U.S. patent application number 13/852459 was filed with the patent office on 2013-10-24 for methods, systems and devices for cardiac valve repair.
This patent application is currently assigned to EVALVE, INC.. The applicant listed for this patent is Chris BENDER, Eric A. GOLDFARB, Ted KETAI, Troy L. THORNTON, Steven A. TYLER. Invention is credited to Chris BENDER, Eric A. GOLDFARB, Ted KETAI, Troy L. THORNTON, Steven A. TYLER.
Application Number | 20130282059 13/852459 |
Document ID | / |
Family ID | 36477759 |
Filed Date | 2013-10-24 |
United States Patent
Application |
20130282059 |
Kind Code |
A1 |
KETAI; Ted ; et al. |
October 24, 2013 |
METHODS, SYSTEMS AND DEVICES FOR CARDIAC VALVE REPAIR
Abstract
Disclosed are methods, systems, and devices for the endovascular
repair of cardiac valves, particularly the atrioventricular valves
which inhibit back flow of blood from a heart ventricle during
contraction. The procedures described herein can be performed with
interventional tools, guides and supporting catheters and other
equipment introduced to the heart chambers from the patient's
arterial or venous vasculature remote from the heart. The
interventional tools and other equipment may be introduced
percutaneously or may be introduced via a surgical cut down, and
then advanced from the remote access site through the vasculature
until they reach the heart.
Inventors: |
KETAI; Ted; (San Francisco,
CA) ; BENDER; Chris; (Oakland, CA) ; TYLER;
Steven A.; (Portola Valley, CA) ; THORNTON; Troy
L.; (San Francisco, CA) ; GOLDFARB; Eric A.;
(Belmont, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KETAI; Ted
BENDER; Chris
TYLER; Steven A.
THORNTON; Troy L.
GOLDFARB; Eric A. |
San Francisco
Oakland
Portola Valley
San Francisco
Belmont |
CA
CA
CA
CA
CA |
US
US
US
US
US |
|
|
Assignee: |
EVALVE, INC.
Menlo Park,California
CA
|
Family ID: |
36477759 |
Appl. No.: |
13/852459 |
Filed: |
March 28, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12883095 |
Sep 15, 2010 |
|
|
|
13852459 |
|
|
|
|
61243459 |
Sep 17, 2009 |
|
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Current U.S.
Class: |
606/232 |
Current CPC
Class: |
A61B 17/0487 20130101;
A61B 2017/0409 20130101; A61F 2/2478 20130101; A61B 17/0401
20130101; A61B 2017/0496 20130101; A61F 2/2445 20130101; A61B
2017/0445 20130101; A61B 2017/0454 20130101; A61F 2/2412 20130101;
A61B 2017/0414 20130101; A61B 2017/0417 20130101; A61F 2210/009
20130101; A61B 2017/0435 20130101; A61B 2017/0427 20130101; A61B
2017/0464 20130101; A61B 17/29 20130101; A61B 2017/00783 20130101;
A61B 2017/0412 20130101; A61F 2/246 20130101; A61B 17/00234
20130101; A61F 2/2463 20130101; A61F 2/2487 20130101; A61F 2/2454
20130101; A61F 2220/0016 20130101; A61B 2017/00876 20130101; A61F
2/2457 20130101; A61B 2017/00243 20130101 |
Class at
Publication: |
606/232 |
International
Class: |
A61B 17/04 20060101
A61B017/04 |
Claims
1. A chordal replacement device comprising: a proximal anchor
comprising a flexible patch and a leaflet attachment device,
wherein the flexible patch is affixed to an upper surface of a
portion of a flailing leaflet with the leaflet attachment device; a
distal anchor extending and affixed to a distal attachment site in
a ventricle; and a flexible tether coupled to and tensioned between
the proximal and distal anchors.
2. The device of claim 1, wherein the leaflet attachment device
comprises a pair of expandable elements interconnected by a central
attachment rod.
3. The device of claim 2, wherein the pair of expandable elements
sandwich the flexible patch and the leaflet.
4. The device of claim 1, wherein the leaflet attachment device
comprises an expandable element.
5. The device of claim 1, wherein the expandable element is
self-deploying.
6. The device of claim 5, wherein the expandable element comprises
a star-shaped barb, a mesh web, or a mesh ball.
7. The device of claim 1, wherein the proximal anchor further
comprises a mesh stent deployable within an atrium.
8. The device of claim 7, wherein the mesh stent is coupled to a
flexible rod that extends through a valve commissure into the
ventricle.
9. The device of claim 8, wherein a distal end of the flexible rod
couples to the distal anchor and provides consistent tension on the
tether during a heart cycle.
10. The device of claim 8, wherein the flexible rod has a
deflectable, spring-formed shape.
11. The device of claim 8, wherein the flexible rod is jointed.
12. The device of claim 1, wherein the distal anchor and tensioned
flexible tether apply a downward force on the flailing leaflet.
13. The device of claim 1, wherein the distal anchor comprises a
weight, barb, adhesive, screw, or fluid-filled element.
14. The device of claim 1, wherein the distal attachment site
comprises a portion of the ventricle wall, ventricular septum or
papillary muscle.
15. The device of claim 14, wherein the distal anchor fine-tunes
the tension of the tether after the distal anchor is affixed to the
distal attachment site.
16. The device of claim 15, wherein the distal anchor comprises a
coil screw and wherein rotation of the coil screw fine-tunes the
tension on the tether.
17. The device of claim 15, wherein the distal anchor comprises a
balloon and wherein infusion of fluid into the balloon increases
tension on the tether.
18. The device of claim 1, wherein the flexible tether has a length
that can be adjusted to a desired tension to apply a downward force
on the flailing leaflet.
19. The device of claim 1, wherein the flexible tether comprises
one or more loops of a flexible material.
20. The device of claim 19, wherein the one or more loops are drawn
together at a distal end region with an enclosed element.
21. The device of claim 20, wherein the enclosed element couples
the one or more loops to the distal anchor.
22. The device of claim 21, wherein the one or more loops are
coupled to the proximal and distal anchors such that the one or
more loops self-equalize and evenly distribute tension on the
flailing leaflets and on distal attachment site.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a divisional of U.S. patent
application Ser. No. 12/883,095 filed Sep. 15, 2010, which claims
the benefit of priority under 35 U.S.C. .sctn.119(e) of U.S.
Provisional Patent Application Ser. No. 61/243,459, filed Sep. 17,
2009. This application is also a continuation-in-part of co-pending
U.S. patent application Ser. No. 11/349,742, filed on Feb. 7, 2006,
which claims the benefit of priority under 35 U.S.C. .sctn.119(e)
of U.S. Provisional Patent Application Ser. No. 60/650,918 entitled
"Methods, Systems and Devices for Cardiac Valve Repair," filed Feb.
7, 2005, and U.S. Provisional Patent Application Ser. No.
60/692,802 entitled "Methods, Systems and Devices for Cardiac Valve
Repair," filed Jun. 21, 2005. Priority of the aforementioned filing
dates is hereby claimed, and the full disclosures of the
aforementioned applications are hereby incorporated by reference in
their entirety.
BACKGROUND
[0002] The present invention relates generally to medical methods,
devices, and systems. In particular, the present invention relates
to methods, devices, and systems for the endovascular or minimally
invasive surgical repair of the atrioventricular valves of the
heart, particularly the mitral valve.
[0003] Mitral valve regurgitation is characterized by retrograde
flow from the left ventricle of a heart through an incompetent
mitral valve into the left atrium. During a normal cycle of heart
contraction (systole), the mitral valve acts as a check valve to
prevent flow of oxygenated blood back into the left atrium. In this
way, the oxygenated blood is pumped into the aorta through the
aortic valve. Regurgitation of the valve can significantly decrease
the pumping efficiency of the heart, placing the patient at risk of
severe, progressive heart failure.
[0004] Mitral valve regurgitation can result from a number of
different mechanical defects in the mitral valve. The valve
leaflets, the valve chordae which connect the leaflets to the
papillary muscles, or the papillary muscles themselves may be
damaged or otherwise dysfunctional. Commonly, the valve annulus may
be damaged, dilated, or weakened limiting the ability of the mitral
valve to close adequately against the high pressures of the left
ventricle. In some cases the mitral valve leaflets detach from the
chordae tendinae, the structure that tethers them to the
ventricular wall so that they are positioned to coapt or close
against the other valve leaflet during systole. In this case, the
leaflet "flails" or billows into the left atrium during systole
instead of coapting or sealing against the neighboring leaflet
allowing blood from the ventricle to surge into the left atrium
during systole. In addition, mitral valve disease can include
functional mitral valve disease which is usually characterized by
the failure of the mitral valve leaflets to coapt due to an
enlarged ventricle, or other impediment to the leaflets rising up
far enough toward each other to close the gap or seal against each
other during systole.
[0005] The most common treatments for mitral valve regurgitation
rely on valve replacement or strengthening of the valve annulus by
implanting a mechanical support ring or other structure. The latter
is generally referred to as valve annuloplasty. A recent technique
for mitral valve repair which relies on suturing adjacent segments
of the opposed valve leaflets together is referred to as the
"bow-tie" or "edge-to-edge" technique. While all these techniques
can be very effective, they usually rely on open heart surgery
where the patient's chest is opened, typically via a sternotomy,
and the patient placed on cardiopulmonary bypass. The need to both
open the chest and place the patient on bypass is traumatic and has
associated morbidity.
SUMMARY
[0006] For the foregoing reasons, it would be desirable to provide
alternative and additional methods, devices, and systems for
performing the repair of mitral and other cardiac valves, including
the tricuspid valve, which is the other atrioventricular valve. In
some embodiments of the present invention, methods and devices may
be deployed directly into the heart chambers via a trans-thoracic
approach, utilizing a small incision in the chest wall, or the
placement of a cannula or a port. In other embodiments, such
methods, devices, and systems may not require open chest access and
be capable of being performed endovascularly, i.e., using devices
which are advanced to the heart from a point in the patient's
vasculature remote from the heart. Still more preferably, the
methods, devices, and systems should not require that the heart be
bypassed, although the methods, devices, and systems should be
useful with patients who are bypassed and/or whose heart may be
temporarily stopped by drugs or other techniques. At least some of
these objectives will be met by the inventions described
hereinbelow.
[0007] In an aspect, disclosed herein is a chordal replacement
device having a proximal anchor including a flexible patch and a
leaflet attachment device. The flexible patch is affixed to an
upper surface of a portion of a flailing leaflet with the leaflet
attachment device. The device also includes a distal anchor
extending and affixed to a distal attachment site in a ventricle;
and a flexible tether coupled to and tensioned between the proximal
and distal anchors.
[0008] In another aspect, there is a chordal replacement device
having a proximal anchor including a flexible crimp clip having one
or more barbs that embed into and affix to a portion of a flailing
leaflet; a distal anchor extending and affixed to a distal
attachment site in a ventricle; and a flexible tether coupled to
and tensioned between the proximal and distal anchors.
[0009] The device can include a leaflet attachment device having a
pair of expandable elements interconnected by a central attachment
rod. The pair of expandable elements can sandwich the flexible
patch and the leaflet. The leaflet attachment device can include an
expandable element. The expandable element can be self-deploying
and can include a star-shaped barb, a mesh web, or a mesh ball. The
proximal anchor can further include a mesh stent deployable within
an atrium. The mesh stent can be coupled to a flexible rod that
extends through a valve commissure into the ventricle. The distal
end of the flexible rod can couple to the distal anchor and provide
consistent tension on the tether during a heart cycle. The flexible
rod can have a deflectable, spring-formed shape. The flexible rod
can be jointed. The distal anchor and tensioned flexible tether can
apply a downward force on the flailing leaflet. The distal anchor
can include a weight, barb, adhesive, screw, or fluid-filled
element. The distal attachment site can include a portion of the
ventricle wall, ventricular septum or papillary muscle. The distal
anchor can fine-tune the tension of the tether after the distal
anchor is affixed to the distal attachment site. The distal anchor
can include a coil screw and wherein rotation of the coil screw
fine-tunes the tension on the tether. The distal anchor can include
a balloon and wherein infusion of fluid into the balloon increases
tension on the tether.
[0010] The flexible tether can have a length that can be adjusted
to a desired tension to apply a downward force on the flailing
leaflet. The flexible tether can include one or more loops of a
flexible material. The one or more loops can be drawn together at a
distal end region with an enclosed element. The enclosed element
can couple the one or more loops to the distal anchor. The one or
more loops can be coupled to the proximal and distal anchors such
that the one or more loops self-equalize and evenly distribute
tension on the flailing leaflets and on distal attachment site.
[0011] In another aspect, disclosed is a chordal replacement device
including a proximal anchor comprising a flexible crimp clip having
one or more barbs that embed into and affix to a portion of a
flailing leaflet; a distal anchor extending and affixed to a distal
attachment site in a ventricle; and a flexible tether coupled to
and tensioned between the proximal and distal anchors.
[0012] The distal anchor and flexible tether can hold down the
flailing leaflet. The distal anchor can include a weight, barb,
adhesive, screw, or fluid-filled element. The distal attachment
site can include a portion of the ventricle wall, ventricular
septum or papillary muscle. The distal anchor can fine-tune the
tension of the tether after the distal anchor is affixed to the
distal attachment site. The distal anchor can include a coil screw
and wherein rotation of the coil screw fine-tunes the tension on
the tether. The distal anchor can include a balloon and wherein
infusion of fluid into the balloon increases tension on the tether.
The tether can have a length that can be adjusted to a desired
tension to hold the leaflet down.
[0013] In another aspect, disclosed is a method for repairing a
cardiac valve including accessing a patient's vasculature remote
from the heart; advancing an interventional tool through an access
sheath to a location near the cardiac valve, the interventional
tool comprising a distal flange; affixing a chordal replacement
device to a portion of a flailing leaflet, the chordal replacement
device including a flexible patch; one or more leaflet attachment
devices; a distal anchor; and a flexible tether coupled to and
tensioned between the flexible patch and the distal anchor. The
method also includes coupling the distal anchor to a distal
attachment site in a ventricle; and applying a downward force on
the flailing leaflet with the tether and distal anchor so as to
prevent flail of the leaflet into the atrium.
