19A-19C show a variation of the post having an
alternative lock alignment feature.
[0035] FIG. 20 shows the post variation of FIG. 14 in combination
with an illustrative actuator and release actuator.
[0036] FIGS. 21A-21C show a variation of the post, actuator and
release actuator that form an alternative releasable attachment
mechanism.
[0037] FIGS. 22A-22C show another variation of the releasable
attachment mechanism.
[0038] FIGS. 23A-23C show yet another variation of the releasable
attachment mechanism.
[0039] FIGS. 24A and 24B show still another variation of the
releasable attachment element.
[0040] FIG. 25 shows a variation of the post, actuator and anchor
lock element having a reversible lock.
[0041] FIGS. 26A-26C show a variation of the actuator, lock
actuator and release actuator.
[0042] FIG. 27 shows a variation of the anchor lock element having
a lock alignment feature.
[0043] FIGS. 28A and 28B show expansion, locking and actuation of
the releasable attachment mechanism of the apparatus of FIG.
27.
[0044] FIG. 29 shows another variation of the apparatus having an
actuable lock prevention mechanism.
[0045] FIGS. 30A and 30B show a variation of the post that is
configured to lock against the braid of the anchor.
[0046] FIGS. 31A-31C show actuation and release of a variation of
the anchor lock element.
[0047] FIGS. 32A and 32B show another variation of a releasable
actuation mechanism having a lock alignment mechanism which can be
cut from a tube.
[0048] FIGS. 33A-33D show actuation of a variation of the anchor
lock element that may be formed from a cut tube.
[0049] FIGS. 34A-34F show a variation of the post having an unlock
actuator.
[0050] FIGS. 35A and 35B show another buckle variation of the
anchor lock element.
[0051] FIG. 36 shows attachment of a variation of the anchor lock
element to the anchor.
[0052] FIG. 37 shows a variation of the post and anchor lock
element having a ratcheting lock.
[0053] FIGS. 38A and 38B show variations of the ratcheting
lock.
[0054] FIGS. 39A-39H show actuation of another variation of the
ratcheting lock.
[0055] FIGS. 40A-40C show a tubular variation of the ratcheting
lock element.
[0056] FIGS. 41A-41C show a variation of the anchor lock element of
FIG. 40.
[0057] FIGS. 42A and 42B show a variation of the apparatus of FIG.
41 comprising a lock alignment feature.
[0058] FIGS. 43A-43F show a method of actuating and adjusting the
ratcheting lock of the apparatus of FIG. 41.
[0059] FIGS. 44A and 44B show a variation of an
anchor/actuator.
[0060] FIGS. 45A-45C show detail views of the releasable attachment
mechanism of the actuator of FIG. 44.
[0061] FIGS. 46A-46C show a variation of the releasable attachment
mechanism of FIG. 45.
[0062] FIGS. 47A-47C show another variation of the releasable
attachment mechanism.
[0063] FIGS. 48A-48C show yet another variation of the releasable
attachment mechanism.
[0064] FIGS. 49A-49N show variations of a release actuator used in
conjunction with the releasable attachment mechanism of FIG.
45.
[0065] FIGS. 50A and 50B show detail views of an embodiment of the
delivery system/deployment tool.
[0066] FIGS. 51A and 51B show the delivery system/deployment tool
of FIG. 50 releasably attached to apparatus 10, and detached from
the apparatus.
[0067] FIGS. 52A and 52B show a variation of the delivery
system/deployment tool of FIGS. 50 and 51 wherein the actuators
extend from a unitary structure.
[0068] FIGS. 53A-53C show various ways to connect elements to the
anchor of the replacement valve apparatus.
DETAILED DESCRIPTION OF THE INVENTION
[0069] The present invention relates to apparatus and methods for
endovascularly delivering and deploying a prosthesis, e.g., an
aortic prosthesis, within and/or across a patient's native heart
valve, referred to hereinafter as replacing the patient's heart
valve. A delivery system and/or deployment tool is provided
including a sheath assembly and a guidewire for placing the
prosthetic apparatus endovascularly within the patient and a user
control allowing manipulation of the prosthetic apparatus from
external to the patient through the application of a
non-hydraulically expanding or non-pneumatically expanding force on
the anchor. A hydraulically or pneumatically expanding force would
be, for example, a force applied to the anchor by a balloon
expanded within the anchor. In certain embodiments, the application
of a non-hydraulically expanding or non-pneumatically expanding
force could include the use of a hydraulic component transmitting a
proximally or distally directed force on an anchor.
[0070] The apparatus includes an anchor and a replacement valve.
The anchor includes an expandable anchor such as a braid. In
preferred embodiments, the expandable braid includes closed edges,
but the edges may alternatively be open. The replacement valve is
adapted to be secured within the anchor, and as such, be delivered
endovascularly to the patient's heart to replace one of the
patient's native heart valves. More preferably, the apparatus and
methods of the present invention contemplate replacement of the
patient's aortic valve.
[0071] FIGS. 1A and 1B illustrate one embodiment of a delivery
system/deployment tool and apparatus in accordance with the present
invention. As seen in FIG. 1A, apparatus 10 may be collapsed for
delivery within delivery system/deployment tool 100. Delivery
system 100 includes guidewire G, nosecone 102, anchor actuation
elements 106, multi-lumen shaft or catheter 108 having optional
central lumen 109 and a plurality of circumferentially disposed
lumens Lu, external sheath 110 having optional proximal handle 111,
and control handle 120. Nosecone 102 may, for example, be
manipulated via a shaft extending through central lumen 109 of
multi-lumen catheter 108.
[0072] Anchor actuation elements 106 preferably comprise both
proximal anchor actuation elements and distal anchor actuation
elements. The proximal anchor actuation elements may, for example,
comprise actuators 106a that are releasably coupled to a proximal
region of anchor 30 of apparatus 10 via releasable attachment
mechanisms for manipulating a proximal region of apparatus 10. The
distal anchor actuation elements may comprise actuators 106b that
are releasably coupled to a distal region of anchor 30 via
releasable attachment mechanisms for manipulating the distal region
of apparatus 10. In some embodiments, the distal anchor actuation
elements may comprise posts or anchor attachment elements 32 of
anchor 30 and the releasable attachment mechanisms connecting
actuators 106b to posts 32. In an alternative configuration, the
proximal anchor actuation elements may be releasably coupled to a
proximal region of apparatus 10 through posts and releasable
attachment mechanisms for manipulation of a proximal region of the
apparatus, while the distal anchor actuation elements may connect
to a distal region of anchor 30 via releasable attachment
mechanisms to manipulate a distal region of the apparatus. As
another alternative, both proximal and distal anchor actuation
element may connect to anchor 30 via releasable attachment
mechanisms.
[0073] In the embodiment shown in FIG. 1, actuators 106a may, for
example, include stiff finger elements extending from a distal
region of multi-lumen shaft 108, while actuators 106b may include
control wires (e.g., stands of suture, or metal or polymer wires)
which pass through one or more lumens Lu of shaft 108. Release
actuators 112 for the releasable attachment mechanisms for both
sets of actuators also may pass through one or more lumens Lu of
shaft 108. The release actuators may comprise, for example, control
wires (e.g., strands of suture, or metal or polymer wires), covers,
mandrels, elongated elements, friction surfaces, wrap portions,
interference shapes, etc. The release actuators preferably are
movable relative to anchor actuation elements 106, e.g., via
control handle 120.
[0074] Control handle 120 is coupled to multi-lumen shaft 108. Knob
122 disposed in slot 123 may actuate release actuators 112 that
couple actuators 106a of anchor actuation elements 106 to apparatus
10. Likewise, knob 124 disposed in slot 125 may actuate release
actuators 112 that couple actuators 106b of anchor actuation
elements 106 to posts 32 of anchor 30 of apparatus 10. Handle 120
also comprises knob 126 for, e.g., manipulating the actuators 106b
to control movement of the distal region of apparatus 10 relative
to its proximal region. Conversely, controlled movement of the
proximal region of apparatus 10 relative to its distal region may
be achieved by holding knob 126 stationary while advancing or
retracting handle 120. Knob 126 optionally may move actuators 106b
in unison with their concomitant release actuators 112.
[0075] Apparatus 10 comprises anchor 30 and replacement valve 20.
Anchor 30 preferably comprises a braid. Such braid can have closed
ends at either or both its ends. Replacement valve 20 is preferably
coupled to the anchor along posts 32, e.g., along a valve
attachment structure, such as a tab and/or a plurality of holes.
Posts 32, therefore, may function as valve supports and may be
adapted to support the replacement valve within the anchor. In the
embodiment shown, there are three posts, corresponding to the
valve's three commissural attachment points. The posts can be
attached to the braid portion of anchor 30. The posts can be
attached to the braid's distal end, as shown in FIG. 2A, central
region, or proximal end. Replacement valve 20 can be composed of a
synthetic material and/or may be derived from animal tissue.
