U.S. patent application number 14/011590 was filed with the patent office on 2014-03-06 for heart valve sealing devices.
This patent application is currently assigned to Edwards Lifesciences Corporation. The applicant listed for this patent is Edwards Lifesciences Corporation. Invention is credited to Mark Chau, Sergio Delgado, Travis Oba, Robert C. Taft.
Application Number | 20140067048 14/011590 |
Document ID | / |
Family ID | 50188535 |
Filed Date | 2014-03-06 |
United States Patent
Application |
20140067048 |
Kind Code |
A1 |
Chau; Mark ; et al. |
March 6, 2014 |
Heart Valve Sealing Devices
Abstract
This disclosure pertains generally to prosthetic devices and
related methods for helping to seal native heart valves and prevent
or reduce regurgitation therethrough, as well as devices and
related methods for implanting such prosthetic devices. In some
cases, a spacer having a single anchor can be implanted within a
native heart valve. In some cases, a spacer having dual anchors can
be implanted within a native heart valve. In some cases, devices
can be used to extend the effective length of a native heart valve
leaflet.
Inventors: |
Chau; Mark; (Aliso Viejo,
CA) ; Oba; Travis; (Brea, CA) ; Delgado;
Sergio; (Irvine, CA) ; Taft; Robert C.;
(Irvine, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Edwards Lifesciences Corporation |
Irvine |
CA |
US |
|
|
Assignee: |
Edwards Lifesciences
Corporation
Irvine
CA
|
Family ID: |
50188535 |
Appl. No.: |
14/011590 |
Filed: |
August 27, 2013 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
61697706 |
Sep 6, 2012 |
|
|
|
61763848 |
Feb 12, 2013 |
|
|
|
Current U.S.
Class: |
623/2.1 ;
623/2.36 |
Current CPC
Class: |
A61F 2/2454 20130101;
A61F 2230/0069 20130101; A61F 2/2436 20130101; A61F 2/2463
20130101; A61F 2/2412 20130101; A61F 2/243 20130101; A61F 2/2445
20130101; A61F 2250/0003 20130101; A61F 2/2442 20130101; A61F
2/2433 20130101; A61F 2/2457 20130101; A61F 2/2466 20130101; A61F
2/246 20130101 |
Class at
Publication: |
623/2.1 ;
623/2.36 |
International
Class: |
A61F 2/24 20060101
A61F002/24 |
Claims
1. A prosthetic device for treating heart valve regurgitation
comprising: a radially compressible and radially expandable body
having a first end, a second end, and an outer surface extending
from the first end to the second end; and an anchor having a
connection portion and a leaflet capture portion, wherein: the
connection portion is coupled to the body such that the leaflet
capture portion is biased against the outer surface of the body
when the body is in a radially expanded state; the prosthetic
device is configured to capture a leaflet of a native heart valve
between the leaflet capture portion of the anchor and the outer
surface of the body; and the body is configured to prevent blood
from flowing through the body in a direction extending from the
first end to the second end and in a direction extending from the
second end to the first end.
2. The device of claim 1, wherein: the outer surface of the body
comprises a first side against which the anchor is biased and a
second side opposite the first side; and the connection portion of
the anchor is coupled to the body on the second side of the
body.
3. The device of claim 2, wherein: the anchor comprises an
elongated member that is coupled to the second side of the body at
a connection location; and the elongated member comprises a
ventricular portion that extends from the connection location
across the first end of the body.
4. The device of claim 3, wherein the ventricular portion comprises
first and second ventricular portions and the first ventricular
portion is substantially parallel to the second ventricular
portion.
5. The device of claim 1, wherein: the body is radially
compressible to a compressed state in which a leaflet-receiving gap
exists between the body and the leaflet capture portion of the
anchor; and the body is resiliently radially self-expandable to the
radially expanded state.
6. The device of claim 1, wherein the anchor comprises a first clip
portion and a second clip portion, and wherein the device is
configured to capture the leaflet between the first and second clip
portions.
7. The device of claim 1, wherein the body is formed from Nitinol
and is radially self-expandable to the expanded state.
8. The device of claim 1, wherein the body comprises a metallic
frame and a blood-impermeable fabric mounted on the frame.
9. The device of claim 1, wherein the body is configured to allow
blood to flow around the body between the body and a non-captured
leaflet during diastole, and configured to allow the non-captured
leaflet to close around the body to prevent mitral regurgitation
during systole.
10. The device of claim 1, wherein: the anchor is coupled to the
first end of the body; and the device further comprises an atrial
stabilizing member extending from the second end of the body.
11. The device of claim 1, wherein the body is configured to move
within the native heart valve along with motion of the captured
leaflet.
12. The device of claim 1, wherein an atrial end portion of the
body comprises a tapered shoulder that reduces in diameter moving
toward the atrial end portion of the body.
13. The device of claim 1, wherein the body comprises a crescent
cross-sectional shape.
14. The device of claim 1, wherein the anchor comprises first and
second anchors.
15. The device of claim 14, wherein the device is configured to be
secured to both native mitral valve leaflets.
16. A method of implanting a prosthetic sealing device at a native
mitral valve of a heart, the method comprising: advancing a
delivery catheter to a native mitral valve region of a heart from a
left atrium of the heart, the delivery catheter housing the
prosthetic sealing device in a radially compressed configuration;
advancing the prosthetic sealing device distally relative to the
delivery catheter such that an anchor of the prosthetic sealing
device moves out of the catheter and forms a leaflet-receiving gap
between an end portion of the anchor and the delivery catheter;
positioning either a posterior or an anterior mitral valve leaflet
in the gap; and advancing a radially compressed body of the
prosthetic sealing device out of the delivery catheter such that
the body self-expands radially toward the end portion of the
anchor, reducing the gap, and capturing the leaflet between the
body and the end portion of the anchor, wherein the body is
configured to prevent the flow of blood through the body during
systole and during diastole.
17. The method of claim 16, wherein a non-captured one of the
anterior and posterior leaflets is not secured to the prosthetic
sealing device when the prosthetic sealing device is implanted at
the native mitral valve.
18. The method of claim 16, wherein advancing a delivery catheter
through the native mitral valve from a left atrium comprises
advancing the delivery catheter through an incision in a portion of
a septum between the left atrium and a right atrium.
19. The method of claim 16, wherein when the delivery catheter is
advanced to the native mitral valve region of the heart, the anchor
is held in a substantially straightened position within the
delivery catheter extending distally from body of the prosthetic
sealing device.
20. A method of implanting a prosthetic sealing device at a native
mitral valve, the method comprising: advancing a delivery device to
a native mitral valve region via a left ventricle, the delivery
catheter housing the prosthetic sealing device in a compressed
configuration; allowing an anchor of the prosthetic sealing device
to move radially out of the delivery device while a body of the
prosthetic sealing device is in a compressed configuration, such
that a leaflet-receiving gap forms between an end portion of the
anchor and the delivery device; positioning either a posterior or
an anterior mitral valve leaflet in the gap; and allowing the body
of the prosthetic sealing device to radially self-expand such that
the leaflet is captured between the body and the anchor, wherein
the body is configured to prevent the flow of blood through the
body during systole and during diastole.
21. The method of claim 20, wherein a non-captured one of the
anterior and posterior mitral valve leaflets is not secured to the
prosthetic sealing device when the prosthetic sealing device is
implanted at the native mitral valve.
22. The method of claim 20, wherein advancing a delivery device to
a native mitral valve region via a left ventricle comprises
inserting the delivery device into the left ventricle through an
incision in an apex of the left ventricle.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Patent Application Nos. 61/697,706, filed Sep. 6, 2012, and
61/763,848, filed Feb. 12, 2013, which are each hereby incorporated
herein by reference in their entirety.
FIELD
[0002] This disclosure pertains generally to prosthetic devices and
related methods for helping to seal native heart valves and prevent
or reduce regurgitation therethrough, as well as devices and
related methods for implanting such prosthetic devices.
BACKGROUND
[0003] The native heart valves (i.e., the aortic, pulmonary,
tricuspid and mitral valves) serve critical functions in assuring
the forward flow of an adequate supply of blood through the
cardiovascular system. These heart valves can be rendered less
effective by congenital malformations, inflammatory processes,
infectious conditions or disease. Such damage to the valves can
result in serious cardiovascular compromise or death. For many
years the definitive treatment for such disorders was the surgical
repair or replacement of the valve during open heart surgery.
However, such surgeries are highly invasive and are prone to many
complications. Therefore, elderly and frail patients with defective
heart valves often went untreated. More recently, transvascular
techniques have been developed for introducing and implanting
prosthetic devices in a manner that is much less invasive than open
heart surgery. Such transvascular techniques have increased in
popularity due to their high success rates.
[0004] A healthy heart has a generally conical shape that tapers to
a lower apex. The heart is four-chambered and comprises the left
atrium, right atrium, left ventricle, and right ventricle. The left
and right sides of the heart are separated by a wall generally
referred to as the septum. The native mitral valve of the human
heart connects the left atrium to the left ventricle. The mitral
valve has a very different anatomy than other native heart valves.
The mitral valve includes an annulus portion, which is an annular
portion of the native valve tissue surrounding the mitral valve
orifice, and a pair of cusps, or leaflets extending downward from
the annulus into the left ventricle. The mitral valve annulus can
form a "D" shaped, oval, or otherwise out-of-round cross-sectional
shape having major and minor axes. The anterior leaflet can be
larger than the posterior leaflet, forming a generally "C" shaped
boundary between the abutting free edges of the leaflets when they
are closed together.
[0005] When operating properly, the anterior leaflet and the
posterior leaflet function together as a one-way valve to allow
blood to flow only from the left atrium to the left ventricle. The
left atrium receives oxygenated blood from the pulmonary veins.
When the muscles of the left atrium contract and the left ventricle
dilates, the oxygenated blood that is collected in the left atrium
flows into the left ventricle. When the muscles of the left atrium
relax and the muscles of the left ventricle contract, the increased
blood pressure in the left ventricle urges the two leaflets
together, thereby closing the one-way mitral valve so that blood
cannot flow back to the left atrium and is instead expelled out of
the left ventricle through the aortic valve. To prevent the two
leaflets from prolapsing under pressure and folding back through
the mitral annulus toward the left atrium, a plurality of fibrous
cords called chordae tendineae tether the leaflets to papillary
muscles in the left ventricle.
[0006] Mitral regurgitation occurs when the native mitral valve
fails to close properly and blood flows into the left atrium from
the left ventricle during the systole phase of heart contraction.
Mitral regurgitation is the most common form of valvular heart
disease. Mitral regurgitation has different causes, such as leaflet
prolapse, dysfunctional papillary muscles and/or stretching of the
mitral valve annulus resulting from dilation of the left ventricle.
Mitral regurgitation at a central portion of the leaflets can be
referred to as central jet mitral regurgitation and mitral
regurgitation nearer to one commissure (i.e., location where the
leaflets meet) of the leaflets can be referred to as eccentric jet
mitral regurgitation.
[0007] Some prior techniques for treating mitral regurgitation
include stitching portions of the native mitral valve leaflets
directly to one another. Other prior techniques include the use of
a spacer implanted between the native mitral valve leaflets.
Despite these prior techniques, there is a continuing need for
improved devices and methods for treating mitral valve
regurgitation.
SUMMARY
[0008] This disclosure pertains generally to prosthetic devices and
related methods for helping to seal native heart valves and prevent
or reduce regurgitation therethrough, as well as devices and
related methods for implanting such prosthetic devices.
[0009] In some embodiments, a prosthetic device for treating heart
valve regurgitation comprises a radially compressible and radially
expandable body having a first end, a second end, and an outer
surface extending from the first end to the second end and an
anchor having a connection portion and a leaflet capture portion,
wherein the connection portion is coupled to the body such that the
leaflet capture portion is biased against the outer surface of the
body when the body is in a radially expanded state, the prosthetic
device is configured to capture a leaflet of a native heart valve
between the leaflet capture portion of the anchor and the outer
surface of the body, and the body is configured to prevent blood
from flowing through the body in a direction extending from the
first end to the second end and in a direction extending from the
second end to the first end.
