U.S. patent application number 16/936045 was filed with the patent office on 2020-11-12 for implantable heart valve devices, mitral valve repair devices and associated systems and methods.
The applicant listed for this patent is Twelve, Inc.. Invention is credited to Hanson S. Gifford, III.
Application Number | 20200352707 16/936045 |
Document ID | / |
Family ID | 1000004975015 |
Filed Date | 2020-11-12 |
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United States Patent
Application |
20200352707 |
Kind Code |
A1 |
Gifford, III; Hanson S. |
November 12, 2020 |
IMPLANTABLE HEART VALVE DEVICES, MITRAL VALVE REPAIR DEVICES AND
ASSOCIATED SYSTEMS AND METHODS
Abstract
Systems, devices and methods for repairing a native heart valve.
In one embodiment, a repair device for repairing a native mitral
valve having an anterior leaflet and a posterior leaflet between a
left atrium and a left ventricle comprises a support having a
contracted configuration and an extended configuration. In the
contracted configuration, the support is sized to be inserted under
the posterior leaflet between a wall of the left ventricle and
chordae tendineae. In the extended configuration, the support is
configured to project anteriorly with respect to a posterior wall
of the left ventricle by a distance sufficient to position at least
a portion of the posterior leaflet toward the anterior leaflet.
Inventors: |
Gifford, III; Hanson S.;
(Woodside, CA) |
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Applicant: |
Name |
City |
State |
Country |
Type |
Twelve, Inc. |
Redwood City |
CA |
US |
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|
Family ID: |
1000004975015 |
Appl. No.: |
16/936045 |
Filed: |
July 22, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16132301 |
Sep 14, 2018 |
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16936045 |
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14892171 |
Nov 18, 2015 |
10111747 |
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PCT/US2014/038849 |
May 20, 2014 |
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16132301 |
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61825491 |
May 20, 2013 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61F 2250/0025 20130101;
A61F 2/2466 20130101; A61F 2230/0017 20130101; A61F 2/2412
20130101; A61F 2250/0069 20130101; A61F 2/2478 20130101; A61F
2210/0061 20130101; A61F 2210/0014 20130101; A61F 2/2487 20130101;
A61F 2230/0008 20130101; A61F 2/246 20130101; A61F 2250/003
20130101; A61F 2250/0039 20130101; A61F 2/2445 20130101; A61F
2/2442 20130101; A61F 2210/0085 20130101; A61F 2/2409 20130101;
A61F 2250/0096 20130101; A61F 2/2454 20130101; A61F 2230/0023
20130101 |
International
Class: |
A61F 2/24 20060101
A61F002/24 |
Claims
1. A mitral valve repair device, comprising: a frame comprising a
shape memory material; and an extension unit positioned around at
least a portion of the frame, the extension unit comprising a
flexible material configured to move from a contracted
configuration for delivery to an expanded configuration, the
extension unit having an inner volume configured to be filled with
blood in the expanded configuration, and the extension unit
configured to extend inwardly toward a central axis of an orifice
of a native mitral valve to close a gap relative to a free edge of
an anterior leaflet of the native mitral valve in the expanded
configuration.
2. The mitral valve repair device of claim 1, wherein the flexible
material comprises a cover, and wherein the cover is configured to
enable tissue ingrowth.
3. The mitral valve repair device of claim 1, wherein, when in the
contracted configuration, the frame and the extension unit are
sized to fit within a delivery catheter.
4. The mitral valve repair device of claim 1, wherein the extension
unit comprises a fluid absorbing material within the inner
volume.
5. The mitral valve repair device of claim 4, wherein the fluid
absorbing material comprises a foam.
6. The mitral valve repair device of claim 4, wherein the fluid
absorbing material comprises a hydrogel.
7. The mitral valve repair device of claim 4, wherein, when in
contact with the blood, the fluid absorbing material is configured
to expand to inflate the extension unit from the contracted
configuration to the expanded configuration.
8. The mitral valve repair device of claim 1, wherein the extension
unit is configured to push at least a portion of a posterior
leaflet of the native mitral valve toward the anterior leaflet of
the native mitral valve.
9. The mitral valve repair device of claim 1, wherein the extension
unit comprises an inflatable bladder within the inner volume and
extending the extension unit comprises injecting the blood into the
inflatable bladder.
10. The mitral valve repair device of claim 1, wherein the frame is
configured to, in response to deployment from a delivery catheter,
move from a collapsed configuration toward a deployed
configuration, and wherein, when in the deployed configuration, the
frame is configured to press against an underside of a posterior
leaflet of the native mitral valve.
11. The mitral valve repair device of claim 1, wherein the
extension unit comprises a plurality of projections and a plurality
of depressions, each depression being disposed between two of the
projections, wherein at least some of the projections are
configured to engage an underside of a posterior leaflet of the
native mitral valve, and wherein at least some of the depressions
are configured to receive chordae tendineae coupled to the
underside of the posterior leaflet.
12. A method of repairing a native mitral valve having an anterior
leaflet and a posterior leaflet between a left atrium and a left
ventricle, comprising: implanting a mitral valve repair device
under the posterior leaflet, wherein the mitral valve repair device
comprises: a frame defined by a shape memory material; and an
extension unit positioned around at least a portion of the frame,
the extension unit comprising a flexible material configured to
move from a contracted configuration for delivery to an expanded
configuration; and inflating, with blood, an inner volume of the
extension unit to move the flexible material from the contracted
configuration to the expanded configuration and to extend inwardly
toward a central axis of the valve orifice to close a gap relative
to a free edge of an anterior leaflet of a native mitral valve in
the expanded configuration.
13. The method of claim 12, wherein positioning the mitral valve
repair device under the posterior leaflet comprises positioning the
extension unit in the contracted configuration under the posterior
leaflet, and wherein inflating the at least one pocket comprises
expanding the cover to presses against a wider portion of the
posterior leaflet in the expanded configuration relative to the
contracted configuration.
14. The method of claim 12, wherein the method further comprises,
before inflating the at least one pocket, releasing the frame from
a collapsed configuration such that the frame moves toward a
deployed configuration to press against an underside of the
posterior leaflet.
15. The method of claim 12, wherein the extension unit comprises a
plurality of projections and a plurality of depressions, each
depression being disposed between two of the projections, and
wherein inflating the at least one pocket comprises extending the
projections along an underside of the posterior leaflet such that
an upper side of the projections presses against the posterior
leaflet and the chordae tendineae are positioned in at least some
of the depressions.
16. The method of claim 12, wherein inflating the at least one
pocket further comprises closing a gap relative to free edges of
the posterior leaflet and the anterior leaflet.
17. A medical system for repairing a native valve of a patient, the
system comprising: a delivery catheter extending from a proximal
portion controllable by a clinician to a distal portion
introducible into a vasculature of a patient; and a valve repair
device positioned within the distal portion of the delivery
catheter, wherein the valve repair device comprises: a frame
defined by a shape memory material; and an extension unit
positioned around at least a portion of the frame, the extension
unit comprising a flexible material configured to move from a
contracted configuration for delivery to an expanded configuration,
the extension unit having an inner volume configured to be filled
with blood in the expanded configuration, wherein the delivery
catheter is configured to deploy the valve repair device in the
contracted configuration into a subannular position behind at least
one leaflet of a native valve connected to chordae tendineae, and
wherein the extension unit, when in the expanded configuration, is
configured to extend inwardly toward a central axis of an orifice
of the native valve to close a gap relative to a free edge of the
at least one leaflet of the native valve in the expanded
configuration.
18. The medical system of claim 17, wherein the native valve is a
mitral valve, and wherein the heart wall is a left ventricular wall
and the leaflet is a posterior mitral valve leaflet.
19. The medical system of claim 17, wherein the chordae tendineae
are basal or tertiary chordae tendineae.
20. The medical system of claim 17, wherein the valve repair device
is configured to engage the heart wall and the underside of the at
least one leaflet without penetrating the heart wall tissue or the
leaflet.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application is a Continuation of U.S. patent
application Ser. No. 16/132,301, which is a Divisional of U.S.
patent application Ser. No. 14/892,171, now allowed, which is a 35
U.S.C. .sctn. 371 of International Application No.
PCT/US2014/038849, filed May 20, 2014, which claims priority to
U.S. Provisional Patent Application No. 61/825,491, filed May 20,
2013. Each of these applications is incorporated by reference in
its entirety.
TECHNICAL FIELD
[0002] The present technology relates generally to implantable
heart valve devices. In particular, several embodiments are
directed to mitral valve devices for percutaneous repair of native
mitral valves and associated systems and methods for repair and/or
replacement of native mitral valves.
BACKGROUND
[0003] Conditions affecting the proper functioning of the mitral
valve include, for example, mitral valve regurgitation, mitral
valve prolapse and mitral valve stenosis. Mitral valve
regurgitation is a disorder of the heart in which the leaflets of
the mitral valve fail to coapt into apposition at peak systolic
contraction pressures such that blood leaks abnormally from the
left ventricle into the left atrium. There are a number of
structural factors that may affect the proper closure of the mitral
valve leaflets.
[0004] One structural factor that causes the mitral valve leaflet
to separate is dilation of the heart muscle. FIG. 1A is a schematic
illustration of a native mitral valve showing normal coaptation
between the anterior mitral valve leaflet (AMVL) and the posterior
mitral valve leaflet (PMVL), and FIG. 1B is a schematic
illustration of a native mitral valve following a myocardial
infarction which has dilated the ventricular free wall to an extent
that mitral valve regurgitation has developed. Functional mitral
valve disease is characterized by dilation of the left ventricle
and a concomitant enlargement of the mitral annulus. As shown in
FIG. 1B, the enlarged annulus separates the free edges of the
anterior and posterior leaflets from each other such that the
mitral leaflets do not coapt properly. The enlarged left ventricle
also displaces the papillary muscles further away from the mitral
annulus. Because the chordae tendineae are of a fixed length,
displacement of the papillary displacement can cause a "tethering"
effect that can also prevent proper coaptation of the mitral
leaflets. Therefore, dilation of the heart muscle can lead to
mitral valve regurgitation.
[0005] Another structural factor that can cause abnormal backflow
is compromised papillary muscle function due to ischemia or other
conditions. As the left ventricle contracts during systole, the
affected papillary muscles do not contract sufficiently to effect
proper closure of the valve. This in turn can lead to mitral valve
regurgitation.
[0006] Treatment for mitral valve regurgitation has typically
involved the application of diuretics and/or vasodilators to reduce
the amount of blood flowing back into the left atrium. Other
procedures have involved surgical approaches (open and
intravascular) for either the repair or replacement of the valve.
Replacement surgery, either done through large open thoracotomies
or less invasively through a percutaneous approach, can be
effective, but there are compromises of implanting a prosthetic
valve. For example, prosthetic mechanical valves require a lifetime
of anticoagulation therapy and risks associated with stroke or
bleeding. Additionally, prosthetic tissue valves have a finite
lifetime, eventually wearing out, for example, over twelve or
fifteen years. Therefore, valve replacement surgeries have several
shortcomings.
[0007] Mitral valve replacement also poses unique anatomical
obstacles that render percutaneous mitral valve replacement
significantly more challenging than other valve replacement
procedures, such as aortic valve replacement. First, aortic valves
are relatively symmetric and uniform, but in contrast the mitral
valve annulus has a non-circular D-shape or kidney-like shape, with
a non-planar, saddle-like geometry often lacking symmetry. Such
unpredictability makes it difficult to design a mitral valve
prosthesis having that properly conforms to the mitral annulus.
Lack of a snug fit between the prosthesis and the native leaflets
and/or annulus may leave gaps therein that allows backflow of blood
through these gaps. Placement of a cylindrical valve prosthesis,
for example, may leave gaps in commissural regions of the native
valve that cause perivalvular leaks in those regions. Thus, the
anatomy of mitral valves increases the difficulty of mitral valve
replacement procedures and devices.
