U.S. patent application number 10/762513 was filed with the patent office on 2004-08-05 for methods and devices for improving mitral valve function.
Invention is credited to Kalgreen, Jason E., Mortier, Todd J., Schroeder, Richard F., Schweich, Cyril J. JR., Vidlund, Robert M..
Application Number | 20040152947 10/762513 |
Document ID | / |
Family ID | 24731098 |
Filed Date | 2004-08-05 |
United States Patent
Application |
20040152947 |
Kind Code |
A1 |
Schroeder, Richard F. ; et
al. |
August 5, 2004 |
Methods and devices for improving mitral valve function
Abstract
The various aspects of the invention pertain to devices and
related methods for treating heart conditions, including, for
example, dilatation, valve incompetencies, including mitral valve
leakage, and other similar heart failure conditions. The devices
and related methods of the present invention operate to assist in
the apposition of heart valve leaflets to improve valve function.
According to one aspect of the invention, a method improves the
function of a valve of a heart by placing an elongate member
transverse a heart chamber so that each end of the elongate member
extends through a wall of the heart, and placing first and second
anchoring members external the chamber. The first and second
anchoring members are attached to first and second ends of the
elongate member to fix the elongate member in a position across the
chamber so as to reposition papillary muscles within the
chamber.
Inventors: |
Schroeder, Richard F.;
(Fridley, MN) ; Vidlund, Robert M.; (Maplewood,
MN) ; Kalgreen, Jason E.; (Plymouth, MN) ;
Schweich, Cyril J. JR.; (St. Paul, MN) ; Mortier,
Todd J.; (Minneapolis, MN) |
Correspondence
Address: |
Susanne T. Jones
FINNEGAN, HENDERSON, FARABOW,
GARRETT & DUNNER, L.L.P
1300 I Street, N.W.
Washington
DC
20005-3315
US
|
Family ID: |
24731098 |
Appl. No.: |
10/762513 |
Filed: |
January 23, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10762513 |
Jan 23, 2004 |
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09680435 |
Oct 6, 2000 |
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6723038 |
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Current U.S.
Class: |
600/37 ;
623/904 |
Current CPC
Class: |
A61F 2/2487 20130101;
A61B 2017/0404 20130101; A61B 2017/048 20130101; A61F 2/2481
20130101; A61B 2017/00243 20130101; A61B 17/00234 20130101; A61B
17/1227 20130101; A61B 2017/0496 20130101 |
Class at
Publication: |
600/037 ;
623/904 |
International
Class: |
A61F 002/02 |
Claims
What is claimed is:
1. A method for improving the function of a valve of a heart, the
method comprising the steps of: placing an elongate member
transverse a heart chamber so that a first end of the elongate
member extends through a wall of the heart between two papillary
muscles, and a second end of the elongate member extends through a
septum of the heart; placing a first anchoring member external the
heart; and placing a second anchoring member inside the heart
adjacent the septum, the first and second anchoring members being
attached to the first and second ends of the elongate member
respectively to fix the elongate member in a position across the
heart chamber.
2. The method of claim 1, wherein the heart chamber is the left
ventricle and the valve is the mitral valve.
3. The method of claim 2, wherein the first end of the elongate
member extends through a wall of the heart approximately midway
between the antero lateral papillary muscle and the posterio medial
papillary muscle.
4. The method of claim 3, wherein the elongate member is placed
proximate the mitral valve.
5. The method of claim 1, wherein the elongate member is fixed in
the position so as to change a shape of the heart chamber.
6. The method of claim 1, wherein the elongate member is fixed in
the position so as to reposition the papillary muscles.
7. A method for improving the function of a valve of a heart, the
method comprising the steps of: placing a first elongate member
transverse a heart chamber so that each end of the first elongate
member extends through a wall of the heart; placing first and
second anchoring members external the chamber, the first and second
anchoring members being attached to the ends of the first elongate
member to fix the first elongate member in a first position across
the chamber; placing a second elongate member transverse the heart
chamber so that each end of the second elongate member extends
through a wall of the heart; placing third and fourth anchoring
members external the chamber, the third and fourth anchoring
members being attached to the ends of the second elongate member to
fix the second elongate member in a second position across the
chamber, wherein the first and second positions are substantially
coplanar and have differing angles relative to an axis of the
chamber.
8. The method of claim 7, wherein the heart chamber is the left
ventricle and the valve is the mitral valve.
9. The method of claim 7, wherein the first and second elongate
members are fixed in the first and second positions so as to change
a shape of the heart chamber.
10. The method of claim 7, wherein the first and second elongate
members are fixed in the first and second positions so as to
reposition papillary muscles within the chamber.
11. A method for improving the function of a valve of a heart, the
method comprising the steps of: placing an elongate member
transverse a heart chamber so that each end of the elongate member
extends through a wall of the heart; and placing first and second
anchoring members external the chamber, the first and second
anchoring members being attached to the ends of the elongate member
to fix the elongate member in a position across the chamber,
wherein the position is superior to the papillary muscles and
proximate and substantially across the valve.
12. The method of claim 11, wherein the heart chamber is the left
ventricle and the valve is the mitral valve.
13. The method of claim 11, wherein the position of the elongate
member alters a shape of an annulus of the valve.
14. The method of claim 11, wherein the position of the elongate
member repositions the papillary muscles within the chamber.
15. A splint for improving the function of a valve of a heart, the
splint comprising: an elongate member configured to be positioned
transverse a heart chamber so that each end of the elongate member
extends through a wall of the heart; and first and second anchoring
members configured to be positioned external the chamber and
attached to the ends of the elongate member to fix the elongate
member in a position across the chamber, wherein the first
anchoring member includes a first portion configured to contact a
first region of the heart proximate the valve to change a shape of
the valve.
16. The splint of claim 15, wherein the heart chamber is the left
ventricle and the valve is the mitral valve.
17. The splint of claim 16, wherein the first region of the heart
is a superior portion of the left ventricle proximate an annulus of
the mitral valve.
18. The splint of claim 16, wherein the first region of the heart
is a portion of the left atrium proximate an annulus of the mitral
valve.
19. The splint of claim 15, wherein the first portion has an oblong
shape.
20. The splint of claim 15, wherein the first anchoring member
further includes a second portion configured to contact a second
region of the heart below the first region.
21. The splint of claim 20, wherein the second portion includes a
first structure connected to the elongate member and a second
structure connected to the first portion by the first
structure.
22. A splint for improving the function of a valve of a heart, the
splint comprising: an elongate member configured to be positioned
transverse a heart chamber so that each end of the elongate member
extends through a wall of the heart; first and second anchoring
members configured to be positioned external the chamber and
attached to the ends of the elongate member to fix the elongate
member in a position across the chamber; and a third anchoring
member connected to at least one of the first and second anchoring
members by a connection member, the third anchoring member
configured to contact a region of the heart proximate the valve to
change a shape of the valve.