[0010] In some embodiments, the outer surface of the body comprises
a first side against which the anchor is biased and a second side
opposite the first side, and the connection portion of the anchor
is coupled to the body on the second side of the body. In some
embodiments, the anchor comprises an elongated member that is
coupled to the second side of the body at a connection location and
the elongated member comprises a ventricular portion that extends
from the connection location across the first end of the body. In
some embodiments, the ventricular portion comprises first and
second ventricular portions and the first ventricular portion is
substantially parallel to the second ventricular portion.
[0011] In some embodiments, the body is radially compressible to a
compressed state in which a leaflet-receiving gap exists between
the body and the leaflet capture portion of the anchor, and the
body is resiliently radially self-expandable to the radially
expanded state. In some embodiments, the anchor comprises a first
clip portion and a second clip portion, and the device is
configured to capture the leaflet between the first and second clip
portions. In some embodiments, the body is formed from Nitinol and
is radially self-expandable to the expanded state. In some
embodiments, the body comprises a metallic frame and a
blood-impermeable fabric mounted on the frame. In some embodiments,
the body is configured to allow blood to flow around the body
between the body and a non-captured leaflet during diastole, and
configured to allow the non-captured leaflet to close around the
body to prevent mitral regurgitation during systole.
[0012] In some embodiments, the anchor is coupled to the first end
of the body and the device further comprises an atrial stabilizing
member extending from the second end of the body. In some
embodiments, the body is configured to move within the native heart
valve along with motion of the captured leaflet. In some
embodiments, an atrial end portion of the body comprises a tapered
shoulder that reduces in diameter moving toward the atrial end
portion of the body. In some embodiments, the body comprises a
crescent cross-sectional shape. In some embodiments, the anchor
comprises first and second anchors and the device is configured to
be secured to both native mitral valve leaflets.
[0013] In some embodiments, a prosthetic device for treating heart
valve regurgitation comprises a main body portion having a
connection portion and a free end portion, wherein the connection
portion is configured to be coupled to a first one of the two
native mitral valve leaflets such that the device is implanted
within a native mitral valve orifice, and when the device is
implanted within the native mitral valve orifice, the free end
portion moves laterally toward a second one of the two native
mitral valve leaflets during systole, thereby helping to seal the
orifice and reduce mitral regurgitation during systole, and the
free end portion moves laterally away from the second native mitral
valve leaflet during diastole to allow blood to flow from the left
atrium to the left ventricle during diastole.
[0014] In some embodiments, the connection portion of the main body
is thicker than the free end portion. In some embodiments, the main
body portion further comprises an atrial portion that contacts the
native mitral valve annulus within the left atrium adjacent to the
first native mitral valve leaflet. In some embodiments, the device
further comprises a ventricular anchor that clips around a lower
end of the first native mitral valve leaflet, thereby securing the
device to the first native mitral valve leaflet. In some
embodiments, the anchor comprises a paddle shape with a broad upper
end portion and a relatively narrow neck portion, wherein the neck
portion couples the upper end portion to the main body.
[0015] In some embodiments, a prosthetic device comprises a sheet
of flexible, blood-impermeable material configured to be implanted
within a native mitral valve orifice and coupled to a first one of
the two native mitral leaflets or to the native mitral annulus
adjacent the first native mitral leaflet, wherein when implanted
the sheet is configured to inflate with blood during systole such
that a free portion of the sheet not coupled to the first native
mitral leaflet or the mitral annulus adjacent the first native
mitral leaflet moves laterally toward and seals against the second
of the two native mitral leaflets to reduce mitral regurgitation,
and when implanted the sheet is configured to deflate during
diastole such that the portion of the sheet not coupled to the
first native mitral leaflet or the native mitral annulus adjacent
the first native mitral leaflet moves laterally away from the
second native mitral leaflet to allow blood to flow from the left
atrium to the left ventricle.
[0016] In some embodiments, the sheet is supported by a rigid frame
that is secured to the first native mitral leaflet. In some
embodiments, the frame comprises a ventricular anchor that clips
around a lower end of the first native mitral leaflet. In some
embodiments, the frame comprises an atrial portion that contacts
the native mitral annulus within the left atrium adjacent to the
first native mitral leaflet. In some embodiments, an upper end of
the sheet is secured directly to the native mitral annulus adjacent
the first native mitral leaflet or to the first native mitral
leaflet adjacent the native mitral annulus. In some embodiments,
the upper end of the sheet is secured to native tissue via rigid
anchors that puncture the native tissue.
[0017] In some embodiments, the sheet comprises an annular
cross-sectional profile perpendicular to an axis extending through
the mitral orifice from the left atrium to the left ventricle. In
some embodiments, the sheet comprises a closed atrial end and an
open ventricular end. In some embodiments, the open lower end is
biased toward an open position and is configured to collapse to a
closed position during diastole. In some embodiments, the sheet is
supported by a rigid frame that is secured to the first native
mitral leaflet, and the frame comprises a plurality of longitudinal
splines extending from the upper end of the sheet to the lower end
of the sheet. In some embodiments, the splines are biased to cause
the lower end of the sheet to open away from the first native
leaflet.
[0018] In some embodiments, a lower end of the sheet is tethered to
a location in the left ventricle below the native mitral leaflets.
In some embodiments, the lower end of the sheet is tethered to the
papillary muscle heads in the left ventricle. In some embodiments,
the lower end of the sheet is tethered to a lower end of the rigid
frame. In some embodiments, opposing lateral ends of the lower end
of the sheet are tethered to the lower end of the frame such that
an intermediate portion of the lower end of the sheet can billow
out away from the frame and toward the second leaflet during
systole. In some embodiments, the sheet has a generally trapezoidal
shape, with a broader portion adjacent to the mitral annulus and a
narrower portion positioned between the native mitral leaflets.
[0019] In some embodiments, a prosthetic device for treating heart
valve regurgitation comprises a radially compressible and radially
expandable body having a first end, a second end, and an outer
surface extending from the first end to the second end, a first
anchor coupled to the body and configured to capture the anterior
native mitral valve leaflet between the first anchor and the body
to secure the device to the anterior leaflet, and a second anchor
coupled to the body and configured to capture the posterior native
mitral valve leaflet between the second anchor and the body to
secure the device to the posterior leaflet, wherein when the first
and second anchors capture the anterior and posterior leaflets, the
body is situated within a mitral valve orifice between the anterior
and posterior leaflets, thereby decreasing a size of the
orifice.
[0020] In some embodiments, the body is radially compressible to a
collapsed delivery configuration suitable for delivering the device
to the native mitral valve, and radially expandable from the
collapsed delivery configuration to an expanded, operational
configuration suitable for operation in the native mitral valve. In
some embodiments, the body is formed from Nitinol and is radially
self-expandable from the collapsed configuration to the expanded
configuration. In some embodiments, the device further comprises a
sheet of blood impermeable fabric covering the body. In some
embodiments, the body has an elliptical cross-sectional shape. In
some embodiments, the body has a crescent cross-sectional shape. In
some embodiments, the body comprises a prosthetic valve. In some
embodiments, the body is configured to prevent blood from flowing
through the body in a direction extending from the first end to the
second end and in a direction from the second end to the first
end.
[0021] In some embodiments, a method of implanting a prosthetic
sealing device at a native mitral valve of a heart comprises
advancing a delivery catheter to a native mitral valve region of a
heart from a left atrium of the heart, the delivery catheter
housing the prosthetic sealing device in a radially compressed
configuration, advancing the prosthetic sealing device distally
relative to the delivery catheter such that an anchor of the
prosthetic sealing device moves out of the catheter and forms a
leaflet-receiving gap between an end portion of the anchor and the
delivery catheter, positioning either a posterior or an anterior
mitral valve leaflet in the gap, and advancing a radially
compressed body of the prosthetic sealing device out of the
delivery catheter such that the body self-expands radially toward
the end portion of the anchor, reducing the gap, and capturing the
leaflet between the body and the end portion of the anchor, wherein
the body is configured to prevent the flow of blood through the
body during systole and during diastole.
[0022] In some embodiments, a non-captured one of the anterior and
posterior leaflets is not secured to the prosthetic sealing device
when the prosthetic sealing device is implanted at the native
mitral valve. In some embodiments, advancing a delivery catheter
through the native mitral valve from a left atrium comprises
advancing the delivery catheter through an incision in a portion of
a septum between the left atrium and a right atrium. In some
embodiments, when the delivery catheter is advanced to the native
mitral valve region of the heart, the anchor is held in a
substantially straightened position within the delivery catheter
extending distally from body of the prosthetic sealing device.
[0023] In some embodiments, a method of implanting a prosthetic
sealing device at a native mitral valve comprises advancing a
delivery device to a native mitral valve region via a left
ventricle, the delivery catheter housing the prosthetic sealing
device in a compressed configuration, allowing an anchor of the
prosthetic sealing device to move radially out of the delivery
device while a body of the delivery device is in a compressed
configuration, such that a leaflet-receiving gap forms between an
end portion of the anchor and the delivery device, positioning
either a posterior or an anterior mitral valve leaflet in the gap,
and allowing the body of the prosthetic sealing device to radially
self-expand such that the leaflet is captured between the body and
the anchor, wherein the body is configured to prevent the flow of
blood through the body during systole and during diastole.
[0024] In some embodiments, a non-captured one of the anterior and
posterior mitral valve leaflets is not secured to the prosthetic
sealing device when the prosthetic sealing device is implanted at
the native mitral valve. In some embodiments, advancing a delivery
device to a native mitral valve region via a left ventricle
comprises inserting the delivery device into the left ventricle
through an incision in an apex of the left ventricle.
[0025] In some embodiments, a method of implanting a prosthetic
sealing device at a native mitral valve of a heart comprises
advancing a delivery system to a native mitral valve region of a
heart from a left ventricle of the heart, the delivery system
housing the prosthetic sealing device in a radially compressed
configuration, proximally retracting an outer sheath of the
delivery system such that anchors of the prosthetic sealing device
are not confined within the delivery system, advancing the delivery
system toward the left atrium of the heart such that native mitral
valve leaflets are positioned between the anchors of the prosthetic
sealing device and the delivery system, proximally retracting an
inner sheath of the delivery system such that a body of the
prosthetic sealing device is not confined within the delivery
system, wherein the body is configured to prevent the flow of blood
through the body during systole and during diastole, and removing
the delivery system from the native mitral valve region of the
heart.
[0026] In some embodiments, advancing the delivery system to the
native mitral valve region from the left ventricle comprises
inserting the delivery device into the left ventricle through an
incision in an apex of the left ventricle. In some embodiments,
when the delivery system is advanced to the native mitral valve
region of the heart, the anchor is held in a substantially
straightened position within the delivery catheter extending
distally along a side of the body of the prosthetic sealing
device.
[0027] In some embodiments, a method of implanting a prosthetic
sealing device at a native mitral valve of a heart comprises
advancing a delivery system to a native mitral valve region of a
heart from a left atrium of the heart, the delivery system housing
the prosthetic sealing device in a radially compressed
configuration, proximally retracting an outer sheath of the
delivery system such that anchors of the prosthetic sealing device
are not confined within the delivery system, retracting the
delivery system toward the left atrium of the heart such that
native mitral valve leaflets are positioned between the anchors of
the prosthetic sealing device and the delivery system, proximally
retracting an inner sheath of the delivery system such that a body
of the prosthetic sealing device is not confined within the
delivery system, wherein the body is configured to prevent the flow
of blood through the body during systole and during diastole, and
removing the delivery system from the native mitral valve region of
the heart.
[0028] In some embodiments, advancing the delivery system to the
native mitral valve region from the left atrium comprises advancing
the delivery system through an incision in a portion of a septum
between the left atrium and a right atrium. In some embodiments,
when the delivery system is advanced to the native mitral valve
region of the heart, the anchor is held in a substantially
straightened position within the delivery catheter extending
proximally from body of the prosthetic sealing device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] FIG. 1 shows a portion of a human heart with an exemplary
embodiment of a sealing device attached to the native posterior
mitral leaflet.