[0008] In addition to its irregular, unpredictable shape, which
changes size over the course of each heartbeat, the mitral valve
annulus lacks radial support from surrounding tissue. The aortic
valve, for example, is completely surrounded by fibro-elastic
tissue that provides good support for anchoring a prosthetic valve
at a native aortic valve. The mitral valve, on the other hand, is
bound by muscular tissue on the outer wall only. The inner wall of
the mitral valve is bound by a thin vessel wall separating the
mitral valve annulus from the inferior portion of the aortic
outflow tract. As a result, significant radial forces on the mitral
annulus, such as those imparted by an expanding stent prostheses,
could lead to impairment of the inferior portion of the aortic
tract.
[0009] Typical mitral valve repair approaches have involved
cinching or resecting portions of the dilated annulus. Cinching of
the annulus has been accomplished by implanting annular or
peri-annular rings that are generally secured to the annulus or
surrounding tissue. Other repair procedures have also involved
suturing or clipping of the valve leaflets into partial apposition
with one another. For example, the Evalve (Abbott Vascular)
MitraClip.RTM. clips the two mitral valve leaflets together in the
region where the leaflets fail to coapt to thereby reduce or
eliminate regurgitation. Mitral valve repair surgery has proven
effective, and especially for patients with degenerative disease.
Repair surgery typically involves resecting and sewing portions of
the valve leaflets to optimize their shape and repairing any torn
chordae tendineae, and such surgeries usually include placement of
an annuloplasty ring to shrink the overall circumference of the
annulus in a manner that reduces the anterior-posterior dimension
of the annulus.
[0010] Efforts to develop technologies for percutaneous mitral
annuloplasty that avoid the trauma, complications, and recovery
process associated with surgery, have led to devices and methods
for cinching the annulus via the coronary sinus, or cinching the
annulus via implantation of screws or anchors connected by a
tensioned suture or wire. In operation, the tensioned wire draws
the anchors closer to each other to cinch (i.e., pull) areas of the
annulus closer together. Additional techniques proposed previously
include implanting paired anchors on the anterior and posterior
areas of the annulus and pulling them together, and using RF energy
to shrink the annular tissue among other approaches.
[0011] However, all of these percutaneous annuloplasty approaches
have eluded meaningful clinical or commercial success to date, at
least partly due to the forces required to change the shape of the
native annulus, which is relatively stiff and is subject to
significant loads due to ventricular pressure. Furthermore, many of
the surgical repair procedures are highly dependent upon the skill
of the cardiac surgeon where poorly or inaccurately placed sutures
may affect the success of procedures. Overall, many mitral valve
repair and replacement procedures have limited durability due to
improper sizing or valve wear.
[0012] Given the difficulties associated with current procedures,
there remains the need for simple, effective, and less invasive
devices and methods for treating dysfunctional heart valves, for
example, in patients suffering functional mitral valve disease.
SUMMARY
[0013] At least some embodiments are directed to a method of
repairing a native mitral valve having an anterior leaflet and a
posterior leaflet between a left atrium and a left ventricle. A
repair device having a support can be implanted under the posterior
leaflet. The support can be pressed against a portion of an
underside of the posterior leaflet and thereby push at least a
portion of the posterior leaflet toward the anterior leaflet.
[0014] In some embodiments, a method of repairing a native mitral
valve having an anterior leaflet and a posterior leaflet between a
left atrium and a left ventricle includes positioning a repair
device in the left ventricle under the posterior leaflet and
between a wall of the left ventricle and chordae tendineae. The
repair device can engage an underside of the posterior leaflet such
that a portion of the posterior leaflet moves toward the anterior
leaflet.
[0015] At least some embodiments are directed to a method for
repairing a native valve of a patient and includes positioning a
heart valve repair device in a subannular position behind at least
one leaflet connected to chordae tendineae. The repair device has a
support in an unexpanded configuration. The support in the
subannular position is expanded such that the support engages an
interior surface of a heart wall and a downstream-facing surface of
the leaflet. The repair device is configured to reposition the
leaflet into an at least partially closed position and brace the
leaflet to affect native valve function. In some embodiments, the
repair device is configured to improve function of the native valve
by bracing the leaflet.
[0016] In some embodiments, a repair device for repairing a native
mitral valve having an anterior leaflet and a posterior leaflet
between a left atrium and a left ventricle comprises a support
having (a) a contracted configuration in which the support is sized
to be inserted under the posterior leaflet between a wall of the
left ventricle and chordae tendineae and (b) an extended
configuration in which the support projects anteriorly with respect
to a posterior wall of the left ventricle by a distance sufficient
to position at least a portion of the posterior leaflet toward the
anterior leaflet sufficiently to improve coaptation of the
posterior and anterior leaflets.
[0017] In some embodiments, a heart valve repair device to treat a
native valve of a patient comprises a support implantable in a
subannular position relative to the native valve. The support can
be configured to engage an interior surface of a heart wall and an
outward-facing surface of a leaflet of the native valve in the
subannular position such that the support repositions the leaflet
into a desired position (e.g., at least partially closed
position).
[0018] In further embodiments, a heart valve repair device to treat
a native valve of a patient comprises a frame have a first end
configured to be placed at least proximate a first commissure of
the native valve, a second end configured to be placed at least
proximate a second commissure of the native valve, and a curved
region between the first and second ends. The curved region of the
frame is configured to engage a backside of a leaflet of the native
heart valve so as to reposition the leaflet such that the leaflet
at least partially coapts with an adjacent leaflet of the native
valve.
[0019] In some embodiments, a system to treat a native valve of a
patient comprises a prosthetic valve repair device implantable in a
subannular position relative to the native valve. The repair device
includes a support configured to engage an interior surface of a
heart wall and an outward-facing surface of a leaflet of the native
valve in a subannular position of the native valve. The support is
configured to change an effective annulus shape and/or an effective
annulus cross-sectional dimension when the device is in a deployed
configuration. In certain embodiments, the system further includes
a prosthetic valve having a radially expandable support structure
with a lumen and a valve in the lumen and coupled to the support
structure. The radially expandable support structure is configured
to be deployed within the native valve when the prosthetic valve
repair device is implanted in the subannular position and supported
within the changed annulus shape or changed annulus cross-sectional
dimension.
[0020] At least some embodiments are directed to a valve repair
device that comprises means for supporting a posterior leaflet. The
means for supporting the posterior leaflet has contracted
configuration for insertion under the posterior leaflet between a
wall of the left ventricle and chordae tendineae and an extended
configuration for projecting anteriorly with respect to a posterior
wall of the left ventricle. In one embodiment, the means for
supporting extends a distance sufficient to position at least a
portion of the posterior leaflet toward the anterior leaflet to
affect coaptation of the posterior and anterior leaflets. In one
embodiment, the means for supporting includes one or more
extensions units expandable using one or more filler materials. The
means for supporting can further include an elongated spine coupled
to the extension unit(s).
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Many aspects of the present disclosure can be better
understood with reference to the following drawings. The components
in the drawings are not necessarily to scale. Instead, emphasis is
placed on illustrating clearly the principles of the present
disclosure. Furthermore, components can be shown as transparent in
certain views for clarity of illustration only and not to indicate
that the illustrated component is necessarily transparent.
[0022] FIG. 1A is a schematic illustration of a native mitral valve
showing normal coaptation between the anterior mitral valve leaflet
and the posterior mitral valve leaflet.
[0023] FIG. 1B is a schematic illustration of a native mitral valve
following myocardial infarction which has caused the ventricular
free wall to dilate, and wherein mitral valve regurgitation has
developed.
[0024] FIGS. 2 and 3 are schematic illustrations of a mammalian
heart having native valve structures.
[0025] FIG. 4 is a schematic cross-sectional side view of a native
mitral valve showing the annulus and leaflets.
[0026] FIG. 5 is a schematic illustration of a heart in a patient
suffering from cardiomyopathy, and which is suitable for
combination with various prosthetic heart valve repair devices in
accordance with embodiments of the present technology.
[0027] FIG. 6A is a schematic illustration of a native mitral valve
of a heart showing normal closure of native mitral valve
leaflets.
[0028] FIG. 6B is a schematic illustration of a native mitral valve
of a heart showing abnormal closure of native mitral valve leaflets
in a dilated heart, and which is suitable for combination with
various prosthetic heart valve repair devices in accordance with
embodiments of the present technology.
[0029] FIG. 6C is a schematic illustration of a mitral valve of a
heart showing dimensions of the annulus, and which is suitable for
combination with various prosthetic heart valve repair devices in
accordance with embodiments of the present technology.
[0030] FIGS. 7 and 8 are schematic cross-sectional illustrations of
the heart showing retrograde approaches to the native mitral valve
through the aortic valve and arterial vasculature in accordance
with various embodiments of the present technology.
[0031] FIG. 9 is a schematic cross-sectional illustration of the
heart showing an approach to the native mitral valve using a
trans-apical puncture in accordance with various embodiments of the
present technology.
[0032] FIG. 10A is a schematic cross-sectional illustration of the
heart showing an antegrade approach to the native mitral valve from
the venous vasculature in accordance with various embodiments of
the present technology.
[0033] FIG. 10B is a schematic cross-sectional illustration of the
heart showing access through the inter-atrial septum (IAS)
maintained by the placement of a guide catheter over a guidewire in
accordance with various embodiments of the present technology.
[0034] FIG. 11A is a cross-sectional top view of a prosthetic heart
valve repair device in an expanded configuration in accordance with
an embodiment of the present technology.
[0035] FIG. 11B is a cross-sectional side view of a prosthetic
heart valve repair device in an expanded configuration in
accordance with an embodiment of the present technology.
[0036] FIG. 11C is a cross-sectional side view of a prosthetic
heart valve repair device in a contracted configuration in
accordance with an embodiment of the present technology.
[0037] FIG. 12A is a cross-sectional top view of a prosthetic heart
valve repair device and a delivery system at a stage of implanting
the prosthetic heart repair valve device in accordance with an
embodiment of the present technology.
[0038] FIG. 12B is a cross-sectional top view of the prosthetic
heart valve repair device and delivery system of FIG. 12A at a
subsequent stage of implanting the prosthetic heart repair valve
device in accordance with an embodiment of the present
technology.
[0039] FIG. 13 is a cross-sectional view schematically illustrating
a left atrium, left ventricle, and native mitral valve of a heart
with an embodiment of a prosthetic heart valve repair device
implanted in the native mitral valve region in accordance with an
embodiment of the present technology.
[0040] FIG. 14 is a cross-sectional view schematically illustrating
a portion of a left atrium, left ventricle, and native mitral valve
of a heart with an embodiment of a prosthetic heart valve repair
device implanted in the native mitral valve region in accordance
with an embodiment of the present technology.
[0041] FIG. 15 is a cross-sectional view schematically illustrating
a portion of a left atrium, left ventricle, and native mitral valve
of a heart with an embodiment of a prosthetic heart valve repair
device implanted in the native mitral valve region in accordance
with an embodiment of the present technology.
[0042] FIGS. 16A and 16B are cross-sectional views schematically
illustrating a portion of a left atrium, left ventricle, and native
mitral valve of a heart with an embodiment of a prosthetic heart
valve repair device implanted in the native mitral valve region in
accordance with an embodiment of the present technology.
[0043] FIGS. 17A-17C are schematic top views of a native mitral
valve in the heart viewed from the left atrium and showing a heart
valve repair device implanted at the native mitral valve in
accordance with additional embodiments of the present
technology.
[0044] FIG. 18 is a perspective view of a prosthetic heart valve
repair device in an expanded configuration in accordance with
another embodiment of the present technology.
[0045] FIG. 19 is a cross-sectional view schematically illustrating
a left atrium, left ventricle, and native mitral valve of a heart
with a prosthetic heart valve repair device implanted in the native
mitral valve region in accordance with an embodiment of the present
technology.
[0046] FIG. 20A is a schematic top view of a native mitral valve in
the heart viewed from the left atrium and showing normal closure of
native mitral valve leaflets.
[0047] FIG. 20B is a schematic top view of a native mitral valve in
the heart viewed from the left atrium and showing abnormal closure
of native mitral valve leaflets, and which is suitable for
combination with various prosthetic heart valve repair devices in
accordance with embodiments of the present technology.