23. The splint of claim 22, wherein the third anchoring member
connects to the first and second anchoring members by the
connection member.
24. The splint of claim 22, wherein the third anchoring member
includes a connection mechanism for connecting the third anchoring
member to the connection member.
25. The splint of claim 24, wherein the connection mechanism
includes a locking screw.
26. The splint of claim 24, wherein the connection mechanism
includes a pin.
27. The splint of claim 22, further comprising a connection
mechanism for connecting the connection member to the at least one
of the first and second anchoring members.
28. The splint of claim 27, wherein the connection mechanism
includes a locking screw.
29. The splint of claim 27, wherein the connection mechanism
includes a pin.
30. The splint of claim 27, wherein the connection mechanism
includes a cap configured to fit over the at least one of the first
and second anchoring members.
31. The splint of claim 23, further comprising an adjustment
mechanism for adjusting a length of the connection member between
the first and second anchoring members.
32. A device for improving the function of a valve of a heart, the
device comprising: a first splint having a first elongate member
configured to be positioned transverse a heart chamber so that each
end of the elongate member extends through a wall of the heart, and
a first anchoring member configured to be positioned external the
chamber and attached to a first end of the first elongate member; a
second splint having a second elongate member configured to be
positioned transverse a heart chamber so that each end of the
second elongate member extends through a wall of the heart, and a
second anchoring member configured to be positioned external the
chamber and attached to a first end of the second elongate member;
and a connecting mechanism configured to be connected to the second
ends of each of the first and second elongate members external the
chamber and press the wall of the heart chamber to change the shape
of an annulus of the valve.
33. The device of claim 32, wherein the connection mechanism is a
bar.
34. The device of claim 32, wherein the heart chamber is the left
ventricle and the valve is the mitral valve.
35. The device of claim 32, wherein the device is configured so
that the connecting bar presses the wall of the heart chamber to
change the shape of chamber.
36. A method for improving the function of a valve of a heart, the
method comprising the steps of: placing an elongate member
transverse a heart chamber so that each end of the elongate member
extends through a wall of the heart; and placing first and second
anchoring members external the chamber, the first and second
anchoring members being attached to first and second ends of the
elongate member to fix the elongate member in a position across the
chamber so as to reposition papillary muscles within the
chamber.
37. The method of claim 36, wherein the first end of the elongate
member extends through a wall of the left ventricle between
papillary muscles.
38. The method of claim 37, wherein the second end of the elongate
member extends through a septum of the heart.
39. The method of claim 36, wherein the chamber is the left
ventricle and the valve is the mitral valve.
40. The method of claim 36, wherein the position is superior to the
papillary muscles and proximate and substantially across the
valve.
41. The method of claim 36, wherein the elongate member is fixed in
the position so as to alter the shape of an annulus of the
valve.
42. A method for improving cardiac function, comprising: placing a
first member relative to a heart chamber to alter the
cross-sectional shape of the chamber; and placing a second member
relative to a valve of the heart chamber to assist in apposition of
leaflets of the valve.
43. The method of claim 42, wherein each of the first and second
members includes a portion placed transverse the chamber.
44. The method of claim 42, wherein each of the first and second
members includes an elongate member.
45. The method of claim 44, wherein the placing each of the first
and second elongate members includes securing the elongate members
relative to the heart chamber with anchors configured to engage
each end of the elongate members and configured to engage an
exterior surface of a wall surrounding the hears chamber.
46. The method of claim 45, wherein the securing the second
elongate member includes engaging one of the anchors with an
exterior surface of the heart wall proximate the valve to alter a
shape of an annulus of the valve.
47. The method of claim 42, wherein the heart chamber is a left
ventricle.
48. The method of claim 42, wherein the valve is a mitral
valve.
49. The method of claim 42, wherein the placing the second member
includes altering the cross-sectional shape of an annulus of the
valve.
50. The method of claim 42, wherein the placing the second member
includes reducing a radius of an annulus of the valve.
51. The method of claim 42, wherein the placing the second member
includes placing the second member so as to alter a position of at
least one papillary muscle of the heart chamber.
52. The method of claim 51, wherein the placing the second member
includes securing the second member with respect to the heart
chamber with an anchor configured to engage an exterior surface of
a wall surrounding the heart chamber substantially at a location of
the at least one papillary muscle.
53. The method of claim 42, wherein the placing the first member
includes placing an elongate member transverse the heart chamber
and through a wall surrounding the heart chamber at substantially
opposite locations on the heart wall.
54. A method of improving the function of a valve of a heart, the
method comprising: applying a force to an exterior surface of a
wall surrounding a chamber of the heart substantially at a location
of the valve to alter a shape of the valve.
55. The method of claim 54, wherein applying the force alters the
shape of an annulus of the valve.
56. The method of claim 54, wherein altering the shape of the valve
includes appositioning leaflets of the valve.
57. The method of claim 54, wherein altering the shape of the valve
includes reducing a radius of an annulus of the valve.
58. The method of claim 54, wherein the force is applied by a
device having an elongate member placed transverse the chamber and
a first anchor assembly connected at a first end of the member
external the chamber and a second anchor assembly connected at a
second end of the member external the chamber.
59. A method for improving the function of a valve of a heart,
comprising: placing a device relative to the heart to alter a shape
of the valve; and adjusting the device relative to the heart based
on data obtained during the adjusting from real-time monitoring of
valve function.
60. The method of claim 59, wherein the device is a splint.
61. The method of claim 59, wherein the device is a splint and
adjusting the splint includes changing a distance between at least
two portions of the splint that contact respective portions of the
heart.
62. The method of claim 59, wherein the real-time monitoring
includes imaging the valve.
63. The method of claim 62, wherein the imaging of the valve
includes ultrasound imaging.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to devices and related methods
for improving the function of heart valves, and more particularly
to devices and related methods that passively assist in the
apposition of heart valve leaflets to improve valve function of
poorly functioning valves.
[0003] 2. Description of the Related Art
[0004] Heart failure is a condition whereby the left ventricle
becomes enlarged and dilated as a result of numerous etiologies.
Initial causes of heart failure include chronic hypertension,
myocardial infarction, mitral valve incompetency, and other dilated
cardiomyopathies. With each of these conditions, the heart is
forced to overexert itself in order to provide the cardiac output
demanded from the body during its various demand states. The result
is an enlarged left ventricle.