[0030] FIG. 2 shows a portion of a human heart with an exemplary
embodiment of a sealing device attached to the native anterior
mitral leaflet.
[0031] FIG. 3 shows a portion of a human heart with an exemplary
embodiment of a sealing device attached to the native posterior
mitral leaflet and having an atrial anchor.
[0032] FIG. 4 is an atrial end view of one embodiment of the
sealing device of FIG. 3 having a lattice-type atrial anchor.
[0033] FIG. 5 is an atrial end view of another embodiment of the
sealing device of FIG. 3 having a loop-type atrial anchor.
[0034] FIG. 6 is a side view of an exemplary sealing device.
[0035] FIG. 7 is another side view of the sealing device of FIG.
6.
[0036] FIG. 8 is an atrial end view of the sealing device of FIG.
6.
[0037] FIG. 9 is an atrial end view of the sealing device of FIG. 6
implanted at a native mitral valve.
[0038] FIG. 10 shows a crescent-shaped embodiment of a sealing
device.
[0039] FIG. 11 shows a sealing device having an anchor that extends
from one side of a body, around a ventricular end of the body, and
along a second side of the body.
[0040] FIGS. 12-15 show a method of deploying the sealing device of
FIG. 11 from a delivery sheath.
[0041] FIG. 16 is a side view of another embodiment of a sealing
device having an anchor that extends from one side of a body,
around a ventricular end of the body, and along a second side of
the body.
[0042] FIG. 17 is another side view of the embodiment of FIG.
16.
[0043] FIG. 18 is an atrial end view of the embodiment of FIG.
16.
[0044] FIG. 19 is a side view of an embodiment similar to that
shown in FIG. 16.
[0045] FIG. 20 shows the embodiment of FIG. 19 covered with a
fabric layer.
[0046] FIG. 21 is a ventricular end view of the embodiment of FIG.
20 implanted at a native mitral valve.
[0047] FIG. 22 shows a portion of a human heart with an exemplary
sealing device being implanted at the mitral region in a transeptal
approach.
[0048] FIG. 23 shows a portion of a human heart with an exemplary
sealing device being implanted at the mitral region in a
transapical approach.
[0049] FIG. 24 shows a human heart with an exemplary prosthetic
device attached to a native mitral leaflet.
[0050] FIG. 25 shows an exemplary prosthetic device being coupled
to a native mitral leaflet in a transeptal approach.
[0051] FIG. 26 shows an exemplary prosthetic device being coupled
to a native mitral leaflet in a transapical approach.
[0052] FIGS. 27 and 28 show another exemplary prosthetic device
being coupled to a native mitral leaflet.
[0053] FIGS. 29-31 show an exemplary prosthetic device attached to
the mitral valve region of a human heart.
[0054] FIGS. 32-34 show another exemplary prosthetic device
attached to the mitral valve region of a human heart.
[0055] FIG. 35 shows two exemplary prosthetic devices, each being
coupled to a respective one of the native mitral valve
leaflets.
[0056] FIG. 36 shows two exemplary prosthetic devices, each being
coupled to a respective one of the native mitral valve
leaflets.
[0057] FIG. 37 shows two exemplary prosthetic devices, each being
coupled to a respective one of the native mitral valve
leaflets.
[0058] FIGS. 38-41 show an exemplary prosthetic device having two
anchors.
[0059] FIG. 42 shows an exemplary prosthetic device having two
anchors, coupled to both of the native mitral valve leaflets.
[0060] FIG. 43 shows an exemplary prosthetic device having two
anchors, coupled to both of the native mitral valve leaflets, from
an atrial view.
[0061] FIG. 44 shows an exemplary prosthetic device having an
elongated body and two anchors, coupled to both of the native
mitral valve leaflets, from an atrial view.
[0062] FIG. 45 shows an exemplary prosthetic device having a valve
and two anchors, coupled to both of the native mitral valve
leaflets, from an atrial view.
[0063] FIG. 46 shows an exemplary prosthetic device having a
crescent-shaped body and two anchors, coupled to both of the native
mitral valve leaflets, from an atrial view.
[0064] FIGS. 47-51 show exemplary prosthetic devices having three
anchors.
[0065] FIGS. 52-54 show the prosthetic device of FIGS. 38-41
implanted at a native mitral valve.
[0066] FIGS. 55 and 56 show another exemplary prosthetic device
comprising a radially compressible and expandable body.
[0067] FIGS. 57 and 58 show the prosthetic device of FIGS. 55 and
56 with a fabric layer.
[0068] FIGS. 59-63 show an exemplary prosthetic device with an
exemplary delivery system, in various configurations.
[0069] FIGS. 64-67 show various exemplary delivery approaches for
delivering a prosthetic device to a native mitral valve.
[0070] FIG. 68 shows an exemplary prosthetic device including a
nosecone.
DETAILED DESCRIPTION
[0071] Described herein are embodiments of prosthetic devices that
are primarily intended to be implanted at one of the mitral,
aortic, tricuspid, or pulmonary valve regions of a human heart, as
well as apparatuses and methods for implanting the same. The
prosthetic devices can be used to help restore and/or replace the
functionality of a defective native mitral valve. The disclosed
embodiments should not be construed as limiting in any way.
Instead, the present disclosure is directed toward all novel and
nonobvious features and aspects of the various disclosed
embodiments, alone and in various combinations and sub-combinations
with one another.
Prosthetic Spacers
[0072] In some embodiments, a prosthetic device comprises a body
and an anchor. The body is configured to be positioned within the
native mitral valve orifice to help create a more effective seal
between the native leaflets to prevent or minimize mitral
regurgitation. The body can comprise a structure that is impervious
to blood and that allows the native leaflets to close around the
sides of the body during ventricular systole to block blood from
flowing from the left ventricle back into the left atrium. The body
is sometimes referred to herein as a spacer because the body can
fill a space between improperly functioning native mitral leaflets
that do not naturally close completely. In some embodiments, the
body can comprise a prosthetic valve structure positioned within an
annular body.
[0073] The body can have various shapes. In some embodiments, the
body can have an elongated cylindrical shape having a round
cross-sectional shape. In other embodiments, the body can have an
ovular cross-sectional shape, a crescent cross-sectional shape, or
various other non-cylindrical shapes. The body can have an atrial
or upper end positioned in or adjacent to the left atrium, a
ventricular or lower end positioned in or adjacent to the left
ventricle, and an annular side surface that extends between the
native mitral leaflets.
[0074] The anchor can be configured to secure the device to one or
both of the native mitral leaflets such that the body is positioned
between the two native leaflets. The anchor can attach to the body
at a location adjacent the ventricular end of the body. The anchor
can be configured to be positioned behind a native leaflet when
implanted such that the leaflet is captured between the anchor and
the body.
[0075] The prosthetic device can be configured to be implanted via
a delivery sheath. The body and the anchor can be compressible to a
radially compressed state and can be self-expandable to a radially
expanded state when compressive pressure is released. The device
can be configured to allow the anchor to self-expand radially away
from the still-compressed body initially in order to create a gap
between the body and the anchor. The leaflet can then be positioned
in the gap. The body can then be allowed to self-expand radially,
closing the gap between the body and the anchor and capturing the
leaflet between the body and the anchor. The implantation methods
for various embodiments can be different, and are more fully
discussed below with respect to each embodiment. Additional
information regarding these and other delivery methods can be found
in U.S. Patent Application Publication No. 2011/0137397 and U.S.
Provisional Patent Application No. 61/760,577, which are
incorporated by reference herein in their entirety.
[0076] Some embodiments disclosed herein are generally configured
to be secured to only one of the native mitral leaflets. However,
other embodiments comprise more than one anchor and can be
configured to be secured to both mitral leaflets. Unless otherwise
stated, any of the embodiments disclosed herein that comprise a
single anchor can optionally be secured to the anterior mitral
leaflet or secured to the posterior mitral leaflet, regardless of
whether the particular embodiments are shown as being secured to a
particular one of the leaflets.
[0077] Furthermore, some embodiments can optionally also include
one or more atrial anchors, such as to provide additional
stabilization. Unless otherwise stated, any of the embodiments
disclosed herein can optionally include an atrial anchor or not
include an atrial anchor, regardless of whether the particular
embodiments are shown with an atrial anchor or not.
[0078] Some of the disclosed prosthetic devices are prevented from
atrial embolization by having the anchor hooked around a leaflet,
utilizing the tension from native chordae tendinae to resist high
systolic pressure urging the device toward the left atrium. During
diastole, the devices can rely on the compressive forces exerted on
the leaflet that is captured between the body and the anchor to
resist embolization into the left ventricle.
[0079] FIG. 1 shows an exemplary embodiment of a prosthetic device
10 that comprises a body 12 and an anchor 14. The device 10 is
secured to the posterior mitral leaflet 8 with the free end of the
leaflet 8 captured between the anchor 14 and the body 12. In FIG.
1, the anterior mitral leaflet 6 is shown separated from the body
12 during diastole as blood flows from the left atrium 2 into the
left ventricle 4. As the mitral leaflets open apart from each
other, the device 10 can move with the posterior leaflet 8,
allowing the anterior leaflet 6 to open away from the body 12.
During systole, the back pressure on the leaflets closes them
together around the body 12 to prevent mitral regurgitation. FIG. 2
shows the device 10 alternatively secured to the anterior mitral
leaflet 6 with the posterior mitral leaflet 8 free to articulate
toward and away from the device 10.
[0080] FIG. 3 shows a prosthetic device 20 having a body 22, a
ventricular anchor 24, and an atrial anchor 26. The device 20 is
shown secured to the posterior leaflet 8 via the ventricular anchor
24. The atrial anchor 26 can extend laterally from adjacent the
atrial end of the body 22 toward the mitral annulus or other
lateral portions of the left atrium 2 adjacent to the posterior
leaflet 8. The atrial anchor 26 can help stabilize the device. For
example, the atrial anchor 26 can prevent the body 22 from tilting
and keep it oriented longitudinally along the blood flow direction
through the mitral orifice. The atrial anchor 26 can also help
prevent the device 20 from embolizing into the left ventricle
4.
[0081] FIGS. 4 and 5 are atrial end views showing two alternative
embodiments of atrial anchors for the device 20. FIG. 4 shows an
atrial anchor 26A that comprises a lattice-type framework supported
by two connections to the body 22, while FIG. 5 shows an atrial
anchor 26B that comprises a single elongated member extending in a
loop between two connections to the body 22. In both embodiments,
the atrial anchor comprises a relatively broader or wider end
portion configured to engage with the atrial tissue so as to spread
out the engagement forces to avoid tissue damage and promote
increased tissue ingrowth.
[0082] FIGS. 6-8 show three views of an exemplary embodiment of the
prosthetic device 20 having a cylindrical body 22, a ventricular
anchor 24, and an atrial anchor 26C. The ventricular anchor 24, as
shown in FIGS. 6 and 7, comprises an elongated member that extends
from two connection points adjacent the ventricular end of the body
22 and along one side of the body toward the atrial end of the
body. The ventricular anchor is contoured around the generally
cylindrical side surface of the body 22. The atrial anchor 26C
comprises a lattice-type framework made up of several
diamond-shaped segments 29 coupled side-by-side in an arc. The
atrial anchor 26C further comprises three connecting members 27
coupling it to the body 22 adjacent the atrial end of the body. As
shown in FIG. 6, the atrial member 26C extends generally laterally
to the same side of the body 22 as the ventricular anchor 24. The
radially outward end portion of the atrial anchor can have an
upward curvature to conform to the curved geometry of the left
atrium. Each of the diamond-shaped segments 29 comprises radially
outwardly pointing tip 30 that can press into and/or penetrate
adjacent tissue in some cases.
[0083] The device 20 is shown in an expanded configuration in FIGS.
3-9. In a compressed delivery configuration, the atrial anchor 26
can be folded down against the side of the body 22 or extended
upwardly away from the body 22. Furthermore, the atrial anchor 26
can be circumferentially compressed, especially embodiments having
a lattice-type structure.