[0014] Affixing a chordal replacement device can further include
positioning the flexible patch on an upper surface of a flailing
leaflet, piercing the patch and the leaflet with the one or more
leaflet attachment devices, and sandwiching the leaflet and the
patch between a pair of expandable elements. The pair of expandable
elements can be self-deploying. The distal anchor can include a
weight, barb, adhesive, coil screw or fluid-filled element. The
distal attachment site can include a portion of the ventricle wall,
ventricular septum or papillary muscle. The method can further
include observing flow through the cardiac valve to determine if
leaflet flail, valve prolapse or valve regurgitation are inhibited.
The method can further include adjusting tension of the tether
coupled to and tensioned between the flexible patch and the distal
anchor. The distal anchor can include a coil screw and wherein
adjusting the tension of the tether comprises rotating the coil
screw. The distal anchor can include a balloon and wherein
adjusting the tension of the tether comprises infusing fluid into
the balloon. The method can further include sensing contact between
the distal anchor and the distal attachment site.
[0015] Other features and advantages should be apparent from the
following description of various embodiments, which illustrate, by
way of example, the principles of the disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1A is a schematic illustration of the left ventricle of
a heart showing blood flow during systole with arrows.
[0017] FIG. 1B shows a cross-sectional view of the heart wherein a
flexible stent is positioned at or near the mitral valve.
[0018] FIG. 2A shows a cross-sectional view of the heart showing
one or more magnets positioned around the annulus of the mitral
valve.
[0019] FIG. 2B shows an annular band with magnets that can be
positioned on the mitral valve annulus.
[0020] FIG. 3 shows a cross-sectional view of the heart identifying
locations for placement of valves.
[0021] FIG. 4 show a cross-sectional view of the heart with a pair
of flaps mounted at or near the mitral valve.
[0022] FIG. 5A shows a schematic side view of the mitral valve
leaflets with a flap positioned immediately below each leaflet.
[0023] FIG. 5B shows a downward view of the mitral valve with a
pair of exemplary flaps superimposed over the leaflets.
[0024] FIG. 5C shows a pair of mitral valve leaflet flaps having
complementary shapes.
[0025] FIG. 6A shows a cross-sectional view of the heart with a
membrane ring positioned at the mitral valve annulus.
[0026] FIG. 6B shows a schematic view of the membrane ring, which
includes an annular ring on which is mounted a membrane.
[0027] FIG. 7A shows a cross-sectional view of a heart with a
bladder device positioned partially within the left ventricle and
partially within the left atrium.
[0028] FIG. 7B shows a schematic side view of the mitral valve
leaflets failing to coapt.
[0029] FIG. 7C shows a schematic side view of the mitral valve
leaflets with a bladder positioned between the leaflets.
[0030] FIG. 7D shows a plan view of the mitral valve with the
leaflets in an abnormal closure state such that a gap is present
between the leaflets.
[0031] FIG. 8 shows a cross-sectional view of the heart wherein a
one-way valve device is located in the left atrium.
[0032] FIG. 9A shows a prosthetic ring that is sized to fit within
a mitral valve.
[0033] FIG. 9B shows another embodiment of a prosthetic ring
wherein a one-way valve is positioned inside the ring.
[0034] FIG. 10 shows a prosthetic with one or more tongues or flaps
that are configured to be positioned adjacent the flaps of the
mitral valve.
[0035] FIG. 11A shows an exemplary embodiment of one or more clips
that are positioned on free edges of the leaflets.
[0036] FIG. 11B shows pair of leaflets with a magnetic clip
attached to the underside of each leaflet.
[0037] FIG. 11C shows the leaflets coapted as a result of the
magnetic attraction between the magnetic clips.
[0038] FIG. 11D shows a pair of leaflets with a single clip
attached to one of the leaflets.
[0039] FIG. 12 shows a schematic, cross-sectional view of the heart
with a wedge positioned below at least one of the leaflets of the
mitral valve.
[0040] FIG. 13A shows an artificial chordae tendon.
[0041] FIGS. 13B and 13C show attachment devices for attaching the
artificial chordae tendon to a heart wall.
[0042] FIG. 14 shows a cross-sectional view of the heart with a
first and second anchor attached to a wall of the heart.
[0043] FIG. 15 shows a catheter that has been introduced into the
heart.
[0044] FIG. 16 shows a schematic view of a papillary muscle with a
ring positioned over the muscle.
[0045] FIG. 17 shows a cross-sectional view of the heart with one
or more magnets attached to a wall of the left ventricle.
[0046] FIG. 18A shows another embodiment of a procedure wherein
magnets are implanted in the heart to geometrically reshape the
annulus or the left ventricle.
[0047] FIG. 18B shows the heart wherein tethered magnets are
implanted in various locations to geometrically reshape the annulus
or the left ventricle.
[0048] FIG. 18C shows the heart wherein magnets are implanted in
various locations to geometrically reshape the annulus or the left
ventricle.
[0049] FIG. 19 shows another embodiment of a procedure wherein
magnets are implanted in the heart to geometrically reshape the
annulus or the left ventricle.
[0050] FIG. 20 shows a cross-sectional view of the left ventricle
with a tether positioned therein.
[0051] FIG. 21 shows a cross-sectional view of the left ventricle
with a delivery catheter positioned therein.
[0052] FIG. 22 shows a cross-sectional view of the left ventricle
with the delivery catheter penetrating a wall of the left
ventricle.
[0053] FIG. 23 shows a cross-sectional view of the left ventricle
with the delivery catheter delivering a patch to the wall of the
left ventricle.
[0054] FIG. 24 shows a cross-sectional view of the left ventricle
with the delivery penetrating delivering a second patch.
[0055] FIG. 25 shows a cross-sectional view of the left ventricle
with two tethers attached together at opposite ends from the
patches mounted in the heart.
[0056] FIG. 26 shows a cross-sectional view of the left ventricle
with a needle or delivery catheter passed transthoracically into
the left ventricle LV to deliver a patch to the exterior of the
ventricular wall.
[0057] FIG. 27 shows a schematic, cross-sectional view of the left
ventricle in a healthy state with the mitral valve closed.
[0058] FIG. 28 shows the left ventricle in a dysfunctional
state.
[0059] FIG. 29 shows the left ventricle with a biasing member
mounted between the papillary muscles.
[0060] FIG. 30 shows the left ventricle with a suture mounted
between the papillary muscles.
[0061] FIG. 31 shows the left ventricle with a snare positioned
around the chordae at or near the location where the chordae attach
with the papillary muscles.
[0062] FIG. 32 shows a leaflet grasping device that is configured
to grasp and secure the leaflets of the mitral valve.
[0063] FIGS. 33A-33C show the leaflet grasping device grasping
leaflets of the mitral valve.
[0064] FIG. 34 shows the left ventricle with a needle being
advanced from the left atrium into the left ventricle via the
leaflet grasping device.
[0065] FIG. 35 shows the left ventricle with sutures holding the
papillary muscles in a desired position.
[0066] FIG. 36 shows a cross-sectional view of the heart with one
or more clips clipped to each of the papillary muscles.
[0067] FIG. 37 shows a cross-sectional view of the heart with
tethered clips attached to opposed walls of the left ventricle.
[0068] FIGS. 38A-38C show an embodiment of a chordal replacement
device.
[0069] FIGS. 39A-39M show another embodiment of a chordal
replacement device.
[0070] FIGS. 39N-39O show an embodiment of a dual function clamp
and deployment of an embodiment of a chordal replacement
device.
[0071] FIGS. 40A-40B show another embodiment of a chordal
replacement device.
[0072] FIGS. 41A-41B show a cross-sectional view of the chordal
replacement device of FIGS. 40A-40B being deployed.
[0073] FIGS. 41C-41E show an embodiment of an attachment device
fixing a chordal replacement device to a valve leaflet.
[0074] FIG. 41F shows an embodiment of an expandable feature of an
attachment device having a star-shaped design.
[0075] FIGS. 41G-41P show embodiments of a leaflet stabilizing
mechanism.
[0076] FIGS. 42A-42D show various embodiments of an expandable
feature of an attachment device.
[0077] FIGS. 43A-43B show an embodiment of attachment devices
fixing a patch to a valve leaflet.
[0078] FIGS. 44A-44D show various steps in the deployment of an
embodiment of a chordal replacement device.
[0079] FIGS. 45A-45D show various embodiments of a distal
attachment assembly deployed in the ventricle wall.
[0080] FIGS. 46A-46B show an embodiment of a sensor used in the
adjustment of artificial chordae tension.
[0081] FIG. 47 illustrates an embodiment of fine-tuning the tension
on the artificial chordae.
[0082] FIGS. 48A-48B illustrate another embodiment of fine-tuning
the tension on the artificial chordae.
[0083] FIGS. 49A-49B show another embodiment of an attachment
assembly for a chordal replacement device.
[0084] FIGS. 50A-50B show another embodiment of an attachment
assembly for a chordal replacement device.
[0085] FIGS. 50C-50E show an embodiment of a jointed rod having
mechanical locking feature.
[0086] FIG. 50F illustrates the independent pivot axes of a jointed
rod system.
[0087] FIGS. 51A-51B show another embodiment of an attachment
assembly for a chordal replacement device.
[0088] FIGS. 52A-52C show an embodiment of a leaflet extension
device blocking valve leaflet flail.
DETAILED DESCRIPTION
[0089] The present invention provides methods, systems, and devices
for the endovascular repair of cardiac valves, particularly the
atrioventricular valves which inhibit back flow of blood from a
heart ventricle during contraction (systole), most particularly the
mitral valve between the left atrium and the left ventricle. By
"endovascular," it is meant that the procedure(s) of the present
invention are performed with interventional tools, guides and
supporting catheters and other equipment introduced to the heart
chambers from the patient's arterial or venous vasculature remote
from the heart. The interventional tools and other equipment may be
introduced percutaneously, i.e., through an access sheath, or may
be introduced via a surgical cut down, and then advanced from the
remote access site through the vasculature until they reach the
heart. Thus, the procedures of the present invention will generally
not require penetrations made directly through the exterior heart
muscle, i.e., myocardium, although there may be some instances
where penetrations will be made interior to the heart, e.g.,
through the interatrial septum to provide for a desired access
route.
[0090] While the procedures of the present invention will usually
be percutaneous and intravascular, many of the tools will find use
in minimally invasive and open surgical procedures as well that
includes a surgical incision or port access through the heart wall.
In particular, the tools for capturing the valve leaflets prior to
attachment can find use in virtually any type of procedure for
modifying cardiac valve function.
[0091] The atrioventricular valves are located at the junctions of
the atria and their respective ventricles. The atrioventricular
valve between the right atrium and the right ventricle has three
valve leaflets (cusps) and is referred to as the tricuspid or right
atrioventricular valve. The atrioventricular valve between the left
atrium and the left ventricle is a bicuspid valve having only two
leaflets (cusps) and is generally referred to as the mitral valve.
In both cases, the valve leaflets are connected to the base of the
atrial chamber in a region referred to as the valve annulus, and
the valve leaflets extend generally downwardly from the annulus
into the associated ventricle. In this way, the valve leaflets open
during diastole when the heart atria fill with blood, allowing the
blood to pass into the ventricle.
[0092] During systole, however, the valve leaflets are pushed
together and closed to prevent back flow of blood into the atria.
The lower ends of the valve leaflets are connected through
tendon-like tissue structures called the chordae, which in turn are
connected at their lower ends to the papillary muscles.
Interventions according to the present invention may be directed at
any one of the leaflets, chordae, annulus, or papillary muscles, or
combinations thereof. It will be the general purpose of such
interventions to modify the manner in which the valve leaflets
coapt or close during systole so that back flow or regurgitation is
minimized or prevented.
[0093] The left ventricle LV of a normal heart H in systole is
illustrated in FIG. 1A. The left ventricle LV is contracting and
blood flows outwardly through the tricuspid (aortic) valve AV in
the direction of the arrows. Back flow of blood or "regurgitation"
through the mitral valve MV is prevented since the mitral valve is
configured as a "check valve" which prevents back flow when
pressure in the left ventricle is higher than that in the left
atrium LA. The mitral valve MV comprises a pair of leaflets having
free edges FE which meet evenly to close, as illustrated in FIG.
1A. The opposite ends of the leaflets LF are attached to the
surrounding heart structure along an annular region referred to as
the annulus AN. The free edges FE of the leaflets LF are secured to
the lower portions of the left ventricle LV through chordae
tendineae CT (referred to hereinafter as the chordae) which include
plurality of branching tendons secured over the lower surfaces of
each of the valve leaflets LF. The chordae CT in turn, are attached
to the papillary muscles PM which extend upwardly from the lower
portions of the left ventricle and interventricular septum IVS.
[0094] While the procedures of the present invention will be most
useful with the atrioventricular valves, at least some of the tools
described hereinafter may be useful in the repair of other cardiac
valves, such as peripheral valves or valves on the venous side of
the cardiac circulation, or the aortic valve.
[0095] The methods of the present invention can comprise accessing
a patient's vasculature at a location remote from the heart,
advancing an interventional tool through the vasculature to a
ventricle and/or atrium, and engaging the tool against a tissue
structure which forms or supports the atrioventricular valve. By
engaging the tool against the tissue structure, the tissue
structure is modified in a manner that reduces valve leakage or
regurgitation during ventricular systole. The tissue structure may
be any of one or more of the group consisting of the valve
leaflets, chordae, the valve annulus, and the papillary muscles,
atrial wall, ventricular wall or adjacent structures. Optionally,
the interventional tool will be oriented relative to the
atrioventricular valve and/or tissue structure prior to engaging
the tool against the tissue structure. The interventional tool may
be self-orienting (e.g., pre-shaped) or may include active
mechanisms to steer, adjust, or otherwise position the tool.