[0005] A dilated heart, and particularly a dilated left ventricle,
can significantly increase the tension and/or stress in the heart
wall both during diastolic filling and systolic contraction, which
contributes to ongoing dilatation of the chamber. Prior treatments
for heart failure include pharmacological treatments, assist
devices such as pumps, and surgical treatments such as heart
transplant, dynamic cardiomyoplasty, and the Batista partial left
ventriculectomy. These prior treatments are described briefly in
U.S. Pat. No. 5,961,440 to Schweich, Jr. et al., issued Oct. 5,
1999 and entitled "Heart Wall Tension Reduction Apparatus and
Method," the complete disclosure of which is incorporated by
reference herein.
[0006] A more recent concept for treating heart failure applies one
or more splints onto the heart, and particulary the left ventricle,
to reduce the myocardial muscular stresses encountered during
pumping. Many examples of such approaches are disclosed in the
incorporated U.S. Pat. No. 5,961,440. One example includes one or
more transventricular splints placed across the left ventricle.
Each splint may include a tension member extending across the
ventricle and anchors disposed on opposite ends of the tension
member and placed on the external surface of the heart.
[0007] Mitral valve incompetency or mitral valve regurgitation is a
common comorbidity of, congestive heart failure. As the dilation of
the ventricle proceeds, valve function may worsen. The resultant
volume overload condition, in turn, increases ventricular wall
stress thereby advancing the dilation process, which may further
worsen valve dysfunction.
[0008] In heart failure, the size of the valve annulus
(particularly the mitral valve annulus) increases while the area of
the leaflets of the valve remains constant. This may lead to an
area of less coaptation of the valve leaflets, and, as a result,
eventually to valve leakage. Moreover, in normal hearts, the
annular size contracts during systole, aiding in valve coaptation.
In heart failure, there is poor ventricular function and elevated
wall stress. These effects tend to reduce annular contraction and
distort annular size, often exacerbating mitral valve
regurgitation. In addition, as the chamber dilates, the papillary
muscles (to which the leaflets are connected via the chordae
tendonae) may move radially outward and downward relative to the
valve, and relative to their normal positions. During this movement
of the papillary muscles, however, the various chordae lengths
remain substantially constant, which limits the full closure
ability of the leaflets by exerting tension prematurely on the
leaflets. This condition is commonly referred to as "chordal
tethering." The combination of annular changes and papillary
changes results in a poorly functioning valve.
[0009] It has been observed that for at least certain placements,
or orientations, of the one or more transventricular splints in
humans, a pre-existing mitral valve incompetency can be exacerbated
by the presence and impact of the tightened splints. The splints
and the local deformation they impart may further alter the
positions of the papillary muscles in such a way that the chordae
do not allow as complete of a closure of the mitral valve, or that
rotation of portions of the ventricular wall (to which additional
chordae may be attached) may "tighten" one valve leaflet and
"loosen" the other. In this manner, the leaflets may not close at
the same level relative to the annulus, causing increased
retrograde leakage through the valve.
[0010] Even in instances where the placement of splints does not
contribute to further mitral valve leakage, it may be desirable to
provide a therapy which could also correct the valve incompetency.
A heart with even a small amount of regurgitation may benefit from
not only the stress reducing functions of the ventricular splints
as described above, but also from the elimination of the
regurgitation, which will further off-load the pumping requirements
of the myocardium.
[0011] While currently available methods of mitral valve repair or
replacement are possible to employ in conjunction with ventricular
splinting, they typically require opening the heart to gain direct
access to the valve and its annulus. This type of access
necessitates the use of cardiopulmonary bypass, which can introduce
additional complications to the surgical procedure. Since the
implantation of the splints themselves do not require the patient
to be on cardiopulmonary bypass, it would be advantageous to devise
a technique which could improve the mitral valve without the need
for cardiopulmonary bypass. The ability to improve the mitral valve
function without the need for cardiopulmonary bypass would be an,
advantage, both in conjunction with ventricular splinting, and also
as a stand-alone therapy.
SUMMARY OF THE INVENTION
[0012] Objects and advantages of the invention will be set forth in
part in the description which follows, and in part will be obvious
from the description, or may be learned by practice of the
invention. The objects and advantages of the invention will be
realized and attained by means of the elements and combinations
particularly pointed out in the appended claims. To achieve the
objects and in accordance with the purpose of the invention, as
embodied and broadly described herein, one aspect of the invention
comprises a method for improving the function of a valve of a
heart. The method includes the steps of placing an elongate member
transverse a heart chamber so that each end of the elongate member
extends through a wall of the heart, and placing first and second
anchoring members external to the chamber. The first and second
anchoring members are attached to first and second ends of the
elongate member to fix the elongate member in a position across the
chamber so as to reposition papillary muscles within the
chamber.
[0013] According to another aspect, the invention comprises a
method for improving the function of a valve of a heart. The method
includes the steps of placing an elongate member transverse a heart
chamber so that a first end of the elongate member extends through
a wall of the heart between two papillary muscles, and a second end
of the elongate member extends through a septum of the heart;
placing a first anchoring member external the heart; and placing a
second anchoring member inside the heart adjacent the septum. The
first and second anchoring members are attached to the first and
second ends of the elongate member respectively to fix the elongate
member in a position across the heart chamber.
[0014] According to a further aspect, the invention comprises a
method for improving the function of a valve of a heart. The method
includes the steps of placing an elongate member transverse a heart
chamber so that each end of the elongate member extends through a
wall of the heart; and placing first and second anchoring members
external the chamber. The first and second anchoring members are
attached to the ends of the elongate member to fix the elongate
member in a position across the chamber. The position is superior
to the papillary muscles and proximate and substantially across the
valve.
[0015] According to an even further aspect, the invention comprises
a splint for improving the function of a valve of a heart. The
splint includes an elongate member configured to be positioned
transverse a heart chamber so that each end of the elongate member
extends through a wall of the heart, and first and second anchoring
members configured to be positioned external the chamber and
attached to the ends of the elongate member to fix the elongate
member in a position across the chamber. The first anchoring member
includes a first portion configured to contact a first region of
the heart proximate the valve to change a shape of the valve.
Preferably, the first portion will contact a first region of the
heart proximate the valve annulus to change the shape of the valve
annulus.
[0016] According to another aspect, the invention comprises a
splint for improving the function of a valve of a heart. The splint
includes an elongate member configured to be positioned transverse
a heart chamber so that each end of the elongate member extends
through a wall of the heart, first and second anchoring members
configured to be positioned external the chamber and attached to
the ends of the elongate member to fix the elongate member in a
position across the chamber, a third anchoring member connected to
at least one of the first and second anchoring members by a
connection member. The third anchoring member is configured to
contact a region of the heart proximate the valve to change a shape
of the valve.