Replacement valve 20 is preferably configured to be secured within
anchor 30.
[0076] Anchor 30 comprises a plurality of anchor lock elements 34,
e.g., buckles .34, attached to its proximal region, one for each
post 32. Posts 32 may comprise a lock element that forms a two-part
locking mechanism with anchor lock elements 34 for maintaining
anchor 30 in a deployed or expanded configuration (e.g., as
illustrated in FIGS. 1B, 2B and 2C).
[0077] In this embodiment, anchor 30 is formed from a collapsible
and expandable wire braid. Anchor braid 30 is preferably
self-expanding and is preferably formed from a material such as
Nitinol, cobalt-chromium steel or stainless steel wire using one or
more strands of wire. Delivery and deployment of braided anchor 30
is similar to the delivery and deployment of the anchors described
in U.S. patent application Ser. No. 10/746,120. Specifically, in
one embodiment described below, during deployment braided anchor 30
is actively foreshortened by proximally retracting the actuators
106b relative to the actuators 106a to expand and lock the anchor
in place. In some embodiments, foreshortening may expand anchor 30
to a radially symmetrical, bilaterally symmetrical, or asymmetrical
expanded shape. The foreshortening step can include expanding a
first region of the anchor to a first diameter and a second region
of the anchor to a second diameter larger than the first diameter.
A third region may also be expanded to a diameter larger than the
first diameter. The expansion of various regions of the anchor
(e.g., the distal region) can be especially useful in locating the
aortic valve and centering the anchor within it. Preferably, the
secured anchor does not interfere with the mitral valve or the
ostia. In some embodiments, the anchor is allowed to self-expand
prior to the foreshortening step.
[0078] As seen in FIG. 1, after endovascular delivery through
sheath 110 to the vicinity of the patient's native valve (such as
the aortic valve), apparatus 10 may be expanded from the collapsed
delivery configuration of FIG. 1A to the expanded deployed
configuration of FIG. 1B using delivery system/deployment tool 100.
To deploy apparatus 10, external sheath 110 may be retracted
relative to apparatus 10 by proximally retracting sheath handle 111
relative to control handle 120. Sheath 10 is thereby removed from
the exterior of apparatus 10, permitting the anchor 30 to
self-expand. For example, if anchor braid 30 is composed of a shape
memory material, it may self-expand to or toward its "at-rest"
configuration. This at-rest configuration of the braid can be, for
example its expanded configuration, a collapsed configuration, or a
partially expanded configuration between the collapsed
configuration and the expanded configuration, or some combination.
In preferred embodiments, the anchor's at-rest configuration is
between the collapsed configuration and the expanded configuration.
Depending on the at-rest diameter of the braid and the diameter of
the patient's anatomy at the chosen deployment location, the anchor
may or may not self-expand to come into contact with the diameter
of the patient's anatomy at that location.
[0079] In its collapsed configuration, anchor 30 preferably has a
collapsed delivery diameter between about 3 to 30 Fr, or more
preferably 6 to 28 Fr, or more preferably 12 to 24 Fr. In some
embodiments, anchor 30 in its collapsed configuration will have a
length ranging from about 5 to about 170 mm, more preferably from
about 10 to about 160 mm, more preferably from about 15 to about
150 mm, more preferably from about 20 to about 140 mm, or more
preferably from about 25 mm to about 130 mm.
[0080] Similarly, in its expanded configuration, anchor 30
preferable has a diameter ranging between about 10 to about 36 mm,
or more preferably from about 24 to about 33 mm, or more preferably
from about 24 to about 30 mm. In some embodiments, anchor 30 in its
expanded configuration will have a length ranging from about 1 to
about 50 mm, more preferably from about 2 to about 40 mm, more
preferably from about 5 to about 30 mm, or more preferably from
about 7 to about 20 mm.
[0081] Overall, the ratio of deployed to collapsed/sheathed lengths
is preferably between about 0.05 and 0.5, more preferably about 0.1
to 0.35, or more preferably about 0.15 to 0.25. In any of the
embodiments herein, anchor 30 in its expanded configuration
preferably has a radial crush strength that maintains the anchor
substantially un-deformed in response to a pressure of up to about
0.5 atm directed substantially radially inward toward the central
axis, or more preferably up to about 2 atm directed substantially
radially inward toward the central axis. In addition, in any of the
embodiments herein, the anchor preferably has an axial spring
constant of between about 10 to 250 g/cm, more preferably between
about 20 to 200 g/cm, or more preferably between about 40 to 160
g/cm. In addition, in any of the embodiments herein, the anchor is
preferably adapted to support the replacement valve at the anchor
site in response to a differential pressure of up to about 120 mm
Hg, more preferably up to about 240 mm Hg, or more preferably up to
about 320 mm Hg.
[0082] These parameters are not intended to be limiting. Additional
parameters within the scope of the present invention will be
apparent to those of skill in the art.
[0083] As seen in FIG. 1B, anchor 30 may be expanded to a fully
deployed configuration from a partial deployed configuration (e.g.,
self-expanded configuration) by actively foreshortening anchor 30
during endovascular deployment. In some embodiments, foreshortening
of the apparatus involves applying a distally directed force on the
proximal end of the anchor by one or more anchor actuation elements
to move the proximal end of the anchor distally while maintaining
the position of the distal end of the anchor. For example, the
proximal region of anchor 30 may be pushed distally by certain
anchor actuation elements 106, e.g., actuators 106a. Alternatively,
foreshortening of the apparatus involves applying a proximally
directed force on the distal end of the anchor by one or more
anchor actuation elements to move the distal end of the anchor
proximally while maintaining the position of the proximal end of
the anchor. For example, the distal region of anchor 30 may be
pulled proximally via a proximally directed force applied by post
actuation elements 106b, this force opposed by anchor actuators
106a.
[0084] Anchor actuation elements 106 preferably are adapted to
expand radially as the anchor expands radially and to contract
radially as the anchor contracts radially. Furthermore, proximally
or distally directed forces by the anchor actuation elements on one
end of the anchor do not diametrically constrain the opposite end
of the anchor. In addition, when a proximally or distally directed
force is applied on the anchor by the anchor actuation elements, it
is preferably applied without passing any portion of a deployment
system through a center opening of the replacement valve. This
arrangement enables the replacement valve to operate during
deployment and before removal of the deployment system.
[0085] The distal anchor actuation elements may include, for
example, actuators 106b and/or release actuators 112 that are
controlled, e.g., by control knobs 124 and 126 of control handle
120. Similarly, the proximal regions of anchor 30 may be pushed
distally via proximal anchor actuation elements, e.g., actuators
106a, at the proximal region of the anchor. The proximal anchor
actuation elements facilitate application of a distally directed
force to the proximal end of anchor 30 to move or constrain the
proximal end of the anchor distally and are controlled through
motion of shaft 108 relative to the distal anchor actuation
elements. Control knob 122 of control handle 120 may control
release actuators 112 for releasing the proximal anchor actuation
elements from the braid. The proximal anchor actuation elements may
be further adapted to expand as the proximal end of the anchor
expands radially during application of a distally directed force on
the proximal end of the anchor. Preferably, the proximal anchor
actuation elements apply a distally directed force on the proximal
end of the anchor system through a plurality of actuators 106a in
order to expand the braid of anchor 30. Such braid expansion
optionally may be assisted via inflation of a balloon catheter (see
FIGS. 12 and 13) reversibly disposed within apparatus 10, as
described in U.S. patent application Ser. No. 10/746,120.
[0086] In the fully deployed configuration, lock elements of posts
32 and anchor lock elements or buckles 34 of anchor 30 may be used
to lock and maintain the anchor in the deployed configuration.
Apparatus 10 may be repositioned or retrieved from the patient
until the lock elements of posts 32 have been interlocked with
anchor lock elements 34 of anchor 30 to form lock 40. In one
embodiment, actuators 106b and attendant release actuators 112
comprise control wires attached to posts 32 that are threaded
through buckles 34 so that the proximally directed force exerted on
posts 32 by the control wires during deployment pulls a lock
element of posts 32 toward and through buckles 34 to form lock 40.
In this manner, the control wires may act as both anchor actuators
and lock actuators.
[0087] Such lock optionally may be selectively reversible to allow
for repositioning and/or retrieval of apparatus 10 during or
post-deployment. When the lock is selectively reversible, the
apparatus may be repositioned and/or retrieved as desired, i.e.,
even after actuation of lock 40.
[0088] Locks used herein may also include a plurality of levels of
locking wherein each level of locking results in a different amount
of expansion. For example, the anchor lock elements at the proximal
end of the post can have multiple configurations for locking within
the buckle wherein each configuration results in a different amount
of anchor expansion (see, e.g., FIG. 2F). Such locking mechanisms
may, for example, comprise ratchets having multiple lock locations.