[0084] The body 22 can comprise an annular metal frame 32 covered
with a blood-impervious fabric 28, as shown in FIGS. 6-9. One or
both ends of the body can also be covered with the blood-impervious
fabric 28, as shown in FIG. 8. The frame 32 can comprise a
mesh-like structure comprising a plurality of interconnected metal
struts, like a conventional radially compressible and expandable
stent. In other embodiments, the body can comprise a solid block of
material, such as flexible sponge-like block. In some embodiments,
the body 22 can be hollow or filled with material.
[0085] The frame 32 can be formed from a self-expandable material,
such as Nitinol. When formed from a self-expandable material, the
frame 32 can be radially compressed to a delivery configuration and
can be retained in the delivery configuration by placing the device
in the sheath of a delivery apparatus. When deployed from the
sheath, the frame 32 can self-expand to its functional size. In
other embodiments, the frame can be formed from a plastically
expandable material, such as stainless steel or a cobalt chromium
alloy. When formed from a plastically expandable material, the
prosthetic device can be crimped onto a delivery apparatus and
radially expanded to its functional size by an inflatable balloon
or an equivalent expansion mechanism It should be noted that any of
the embodiments disclosed herein can comprise a self-expandable
main body or a plastically expandable main body.
[0086] FIG. 9 is a view from the left atrium 2 of the device 20 of
FIGS. 6-8 implanted at a mitral valve. The body 22 is positioned
between the native leaflets 6, 8 in a sealed position with the
atrial anchor 26C engaged with the atrial tissue adjacent the
posterior mitral leaflet 8. The atrial end of the body 22 is open
while the ventricular end of the body is covered with the
impervious fabric 28.
[0087] FIG. 10 shows an exemplary prosthetic device 34 having a
crescent shaped body 36. The body 36 is configured to be positioned
with the convex side facing the posterior mitral leaflet 8 and the
concave side facing the anterior mitral leaflet 6. In this
embodiment, the body 36 can comprise a flexible, sponge-like
material. Consequently, the device 34 can comprise two ventricular
anchors to capture the anterior leaflet 6. A first ventricular
anchor 44 is configured to be positioned behind the anterior
leaflet while a second ventricular anchor 42 is configured to be
positioned between the body 36 and the anterior leaflet. The
anterior leaflet 6 is therefore captured and pinched between the
two anchors 42, 44 to secure the body 36 within the mitral orifice.
The device 34 relies on the two anchors 42, 44 to capture the
leaflet because the body 36 in this embodiment may lack sufficient
rigidity to grip the leaflet. Both of the ventricular anchors 42,
44 can extend from adjacent a ventricular end 40 of the body 36 and
extend up toward an atrial end 38 of the body along the same side
of the body. In other embodiments, the anchors 42, 44 can be
positioned on the convex side of the body 36 in order to secure the
body to the posterior leaflet. In some embodiments, the anchor 42
can be nested within the anchor 44 to provide a smaller crimped
profile. In other embodiments, the anchors 42, 44 can have various
other shapes. In still other embodiments, the body 36 can be
cylindrical or can have any of various other shapes described
herein.
[0088] FIG. 11 shows an exemplary embodiment of a prosthetic device
50 having a body 52 and an anchor 54 that attaches to a first side
of the body, extends around the ventricular end of the body, and
extends along a second side of the body opposite the first side of
the body. The device 50 is configured to capture a mitral leaflet
between the anchor 54 and the second side of the body 52 to secure
the body within the mitral orifice. The body 52 can comprise, for
example, a radially compressible and expandable metal stent covered
by a blood impermeable fabric, as described above.
[0089] FIGS. 12-15 illustrate an exemplary method of deployment of
the device 50 from a delivery catheter 56. In FIG. 12, the body 52
is shown in a radially compressed state within the catheter 56 with
the anchor 54 extending distally from the ventricular end of the
body in a straightened, or unfurled, state. The device 50 can be
resiliently deformed in this configuration such that the device 50
resiliently returns to the configuration shown in FIG. 11 when
released from constraint. A pusher member 59 can be used to push
the device 50 distally relative to the catheter 56 or to hold the
device 50 steady as the catheter is retracted. In FIG. 13, the
catheter 56 is retracted proximally from the device 50 and/or the
device 50 is advanced distally from the catheter 56 such that the
elongated anchor 54 begins to extend out of the distal outlet 58 of
the catheter. As the anchor 54 moves out of the outlet 58, the
anchor begins to naturally return toward the shape of FIG. 11,
curling gradually as it is freed from the confining forces of the
catheter. In FIG. 14, the entire anchor 54 has moved out of the
catheter 56 and has returned to its natural shape of FIG. 11.
However, the body 52 is still held in radial compression by the
catheter, creating a gap 60 between the second side of the body 52
and the end of the anchor 54. A mitral leaflet can be positioned
within the gap 60 while the device is in the configuration of FIG.
14. In FIG. 15, the ventricular end 62 of the body 52 begins to
advance out of the outlet 58, allowing the ventricular end 62 of
the body to radially expand while the atrial end 64 of the body
remains held in compression within the catheter. This causes the
body 52 to expand gradually toward the anchor 54, decreasing the
width of the gap 60, thereby capturing the leaflet within the gap.
Once the atrial end 64 of the body 52 is freed from the catheter
56, the entire body 52 can expand to its fully expanded state shown
in FIG. 11, pinching or compressing the leaflet between the end of
the anchor 54 and the side of the body. In the fully expanded state
shown in FIG. 11, a gap remains between the body 52 and the anchor
54, although the gap is desirably sized such that a leaflet is
engaged by the body and the anchor when placed in the gap. In
alternative embodiments, however, such a gap may not exist when the
device is in its fully expanded state (i.e., the anchor 54 contacts
the body 52 when a leaflet is not positioned between these two
components).
[0090] FIGS. 16-18 show orthogonal views of an exemplary embodiment
of a device 70 similar to the device 50. The device 70 can be
deployed from a catheter in the manner described above with respect
to FIGS. 11-15. The device 70 comprises a radially self-expandable
body 72 and a ventricular anchor 74. The body 72 can comprise a
narrowed atrial end 76 and a tapered shoulder region 77, such as to
provide improved hemodynamics as blood flows around the shoulder
region. The body 72 has a ventricular end 78 opposite from the
atrial end 76. The ventricular anchor 74 can comprise an elongated,
curved member that connects to the body 72 at two connection points
80, 82 adjacent to the ventricular end 78 on a first side of the
body (i.e., the right side of the body in FIG. 16). As shown in
FIGS. 16-18, the anchor 74 comprises first portions 84, 86 that
extend from the connection points 80, 82, respectively, around the
ventricular end 78 of the body, to a second, opposite side of the
body (i.e., the left side of the body in FIG. 16). The anchor 74
further comprises second portions 88, 90 that extend from the first
portions 84, 86, respectively, along the second side of the body
toward the atrial end 76 of the body. The second portions 88, 90
gradually expand apart from each other moving atrially toward an
end portion 92 of the anchor 74. The second portions 88, 90 and the
end portion 92 of the anchor 74 can form a paddle shape, as shown
in FIG. 17, and can have a circumferential curvature that
substantially matches the curvature of the body 72.
[0091] Note that, while FIGS. 16-18 appear to show the end portion
92 of the anchor passing within a portion of the body 72, the end
portion 92 actually extends around the outer surface of the body
72, as shown in FIGS. 19 and 20. The position of the end portion 92
in FIGS. 16-18 illustrates the position that the anchor 74 wants to
resiliently move toward in the absence of resistance from body 72.
When manufactured, the anchor 74 is provided with a pre-bend that
causes the end portion 92 to press against the outer surface of the
body 72, as shown in FIGS. 19 and 20. This provides the device 70
the ability to apply a strong enough clamping force on a leaflet
positioned between the end portion 92 and the body 72, even when
the leaflet is very thin.
[0092] FIG. 20 also shows a blood-impervious fabric layer 94
covering the body 72 which can prevent blood from flowing through
the body 72. The fabric layer can comprise, for example,
polyethylene terephthalate (PET) or polyurethane. Any of the
spacers described herein (even if shown just as a frame) can
include such a blood-impervious fabric layer covering the spacer,
which can prevent blood from flowing through the spacer.
[0093] The device 70 can be can be deployed from a delivery
catheter according to the method illustrated with respect to device
50 in FIGS. 11-15, by releasing the anchor 74 first to create a
leaflet-receiving gap between the end portion 92 and the body 72.
After positioning a leaflet in the gap, the body 72 can
subsequently be freed to self-expand radially toward the end
portion 92 to clamp the leaflet between the end portion 92 and the
second side of the body 72.
[0094] Because the anchor 74 extends around the ventricular end 78
of the body, the first portions 84, 86 can be provided with a
larger radius of curvature compared to if the anchor 74 was
connected to the body 72 on the same side as the end portion 92.
This large radius of curvature of the first portions 84, 86 can
provide greater control over the clamping forces between the end
portion 92 and the body 72, and provide a more robust and durable
anchor configuration, reducing stress concentrations in the anchor
74 and connection points 80, 82. Because the body is acting as a
spacer, causing the blood to flow around it, the anchor 74 can pass
around the ventricular end 78 of the body without obstructing the
flow of blood any more than necessary. Having the anchor members
84, 86 positioned below the ventricular end of the body may not be
as desirable in embodiments where the body comprises an annular
frame with a prosthetic valve within the annular frame, since the
members 84, 86 could restrict the flow of blood through the body to
some degree.
[0095] In the case of the device 70, when the device is clipped
onto a mitral leaflet between the end portion 92 and the second
side of the body 72, a majority of the blood flow passes around the
other three sides of the body (i.e., the left, right, and bottom
side in FIG. 18). This is illustrated in FIG. 21, which shows a
ventricular end view of the device 70 implanted in a mitral orifice
with the posterior leaflet 8 captured between the anchor 74 and the
body 72. The anterior leaflet 6 is opened away from the body 72 in
FIG. 21, allowing blood to flow around three sides of the body
during diastole. As shown in FIG. 21, the first members 84, 86 of
the anchor 74 extend across the body without blocking the flow of
blood around the body. Though not shown, during systole, the
anterior leaflet 6 can close around the body 72 and create a seal
with the body and the side portions of the posterior leaflet 8 to
prevent regurgitation into the left atrium 2. The body 72 is shown
in FIG. 21 covered with the blood-impervious fabric 94 that extends
around the atrial end 76 of the body and is open on the ventricular
end 78 of the body, preventing blood from flowing through the body
72. In some embodiments, the ventricular end 72 can also be covered
by the fabric to fully enclose the body and provide improved
hemodynamics.
[0096] The exemplary prosthetic devices disclosed herein can be
delivered to the mitral region via plural different approaches.
FIG. 22 shows an exemplary prosthetic device 100 having a single
anchor 102, being delivered with a catheter 104 via an exemplary
transeptal atrial approach. In the approach shown in FIG. 22, the
catheter 104 passes through the inferior vena cava 110, the right
atrium 112, and through an incision made in the septum 114, to
reach the left atrium 2. The distal end portion 106 of the catheter
104 serves as a sheath for containing the prosthetic device 100 in
a compressed state during delivery to the heart. The delivery
apparatus can further include a pusher member 116 extending
coaxially through the catheter 104. Once the catheter enters the
left atrium 2, implantation of the device 100 can be performed
similar to the methods described in relation to FIGS. 11-21 herein.
Alternatively, the prosthetic devices described herein can be
implanted via an atrial approach using any of the methods and/or
devices described in U.S. Patent Application Publication No.
2011/0137397 in relation to FIGS. 63-67 thereof, or in U.S.
Provisional Patent Application No. 61/760,577.