[0096] Alternatively, orientation of the interventional tool may be
accomplished in whole or in part using a separate guide catheter,
where the guide catheter may be pre-shaped and/or include active
steering or other positioning means such as those devices set forth
in United States Patent Publication Numbers 2004/0044350,
2004/0092962, and 2004/0087975, all of which are expressly
incorporated by reference herein. In all cases, it will usually be
desirable to confirm the position prior to engaging the valve
leaflets or other tissue structures. Such orienting step may
comprise positioning the tool relative to a line of coaptation in
the atrioventricular valve, e.g., engaging positioning elements in
the valve commissures and confirming the desired location using a
variety of imaging means such as magnetic resonant imaging (MRI),
intracardiac echocardiography (ICE), transesophageal echo (TEE),
fluoroscopy, endoscopy, intravascular ultrasound (IVUS) and the
like.
[0097] In some embodiments, heart disease in general, and valve
repair in particular, are treated by targeting the pacing of the
heartbeat. In one embodiment, heart disease is treated by
introducing one or more pacing leads into a heart chamber. The
pacing leads are placed in contact with a heart muscle and are in
electrical communication with a power source. The power source
provides paced electrical stimuli to the heart muscle. The
electrical stimuli are provided during or immediately after systole
to extend systolic contraction of the heart, thereby extending the
range of systole during each heartbeat. This extension of systole
extends the amount of time in which the heart muscle tightens when
it would otherwise be relaxing, when there is most mitral
regurgitation in diseased mitral valves.
[0098] Other embodiments are directed to annuloplasty to treat
heart disease in general and valve repair in particular. In one
embodiment, shown generally in FIG. 1B, a stent is used to treat
the mitral valve. FIG. 1B shows a cross-sectional view of the heart
wherein a flexible stent 100 is positioned at or near the mitral
valve MV. The stent 100 is annular and is sized and shaped to be
positioned on the annulus of the mitral valve. The stent 100 can
transition between a collapsed state of reduced size and an
expanded state of enlarged size relative to the collapsed
state.
[0099] The flexible stent 100 can be percutaneously introduced into
an individual's heart while being biased toward the collapsed
state. The stent is advanced partially through the annulus of the
mitral valve so that it is coaxially positioned within the annulus,
as shown in FIG. 1B. The stent 100 is then secured to the annulus
such that the stent exerts an inward force on the annulus thereby
causing the annulus to resist dilation during diastole of the
heart.
[0100] In yet another embodiment, a device is disclosed for
treating the mitral valve. The device can be a stent, such as the
stent 100, that is sized to fit coaxially within an annulus of a
mitral valve. The stent includes a hollow frame. The frame can be
annular such that it has a cross-sectional diameter that is sized
such that an outer surface of the frame is in continuous coaxial
contact with the annulus. The frame also includes one or more
anchors protruding from it for securing the stent to the annulus.
The anchors can be prongs, barbs, protrusions, or any structure
adapted to secure the stent to the annulus. The stent is flexible
between an expanded configuration and a contracted configuration
and is biased toward the contracted configuration so that it exerts
an inward force on the annulus.
[0101] In one embodiment, the stent 100 is delivered using a
delivery catheter 10 that is advanced from the inferior vena cava
IVC into the right atrium RA. Once the catheter 10 reaches the
anterior side of the interatrial septum IAS, a needle 12 may be
advanced so that it penetrates through the septum at the fossa
ovalis FO or the foramen ovale into the left atrium LA. At this
point, a delivery device can be exchanged for the needle and the
delivery device used to deliver the stent 100. The catheter 10 can
also approach the heart in other manners.
[0102] FIG. 2A shows a cross-sectional view of the heart showing
one or more magnets 205 positioned around the annulus of the mitral
valve MV. A corresponding method of treating heart disease involves
the use of magnets. The method includes percutaneously introducing
at least a first magnet 205 into an individual's heart and securing
it to the mitral valve MV annulus. At least a second magnet 205 is
percutaneously introduced into the heart and advanced so that it is
within a magnetic field of the first magnet. The second magnet is
secured to the heart. The polarity of one of the two magnets is
then cyclically changed in synchronization with the heart beat so
that the magnets attract and repel each other in synchronization
with the heart beat. The first magnet therefore moves in relation
to the second magnet and exerts an inward closing force on the
mitral valve during systole. The magnets 205 can be positioned on
an annular band 215 (shown in FIG. 2B) that is sized and shaped to
be implanted on the annulus of the mitral valve. The band 215 can
be, for example, a stent.
[0103] In one embodiment, the magnets 205 or the annular band 215
are delivered using a delivery catheter 10 that is advanced from
the inferior vena cava IVC into the right atrium RA, as described
above with reference to FIG. 1. Any of the devices described herein
can be percutaneously delivered into the heart by coupling the
device to a delivery device, such as a steerable delivery
catheter.
[0104] In yet another embodiment involving magnets, two or more
magnets are percutaneously introduced into an individual's coronary
sinus such that they attract or repel each other to reshape the
coronary sinus and an underlying mitral valve annulus.
[0105] Other embodiments involve various prosthetics for treating
heart disease in general and defective or diseased mitral valves in
particular. In one embodiment, a method of treatment includes
placing one or more one-way valves in one or more pulmonary veins
of an individual either near the ostium of the vein or at some
point along the length of the PV. Valves that may be used, for
example may be stentless valves such as designs similar to the
TORONTO SPV.RTM. (Stentless Porcine Valve) valve, mechanical or
tissue heart valves or percutaneous heart valves as are known in
the art provided they are sized appropriately to fit within the
lumen of the pulmonary vein, as shown in FIG. 3. In FIG. 3, the
locations in the left atrium LA where valves can be positioned in
pulmonary vein orifices are represented by an "X". In addition,
certain venous valve devices and techniques may be employed such as
those described in U.S. Pat. Nos. 6,299,637 and 6,585,761, and
United States Patent Publication Numbers 2004/0215339 and
2005/0273160, the entire contents of which are incorporated herein
by reference. A valve prosthesis for placement in the ostia of the
pulmonary vein from the left atrium may be in the range of 6-20 mm
in diameter. Placement of individual valves in the pulmonary vein
ostia (where the pulmonary veins open or take off from the left
atrium) may be achieved by obtaining trans septal access to the
left atrium with a steerable catheter, positioning a guidewire
through the catheter and into the targeted pulmonary vein, and
deploying a valve delivery catheter over the guidewire and
deploying the valve out of the delivery catheter. The valve may be
formed of a deformable material, such as stainless steel, or of a
self-expanding material such as NiTi, and include tissue leaflets
or leaflets formed of a synthetic material, such as is known in the
art. A line of +++++ symbols in FIG. 3 represents a mid-atrial
location above the mitral valve where a single valve can be
positioned as disclosed later in this specification.
[0106] The following references, all of which are expressly
incorporated by reference herein, describe devices (such as
steerable catheters) and methods for delivering interventional
devices to a target location within a body: United States Patent
Publication Numbers 2004/0044350, 2004/0092962 and
2004/0087975.
[0107] FIG. 4 show a cross-sectional view of the heart with a pair
of flaps mounted at or near the mitral valve. FIG. 5A shows a
schematic side view of the mitral valve leaflets LF with a flap 300
positioned immediately below each leaflet. The flap 300 can be
contoured so as to conform at least approximately to the shape of a
leaflet, or the flap 300 can be straight as shown in FIG. 4. FIG.
5B shows a downward view of the mitral valve with a pair of
exemplary flaps superimposed over the leaflets LF. As shown in FIG.
5C, the flaps can have complementary shapes with a first flap
having a protrusion that mates with a corresponding recess in a
second flap.
[0108] In corresponding method of treatment, shown in FIGS. 4 and
5C, a first flap 300 with an attachment end 305 and a free end 310
is provided. The attachment end 305 of the first flap 300 is
secured to the inside wall of the ventricle below the mitral valve.
A second flap 315 with an attachment end 320 and a free end 330 is
provided and is also secured to the inside wall of the ventricle
below the mitral valve. The first and second flaps 300, 315 are
oriented so that they face each other and the free ends 310, 330
are biased toward each other and approximate against each other
during systole. This system provides a redundant valving system to
assist the function of the native mitral valve.
[0109] In other embodiments, devices and methods that involve
prosthetic discs are disclosed. For example, FIG. 6A shows a
cross-sectional view of the heart with a membrane ring 610
positioned at the mitral valve annulus. FIG. 6B shows a schematic
view of the membrane ring 610, which includes an annular ring on
which is mounted a membrane. The membrane includes a series of
perforations 615 extending through the membrane surface. One or
more anchor devices, such as prongs, can be located on the ring for
securing the ring to the mitral valve.
[0110] In one embodiment, a device for treating heart disease in
general and defective or diseased mitral valves in particular
includes a disc having a ring, a membrane stretched across an
opening of the ring, and one or more anchors for securing the disc
to an annulus of a mitral valve. The disc is sized to cover the
annulus of the mitral valve, and the membrane includes one or more
perforations that permit one way fluid flow through the disc.
Methods of treatment using the device are also provided.
[0111] In other embodiments, devices and methods that involve
fluid-filled bladders are disclosed. FIG. 7A shows a
cross-sectional view of a heart with a bladder device positioned
partially within the left ventricle and partially within the left
atrium. A device for treating heart disease in general and
defective or diseased mitral valves in particular includes a
fluid-filled bladder 600. The bladder 600 is placed across the
mitral valve between the left atrium and the left ventricle. Upon
compression of the left ventricle, the volume of the bladder is
expanded on the left atrial side of the heart, providing a baffle
or sealing volume to which the leaflets of the mitral valve coapt.
The bladder may also act as a blocking device in the case of flail
of a leaflet, blocking said flailing leaflet from billowing into
the left atrium causing regurgitation. The bladder also includes
one or more anchors for securing the bladder to an annulus of a
mitral valve, or may be formed on a cage or other infrastructure to
position it within the line of coaptation of the mitral valve.
[0112] A bladder can also be used to treat functional mitral valve
disease. As mentioned, functional mitral valve disease is usually
characterized by the failure of the mitral valve leaflets to coapt
due to an enlarged ventricle, or other impediment to the leaflets
rising up far enough toward each other to close the gap or seal
against each other during systole. FIG. 7B shows a schematic side
view of the mitral valve leaflets LF failing to coapt such that
regurgitation can occur (as represented by the arrow RF.) With
reference to FIG. 7C, a baffle or bladder 630 is positioned between
the leaflets LF along the line of coaptation of the leaflets. The
bladder 630 provides a surface against which at least a portion of
the leaflets LF can seal against. The bladder 630 thus serves as a
coaptation device for the leaflets. The bladder can be attached to
various locations adjacent to or on the mitral valve. FIG. 7D shows
a plan view of the mitral valve with the leaflets LF in an abnormal
closure state such that a gap G is present between the leaflets. In
one embodiment, the bladder is attached or anchored to the mitral
valve at opposite edges E of the gap G.
[0113] Methods of treatment using the bladder include providing the
bladder and inserting it through an annulus of a mitral valve such
that the bladder is coaxially positioned through the mitral valve.
An atrial portion of the bladder extends into the left atrium, and
a ventricular portion of the bladder extends into the left
ventricle. A mid portion of the bladder may be secured to the
annulus of the mitral valve such that the mid portion remains
stationery while the atrial and ventricular portions expand and
contract passively between the atrium and ventricle based on
pressure differentials during systole and diastole.
[0114] FIG. 8 shows a cross-sectional view of the heart wherein a
one-way valve device 700 is located in the left atrium. The valve
device is represented schematically in FIG. 8. A corresponding
method of treating heart disease includes introducing a one-way
valve device 700 into the left atrium of an individual's heart
proximal the mitral valve. The valve device 700 is configured to
permit fluid flow in one direction while preventing fluid flow in
an opposite direction. The valve device can have various
structures. For example, the device can comprise a valve that is
mounted on a stent that is sized to be positioned in the left
atrium. Valves that may be used, for example may be stentless
valves such as the TORONTO SPV.RTM. (Stentless Porcine Valve)
valve, mechanical or tissue heart valves or percutaneous heart
valves as are known in the art. The outer wall of the one-way valve
device is sealed to the inner wall of the atrium so that a
fluid-tight seal is formed between the outer wall of the one-way
valve device and the inner wall of the left atrium. In this regard,
the valve device can include a seal member that is configured to
seal to the inner wall of the atrium.
[0115] Another embodiment involves a prosthetic for treating heart
disease in general and defective or diseased mitral valves in
particular. FIG. 9A shows a prosthetic ring 800 that is sized to
fit within a mitral valve annulus The ring includes one or more
anchors 805 that extend around the periphery of the ring 800. In
addition, one or more struts 810 struts extend across the diameter
of the ring, and can be made of a material that includes Nitinol or
magnetic wires for selectively adjusting the shape of the ring. The
struts can also be instrumental in baffling mitral valve leaflet
"flail". FIG. 9B shows another embodiment of a prosthetic ring 807
wherein a one-way valve 815 is positioned inside the ring such that
blood flow BF can flow through the valve in only one direction. The
valve can be manufactured of various materials, such as
silicone.
[0116] FIG. 10 shows a prosthetic with one or more tongues or flaps
that are configured to be positioned adjacent the flaps of the
mitral valve. The prosthetic includes a ring 900 sized to fit
within a mitral valve annulus. At least two tongues 910 project
from the ring 900 in a caudal direction when the ring is implanted
into a heart of an individual. The ring is flexible between an
expanded configuration and a contracted configuration and is biased
toward the contracted configuration. One or more anchors 920
protrude from the flexible ring for coupling the ring coaxially to
the annulus such that the contracted configuration of the ring
exerts an inward force to the annulus. Alternatively, or in
addition, the two tongues can each have a length sufficient to
prevent prolapse of a mitral valve when the ring is placed atop the
leaflets of the mitral valve. In a further embodiment the tongue
elements may be attached at a central point.