[0017] According to a further aspect, the invention comprises a
device for improving the function of a valve of a heart. The device
includes a first splint having a first elongate member configured
to be positioned transverse a heart chamber so that each end of the
elongate member extends through a wall of the heart, and a first
anchoring member configured to be positioned external the chamber
and attached to a first end of the first elongate member. The
device further includes a second splint having a second elongate
member configured to be positioned transverse a heart chamber so
that each end of the second elongate member extends through a wall
of the heart, and a second anchoring member configured to be
positioned external the chamber and attached to a first end of the
second elongate member. The device also includes a connecting
mechanism configured to be connected to the second ends of each of
the first and second elongate members external the chamber and
press the wall of the heart chamber to change a shape of the
valve.
[0018] Yet a further aspect of the invention includes a method for
improving cardiac function, comprising placing a first member
relative to a heart chamber to alter the cross-sectional shape of
the chamber and placing a second member relative to a valve of the
heart chamber to assist in apposition of leaflets of the valve.
[0019] According to an even further aspect, the invention includes
a method of improving the function of a valve of a heart comprising
applying a force to an exterior surface of a wall surrounding a
chamber of the heart substantially at a location of the valve to
alter a shape of the valve.
[0020] Yet a further aspect of the invention includes a method for
improving the function of a valve of a heart comprising placing a
device relative to the heart to alter a shape of the valve and
adjusting the device relative to the heart based on data obtained
during the adjusting from real-time monitoring of valve
function.
[0021] It is to be understood that both the foregoing general
description and the following detailed description are exemplary
and explanatory only and are not restrictive of the invention, as
claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The accompanying drawings, which are incorporated in and
constitute a part of this specification, illustrate several
embodiments of the invention and together with the description,
serve to explain the principles of the invention.
[0023] FIG. 1 is a transverse cross section of the left and right
ventricles of a human heart showing the placement of splints
according to an orientation for lessening myocardial muscular
stresses;
[0024] FIG. 2a is a transverse cross section of the left and right
ventricles of a human heart showing the orientation of splints
according to an embodiment of the present invention for lessening
myocardial muscular stresses and assisting in apposition of valve
leaflets;
[0025] FIG. 2b is a vertical cross section of the left and right
ventricles of a human heart showing another orientation of
ventricular shape change splints according to an embodiment of the
present invention for lessening myocardial muscular stresses and
assisting in apposition of valve leaflets;
[0026] FIG. 3a is a transverse cross section of the left and right
ventricles of a human heart showing an orientation of a mitral
valve splint used in combination with a series of transventricular
splints according to an embodiment of the present invention for
lessening myocardial muscular stresses and assisting in apposition
of valve leaflets;
[0027] FIG. 3b is an external view of a human heart showing the
orientation of the mitral valve splint and series of
transventricular splints of FIG. 3a;
[0028] FIG. 3c is a transverse cross section of the left and right
ventricle of a human heart showing a various orientations for a
mitral valve splint used in combination with a series of
transventricular splints according to an embodiment of the present
invention;
[0029] FIG. 4a is an external view of a human heart showing a
series of transventricular splints, with the superior-most splint
having an anchor structure according to an embodiment of the
present invention that assists in apposition of valve leaflets;
[0030] FIG. 4b is an external view of a human heart showing a
series of transventricular splints, with the superior most splint
having an anchor structure and a connection mechanism between the
superior most and middle anchors according to yet another
embodiment of the present invention that assists in apposition of
valve leaflets;
[0031] FIG. 4c is a perspective view of an anchor assembly for a
transventricular splint according to yet another embodiment of the
present invention that assists in apposition of valve leaflets and
repositioning of papillary muscles;
[0032] FIG. 5a is a transverse cross section of the left and right
ventricles of a human heart showing the placement of splints
according to an orientation for lessening myocardial muscular
stresses with an accessory anchor assembly according to an
embodiment of the present invention to assist in apposition of
valve leaflets;
[0033] FIG. 5b is a transverse cross section of the left and right
ventricles of a human heart showing the placement of splints
according to an orientation for lessening myocardial muscular
stresses with an accessory anchor assembly according to another
embodiment of the present invention to assist in apposition of
valve leaflets;
[0034] FIG. 6 is a transverse cross section of the left and right
ventricles of a human heart showing an orientation of a mitral
valve splint used in combination with a series of transventricular
splints, with an interconnecting mechanism according to an
embodiment of the present invention for lessening myocardial
muscular stresses and assisting in apposition of valve leaflets;
and
[0035] FIG. 7 is a perspective view of a heart with an external
splint device and mitral valve anchor assembly and connecting
mechanism disposed relative to the left ventricle to alter the
shape of the left ventricle and to assist in apposition of valve
leaflets according to an embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0036] The various aspects of the invention to be discussed herein
generally pertain to devices and methods for treating heart
conditions, including, for example, dilatation, valve
incompetencies, including mitral valve leakage, and other similar
heart failure conditions. Each device of the present invention
preferably operates passively in that, once placed in the heart, it
does not require an active stimulus, either mechanical, electrical,
or otherwise, to function. Implanting one or more of the devices of
the present invention operates to assist in the apposition of heart
valve leaflets to improve valve function. In addition, these
devices may either be placed in conjunction with other devices
that, or may themselves function to alter the shape or geometry of
the heart, locally and/or globally, and thereby further increase
the heart's efficiency. That is, the heart experiences an increased
pumping efficiency through an alteration in its shape or geometry
and concomitant reduction in stress on the heart walls, and through
an improvement in valve function.
[0037] The inventive devices and related methods offer numerous
advantages over the existing treatments for various heart
conditions, including valve incompetencies. The devices are
relatively easy to manufacture and use, and the surgical techniques
and tools for implanting the devices of the present invention do
not require the invasive procedures of current surgical techniques.
For instance, the surgical technique does not require removing
portions of the heart tissue, nor does it necessarily require
opening the heart chamber or stopping the heart during operation.
For these reasons, the surgical techniques for implanting the
devices of the present invention also are less risky to the patient
than other techniques. The less invasive nature of the surgical
techniques and tools of the present invention may also allow for
earlier intervention in patients with heart failure and/or valve
incompetencies.
[0038] The disclosed inventive devices and related methods involve
geometric reshaping of the heart and treating valve incompetencies.