[0097] FIG. 23 shows an exemplary prosthetic device 120 having a
single anchor 122, being delivered with a delivery device 124
through the apex 126 of the heart in an exemplary transapical
approach. In the transapical approach shown in FIG. 23, the
prosthetic device 120 is held in a compressed configuration in a
distal end of the delivery device 124 as the delivery device is
inserted through an incision in the heart apex 126 and delivered
through the left ventricle 4 to the mitral region. The delivery
device 124 can have features that allow the anchor 122 to radially
expand out of the delivery device 124 and away from the
still-compressed body of the prosthetic device 120, as shown in
FIG. 23, to capture one of the native mitral leaflets 6 or 8. For
example, the delivery device 124 can have an outer sheath
configured to release the anchor 122 while the body of the
prosthetic device is held in a compressed state in an inner sheath,
such as by providing a slot in the distal end portion of sheath 124
through which the anchor 122 can extend. In some embodiments, the
delivery device 124 can be similar to the delivery device 2000
described in U.S. Patent Application Publication No. 2011/0137397
(for example, with only one of the slots 2028 instead of two), and
can be used to implant the prosthetic device 120 via methods
similar to those described therein in relation to FIGS. 49-62
thereof. The delivery device 124 can also be similar to the
delivery devices described in U.S. Provisional Patent Application
No. 61/760,577, and can be used to implant prosthetic devices via
methods similar to those described therein.
[0098] FIG. 24 shows an exemplary prosthetic device 200 that is
configured to inflate with blood and expand radially during systole
and to collapse radially during diastole. The device 200 can
comprise a structural portion 202, an anchor 204, and an inflatable
portion, or parachute, 206 having an annular cross-sectional
profile. The structural portion 202 can comprise a rigid member or
frame that supports one side of the parachute 206. The anchor 204
can comprise an extension of the structural member 202 or a
separate member coupled to the structural member and is configured
to attach the device 200 to one of the native mitral leaflets, such
as the posterior native leaflet as shown in FIG. 24, by capturing
the leaflet between the anchor 204 and the structural portion 202.
The parachute 206 can comprise a flexible, blood-impermeable
material, such as PET fabric or the like. The parachute 206 has an
open lower end 208 and a closed upper end 210.
[0099] During systole, as illustrated in FIG. 24, higher pressure
in the left ventricle relative to the left atrium forces blood from
the left ventricle into the open lower end 208 of the parachute.
The increased pressure in the parachute (labeled P.sub.2 in FIG.
24) exceeds the pressure in the left atrium (labeled P.sub.1 in
FIG. 24), causing the parachute to inflate with blood and to expand
radially and upwardly. At the same time, the native leaflets 6, 8
are caused to collapse toward each other. The device 200 moves
along with the leaflet to which it is attached and the other
leaflet moves toward the expanding parachute 206. When fully
inflated, the parachute 206 can seal the gap between the two native
mitral leaflets 6, 8 and prevent or reduce mitral
regurgitation.
[0100] During diastole (not shown), P.sub.1 exceeds P.sub.2 causing
the parachute 206 to deflate and collapse toward the structural
portion 202. At the same time, the two native leaflets 6, 8 are
pushed apart. This allows blood to flow from the left atrium to the
left ventricle with minimal obstruction by the collapsed parachute
206.
[0101] In some embodiments, the device 200 can comprise additional
structural elements. For example, some embodiments can comprise
longitudinal splines that extend from the upper end 210 to the
lower end 208 to provide longitudinal rigidity to the parachute
without impeding expansion/contraction in the radial direction,
much like a common umbrella. In some embodiments, the device 200
can comprise a structural member at the lower opening 208 to
prevent the lower opening from fully closing during diastole, such
that blood can more easily enter the lower opening at the beginning
of systole. In some embodiments, the device 200 can comprise a
biased portion that urges the lower opening 208 toward an opened
position. The biased portion can comprise a spring mechanism,
resiliently flexible members, or other mechanisms. In some
embodiments, the device 200 can further comprise an atrial portion
that extends from or adjacent to the upper end 210 and contacts the
atrial walls and/or the atrial side of the leaflet to which the
device is attached. The atrial body can help secure the device
within the mitral orifice and can prevent movement toward the left
ventricle. The atrial body can comprise a separate component or an
extension of the structural member 202. The atrial body can be
configured like the atrial bodies 26A, 26B or 26C described above,
or can have other configurations.
[0102] FIGS. 25-28 show a prosthetic spacer 220 according to
another embodiment, wherein the spacer 220 is coupled to one of the
native leaflets using, for example, sutures. The spacer 220 can be
formed from any of various suitable materials, including
bio-compatible materials such as pericardial tissue, polymers,
sponge, or a gel or saline filled structure such as a balloon. The
material composition of the spacer 220 can be selected to increase
desirable characteristics of the spacer 220, such as performance,
durability, promotion of native tissue growth, etc. The spacer 220
can be formed in any of various suitable shapes, such as a
rectangle, a semi-elliptical ring or generally u-shape, or a
semi-ellipse. As shown in FIG. 25, the spacer 220 can be sutured to
the posterior leaflet 8 using sutures 222 via a transeptal
approach, and as shown in FIG. 26, the spacer 220 can be sutured to
the posterior leaflet 8 using sutures 222 via a transapical
approach. In use, the opposite leaflet (the anterior leaflet in the
illustrated embodiment) can coapt against the spacer 220 to prevent
or minimize regurgitation.
[0103] FIG. 27 shows the spacer 220 after it has been sutured to
the native posterior leaflet 8. As shown, two sutures 222 can be
sufficient to couple the spacer 220 to the leaflet 8. The sutures
222 can be positioned as shown, with one suture 222 at either end
of the spacer 220, which spans across the leaflet 8. In alternative
embodiments, additional or fewer sutures can be used, and the
sutures can be situated in alternative locations on the spacer 220
and/or on the leaflet 8.
[0104] FIG. 28 shows the spacer 220 being coupled to the posterior
native leaflet 8 using a length of elongated material 224 and a
pair of slidable locking devices 226. The elongated material 224
can comprise, for example, a length of thread or suture material,
or a metal or polymeric wire, or other material suitable for
suturing, such as biological tissue. In the illustrated embodiment,
a single strand of material 224 is used, although in alternative
embodiments, two or more strands 224 can be used to couple the
spacer 220 to the native leaflet 8. In order to couple the spacer
220 to the native posterior leaflet 8, one or both of the slidable
locking devices 226 can be guided along the strand of material 224
toward the native leaflet 8, thereby decreasing the length of the
strand 224 between the locking devices 226 until the spacer 220 is
held firmly against the leaflet 8 in a desired deployed
configuration. Because the locking devices 226 are positioned
behind the posterior leaflet 8 in this configuration (that is, they
are located between the native leaflet 8 and the wall of the left
ventricle 4), the potential for interference between the locking
devices 226 and the coaptation area of the leaflets 6, 8 is
minimized. Once the spacer 220 is situated in this configuration,
any excess material 228 can be trimmed to prevent interference of
the material 224 with the operation of the heart valve. The locking
devices 226 can be configured to be slid or passed over a suture in
one direction and resist movement in the opposite direction.
Examples of locking devices (also referred to as suture securement
devices) that can be implemented in the embodiment of FIG. 28 are
disclosed in co-pending application Ser. No. 13/938,071, filed Jul.
9, 2013, which is incorporated herein by reference.
[0105] FIGS. 25-28 show one spacer 220 coupled or secured to the
posterior leaflet 8. In alternative embodiments, a spacer 220 can
be coupled as described above to the anterior leaflet 6 in place of
or in addition to the spacer 220 coupled to the posterior leaflet
8. Except where physically impossible, any of the embodiments
described herein can be sutured to native tissue as described above
with reference to spacer 220, rather than or in addition to being
clipped to the native leaflets using one or more anchors.
[0106] By anchoring a prosthetic mitral device to one of the mitral
leaflets, as disclosed herein, instead of anchoring the device to
the walls of the left ventricle, to the walls of the left atrium,
to the native valve annulus, and/or the annulus connection portions
of the native leaflets, the device anchorage is made independent of
the motions of the ventricular walls and atrial walls, which move
significantly during contractions of the heart. This can provide a
more stable anchorage for a prosthetic mitral device, and eliminate
the risk of hook-type or cork screw-type anchors tearing or
otherwise causing trauma to the walls of the left ventricle or left
atrium. Furthermore, the device body can be held in a more
consistent position with respect to the mitral leaflets as the
leaflets articulate, eliminating undesirable motion imparted on the
device from the contraction motions of the left ventricle walls and
left atrium walls. Anchoring to a mitral leaflet can also allow for
a shorter body length compared to devices having other anchorage
means.
Leaflet Extension
[0107] FIG. 29 shows another exemplary prosthetic device 300
implanted at the mitral valve region for treating regurgitation.
The device 300 comprises a strong, flexible sheet of
blood-impermeable material. The device 300 has an upper end 302
that is secured to the mitral annulus and/or the region of a mitral
valve leaflet adjacent to the mitral annulus. The portion of the
device 300 extending away from this upper end portion 302 is a free
end portion of the device 300. In the illustrated example, the
upper end 302 is attached to the mitral annulus above the posterior
leaflet 8. In other examples, the arrangement can be reversed with
the device 300 secured to the anterior leaflet 6. The device 300
can be secured to the native tissue by various means, such as via
suturing or via barbed anchors or microanchors 304. The upper end
302 of the device 300 can be wider than the free end portion of the
device 300, thus the device 300 can have a generally trapezoidal
shape.
[0108] In FIG. 29, the lower end of the anterior leaflet 6 is not
shown in order to show the lower end of the posterior leaflet 8 and
the lower end 306 of the device 300 extending downwardly through
the mitral orifice and into the left ventricle 4. The lower end 306
of the device can be shorter, longer, or about the same length as
the leaflet to which it is attached. As shown in FIGS. 30 and 31,
the lower end 306 of the device in the illustrated embodiment
extends below the lower end of the posterior leaflet during
diastole (FIG. 31), and extends short of the lower end of the
anterior leaflet 6 during systole (FIG. 30). The lower end 306 can
be tethered to a location in the left ventricle 4. For example, the
lower end 306 can be tethered to the papillary muscle heads 310 via
tethers 308 and anchors 312, as shown, (in a manner similar to the
way in which the native chordae tendineae 314 tether the native
leaflet 8 to the papillary muscles 310), or can be tethered to the
apex of the left ventricle.
[0109] During systole, as shown in FIG. 30, the device 300 inflates
or fills with blood from the left ventricle 4 and expands laterally
toward the anterior leaflet 6. This causes the lower portion of the
device 300 to seal against the anterior leaflet 6, blocking the
flow of blood back into the left atrium 2. The lateral edges of the
device 300 can seal between the two native leaflets adjacent to the
commissures where the native leaflets still naturally coapt with
each other. The tethers 308 prevent the lower end 306 of the device
300 from moving toward and/or into the left atrium 2 and thereby
breaking the seal with the anterior leaflet 6. Thus, the device 300
augments the native posterior leaflet and helps seal the mitral
orifice in the case where the native leaflets 6, 8 do not otherwise
not fully coapt and allow regurgitation between them.
[0110] During diastole, as shown in FIG. 31, high pressure in the
left atrium 2 forces the device 300 to collapse against the
posterior leaflet 8, allowing blood to flow into the left ventricle
4 with minimal obstruction from the device 300.
[0111] FIG. 32 shows another exemplary prosthetic device 400
implanted at the mitral valve region for treating mitral
regurgitation. The device 400 comprises a rigid frame 402 (e.g., a
metal frame) that clips around the posterior leaflet 8 with an
anchor portion 404 being positioned behind the posterior leaflet 8
and an atrial portion 406 being positioned along the atrial surface
of the mitral annulus and/or the portion of the posterior leaflet
adjacent to the annulus. The frame 402 can secure the device 400 to
the posterior leaflet 8 without sutures or other tissue puncturing
elements like the anchors 304 in FIGS. 29-31. The device 400 also
can be implanted on the anterior leaflet 6. The device 400 further
comprises a strong, flexible sheet 408 of blood-impermeable
material, like the device 300. An upper end 410 of the sheet 408
can be secured to the frame 402 at or near the atrial portion 406.
The portion of the sheet 408 extending away from this upper end
portion 410 is a free end portion of the sheet 408.