[0117] In yet another embodiment, a prosthetic for treating heart
disease in general and a defective or diseased mitral valve in
particular includes a wedge. The wedge has a length that is about
equal to a length of the line of coaptation of a mitral valve. The
wedge has a depth sufficient to prevent prolapse of a mitral valve
when the wedge is placed atop an annulus of the mitral valve along
the line of coaptation, and may provide a point of coaptation for
each leaflet. One or more anchors protrude from the wedge for
coupling the wedge to the annulus of the mitral valve. Methods of
treatment using the wedge are also disclosed. The methods include
inserting the wedge into an individual's heart, placing the wedge
lengthwise along the line of coaptation of the mitral valve. The
wedge is then secured to an annulus of the mitral valve along the
line of coaptation. The wedge may be positioned also just under one
segment of the leaflet (likely P2 in the case of functional
MR).
[0118] In yet another embodiment, a device for treating heart
disease includes a clip for attachment to a free end of a heart
valve leaflet. FIG. 11A shows an exemplary embodiment of one or
more clips 1101 that are positioned on free edges of the leaflets
LF. Each of the clips 1101 has a shape that prevents flail of the
leaflet by catching against an underside of an opposing leaflet.
Methods of treatment using the clip are also disclosed. The methods
include introducing the clip into an individual's heart and
attaching the clip to a free end of a heart valve leaflet opposite
the free end of an opposing leaflet of the heart valve so that the
clip catches to the underside of the opposing leaflet during
systole. In a further embodiment, a clip may be placed on both
leaflets such that the clips meet or catch when the leaflets are in
proximity. The clips may attach momentarily during systole, and
then detach during diastole, or may clip permanently resulting in a
double orifice mitral valve anatomy. The clips of this embodiment
may include a magnetic element, or one may be magnetic and the
other of a metal material attracted to said electromagnetic field
of the magnetic clip.
[0119] In the case of magnetic clips, the clip elements may be
placed on the underside of the leaflets (e.g. not necessarily on
the free edge of the leaflet), provided that the magnetic field of
the clip is sufficient to attract the opposing magnetic or metal
clip element. This is further described with reference to FIG. 11B,
which shows pair of leaflets LF with a clip 1101 attached to the
underside of each leaflet. At least one of the clips is magnetic,
while the other clip is of an opposite magnetic polarity than the
first clip or of a metal attracted to the magnetic field of the
first clip. The magnetic field is sufficiently strong such that the
clips 1101 can attach to one another either momentarily or
permanently to coapt the leaflets, as shown in FIG. 11C.
[0120] In another embodiment, shown in FIG. 11D, a single clip 1101
is attached to one of the leaflets. The clip 1101 is sufficiently
long to increase the likelihood that the clip 1101 will coapt with
the opposite leaflet.
[0121] In yet another embodiment, a device for treating heart
disease includes a wedge for placement under a heart valve leaflet.
FIG. 12 shows a schematic, cross-sectional view of the heart with a
wedge 1205 positioned below at least one of the leaflets of the
mitral valve. The wedge 1205 can be positioned below one or both of
the leaflets. The wedge 1205 is sized to fit under the valve
leaflet and caudal the annulus of the heart valve. The wedge 1205
can have a shape that is contoured so as to provide support to a
lower surface of the leaflet. (In FIG. 12, the left atrium is
labeled LA and the left ventricle is labeled LV.) An anchor is
attached to the wedge for coupling the wedge to a wall of the heart
chamber adjacent the heart valve. The wedge forms a fixed backstop
against the bottom side of the heart valve leaflet, thereby
providing a location for the leaflet to coapt against, and/or
providing support or "pushing up" a restricted leaflet.
[0122] Other embodiments are directed to altering the size, shape,
chemistry, stiffness, or other physical attributes of heart valve
leaflets. In one embodiment in particular, a method of treating
heart disease includes obtaining access to a heart valve leaflet
and injecting a stiffening agent into the leaflet to stiffen the
leaflet and minimize flail.
[0123] Other embodiments are directed to the chordae that connect
heart valve leaflets to the inner walls of the heart. In one
embodiment in particular, a method of treating heart disease
includes obtaining access to a heart valve chord and cutting it
mechanically or with energy such as a laser, or by heating the
chordae to elongate them, thereby allowing the previously
restricted leaflet to be less restricted so that it can coapt with
the opposing leaflet.
[0124] In another embodiment directed to the chordae that connect
heart valve leaflets to the inner walls of the heart, a cam-shaped
ring is disclosed. The cam-shaped ring is sized to fit within a
left ventricle of a heart. The ring forms a hole that is sized to
receive two or more chordae tendineae. The ring is formed by
connecting two detachable ends of the ring.
[0125] Methods of treatment using the cam-shaped ring are also
disclosed. One method in particular includes introducing the ring
into a left ventricle of a heart. One or more chordae tendineae are
then surrounded by the ring, and the two ends of the ring are then
attached to form a closed ring around the chordae tendineae. The
ring is then rotated such that one or more of the chordae tendineae
are shifted away from their initial orientation by the rotation of
the cam-shaped ring. The ring may then be fixed in the rotated or
tightened position.
[0126] An embodiment directed at the chordae of heart valve
leaflets is now described. FIG. 13A shows a device that can be used
to alter a chordae. A method includes obtaining access to a chordae
tendinea (chord) within an individual's heart chamber. The chordae
is then cut at a point along its length so that a length of the
chordae tendinea is freed from the heart chamber leaving behind a
length of chordae tendinea having a free end and an end attached to
an edge of a heart valve.
[0127] With reference to FIG. 13A, a synthetic chord 1005 of
greater length than the free length of chordae is introduced into
the heart chamber. One end of the synthetic chordae 1005 is
connected to a wall 1305 of the heart chamber or to a muscle
attached to the wall of the heart chamber. Another end of the
synthetic chord is attached to the free end of the chorda tendinea
or to the leaflet.
[0128] In this regard, the end of the chord 1005 that is attached
the wall 1305 can have any of a variety of devices that facilitate
such attachment. FIGS. 13B and 13C show enlarged views of
attachment devices contained within box 13 of FIG. 13A. The
attachment devices can be used to attach the chord 1005 to the wall
1305. In FIG. 13B, the attachment device 1310 is an enlarged ball
having a distal trocar for penetrating the wall 1305. In FIG. 13C,
the attachment device 1310 is a hook that is configured to
penetrate through the wall 1305. It should be appreciated that the
attachment device 1310 can have other structures and it not limited
to the structures shown in FIGS. 13B and 13C. In variations of
these embodiments, it may be advantageous to adjust the length of
the chordae (synthetic, or modified), determine the therapeutic
effect of the shortening or lengthening, and then fix the chordae
at the most efficacious location.
[0129] Valve regurgitation due to flail or broken chordae can
occur. Such valve impairments can be treated percutaneously through
chordal replacement or the supplementing of the chordae tendineae
of the mitral valve. Although the embodiments described herein are
with reference to treating mitral valve impairments it should be
appreciated that other valves could similarly be treated with the
embodiments described herein. The configuration of the chordal
replacement devices described herein can vary. Features of the
various devices and their anchoring systems can be used in
combination with any of the embodiments described herein.
[0130] The chordal replacement devices described herein can be
delivered using interventional tools, guides and supporting
catheters and other equipment introduced to the heart chambers from
the patient's arterial or venous vasculature remote from the heart.
The chordal replacement devices described herein can be compressed
to a low profile for minimally-invasive or percutaneous delivery.
They can be advanced from the remote access site through the
vasculature until they reach the heart. For example, the chordal
replacement devices can be advanced from a venous site such as the
femoral vein, jugular vein, or another portion of the patient's
vasculature. It is also appreciated that chordal replacement
devices can be inserted directly into the body through a chest
incision. A guidewire can be steered from a remote site through the
patient's vasculature into the inferior vena cava (IVC) through the
right atrium so that the guidewire pierces the interatrial septum.
The guidewire can then extend across the left atrium and then
downward through the mitral valve MV to the left ventricle. After
the guidewire is appropriately positioned, a catheter can be passed
over the guidewire and used for delivery of a chordal replacement
device.
[0131] Embodiments of the chordal replacement devices described
herein can also be delivered using a catheter advanced through
retrograde access through, for example an artery, across the aortic
arch and the aortic valve and to the mitral valve by way of the
ventricle. Alternative delivery methods of chordal replacement
device embodiments described herein can include inserting the
device through a small access port such as a mini-thoracotomy in
the chest wall and into the left ventricle apex. From there, the
chordal replacement device can be advanced through the left
ventricle into the left atrium. It should be appreciated the device
can also be delivered via the left atrial apex as well. Positioning
of the tool and/or chordal replacement devices described herein can
be confirmed using a variety of imaging means such as magnetic
resonant imaging (MRI), intracardiac echocardiography (ICE),
transesophageal echo (TEE), fluoroscopy, endoscopy, intravascular
ultrasound (IVUS) and the like.
[0132] In an embodiment and as shown in FIGS. 38A-38C, a chordal
replacement device 3805 can include a laterally-stabilized spring
or flexible rod. In one embodiment, the device 3805 can include a
first portion 3810 that receives and/or is movable with respect to
a second portion 3815. The first and second portions 3810, 3815 can
be surrounded by a spring 3820. Each of the first and second
portions 3810, 3815 of the device 3805 can have a platform region
3825, 3830, respectively between which the spring 3820 extends. The
platform regions 3825, 3830 can be of sufficient surface area or
diameter that they can push against the heart wall and the leaflet
surface without damaging or puncturing the surfaces. In an
embodiment, the platform regions 3825, 3830 can also each have one
or more barbs 3835 or another fixation device on an external
surface that can implant and attach the device 3805 between the
valve leaflet and the roof of the atrium (see FIG. 38C). It should
also be appreciated that other attachment mechanisms for attaching
one or more of the platform sections to the valve leaflet and/or
the roof of the atrium are possible and that the device is not
limited to including barbs. For example, one or more of the
platforms can include clips such as a clip similar to the
Mitraclip.RTM. to grasp the leaflet, and an adhesive or screw to
attach to the roof of the atrium.
[0133] The chordal replacement device 3805 can be delivered into
the left atrium through a guide catheter 3840 (see FIG. 38B). A
tether 3845 can hold the device 3805 normal to the tip of the guide
catheter 3840. The tether 3845 can be threaded through the guide
catheter 3840, through the implant 3805, and back out the guide
catheter 3840. When the procedure is completed, the tether 3845 can
be pulled out of the guide catheter 3840 from either end releasing
the implant, allowing deployment. Other mechanisms of attachment to
the implant 3805 are considered herein. For example, the tether
3845 can be replaced by a flexible rod having, for example threads
at a distal end. The threads of the rod can attach to corresponding
threads on the implant 3805. The threaded region of the implant can
be rotatable such that the implant 3805 can rotate perpendicular to
the guide catheter 3840 (see the position shown in FIG. 38B) in
order to couple and uncouple with the rod through rotational
threading and unthreading.
[0134] As shown in FIG. 38B, a second tether 3850 can be used to
longitudinally compress the spring 3820 between the platforms 3825,
3830 such that they approximate one another and the first portion
3810 receives a greater length of the second portion 3815 than it
receives in the uncompressed state and the overall length of the
device 3805 is reduced as defined by the distance between the
barbs. This second tether 3850 can thread through the guide
catheter 3840 in a similar manner as the first tether 3845 as
described above. The second tether 3850 can be tensioned to
compress the spring 3820 and after removal can be withdrawn
similarly as the first tether 3845. In an embodiment, a barb 3835
can be planted into a portion of the flailing valve leaflet and
another barb 3835 can be planted into the roof of the left atrium
LA. The barbs can be planted by actuating the distal curved section
of the guide catheter so as to guide the barbs 3835 into the
desired locations.
[0135] The device 3805 can exert a force between the atrium roof
and the valve leaflet through the spring 3820 to hold the leaflet
down and prevent flail up into the left atrium LA. The tension can
be adjusted by varying the spring coupled to the device prior to
inserting it into the body. Alternatively, the desired length of
the device after implantation can be adjusted and tuned prior to
introduction with an adjustable bolt and nut type design that
limits how far one platform can move in relation to the other. It
should be appreciated that the embodiments of chordal replacement
devices described herein are exemplary and that variations are
possible.
[0136] In another embodiment shown in FIGS. 39A-390, a chordal
replacement device 3905 can include a clip 3910, a distal anchor
3915 and a tether 3920 extending therebetween. The clip 3910 can
attach to a portion of a flailing leaflet LF and the distal anchor
3915 can extend into the ventricle such that the flailing leaflet
is held down. For example, the anchor 3915 can be implanted in the
left ventricular wall or septum or papillary head or other
appropriate tissue site. The length of the tether 3920 can be
variable and/or adjusted such that the tension applied to the
leaflet LF by the chordal replacement device 3905 is tailored to an
individual patient's needs. For example, once the clip 3910 is
positioned, the tether 3920 can be tensioned, tied and trimmed as
will be described in more detail below.
[0137] The clip 3910 can be an elastic element that can be deformed
to attach it to a portion of the leaflet LF, such as by crimping.
In an embodiment, the clip 3910 can be attached to a portion of the
valve leaflet LF where flail occurs, for example it can be fastened
to an edge of the anterior or posterior mitral valve leaflet with
the damaged chord. The clip 3910 can have surface feature 3950,
such as small barbs or a textured surface, that aids in the capture
of the leaflet LF upon deforming the clip 3910 to the leaflet LF.
As best shown in FIG. 39A, the clip 3910 can also include an
eyelet, aperture or other attachment feature 3945 that provides a
location for coupling to or extending the tether 3920 through a
portion of the clip 3910. The distal anchor 3915 can similarly
include an eyelet, aperture or attachment feature 3945 that
provides a location for the tether 3920 to couple to or extend
through a portion of the anchor 3915 (see FIG. 39A, for
example).
[0138] The anchor 3915 can vary in configuration and can include a
weight, barb, corkscrew, adhesive or other mechanism such that the
tether 3920 extends down and is secured in place within the
ventricle. In an embodiment, the anchor 3915 extends into the
ventricle from the clip 3910 and is secured to the bottom of the
ventricle or toward the ventricular septum or papillary head. In an
embodiment, the barbs of the anchor 3915 can be collapsible such
that they conform to a narrow configuration and fit within the
lumen of the guide catheter and expand upon being advanced out of
the guide catheter (see FIGS. 39B-39C).