In certain aspects of the inventive devices and related methods,
substantially the entire chamber geometry is altered to return the
heart to a more normal state of stress. Models of this geometric
reshaping, which includes a reduction in radius of curvature of the
chamber walls, can be found in U.S. Pat. No. 5,961,440 incorporated
above. Prior to reshaping the chamber geometry, the heart walls
experience high stress due to a combination of both the relatively
large increased diameter of the chamber and the thinning of the
chamber wall. Filling pressures and systolic pressures are
typically high as well, further increasing wall stress. Geometric
reshaping according to the present invention reduces the stress in
the walls of the heart chamber to increase the heart's pumping
efficiency, as well as to stop further dilatation of the heart.
[0039] Although many of the methods and devices are discussed below
in connection with their use in the left ventricle and for the
mitral valve of the heart, these methods and devices may be used in
other chambers and for other valves of the heart for similar
purposes. One of ordinary skill in the art would understand that
the use of the devices and methods described herein also could be
employed in other chambers and for other valves of the heart. The
left ventricle and the mitral valve have been selected for
illustrative purposes because a large number of the disorders that
the present invention treats occur in the left ventricle and in
connection with the, mitral valve. Furthermore, the devices
disclosed herein for improving valve function can be "stand-alone"
devices, that is, they do not necessarily have to be used in
conjunction with devices for changing the shape of a heart chamber
or otherwise reducing heart wall stress. It also is contemplated
that a device for improving valve function may be placed relative
to the heart without altering the shape of the chamber, and only
altering the shape of the valve itself.
[0040] Reference will now be made in detail to the present
preferred embodiments of the invention, examples of which are
illustrated in the accompanying drawings. Wherever possible, the
same reference numbers will be used throughout the drawings to
refer to the same or like parts.
[0041] A currently preferred orientation of transventricular
splints for lessening myocardial muscular stresses is shown in FIG.
1, which shows the short-axis left ventricular cross-section from
an anterior perspective. Examples of particular transventricular
splints that are especially suitable for this application include
those shown and described in copending U.S. patent application Ser.
No. 09/532,049 to Vidlund et al., filed Mar. 21, 2000, entitled "A
Splint Assembly for Improving Cardiac Function in Hearts, and
Method for Implanting the Splint Assembly," and comunonly assigned
to the assignee of the present invention. The complete discosure of
that application is incorporated by reference herein. That
application will be referred to as "the '049 application" in the
remainder of this disclosure.
[0042] In the preferred orienation shown in FIG. 1, three splints
are placed in a coplanar fashion, along the long axis of the
ventricle, bisecting the left ventricle LV of the heart 10. FIG. 1
is a cross-section (short axis) view looking from the superior side
of the heart. The superior-most splint 14 is placed at
approximately the level of the heads of the papillary muscles PM
and below the level of leaflet coaptation, and the additional two
splints (not shown in FIG. 1) are placed inferiorly toward the
apex. The preferred orientation shown in FIG. 1 both bisects the
left ventricle LV and avoids key structures such as coronary
vessels and the like. The splints according to this orientation
also extend through the septum S near its edge and enter a small
portion of the right ventricle RV.
[0043] Each splint includes a tension member 16 and an anchor
assembly 18 at each end of the tension member 16. Presently
preferred embodiments of tension members 16, anchor assemblies 18,
and their connection to one another are disclosed in the '049
application incorporated by reference above. As shown in FIG. 1,
tension member 16 extends through the the heart wall HW, across the
left ventricle LV, and through the septum S and a portion of the
right ventricle RV. Anchor assemblies 18 are placed adjacent the
external surface of the heart wall HW.
[0044] As mentioned above, human implantations of splints,
including in an orientation shown in FIG. 1, may exacerbate any
pre-existing mitral valve incompetency, including mitral valve
regurgitation (MVR), or at the least, may not improve any
pre-existing MVR. FIG. 2a shows an orientation of splints 14
according to an embodiment of the present invention which may
assist in both offloading myocardial wall stress and in aiding the
apposition of valve leaflets. According to this orientation, each
tension member 16 of splint 14 extends through the heart wall HW at
a position approximately midway between the antero lateral
papillary muscle PM and the posterio medial papillary muscle PM,
extends transverse the left ventricle LV, and extends through the
septum S at approximately its midpoint. A first anchor assembly 18
is placed external the heart 10 adjacent the heart wall HW and a
second anchor assembly is placed inside the right ventricle RV
adjacent septum S. FIG. 2a shows the superior-most splint 14 of
preferably three splints, with the other two splints placed
inferiorly towards the apex. More or less than three splints may be
used. The splints in this orientation are generally parallel to one
another and substantially perpendicular to the long axis of the
left ventricle.
[0045] The orientation of splints 14 shown in FIG. 2a helps to
"pull" both of the papillary muscles PM toward the center of the
left ventricle LV and reposition those muscles closer to their
normal physiological position relative to the mitral valve annulus
during the complete cardiac cycle. During the course of heart
failure dilation, the papillary muscles PM are moved laterally away
from their normal position, which causes the chordae connected to
both valve leaflets to become excessively taut. This in turn
inhibits the leaflets from fully closing against each other. By
bringing the papillary muscles PM closer to the center of the
ventricle LV, the chordae are slackened enough to allow the
leaflets to appose, thereby improving on mitral valve function.
Additionally, although the splints 14 in this approach are
preferably positioned at and below the level of the tops of the
papillary muscles PM, the shape change deformation at the
superior-most splint 14 would extend in a region further superior,
and potentially include the annulus itself. To the extent that the
annulus in the region of the posterior leaflet is deformed, this
would further benefit the valve function by reducing the
cross-sectional area of the annulus and positioning the posterior
leaflet and its attachment zone closer to the anterior annulus.
This, in turn, will cause the leaflets to more fully appose,
minimizing MVR.
[0046] Various methods may be employed to implant the splints 14 in
the orientaion shown in FIG. 2a. One particularly advantageous
method is an endovascular delivery technique shown and described in
co-pending U.S. patent application Ser. No. ______, to Robert M.
Vidlund et al., entitled "Endovascular Splinting Devices and
Methods," filed on the same day as this application and commonly
assigned to the assignee of this application, the entire i
disclosure of which is incorporated by reference herein. Splints 14
also may be positioned in the orientation shown in FIG. 2a by other
surgical techniques, such as those described in the '049
application incorporated by reference above. For example, to gain
access to the ventricular septum S, a small incision can be placed
within the right ventricular wall to allow for positioning tension
member 16 and the anchor assembly 18 within the right ventricle RV.
The methods of implantation shown and described in the applications
referred to above may be used in connection with any of the
embodiments shown and described herein.
[0047] FIG. 2b shows another orientation of splints 14 according to
an embodiment of the present invention which may assist in the
offloading of myocardial wall stress and in the apposition of valve
leaflets. According to this orientation, at least one splint 14 is
angled with respect to the long axis of the left ventricle LV, in
contrast to orienting the at least one splint 14 perpendicular to
the axis of the left ventricle LV. In the embodiment shown in FIG.