[0048] FIG. 20C is a schematic top view of a native mitral valve in
the heart viewed from the left atrium and showing a heart valve
repair device implanted at the native mitral valve in accordance
with an embodiment of the present technology.
[0049] FIG. 21A is a schematic top view of a native mitral valve in
the heart viewed from the left atrium and showing a heart valve
repair device implanted at the native mitral valve in accordance
with a further embodiment of the present technology.
[0050] FIG. 21B is a schematic top view of a native mitral valve in
the heart viewed from the left atrium and showing a heart valve
repair device implanted at the native mitral valve in accordance
with another embodiment of the present technology.
[0051] FIG. 21C is a schematic top view of a native mitral valve in
the heart viewed from the left atrium and showing the heart valve
repair device of FIG. 21A and a prosthetic heart valve implanted at
the native mitral valve in accordance with an embodiment of the
present technology.
[0052] FIG. 22 illustrates a method for repairing a native valve of
a patient in accordance with an embodiment of the present
technology.
DETAILED DESCRIPTION
[0053] Specific details of several embodiments of the technology
are described below with reference to FIGS. 1A-22. Although many of
the embodiments are described below with respect to devices,
systems, and methods for percutaneous repair of a native mitral
valve using prosthetic heart valve repair devices, other
applications and other embodiments in addition to those described
herein are within the scope of the technology. Additionally,
several other embodiments of the technology can have different
configurations, components, or procedures than those described
herein. A person of ordinary skill in the art, therefore, will
accordingly understand that the technology can have other
embodiments with additional elements, or the technology can have
other embodiments without several of the features shown and
described below with reference to FIGS. 1A-22.
[0054] With regard to the terms "distal" and "proximal" within this
description, unless otherwise specified, the terms can reference a
relative position of the portions of a heart valve repair device
and/or an associated delivery device with reference to an operator
and/or a location in the vasculature or heart. For example, in
referring to a delivery catheter suitable to deliver and position
various heart valve repair or replacement devices described herein,
"proximal" can refer to a position closer to the operator of the
device or an incision into the vasculature, and "distal" can refer
to a position that is more distant from the operator of the device
or further from the incision along the vasculature (e.g., the end
of the catheter). With respect to a prosthetic heart valve repair
or replacement device, the terms "proximal" and "distal" can refer
to the location of portions of the device with respect to the
direction of blood flow. For example, proximal can refer to an
upstream-oriented position or a position of blood inflow, and
distal can refer to a downstream-oriented position or a position of
blood outflow.
[0055] Additionally, the term "expanded configuration" refers to
the configuration or state of the device when allowed to freely
expand to an unrestrained size without the presence of constraining
or distorting forces. The terms "deployed configuration" or
"deployed" refer to the device after expansion at the native valve
site and subject to the constraining and distorting forces exerted
by the native anatomy. The terms "extended configuration" or
"extended state" refer to the "expanded configuration and/or
deployed configuration," and the terms "contracted configuration"
or "contracted state" refer to the device in a compressed or
otherwise collapsed state.
[0056] For ease of reference, throughout this disclosure identical
reference numbers and/or letters are used to identify similar or
analogous components or features, but the use of the same reference
number does not imply that the parts should be construed to be
identical. Indeed, in many examples described herein, the
identically numbered parts are distinct in structure and/or
function. The headings provided herein are for convenience
only.
Overview
[0057] Systems, devices and methods are provided herein for
percutaneous repair of native heart valves, such as mitral valves.
Several of the details set forth below are provided to describe the
following examples and methods in a manner sufficient to enable a
person skilled in the relevant art to practice, make and use them.
Several of the details and advantages described below, however, may
not be necessary to practice certain examples and methods of the
technology. Additionally, the technology may include other examples
and methods that are within the scope of the claims but are not
described in detail.
[0058] Embodiments of the present technology provide systems,
methods and apparatus to treat valves of the body, such as heart
valves including the mitral valve. The apparatus and methods enable
a percutaneous approach using a catheter delivered intravascularly
through a vein or artery into the heart. Additionally, the
apparatus and methods enable other less-invasive approaches
including trans-apical, trans-atrial, and direct aortic delivery of
a heart valve repair device to a target location in the heart. The
apparatus and methods enable a prosthetic device to be anchored at
or near a native valve location by engaging a subannular surface
and other sub-valvular elements of the valve annulus, chordae
tendineae, and/or valve leaflets. Additionally, the embodiments of
the devices and methods described herein can be combined with many
known surgeries and procedures, such as known methods of accessing
the valves of the heart (e.g., the mitral valve or tricuspid valve)
with antegrade or retrograde approaches, and combinations
thereof.
[0059] The devices and methods described herein provide a valve
repair device that has the flexibility to adapt and conform to the
variably-shaped native mitral valve anatomy while physically
supporting or bracing (e.g., pushing) the posterior leaflet of the
mitral valve toward the anterior leaflet in at least a partially
closed position to facilitate coaptation of the native mitral
leaflets during systole. Several embodiments of the device
effectively reduce the size of the mitral orifice and render the
native mitral valve competent. The device has the structural
strength and integrity necessary to withstand the dynamic
conditions of the heart over time and to permanently anchor the
repair device in the subannular position so that the patient can
resume a substantially normal life. The systems and methods further
deliver such a device in a less-invasive manner to provide a
patient with a new, permanent repair device using a lower-risk
procedure that has a faster recovery period compared to
conventional procedures.
[0060] Several embodiments of the present technology include
devices for repairing a native valve of a heart. Native heart
valves have an annulus and leaflets, and such repair devices
include a support for engaging an interior surface of a heart wall
and an outward-facing surface (e.g., a backside, underside or
downstream side) of a leaflet of the native valve in a subannular
position of the native valve. The device can be configured to
support the leaflet in an at least partially closed position. In
the at least partially closed position the leaflet can be
positioned so that valve function is improved, usually by improving
the coaptation of the leaflets. For example, in the at least
partially closed position the leaflet can be held closer to an
opposing leaflet of the native valve such that the two leaflets
coapt, or sealingly engage with one another, through a portion of
the cardiac cycle. The leaflet may be positioned so that a portion
of the leaflet--which may be the free edge of the leaflet or a
mid-portion of the leaflet--coapts with a surface of the opposing
leaflet with which the leaflet did not coapt prior to treatment.
The device can have a support that optionally can include a spine
or beam and an extension unit coupled to or extending from or
around the spine. In one embodiment, the extension unit can include
a biocompatible material suitable to support tissue ingrowth. In
various embodiments, the extension unit can include a plurality of
projections configured to expand or otherwise extend between and/or
engage chordae tendineae associated with the leaflet. In some
embodiments, the extension unit comprises a flexible,
fluid-impermeable cover, such as an inflatable bladder or balloon,
and an injectable filler material within the cover that expands
portions of the extension unit and maintains the expanded
configuration over time (e.g., filling and expanding the plurality
of projections).
[0061] Some embodiments of the disclosure are directed to systems
to repair a native valve of a patient and implant a prosthetic
valve. In one embodiment, the system can have a prosthetic heart
valve repair device implantable in a subannular position relative
to the native valve and having a support for engaging an interior
surface of a heart wall and an outward-facing surface (e.g., a
backside, underside or downstream side) of a leaflet of the native
valve in a subannular position of the native valve. In this
embodiment, the support can be configured to change an annulus
shape and/or an annulus cross-sectional dimension when the device
is in a deployed configuration. For example, the support can be
configured to change the annulus shape from a non-circular
cross-section to a more circular or substantially circular
cross-section. The system can also include a prosthetic heart
valve. The prosthetic heart valve can, for example, include a
radially expandable support structure with a lumen and a valve
coupled to the support structure in the lumen. In this arrangement,
when the prosthetic heart valve repair device is implanted in the
subannular position, the radially expandable support structure can
be supported within the changed annulus shape or changed annulus
cross-sectional dimension. In a particular example, the heart valve
repair device can be positioned behind a posterior mitral valve
leaflet in a subannular region, and the prosthetic heart valve can
have a substantially circular cross-sectional dimension.
[0062] Other aspects of the present technology are directed to
methods for repairing a native valve of a patient. In one
embodiment, a method includes positioning a heart valve repair
device in a subannular position behind at least one leaflet
connected to chordae tendineae. The repair device can have a
support that is initially in a contracted configuration. The method
can also include expanding or otherwise extending the support in
the subannular position such that the support engages an interior
surface of a heart wall and an outward-facing surface (e.g., a
backside, underside or downstream side) of the leaflet. In one
example, the native valve is a mitral valve and the support can
engage a left ventricular wall and a posterior mitral valve
leaflet. In exemplary embodiments the support is extended toward a
free edge of the leaflet, or toward an opposing leaflet with which
the supported leaflet should coapt. In embodiments for mitral valve
repair, the support may be extended in an anterior direction (i.e.,
away from a posterior wall of the ventricle and toward the anterior
leaflet), or toward the anterior edge of the posterior leaflet. In
various embodiments, the repair device is configured to support the
leaflet in at least a partially closed position to facilitate
coaptation of the valve leaflets and thereby repair the native
valve. This coaptation may occur at the distal free edges of one or
both leaflets, or along a middle portion of one or both
leaflets.
[0063] Another embodiment of the disclosure is directed to a heart
valve repair device to treat a native valve of a patient. In
various arrangements, the repair device can comprise a frame having
a first end configured to be placed at least proximate a first
commissure of the native valve and a second end configured to be
placed at least proximate a second commissure of the native valve.
The frame can further include a curved region between the first and
second ends. The curved region of the frame can be configured to
engage a backside of a leaflet of the native heart valve such that
the leaflet at least partially coapts with an adjacent leaflet of
the native valve.
[0064] The devices and methods disclosed herein can be configured
for treating non-circular, asymmetrically shaped valves and
bileaflet or bicuspid valves, such as the mitral valve. It can also
be configured for treating other valves of the heart such as the
tricuspid valve. Many of the devices and methods disclosed herein
can further provide for long-term (e.g., permanent) and reliable
anchoring of the prosthetic device even in conditions where the
heart or native valve may experience gradual enlargement or
distortion.
Cardiac and Mitral Valve Physiology
[0065] FIGS. 2 and 3 show a normal heart H. The heart comprises a
left atrium that receives oxygenated blood from the lungs via the
pulmonary veins PV and pumps this oxygenated blood through the
mitral valve MV into the left ventricle LV. The left ventricle LV
of a normal heart H in systole is illustrated in FIG. 3. The left
ventricle LV is contracting and blood flows outwardly through the
aortic valve AV in the direction of the arrows. Back flow of blood
or "regurgitation" through the mitral valve MV is prevented since
the mitral valve is configured as a "check valve" which prevents
back flow when pressure in the left ventricle is higher than that
in the left atrium LA. More specifically, the mitral valve MV
comprises a pair of leaflets having free edges FE which meet
evenly, or "coapt" to close, as illustrated in FIG. 3. The opposite
ends of the leaflets LF are attached to the surrounding heart
structure via an annular region of tissue referred to as the
annulus AN.
[0066] FIG. 4 is a schematic cross-sectional side view showing an
annulus and leaflets of a mitral valve in greater detail. As
illustrated, the opposite ends of the leaflets LF are attached to
the surrounding heart structure via a fibrous ring of dense
connective tissue referred to as the annulus AN, which is distinct
from both the leaflet tissue LF as well as the adjoining muscular
tissue of the heart wall. The leaflets LF and annulus AN are
comprised of different types of cardiac tissue having varying
strength, toughness, fibrosity, and flexibility. Furthermore, the
mitral valve MV may also comprise a unique region of tissue
interconnecting each leaflet LF to the annulus AN that is referred
to herein as leaflet/annulus connecting tissue LAC (indicated by
overlapping cross-hatching).