[0139] As mentioned above, the tether 3920 can attach to the clip
3910 in a variety of ways. The clip 3910 can include an attachment
feature 3945 that provides a location for coupling the clip 3910 to
the tether 3920. For example and as shown in FIG. 39D-39H, a knot
or crimp 3930 can be applied to one end of the tether 3920 such
that end will lodge into a portion of the clip 3910 or will lodge
into the attachment feature 3945. The opposite, unknotted end of
the tether 3920 can extend through the delivery catheter 3960 and
be retracted until the crimp 3930 lodges with the attachment
feature 3945 on the clip 3910, which is attached to the leaflet LF.
The delivery catheter 3960 can be used to deploy the clip 3910 to
the leaflet (FIG. 39E) and can then be withdrawn (FIG. 39F). At
this stage the tether 3920 can still have both ends extending
outside the body (FIG. 39G). An anchor 3915 also coupled to the
tether 3920 can be loaded over the tether 3920 and delivered to the
ventricle as will be described in more detail below.
[0140] In another embodiment shown in FIG. 39J-39M, the delivery
system 3955 for the chordal replacement device 3905 can include a
guide catheter 3966 having a lumen 3965 for a clip delivery
catheter 3970 and a lumen 3975 for an anchor pusher or mandrel 3980
used to push the anchor 3915 out of the delivery system 3955. The
anchor 3915 is shown as a barbed anchor, but it should be
appreciated that other configurations are considered herein. The
anchor 3915 can be attached to a distal end of the mandrel 3980
such as by corresponding threads 3990 or another coupling
mechanism. Upon being pushed out the distal end of the guide
catheter 3966, the anchor 3915 can be uncoupled from the mandrel
3980 (such as by an unthreading rotation) and released in its
position within the heart. Alternatively, the anchor 3915 can be
unattached to the mandrel 3980 and simply pushed out the distal end
of the guide catheter 3966. Once the anchor 3915 is implanted, the
mandrel 3980 can be withdrawn.
[0141] It should be appreciated that the clip 3910 can be deployed
prior to, during or after delivery of the anchor 3915. The
embodiments of FIGS. 39D-39H and FIG. 39K illustrate the deployment
of the clip 3910 prior to the anchor 3915 being delivered. FIGS.
39L-39M illustrate an embodiment in which the clip 3910 is deployed
after the anchor 3915 is delivered.
[0142] As mentioned above, once the clip 3910 is positioned on the
leaflet LF and the anchor 3915 deployed and secured within the
ventricle, the tether 3920 can be tensioned. For example, the
tether 3920 can be pulled manually to tension an end of the tether
3920 extending outside the body, to the desired tension to hold the
leaflet LF down. Tension on the tether 3920 can be tuned and
adjusted until an appropriate tension on the leaflet LF is achieved
evidenced by the tether 3920 simulating the tension of a healthy
chord. The appropriate tension can be assessed as is known in the
art. For example, an echocardiogram can be performed to assess
leaflet flail or prolapse as well as the effect on mitral
regurgitation. Once the appropriate tension is achieved, the tether
3920 can be clamped and cut to remove the excess length of the
tether 3920. FIGS. 39N-390 illustrate an embodiment of a
dual-function cutting clamp 3935 having the tether 3920 extending
therethrough. The cutting clamp 3935 can have dual functions and
can be used to clamp onto the tether 3920 to secure it near the
distal end and it can also be used to cut the tether 3920 proximal
of the secured section. As best shown in FIG. 39O, the cutting
clamp 3935 can have an outer shell 3937 that can be coupled or
attached to the anchor 3915. The shell 3937 of the cutting clamp
3935 can have apertures or slots 3939 at opposite ends through
which the tether 3920 can extend into an inner region of the shell
3937. From one end of the shell 3937, the tether 3920 extends
towards the clip 3910. At the opposite end of the shell 3937, the
tether 3920 extends back through the delivery catheter 3970 to the
outside of the body. The cutting clamp 3935 can also include an
aperture or slot 3941 through which an actuator line 3943 can pass
and extend to the outside of the body. The actuator line 3943 can
be actuated to effect clamping and/or cutting of the tether 3920
with the cutting clamp 3935.
[0143] Still will respect to FIG. 39O, the cutting clamp 3935,
which may or may not already be coupled to the anchor 3915 can be
actuated such that the tether 3920 is engaged by a ratcheting clamp
mechanism. The ratcheting clamp mechanism prevents the release of
the tension on the tether 3920. The ratcheting clamp mechanism can
include opposing clamp elements 3946 that extend inward from a
ratchet recess 3947 open at an inner surface of the shell 3937. The
opposing clamp elements 3946 have textured surfaces at one end that
are designed to come together to releasably engage the tether 3920.
At an opposite end the opposing clamp elements 3946 can have a
ratchet mechanism 3949 that engages corresponding features in the
ratchet recess 3947 of the shell 3937. The opposing clamp elements
3946 can be actuated by pulling the actuator line 3943 at the
outside of the body. The actuator line 3943 engages the opposing
clamp elements 3946 such that they extend out from the ratchet
recess 3947 and approach one another until the tether 3920 is
caught between their textured surfaces. After the opposing clamp
elements 3946 are engaged with one another and the tension on the
tether 3920 is maintained, the actuation line 3943 can be actuated
further until the opposing cutting elements 3951 are engaged by the
actuation line 3943, extend from their respective ratchet recess
3947 until their cutting surfaces come in contact to cut the tether
3920 therebetween. Once the tether 3920 is cut by the opposing
cutting elements 3951 the actuation line 3943 can be released and
the loose end of the tether 3920 can be removed from outside the
body. In an embodiment, multiple chordal replacement devices 3905
can be used to attach to the chordae on the opposite or same side
as the flailing leaflet. The second chordal replacement device 3905
can incorporate a similar cutting clamp as described above.
[0144] In another embodiment as shown in FIG. 40A-40B, a chordal
replacement device 4005 can include a flexible material or patch
4010 that can be attached to the valve leaflet LF. A single strand
of artificial chordae 4015 can loop through and underneath the
patch 4010. The strand of artificial chordae 4015 can include one,
two, three or more individual loops and can be made of suture or
another flexible material. The loops of artificial chordae 4015 can
be drawn together at one end with a ring 4020 or other enclosed
shape going through the loops of artificial chordae 4015. The ring
4020 can be attached to the ventricle wall or papillary muscle or
ventricular septum with a distal attachment assembly as described
in more detail below.
[0145] The loops of artificial chordae 4015 can be a single strand
of material that freely slides through the patch 4010 and the ring
4020 such that the loops 4015 can self-equalize to evenly
distribute the load. A single loop 4015 can thread through the
patch 4010 and the ring 4020, for example three times, such that
one loop is short and there are two other loops that are long.
Pulling the ring 4020 away from the patch 4010 will engage the
short loop and redistribute the long loops to the length of the
shortest loop such that the three loops are equally long and
equally distribute the force. The loops of artificial chordae 4015
are not fixed such that they can slip and distribute the force
equally between them. This self-equalizing characteristic along
with the flexible patch 4010 reduces the stress on the leaflet
LF.
[0146] As shown in FIGS. 41A-41B, the device 4005 can be delivered
to the valve leaflet (posterior or anterior). The patch 4010 can be
folded and loaded into a delivery catheter 4025 such that the
artificial chordae 4015 trail behind and are delivered through a
guide catheter 4030 to the vicinity of the valve. A mandrel or
pusher tube 4035 can push the patch 4010 out the distal end of the
delivery catheter 4025 (see FIG. 41C).
[0147] The leaflet LF can be stabilized using a vacuum or a hook
attached to a guidewire or another stabilizing device. In an
embodiment shown in FIGS. 41G-41N, the leaflet LF can be captured
and/or stabilized using a guidewire 4141 having a distal end that
has a needle point. The needle point guidewire 4141 can be
delivered using a protective sheath or delivery catheter 4143 that
prevents pricking of the vessel as it is passed therethrough. The
sheath or delivery catheter 4143 can be retracted slightly exposing
the distal needle point to the leaflet LF. The distal needle point
can be urged through the leaflet LF near an edge or positioned
closer to the valve annulus. The needle point guidewire 4141 can be
pre-formed to have a hook shape such that when it is advanced out
of the sheath 4143 and extends through the leaflet LF it can curve
upward back toward the sheath 4143 to form a hook. In another
embodiment shown in FIGS. 41O-41P, the guidewire 4141 can include a
thicker needle point 4145 attached to a more flexible cable 4147 or
guidewire or thinner wire. The needle point 4145 can also be
preformed such that it takes on a sharper curve or hook shape when
advanced beyond the distal end of the delivery catheter 4143. The
needle point 4145 can be formed of a variety of materials such as
Nitinol or other shape memory alloy or other suitable material.
[0148] Tension can be applied to the needle point guidewire 4141
such that the leaflet LF remains hooked and stabilized.
Alternatively, the chordae can provide the resistance allowing the
needle point guidewire 4141 to puncture the leaflet LF. The needle
point guidewire 4141 as it forms the hook shape can penetrate the
leaflet LF a second time (see FIG. 41K) although it should be
appreciated that the guidewire need only penetrate the leaflet LF a
single time to effect capture and stabilization (see FIG. 41M). To
release the leaflet LF from the needle point guidewire 4141, the
sheath 4143 can be advanced distally back over the needle point as
shown in FIG. 41N. The portion of the guidewire 4141 penetrating
the leaflet LF is slowly withdrawn as the sheath 4143 is advanced
distally.
[0149] The patch 4010 can be affixed to the valve leaflet LF by
activating a leaflet attachment device 4040 through the guide
catheter 4030. In an embodiment, the leaflet attachment device 4040
can include a pair of expandable elements 4045 connected centrally
by a rod 4050. One or more of the expandable elements 4045 can have
a sharp needle point 4055. The patch 4010 can lie on top of the
valve leaflet LF and the sharp needle point 4055 of the leading
expandable element 4045 can pierce through the patch 4010 and the
leaflet LF such that the leading expandable element 4045 emerges
from the underneath side of the leaflet LF and the rod 4050 extends
through the leaflet (see FIGS. 41D and 41E). The patch 4010 on the
upper surface of the leaflet LF can be sandwiched between the
leading and trailing expandable elements 4045 of the leaflet
attachment device 4040. The leaflet attachment device 4040 and each
of the expandable elements 4045 can be a shape-memory metal (e.g.
Nitinol, Nitinol alloys) or some other spring material. The spring
material of the expandable elements 4045 allows them to spring out
as the leaflet attachment device 4040 is advanced from the distal
end of the delivery catheter 4025. The leaflet attachment can be
facilitated by stabilizing the leaflet as described above. The
position of the patch prior to securement of the expandable element
4045 can be maintained for example, by attaching the patch to the
first expandable element prior to being deployed from the delivery
catheter. The delivery catheter can then be used to maneuver into
position the patch prior to deploying the first expandable
element.
[0150] FIG. 41F shows a top view of an expandable element 4045
deployed on the upper surface of the leaflet. The embodiment is
shown having barbed arms in a star-shaped configuration although it
should be appreciated that other shapes and configurations are
considered. For example, as shown in FIGS. 42A-42B, the leaflet
attachment device 4040 can include expandable elements 4045 of a
spring metal mesh. The spring metal mesh expandable element 4045
can form a web shape and flatten out as it is deployed.
Alternatively, the Nitinol or other spring material can spring into
an expandable element 4045 shaped like a mesh ball (see FIG. 42C).
Upon expansion, the mesh ball expandable element 4045 can
protectively cover the sharp needle point 4055 on the underneath
side of the valve leaflet. It should also be appreciated that the
leaflet attachment device 4040 can include expandable elements 4045
that are a combination of configurations including flat mesh
design, ball mesh design, a star-shaped design or other
configuration. For example, one expandable element 4045 can have a
star-shaped design and the other expandable element 4045 can have a
mesh ball design (see FIG. 42D). The expandable devices such as the
mesh ball design can be collapsed sufficiently small to pass
through a needle hole without ripping the leaflet. In an
embodiment, the needle bore can be a larger hypotube such that
insertion of the tube needle can punch a hole in the leaflet. The
patch 4010 can cover the hole such that leaks are avoided. Further,
the hypotube can be dull at the base of the bore such that punched
out tissue remains attached to avoid creation of an embolism.
[0151] It should be appreciated that more than one leaflet
attachment device 4040 can be used to affix a patch 4010 to the
valve leaflet LF. As shown in FIG. 43A, the patch 4010 can be
attached to the atrial side of the valve leaflet LF with multiple
leaflet attachment devices 4040 oriented side-by-side on the upper
and lower surface of the leaflet LF. Using multiple leaflet
attachment devices 4040 to affix the patch 4010 reduces stress in
the leaflet LF, in part, due to distribution of forces across
multiple attachment locations. As shown in FIG. 43B, the multiple
leaflet attachment devices 4040 can be stacked and deployed in
series from a delivery catheter 4025. In another embodiment, the
multiple leaflet attachment devices 4040 can be deployed using a
guide wire between deployments of each leaflet attachment device
4040. For example, the patch 4010 can be deployed followed by the
first leaflet attachment device 4040. The delivery catheter 4025
can be withdrawn leaving a guide wire 4060 in place. Another
catheter with the second leaflet attachment device 4040 can then be
advanced along the guide wire 4060 and the second leaflet
attachment device 4040 deployed. The process can be repeated
depending on the number of attachment devices desired to be
deployed.
[0152] Once the patch 4010 is positioned and affixed to the leaflet
LF, such as with the leaflet attachment device(s) 4040, the loops
of artificial chordae 4015 can be deployed distally within the
ventricle such as to the ventricular wall, septum or papillary
muscle. As shown in FIG. 44A, the delivery catheter 4025 that
deployed the patch 4010 and leaflet attachment device(s) 4040 can
be removed from the guide catheter 4030 leaving a guide wire 4060
attached to a ring 4020 through which the artificial chordae 4015
loop (attachment device(s) are not shown in the figure for
simplicity). The guide wire 4060 can be previously looped through
the ring 4020, for example, during manufacturing. Another catheter
can be advanced over the guide wire 4060 through the guide catheter
4030. In an embodiment, the ring 4020 is attached to the distal end
of the catheter 4030 as shown in FIG. 44B-44C. For example, the
ring 4020 can be inserted or snapped into a flanged channel 4065
near the distal end of the catheter 4030 using the guide wire 4060
looped through the ring 4020. The catheter 4030 with the ring 4020
in the channel 4065 can advance through the valve distally into the
ventricle (see FIG. 44D).