[0112] In FIG. 32, the lower end of the anterior leaflet 6 is not
shown in order to show the lower end of the posterior leaflet 8 and
the lower portions of the device 400 extending downwardly through
the mitral orifice and into the left ventricle 4. The lower end 412
of the sheet 408 can be shorter, longer, or about the same length
as the lower end of the leaflet to which it is attached. As shown
in FIGS. 33 and 34, the lower end 412 of the sheet 408 in the
illustrated embodiment extends below the lower end of the posterior
leaflet during diastole (FIG. 34), and extends short of the lower
end of the anterior leaflet 6 during systole (FIG. 33). The lower
end 412 can be tethered to a location in the left ventricle 4
and/or can be tethered to one or more points 420 near the lower end
of the frame 402 (both tethering means are shown in FIGS. 33 and
34, though one can be used without the other). For example, in some
embodiments, the lower end 412 of the sheet 408 can be tethered to
the papillary muscle heads 416 via tethers 424 and anchors 426 (in
a manner similar to the way in which the native chordae tendineae
414 tether the native leaflet 8 to the papillary muscles 416),
and/or can be tethered to the apex of the left ventricle 4. In
other embodiments, the sheet 408 is tethered only to the frame 402
and tethers extending down into the left ventricle 4 are optional.
In such embodiments, one or more tethers 428 can extend from
adjacent the lower end 412 of the sheet, such as from the lower
lateral corners 422, and attach to the lower end of the frame at or
near points 420. In some embodiments, the sheet 408 can adopt a
three dimensional curvature when inflated, with the lower corners
being held closer to the lower end of the frame 402 while an
intermediate portion of the lower edge 412 is allowed to billow out
(somewhat like a spinnaker sail) further toward the anterior
leaflet 6 to create a seal.
[0113] During systole, as shown in FIG. 33, the sheet 408 inflates
or fills with blood from the left ventricle 4 and expands laterally
toward the anterior leaflet 6. This causes the lower portion of the
sheet 408 to seal against the anterior leaflet 6, blocking the flow
of blood back into the left atrium 2. The lateral edges of the
sheet 408 can seal between the two native leaflets adjacent to the
commissures where the native leaflets naturally coapt with each
other. Thus, the device 400 augments the native posterior leaflet
and helps seal the mitral orifice in the case where the native
leaflets 6, 8 do not otherwise not fully coapt and allow
regurgitation between them.
[0114] During diastole, as shown in FIG. 34, high pressure in the
left atrium 2 forces the sheet 408 to collapse against the
posterior leaflet 8, allowing blood to flow into the left ventricle
4 with minimal obstruction from the device 400.
[0115] FIGS. 35 and 36 show embodiments of prosthetic devices 460,
470 which can be used to extend the effective length of the native
leaflets 6, 8. As shown in FIG. 35, a prosthetic device 460 can
include a body 462 and a clip 464 for clipping the device 460 to
one of the anterior or posterior native leaflets 6, 8. As shown in
FIG. 36, a prosthetic device 470 can include a body 472 and one or
more sutures 474 for coupling the device 470 to one of the anterior
or posterior native leaflets 6, 8. In use, the devices 460, 470
have free end portions extending away from the native leaflets
which extend the effective length of the native leaflets, thereby
increasing the chance of and extent of coaptation between them, as
described more fully below. The bodies 462, 472 can comprise a
material which is stiff enough to reduce the chance of leaflet
prolapse, and flexible enough to increase the extent of leaflet
coaptation. Suitable materials can include, for example, biological
materials such as pericardial tissue, goretex, silicone,
polyurethane, or other polymeric materials. FIG. 35 shows that a
device 460 can be used on each of the anterior and posterior native
leaflets 6, 8, and FIG. 36 shows that a device 470 can be used on
each of the anterior and posterior native leaflets 6, 8, but in
alternative embodiments, only one such device can be used, or one
device 460 and one device 470 can be used. FIG. 35 shows that
tethers 461 can be used to tether free end portions of the bodies
462 to locations in the left ventricle, thus reducing the chances
of prolapse of the prosthetic devices 460 during systole. The
tethers 461 are optional, and can be used in a similar fashion in
combination with the devices 470, 500, 502, or any other suitable
devices described herein.
[0116] FIG. 37 shows exemplary prosthetic devices 500, 502 which
combine features of the prosthetic spacers and the leaflet
extensions described above. Prosthetic device 500 is shown coupled
to the posterior native leaflet 8 while the prosthetic device 502
is shown coupled to the anterior native leaflet 6. The prosthetic
devices 500, 502 include relatively thick upper portions 504, 506,
which function in a manner similar to the prosthetic spacers
described above, and relatively thin, elongate free end portions
508, 510, which function in a manner similar to the devices 300,
400, described above. The free end portions 508, 510 can have
respective distal end portions 514, 516, which represent the
effective distal ends of the extended leaflets.
[0117] In use, the free end portions 508, 510 extend the effective
length of the respective leaflets, and can facilitate initiation of
leaflet coaptation during ventricular systole. During systole, the
leaflets are urged toward one another due to the pressures extant
in the left ventricle and left atrium. Due to the extended
effective length of the leaflets, the end portions 514, 516 are
more likely to coapt than were the ends of the native leaflets
without the extensions. Once coaptation is initiated, and thus
blood flow from the left ventricle to the left atrium at least
partially impeded, the pressure in the left ventricle can increase,
further increasing the pressure differential between the left
ventricle and the left atrium and urging the leaflets 6, 8, further
toward one another.
[0118] As a result, the portions of the leaflets 6, 8, and their
respective extensions 502, 500 which coapt, increases (both in the
direction from the end portions 514, 516 toward the left atrium 2,
and from the locations of the devices 500, 502, toward the
commissure points of the mitral valve), leading to a cycle of
increasingly impeded blood flow, increased pressure differential,
and increased coaptation of the leaflets. Thus, by facilitating
initiation of coaptation, the free end portions 508, 510 can help
to reduce regurgitation of blood from the left ventricle to the
left atrium during ventricular systole. Further, the upper portions
504, 506 can further help to prevent regurgitation in the manner
described above with respect to prosthetic device 10. In cases
where the native leaflets 6, 8, do not experience sufficient
coaptation to prevent regurgitation, the relatively thick upper
portions 504, 506, can help to increase their coaptation and
thereby reduce regurgitation.
[0119] FIG. 37 shows that the devices 500, 502 can be sutured to
the native leaflets 8, 6, with sutures 512, but in alternative
embodiments, the devices 500, 502 can be clipped to the native
leaflets 8, 6, as described above. In alternative embodiments, only
one of the devices 500, 502 can be used rather than both.
Spacers Having Plural Anchors
[0120] In some embodiments, prosthetic devices can include a body
and a plurality of anchors such that the body can be clipped to
more than one leaflet. Such embodiments can be used to effectively
couple two or more leaflets to one another. Thus, such a device can
be used to bring native leaflets closer to one another and restrict
their mobility in order help increase the chance of or extent of
coaptation between the leaflets.
[0121] FIGS. 38-41 show a prosthetic spacer 600 having a body 602,
a first anchor 604 and a second anchor 606. The body 602 and
anchors 604, 606 can be fabricated from any of various suitable
materials, and the body is desirably made from a relatively
compressible material so that its profile can be reduced for
delivery into a patient's heart within a delivery catheter.
Alternatively, the body 602 can be inflatable (e.g., to be inflated
with a fluid such as saline or a curing epoxy or polymer) or
otherwise expandable (e.g., it can be fabricated from a frame
comprising a self-expanding material such as Nitinol) such that the
cross section of the body 602 can be reduced for delivery into a
patient's heart and then expanded to a final, deployed
configuration therein. An inflatable spacer can be particularly
advantageous because it can allow enhanced customization of the
spacer, and can allow fine control over the final, deployed size
and configuration of the spacer.
[0122] FIGS. 38 and 39 show that the anchors can have similar
structures. Each anchor 604, 606 can be made from a single piece of
relatively rigid metallic material (e.g., an elongated wire) which
can include first and second inner portions 608, 610, first and
second bottom portions 612, 614, and a main loop portion 616
extending between and connecting the upper ends of the bottom
portions 612, 614. The inner portions 608, 610 can be coupled
rigidly to the inside of the body 602. The inner portions 608, 610
can extend downwardly out of the lower end of body 602 to the
respective bottom portions 612, 614, which can each curve upwardly
around the lower end of the body 602 to meet the main loop portion
616.
[0123] FIGS. 39 and 40 show that the structure of the anchors 604,
606, and their connections to the body 602, biases the main loop
portions 616 of the anchors 604, 606, into contact with the sides
of the body 602. Thus, in use, the spacer 600 can be clipped to the
anterior and posterior native leaflets 6, 8, with one of the
leaflets 6, 8 clipped between the anchor 604 and the body 602, and
the other of the leaflets 6, 8, clipped between the anchor 606 and
the body 602. FIG. 41 shows that the anchors 604, 606 can be
splayed apart so that gaps exist between the anchors 604, 606, and
the body 602. Thus, the spacer 600 can be introduced into the
region of a patient's native mitral valve in a closed configuration
with the anchors 604, 606 against the side of the body 602 (FIGS.
38-40). The anchors 604, 606 can then be splayed apart or expanded
into an open configuration (FIG. 41) so the spacer can be
positioned with the native leaflets 6, 8, in the gaps between the
anchors 604, 606 and the body 602, after which the anchors 604, 606
can be allowed to return to the closed configuration under their
own resiliency to capture the leaflets 6, 8, and clip the spacer
600 thereto.
[0124] FIG. 42 shows that in use, the prosthetic spacer 600 can be
clipped to the posterior native mitral valve leaflet 8 using the
first anchor 604, as described above with regard to prosthetic
spacer 10 and shown in FIG. 1, and can be clipped to the anterior
native mitral valve leaflet 6 using the second anchor 606, as
described above with regard to prosthetic spacer 10 and shown in
FIG. 2. FIG. 43 shows that when the prosthetic spacer 600 is
clipped to both of the leaflets 6, 8, (e.g., at the A2 and P2
regions of the leaflets, as identified by Carpentier nomenclature)
it brings them together, decreasing the overall area of the mitral
valve orifice, and dividing the mitral valve orifice into two
orifices 618, 620 during diastole. Thus, the area through which
mitral regurgitation can occur is reduced, leaflet coaptation can
be initiated at the location of the spacer 600, and the leaflets
can fully coapt more easily, thereby preventing or minimizing
mitral regurgitation.
[0125] FIGS. 44 and 45 show alternative embodiments of dual anchor
spacers clipped to the A2 and P2 regions of the anterior and
posterior native leaflets 6, 8, as viewed from the left atrium.
FIG. 44 shows an embodiment 640 in which the shape of the body of
the spacer 640 is relatively elongate such that the spacer 640
extends substantially between the commissures 650, 652 of the
mitral valve. As shown, in this embodiment, the native leaflets 6,
8 are brought toward one another by the anchors of the spacer 640,
the overall area of the valve orifice is reduced, and the orifice
is divided into four orifices 642, 644, 646, 648 during diastole.
Thus, the area through which mitral regurgitation can occur is
reduced, leaflet coaptation can be initiated at the location of the
spacer 640, and the leaflets can fully coapt more easily, thereby
preventing or minimizing mitral regurgitation. In addition, the
shape of the spacer 640 can more effectively treat eccentric jet
mitral regurgitation, because the extension of the body of the
spacer 640 to the commissures 650, 652 helps the leaflets 6, 8, to
coapt across the entirety of the native mitral valve orifice.
[0126] FIG. 45 shows an embodiment of a dual-anchor spacer 660 in
which the body of the spacer 660 comprises a prosthetic valve
having one or more flexible leaflets 666 that permit blood to flow
into the left ventricle during diastole and block the back flow of
blood into the left atrium during systole. In this embodiment, the
native leaflets 6, 8 are brought closer to one another and the
native mitral valve orifice is divided into two orifices 662, 664
during diastole. Because the body of the spacer 660 comprises a
prosthetic valve, rather than a solid piece of material, the total
effective open area between the leaflets during diastole (e.g., the
area through which blood can flow) is greater in this embodiment
than in the embodiment illustrated in FIGS. 43 and 44.