[0067] Referring back to FIG. 3, the free edges FE of the mitral
leaflets LF are secured to the lower portions of the left ventricle
LV through chordae tendineae CT which include a plurality of
branching tendons secured over the lower surfaces of each of the
valve leaflets LF. The primary chordae CT in turn, are attached to
the papillary muscles PM, which extend upwardly from the lower wall
of the left ventricle LV and interventricular septum IVS. Although
FIG. 3 shows the primary chordae tendineae (CT) which connect the
leaflets to the papillary muscles, the posterior leaflet of the
mitral valve (as well as the leaflets of the tricuspid valve) also
have secondary and tertiary chordae tendineae which connect the
leaflets directly to the ventricular wall. These secondary and
tertiary chordae tendineae have a range of lengths and positions,
connecting to the leaflets at all heights, including close to the
leaflets' connection to the valve annulus. The secondary and
tertiary chordae tendineae are illustrated in FIGS. 3, 5, 12,
13-16B and 19, and described in further detail herein.
[0068] Referring now to FIG. 5, regurgitation can occur in patients
suffering from functional mitral valve disease (e.g.,
cardiomyopathy) where the heart is dilated, and the increased size
prevents the valve leaflets LF from meeting properly. The
enlargement of the heart causes the mitral annulus to become
enlarged such that the free edges FE cannot meet (e.g., coapt)
during systole. The free edges FE of the anterior and posterior
leaflets normally meet along a line of coaptation C as shown in
FIG. 6A, a view of the top or left atrial side of the valve, but a
significant gap G can be left in patients suffering from
cardiomyopathy, as shown in FIG. 6B.
[0069] FIGS. 6A-6C further illustrates the shape and relative sizes
of the leaflets L of the mitral valve. As shown in FIG. 6C, the
overall mitral valve has a generally "D"-shape or kidney-like
shape, with a long axis MVA1 and a short axis MVA2. In healthy
humans the long axis MVA1 is typically within a range from about
33.3 mm to about 42.5 mm in length (37.9+/-4.6 mm), and the short
axis MVA2 is within a range from about 26.9 to about 38.1 mm in
length (32.5+/-5.6 mm). However, with patients having decreased
cardiac function these values can be larger, for example MVA1 can
be within a range from about 45 mm to 55 mm and MVA2 can be within
a range from about 35 mm to about 40 mm. The line of coaptation C
is curved or C-shaped such that the anterior leaflet AL is larger
than the posterior leaflet PL (FIG. 6A). Both leaflets appear
generally crescent-shaped from the superior or atrial side, with
the anterior leaflet AL being substantially wider in the middle of
the valve than the posterior leaflet PL. As illustrated in FIG. 6A,
at the opposing ends of the line of coaptation C, the leaflets join
together at corners called the anterolateral commissure AC and
posteromedial commissure PC.
[0070] FIG. 6C shows the shape and dimensions of the annulus of the
mitral valve. As described above, the annulus is an annular area
around the circumference of the valve comprised of fibrous tissue
which is thicker and tougher than that of the leaflets LF and
distinct from the muscular tissue of the ventricular and atrial
walls. The annulus may comprise a saddle-like shape with a first
peak portion PP1 and a second peak portion PP2 located along an
interpeak axis IPD, and a first valley portion VP1 and a second
valley portion VP2 located along an intervalley axis IVD. The first
and second peak portion PP1 and PP2 are higher in elevation
relative to a plane containing the nadirs of the two valley
portions VP1, VP2, typically being about 8-19 mm higher in humans,
thus giving the valve an overall saddle-like shape. The distance
between the first and second peak portions PP1, PP2, referred to as
interpeak span IPD, is substantially shorter than the intervalley
span IVD, the distance between first and second valley portions
VP1, VP2.
[0071] Referring back to FIG. 4, "subannular," as used herein,
refers to a portion of the mitral valve MV that lies on or
downstream DN of the plane PO of the native orifice. As used
herein, the plane PO of the native valve orifice is a plane
generally perpendicular to the direction of blood flow through the
valve and which contains either or both the major axis MVA1 or the
minor axis MVA2 (FIG. 6C). Thus, a subannular surface of the mitral
valve MV is a tissue surface lying on the ventricular side of the
plane PO, and preferably one that faces generally downstream,
toward the left ventricle LV. The subannular surface may be
disposed on the annulus AN itself or the ventricular wall behind
the native leaflets LF, or it may comprise an outward-facing or
downward-facing surface of the native leaflet OF, which lies below
the plane PO. The subannular surface or subannular tissue may thus
comprise the annulus AN itself, the outward-facing surface OF of
the native leaflets LF, leaflet/annulus connective tissue, the
ventricular wall or combinations thereof.
[0072] A person of ordinary skill in the art will recognize that
the dimensions and physiology of the mitral valves may vary among
patients, and although some patients may comprise differing
physiology, the teachings as described herein can be adapted for
use by many patients having various conditions, dimensions and
shapes of the mitral valve. For example, work in relation to
embodiments suggests that some patients may have a long dimension
across the annulus and a short dimension across the annulus without
well-defined peak and valley portions, and the methods and device
as described herein can be configured accordingly.
Access to the Mitral Valve
[0073] Access to the mitral valve or other atrioventricular valves
can be accomplished through the patient's vasculature in a
percutaneous manner. By percutaneous it is meant that a location of
the vasculature remote from the heart is accessed through the skin;
typically using a surgical cut down procedure or a minimally
invasive procedure, such as using needle access through, for
example, the Seldinger technique. The ability to percutaneously
access the remote vasculature is well-known and described in the
patent and medical literature. Depending on the point of vascular
access, the approach to the mitral valve may be antegrade and may
rely on entry into the left atrium by crossing the inter-atrial
septum. Alternatively, approach to the mitral valve can be
retrograde where the left ventricle is entered through the aortic
valve. Once percutaneous access is achieved, the interventional
tools and supporting catheter(s) may be advanced to the heart
intravascularly and positioned adjacent the target cardiac valve in
a variety of manners.
[0074] An example of a retrograde approach to the mitral valve is
illustrated in FIGS. 7 and 8. The mitral valve MV may be accessed
by an approach from the aortic arch AA, across the aortic valve AV,
and into the left ventricle LV below the mitral valve MV. The
aortic arch AA may be accessed through a conventional femoral
artery access route, as well as through more direct approaches via
the brachial artery, axillary artery, radial artery, or carotid
artery. Such access may be achieved with the use of a guidewire 6.
Once in place, a guide catheter 4 may be tracked over the guidewire
6. Alternatively, a surgical approach may be taken through an
incision in the chest, preferably intercostally without removing
ribs, and placing a guide catheter through a puncture in the aorta
itself. The guide catheter 4 affords subsequent access to permit
placement of the prosthetic valve device, as described in more
detail herein.
[0075] In some specific instances, a retrograde arterial approach
to the mitral valve may be selected due to certain advantages. For
example, use of the retrograde approach can eliminate the need for
a trans-septal puncture (described below). The retrograde approach
is also more commonly used by cardiologists and thus has the
advantage of familiarity.
[0076] An additional approach to the mitral valve is via
trans-apical puncture, as shown in FIG. 9. In this approach, access
to the heart is gained via thoracic incision, which can be a
conventional open thoracotomy or sternotomy, or a smaller
intercostal or sub-xyphoid incision or puncture. An access cannula
is then placed through a puncture in the wall of the left ventricle
at or near the apex of the heart and then sealed by a purse-string
suture. The catheters and prosthetic devices of the invention may
then be introduced into the left ventricle through this access
cannula.
[0077] The trans-apical approach has the feature of providing a
shorter, straighter, and more direct path to the mitral or aortic
valve. Further, because it does not involve intravascular access,
the trans-apical procedure can be performed by surgeons who may not
have the necessary training in interventional cardiology to perform
the catheterizations required in other percutaneous approaches.
[0078] Using a trans-septal approach, access is obtained via the
inferior vena cava IVC or superior vena cava SVC, through the right
atrium RA, across the inter-atrial septum IAS and into the left
atrium LA above the mitral valve MV.
[0079] As shown in FIG. 10A, a catheter 1 having a needle 2 may be
advanced from the inferior vena cava IVC into the right atrium RA.
Once the catheter 1 reaches the anterior side of the inter-atrial
septum IAS, the needle 2 may be advanced so that it penetrates
through the septum, for example at the fossa ovalis FO or the
foramen ovale into the left atrium LA. The catheter is then
advanced into the left atrium over the needle. At this point, a
guidewire may be exchanged for the needle 2 and the catheter 1
withdrawn.
[0080] As shown in FIG. 10B, access through the inter-atrial septum
IAS may usually be maintained by the placement of a guide catheter
4, typically over a guidewire 6 which has been placed as described
above. The guide catheter 4 affords subsequent access to permit
introduction of the device to repair the mitral valve, as described
in more detail herein.
[0081] In an alternative antegrade approach (not shown), surgical
access may be obtained through an intercostal incision, preferably
without removing ribs, and a small puncture or incision may be made
in the left atrial wall. A guide catheter may then be placed
through this puncture or incision directly into the left atrium,
sealed by a purse string-suture.
[0082] The antegrade or trans-septal approach to the mitral valve,
as described above, can be advantageous. For example, the antegrade
approach may decrease risks associated with crossing the aortic
valve as in retrograde approaches. This can be particularly
relevant to patients with prosthetic aortic valves, which may not
be crossed at all or without substantial risk of damage.
[0083] The prosthetic valve repair device may also be implanted
using conventional open-surgical approaches. For some patients, the
devices and methods of the invention may offer a therapy better
suited for the treatment of certain valve pathologies or more
durable than existing treatments such as annuloplasty or valve
replacement.
[0084] The prosthetic valve repair device may be specifically
designed for the approach or interchangeable among approaches. A
person of ordinary skill in the art can identify an appropriate
approach for an individual patient and design the treatment
apparatus for the identified approach in accordance with
embodiments described herein.
[0085] Orientation and steering of the prosthetic valve repair
device can be combined with many known catheters, tools and
devices. Such orientation may be accomplished by gross steering of
the device to the desired location and then refined steering of the
device components to achieve a desired result.
[0086] Gross steering may be accomplished by a number of methods. A
steerable guidewire may be used to introduce a guide catheter and
the prosthetic valve repair device into the proper position. The
guide catheter may be introduced, for example, using a surgical cut
down or Seldinger access to the femoral artery in the patient's
groin. After placing a guidewire, the guide catheter may be
introduced over the guidewire to the desired position.
Alternatively, a shorter and differently shaped guide catheter
could be introduced through the other routes described above.
[0087] A guide catheter may be pre-shaped to provide a desired
orientation relative to the mitral valve. For access via the
trans-septal approach, the guide catheter may have a curved, angled
or other suitable shape at its tip to orient the distal end toward
the mitral valve from the location of the septal puncture through
which the guide catheter extends. For the retrograde approach, as
shown in FIGS. 7 and 8, guide catheter 4 may have a pre-shaped
J-tip which is configured so that it turns toward the mitral valve
MV after it is placed over the aortic arch AA and through the
aortic valve AV. As shown in FIG. 7, the guide catheter 4 may be
configured to extend down into the left ventricle LV and to assume
a J-shaped configuration so that the orientation of an
interventional tool or catheter is more closely aligned with the
axis of the mitral valve MV. As shown in FIG. 8, the guide catheter
might alternatively be shaped in a manner suitable to advance
behind the posterior leaflet. In either case, a pre-shaped guide
catheter may be configured to be straightened for endovascular
delivery by means of a stylet or stiff guidewire which is passed
through a lumen of the guide catheter. The guide catheter might
also have pull-wires or other means to adjust its shape for more
fine steering adjustment.
Selected Embodiments of Prosthetic Heart Valve Repair Devices and
Methods
[0088] Embodiments of the present technology can be used to treat
one or more of the valves of the heart as described herein, and
several embodiments are well suited for treating the mitral valve.
Introductory examples of prosthetic heart valve repair devices,
system components, and associated methods in accordance with
embodiments of the present technology are described in this section
with reference to FIGS. 11A-22. It will be appreciated that
specific elements, substructures, advantages, uses, and/or other
features of the embodiments described with reference to FIGS.
11A-22 can be suitably interchanged, substituted or otherwise
configured with one another. Furthermore, suitable elements of the
embodiments described with reference to FIGS. 11A-22 can be used as
stand-alone and/or self-contained devices.