Furthermore, lock alignment features may be provided to facilitate
alignment of the post and anchor lock elements, such as a hinge or
an oversized width of the post or anchor lock elements.
Furtherstill, lock prevention mechanisms may be provided to
preclude locking until desired by a medical practitioner.
[0089] When apparatus 10 is placed across a patient's diseased
heart valve, anchor 30 may be used to displace the patient's native
valve leaflets, and replacement valve 20 will thereafter serve in
place of the native valve. After final positioning and expansion,
apparatus 10 may be decoupled from delivery system 100 by
decoupling the proximal and distal anchor actuation elements 106
from the apparatus via releasable attachment mechanisms, e.g., by
decoupling proximal actuators 106a from braided anchor 30 and
distal actuators 106b from posts 32 of the anchor via the
releasable attachment mechanisms. Moving release actuators 112,
e.g., using knobs 122 and 124 of handle 120, may, for example,
actuate the releasable attachment mechanisms. Preferably, the
releasable attachment mechanisms may be actuated by moving the
release actuator(s) less than about 1 inch. After decoupling,
delivery system/deployment tool 100 may be removed from the
patient, thereby completing endovascular replacement of a patient's
heart valve.
[0090] Prior to implantation of replacement valve apparatus
described herein, it may be desirable to perform a valvuloplasty on
the patient's diseased valve by inserting a balloon into the valve
and expanding it using, e.g., saline mixed with a contrast agent.
In addition to preparing the valve site for implant, fluoroscopic
viewing of the valvuloplasty will help determine the appropriate
size of replacement valve implant to use.
[0091] FIGS. 2A-2C show further details of anchor 30 of apparatus
10. FIG. 2A shows the apparatus in a collapsed configuration, such
as for delivery within a sheath or other lumen or for retrieval and
recapture into a sheath or other lumen. FIGS. 2B and 2C show the
anchor and valve in an expanded and locked configuration.
[0092] As shown in FIG. 2B, anchor 30 illustratively has three
posts and three buckles. As seen in FIG. 2C, the three leaflets of
replacement valve 20 may be coupled to the three posts 32 along
valve support structures. Thus, posts 32 act as valve supports. The
posts, unlike the braid, do not collapse or expand. In some
embodiments, a post 32 has one or more proximal slots 33, at least
one proximal hole 36a and at least one distal hole 36b. Leaflet
tissue may, for example, be passed through slot 33 and sutured in
place via suture routed through one or more proximal holes 36a. In
this manner, slot(s) 33 and hole(s) 36a may form a valve support
structure. Alternative valve support structures known in the art
for fixing valve leaflets to posts may also be employed.
[0093] Posts 32 may be coupled to anchor braid 30 via one or more
distal holes 36b. For example, anchor braid 30 may be woven through
holes 36b, or a suture or wire may be routed through holes 36b and
tied to the braid. Yet another proximal hole (not shown) in post 32
serves as an anchor lock element that interfaces with the anchor
lock element provided by buckle 34 to form lock 40. Buckles 34 may
likewise be attached to anchor braid 30 via weaving or
suturing.
[0094] Alternative locks may be used to lock the anchor of the
present invention in the foreshortened configuration, as shown,
e.g., in FIGS. 2D-2F. Preferably, a lock of the present invention
can have multiple locking options such that locking can confer a
plurality of amounts of expansion. Furthermore, the locking option
can be employed asymmetrically to confer non-cylindrical shapes to
the anchor. In FIG. 2D, lock 40' comprises male lock element 44
disposed on post 32 and anchor lock element 34 disposed on braided
anchor 30. Anchor lock element 34 illustratively comprises
triangular protrusion or eyelet 42 of anchor 30. The triangular
shape of female lock element 42 may facilitate mating of male lock
element 44 with the female lock element without necessitating
deformation of the male lock element. One or more holes 45 may be
provided through post 32, e.g., for releasably attaching an
actuator 106b to the post.
[0095] In FIG. 2E, lock 40'' comprises alternative male lock
element 44' having multiple in-line arrowheads 46 along posts 32.
Each arrowhead comprises resiliently deformable appendages 48 to
facilitate passage through female lock element 42', which
illustratively comprises a rounded eyelet. Appendages 48 optionally
comprise holes 49, such that releasable lock prevention mechanism
47, illustratively a control wire, may pass through the holes to
constrain the appendages in the deformed configuration. To actuate
lock 40'', one or more arrowheads 46 of male lock element 44' are
drawn through female lock element 42', e.g., via a post/lock
actuator, and the lock prevention mechanism is removed from holes
49, thereby causing appendages 48 to resiliently expand and actuate
lock 40''.
[0096] Advantageously, providing multiple arrowheads 46 along posts
32 yields a ratchet that facilitates in-vivo determination of a
degree of foreshortening and expansion imposed upon anchor 30.
Furthermore, optionally constraining appendages 48 of arrowheads 46
via mechanism 47 prevents actuation of lock 40'' (and thereby
deployment of apparatus 10) even after male element 44' has been
advanced through female element 42'. Only after a medical
practitioner has removed lock prevention mechanism 47, which
constrains appendages 48, is lock 40'' fully engaged and is
deployment no longer reversible.
[0097] Lock 40''' of FIG. 2F is similar to lock 40'' of FIG. 2E,
except that holes 49 on appendages 48 have been eliminated, and the
lock prevention mechanism comprises overtube or cover 47. Overtube
47 constrains appendages 48 to prevent locking until a medical
practitioner has determined that apparatus of the present invention
has been foreshortened and positioned adequately at a treatment
site. Lock 40''' may, for example, be actuated by applying a
proximally-directed force to actuator 106b. Actuator 106b
illustratively comprises a control wire releasably disposed through
hole 45 in post 32. Lock prevention mechanism 47 then is withdrawn
proximally relative to anchor 30, which causes the appendages to
resiliently expand, thereby fully actuating lock 40'''.
[0098] Referring now to FIG. 3 in conjunction with FIGS. 1 and 2, a
method of endovascularly replacing a patient's diseased aortic
valve with apparatus 10 and delivery system/deployment tool 100 is
described. As seen in FIG. 3A, sheath 110 of delivery system 100,
having apparatus 10 disposed therein, is endovascularly advanced
over guidewire G, preferably in a retrograde fashion (although an
antegrade or hybrid approach alternatively may be used), through a
patient's aorta A to the patient's diseased aortic valve AV.
Nosecone 102 precedes sheath 110 in a known manner. In FIG. 3B,
sheath 110 is positioned such that its distal region is disposed
within left ventricle LV of the patient's heart H.
[0099] Apparatus 10 is deployed from lumen Lu of sheath 110, for
example, under fluoroscopic guidance by proximally retracting
proximal handle 111 of sheath 110 relative to shaft 108, such that
anchor 30 of apparatus 10 dynamically self-expands to the partially
deployed configuration of FIG. 3C. Advantageously, apparatus 10 may
be retracted within lumen Lu of sheath 110 by retracting shaft 108
relative to the sheath, and thereby retracting actuators 106a
coupled to anchor 30 relative to sheath 110. In this manner, anchor
30 may be retrieved even after the anchor has dynamically expanded
to the partially deployed configuration, for example, to abort the
procedure or to reposition apparatus 10 or delivery system 100. As
yet another advantage, apparatus 10 may be dynamically
repositioned, in order to properly align the apparatus relative to
anatomical landmarks, such as the patient's coronary ostia or the
patient's native valve leaflets L. When properly aligned, a distal
region of anchor 30 preferably is disposed distal of the leaflets,
while a central region of the anchor is disposed across the
leaflets and a proximal region is disposed proximal of the
leaflets.
[0100] Once properly aligned, actuators 106b are proximally
retracted relative to actuators 106a, e.g., via knob 126 of handle
120, to impose foreshortening upon anchor 30 and further expand
apparatus 10 to the fully deployed configuration, as in FIG. 3D.
Foreshortening increases the radial strength of anchor 30 to ensure
prolonged patency of valve annulus An, as well as to provide a
better seal for apparatus 10 that reduces paravalvular
regurgitation. Lock 40 formed by engaging post lock elements 44 of
posts 32 with anchor lock elements 34 of anchor 30 maintains
imposed foreshortening. Replacement valve 20 is properly seated
within anchor 30, and normal blood flow between left ventricle LV
and aorta A is thereafter completely regulated by apparatus 10,
although valve 20 is functional during deployment as well.
Deployment of apparatus 10 advantageously is fully reversible until
the locks have been actuated. Releasable lock prevention mechanisms
may be provided to ensure that the locks are not actuated
prematurely. Furthermore, the locks may be reversible, such that
apparatus 10 may be retrieved or repositioned even after actuation
of the locks.