2b, the lower two splints 14 are angled relative to the ventricular
axis and relative to the superior-most splint 14, which is
approximately perpendicular to the ventricular axis. In this
example, all three splints 14 are coplanar, as is preferred for
optimizing the ventricular shape change. While FIG. 2b illustrates
the ventricular splints having an anchor pad disposed on the
septum, it is contemplated that the benefits of angling one or more
splints relative to the long axis of the ventricle could be
achieved at other cross-sectional orientations including, for
example, the orientation shown in FIG. 1, in which an anchor pad is
located on an exterior wall of the heart as opposed to the septum
wall.
[0048] Because the lower two splints 14 are positioned at an angle,
they tend to "lift" one or both papillary muscles PM as they impart
shape change to the left ventricle LV. By lifting the papillary
muscle(s) PM, some slack may be provided to the chordae connected
to the valve leaflets to permit improved apposition of the leaflets
of mitral valve MV. It is contemplated that more or less splints
than the lower two splints may be angled (other than
perpendicularly) relative to the ventricular axis to achieve the
benefits to MVR, and that each splint may have a different angle
relative to that axis. For example, all three splints could be
angled, or only one splint could be angled. The number of splints
to be angled, and the degree of such angles, would be chosen to
optimize the improvement in MVR and would depend on factors such as
the particular anatomy of a heart. The splint positioning can be
iteratively changed and the impact on MVR, and mitral valve
function in general, can be monitored using appropriate "real-time"
imaging techniques and equipment, such as, for example, ultrasound
and other suitable mechanisms. The ventricular splints 14 shown in
FIG. 2b may be oriented in any suitable cross sectional position,
including the positions shown in FIG. 1 or 2a. The benefits to MVR
of angularly positioning one or more of the ventricular splints 14
relative to the ventricular axis, as shown in FIG. 2b, may be
achieved independent of the particular cross sectional position of
the splints 14.
[0049] According to an embodiment of the present invention, a
method of improving mitral valve function, while maintaining the
positions and orientations of the ventricular splints shown in FIG.
1, includes the use of an additional splint. This additional
splint, referred to herein as a mitral valve splint or MV splint,
preferably has the same construction as the other splints and may
be implanted using the similar delivery techniques. The primary
function of the MV splint is to impart a shape change to the mitral
valve annulus, adjacent the left ventricular wall, as well as
reposition the papillary muscles PM.
[0050] FIGS. 3a and 3b show an MV splint according to an embodiment
of the present invention. FIGS. 3a and 3b show the three
ventricular splints 14 in the positions and orientations shown and
described in connection with FIG. 1 (the dashed lines in FIGS. 3a,
3b) and show an exemplary orientation of an MV splint 20. It should
be noted that in FIGS. 3a and 3b the shape change to the left
ventricle caused by the transventricular splints 14 is not
illustrated. MV splint 20 is positioned superior to the papillary
muscles PM and oriented primarily across the mitral valve MV and on
or below the mitral valve annulus while avoiding key vascular
structures. In this orientation, MV splint 20 is "out of plane"
with the other ventricular splints 14, as the overall function of
MV splint 20 is to improve and optimize the mitral valve function.
In the example shown in FIGS. 3a and 3b, the MV splint extends
through the heart wall between the papillary muscles of the left
ventricle LV, and extends transverse the left ventricle LV, through
the septum S, through the right ventricle RV, and once again
through the heart wall.
[0051] The MV splint 20 improves mitral valve function through a
combination of effects. First, the shape of the annulus is directly
altered, preferably during the entire cardiac cycle, thereby
reducing the annular cross sectional area and bringing the
posterior leaflet in closer apposition to the anterior leaflet.
Second, the position and rotational configuration of the papillary
muscles PM and surrounding areas of the left ventricle LV are
further altered by the tightening of the MV splint 20. This places
the chordae in a more favorable state of tension, allowing the
leaflets to more fully appose each other. Third, since the annulus
of the valve is muscular and actively contracts during systole,
changing the shape of the annulus will also reduce the radius of
curvature of at least portions of the annulus, just as the shape
change induced by the ventricular splints reduces the radius of at
least significant portions of the ventricle. This shape change and
radius reduction of the annulus causes off-loading of some of the
wall stress on the annulus. This, in turn, assists the annulus's
ability to contract to a smaller size, thereby facilitating full
closure of the mitral valve MV during systole.
[0052] The position of the MV splint 20 shown in FIGS. 3a and 3b is
exemplary. The ventricular splints 14 preferably are positioned
prior to positioning MV splint 20, through the use of, for example,
both angiographic and ultrasonic visualization tools. This
positioning technique, described in the '049 application
incorporated above, achieves optimal positioning of splints 14 to
bisect the left ventricle LV and avoid key anatomic structures.
After positioning the ventricular splints 14, a device such as the
probe/marking device shown and described in the '049 application
may be used to repeatedly probe and deform possible areas near the
mitral valve to find the optimal position for the MV splint 20., By
utilizing, for example, standard "real-time" ultrasonic imaging
techniques, the direct impact of the probing on MVR can be
assessed, and pre-existing MVR or MVR exacerbated by placement of
the ventricular splints 14 can be corrected. Once the optimal
position for an MV splint 20 is determined and marked, the MV
splint 20 is implanted and positioned by any of the delivery
techniques referred to above, including the endovascular delivery
technique or the more direct surgical approaches. The use of the MV
splint 20 allows for the optimal placement of the ventricular
splints 14, which reduce heart wall stress, independent from the
optimal subsequent positioning of the MV splint 20, which improves
mitral valve function. During implantation, the splint can be
adjusted (either in position or in tightness or both) to optimize
improvement to valve function, as determined by observation of the
valve using real-time imaging techniques.
[0053] It is anticipated that the optimal position of the MV splint
20 could be at virtually any orientation relative to the valve
leaflets, depending on the heart failure and mitral valve
regurgitation associated with the particular heart at issue. For
example, in some hearts, the position shown and described in
connection with FIGS. 3a and 3b may yield the most improvement of
MVR, whereas in other hearts, alternative positions such as shown
in FIG. 3c may yield the most improved results. Note that in FIG.
3c, the transventricular splint is shown positioned between the
papillary muscles, which may be another preferred orientation for
certain hearts. Alternative "A" places MV splint to cause shape
change between the papillary muscles Alternative "B" for MV splint
positioning would be in a line more parallel to the valve leaflet
edges, as shown in FIG. 3d. Other placements of the MV splint, as
well as the position of the transventricular splints, relative to
the heart also are contemplated and could be selected based on the
condition of the heart and the mitral valve.