[0089] Systems, devices and methods in accordance with the present
technology provide percutaneous implantation of prosthetic heart
valve repair devices in a heart of a patient. In some embodiments,
methods and devices treat valve diseases by minimally invasive
implantation of repair devices behind one or more native leaflets
in a subannular position using the techniques described above with
respect to FIGS. 7-10B. In one embodiment, the repair device can be
suitable for engaging an interior surface of a heart wall, such as
a left ventricular wall, and a backside of a leaflet (e.g., the
posterior leaflet of a mitral valve in the heart of a patient). In
another embodiment, the repair device can be suitable for
implantation and repair of another valve in the heart of the
patient (e.g., a bicuspid or tricuspid valve).
[0090] FIG. 11A is a cross-sectional top view showing a prosthetic
heart valve repair device 100 ("repair device 100") in an expanded
or extended configuration in accordance with an embodiment of the
present technology, and FIGS. 11B and 11C are cross-sectional side
views showing the repair device 100 in the expanded configuration
and a contracted or delivery configuration, respectively. The
repair device 100 can be movable between the delivery configuration
shown in FIG. 11C and the expanded configuration shown in FIGS.
11A-B to be deployed under the posterior leaflet of the mitral
valve. In the delivery configuration shown in FIG. 11C, the repair
device 100 has a low profile suitable for delivery through a lumen
102 of a small-diameter catheter 104 positioned in the heart via
the trans-septal, retrograde, or trans-apical approaches described
herein. In some embodiments, the delivery configuration of the
repair device 100 will preferably have an outer diameter as small
as possible, such as no larger than about 8-10 mm for trans-septal
approaches, about 6-8 mm for retrograde approaches, or about 8-12
mm for trans-apical approaches to the mitral valve MV. In some
embodiments, the repair device 100 can be resilient and relatively
resistant to compression once deployed, making it easier to
position and retain the device in the target location. As seen in
FIG. 11A, repair device 100 may be preformed to assume a curved
shape or other non-straight shape when unconstrained in the
deployed configuration. Accordingly, repair device 100 may be
flexible and resilient so that it may be formed in a more linear
shape when positioned in lumen 102 of catheter 104 and it will
resiliently return to its preformed deployed configuration when
released from the catheter. Alternatively or additionally, repair
device 100 may be inflatable or fillable with a fluid material as
further described below, and it may be configured to assume a
predetermined deployed shape as a result of fluid pressure.
[0091] In the embodiment shown in FIG. 11A, the repair device 100
includes a support 110 for engaging and at least partially
conforming to a subannular position between an interior surface of
a heart chamber wall (e.g., a left ventricle wall) and a backside
of a native valve leaflet (e.g., the mitral valve posterior
leaflet). The support 110 can generally have a first end 112, a
second end 114, and curved region 116 between the first and second
ends 112, 114. In one embodiment, the support 110 can be positioned
as close as possible to the valve annulus in the subannular region
(e.g., at the highest point in the space between the outside-facing
surface of the valve leaflet and the ventricular wall). The curved
shape of the curved region 116 may accommodate and/or otherwise
conform to the curved shape of the posterior mitral annulus, or it
may be relatively stiff to encourage a specific shape. The length
of the support 110 can extend substantially the entire distance
between the commissures, or only part way around the posterior
leaflet PL without reaching the commissures, or beyond one or both
commissures so as to extend below a portion of the anterior leaflet
AL. The support 110 is preferably configured to be wedged or
retained by compression or friction with the underside (e.g., the
outward-facing surface or downstream side) of the posterior leaflet
PL and the inner wall of the ventricle, and/or engagement with the
chordae tendineae attached to the posterior leaflet PL. In some
embodiments the support 110 is configured to be positioned between
the basal and/or tertiary chordae tendineae and the ventricular
wall. The support 110 will preferably be sufficiently rigid to
deflect the posterior leaflet PL to the desired post-treatment
configuration, but still having some flexibility to allow it to
flex and avoid tissue damage under high forces. The support 110 may
also have some resilience and compressibility to remain engaged
with the chordae tendineae, the leaflet and the wall tissue as the
heart changes shape both acutely and long-term. The support can be
a frame, bladder, balloon, foam, tube (e.g., a mesh tube), or other
structure that is configured to extend (e.g., expand) at a target
site in a manner that pushes or otherwise repositions a leaflet of
a native valve from a pre-treatment position in which the native
leaflets fail to coapt properly to a post-treatment position in
which the leaflets coapt during a portion of the cardiac cycle. The
support can be further configured to brace, support, or otherwise
maintain the leaflet in the post-treatment position for at least a
portion of the cardiac cycle, preferably permanently.
[0092] The support 110 can be pre-shaped such that upon deployment,
the repair device 100 accommodates (e.g., approximates) the shape
of the native anatomy or the desired post-treatment shape of the
native anatomy. For example, the support 110 can be pre-shaped to
expand into a "C" shape or other suitably curved shape to
accommodate the curvature of the mitral valve annulus and/or to
conform to a portion of the native mitral valve annulus. In some
embodiments, several components of the support 110 can have a
subannular engaging surface 118 that includes one or more peaks
(not shown) and one or more valleys (not shown) in the
upstream-downstream direction for accommodating or conforming to
the native saddle-shape contour of the mitral annulus. An outer
edge 117 of the curved region 116 of the support 110 can be
positionable against the interior surface of the heart wall.
[0093] Referring to FIGS. 11A and 11B together, the support 110 can
include a central spine 111 (e.g., a beam, a tube, or a frame) that
may be a stent structure, such as a balloon-expandable or
self-expanding stent. In other embodiments, the spine 111 can be a
coiled spring, a braided tube, a wire, a polymeric member, or other
form. The spine 111 and/or other portions of the support 110, in
various embodiments, can include metal material such as
nickel-titanium alloys (e.g. nitinol), stainless steel, or alloys
of cobalt-chrome. In other embodiments, the support 110 can include
a polymer such as Dacron.RTM., polyester, polypropylene, nylon,
Teflon.RTM., PTFE, ePTFE, etc. Other suitable materials known in
the art of elastic and/or expandable or flexible implants may be
also be used to form some components of the support 110. As shown
in FIG. 11A, several embodiments of the spine 111 can be formed, at
least in part, from a cylindrical braid or stent structure
comprising elastic filaments. Accordingly, the spine 111 and/or
other portions of the support 110 can include an elastic,
superelastic or other shape memory component that self-expands upon
deployment of the device 100 to a formed or a pre-formed
configuration at a target site. The spine 111 can further include a
lumen 119 through which a guidewire (not shown) and/or
strengthening/stiffening elements 115 (shown in FIG. 11B), such as
wires, coils, or polymeric elements, can be placed into or
integrated within the support 110. Such strengthening/stiffening
elements 115 can be inserted into the lumen 119 before or during
deployment of the repair device 100 to provide additional resistive
pressure against the cardiac tissue once implanted. Spine 111 can
be flexible and resilient so it can be straightened for delivery in
a catheter or sheath or over a wire, and it can resiliently return
to a curved shape (e.g., a curved shape similar to the native valve
annulus) when unconstrained. In some embodiments, the spine 111
preferably has sufficient stiffness to structurally support the
treated valve leaflet in the desired position and shape. In some
embodiments, spine 111 may be covered with a biocompatible,
flexible fabric or polymer, preferably one that allows tissue
ingrowth.
[0094] The support 110 can further include an extension unit 120
attached to and/or positioned around at least a portion of the
spine 111. In one embodiment, for example, the extension unit 120
can be biocompatible with cardiac tissue at or near the native
valve of the patient so as to promote tissue ingrowth and
strengthen implantation of the repair device 100 within the native
valve region. In exemplary embodiments, extension unit 120 can
comprise a flexible cover of biocompatible fabric or polymer that
surrounds spine 111. In one embodiment, the extension unit 120 can
include an expandable member, such as an expandable tube, balloon,
bladder, foam or other expandable material, that is coupled to the
spine 111. The expandable member may itself surround spine 111, may
be held within a flexible fabric or polymeric cover extending
around or attached to spine 111, or may be attached directly to a
lateral side of spine 111. For example, the extension unit 120 can
be an elastic or inelastic balloon made from impermeable, flexible
biocompatible materials. The extension unit 120 can comprise a
fabric or other flexible, stretchable and/or biocompatible material
such as braided, woven, or crocheted Dacron.RTM., expanded PTFE
(Gore-Tex.RTM.), bovine pericardium, or other suitable flexible
material to integrate with adjacent tissue and promote tissue
ingrowth to facilitate further stability of the repair device 100
in the subannular position. In other embodiments, the extension
unit 120 can include polyester fabric, a polymer, thermoplastic
polymer, a synthetic fiber, a natural fiber or polyethylene
terephthalate (PET). Several embodiments of the extension unit 120
may be pre-shaped to accommodate a relatively fixed maximal
dimension and shape when the repair device 100 is implanted. In
various embodiments, the extension unit 120 can be porous and/or
adhere to the interior surface of the heart wall and/or the
backside of the leaflet. Tissue ingrowth into the extension unit
120 can form a pannus of tissue which is hemocompatible and can
strengthen the combined structure of the repair device 100, the
subannular tissue and/or interior surface of the heart wall, and
the backside of the leaflet. Extension unit 120 will be expandable
(e.g., in a transverse or radial direction relative to the
longitudinal axis of the spine 111) from a collapsed configuration
for endovascular or trans-apical delivery to an expanded
configuration suitable for bracing the valve leaflet in the desired
position. Extension unit 120 will usually be more flexible than
spine 111 when in an unexpanded configuration, and in some
embodiments will become substantially more rigid when expanded,
e.g. by filling or inflating with a fluid. This rigidity may be
imparted solely by fluid pressure, or by hardening or curing the
fluid (e.g. epoxy or cement) within the extension unit.
[0095] The support 110 can further include a plurality of
projections 130 and depressions 131 in the expanded configuration.
The projections 130 alternate with depressions 131 such that each
depression is disposed between two projections, forming a series of
peaks and valleys. For example, the projections 130 can be features
of the extension unit 120 that extend toward the other native
leaflet and generally parallel to the underside of the supported
leaflet such that the projections 130 extend between and engage the
secondary and/or tertiary chordae tendineae that tether the leaflet
(e.g., the mitral valve posterior leaflet) to the ventricular wall.
In some embodiments all or a portion of the projections 130 may
extend in generally the same (anterior) direction, while in other
embodiments the projections 130 may extend in a radially inward
direction relative to the curvature of the spine 111 (or native
valve annulus). As such, a portion of the secondary and/or tertiary
chordae tendineae can be positioned in the depressions 131 after
the repair device 100 has been deployed. The upper or
leaflet-facing sides of the projections 130 are preferably smooth
and wide enough to support the leaflet without abrading or damaging
the leaflet should it move or rub against the projections during
the cardiac cycle. The depressions 131 are preferably wide enough
to receive at least one of the chordae somewhat snugly to inhibit
lateral movement of the support.
[0096] Referring still to FIGS. 11A-B and in accordance with an
embodiment of the present technology, the extension unit 120 can
include a plurality of pockets 132 that can be configured to
receive filler material 140 during or upon deployment of the device
100 to form the projections 130. For example, a liquid that cures
into a permanently semi-flexible or rigid material can be injected
into the extension unit 120 to at least partially fill the pockets
132 of the extension unit 120 and thereby form the projections 130.
In other embodiments, not shown, the pockets 132 can be expanded to
form the projections 130 using internal elements such as segmented
stents, one or more coiled spring elements, or other reinforcement
structures. For example, the stent or spring might be pre-shaped to
help the device 100 assume the deployed configuration (e.g., shape
and profile). Accordingly, once in the deployed configuration, the
projections 130 can be interspersed between the chordae tendineae
CT.