[0101] Once apparatus 10 is fully expanded and locked in the
expanded configuration, actuators 106a are decoupled from anchor 30
by actuating releasable attachment mechanisms, e.g., by retracting
release actuators 112 relative to the actuators 106a via knob 122
of handle 120. Likewise, actuators 106b are decoupled from posts 32
by actuating releasable attachment mechanisms, e.g., by retracting
release actuators 112 relative to the actuators 106b via knob 124
of handle 120. As seen in FIG. 3E, delivery system 100 then may be
removed from the patient, thereby completing deployment of
apparatus 10. Optional barb elements 37 engage the patient's native
valve leaflets, e.g. to preclude migration of the apparatus and/or
to reduce paravalvular regurgitation.
[0102] FIGS. 4 and 5 illustrate anchor lock mechanisms depicted in
FIG. 4 in the locked configuration. FIGS. 4 and 5 should be viewed
as if cylindrical anchor 30 has been cut open and laid flat. Posts
32 coupled to anchor 30 illustratively comprise actuator attachment
elements 200 and lock elements 202, e.g., eyelets or holes formed
through the posts. Anchor 30 comprises anchor lock elements 34,
illustratively buckles, which are configured to mate with lock
elements 202 of the posts. Posts 32 and buckles 34 may, for
example, be connected to braided anchor 30 by inter-weaving the
posts and the buckles into the braid of the anchor. Alternatively,
the posts and/or buckles may be sutured, soldered, welded,
connected with adhesive, etc., to the anchor. The commissures of
previously described replacement valve 20 may be connected to posts
32 along all or a portion of their lengths.
[0103] Lock elements 202 of posts 32 mate with tabs 210 extending
into holes 212 in anchor lock elements 34. To lock, actuators 106b,
which releasably pass through actuator attachment elements 200 of
posts 32 and holes 212 of anchor lock elements 34, are pulled
proximally by anchor actuators 106b (illustratively control wires)
with respect to the proximal end of braided anchor 30 to draw posts
32 through holes 212 so that tabs 210 engage lock elements 202 of
posts 32. Also shown are unlocking actuators 220, illustratively
control wires, which pass through anchor lock eyelets 214 in anchor
lock elements 34. If needed, during the procedure, the user may
pull on unlocking actuators 220, thereby reversing orientation of
tabs 210, releasing the anchor and allowing for repositioning of
the device or its removal from the patient. Only when final
positioning as desired by the operating physician is achieved,
would unlocking actuators 220, as well as actuators 106b, be
removed from apparatus 10 and the patient.
[0104] Referring now to FIGS. 6-8, an alternative way of releasing
the connection between the anchor (or post, etc.) and the anchor
actuation elements is described. In FIG. 6, release actuator 112,
illustratively a control wire, extends through actuator 106a from
outside the patient, loops through the proximal region of braided
anchor 30 and extends partially back into actuator 106a. The
doubled up portion of release actuator 112 creates a force fit
within actuator 106a that maintains the release actuator's position
with respect to the actuator 106a when all release actuators 112
within actuators 106a are pulled proximally, e.g., when applying a
proximally directed force on anchor 30. When a single release
actuator 112 is pulled proximally, however, the frictional fit
between that release actuator and the actuator 106a in which it is
disposed is overcome, enabling the end 113 of release actuator 112
to pull free of actuator 106a, as shown in FIGS. 7 and 8, thereby
releasing anchor 30. In an alternative embodiment, the doubled up
portion of release actuator 112 may extend proximally to, e.g.,
control handle 120. In such an embodiment, expansion of anchor 30
may be achieved by proximally retracting both ends of the doubled
up release actuator 112 via the control handle, while release of
actuator 106a may be achieved by pulling on one end of release
actuator 112.
[0105] FIGS. 9-11 show additional views of apparatus 10. Anchor 30
is made of a metal braid, such as Nitinol or stainless steel.
Replacement valve 20 is disposed within anchor 30. Anchor 30 is
actuated in substantially the same way as described previously
through the application of proximally and distally directed forces
from distal anchor actuators (not shown) and actuators 106a.
[0106] FIGS. 12 and 13 show another embodiment of the delivery and
deployment apparatus of the invention. In this embodiment, the
nosecone (e.g., element 102 of FIGS. 1A and 3) is replaced by
angioplasty balloon catheter 230. Thus, angioplasty balloon
catheter 230 precedes sheath 110 on guidewire G. When anchor 30 and
valve 20 are expanded through the operation of anchor actuation
elements 106 as described above, balloon catheter 230 is retracted
proximally within the expanded anchor and valve and may be inflated
to further expand the apparatus 10, as desired. Optionally, a
separate balloon catheter or valvuloplasty catheter may be advanced
within apparatus 10 after expansion thereof to achieve additional
expansion of the apparatus.
[0107] Referring now to FIG. 14, a detail view of a variation of
post 32 is described. In FIG. 14, post 32 illustratively comprises
actuator attachment element 250 for attaching the post to an
actuator 106b; post lock element 252, illustratively a slot, for
interlocking post 32 with an anchor lock element 34; valve
attachment structure 254, comprising slot 255 and a plurality of
holes 256, for attaching replacement valve 20 to the post (a tab of
the valve may be passed through slot 255, then sewn to the back of
the post through holes 256); and braid attachment element 258 for
attaching the post to a distal region of anchor 30. The braid of
anchor 30 may, for example, be interwoven through braid attachment
element 258. Post 32 may be fabricated from a variety of materials,
e.g., metallic materials such as stainless steel, and may be laser
cut, die cast, etc. In this variation of post 32, valve 20 is
disposed distal of lock element 252. In alternative variations, the
valve may be attached to the post proximal of the lock element or
in-line with the lock element (i.e., neither proximal nor distal to
the lock).
[0108] FIG. 15 provide an alternative variation of post 32. In FIG.
15, post 32 comprises lock element 260 having lock alignment
feature 262, illustratively hinge 263. Hinge 263 allows lock
element 260 to rotate from a position in line with post 32, as in
FIG. 15A, to a position out of alignment with the post, as in FIG.
15B, thereby facilitating alignment with an anchor lock element 34.
As shown, post 32 further comprises actuator attachment element
264, illustratively an eyelet, valve support structure 266 having
slot 267 and a plurality of holes 268, and braid attachment element
269.
[0109] FIG. 16 illustrate an alternative variation of lock
alignment feature 262 comprising spring 270. As with hinge 263,
spring 270 facilitates alignment of post lock element 260 with an
anchor lock element 34 by allowing the post lock element to rotate
from a position in line with post 32, as in FIG. 16A, to a position
out of alignment with the post, as in FIG. 16B. Spring 270 also
applies a restoring force that urges post lock element 260 back
into alignment with post 32. Furthermore, spring 270 may facilitate
dynamic elongation of post 32 in response to axial tension. This
elongation may facilitate axial lengthening of anchor 30 in
response to radially inward compression applied to the anchor.
[0110] With reference to FIG. 17, another variation of post 32 is
provided comprising expansion zone 280, which may, for example,
comprise a laser cut feature along post 32. Expansion zone 280
facilitates dynamic elongation of post 32 in response to axial
tension applied to the post, which facilitates axial lengthening of
anchor 30 in response to radially inward compression applied to the
anchor. FIG. 18 illustrates an alternative expansile element 290
comprising a curved wire or rod that may be elongated and
straightened through application of axial tension to facilitate
axial lengthening of the anchor in response to radially inward
compression applied to the anchor (and thereby axial tension
applied to post 32 via interaction between post lock element 260
and an anchor lock element 34).
[0111] Element 290 additionally or alternatively may serve as a
lock alignment feature. In such a configuration, element 290
optionally may not be expansile. More generally, post 32 may
comprise proximal and distal ends connected by a tensile
member.
[0112] FIG. 19 illustrate another variation of post 32 having
another alternative lock alignment feature 262. In FIG. 19,
actuator 106b applies a proximally-directed force which brings post
lock element 260 and anchor lock element 34 proximate to one
another allowing the system to lock. Anchor lock element 34 defines
a lock width W.sub.1. In this embodiment, lock alignment feature
262 comprises post lock element lock area or width W.sub.2 that is
substantially wider than the lock width W.sub.1, for example, at
least about twice as wide. This increased width enhances the
probability of interlocking the post and anchor lock elements, even
at sharply misaligned angles. In FIG. 19, post 32 and anchor lock
element 34 are disposed at an illustrative misalignment angle of
about 10.degree..
[0113] Referring now to FIG. 20, the variation of post 32 of FIG.
14 is shown in combination with an illustrative actuator 106b and
release actuator 112. In FIG. 20, actuator 106b illustratively
comprises rod 300 having post attachment element 302 that mates
with actuator attachment element 250 of post 32. Angled camming
surfaces 304 and 305 of post attachment element 302 and actuator
attachment element 250, respectively, form an interface between
post attachment element 302 and actuator attachment element 250.
Proximal movement of actuator 106b with respect to post 32 is
translated by the camming surfaces into a lateral force between the
two elements that acts to separate and release post 32 from
actuator 106b. Release actuator 112, illustratively tube 310, may
be advanced over actuator 300 to cover the camming surface
interface of the post and the actuator 106b, thereby forming a
releasable attachment mechanism for securing the post to the
actuator even during application of axial tension to the actuator.