[0153] As shown in FIGS. 45A-45D, the ring 4020 with the attached
loops of artificial chordae 4015 can be anchored to the ventricular
wall or papillary muscle forming a distal attachment assembly 4070
of the chordal replacement device. In an embodiment a coil screw
4075 is coupled to the distal attachment assembly 4070. The coil
screw 4075 can be advanced like a cork screw through the distal end
of the catheter 4030 into the ventricular tissue, for example, by
rotating an actuator knob on the proximal end of the catheter. The
rotation of the actuator knob can rotate the coil screw, advancing
it out of the catheter and into the ventricular tissue.
[0154] In another embodiment, the distal attachment assembly 4070
can be coupled to or can include a fillable element 4080 delivered
through a hollow needle 4085 that pierces the ventricular wall (See
FIGS. 45B-45C). The fillable element 4080 can include a balloon or
mesh bag or other expandable element. A hardening agent or other
material can be used to fill the element 4080 expanding it such
that it anchors the artificial chordae 4015 and the distal
attachment assembly 4070 to the ventricle. The needle 4085 can be
retracted leaving the filled element 4080 inserted in the ventricle
wall and coupled to the distal attachment assembly 4070. The
hardening agent can be a two-part hardening agent, such that a
small quantity of a second agent can be delivered through another
smaller tube in the catheter to activate the first part and main
bulk of the hardening agent.
[0155] After the distal anchor (e.g. coil screw 4075 or filled
element 4080) of the distal attachment assembly 4070 is attached to
the ventricular wall or papillary muscle, the distal attachment
assembly 4070 can be released from the guide catheter 4030. The
assembly 4070 can be released, for example, using a mandrel that
runs through the catheter and has a threaded end that threads into
the distal attachment assembly. In another embodiment, the distal
end of the catheter can be a sleeve that pinches circumferentially
onto the attachment assembly and then by retracting a lever
proximally, a mandrel is retracted which pulls the pinching sleeve
backwards over the catheter slightly, expanding the pinching sleeve
and releasing the attachment assembly. The two ends of the guide
wire 4060 can extend all the way up through the guide catheter
4030. As the delivery catheter 4025 is removed, the guide wire 4060
can still be looped through the ring 4020. The guide wire 4060 can
be removed before, during or after the delivery catheter 4025 is
removed. The guide wire 4060 can be removed by pulling one end,
allowing the trailing end to pull through the ring 4020 and then
out of the guide catheter 4030 leaving the distal attachment
assembly 4070 anchored in the ventricle and the artificial chordae
4015 extending up to the valve leaflet LF where the patch 4010 is
affixed to the leaflet LF with the leaflet attachment device(s)
4040.
[0156] Once the chordal replacement device is deployed, the tension
of the artificial chordae 4015 can be adjusted. In an embodiment, a
sensor 4090 such as a pin or pressure sensor can be used to adjust
tension in the artificial chordae 4015. The sensor 4090 can provide
the user with information regarding contact between the guide
catheter 4030 and the ventricular wall. As shown in FIG. 46A-46B,
the sensor 4090 can include a pin 4095 near the distal tip of the
catheter 4030. The pin 4095 is shown in FIG. 46A as fully extended
indicating no contact with the ventricular wall. Upon contact with
the wall as shown in FIG. 46B, the pin 4095 can compress and
activate delivery of a signal to the user such as an electrical
signal or visual signal indicating that contact is made with the
wall of the ventricle. If the sensor 4090 indicates contact with
the ventricular wall and an echocardiogram suggests no flail or
prolapse and mitral regurgitation (MR) is reduced then the distal
anchor (e.g. coil screw 4075 or element 4080) can be advanced into
the ventricular wall to secure attachment. If the sensor 4090
indicates contact with the ventricular wall, but the echocardiogram
suggests flail and/or prolapse and poor MR results, the catheter
4030 can be moved further down into the ventricle to increase
tension on the artificial chordae 4015 and the test repeated. If
the sensor 4090 indicates contact with the ventricular wall, and
the echocardiogram suggests no flail and/or prolapse but the MR
results are still poor, the leaflet is pulled down too far and the
catheter 4030 can be moved proximally to release tension on the
artificial chordae 4015. The test can be repeated until desirable
results are achieved.
[0157] Once the distal anchor is advanced into the ventricular wall
and adequate results are obtained, fine-tuning of the tension can
be performed (see FIG. 47). In an embodiment, the distal anchor can
be a coil screw 4075 that is advanced and locked. The distal
attachment assembly 4070 can be rotated clockwise by the catheter
4030 to draw the ring 4020 slightly closer to the ventricular wall.
The distal attachment assembly 4070 can also be rotated by the
catheter 4030 in a counter-clockwise direction to push the ring
4020 away such that the valve leaflet LF can rise up slightly.
[0158] In another embodiment as shown in FIGS. 48A-48B, the distal
anchor can be an expandable element, such as a balloon anchor
filled with a two-part epoxy as described above. This embodiment
can also be fine-tuned. As the expandable element 4080 expands
within the ventricular wall, the distal attachment assembly 4070
attached to the expandable element 4080 is pulled toward the
ventricular wall. The material of the expandable element 4080 can
be finitely expanded such that fine-tuning of the distance between
the distal attachment assembly 4070 and the ventricular wall can be
performed. As the expandable element 4080 is unexpanded the
artificial chordae 4015 can pull the distal attachment assembly
4070 away from ventricular wall and the valve leaflet can rise
slightly. Once gross adjustments are performed, fine-tuning the
tension on the artificial chordae 4015 attached to the valve
leaflet can be performed. The first part epoxy (i.e. prior to
hardening) can be used to fill the expandable element 4080 and also
fine-tune the positioning and tension on the chordae 4015. Once the
proper position is confirmed, the second part of the epoxy can be
infused such that it hardens and sets in place the chordae. It
should be appreciated that the epoxy can be embedded directly into
the attachment site or can be used to fill a expandable element
pre-embedded in the distal attachment site. Ideally, very little of
the second part epoxy is used so as not to interfere with the
fine-tuning achieved.
[0159] The chordal replacement device need not include a distal
attachment assembly 4070 (see FIGS. 49A-49B). For example, the
chordal replacement device can be attached to an attachment
assembly that is deployed proximal to the valve. In an embodiment,
the chordal replacement device can include a ring 4020 and loops of
artificial chordae 4015 attached to a rod 4105 extending from a
spring material (e.g. shape-memory metal such as Nitinol or other
material) that forms a stent-like mesh 4100 deployed in the left
atrium, just above the mitral valve. The rod 4105 can be attached
to the mesh 4100 and extend from the mesh 4100 through the mitral
valve such as at one of the commissures into the ventricle. The rod
4105 can be straight or curved or jointed. The distal end of the
rod 4105 can be attached to the ring 4020 such as by extending
through the ring 4020. Rod 4105 and mesh 4100 can be moved to
adjust tension on the artificial chordae 4015. Once in a desirable
location and the desired tension is achieved, the mesh 4100 and rod
4105 can be secured within the atrium or to the valve leaflets, for
example using the leaflet attachment devices 4040 discussed above
(see FIG. 49B; note the rod, ring and replacement chordae are not
shown).
[0160] As shown in FIG. 50A, the rod 4105 and mesh 4100 can be
delivered through a delivery catheter 4025 in which the mesh 4100
is collapsed. As mentioned above, the rod 4105 can be jointed. The
joints 4110 can lock in place once the rod 4105 is deployed and/or
can have limited travel around the joint 4110. As shown in FIGS.
50C-50E, one or more of the rod joints 4110 can lock into place
using a mechanical/physical feature incorporated within the joint
4110. In an embodiment, one or more of the joints 4110 can have a
surface feature 4112 such that when the rod 4105 rotates over the
surface feature 4112 on the adjacent portion of the joint 4110 it
can pop over and lock in place relative to the adjacent portion of
the joint 4110.
[0161] Even in the locked position, one or more of the joints 4110
can have limited travel around the joint 4110 to provide the
artificial chordae 4015 with some degree of slack (see FIG. 50B).
The rod 4105 and mesh 4100 can passively rise and fall with the
mitral annulus during the cardiac cycle. In diastole, when the
annulus rises, excessive tension on the artificial chordae 4015 can
be avoided due to this limited travel around the joint 4110. In an
embodiment, the top joint 4110 can lock and the bottom joint does
not lock. In this embodiment, the lower joint can pivot without
detriment to the system as the annulus rises during diastole.
During systole, the lower joint can pivot in the opposite direction
due to tension on the chordae until the physical stop incorporated
in the joint limits the travel. In this position the rod system can
then provide tension to the chordae and hold the leaflets down. As
shown in FIG. 50F, the top joint 4110 rather than being fixed can
pivot about an axis that is orthogonal to the axis of the bottom
joint. This arrangement can prevent the forces of the cardiac cycle
from bending the top joint once deployed.
[0162] With reference to FIGS. 51A-51B, rather than using a jointed
rod, the rod 4105 can be flexible so that it can fit in a delivery
catheter 4025 and expand to its spring-formed shape when deployed
from the delivery catheter 4025. Flexibility of rod 4105 can be
designed so that it provides a predictable spring force on the
artificial chordae 4015. The rod 4105 can deflect and provide
consistent tension on the artificial chordae 4015.
[0163] It should be appreciated that in addition to a chordal
replacement system, the leaflet attachment devices 4040 described
above can be used to attach a leaflet extension patch for the
treatment of mitral valve prolapse or flail. As shown in FIGS.
52A-52C, the leaflet extension patch 5210 can be attached to the
atrial side of the valve leaflet. The leaflet extension patch 5210
can be a stiff or a flexible material. The leaflet extension patch
5210 can prevent mitral regurgitation in the case of prolapse or
flail in that it can block the leaflet from flailing upwards into
the atrium. For functional mitral regurgitation, the leaflet
extension patch 5210 can bridge any coaptation gap between the
leaflets.
[0164] FIG. 52A shows the leaflet extension patch 5210 during
diastole. The patch 5210 can follow the leaflet downwards such that
flow through the valve is not impeded. During systole, the leaflet
extension patch 5210 can block flow by coapting with the opposite
leaflet LF as well as prevent flail or prolapse by physically
blocking it from moving upwards into the atrium (see FIGS. 52B and
52C).
[0165] Other embodiments are directed to atrial or ventricular
remodeling to alter the shape of an atrium or ventricle. Now with
respect to FIG. 14 which shows a cross-sectional view of the heart
with a first and second anchor attached to a wall of the heart. The
system includes a first anchor 1410a having a screw portion 1415
for screwing into a wall of the heart and a connector portion. The
connector portion is rotatable around an axis of rotation. The
first anchor includes a power source to power rotation of the
connector portion and a receiver for receiving telemetric signals
from an external controller for controlling the rotation of the
connector portion. The system includes a second anchor 1410b having
a screw portion 1415b for screwing into a wall of the heart and a
connector portion. Also included is a tether 1420 having two free
ends. One of the free ends is coupled to the connector portion of
the first anchor, and the other free end is coupled to the
connector portion of the second anchor. An external controller is
also included. The external controller has a telemetric transmitter
for communicating with the receiver and controls the rotation of
the connector portion. Alternatively, the anchors may be placed
with a torqueable catheter.
[0166] In another embodiment, a method of altering a geometry of a
heart includes introducing a first coupler into a heart chamber.
The first coupler has an anchor portion and a connector portion.
The connector portion is rotatable around an axis of rotation and
is connected to a power source to power rotation of the connector
portion. The power source is in communication with a telemetric
signal receiver. The first coupler is secured to the wall of the
heart chamber by anchoring the anchor portion to the wall. A second
coupler is introduced into the heart chamber. The second coupler
includes an anchor portion and a connector portion. The second
coupler is secured to the wall of the heart chamber by anchoring
the anchor portion to the wall at a distance from the first
coupler.
[0167] A tensile member is introduced into the heart chamber. One
end of the tensile member is connected to the connector portion of
the first coupler, and another end of the tensile member is
connected to the connector portion of the second coupler. The
distance between the first and second couplers is adjusted by
transmitting a telemetric signal to the receiver, thus causing the
connector portion to rotate around the axis of rotation and
threading the tensile member around the connector portion to reduce
the distance between the first and second couplers.
[0168] In another embodiment, a system for altering the geometry of
a heart chamber includes a planar tensile member having
substantially inelastic material. At least two anchors are included
for anchoring the planar tensile member to an inner wall of a heart
chamber. The planar tensile member is substantially shorter in
length than a left ventricle of a heart so that when the planar
tensile member is anchored in a caudal direction along a length of
the left ventricle a tensile force exerted by the planar tensile
member between the two anchors prevents the left ventricle from
dilating caudally.
[0169] In another embodiment, a method for altering the geometry of
a heart includes providing a tensile member having a substantially
inelastic material. The tensile member is substantially shorter in
length than a left ventricle of a heart. The tensile member is
inserted into the left ventricle of the heart and a proximal end of
the tensile member is anchored to the left ventricle adjacent the
mitral valve. A distal end of the tensile member is anchored to the
left ventricle caudal the proximal end so that a tensile force
exerted by the tensile member between the two anchors prevents the
left ventricle from dilating caudally.
[0170] Other embodiments are directed to strengthening or reshaping
the left ventricle of the heart. In one embodiment in particular, a
method of reinforcing the left ventricle includes injecting a
strengthening agent into a wall of the left ventricle in an
enlarged region of the ventricle, as shown in FIG. 15. FIG. 15
shows a catheter 1510 that has been introduced into the heart. The
catheter 1510 has an internal lumen through which the strengthening
agent 1512 can be injected. A proximal end of the catheter is
connected to a source of the strengthening agent and a distal end
of the catheter is configured to release the strengthening agent.