[0097] The side of the support opposite the projections 130 (i.e.,
posterior side in mitral embodiments) will preferably be configured
to atraumatically and compressively engage the ventricular wall to
assist in anchoring the device in place. The posterior surface may
be a soft, compressive, and resilient material, preferably
atraumatic to the heart wall, and preferably one that encourages
tissue in-growth. In some embodiments, the posterior side may have
retention elements, e.g. spikes, hooks, bristles, points, bumps, or
ribs, protruding from its surface, to engage the ventricular wall
to further assist in anchoring and immobilizing the device. The
posterior side may also have one or more expandable, resilient, or
spring-like elements thereon that engage the ventricular wall and
urge the support 110 in the anterior direction (away from the wall)
to firmly and compressively engage the chordae tendonae between the
projections 130. This can supplement or substitute for the
expansion of the support 110 or extension member.
[0098] FIGS. 12A and 12 B are cross-sectional top views of the
repair device 100 and a delivery system at stages of implanting the
repair device 100 (spine 111 removed for clarity in FIG. 12A) in
accordance with an embodiment of the present technology. Referring
to FIG. 12A, a guidewire GW is positioned at the implant site and a
guide catheter 1210 is passed over the guidewire GW until the guide
catheter 1210 is positioned at least proximate the valve. An
optional delivery catheter or sheath 1220 can then be passed
through the guide catheter 1210. The guidewire GW can be withdrawn,
and the repair device 100 is then passed through the guide catheter
1210 or the optional sheath 1220. In another embodiment, the
guidewire GW is received in the lumen 119 (FIGS. 11A and 11B) of
the repair device 100 such that the repair device 100 passes over
the guidewire GW during implantation. When the repair device 100 is
used to repair a native mitral valve MV, the guidewire GW can be
positioned under the posterior leaflet PL of the native mitral
valve MV, the guide catheter 1210 and/or optional sheath 1220 are
then placed at a target site under the posterior leaflet PL, and
then the repair device 100 is positioned within the guide catheter
1210 and/or the optional sheath 1220 at the target site. At this
stage, the anterior and posterior leaflets fail to coapt, resulting
in a gap G between the posterior leaflet PL and the anterior
leaflet AL.
[0099] FIG. 12B shows a subsequent stage of implanting the repair
device 100 under the posterior leaflet PL of the native mitral
valve MV. The sheath 1220 can have a lumen 1222, and the repair
device 100 can be attached to a shaft 1230 by a release mechanism
1232. Additionally, an inflation tube 1240 can extend along or
through the sheath 1220 and through a one-way valve (not shown)
into the extension unit 120 of the support 110. In one embodiment,
the repair device 100 is contained in a radially collapsed state in
the lumen 1222 of the sheath 1220 as the repair device 100 is
positioned under the posterior leaflet PL, and then the sheath 1220
is retracted proximally to expose the repair device 100 at the
target site. After the repair device 100 has been exposed, the
filler material 140 is injected into the extension unit 120 via the
inflation tube 1240 causing the projections 130 to extend away from
the spine 111 towards the central axis of the valve orifice (arrows
AD). The projections 130 accordingly push at least the free edge of
the posterior leaflet PL toward the anterior leaflet AL until the
gap G (FIG. 12A) at least partially closes to enhance the
competency of the native mitral valve MV. In the embodiment shown
in FIG. 12B, the gap G is completely eliminated such that the free
edge of the posterior leaflet PL fully coapts with the free edge of
the anterior leaflet AL. Additionally, the chordae tendineae CT
positioned in the depressions 131 between the projections 130
secure the repair device 100 in the subannular space. The release
mechanism 1232 is then activated to separate the repair device 100
from the shaft 1230. The sheath 1220 along with the shaft 1230 and
inflation tube 1240 are then withdrawn from the patient.
[0100] In other embodiments, the repair device 100 may include a
fluid absorbing material that expands after implantation by
absorption of blood or other fluids to inflate the extension unit
120 either in addition to or in lieu of using the inflation tube
1240. For example, the extension unit 120 may have a fluid
permeable cover and an absorbent material within the cover that
expands as it absorbs fluid, or the extension unit 120 can be a
foam that expands to form the projections 130. Alternatively, the
extension unit 120 may be filled with a fluid absorbing substance
such as a biocompatible hydrogel which expands when exposed to
blood or other fluid. In this way, the support 110 may be implanted
and optionally expanded partially, then allowed to expand to its
fully expanded configuration by absorption of fluids.
Alternatively, the extension unit 120 may be sufficiently porous to
allow blood to pass into it such that blood will collect and fill
up the extension unit. Eventually, the blood may clot and be
replaced by tissue to strengthen and rigidify the repair device
100. In further embodiments, the extension unit 120 may be
configured to receive an injectable material to realize a
fully-expanded configuration.
[0101] FIG. 13 is a cross-sectional view schematically illustrating
a left atrium, left ventricle, and native mitral valve of a heart
with an embodiment of the repair device 100 implanted in the native
mitral valve region. In this embodiment, the repair device 100 is
implanted in a subannular position and behind the posterior leaflet
PL of the native mitral valve MV at the ventricular side of the
mitral annulus AN as described above with reference to FIGS. 12A
and 12B. The repair device 100, for example, can have a ventricular
wall engaging surface 150 that engages the ventricular wall along a
distance DV and a posterior leaflet engaging surface 160 configured
to engage the outward-facing surface (e.g., underside or downstream
side) of the posterior leaflet PL. The repair device 100 is
retained in this subannular position by the chordae tendineae CT
(e.g., the basal or tertiary chordae tendineae which are associated
with the posterior leaflet PL closest to the annulus AN). As repair
device 100 is expanded from a collapsed, delivery configuration to
an expanded, deployed configuration, the width or area of the
posterior leaflet engaging surface 160 enlarges. In some
embodiments, repair device 100 can be expanded until the posterior
leaflet engaging surface has the desired width or area, e.g., until
the posterior leaflet is repositioned and/or reshaped such that it
coapts with the anterior leaflet and regurgitation through the
valve is reduced or eliminated. As shown in FIG. 13, when the
device 100 is in the deployed configuration, the posterior leaflet
engaging surface 160 engages the outward-facing surface (e.g.,
underside) of at least the posterior leaflet PL along a distance DL
from the posterior wall of the ventricle toward the anterior
leaflet AL to push, brace or otherwise support the posterior
leaflet PL such that it coapts with the anterior leaflet AL and/or
otherwise reduces mitral valve regurgitation (e.g., drives the
posterior leaflet PL toward the anterior leaflet AL into at least a
partially closed position). The distance DL can be selected or
controlled to adapt the repair device 100 to the specific anatomy
of the patient. In several embodiments, the distance DL is from
about 2-20 mm, preferably at least about 8 mm, or in other
embodiments from about 8 to about 12 mm. In some embodiments, the
device 100 can support the posterior leaflet PL in a fully closed
position, and in further embodiments the repair device 100 can
extend the posterior leaflet PL toward the anterior leaflet to a
closed position that extends beyond the leaflet's naturally closed
position. For example, the shape of the posterior leaflet PL may be
changed by expanding the repair device 100 to push it toward or
bracing it in a position closer to the anterior leaflet AL. In one
example, the repair device 100 can have a triangular or polygonal
cross-section for engaging the ventricular wall, the annulus AN,
and the outward-facing surface of the posterior leaflet PL. In
other embodiments, the repair device 100 can have a circular, oval,
elliptical, or oblong cross-section.
[0102] The overall cross-sectional shape of the repair device 100
can determine the resting location of the posterior leaflet PL as
it is braced in the at least partially closed position. Therefore,
the distances DV and DL, and the curvatures of the ventricular wall
engaging surface 150 and the posterior leaflet engaging surface
160, can be configured to accommodate different anatomical
requirements of different patients. For example, FIG. 14 shows
another embodiment of a repair device 100a similar to the repair
device 100 illustrated in FIG. 13, but in the deployed
configuration the repair device 100a includes a ventricular wall
engaging surface 150a with a vertical or cranial-caudal distance
DVa that is less than the corresponding distance DV of the
ventricular wall engaging surface 150 of the repair device 100
shown in FIG. 13. The repair device 100a further includes a
posterior leaflet engaging surface 160a that contacts the underside
of the posterior leaflet PL along posterior-anterior dimension by a
distance DLa greater than that of the posterior engaging surface
160 of the repair device 100 of FIG. 13. As such, the repair device
100a is able to support the posterior leaflet PL in a position
closer to the anterior leaflet AL than the device 100; the repair
device 100, more specifically, can move the line along which
posterior leaflet PL hinges to open and close away from the
posterior heart wall of the left ventricle and closer to the
anterior leaflet AL to reduce the size of the movable portion of
the posterior leaflet that opens and closes during the cardiac
cycle. The leaflet hinge may alternatively be eliminated altogether
so that the leaflet is substantially stationary throughout the
cardiac cycle.
[0103] FIG. 15 is a cross-sectional side view of a repair device
100b in accordance with another embodiment of the present
technology. The repair device 100b shown in FIG. 15 is similar to
the repair device 100a shown in FIG. 14, but the repair device 100b
in the deployed configuration is flatter (shorter in the
atrial-ventricular direction) than the repair device 100a. For
example, the repair device 100b has a ventricular wall engaging
surface 150b that engages the ventricular wall along a distance DVb
that is less than the distance DVa of the repair device 100a. The
repair device 100b may be easier to implant than the repair device
100a because the lower profile of the repair device 100b can fit in
a smaller delivery catheter and in the tight spaces between the
ventricular heart wall and the chordae tendineae CT.
[0104] FIGS. 16A and 16B are cross-sectional side views of a repair
device 100c in accordance with another embodiment of the present
technology. In this embodiment, the repair device 100c has an
extension unit 1620 including a bellows 1622 that preferentially
expands in the anterior direction AD. The bellows 1622 can be an
accordion style portion of the extension unit 1620, and the
remainder of the extension unit 1620 can be a flexible fabric or
polymeric material that is made from the same material as the
bellows 1622 or a different material. In other embodiments, the
portion of the extension unit 1620 other than the bellows 1622 can
be made from a metal or other material that can flex at a lower
bend 1624. In operation, as the extension unit 1620 is inflated,
the bellows 1622 allows the projection 130 to move in the anterior
direction AD such that the repair device 100c engages the underside
of the posterior leaflet PL by an increasing distance (e.g., DLc1
in FIG. 16A to DLc2 in FIG. 16B).
[0105] FIGS. 17A-17C are schematic top views of a native mitral
valve MV in the heart viewed from the left atrium and showing an
embodiment of any of the repair devices 100-100c described above
implanted at the native mitral valve MV in accordance with
additional embodiments of the present technology (repair devices
100-100c are identified collectively as "repair device 100" and
shown in dotted lines with respect to FIGS. 17A-17C). The presence
of the projections 130 may allow the repair device 100 to expand
fully for supporting or bracing the outward-facing surface of the
posterior leaflet PL in at least a partially closed position
without tearing or excessively displacing or stretching the chordae
tendineae which retain the repair device 100 at the target
implantation location. In some embodiments, the chordae tendineae
also help retain the repair device 100 in a desired cross-sectional
shape. The projections 130 may be configured to extend anteriorly
or radially along the underside of posterior leaflet PL through
gaps between the basal or tertiary chordae by a sufficient distance
to brace the posterior leaflet PL in the desired position for
effective coaptation. The distal tips of the projections 130 are
preferably rounded and smooth to avoid trauma to the leaflet and to
allow the leaflet to bend or fold around the projections 130 in the
partially closed position. The projections 130 may also have
structures, materials, or coatings thereon to engage and retain the
chordae tendineae such that the projections 130 will not pull out
in the reverse direction. For example, the projections 130 may have
an enlarged head or T-shape at their distal ends, scales or
backward-pointing tines along their sidewalls, or other features
that allow the projections 130 to slide easily between the chordae
tendineae in one direction but to resist movement in the other. The
projections 130 may also be coated with a tissue in-growth
promoting agent. In some embodiments, the device 100 can include
other materials that encourages tissue ingrowth and/or tissue
healing around the device such that the depressions 131 between the
projections 130 may be filled with tissue (e.g., pannus of tissue)
leaving a relatively smooth surface exposed to the left
ventricle.