To separate post 32 from actuator 106b, e.g., after expansion and
locking of anchor 30, release actuator 112 may be retracted
relative to actuator 106b to the position shown in FIG. 20, thereby
removing a constraint from camming surfaces 304 and 305 and
allowing the post and actuator to be pulled apart. Release actuator
112 preferably is retracted less than about 1 inch relative to the
actuator 106b in order to actuate the releasable attachment
mechanism, e.g., to remove constraint from camming surfaces 304 and
305.
[0114] Referring now to FIG. 21, an alternative releasable
attachment mechanism for attaching a variation of post 32 to a
variation of actuator 106b is described. In FIGS. 21A and 21B, post
32 having actuator attachment element 320, illustratively an
enlarged proximal opening within the post, is interference fit with
post attachment element 330 of actuator 106b, illustratively an
enlarged bulb, knob or other distal protrusion of the actuator. The
slope of element 330 provides a camming surface that interfaces
with an inside surface of opening 320. The angle of the camming
interface between element 330 and opening 320 translates proximal
movement of actuator 106b with respect to post 32 into a lateral
movement between actuator 106b and post 32, thereby separating
these elements. Release actuator 112, illustratively tube 310,
covers the interference fit releasable attachment mechanism to
preclude lateral movement of the post attachment element relative
to the actuator attachment element, thereby releasably attaching
the post to the actuator 106b. In FIG. 21C, tube 310 is retracted
relative to the post and actuator, which permits lateral movement
between the post and actuator attachment elements, thereby
separating actuator 106b from post 32. If tube 310 has not been
retracted, of course, proximal movement of actuator 106b moves post
32 and the distal portion of the anchor proximally.
[0115] FIG. 22 illustrate a variation of the releasable attachment
mechanism of FIG. 21. In the variation of FIG. 22, actuator
attachment element 320 of post 32 is deformable from a
substantially round profile to an oval or "figure eight" profile by
advancement of release actuator 112 over the attachment element.
This forms a releasable attachment mechanism. In the deformed
profile of FIGS. 22A and 22B, post attachment element 330 of
actuator 106b is interference fit with the deformed actuator
attachment element of post 32. In FIG. 22C, retraction of release
actuator 112 relative to the post and actuator allows actuator
attachment element 320 to resiliently resume its un-deformed or
at-rest configuration, thereby permitting separation of post 32
from actuator 106b. Actuator attachment element 320 may, for
example, be fabricated from a shape memory material, such as
Nitinol. A camming surface 331 on post attachment element 330 and a
corresponding surface on the inner portion of element 320 translate
proximal movement of actuator 106b with respect to post 32 into
lateral movement of element 330 with respect to element 320 when
release actuator 112 has been retracted.
[0116] In the variation of FIG. 23, post attachment element 330 is
deformable (as in FIGS. 23A and 23B), and anchor attachment element
320 may be interference fit with the post attachment element. FIG.
23C shows the post attachment element 330 in its at-rest
configuration after tube 310 has been retracted, thereby releasing
anchor attachment element 320. As will be apparent, for many or all
of the two-part locking or attachment element elements described
herein, the position of the elements may be reversed.
[0117] In FIG. 24, post attachment element 330 comprises wrap
portion 332 that may be inserted through anchor attachment element
320, illustratively an eyelet, wrapped backwards, then covered with
release actuator tube 310 to constrain the wrap portion 332 in the
wrapped configuration, as in FIG. 24A. Release actuator tube 310
may be retracted relative to the wrap portion to resiliently or
dynamically (e.g., by retracting actuator 106b relative to post 32)
reshape the wrap portion to a substantially straight configuration
for releasing the attachment between the post and the actuator, as
in FIG. 24B. Wrap portion 332 preferably is fabricated from a shape
memory material, such as Nitinol, or a resilient material, such as
spring steel.
[0118] FIG. 25 shows another variation of the post, actuator and
anchor lock element. In FIG. 25, post 32 comprises post lock
element 260 and actuator attachment element 264, illustratively an
eyelet, through which actuator 106b is reversibly disposed. Anchor
lock element 34 illustratively comprises a buckle, which may, for
example, be formed from a cut tube or a bent resilient material.
Anchor lock element 34 comprises anchor or braid attachment element
340 for attaching the buckle to anchor 30, and tab 342 for
interlocking the buckle with post lock element 260, which
illustratively is a slot formed through post 32. Actuator 106b
therefore actuates the post (and therefore the distal end of the
anchor to which the post is attached) as well as the anchor lock.
Actuator 106b may be released from the post (and therefore from the
anchor) by pulling one end of the control wire proximally to draw
the control wire through and out of opening 264.
[0119] Anchor lock element 34 also comprises optional unlock
actuator attachment 344, illustratively a pair of eyelets, through
which unlock actuator 350 is releasably coupled to anchor lock
element 34. Unlock actuator 350 illustratively comprises a control
wire. Upon locking of tab 342 of buckle 34 within slot 260 of post
32, a proximally-directed force applied to unlock actuator 350 may
remove the tab from the slot, thereby unlocking buckle 34 and post
32 and permitting the anchor to contract and elongate. Unlocking
may be utilized, for example, to reposition or retrieve the anchor
and valve apparatus even after the apparatus has been locked in the
fully deployed configuration, as described previously with respect
to FIG. 3.
[0120] FIG. 26 show another variation of the actuator, the lock
actuator and the release actuator. As with other anchor lock
elements, anchor lock element 34 in this embodiment is attached to
a proximal end of the anchor, and the distal end of post 32 is
attached to a distal end of the anchor. The anchor is not shown in
FIG. 26 for ease of illustration. For the purposes of illustration,
the unlock actuator also is not shown in FIG. 26.
[0121] As shown, actuator 106b actuates both post 32 (and therefore
the distal end of the anchor to which the post is attached) and the
lock formed between post lock element 260 and anchor lock element
34. In FIG. 26A, release actuator 112 passes through actuator 106b
to actuate the releasable attachment mechanism between post 32 and
actuator 106b. FIG. 26B provides a detail view of the releasable
attachment mechanism. Actuator 106b comprises wrap portion 360 that
passes through actuator attachment element 264 and wraps around the
end of post 32. Wrap portion 360 may comprise a shape memory
material, such as Nitinol, or a deformable material, e.g., a
resiliently deformable material.
[0122] Wrap portion 360 further comprises first opening 362 for
engaging release actuator 112, illustratively a wire or rod that
passes through lumen Lu of actuator 106b. The walls of the lumen
act a linear bearing and/or motion guide during advancement and
retraction of the release actuator relative to the actuator.
Actuator 106b also comprises second opening 364, which may be
aligned with first opening 362 to engage release actuator 112, as
shown. As seen in the cross-sectional view of FIG. 26C, wrap
portion 360, and especially the curved portion 361 of the wrap
portion, acts as a spring element that urges the first opening out
of alignment with the second opening. In this manner, release
actuator 112 may be interference or friction fit through first
opening 362 and second opening 364. Retraction of the release
actuator proximal of the first and second openings may actuate the
releasable attachment mechanism to resiliently or dynamically
unwrap portion 360 and release actuator 106b from post 32. Wrap
and/or curved portion 360/361 of actuator 106b illustratively is
disposed at a distal end of the actuator.
[0123] As will be apparent to those of skill in the art, the
releasable attachment mechanism of FIG. 26 may also be utilized to
attach a actuator 106a to a braided anchor 30. More generally, wrap
portion 360 provides an illustrative first shape on an anchor
actuation element 106 that is adapted to mate with a second shape
on a post or anchor actuator attachment element (such as element
264 in FIG. 26, or a wire of the braid of anchor 30) to
substantially prevent relative distal or proximal movement between
the anchor actuation element and the anchor. The apparatus further
comprises a release actuator adapted to actuate the releasable
attachment mechanism. The release actuator is adapted to be moved
to permit relative movement between the first shape and the second
shape. This relative movement may change the first shape and/or the
second shape to a third shape that permits relative distal or
proximal movement between the anchor actuation element and the
anchor or post. Furthermore, this relative movement may separate
the anchor actuation element from the anchor or actuator attachment
element.
[0124] FIG. 27 illustrates a variation of the anchor lock element
of FIG. 26. In FIG. 27, anchor lock element 34 comprises lock
alignment feature 370. Feature 370 comprises engagement portion
372, illustratively a loop, that is adapted to engage post 32
before engagement of anchor lock element 34 (i.e., before
engagement of tab 342 of the anchor lock element) with post lock
element 260. Feature 370 ensures alignment of the post and buckle
prior to locking. Furthermore, feature 370 adds additional strength
to anchor lock element 34 and opposes inwardly-directed forces
applied to element 34 when valve 20 of apparatus 10 closes during
diastole.