[0127] In alternative embodiments, the body of a dual anchor spacer
can have various alternative shapes. For example, cross-sectional
profile of the body can be circular, elliptical, or as shown in
FIG. 46, can have a generally crescent shape. A spacer body having
a crescent shape such as spacer body 680 in FIG. 46 (viewed from
the left atrium) can be particularly advantageous because it can
conform to the overall crescent shape of the anterior and posterior
leaflets 6, 8 of the native mitral valve. In such an embodiment,
the concave side 682 of the crescent shaped body 680 can face the
anterior native leaflet 6 while the convex side 684 of the crescent
shaped body 680 can face the posterior native leaflet 8. FIG. 46
shows that in such an embodiment, the native mitral valve orifice
can be divided into two orifices 686, 688, each on the concave side
682 of the spacer 680, as the convex side 684 can conform to the
posterior native leaflet 8 such that no openings exist between
them.
[0128] FIGS. 47-51 show embodiments of spacers having three
anchors, which can be clipped to leaflets in the tricuspid valve of
the human heart in a manner similar to that described above with
regard to spacers in the mitral valve. FIG. 47 shows a tricuspid
spacer 700 having a circular body 712 and three anchors 702. FIG.
48 shows the spacer 700 implanted in the tricuspid valve (as viewed
from the right ventricle, as blood is being pumped out of the right
ventricle), with each of the three anchors 702 clipped to a
respective leaflet 704 of the tricuspid valve, and thereby coupling
them to one another. FIG. 49 shows the spacer 700 clipped to the
leaflets 704 of the tricuspid valve as blood is pumped from the
right atrium to the right ventricle through orifices 706, 708, 710.
FIG. 50 shows an alternative tricuspid spacer 720 having a body 722
and three clips 724. As shown, the body 722 can have a generally Y
shape. FIG. 51 shows an alternative tricuspid spacer 730 having a
body 732 and three clips 734. As shown, the body 732 can have a
generally triangular shape.
[0129] FIGS. 52-54 show an exemplary dual anchor spacer 750 having
a body 752 and first and second anchors 754, 756, positioned within
a native mitral valve. FIG. 52 shows the spacer 750 as seen from
the left ventricle 4. FIG. 53 shows the spacer 750 as viewed from
the left atrium 2 during systole, and FIG. 54 shows the spacer 750
from the left atrium 2 during diastole. As can be seen in FIG. 53,
no openings appear through which regurgitant flow can occur. As can
be seen in FIG. 54, two openings 758, 760 exist through which blood
can flow from the left atrium 2 to the left ventricle 4 during
diastole, as is desirable.
[0130] A suitable delivery sequence for delivering a prosthetic
spacer such as spacer 750 to the mitral valve region of a patient's
heart can comprise compressing a spacer to a compressed, delivery
configuration, delivering the spacer to the coaptation line of a
patient's native mitral valve, expanding the spacer until
regurgitation in the patient's mitral valve is adequately reduced
(an inflatable device can allow a physician to make fine
adjustments to the final size and configuration of the spacer based
on information received during the delivery process), manipulating
the anchors of the spacer to an open position, capturing the native
leaflets between the anchors and the body of the spacer, and then
manipulating the anchors to a closed position, thereby clipping the
spacer to the native mitral valve leaflets.
[0131] FIGS. 55 and 56 show an exemplary dual anchor spacer 800
comprising a main body 802 and first and second anchors 804, 806.
The main body 802 can comprise a plurality of interconnected struts
808 which together form a plurality of open cells and are arranged
to form a generally annular shape having first and second end
portions 816, 818. The body 802 can be formed to be radially
self-expandable. For example, the body 802 can be fabricated from a
shape-memory material such as Nitinol, which can allow the spacer
800 to be radially compressed to a compressed delivery
configuration, delivered to one of a patient's native heart valves,
then self-expanded to an expanded functional configuration for use
within the patient's heart.
[0132] The first anchor 804 can comprise first and second end
portions 810, 812 which can be coupled to the first end portion 816
of the main body 802, and a loop portion 814 which can extend
between the first and second end portions 810, 812. The first and
second end portions 810, 812 can extend away from the first end
portion 816 of the body 802, then curl back and extend toward the
second end portion 818 of the main body 802. The loop portion 814
can be coupled to the first end portion 810, extend generally
toward the second end portion 818 of the main body 802, curl back
and extend toward the first end portion 816 of the main body 802,
and be coupled to the second end portion 812.
[0133] Thus, the first anchor 804 can be coupled to the first end
portion 816 of the main body 802 and extend along the side of the
main body 802 toward its second end portion 818. The second anchor
806 can have a similar structure, and can be coupled to the main
body 802 such that it extends along an opposing side of the main
body 802. In this embodiment, the spacer 800 can be clipped to
native tissues by pinching the native tissues between the anchors
804, 806 and the respective sides of the main body 802. The anchors
804, 806 can be made from various suitable materials, and in one
exemplary embodiment can be fabricated from the shape-memory
material Nitinol. The anchors 804, 806 in the illustrated
embodiment are fabricated from separate pieces of material from the
main body 802, and are coupled to the main body 802 using coupling
mechanisms 820. The coupling mechanisms 820 can be, for example,
crimping rings that extend around a strut at the first end 816 of
the main body 802 and an adjacent portion of an anchor. In
alternative embodiments, however, the anchors 804, 806 and the main
body 802 can be fabricated integrally with one another (i.e., from
a single piece of material). As best shown in FIG. 56, the main
body 802 can have a generally elliptical or oval shape when viewed
on end, but in alternative embodiments, the main body can be formed
to have any of various suitable shapes when viewed on end, such as
a circle.
[0134] FIGS. 57 and 58 show the spacer 800 covered in a blood
impermeable fabric material 822, such as made of polyethylene
terephthalate (PET) or polyurethane The fabric material 822 can be
relatively thick, strong, and soft, such as a knitted lofty cloth.
The fabric material 822 can be selected to provide a softer surface
for contact with the native tissue, thus reducing trauma caused to
the native tissues by the implantation of the spacer 800, can be
selected to promote native tissue ingrowth into the spacer 800,
and/or can be selected to improve the seal formed between native
tissues and the portions of the spacer 800 they come into contact
with. Additionally, FIG. 58 shows that a fabric layer 824 can be
disposed to cover all or substantially all of the opening at the
center of the main body 802. The layer 824 can be blood
impermeable, thereby blocking the flow of blood through the spacer
800. The layer 824 can be formed from the same material as fabric
822, and together the fabric 822 and layer 824 can work to prevent
the regurgitant flow of blood through a heart valve when the spacer
has been implanted therein.
[0135] FIGS. 59-63 illustrate exemplary systems and methods which
can be used to implant the spacer 800 in a native heart valve.
FIGS. 59-61 illustrate exemplary systems and steps which can be
used to crimp the spacer 800 to a compressed, delivery
configuration, suitable for delivery to a patient's native heart
valve within a delivery device 850. FIG. 59 shows the spacer 800
with its main body 802 positioned in a crimper mechanism 900
capable of crimping the main body 802 to a compressed
configuration. As shown, the anchors 804, 806 can remain outside
the crimper mechanism 900 as it is used to crimp the main body
portion 802. For example, U.S. Pat. No. 7,530,253, which is hereby
incorporated herein by reference, describes an exemplary prosthetic
valve crimping device that can be used to crimp the spacer 800.
[0136] In some embodiments, the delivery device 850 can be similar
to the delivery device 2000 described in U.S. Patent Application
Publication No. 2011/0137397 or the delivery devices described in
U.S. Provisional Patent Application No. 61/760,577, and can be used
to implant prosthetic devices via methods similar to those
described therein. FIG. 59 shows that the delivery device 850 can
include an inner sheath 852 provided with a pair of slots 854
disposed on opposing sides of the inner sheath 852, and an internal
locking element 856, which is axially adjustable relative to the
inner sheath 852 along a central longitudinal axis of the inner
sheath 852. The internal locking element 856 can comprise a
generally cruciform shape, having four extension portions 858
between which are defined four voids 860. As best shown in FIG. 59,
two of the voids 860 can be aligned with the two slots 854, which
can also be aligned with the portions of the anchors 804, 806 which
are coupled to the body 802 of the spacer 800. Thus, in this
embodiment, the locking element 856 can be retracted into the inner
sheath 852, thereby pulling the main body portion 802 of the spacer
800 into the inner sheath 852 in the same direction. As best shown
in FIG. 60, as the spacer 800 is pulled into the inner sheath 852,
the first and second end portions 810, 812 of each of the anchors
extend from the first end portion 816 of the spacer 800, through
the respective voids 860 in the locking element, and then curl out
of the slots 854 in the sides of the inner sheath 852, extending
along the sides of the body 802 toward the second end portion 818
of the main body 802. In this way, the body 802 of the spacer 800
can be pulled into the inner sheath 852 and thereby compressed to a
compressed delivery configuration.
[0137] As shown in FIG. 61, after the main body portion 802 has
been situated within the inner sheath 852, an outer sheath 862 can
be extended toward the distal end of the device 850 so as to
enclose the anchors 804, 806, thereby causing them to wrap around
the inner sheath 852 and be confined between the inner sheath 852
and outer sheath 862.
[0138] FIGS. 62 and 63 show a spacer 800 covered in fabric as
described above and situated within a delivery device 870 in two
different configurations. FIG. 62 shows the spacer 800 having its
main body portion 802 situated within an inner sheath 872 of the
delivery device 870 such that the anchors 804, 806 extend toward a
distal end portion of the delivery device 870. In this embodiment,
an outer sheath 874 can be extended distally to retain and secure
the anchors 804, 806 against the sides of the inner sheath 872.
Such a configuration can be used to deliver the spacer
transapically, as described below. In some embodiments, retraction
of the outer sheath 874 can allow the anchors 804, 806 to
self-expand to a splayed-apart configuration.
[0139] FIG. 62 also shows that forcible expanders, or levers, 876
can be used to force the anchors 804, 806 to splay apart. The
forcible expanders 876 can be radially self-expanding levers which
radially self-expand when the outer sheath 874 is retracted or are
otherwise configured to radially expand away from the inner sheath
when they are actuated by a physician (such as by actuating a
control knob on a handle that is operatively connected to the
expanders 876). The expanders 876 can alternatively be sutures or
other mechanisms which can be actuated by a physician to force the
anchors 804, 806 to splay apart. In some embodiments, retraction of
the outer sheath 874 can allow the anchors 804, 806 to self-expand
to a first splayed-apart configuration, and forcible expanders 876
can be actuated to force the anchors 804, 806 to further radially
expand to a second splayed-apart configuration. In such an
embodiment, the expanders 876 can be actuated to cause the anchors
804, 806 to radially expand to the second splayed apart
configuration, and can then be actuated to allow the anchors 804,
806 to move radially inward and return to the first splayed-apart
configuration.
[0140] FIGS. 62 and 63 illustrate the spacer 800 situated within
the delivery system 870 such that the anchors 804, 806 extend
generally along the outside of the body 802 toward the second end
portion 818 of the spacer 800. In alternative embodiments, however,
the configuration of the body 802 and anchors 804, 806 within the
delivery system 870, and the deployment of the spacer 800 from the
delivery system 870, can be similar to that illustrated in FIGS.
12-15 with respect to device 50 and delivery catheter 56.
[0141] FIG. 63 shows the spacer 800 having its main body portion
802 situated within the inner sheath 872 of the delivery device 870
such that the anchors 804, 806 extend toward a proximal end portion
of the delivery device 870. In this embodiment, the outer sheath
874 can be extended distally to retain and secure the anchors 804,
806 against the sides of the inner sheath 872. Such a configuration
can be used to deliver the spacer transatrially, as described
below.