[0054] According to another embodiment of the present invention, an
alternative anchor assembly for the ventricular splints 14 may be
provided to aid in mitral valve function. In the embodiment shown
in FIG. 4a, the superior-most splint 14 includes an anchor assembly
28 configured for connection to the "free wall" end of that splint
14, i.e., at the exterior wall of the left ventricle. Anchor
assembly 28 includes a lower portion in the form of, for example, a
lower pad portion 30 which contacts the external surface of the
left ventricle wall somewhat below the level of the tension member
16. In a preferred embodiment, the lower pad portion 30 resembles
the shape, size, and construction of the anchor pads described in
the '049 application incorporated above. Anchor assembly 28 further
includes an upper portion in the form of, for example, an upper pad
portion 34 which contacts a superior region of the left ventricle
wall near the mitral valve annulus. Tension member 16 connects to a
spanning structure 32 that, in one embodiment, is preferably
integrally fabricated with the lower and upper pad portions 30 and
34, and connects portions 30 and 34. Suitable materials for anchor
assembly may include, but are not limited to, those described in
the '049 application. At least the lower and upper pad portions 30
and 34 preferably include a covering or a coating of a material,
such as, for example, a woven polyester fabric, to encourage tissue
in-growth. The spanning structure 32 also may be made of, or
include a covering or coating made of, a material to encourage
tissue in-growth
[0055] In the exemplary, preferred embodiment shown in FIG. 4a, the
lower pad portion 30 has a circular shape and the upper pad portion
34 has an oblong shape. The oblong shape of the upper pad portion
34 has the advantage of inducing relatively extensive shape change
along the periphery of the valve annulus, preferably during the
entire cardiac cycle. Therefore, in an embodiment, the length and
shape of the upper pad portion may extend a significant distance
around the valve annulus. For example, the upper pad portion 34 may
extend from about 1 cm in length to about 10 cm in length,
depending on the desired shape change of the valve annulus. The
width of the upper pad portion 34, however, is preferably
relatively narrow, so as to concentrate its shape change impact to
the region near the valve annulus.
[0056] The upper pad portion 34 may be positioned near, but below,
the valve annulus. In other embodiments of the present invention,
the upper pad portion may be positioned directly on the exterior
surface of the annulus or somewhat above the annulus to contact the
left atrium wall. The position of the upper pad portion preferably
avoids direct compressive contact with important vascular structure
near or on the exterior surface of the heart. Significant coronary
vasculature often lies on or near the atrio-ventricular groove 36,
which corresponds with the posterior annular region of the mitral
valve. For this reason, it may be desirable to position the upper
pad portion onto the left atrial surface.
[0057] Anchor assembly 28 permits selection of a position that
causes valve annulus shape change relatively independent from the
positioning of the ventricular splints that cause ventricular shape
change. The incorporation of an anchor assembly 28 is most suitable
for instances where the desired shape change for the mitral valve
is relatively co-planar with the main ventricular shape change
splints. In addition, anchor assembly 28 provides for annulus shape
change without the need for an additional MV splint, such as that
shown in FIGS. 3a and 3b.
[0058] An alternative embodiment of a splint with a mitral valve
anchor assembly according to the invention is illustrated in FIG.
4b. In the embodiment of anchor assembly 28, shown in FIG. 4a, the
tension member 16 was connected to the spanning structure 32
approximately in the middle of the spanning structure 3, yielding a
relatively stable structure that remains substantially parallel to
the exterior surface of the heart. However, the embodiment of the
anchor assembly 28' shown in FIG. 4b places the ventricular shape
change caused by the lower pad portion 30' below the end of the
tension member 16'. The anchor assembly 28' illustrated in FIG. 4b
is similar to the anchor assembly 28 of FIG. 4a, except that the
tension member 16' is anchored within the lower pad portion 30'. In
order to provide mechanical balance to the anchor assembly, and to
give leverage to the upper pad portion 34' such that it can
properly alter the region of the valve annulus, a second spanning
structure 33 is provided to mechanically connect the anchor
assembly 28' to an anchor pad 14 of the splint disposed below the
superior-most splint. This second spanning structure 33 also may be
integrally formed with the anchor assembly 28' and, in turn, with
the anchor pad 14. Alternatively, the second spanning structure 33
can be a separate component connecting anchor assembly 28' and
anchor pad 14' once they are positioned with respect to the heart.
This could be done, for example, by mechanical fastening, such as
with screws or the like.
[0059] A further alternative anchor assembly 28" is shown in FIG.
4c. This anchor assembly 28" is similar to the anchor assembly 28
shown in FIG. 4a, except that anchor assembly 28" also includes one
or more additional papillary pad portions 35 connected to lower pad
portion 30" at a location substantially opposite to spanning
structure 32" The papillary pad portion or portions 35 serve to
provide one or more additional sites of deformation of the
ventricular wall, preferably to further reposition one or both
papillary muscles to aid in appoistion of the valve leaflets. The
papillary pad portions 35 may be formed integrally with the anchor
assembly 28" or may be separate and connected thereto via suitable
connection mechanisms.
[0060] In certain cases, the optimal orientation of shape change
for improving the mitral valve function may be significantly offset
from the position and orientation of transventricular splints 14.
It is therefore desirable to have an approach to cause mitral valve
shape change at positions away from the transventricular splints
14, and even more desirably, without the addition of another splint
structure traversing the ventricle.
[0061] FIG. 5a shows such an approach according to an embodiment of
the present invention. FIG. 5a shows an accessory anchor pad
structure 40 attached to a connection member, shown as a runner 42.
Runner 42 connects at its ends to both anchor pads 18 of preferably
the superior-most splint assembly 14. As an alternative, runner 42
may connect to one anchor pad 18 and extend between that anchor pad
18 and structure 40. The accessory pad structure 40 is positioned
at the location on the heart wall that yields the greatest
improvement in MVR, as determined with repeated probing and
deforming at the exterior of the heart proximate the mitral valve
annulus, as described above in connection with positioning the MV
splint 20 in FIGS. 3a and 3b.
[0062] Since runner 42 preferably connects to the two anchor pads
18 of the upper-most splint assembly 14, runner 42 generally runs
at approximately the same level on the heart wall as those anchor
pads 18. In one embodiment, accessory anchor pad structure 40 may
be of the same shape and material as the anchor pads 18. While this
embodiment may result in significantly improved MVR in some
instances, in another embodiment, accessory pad 40 may take a form,
including shape and material, similar to the anchor assemblies 28,
28', 28" shown in FIGS. 4a-4c. This latter configuration permits
positioning accessory pad 40 at a position higher than the level of
the anchor pads 18 of the superior-most transventricular splint,
resulting in even greater shape change to the mitral valve annulus.