As shown in FIG. 15, the distal end of the catheter is positioned
at or near a wall of the heart and the strengthening agent 1512 is
injected into the wall of the heart.
[0171] In another embodiment, a method is directed to altering the
geometry of a heart. The method includes injecting a polymerizing
agent into a pericardial space adjacent a left ventricle, thereby
exerting a medial (inward) force against the left ventricle.
[0172] In yet another embodiment, a method of altering the geometry
of a heart includes inserting a balloon into a pericardial space
adjacent to a left ventricle of the heart, or extend into the
pericardium of the heart. The balloon is inflated by injecting it
with a fluid, and it exerts a medial force against the left
ventricle upon inflation. In certain embodiments, the balloon can
be inflated at the time of implantation, or at a later time. If
inflated at a later time, the balloon would be self-sealing, and
may be inflated by accessing the balloon with a needle placed
through the chest wall.
[0173] Other embodiments are directed to adjusting the length or
orientation of papillary muscles. FIG. 16 shows a schematic view of
the heart showing the papillary muscles PM. With reference to FIG.
16, a method of treating heart disease includes inserting an
anchor, cuff or sleeve 1205 into the left ventricle of an
individual's heart, and sliding a cuff or sleeve around a papillary
muscle PM. The size of the cuff or sleeve is reduced so that the
cuff or sleeve squeezes the papillary muscle. As the size of the
cuff or sleeve is reduced, the papillary muscle stretches and
increased in length.
[0174] In yet another embodiment, a method of treating heart
disease includes obtaining access to a papillary muscle in a left
ventricle of the heart. The papillary muscle is cut and reattached
at a new location on an inner wall of the ventricle closer to the
mitral valve.
[0175] Additional embodiments that employ magnets in the heart are
now described with reference to FIGS. 17-19, which show
cross-sectional views of the heart. With reference to FIG. 17, in
one embodiment one or more magnets 1705 are implanted or otherwise
attached to a wall 1710 of the left ventricle LV. One or more other
magnets 1715 are implanted or otherwise attached to a wall 1720 of
the right ventricle. The magnets 1705 and 1715 are attached to the
walls 1710 and 1720 such that they assert an attractive magnetic
force (as represented by the arrows 1725 in FIG. 17) toward each
other. The magnetic force 1725 assists in remodeling of the left
ventricle during pumping of the heart. That is, the magnets 1705
and 1715 are urged toward one another (thereby also urging the
walls 1710 and 1720 toward one another) to re-shape either the
annulus AN or the left ventricle LV. The annulus or the left
ventricle LV are re-shaped in a manner that reduces or eliminates
backflow through the mitral valve MV. It should be appreciated that
a similar procedure can be performed on the right ventricle RV and
associated valves.
[0176] FIG. 18A shows another embodiment of a procedure wherein
magnets are implanted in the heart to geometrically reshape the
annulus or the left ventricle. One or more magnets 1705 are
implanted or otherwise attached to a first wall 1710a of the left
ventricle LV. One or more magnets 1705 are also implanted or
otherwise attached to a second, opposed wall 1710b of the left
ventricle. The magnets on the opposed walls 1710a, 1710b exert an
attractive magnetic force toward one another to draw the walls
1710a, 1710b toward one another and re-shape the left ventricle LV
or the annulus AN.
[0177] Another embodiment of a procedure uses magnets to anchor
tethers within the heart at various locations to optimize the shape
of cardiac structures to improve cardiac function. The tethers are
placed to either reshape the cardiac structure or to prevent
dilatation of the structure over time. The tethers must be securely
anchored to the heart structures. A method of anchoring which
enables tethering in various positions and directions within the
cardiac structures is important for the clinician to optimize
cardiac reshaping based on each individual patient anatomy and
disease state. A method of anchoring which is atraumatic is also
desirable.
[0178] FIG. 18B shows a side view of the heart with sets of magnets
A, A1, B, and B1 positioned to various locations of the heart or to
anatomical structures adjacent the heart. In one embodiment, at
least one magnet A is placed on the interventricular septum within
the right ventricle RV. At least one magnet A1 is placed within the
left ventricle LV opposite magnet A. The magnetic force between A
and A1 maintains the position of the magnets. The magnets may be
enclosed in materials that will promote tissue in-growth and
healing to the interventricular septum to ensure stability of
location and to eliminate the need for long term anti-coagulation.
Additionally, the enclosure material which is flexible and can be
delivered in a low profile can be significantly larger in size than
the magnets to increase the surface area of contact with the heart
wall which will increase the tension that can ultimately be placed
on the anchor over time.
[0179] A second set of magnets B and B1 are then delivered to
another location selected within or adjacent to the heart. The set
of magnets A/A1 are attached to the set of magnets B/B1 using at
least one tether 1805, as shown in FIG. 18B. The tether 1805 can be
attached to either or both of the magnets A/A1 at one end and to
either of both of the magnets B/B1 at an opposite end. When the set
of magnets B/B1 are tethered under tension to the set of magnets
A/A1, a change in the shape of the cardiac structure results to
improve cardiac function. FIG. 18B shows magnet B positioned in the
LV and B1 positioned in a blood vessel BV adjacent to the heart.
The magnetic force between B and B1 maintains the location of B and
B1. Magnets B and B1 are delivered on or within materials and
structures which promote healing and increase the amount of tension
that can be placed on the anchor over time. For example, magnet B1
can be delivered on a stent which is of a length, diameter and
material which will heal within the BV to provide sufficient
resistance to forces placed on it by the tethers.
[0180] The tethers may be pre-attached to the magnets A and B1 or
they may be attached after A and B1 have been positioned. The
tether length may be shortened and/or adjusted after placement of
the anchors. Alternatively the final tether length may be
pre-selected based on the patient's cardiac structure geometry and
the effect the clinician desires. Placing sets of magnets in this
method, enables anchoring of tethers within the heart in various
positions and angles which provides increased flexibility and
variation for clinicians to select optimal re-shaping of the
cardiac structures based on specific patient characteristics.
[0181] Examples which demonstrate the flexibility of this approach
include placing anchors at the annulus and at the apex of the heart
and tethered to shorten the length of the LV; anchors can be placed
in the around the annulus and tethered to change the shape of the
annulus. More specifically, one or more sets of magnets can be
placed in the RA and LA at the level of the mitral valve annulus
(on the anterior side of the annulus) and one or more sets of
magnets can be placed in the LA and LV on opposite sides of the
annulus on the posterior portion of the annulus. The posterior sets
of magnets can then be tethered to the anterior sets of magnets to
change the shape of the annulus. Alternatively, the magnet anchors
can be placed at the level of the annulus in the LA and in a BV
adjacent to the heart at the level of the annulus and these then
tethered to the anterior annulus magnet anchor described above.
[0182] The magnets A and A1 can also be a single magnet that
extends through the interventricular septum. Moreover, only one of
the magnets A or A1 need be implanted. One or more magnets B and/or
B2 are located opposite the location of the magnet(s) A and/or A1.
The magnet(s) B is located within the left ventricle opposite the
magnets A/A1, such as on the left ventricular wall. The magnet B1
is located on an anatomical structure adjacent the heart, such as
on a blood vessel BV.
[0183] In another embodiment shown in FIG. 18C, the magnets A, A1,
B, and B1, or combinations thereof, are implanted in the heart
without tethers. The magnets A, A1, B, and B1 can be positioned in
various combinations so as to exert magnetic attractions to one
another to re-shape the left ventricle or the mitral valve annulus.
For example, the magnets A and B can be implanted such that they
exert an attractive magnetic force relative to one another. The
magnets A and B2 can alternately be implanted. Other possible
combinations are the magnets A1 and B or the magnets A1 and B2. The
magnets can be implanted without tethers such that an attractive
magnetic force F causes the magnets and the attached region of the
heart to move toward one another to re-shape the heart.
Alternately, the magnets can be attached to one another with
tethers.
[0184] In yet another embodiment, one or more magnets 1705 are
implanted in the walls 1710 of the left ventricle LV and/or the
right ventricle RV, as shown in FIG. 19. The magnets 1705 are
positioned in opposed locations on the walls 1710 and one or more
tethers 1905 attach opposed pairs of magnets 1705 to one another.
One or more of the tethers 1905 extend through the interventricular
septum to connect a first magnet disposed in the left ventricle and
a second magnet disposed in the right ventricle. In certain
embodiments, magnet elements do not include tethers, but rely on
the magnetic attraction to each other to remodel the tissue between
them. For example, a magnetic element may be placed on either side
of the interventricular septum, or one element within the septum.
Another magnetic element may be placed on or within the opposite
left ventricular wall, or in an adjacent vessel on the left
ventricular wall. The electromagnetic field of such elements can
then interact to cause a remodeling of the left ventricle to assist
with ventricular function.
[0185] The tethers 1905 can be elastic so to exert an attractive
force between the attached magnets 1705 and re-shape the left
ventricle LV or annulus AN. Alternately, or in combination with
elastic tethers, the tethers 1905 can be shortened in length after
placement to thereby pull the walls of the left ventricle LV toward
one another and re-shape the left ventricle LV or the annulus AN.
In combination with the force provided by the tethers 1905, the
magnets 1705 exert an attractive magnetic force toward one another
to assist in pulling the heart walls toward each other.
[0186] It should be appreciated that one or more magnets can be
positioned in other locations of the heart or adjacent anatomical
structures for re-shaping of the heart. For example, one or more
magnets can be positioned around the annulus AN or can be
positioned in the coronary sinus in such a manner that the magnets
exert attractive forces toward one another to cause re-shaping of a
desired portion of the heart.
[0187] In another embodiment, cardiac re-shaping is achieved
through percutaneous placement of one or more tethers that are
cinched or anchored in the walls of the left ventricle LV. The
tethers provide tension between the walls of the left ventricle to
reshape the left ventricle LV in a desired manner. FIG. 20 shows a
cross-sectional view of the left ventricle LV with a tether 2010
positioned therein. The tether 2010 has a first end anchored to a
first wall of the left ventricle LV and a second end anchored to an
opposed wall of the left ventricle LV. The tether 2010 is tensioned
to pull the walls toward one another (as represented by the phantom
lines 2012 in FIG. 20) and re-shape the left ventricle LV. It
should be appreciated that the phantom lines 2012 in FIG. 20 are
merely representative of the geometric re-shaping. The left
ventricle LV can be re-shaped in various manners and the amount of
re-shaping can vary depending on the tension applied to the tether
2010 and the location of attachment to the walls of the left
ventricle LV. The tether may be inelastic or somewhat elastic.
[0188] The tether 2010 can be anchored or otherwise attached to the
walls in various manners. In an exemplary embodiment, a patch 2015
(shown in FIG. 20) of material is positioned on an exterior surface
of the ventricular wall and is attached to one end of the tether
2010. A similar patch can also be positioned on the opposed wall
and attached to the opposite end of the tether.
[0189] With reference to FIG. 21, the patch is delivered to a
desired location using a catheter 2105 having a sharpened distal
end 2110 that is positioned within the left ventricle LV. The
catheter 2105 can be delivered to the left ventricle LV in various
manners, including trans-aortically (via the aorta), trans-septally
(by piercing the interventricular septum), and trans-atrially (via
the left atrium LA) pursuant to well-known methods. As shown in
FIG. 22, the sharpened distal end 2110 pierces the ventricular wall
such that the distal end 2110 is positioned exterior to the
ventricular wall. The catheter 2105 has an internal delivery lumen
having an opening at the distal end 2110. The patch 2015 is
configured to be transported in a contracted state through the
delivery lumen and delivered out of the opening at the distal end
2110, where the patch 2015 expands into an expanded state at the
exterior of the ventricular wall to seal against the exterior of
the left ventricular wall.
[0190] When positioned at the exterior of the ventricular wall, the
patch 2015 is configured to act as a reservoir that receives a
fluid material that can be delivered to the patch via the delivery
lumen of the catheter 2105. The fluid material has a first viscous
state of sufficient fluidity such that the material can flow
through the delivery lumen of the catheter 2105 and out of the
distal end 2110 to the location of the patch 2015. The fluid
material changes to a second viscous state when positioned exterior
to the ventricular wall at the patch 2015. The second viscous state
is of greater viscosity (i.e., more resistant to flow) than the
first viscous state such that the fluid material provides support
and a level of rigidity to the patch 2015 and to the left
ventricular wall. The fluid material can change to the second
viscous state after a predetermined time period, after contact with
the patch, or when the patch is completely filled. A catalyst can
be injected into the fluid material to cause it to change to the
second viscous state.
[0191] As shown in FIG. 23, the catheter 2105 can then be
disengaged from the patch 2015 such that the patch 2015 is disposed
exterior to the ventricular wall. The patch 2015 can be firmly
attached to the ventricular wall (such as using an adhesive) to
minimize wear or friction between the patch and the ventricular
wall. Next, an end of the tether 2010 is attached to the patch
2015. The catheter 2105 can be used to deliver the tether 2010 to
the patch 2015 or, alternately, a second catheter can be used. In
one embodiment, the tether 2010 is already positioned in a delivery
lumen of the catheter 2105 while the patch 2015 is being delivered.
The catheter 2105 is then pulled back while the end of the tether
2010 remains attached to the patch 2015 to thereby let the tether
2010 out from the catheter 2105, as shown in FIG. 23.
[0192] With reference now to FIG. 24, a second patch 2415 is
deployed in or exterior to an opposed ventricular wall in a manner
similar to that described above. The opposite end of the tether
2010 is then attached to the second patch 2415 such that the tether
2010 extends between the two patches, as shown in FIG. 20.
Alternately, as shown in FIG. 24, a second tether 2420 is attached
at a first end to the second patch 2415. As shown in FIG. 25, the
two tethers 2010 and 2420 can then be attached together at opposite
ends from the patches, such as by using a clip 2510, to form a
single attachment tether between the patches 2015 and 2415. The
tethers 2010 and 2420 can be twisted or adjusted within the clip
2510 to tension the resulting attachment tether between the patches
2415 and 2015 and pull the ventricular walls toward one another via
the tether. Once properly tensioned, the tether can be clipped or
clamped to maintain its position.