[0125] Referring now to FIG. 28, actuation of the apparatus of FIG.
27 is described. As seen in FIG. 28A, anchor lock element 34 is
advanced distally relative to post 32, for example, by applying a
distally-directed force to the anchor via anchor actuator 106a to
move the proximal portion of the anchor distally while maintaining
the position of post 32 via actuator 106b. Alternatively or
additionally, a proximally-directed force may be applied to post 32
via actuator 106b while maintaining the position of the proximal
end of the anchor to move the distal portion of the anchor
proximally. Lock alignment feature 370 engages the proximal end of
the post prior to interlocking of tab 342 of anchor lock element 34
with post lock element 260, thereby ensuring proper alignment.
Continued retraction of post 32 relative to buckle 34 locks the
post into the buckle, as shown in FIG. 28B. This also expands
apparatus 10 to the fully deployed configuration of, e.g., FIGS. 1B
and 2C. Next, release actuator 112 is retracted proximally relative
to actuator 106b, which causes wrap portion 360 of the actuator to
resiliently or dynamically swing outwards, thereby bringing first
opening 362 and second opening 364 out of alignment. Proximal
retraction of actuator 106b relative to post 32 removes wrap
portion 360 from actuator attachment element 264 of post 32.
[0126] FIG. 29 shows a variation of the apparatus of FIGS. 27 and
28. In FIG. 29, anchor lock element 34 comprises locking hoop 380,
while post lock element 260 comprises a wrapped or curved proximal
end of post 32. The curved proximal end also forms actuator
attachment element 264. Wrap portion 360 of actuator 106b is
wrapped about the curved end of post 32. Release actuator 112,
passing through first opening 362 and second opening 364 of
actuator 106b, releasably secures this attachment. The release
actuator further comprises kink 390 that facilitates passage of the
actuator through release actuator attachment elements 392 of post
32, illustratively eyelets. When disposed through elements 392,
release actuator 112 further acts as a lock prevention mechanism
that precludes locking of the curved proximal end of post 32 with
hoop 380 of anchor lock element 34.
[0127] In use, the proximal end of post 32 may be retracted through
hoop 380 of anchor lock element 34. Release actuator 112 then may
be retracted relative to anchor actuator 106b and post 32, such
that the release actuator is disposed proximal of attachment
elements 392 of the post. Next, post 32 may be allowed to distally
advance until its curved proximal end catches and locks against
hoop 380 of element 34. Continued retraction of release actuator
112 relative to actuator 106b facilitates separation of the
actuator from the post, as described previously.
[0128] Referring now to FIG. 30, an embodiment of post 32 is
described that is configured to lock against the braid of anchor
30, as opposed to a separate anchor lock element 34. Post lock
element 260 illustratively comprises bent tab 400 that catches
against the anchor braid to lock the anchor in a deployed
configuration.
[0129] FIG. 31 illustrate locking and unlocking of a variation of
anchor lock element 34. Anchor lock element 34 of FIG. 31 is
similar to the buckle variation of element 34 described previously
with respect to FIGS. 25 and 26. However, the variation of FIG. 31
is fabricated from a strip of material that is bent to form a
wrapped or curved portion. FIG. 31A illustrates the apparatus prior
to locking, FIG. 31B illustrates the locked configuration, and FIG.
31C illustrates unlocking through application of a
proximally-directed unlocking force to unlock actuator 350.
[0130] FIG. 32 show yet another embodiment of a releasable
actuation mechanism. Anchor lock element 34 comprises lock
alignment mechanism 410 disposed proximal of locking tab 412. As
shown, lock alignment mechanism 410 engages the distal end of post
32 to align the post and the anchor lock element prior to locking
of post lock element 260 with tab 412 of anchor lock element 34.
Lock alignment mechanism 410 adds additional strength to anchor
lock element 34 and opposes inwardly-directed forces applied to
element 34 when valve 20 of apparatus 10 closes during diastole.
Advantageously, the inwardly-directed forces act to maintain
apparatus 10 in the locked configuration. Mechanism 410 optionally
may be formed from a cut tube.
[0131] FIG. 33 illustrate a variation of anchor lock element 34
that may be formed from a cut tube. As seen in FIGS. 33A and 33B,
element 34 comprises tabs 420 for engaging the curved proximal end
of post 32 that forms post locking element 260. In order to lock
the post to element 34, the curved distal end of the post is
retracted proximally of tabs 420 by the action of proximal tension
on post 32 by actuator 106b while element 34 is held stationary, as
described above. As it enters anchor lock element 34, the curved
end of the post is cammed inward by the engagement of the distal
edge of element 34 with the outer surface of the curved end. Once
proximal of tabs 420, the curved end of the post moves outward,
thereby locking the apparatus and preventing subsequent distal
movement of post 32 with respect to element 34. To unlock the
apparatus, the curved portion of the post is drawn further
proximally by actuator 106b until the tip of the curved portion
moves into an opening 422 formed in element 34. As seen in FIGS.
33C and 33D, resilient distal advancement of the post relative to
element 34, e.g., via resilient expansion of the braid of anchor
30, deforms and straightens the curved proximal end of post 32
through a camming engagement of the underside of the curved portion
of the post with the inner surface of opening 422, thereby allowing
actuator 106b to slide off of post 32, unlocking apparatus 10. The
curved portion of post 32 optionally may be formed from a shape
memory material, such that the post resumes its curved profile for
subsequent relocking after unlocking.
[0132] FIG. 34 illustrate a variation of post 32 and anchor lock
element 32. Anchor lock element 34 illustratively comprises a
curved portion 35 that engages and enters the slot of post lock
element 260 to lock the anchor as post 32 is drawn proximally into
element 34 by actuator 106b. After locking, continued proximal
retraction of post 32 by actuator 106b engages the distal end of
the curved portion of element 34 with a camming surface 430 of post
32. Resilient distal advancement of post 32 (such as by the
resilient contraction and elongation of the anchor to its at-rest
configuration) then deforms and straightens the wrapped end of
element 34, thereby permitting anchor lock element 34 to separate
from post 32, unlocking the apparatus.
[0133] FIGS. 35 and 36 illustrate additional buckle variations of
anchor lock element 34. Proximal movement of post 32 into anchor
lock element 34 (by, e.g., actuator 106b) engages a bottom surface
702 of a curved portion 700 of element 34 with the proximal end of
post 32. Further proximal movement of post 32 with respect to
element 34 cams curved portion 700 forward until the curved end 704
of curved portion 700 meets and resiliently moves into opening 260
in post 32, locking the apparatus. The variation of FIG. 36
illustrates attachment to the braid of anchor 30 via sutures or the
like passed through openings 340 in element 34. The lock is
unlockable via unlock actuator 350.
[0134] Referring now to FIG. 37, an embodiment of a post 32 and
anchor lock element 34 with a ratcheting lock is described. Post 32
comprises previously described actuator attachment element 250 that
is releasably secured to post attachment element 302 of actuator
106b. (Other releasable attachment mechanisms may alternatively be
used.) Post 32 also comprises braid attachment element 430 and
valve attachment structure 432. In the variation of FIG. 37, valve
attachment structure 432 comprises tab 433 that extends from post
32, as well as a plurality of holes 434 through post 32 and a
plurality of holes 435 through tab 433. Replacement valve 20 may be
attached to post 32 by sewing the valve to the valve attachment
structure through holes 434 and/or 435.
[0135] Post 32 further comprises ratcheting locking element 440
having a plurality of inclined planes with camming surfaces 442 and
friction surfaces 443. The inclined planes are disposed along
either side of tab 433 for ratcheting and locking against
ratcheting anchor lock element 34. Anchor lock element 34 comprises
ratchet teeth 450 on either side of the valve attachment elements
that cam against surface 442 and lock against friction surfaces 443
of element 440 of post 32, as post 32 is proximally retracted
through element 34. Advantageously, providing multiple rows of
inclined plane ratchets along post 32 facilitates interlocking of
the post and the element at multiple discrete locations.
[0136] Element 34 comprises proximal and distal slots 452 that
receive post 32, as well as central longitudinal slot 453 that
facilitate passage of tab 433 (and thereby valve 20) therethrough.
Actuator 106b may be disposed through slots 452 prior to
approximation and locking of the post to anchor lock element 34 in
order to facilitate alignment of the post and the anchor lock
element. Element 34 may be ratcheted to any position along ratchet
lock element 440 to achieve any desired locking configuration and
degree of expansion of apparatus 10. Valve attachment structure
432, and thereby replacement valve 20, may be positioned proximal
of the ratchet lock post-deployment or in line with the ratchet
lock (i.e., neither proximal nor distal to the ratchet lock).
Element 34 further comprises unlock actuator attachment(s) 454 for
coupling the element to an unlock actuator, e.g., previously
described unlock actuator 350, to unlock element 34 by applying a
proximally-directed unlocking force that displaces ratchet teeth
450 from friction surfaces 443.