[0106] As shown in FIG. 17A, the repair device 100 can have a
relatively consistent cross-sectional dimension over the length of
the device (e.g., at the first and second ends 112, 114 and along
the curved region 116). In a different embodiment shown in FIG.
17B, the curved region 116 device 100 can have a cross-sectional
dimension D1 that is larger than cross-sectional dimensions D2, D3
at the first and second ends 112, 114, respectively. In this
embodiment, the larger cross-sectional dimension D1 may assist the
coaptation of the posterior leaflet PL with the anterior leaflet AL
in the central region CR of the native mitral valve MV. In other
embodiments, the device 100 can be configured to have larger
cross-sectional dimensions at one or more ends (e.g., first and/or
second ends 112, 114). For example, FIG. 17C shows a repair device
100 having an asymmetric cross-section profile. As shown in FIG.
17C, the repair device can have a second end 114 having a
cross-sectional dimension D4 that is larger than cross-sectional
dimensions D5 and D6 of the curved region 116 and the first end
112, respectively. Accordingly, the repair device 100 can include a
variety of dimensions (e.g., cross-sectional dimensions) and shapes
that can be used to address a specific heart valve morphology of a
patient. For example, the device 100 could be shaped and sized to
repair areas of regurgitation within the native valve while
preserving functionality of the leaflets (e.g., posterior leaflet
function) to the extent possible in healthy areas of the native
valve. In alternative embodiments, the device 100 may have a
plurality of expandable, inflatable, or fillable regions or pockets
arranged along the length of the device which can be independently
expanded by injection of fluid to create regions of different
cross-sectional size or shape along the length of device 100. In
some embodiments, each of these regions or pockets could be
selectively expanded as the heart continues to beat until the
posterior leaflet is positioned and shaped as needed to reduce or
eliminate regurgitation through the valve.
[0107] Repair devices in accordance with any of the foregoing
embodiments can have other shapes, dimensions, sizes and
configurations to address patient specific anatomy or to otherwise
achieve coaptation of the native valve leaflets in a specific
patient. The shape and dimension of the repair device 100 may be
selected such that the posterior leaflet is braced in a position
which results in sealing coaptation of the posterior and anterior
leaflets during systole. The repair device 100 may be adjustable in
size or shape before or after placement to allow the physician to
adjust the device to achieve the desired post-treatment leaflet
position. For example, the repair device 100 may have malleable
portions that can be manually shaped by the physician, mechanically
articulating portions that can be remotely adjusted, or inflatable
portions into which a fluid may be injected to change their shape
or size.
[0108] One aspect of several embodiments of the repair devices
100-100c described above is that the support 110 is secured at the
target site without anchors or other components that pierce the
tissue of the leaflets, annulus and/or the wall of the heart. For
example, the combination of expanding or otherwise extending the
projections 130 between the chordae tendineae and pressing the
support 110 against the underside of the posterior leaflet and the
wall of the left ventricle securely holds the repair device in
place. This is expected to simplify the treatment and reduce trauma
to the heart.
[0109] In other embodiments, repair device 100 may have features on
its exterior to enhance fixation with the native tissue. For
example, the posterior surface that engages the wall of the
ventricle, and/or the upper surface that engages the posterior
leaflet, may have barbs, bumps, ribs, spikes, or other projections
configured to engage the tissue and enhance fixation through
friction or by penetration of the tissue surface. Additionally or
alternatively, friction-enhancing fabrics, polymers or other
materials may be provided on these surfaces. In other embodiments,
loops or hooks may be coupled to repair device 100 which are
configured to engage with or extend around the chordae or papillary
muscles. Further, the material used to cover repair device 100 may
enhance tissue ingrowth such that the device is encapsulated in
tissue within a short time after implantation.
[0110] Another aspect of several embodiments of the repair devices
100-100c is that the degree to which the projections 130 of the
extension unit 120 extend in an anterior direction can be
controlled to custom tailor the repair device 100 to the anatomy of
a specific patient. For example, when the extension unit 120 is an
inflatable bladder or balloon, the distance that the projections
130 extend in the anterior direction can be controlled by the
amount of filler material 140 that is injected into the extension
unit 120. This is expected to provide enhanced flexibility and
customization of the repair device 100.
[0111] FIG. 18 is a perspective view of another embodiment of a
repair device 1800 having a curved support 1810 with a first end
1812 and a second end 1814. The support 1810 may be similar to or
the same as any of the supports 110 described above. The repair
device 1800 further includes retention elements 1890 projecting
from the support 1810 to enhance anchoring to the native tissue.
Each retention member can have a post 1892 configured to extend
through the opening between the valve leaflets and a cross-member
1894 configured rest on a upstream side or exterior surface of the
valve leaflets. The retention elements 1890 may have a T-shape as
shown in FIG. 18, lollipop shape, arrowhead shape, or other
suitable structure to resist passing back between the leaflets.
Optionally, the retention elements 1890 may be configured to press
against, frictionally engage with, or penetrate the tissue of the
native annulus, posterior leaflet, or atrial wall. In still other
embodiments, the retention elements 1890 may be configured to
engage and optionally penetrate into the ventricular wall. For
example, a ventricular wall-engaging surface of the repair device
may have one or more retention members in the form of spikes,
barbs, ridges, bumps, hooks, or other frictional or
wall-penetrating structures disposed thereon. Such retention
members can be delivered through a central lumen of the repair
device 1800 after placement, or be automatically deployed as the
repair device 1800 expands.
[0112] FIG. 19 is a side cross-sectional view of the repair device
1800 after the repair device has been implanted under the posterior
leaflet PL of a native mitral valve MV. In this embodiment, the
retention elements 1890 extend from the support 1810 between the
leaflets to an upstream or super-annular side of the leaflets.
Preferably, the retention elements 1890 are mounted near the ends
1812, 1814 of the support 1810 so as to extend through the
commissures of the valve to the upstream side (shown in more detail
in FIG. 20C below). Alternatively, the retention elements 1890 can
penetrate through the leaflet itself (shown in more detail in FIG.
19).
[0113] FIG. 20A is a schematic top view of a native mitral valve MV
in the heart viewed from the left atrium and showing normal closure
of a native posterior leaflet (PL) and a native anterior leaflet
(AL), and FIG. 20B is a schematic top view of a native mitral valve
MV in the heart viewed from the left atrium and showing abnormal
closure of the posterior and anterior leaflets PL, AL. In FIG. 20B,
the posterior leaflet PL fails to sufficiently coapt with the
anterior leaflet AL, which in turn allows blood to regurgitate
through the valve. FIG. 20C is a schematic top view showing an
embodiment of the repair device 1800 (shown in dotted lines)
implanted at a subannular location of the otherwise abnormally
closed native mitral valve MV of FIG. 20B in accordance with an
embodiment of the present technology. As shown in FIG. 20C, after
the repair device 1800 is deployed behind the posterior leaflet PL
in the subannular position, the repair device 1800 braces the
posterior leaflet PL from the backside surface of the leaflet to
support the leaflet in at least a partially closed position in
which it sufficiently coapts with the anterior leaflet AL to reduce
or eliminate regurgitation. The posterior leaflet PL in this
example is braced such that it remains in a substantially closed
position and is substantially prevented from moving away from the
anterior leaflet AL during the cardiac cycle. The anterior leaflet
AL can continue to open and close during diastole and systole,
respectively. The repair device 1800 includes one or more retention
elements 1890 as described above with respect to FIGS. 18 and 19.
For example, the retention elements 1890 are shown extending
through the commissures of the valve to the upstream side.
[0114] Various aspects of the present technology provide heart
valve repair devices that can reduce the effective annular area of
the mitral valve orifice, by holding the posterior leaflet
permanently closed, or in other embodiments mostly closed, or in
further embodiments in an extended position beyond its natural
closed position state. When the repair device is deployed at the
target region of the mitral valve, the native valve may have only a
functional anterior leaflet, thereby reducing the effective orifice
area. Not to be bound by theory, the remaining effective orifice
area is believed to be sufficient to avoid a physiologically
detrimental or an excessive pressure gradient through the mitral
orifice during systole. Regurgitant mitral valves typically have
dilated to a size much larger than their original area, so a
reduction in the orifice area may not compromise the valve.
Additionally, many conventional mitral valve repair surgeries
result in a posterior leaflet that extends only a very short
distance from the posterior annulus. After these surgeries, the
motion of the anterior leaflet provides nearly all of the orifice
area. Accordingly, immobilization of the posterior leaflet of a
dilated mitral valve in the closed position is not believed to lead
to hemodynamic complications due to a high pressure gradient during
antegrade flow through the valve.
[0115] Following implantation and deployment of the repair device
in the target location, and while the device extends and holds the
posterior leaflet of the mitral valve at least partially in the
closed position, the device additionally can apply tension from the
valve leaflet to the chordae tendineae attached to the papillary
muscles and the ventricular wall. This additional tension applied
by the implanted repair device can, in some embodiments, pull the
papillary muscles and the free wall of the left ventricle closer to
the mitral valve to reduce the tethering effect on the anterior
leaflet and allow the anterior leaflet to close more effectively.
Thus, in addition to the hemodynamic benefit of a competent mitral
valve by at least partially closing the posterior leaflet, the
device might slightly improve morphology of both the anterior
leaflet and the left ventricle, and help the valve to provide a
structural benefit to the ventricle.
[0116] In another aspect of the present technology, several
embodiments of the repair device 100 can be used in conjunction
with a prosthetic heart valve replacement device delivered
percutaneously or trans-apically to treat an abnormal or diseased
native heart valve. Percutaneous or transapical replacement of the
mitral valve is particularly challenging due, at least in part, to
the non-circular, large, and asymmetric shape of the mitral
annulus. In addition, a diseased mitral valve can enlarge over time
making implantation of a percutaneous prosthetic heart valve even
more challenging. In accordance with an embodiment of the present
technology, the repair device 100 can be configured to change
either an annulus shape or an annulus cross-sectional dimension
when the device 100 is in the deployed configuration. In a
particular example, the repair device 100 can be implanted in the
sub annular position behind a posterior leaflet PL of a native
mitral valve MV to decrease the effective size of the mitral valve
annulus. In another embodiment, the repair device 100 can be
configured to change the native annulus shape to a more circular
shape or having a circular orifice, which may be advantageous for
receiving some variations of implantable prosthetic heart valves.
In one embodiment, the repair device 100 may be implanted in a
first surgical step and implantation of a prosthetic heart valve
device may occur at a second surgical step either immediately or at
some future date.
[0117] FIG. 21A is a schematic top view of a native mitral valve MV
in the heart viewed from the left atrium and showing a heart valve
repair device 100 (shown in dotted lines) implanted at the native
mitral valve wherein the opposing ends 112, 114 of the repair
device 100 extend beyond the native valve commissures of the
posterior leaflet PL. In this embodiment the first and second ends
112, 114 can support at least a portion of the anterior leaflet AL
and/or create a smaller and/or circular native mitral valve orifice
170 for receiving a replacement heart valve device. FIG. 21B
illustrates another embodiment of a heart valve repair device 100
(shown in dotted lines) implanted at the native mitral valve MV,
wherein the repair device 100 has first and second ends 112, 114
that extend beyond the native valve commissures and meet, overlap
and/or join behind the anterior leaflet AL. Additional
strengthening and/or stiffening materials (e.g., nitinol, stainless
steel, etc.) can be used, in some embodiments, to hold the ends
112, 114 in desired locations behind the anterior leaflet AL. In
the embodiment shown in FIG. 21B, the device 100 can either
partially or fully support the subannular region behind the
anterior leaflet AL as well as partially or fully support the
anterior leaflet AL to effectively shrink the effective annular
area and/or create a smaller and/or more circular native mitral
valve orifice 170 for receiving a replacement heart valve
device.
[0118] In one example, the smaller and/or circular native mitral
valve orifice 170 may be able to accommodate valve prostheses
designed for implantation in circular orifices, such as aortic
valve replacement devices. For example, FIG. 21C is a schematic top
view of the native mitral valve MV shown in FIG. 21A and showing
the heart valve repair device 100 (shown in dotted lines) and a
prosthetic heart valve 180 implanted at the native mitral valve
MV.