[0142] Prosthetic spacers described herein can be delivered using
minimally invasive approaches. FIGS. 64-67 show various approaches
by which a prosthetic spacer 800 can be delivered to the region of
a patient's mitral valve using a delivery system 920. For example,
a prosthetic spacer can be delivered via a transapical approach
(FIG. 64), via a transeptal approach (FIG. 65), via a transatrial
approach (FIG. 66), or via a transfemoral approach (FIG. 67). FIGS.
64-67 show that the delivery system 920 can comprise an outer
sheath 922, an inner sheath 924, and a guidewire 930 which can
extend through the outer sheath 922 and inner sheath 924. The
delivery system 920 can also include a pusher element (not
illustrated in FIGS. 64-67, but similar to those described above),
which can be actuated to move the spacer 800 within the inner
sheath 924. The outer sheath 922, inner sheath 924, guidewire 930,
and pusher element can each be retracted proximally or extended
distally with respect to one another. The guidewire 930 can be used
to guide the delivery of the other components of the system 920 to
an appropriate location within a patient's vasculature. The
guidewire 930 can extend through a small opening or pore in the
spacer 800, for example in the fabric layer 824, the small opening
or pore being small enough that substantial blood cannot flow
therethrough.
[0143] FIGS. 64 and 67 show that the deployment of the spacer 800
to a native mitral valve via the transapical approach can be
similar to the deployment of the valve 800 via the transfemoral
approach, at least because in both cases the valve is delivered to
the mitral valve from the left ventricle. In preparing the delivery
system 920 for delivery of the spacer 800 via the transapical or
the transfemoral approach, the spacer 800 can be situated within
the system 920 with the second end portion 818 of the spacer 800
disposed at the distal end of the system 920 (such as shown in FIG.
62). In the transapical and the transfemoral approaches, the
delivery system 920 can be used to first deliver the spacer 800 to
the region of the native mitral valve from the left ventricle. In
the transapical approach, the delivery device 920 is inserted into
the left ventricle via an opening in the chest and the apex of the
heart. In the transfemoral approach, the delivery device 920 can be
inserted into a femoral artery and advanced through the aorta in a
retrograde direction until the distal end of the delivery device is
in the left ventricle. The outer sheath 922 can then be retracted
proximally such that the anchors 804, 806 are no longer confined
within the outer sheath 922. In some embodiments, the anchors 804,
806 can be configured to self-expand to a splayed apart
configuration shown in FIGS. 64 and 67. In other embodiments, as
described above, the delivery system 920 can include a mechanism
for forcing the anchors 804, 806 to splay apart to the
splayed-apart configuration (such as described above with respect
to the embodiment of FIG. 62).
[0144] The device 920 can then be distally advanced so that the
native mitral valve leaflets are positioned between the splayed
apart anchors 804, 806, and the body 802. The inner sheath 924 can
then be retracted so that the body 802 is no longer confined within
the inner sheath 924 and can radially expand to an expanded
configuration between the native mitral valve leaflets. In some
embodiments, the body 802 can expand such that the native leaflets
are pinched between the body 802 and the anchors 804, 806. In
alternative embodiments, as described above, the mechanism for
forcing the anchors 804, 806 to splay apart can be actuated to
allow the anchors 804, 806 to move radially inward toward the main
body 802, thereby pinching the native leaflets between the main
body 802 and the anchors 804, 806.
[0145] FIGS. 65 and 66 show that the deployment of the spacer 800
to a native mitral valve via the transseptal approach can be
similar to the deployment of the valve 800 via the transatrial
approach, at least because in both cases the valve is delivered to
the mitral valve from the left atrium. In preparing the delivery
system 920 for delivery of the spacer 800 via the transseptal or
the transatrial approach, the spacer 800 can be situated within the
system 920 with the first end portion 816 of the spacer 800
disposed at the distal end of the system 920 (such as shown in FIG.
63). In these approaches, the delivery system 920 can be used to
first deliver the spacer 800 to the region of the native mitral
valve from the left atrium. The outer sheath 922 can then be
retracted proximally such that the anchors 804, 806 are no longer
confined within the outer sheath 922. In some embodiments, the
anchors 804, 806 can be configured to self-expand to a splayed
apart configuration shown in FIGS. 65 and 66. In other embodiments,
as described above, the delivery system 920 can include a mechanism
for forcing the anchors 804, 806 to splay apart to the
splayed-apart configuration.
[0146] The system 920 can then be proximally retracted so that the
native mitral valve leaflets are positioned between the splayed
apart anchors 804, 806, and the body 802. The inner sheath 924 can
then be retracted so that the body 802 is no longer confined within
the inner sheath 924 and can radially expand to an expanded
configuration between the native mitral valve leaflets. In some
embodiments, the body 802 can expand such that the native leaflets
are pinched between the body 802 and the anchors 804, 806. In
alternative embodiments, as described above, the mechanism for
forcing the anchors 804, 806 to splay apart can be actuated to
allow the anchors 804, 806 to move radially inward toward the main
body 802, thereby pinching the native leaflets between the main
body 802 and the anchors 804, 806.
[0147] In any of the four approaches described above, once the
native leaflets have been captured by the spacer 800, the delivery
system 920 can be retracted and removed from the patient's
vasculature. The spacer 800 can remain in the native mitral valve
region, with the main body 802 being situated between the two
native leaflets, thereby helping to reduce or prevent mitral
regurgitation. It will be understood that similar techniques can be
used to deliver a spacer to the native aortic, tricuspid, or
pulmonary valves, depending on the needs of the patient.
[0148] In any of the four approaches described above, a marker
catheter or other similar device can be used to help coordinate
delivery and ensure that a desirable delivery position is achieved.
An exemplary suitable marker catheter can include a standard
catheter designed for angiograms, for example, a catheter made of a
relatively low-density plastic material having relatively
high-density metal marker bands (e.g., radiopaque marker bands)
disposed at regular intervals thereon. Thus, the device can be
introduced into a patient's vasculature and can be viewed under
echocardiography or fluoroscopy. Alternatively, a marker wire can
be used in place of the marker catheter. Another suitable
alternative technique is left atrium angiography, which can help a
physician visualize components of a patient's heart.
[0149] A marker catheter or marker wire can be introduced into a
patient's vasculature and advanced to specific areas of the
vasculature near a patient's heart. For example, a marker catheter
can be advanced from a patient's jugular or femoral vein into the
right atrium, then into the patient's coronary sinus. As another
example, a marker catheter can be advanced from a patient's femoral
artery to the patient's circumflex artery. As another example, a
marker catheter can be advanced into a patient's left atrium. Once
situated in the coronary sinus, circumflex artery, left atrium, or
other suitable area of a patient's vasculature, the marker catheter
can be used to aid a physician in delivering and ensuring desirable
implantation of a prosthetic device. For example, the coronary
sinus extends around the heart near the location and elevation of
the mitral valve and thus can help a physician to properly size and
position a prosthetic device for implantation.
[0150] For example, the patient's vasculature can be viewed under
echocardiography, fluoroscopy, or other visualization technique
which allows a physician to view the prosthetic device being
delivered and the marker catheter. A physician can first view the
devices along an axis extending from the patient's left atrium to
the patient's left ventricle (referred to as a "short axis"). By
viewing the devices along the short axis, a physician can deploy
(such as by inflating a balloon on which an implantable device is
mounted) an implantable prosthetic device and expand portions of
the device to desired sizes and/or configurations based on the size
and location of the marker catheter, which can provide an estimate
of the size of features of the native mitral valve. Alternatively
or additionally, a physician can use the marker catheter to obtain
an estimate of the size of a patient's native heart valve, from
which estimate a prosthetic device to be implanted in the patient's
native heart valve can be selected from a set of devices having
differing sizes, e.g., a set of devices having differing
diameters.
[0151] A physician can also view the devices along an axis
perpendicular to the short axis (referred to as a "long axis"). The
long axis can have several orientations, such as from commissure to
commissure, but in one specific embodiment, the long axis is
oriented from the A2 location to the P2 location of the native
mitral valve. By viewing the devices along the long axis, a
physician can align an implantable prosthetic device relative to
the marker catheter at a desirable location along the short axis,
such that an atrial anchor of the implantable device is situated in
the left atrium (above the marker catheter) and a ventricular
anchor of the implantable device is situated in the left ventricle
(below the marker catheter).
[0152] FIG. 68 shows an exemplary dual anchor spacer 950 which can
be delivered to the region of the native mitral valve via any
suitable delivery method, for example, using the transapical,
transeptal, transatrial, or transfemoral techniques described
above. The spacer 950 can include a main body 952, a first anchor
954, a second anchor 956, and a nosecone 958. The spacer 950 can
also include a tapered portion 962, which can couple the main body
portion 952 to a neck portion 964. The taperer portion 962 can have
a variable width which can taper from the width of the main body
952 to the width of the neck portion 964. The neck portion 964 can
be configured to receive a portion of the nosecone 958 therein, and
can be coupled to the nosecone 958. The main body 952 and anchors
954, 956 can be fabricated from various materials, as described
above with regard to other embodiments, and the nosecone 958 can be
fabricated from various suitable materials such as a long term
implantable silicone or other suitable elastomers.
[0153] The nosecone 958 can have a small pore, or opening, or slit,
966, which can extend through and along the length of the nosecone
958. In accordance with suitable delivery methods making use of a
guidewire such as guidewire 930, the guidewire can extend through
the opening 966, thus eliminating the need for an opening or pore
in a fabric layer. The spacer 950 can facilitate crossing of a
native heart valve due to its tapered tip, which can also provide
improvements in hydrodynamics during diastolic blood flow. When a
guidewire is removed from the opening 966, the opening can close
under its own resiliency and/or blood pressure, thus leaving a
sealed spacer implanted at a native heart valve. Alternatively, or
in addition, the opening 966 can be sufficiently small to prevent
significant amounts of blood from travelling through the nosecone
958.
[0154] The multi-anchor spacers described herein offer several
advantages over previous techniques for treating regurgitation in
heart valves. For example, the multi-anchor spacers described
herein can be used to treat patients whose native leaflets fail to
coapt at all, whereas many previous techniques required some amount
of native coaptation to be efficacious. Additionally, the spacers
described herein (e.g., spacer 640) can treat eccentric jet
regurgitation more readily than other known techniques. While
embodiments have been illustrated with two and three anchors, the
techniques described herein are generally application to spacers
having any number of anchors.
General Considerations
[0155] For purposes of this description, certain aspects,
advantages, and novel features of the embodiments of this
disclosure are described herein. The disclosed methods,
apparatuses, and systems should not be construed as limiting in any
way. Instead, the present disclosure is directed toward all novel
and nonobvious features and aspects of the various disclosed
embodiments, alone and in various combinations and sub-combinations
with one another. The methods, apparatuses, and systems are not
limited to any specific aspect or feature or combination thereof,
nor do the disclosed embodiments require that any one or more
specific advantages be present or problems be solved.
[0156] Although the operations of some of the disclosed methods are
described in a particular, sequential order for convenient
presentation, it should be understood that this manner of
description encompasses rearrangement, unless a particular ordering
is required by specific language. For example, operations described
sequentially may in some cases be rearranged or performed
concurrently. Moreover, for the sake of simplicity, the attached
figures may not show the various ways in which the disclosed
methods can be used in conjunction with other methods. As used
herein, the terms "a", "an" and "at least one" encompass one or
more of the specified element. That is, if two of a particular
element are present, one of these elements is also present and thus
"an" element is present. The terms "a plurality of" and "plural"
mean two or more of the specified element.
[0157] As used herein, the term "and/or" used between the last two
of a list of elements means any one or more of the listed elements.
For example, the phrase "A, B, and/or C" means "A," "B," "C," "A
and B," "A and C," "B and C" or "A, B and C."
[0158] As used herein, the term "coupled" generally means
physically coupled or linked and does not exclude the presence of
intermediate elements between the coupled items absent specific
contrary language.
[0159] In view of the many possible embodiments to which the
principles disclosed herein may be applied, it should be recognized
that the illustrated embodiments are only preferred examples and
should not be taken as limiting the scope of the disclosure.
Rather, the scope is defined by the following claims. We therefore
claim all that comes within the scope and spirit of these
claims.
* * * * *