[0137] FIG. 38 illustrate variations of the apparatus of FIG. 37.
Ratchet lock elements 440 of posts 32 in FIG. 38 comprise a
plurality of ratchet slots 444 in which ratchet tooth 450 of anchor
lock element 34 may be locked. Ratchet tooth 450 comprises proximal
friction surface 456 and distal camming surface 457 to facilitate
proximal retraction of a post 32 through slot 452 for ratcheting of
camming surface 457 through ratchet slots 444, but to preclude
distal advancement of the post once ratchet tooth 450 is engaged
within ratchet slots 444 by locking a ratchet slot against friction
surface 456. As with the variation of FIG. 37, anchor lock element
34 is unlockable and comprises unlock actuator attachment 454. In
contrast to the variation of FIG. 37, the ratchet lock is disposed
proximally of valve attachment structure 432, and thereby
proximally of replacement valve 20. In FIG. 38A, valve attachment
structure 432 comprises slot 436 instead of tab 433.
[0138] FIG. 39 illustrate another variation of the ratchet lock of
FIG. 37. In FIG. 39, ratchet lock elements 440 of post 32 extend
along only one edge of the post. Thus, anchor lock element 34
comprises unitary ratchet tooth 450 for camming against surfaces
442 and locking against friction surfaces 443 of elements 440 of
post 32, as post 32 is proximally retracted through element 34.
[0139] The apparatus of FIG. 39 also comprises unlock or adjustment
actuator 500 that is releasably attached to anchor lock element 34
along unlock actuator attachment 454. Actuator 500 comprises two
independently or concurrently actuable elements: adjustment element
510 and release element 520. Adjustment element 510 comprises
elongated member 512 having protrusion 514 with lumen 515, as well
as distal extension 516 with notch 518 having optional camming
surface 519. Release element 520 comprises elongated member 521,
which may, for example, comprise a mandrel, that is configured for
passage through lumen 515 of protrusion 514 of adjustment element
510. Elongated members 512 and 521 of actuator 500 preferably
extend through delivery system 100 to the exterior of the patient
for independent or concurrent advancement and/or retraction by a
medical practitioner.
[0140] As seen in FIG. 39A, notch 518 of adjustment element 510 of
actuator 500 may be positioned within unlock actuator attachment
454 of anchor lock element 34 during deployment of apparatus 10. As
seen in FIG. 39B, anchor lock element 34 is locked within
ratcheting lock elements 440 of post 32 by proximally retracting
actuator 106b relative to anchor lock element 34. Release element
520 then may be advanced relative to adjustment element 510 to
position elongated member 521 within unlock actuator attachment 454
adjacent distal extension 516 of adjustment element 510. This
serves to friction lock or interference fit actuator 500 within
attachment 454 along notch 518 of adjustment element 510. Thus,
concurrent advancement and/or retraction of the adjustment and
release elements of actuator 500 by a medical practitioner causes
anchor lock element 34 to move in unison with actuator 500. As will
be apparent, actuator 500 alternatively may be friction locked with
anchor lock element 34 prior to full deployment of apparatus 10.
Furthermore, actuator(s) 500 may assist, or be used in place of,
actuators 106a to deploy apparatus 10.
[0141] As seen in FIG. 39C, the lock formed between anchor lock
element 34 and post 32 may be unlocked or adjusted, as desired, by
applying a lateral unlocking force to ratchet tooth 450 via
actuator 500 that pulls the ratchet tooth away from a friction
surface 443 of ratcheting lock elements 440. Actuator 500 then may
be distally advanced or, as seen in FIG. 39D, proximally retracted
relative to ratcheting lock elements 440 and post 32 to further
expand or partially collapse anchor 30, respectively (further
expansion alternatively may be achieved by further ratcheting
ratchet tooth 450 along camming surface 442 of ratcheting lock
elements 440, e.g., by further proximally retracting actuator 106b,
which is not shown in FIGS. 39C-39F for the sake of clarity).
Anchor actuation elements 106 may assist such controlled expansion
or collapse anchor 30.
[0142] When (re-)positioned at a desired location and/or when a
desired degree of locking has been achieved, the lateral unlocking
force may be removed from ratchet tooth 450 to again lock anchor
lock element 34 to post 32 along ratcheting lock elements 440, as
in FIG. 39E. To complete deployment of apparatus 10, adjustment
actuator 500 and actuator 106b, as well as actuator 106a (not
shown), may be separated from the apparatus. In FIG. 39F, release
element 520 of actuator 500 is proximally retracted relative to
adjustment element 510, thereby removing elongated member 521 of
release element 520 from unlock actuator attachment 454 of anchor
lock element 34. This removes the interference fit between notch
518 and attachment 454. Proximal retraction of actuator 500
relative to anchor lock element 34 detaches adjustment element 510
of actuator 500 from attachment 454 of anchor lock element 34, as
in FIG. 39G. Optional camming surface 519 along notch 518 may
facilitate such detachment. In FIG. 39H, actuator 106b is detached
from post 32 by retracting release actuator 112 relative to the
actuator, as described previously.
[0143] Referring now to FIG. 40, another variation of an adjustable
ratcheting lock element is described. As seen in FIG. 40A, post 32
comprises tube 470 having lumen 471 and ratcheting lock element
472, illustratively a plurality of slots that communicate with
lumen 471. Post 32 also comprises valve support structure or
attachment element 474 and braid attachment element 476.
[0144] Anchor lock element 34, which may be fabricated from a cut
tube, comprises a substantially cylindrical structure having braid
attachment element 480, lumen 482 and tabs 484. As seen in the top
view of FIG. 40B, tabs 484 of anchor lock element 34 are configured
for locking within the slots of ratcheting lock element 472 of post
32. As seen in the top view of FIG. 40C, adjustment actuator 490,
illustratively mandrel M having tapered distal end 494 that acts as
a camming surface, may be advanced through lumen 481 of anchor lock
element 34 and lumen 471 of tube 470 of post 32, to displace tabs
484 from the locking slots of post 32, thereby unlocking the post
from the anchor lock element. This facilitates, for example,
readjustment of a degree of locking/expansion of apparatus 10,
repositioning of apparatus 10, retrieval of apparatus 10, etc.
[0145] FIG. 41 illustrate a variation of anchor lock element 34
wherein tabs 484 are positioned along a different axis. This may
provide a more secure lock between post 32 and anchor lock element
34. FIG. 42 illustrate a variation of post 32 configured for use
with the variation of anchor lock element 34. In FIG. 32, post 32
comprises groove 478 that connects the slots of ratcheting lock
element 472. Groove 478 does not communicate with lumen 471 of tube
470 of post 32. Rather, the groove may act as a lock alignment
mechanism that guides tabs 484 of anchor lock element 34 along post
32 and ratcheting lock element 472, as seen in the top view of FIG.
42B.
[0146] Referring now to FIG. 43, a method of actuating the
variation of FIG. 41 is described. As seen in FIG. 43A, adjustment
actuator 490 is initially disposed through lumen 482 of anchor lock
element 34 and within lumen 471 of post 32. Post 32 then may be
proximally retracted relative to anchor lock element 34, e.g., via
actuator 106b (not shown). In FIG. 43B, actuator 490 serves as a
lock prevention mechanism that precludes locking of tabs 484 within
ratcheting lock element 472. In FIG. 43C, actuator 490 is retracted
relative to post 32 and anchor lock element 34, which opens up
lumen 471 of tube 470 and allows tabs 484 to pass through the slots
of ratcheting lock element 472, thereby locking the post to the
anchor lock element. In FIG. 43D, actuator 490 is re-advanced
within lumen 471, such that tapered distal end 494 of mandrel M
serves as a camming surface that urges tabs 484 out of lumen 471 as
the actuator is advanced. This unlocks the post from the anchor
lock element to facilitate adjustment, repositioning or retrieval
of apparatus 10. In FIG. 43E, a degree of locking/expansion of the
apparatus is adjusted by repositioning anchor lock element 34
relative to post 32, and thereby tabs 484 relative to ratcheting
lock element 472. When properly adjusted, actuator 490 may be
removed from lumen 471 of tube 470 of post 32, as in FIG. 43F. Tabs
484 resiliently return to the locked configuration within the slots
of ratcheting lock element 472.
[0147] Referring now to FIG. 44, an embodiment of anchor/actuator
106a is described. Actuator 106a comprises elongated member 600
having proximal extension 602 that may be attached, for example, to
previously described multi-lumen shaft or catheter 108 of delivery
system/deployment tool 100 (see FIG. 1), e.g., via epoxy, UV
curing, etc. Lumen 601 extends through elongated member 600 from
proximal extension 602 to releasable attachment mechanism 604.