[0119] As described above with respect to FIGS. 7-10B, a variety of
percutaneous and minimally invasive techniques can be used to
access and implant the heart valve repair devices disclosed herein.
In one specific embodiment, and in accordance with an embodiment of
the present technology, FIG. 22 illustrates a method 2200 for
repairing a native valve of a patient. The method 2200 can include
positioning a heart valve repair device in a subannular position
and behind at least one leaflet, wherein the leaflet is connected
to chordae tendineae (block 2202). The repair device can have a
support in a contracted configuration. Optionally, the support can
include an extension unit configured to be biocompatible with
cardiac tissue at or near the native valve of the patient. The
method 2200 can also include extending the support in the
subannular position such that the support engages an interior
surface of a heart wall and a backside of the at least one leaflet
(block 2204). Further optional steps of the method 2200 can include
injecting a filler material into the extension unit (block
2206).
[0120] In one embodiment, positioning of a heart valve repair
device can include placing a percutaneously positioned guide
catheter with its distal tip approaching one of the mitral valve
commissures and positioned at the end of the groove behind the
posterior leaflet. A steerable guidewire and flexible catheter can
then be advanced from the guide catheter around the groove behind
the posterior leaflet and in the direction of the other opposite
commissure. Once the catheter is in place, the guidewire can be
withdrawn and the repair device can be introduced (e.g., in a
contracted configuration) through the flexible catheter. If
necessary, a flexible secondary guiding catheter or sheath can be
placed over the guidewire or catheter before introducing the repair
device. The repair device can be contained in the contracted
configuration by a thin extension unit or sheath during the
introduction process. Once the repair device is positioned behind
the posterior leaflet, the sheath is withdrawn and the device is
deployed or inflated. Further guidance can be used to ensure that
the projections, if present, expand between the tertiary chordae
tendineae. In some embodiments, radiopaque markers can be
incorporated in known locations on the catheter, the sheath, or the
repair device to ensure proper delivery to the target location.
[0121] The repair devices, systems and methods disclosed herein may
also be used to repair and/or treat regurgitant tricuspid valves.
The tricuspid valve, like the mitral valve, has leaflets tethered
by chordae tendineae. Such a repair device as disclosed herein
might be deployed behind one, two or all three of the tricuspid
valve leaflets.
[0122] In still further applications, embodiments of the repair
devices in accordance with the present technology can be used to
enhance the functionality of various prosthetic valves. For
example, the repair device can be configured to push or brace
prosthetic leaflets or prosthetic aptation devices implanted at a
native heart valve thereby facilitating coaptation of the
prosthetic leaflets. In particular examples, several embodiments of
repair devices in accordance with the present technology can be
used to at least partially coapt (a) the prosthetic aptation
devices shown and described in U.S. Pat. No. 7,404,824 B1, filed by
Webler et al. on Nov. 12, 2003, which is herein incorporated by
reference or (b) the prosthetic leaflets of devices shown and
described in U.S. Pat. No. 6,730,118, filed by Spenser et al. on
Oct. 11, 2002 and/or U.S. Patent Publication No. 2008/0243245,
filed by Thambar et al. on May 28, 2008, which is also incorporated
herein by reference. In another embodiment, several embodiments of
repair devices in accordance with the present technology can also
be used concomitantly with other valve therapies, such as the
MitraClip.RTM. device sold by Abbott Laboratories, which connects
the free edges of the two leaflets of the mitral valve.
[0123] Various aspects of the present disclosure provide heart
valve repair devices, systems and methods for bracing at least a
portion of the posterior leaflet of the native mitral valve in a
closed or partially closed position to reduce or eliminate
regurgitation occurrence in the mitral valve, while retaining
enough effective valve area to prevent any significant pressure
gradient across the mitral valve. Other aspects of the present
disclosure provide heart valve repair devices, systems and methods
for reducing the effective area of the mitral orifice and/or
rendering a mitral valve competent without substantially reshaping
the native annulus. Additionally, while additional tethering or
anchoring mechanisms known in the art can be used to anchor the
device in the target location, the devices described herein do not
require additional tethering or anchoring mechanisms.
[0124] The above detailed descriptions of embodiments of the
technology are not intended to be exhaustive or to limit the
technology to the precise form disclosed above. Although specific
embodiments of, and examples for, the technology are described
above for illustrative purposes, various equivalent modifications
are possible within the scope of the technology as those skilled in
the relevant art will recognize. For example, although steps are
presented in a given order, alternative embodiments may perform
steps in a different order. The various embodiments described
herein may also be combined to provide further embodiments. The
embodiments, features, systems, devices, materials, methods and
techniques described herein may, in certain embodiments, be applied
to or used in connection with any one or more of the embodiments,
features, systems, devices, materials, methods and techniques
disclosed in U.S. Provisional Patent Application No. 61/825,491,
which is incorporated herein by reference in its entirety.
[0125] From the foregoing, it will be appreciated that specific
embodiments of the technology have been described herein for
purposes of illustration, but well-known structures and functions
have not been shown or described in detail to avoid unnecessarily
obscuring the description of the embodiments of the technology.
Where the context permits, singular or plural terms may also
include the plural or singular term, respectively.
[0126] Moreover, unless the word "or" is expressly limited to mean
only a single item exclusive from the other items in reference to a
list of two or more items, then the use of "or" in such a list is
to be interpreted as including (a) any single item in the list, (b)
all of the items in the list, or (c) any combination of the items
in the list. Additionally, the term "comprising" is used throughout
to mean including at least the recited feature(s) such that any
greater number of the same feature and/or additional types of other
features are not precluded. It will also be appreciated that
specific embodiments have been described herein for purposes of
illustration, but that various modifications may be made without
deviating from the technology. Further, while advantages associated
with certain embodiments of the technology have been described in
the context of those embodiments, other embodiments may also
exhibit such advantages, and not all embodiments need necessarily
exhibit such advantages to fall within the scope of the technology.
Accordingly, the disclosure and associated technology can encompass
other embodiments not expressly shown or described herein.
[0127] The following clauses illustrate example subject matter
described herein.
[0128] Clause 1. A mitral valve repair device, comprising: a frame
comprising a shape memory material; and an extension unit
positioned around at least a portion of the frame, the extension
unit comprising a flexible material configured to move from a
contracted configuration for delivery to an expanded configuration,
the extension unit having an inner volume configured to be filled
with blood in the expanded configuration, and the extension unit
configured to extend inwardly toward a central axis of an orifice
of a native mitral valve to close a gap relative to a free edge of
an anterior leaflet of the native mitral valve in the expanded
configuration.
[0129] Clause 2. The mitral valve repair device of clause 1,
wherein the flexible material comprises a cover, and wherein the
cover is configured to enable tissue ingrowth.
[0130] Clause 3. The mitral valve repair device of clause 1 or 2,
wherein, when in the contracted configuration, the frame and the
extension unit are sized to fit within a delivery catheter.
[0131] Clause 4. The mitral valve repair device of any one of
clauses 1 through 3, wherein the extension unit comprises a fluid
absorbing material within the inner volume.
[0132] Clause 5. The mitral valve repair device clause 4, wherein
the fluid absorbing material comprises a foam.
[0133] Clause 6. The mitral valve repair device clause 4, wherein
the fluid absorbing material comprises a hydrogel.
[0134] Clause 7. The mitral valve repair device of any one of
clauses 4 through 6, wherein, when in contact with the blood, the
fluid absorbing material is configured to expand to inflate the
extension unit from the contracted configuration to the expanded
configuration.
[0135] Clause 8. The mitral valve repair device of any one of
clauses 1 through 7, wherein the extension unit is configured to
push at least a portion of a posterior leaflet of the native mitral
valve toward the anterior leaflet of the native mitral valve.
[0136] Clause 9. The mitral valve repair device of any one of
clauses 1 through 8, wherein the extension unit comprises an
inflatable bladder within the inner volume and extending the
extension unit comprises injecting the blood into the inflatable
bladder.
[0137] Clause 10. The mitral valve repair device of any one of
clauses 1 through 9, wherein the frame is configured to, in
response to deployment from a delivery catheter, move from a
collapsed configuration toward a deployed configuration, and
wherein, when in the deployed configuration, the frame is
configured to press against an underside of a posterior leaflet of
the native mitral valve.
[0138] Clause 11. The mitral valve repair device of any one of
clauses 1 through 10, wherein the extension unit comprises a
plurality of projections and a plurality of depressions, each
depression being disposed between two of the projections, wherein
at least some of the projections are configured to engage an
underside of a posterior leaflet of the native mitral valve, and
wherein at least some of the depressions are configured to receive
chordae tendineae coupled to the underside of the posterior
leaflet.
[0139] Clause 12. A method of repairing a native mitral valve
having an anterior leaflet and a posterior leaflet between a left
atrium and a left ventricle, comprising: implanting a mitral valve
repair device under the posterior leaflet, wherein the mitral valve
repair device comprises: a frame defined by a shape memory
material; and an extension unit positioned around at least a
portion of the frame, the extension unit comprising a flexible
material configured to move from a contracted configuration for
delivery to an expanded configuration; and inflating, with blood,
an inner volume of the extension unit to move the flexible material
from the contracted configuration to the expanded configuration and
to extend inwardly toward a central axis of the valve orifice to
close a gap relative to a free edge of an anterior leaflet of a
native mitral valve in the expanded configuration.
[0140] Clause 13. The method of clause 12, wherein positioning the
mitral valve repair device under the posterior leaflet comprises
positioning the extension unit in the contracted configuration
under the posterior leaflet, and wherein inflating the at least one
pocket comprises expanding the cover to presses against a wider
portion of the posterior leaflet in the expanded configuration
relative to the contracted configuration.
[0141] Clause 14. The method of clause 12 or 13, wherein the method
further comprises, before inflating the at least one pocket,
releasing the frame from a collapsed configuration such that the
frame moves toward a deployed configuration to press against an
underside of the posterior leaflet.
[0142] Clause 15. The method of any one of clauses 12 through 14,
wherein the extension unit comprises a plurality of projections and
a plurality of depressions, each depression being disposed between
two of the projections, and wherein inflating the at least one
pocket comprises extending the projections along an underside of
the posterior leaflet such that an upper side of the projections
presses against the posterior leaflet and the chordae tendineae are
positioned in at least some of the depressions.
[0143] Clause 16. The method of any one of clauses 12 through 15,
wherein inflating the at least one pocket further comprises closing
a gap relative to free edges of the posterior leaflet and the
anterior leaflet.
[0144] Clause 17. A medical system for repairing a native valve of
a patient, the system comprising: a delivery catheter extending
from a proximal portion controllable by a clinician to a distal
portion introducible into a vasculature of a patient; and a valve
repair device positioned within the distal portion of the delivery
catheter, wherein the valve repair device comprises: a frame
defined by a shape memory material; and an extension unit
positioned around at least a portion of the frame, the extension
unit comprising a flexible material configured to move from a
contracted configuration for delivery to an expanded configuration,
the extension unit having an inner volume configured to be filled
with blood in the expanded configuration, wherein the delivery
catheter is configured to deploy the valve repair device in the
contracted configuration into a subannular position behind at least
one leaflet of a native valve connected to chordae tendineae, and
wherein the extension unit, when in the expanded configuration, is
configured to extend inwardly toward a central axis of an orifice
of the native valve to close a gap relative to a free edge of the
at least one leaflet of the native valve in the expanded
configuration.
[0145] Clause 18. The medical system of clause 17, wherein the
native valve is a mitral valve, and wherein the heart wall is a
left ventricular wall and the leaflet is a posterior mitral valve
leaflet.
[0146] Clause 19. The medical system of clause 17 or 18, wherein
the chordae tendineae are basal or tertiary chordae tendineae.
[0147] Clause 20. The medical system of any one of clauses 17
through 19, wherein the valve repair device is configured to engage
the heart wall and the underside of the at least one leaflet
without penetrating the heart wall tissue or the leaflet.
* * * * *