[0193] In another embodiment, shown in FIG. 26, a needle 2610 or
delivery catheter is passed trans-thoracically into the left
ventricle LV to deliver a patch 2615 to the exterior of the
ventricular wall, as described above. A sealing means, such as a
sealing balloon, can be used to seal one or more puncture holes in
the wall of the left ventricle caused by the needle 2610 during
delivery of the patch 2615. Visualization means, such as
fluoroscopy, can be used to visualize proper placement of the
needle 2610. A second patch is attached to an opposed wall to form
a tether attachment between the walls, as shown in FIG. 20. The
tether is then tensioned to pull the walls together and re-shape
the left ventricle or annulus of the mitral valve in a desired
manner.
[0194] In other embodiments, described with reference to FIGS.
27-31, cardiac re-shaping is achieved by manipulation of the
papillary muscles. FIG. 27 shows a schematic, cross-sectional view
of the left ventricle LV in a healthy state with the mitral valve
closed. The valve chordae CH connect the leaflets LF of the mitral
valve to the papillary muscles PM. The papillary muscles PM and the
and chordae CH are positioned such that at least a portion of the
leaflets LF contact one another when the mitral valve is in the
closed state, resulting in functional coaptation of the
leaflets.
[0195] FIG. 28 shows the left ventricle LV in a dysfunctional
state. The valve chordae CH or the papillary muscles PM are damaged
or otherwise dysfunctional such that the leaflets LF do not
properly coapt (contact one another). The dysfunction can be
manifested by excess tension in the chordae CH such that a gap is
located between the leaflets LF, or in some cases one leaflet may
function at a different level from the other (e.g. lower (prolapse)
or higher (flail)) thereby limiting the ability of the mitral valve
to close resulting in mitral regurgitation. The dysfunctional left
ventricle LV and in some cases leaflet prolapse or flail, can be
treated by manipulating papillary muscles PM to adjust the position
of the leaflets LF. In one embodiment, the papillary muscles PM are
repositioned toward one another to reduce the distance between the
papillary muscles PM.
[0196] In an embodiment described with reference to FIG. 29, a
biasing member, such as a rod of adjustable length, or a spring
2910, is mounted between the papillary muscles PM with a first end
of the spring 2910 attached to a first papillary muscle and a
second end of the spring 2910 attached to a second papillary
muscle. The spring 2910 has a pre-load such that the spring 2910
provides a biasing force (represented by the arrows 2915 in FIG.
29) that pulls the papillary muscles PM toward one another. Such a
spring may be covered with polyester fabric or other coating to
promote ingrowth into the muscle tissue and minimize the potential
for clot formation. The repositioning of the papillary muscles PM
re-shapes the left ventricle and/or changes the distance that the
leaflets need to move on the chordae CH such that the leaflets LF
contact one another to close the mitral valve. The tension provided
by the spring 2910 can be varied or different springs can be used
to achieve a proper repositioning of the papillary muscles PM. The
tension may be modified at the time of the procedure or during a
subsequent procedure if it is determined that additional coaptation
is required.
[0197] In another embodiment, described with reference to FIG. 30,
a suture 3010 is mounted between the papillary muscles PM with a
first end of the suture 3010 attached to a first papillary muscle
and a second end of the suture 3010 attached to a second papillary
muscle. The suture 3010 can be attached to the papillary muscles in
various manners. For example, an attachment device 3015, such as an
anchor, cuff or sleeve, can be positioned around or partially
around each of the papillary muscles. The ends of the suture 3010
are attached to the attachment devices 3015 to secure the suture
3010 to the suture to the papillary muscles.
[0198] The suture 3010 is tensioned such that it provides a force
that pulls the papillary muscles PM toward one another. The suture
3010 can be tensioned, for example, by twisting the suture 3010 to
reduce its the overall length and thereby reduce the distance
between the papillary muscles PM, and fixing the suture with a
crimping element or other stay element. The amount of twisting or
shortening can be varied to vary the tension provided by the suture
3010. In addition, a crimping member may be used to fix the sutures
once a desired tension between the muscles is reached. Exemplary
crimping members are described in International Patent Publication
Number WO 2003/073913, which is incorporated herein by reference in
its entirety. As in the previous embodiment, the repositioning of
the papillary muscles PM re-shapes the left ventricle and/or
changes the tension on the chordae CH such that the leaflets LF
contact one another to close the mitral valve. Cuffs or sleeves may
be placed around the papillary muscles PM to such as those
previously described, to affect the repositioning.
[0199] With reference now to FIG. 31, the papillary muscles PM can
also be repositioned by snaring the papillary muscles. A snare 3110
comprised of a looped strand of material is positioned around the
chordae CH at or near the location where the chordae attach with
the papillary muscles PM. The snare 3110 is tightened to draw the
papillary muscles PM toward one another and re-shape the left
ventricle and/or changes the distance that the leaflets need to
travel during systole such that the leaflets LF contact one another
to close the mitral valve.
[0200] In yet another embodiment, shown in FIG. 36, one or more
clips 3610 are clipped to each of the papillary muscles PM. The
structure of the clips 3610 can vary. A tether 3615 attaches the
clips 3610 to one another. The tether 3615 is cinched to shorten
the length of the tether 3615 and pull the papillary muscles PM
toward one another and re-shape the left ventricle and/or changes
the distance that the leaflets need to travel during systole such
that the leaflets LF contact one another to close the mitral
valve.
[0201] In yet another embodiment, shown in FIG. 37, one or more
clips 3610 are clipped to opposed walls of the left ventricle LV.
The clips 3610 can be delivered to the left ventricle using a
delivery catheter 2105. A tether attaches the clips to one another.
The tether is cinched to shorten the length of the tether and pull
the ventricular walls toward one another and re-shape the left
ventricle and/or changes the distance that the leaflets need to
travel during systole such that the leaflets LF contact one another
to close the mitral valve.
[0202] In all embodiments, once the papillary muscles are fixed or
repositioned, it may be advantageous to further treat the area by
selectively elongating or shortening the chordae tendinae to
achieve further optimal valve function. In addition, a mitral valve
clip may be deployed to augment the desired valve function, either
before papillary or chordal manipulation, or after, if the desired
leaflet coaptation is not achieved with one particular
approach.
[0203] As discussed above with reference to FIG. 28, a
dysfunctional left ventricle can be manifested by excess tension in
the chordae CH such that a gap is positioned between the valve
leaflets LF. It can be desirable to eliminate or relieve the excess
tension by cutting the chordae CH, and/or cutting the chordae and
replacing them with artificial chordae. Prior to cutting the
chordae, it can be desirable to evaluate the placement of the
artificial chordae to confirm that implantation of the chordae will
indeed provide the desired clinical result. This process is now
described with reference to FIGS. 32-35.
[0204] FIG. 32 shows a leaflet grasping device 1100 that is
configured to grasp and secure the leaflets of the mitral valve.
The device 1100 and corresponding methods of use are described in
more detail in U.S. Patent Publication No. 2004/0030382, entitled
"Methods and Apparatus For Cardiac Valve Repair", which is
incorporated herein by reference in its entirety. Additional
leaflet grasping devices are described in U.S. Patent Publication
No. 2004/0092962, U.S. Pat. No. 6,269,819, issued Aug. 7, 2001, and
U.S. U.S. Pat. No. 6,461,366, issued Oct. 8, 2002, all of which are
expressly incorporated by reference herein.
[0205] Referring to FIG. 32, the device 1100 is comprised of a
catheter shaft 1102 having a distal end 1104 and a proximal end
1106. The catheter shaft 1102 is comprised of, among others, a
conduit 1108, a coaxial outer sheath 1110, a central lumen 1111
through which a double-jaw grasper 1113 may be inserted, and a
central guidewire lumen 1105. The catheter shaft 1102 can have
additional lumens for the passage of one or more needles, as
described more fully below.
[0206] Toward the distal end 1104, an optional pair of stabilizers
1112 are fixedly mounted on the outer sheath 1110 at their proximal
end 1114 and fixedly attached to extenders 1116 at their distal end
1118. The stabilizers 1112 are shown in an outwardly bowed
position, however they may be inwardly collapsed by either
extending the extenders 1116 or retracting the outer sheath 1110.
Bowing may be achieved by the reverse process.
[0207] The double-jaw grasper 1113 is comprised of two articulating
jaw arms 1120 which may be opened and closed against the central
shaft 1122 (movement depicted by arrows) either independently or in
tandem. The grasper 1113 is shown in the open position in FIG. 32.
The surfaces of the jaw arms 1120 and central shaft 1122 may be
toothed, as shown, or may have differing surface textures for
varying degrees of friction. The jaw arms 1120 each include a
needle passageway 1121 comprised of a cutout or a slot that extends
at least partially along the length of each jaw arm 1120. As
described in more detail below, the needle passageway provides a
location where a needle can pass through the jaw arm 1120 during
manipulation of the papillary muscle.
[0208] The above described components may be manipulated and
controlled by a handle 1126 connected to the proximal end 1106 of
the catheter shaft 1102, as shown in FIG. 32 the handle 1026
permits independent control of the components described above.
[0209] Referring to FIGS. 33A-C, the device 1100 may be used at
least temporarily grasp and restrain the valve leaflets LF of the
mitral valve MV. The double-jaw grasper 1113 extends through the
valve such that the leaflets LF1, LF2 are grasped from below. Thus,
the device 1100 is termed "atrial-ventricular."
[0210] Referring to FIG. 33A, the atrial device 1100 may be
stabilized against the mitral valve MV. The stabilizers 1112 may be
positioned on the superior surface of the valve leaflets LF1, LF2
at a 90 degree angle to the line of coaptation. The grasper 1113
may be advanced in its closed position from the conduit 1108
between the leaflets LF1, LF2 until the jaw arms 1120 are fully
below the leaflets in the ventricle. At this point, the grasper
1113 may be opened and retracted so that the jaw arms 1120 engage
the inferior surface of the leaflets LF1, LF2. In this manner, the
leaflets are secured between the stabilizers 1112 and the jaw arms
1120.
[0211] Referring to FIG. 33B, the grasper 1113 will gradually
close, drawing the leaflets LF1, LF2 together while maintaining a
secure hold on the leaflets between the jaw arms 1120 and the
stabilizers 1112. This may be accomplished by number of methods.
For example, the stabilizers 1112 may be gradually collapsed by
either extending the extenders 1116 or retracting the outer sheath
1110. As the stabilizers 1112 collapse, the jaw arms 1120 may
collapse due to spring loading to gradually close the grasper 1113.
Alternatively, the jaw arms 1120 may be actuated to close against
the central shaft 1122 applying force to the stabilizers 1112
causing them to collapse. In either case, such action allows the
stabilizers 1112 to simultaneously vertically retract and withdraw
from the leaflets as the leaflets are clamped between the jaw arms
1120 and the central shaft 1122. In this manner, the leaflets are
effectively "transferred" to the grasper 1113. Referring to FIG.
33C, once the collapsed stabilizers 1112 are completely withdrawn,
the leaflets LF1, LF2 are held in vertical opposition by the
grasper 1113 in a more natural coaptation geometry.
[0212] With reference now to FIG. 34, a needle 3410 is advanced
from the left atrium into the left ventricle. The needle 3410 can
be passed through a lumen in the device 1100 or it can be passed
external to the device 1100. In any event, the needle 3410 passes
through a leaflet LF and into a papillary muscle PM. As mentioned,
the jaw arms 1120 have needle passageways 1121 (shown in FIG. 32)
that permit passage of the needle through the jaw arms 1120.
[0213] The needle 3410 is attached to a suture 3415 that extends
distally through the device 1100. The suture 3415 is then anchored
to the papillary muscle PM such that the suture 3415 provides an
attachment for holding, pulling, or otherwise manipulating the
papillary muscle PM. The tension in the suture 3415 can be adjusted
to re-position the papillary muscle PM such that the leaflets LF
contact one another to close the mitral valve. The same process can
be performed with the other papillary muscle.
[0214] With the sutures 3415 holding the papillary muscles PM in a
desired position, as shown in FIG. 35, the chordae CH may be cut.
The sutures 3415 function as artificial chordae that retain the
leaflets LF and papillary muscles PM in a desired orientation.
[0215] A fixation device such as a clip can then be attached to the
leaflets using methods and device described in U.S. Patent
Publication Nos. 2004/0030382, filed Aug. 5, 2003, and
2004/0092962, filed May 19, 2003, U.S. Pat. No. 6,269,819, issued
Aug. 7, 2001, and U.S. Pat. No. 6,461,366, issued Oct. 8, 2002, all
of which are expressly incorporated by reference herein. The
sutures 3415 can be attached to the clip 3510 or directly to the
leaflets LF. It should be appreciated that any quantity of sutures
3415 can be used as artificial chordae between the leaflets and the
papillary muscles. It should be appreciated that the leaflet clips
can also be used in conjunction with cutting, elongating, or
shortening of the chordae pursuant to the methods described
above.
[0216] Prior to permanently placing the chordae or clips, the
result can be previewed on ultrasound (TEE, ICE, echocardiography),
to determine if the appropriate valve coaptation is restored. In
addition, it is within the scope of the present invention to
implant a mitral valve clip in addition to performed papillary
muscle approximation or chordal implantation.
[0217] As will be apparent to those of skill in the art upon
reading this disclosure, each of the individual embodiments
described and illustrated herein has discrete components and
features which may be readily separated from or combined with the
features of any of the other several embodiments without departing
from the scope of the subject matter described herein. Any recited
method can be carried out in the order of events recited or in any
other order which is logically possible.
[0218] Although embodiments of various methods and devices are
described herein in detail with reference to certain versions, it
should be appreciated that other versions, embodiments, methods of
use, and combinations thereof are also possible. Therefore the
spirit and scope of the appended claims should not be limited to
the description of the embodiments contained herein.
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