Releasable attachment mechanism 604 releasably attached actuator
106a to the braid of anchor 30. The mechanism comprises release
actuator 112 and illustratively is similar to the previously
described releasable attachment mechanism of FIGS. 26-28. Release
actuator 112, illustratively a mandrel, passes through a lumen Lu
of multi-lumen shaft 108 and then through lumen 601 of actuator
106a to mechanism 604.
[0148] Actuator 106a further comprises shaping features 606 that
affect a shape of the anchor actuator when an anchor actuation
force is applied to anchor 30. These features may comprise, for
example, reduced diameter portions of the actuator, reduced wall
thickness portions of the actuator and/or slits formed in the
anchor actuator. Application of an anchor actuation force may, for
example, provide actuator 106a with the profile seen in FIG. 44A.
This profile may facilitate expansion of anchor 30/apparatus 10. As
will be apparent, shaping features may be provided with any anchor
actuation elements 106, including any of the previously described
variations of actuators 106b.
[0149] As seen in FIG. 45, releasable attachment mechanism 604
comprises wrap portion 610 that may, for example, pass through the
braid of anchor 30 and wrap around the proximal end of the anchor.
Wrap portion 610 may comprise a shape memory material, such as
Nitinol, or a deformable material, e.g., a resiliently deformable
material. The wrap portion comprises first opening 612 for engaging
release actuator 112. The walls of lumen 601 of elongated member
600 may act as a linear bearing and/or motion guide during
advancement and retraction of the release actuator relative to the
actuator. Actuator 106a also comprises second opening 614, which
may be aligned with first opening 612 to engage release actuator
112, as shown. Wrap portion 610, and especially curved portion 611
of the wrap portion, acts as a spring element that urges the first
opening out of alignment with the second opening to engage and hold
release actuator 112 in place.
[0150] As seen in FIG. 45C, when the release actuator is retracted
proximally relative to the actuator, wrap portion 610 resiliently
or dynamically swings outwards. Thereafter, proximal retraction of
anchor actuator 106a relative to anchor 30 detaches wrap portion
610, and thereby actuator 106a, from the anchor. Surface 616 of
wrap portion 610 may act as a camming surface as the inner surface
of wrap portion 610 slides along the anchor braid 30 to facilitate
such detachment.
[0151] In this manner, release actuator 112 may be interference or
friction fit through first opening 612 and second opening 614.
Retraction of the release actuator proximal of the first and second
openings actuates releasable attachment mechanism 604 to
resiliently or dynamically unwrap portion 610 and release actuator
106a from anchor 30. Wrap portion 610 of actuator 106a
illustratively is disposed at a distal end of the actuator.
[0152] With reference to FIG. 46, a variation of releasable
attachment mechanism 604 is described. In FIG. 46, wrap portion 610
illustratively comprises tabs 618 that act as an alignment
mechanism for aligning the wrap portion of mechanism 604 with
elongated member 600. This may facilitate advancement of release
actuator 112 through mechanism 604. FIG. 47 illustrate a variation
of tabs 618 wherein the tabs are rounded. This may reduce friction,
provide an atraumatic surface, etc. Additional shapes for tabs 618
will be apparent. Alternatively, tabs 618 may act as spring
elements which are loaded when element 630 is seated, as shown in
FIG. 47B. In this configuration tabs 618 apply a force directed
towards element 630 such that 630 will be ejected when element 112
is retracted. In this way tabs 618 apply a restraining force on
element 112 which reduces the risk of an early release.
[0153] FIG. 48 illustrate a variation of wrap portion 610 that
comprises a substantially straight distal region in an at-rest
configuration, as seen in FIG. 48C. It is expected that providing a
substantially straight distal region along wrap portion 610 may
facilitate detachment of actuator 106a from anchor 30, i.e., may
reduce a risk of snagging the wrap portion along the braid of the
anchor. The wrap portion may be resiliently deformed for passage of
release actuator 112 through first opening 612, as in FIGS. 48A and
48B.
[0154] Referring now to FIG. 49, variations of release actuator 112
for use with releasable attachment mechanism 604 are described. In
FIG. 49A, the release actuator comprises a simple mandrel. In FIGS.
49B and 49C, the release actuator comprises protrusion 620 having
friction surface 621. In FIG. 49D, actuator 112 comprises coil 622.
In FIGS. 49E-49H, the actuator comprises kink 624, which may act as
a camming surface, as shown. The kink may also provide tactile
feedback to a medical practitioner. In FIGS. 49I and 49J, the
release actuator comprises ball or knob 626 disposed proximal of
the actuator's distal end. In FIGS. 49K and 49L, ball 626 is
disposed at the distal end of actuator 112. The ball may act as a
camming surface. In FIG. 49M, actuator 112 comprises protrusion 628
having proximal camming surface 629. In FIG. 49N, the actuator
comprises oblong protrusion 430 having friction surface 431.
Additional variations of actuator 112 will be apparent.
[0155] Referring now to FIG. 50, an embodiment of delivery
system/deployment tool 100 is described. FIG. 50A provides a detail
view of multi-lumen catheter 108 and sheath 110. As discussed
previously catheter 108 comprises central lumen 109 and a plurality
of circumferentially-disposed lumens Lu.
[0156] As seen in FIG. 50B, actuator 106a is coupled to catheter
108 via proximal extension 602, such that lumen 601 is coaxially
disposed within a lumen Lu of the catheter. Release actuator 112
extends through lumens Lu and 601. Actuator 106a is distally
attached to the braid of anchor 30 along releasable attachment
mechanism 604. For the sake of clarity, a single actuator 106a is
shown in FIG. 50B, but multiple such actuators preferably are
provided, as in FIG. 51 described hereinafter.
[0157] FIG. 50B also illustrates actuator 106b. The actuator
extends through a lumen Lu of catheter 108 and through anchor lock
element 34 to post 32 (not shown). Unlock actuator 350 is also
provided and extends through a lumen Lu to unlock actuator
attachment 344 of anchor lock element 34. Anchor lock element 34
illustratively comprises the variation described previously with
respect to FIG. 31. The element is attached to the braid of anchor
30 along anchor attachment elements 340. As with actuator 106a, a
single anchor lock element 34 and actuator 106b are shown in FIG.
50B. This is only for the sake of clarity, and multiple such
actuators may be provided, e.g., three actuators.
[0158] Referring now to FIG. 51, delivery system/deployment tool
100 is shown with a plurality of actuators 106a and actuators 106b
for releasable attachment to anchor 30 of apparatus 10. In FIG.
51A, anchor actuation elements 106a are coupled to the anchor. In
FIG. 51B, the elements are decoupled from the anchor.
[0159] With reference now to FIG. 52, a variation of the delivery
system/deployment tool of FIGS. 50 and 51 is described comprising a
plurality of arms or actuators that extend from a unitary
structure. Unitary structure 650, which may extend from a distal
region of multi-lumen shaft 108, is preferably fabricated from a
laser-cut tube. Structure 650 comprises a plurality of
circumferentially disposed arms 652 that serve as actuators.
Expansile elements 654 may be disposed between arms 652 and
facilitate constraint of the arms radially outward or inward with
respect to other arms as the anchor reshapes. FIG. 52A shows the
arms in a radially collapsed configuration, and FIG. 52B shows the
arms in a radially expanded configuration. Wrap portions 655 are
adapted to wrap around the proximal portion of an anchor braid.
Openings 656 and 657 are formed in wrap portions 655 to engage a
release actuator, as described in embodiments above.
[0160] Referring now to FIG. 53, various ways to connect elements
to the braid of anchor 30 of replacement valve apparatus 10 are
described. In FIG. 53A, a post 32 having a single braid attachment
hole 660 is attached to anchor 30 along three separate
intersections of the braid via suture S. FIG. 53B provides a detail
view of one exemplary technique for routing the suture between hole
660 and anchor 30. FIG. 53C illustrates a variation of the
attachment, wherein post 32 comprises multiple braid attachment
holes 660. As will be apparent, elements other than posts 32 may be
attached to anchor 30 in the manner described, for example, anchor
lock elements 34 may be attached in a similar manner.
[0161] While preferred embodiments of the present invention are
shown and described herein, it will be obvious to those skilled in
the art that such embodiments are provided by way of example only.
Numerous variations, changes, and substitutions will occur to those
skilled in the art without departing from the invention. For
example, while the invention was described in connection with the
replacement of a natural valve, the invention may also be used to
replace an earlier-implanted prosthetic valve. Also, while the
preceding discussion described the use of the invention to deliver
and deploy replacement heart valves, it should be understood that
the invention is not limited to that particular use. Other aspects
of the invention include methods and apparatuses for
endovascularly, percutaneously and/or endoscopically delivering and
deploying expandable devices in a patient and optionally detaching
a deployment tool from the device.
[0162] It should be understood that various alternatives to the
embodiments of the invention described herein may be employed in
practicing the invention. It is intended that the following claims
define the scope of the invention and that methods and structures
within the scope of these claims and their equivalents be covered
thereby.
* * * * *