Also according to this latter configuration, the preferred
construction of accessory pad 40 would include, in addition to
characteristics of anchor assembly 28, 28', 28", shown in FIGS.
4a-4c, a connecting mechanism 41 which would allow for adjustable
positioning and securing of the accessory pad 41 to runner 42. For
example, a locking screw 43 may be used to secure runner 42 to pad
41. Other mechanisms suitable for securing the pad 41 to the runner
42 and permitting adjustment of the pad position along the runner
are within the scope of the present invention. Runner 42 preferably
includes a wire-like, or braid-like, structure which secures to
each of the splint anchor pads 18 also through any suitable means,
such as, for example, a locking screw mechanism 44, a pinning
connection for a braid-like runner, or the like.
[0063] FIG. 5b shows an alternative embodiment for connecting an
accessory anchor pad assembly 50 to a runner 52 and for connecting
runner 52 to anchor pads 18. Each end of runner 52 connects to a
connection mechanism in the form of a cap 54. Each cap 54 locks in
place over a pad 18. At least one of the caps 54 includes an
adjustable locking mechanism for adjusting the length of the runner
52 between the caps 54, and also thereby adjusting the position of
the accessory pad 50 on the heart wall, and locking the runner 52
to cap 54.
[0064] In one embodiment, runner 52 is a braid formed of a high
strength polymer, such as that used in the tension members
described in the '049 application incorporated above. A suitable
connection mechanism includes the use of one or more pins 56 placed
through the braided runner 52 and connected to cap 54 through a
flange 58, for example, situated on the cap 54. This pinning
connection mechanism may be similar to the connection used for the
braided tension members and anchor pads shown and described in the
'049 application. The same connection mechanism may be used to
connect accessory pad 50 to braided runner 52. In an alternative
embodiment according to the present invention, the braided runner
52 may more directly connect to anchor pads 18, without the use of
caps 54, by, for example, a pinning securement mechanism
incorporated into the superior splint pads themselves. In another
contemplated embodiment, the external anchor pad assembly 50,
including the runner 52 and anchor pads 18, can be used without the
transventricular splint to improve valve function by causing a
shape change to the valve annulus without an overall shape change
to the left ventricle.
[0065] As mentioned above, a mechanism that may exacerbate MVR is
the relative rotation of the papillary muscles PM and the adjacent
left ventricular wall as the transventricular splints 14 are
tightened into position. This relative rotation results in slack in
some chordae and tightening in other chordae, which may "pull" one
valve leaflet (or portion of the leaflet) while "loosening" the
other valve leaflet (or portion of the leaflet).
[0066] FIG. 6 shows an embodiment of a device according to the
present invention that would alleviate this rotation phenomenon.
FIG. 6 shows an accessory splint 70 connected to the superior-most
ventricular splint 14 by a connecting bar 60. Accessory splint 70
and connecting bar 60 preferably are placed at approximately the
same level along the ventricular wall as splint 14. Splint 14
preferably is positioned near to, and in this case medial to, the
anterior papillary muscle PM. Accessory splint 70 then is
positioned through the septum S, across the left ventricle LV, and
through the ventricular free wall between the, papillary muscles
PM, similar to MV splint 20 described in connection with FIGS. 3a
and 3b but at about the same level as the superior splint 14.
[0067] Connecting bar 60 attaches to the ends of tension members 16
and 72 at their left ventricular "free wall" ends. Both tension
members 16 and 72 are tensioned, pressing connecting bar 60 into
the left ventricle and effecting shape change to the ventricle and
the mitral valve annulus. Connecting bar 60 prevents rotation of
the left ventricle LV in the region of the anterior papillary
muscle PM and causes uniform tensioning of the chordae associated
with that papillary muscle PM and any associated ventricular wall.
This is believed to lessen any degradation in MVR, and potentially
improve the MVR, because the papillary muscles PM are brought to a
more desired position, with less rotation, particularly as to the
anterior papillary muscle.
[0068] The embodiments of the present invention described in
connection with FIGS. 2a to 6 have been described in connection
with the use of transventricular splints used to geometrically
reshape a chamber of the heart and thereby lessen heart wall
stresses and reduce dilatation. While the devices and related
methods described herein would further benefit the ventricular
splinting procedure and its effects, the devices and related
methods of the present invention may be used independent of the
ventricular splinting to improve dilatation and instead be used for
repairing heart valves, and particularly mitral valves, without the
use of adjunctive ventricular splints. For example, a mitral valve
splint such as that shown in FIGS. 3a, 3b, and 3c could be utilized
without additional ventricular shape change splints.
[0069] Moreover, while many of the embodiments of the present
invention have been described in connection with modifications to
transventricular splinting structures, the same or similar
modifications may be made to external-type devices for causing
ventricular shape change. Examples of such external devices are
shown in co-pending U.S. patent application Ser. No. 09/157,486
("the '486 application") filed Sep. 21, 1998 and entitled "External
Stress Reduction Device and Method," the complete disclosure of
which is incorporated by reference herein. Modifying those external
devices in a similar manner as with the transventricular splints
will achieve beneficial impacts to the mitral valve function. For
example, the accessory anchor pad shown in FIGS. 5a and 5b could be
utilized in conjunction with an external stress reduction device,
as shown, for example, in FIG. 7. In FIG. 7, an external splint 199
having a generally U-shaped configuration and including an anterior
arm 199a and a posterior arm 199b, is positioned with respect to
the left ventricle to create a substantially bi-lobed shape. In a
preferred embodiment, the U-shaped external splint is made from a
material that permits the splint to elastically deform under
operational loads and also from a material that is biocompatible.
Examples of preferred materials include e-PTFE, or a polyester such
as Dacron, for example. Such a splint, as well as other suitable
external splints, is described in more detail in the '486
application incorporated above. As shown in FIG. 7, a runner 298,
similar to the runner described with reference to FIGS. 5a and 5b,
attaches at its ends to the arms 199a, 199b. An accessory anchor
pad 299, also similar to the accessory anchor assembly discussed
with reference to FIGS. 5a and 5b, attaches to the connecting
runner 298. The runner 298 and accesory anchor pad 299 are
positioned with respect to the heart so as to alter the shape of
the mitral valve annuls to assist in coaptation of the valve
leaflets. Alternatively, the runner and accessory anchor pad could
be positioned so as to provide a repositioning of the papillary
muscles, also to assist in coaptation of the valve leaflets.
[0070] It will be apparent to those skilled in the art that various
modifications and variations can be made in the devices and related
methods for improving mitral valve function of the present
invention and in construction of such devices without departing
from the scope or spirit of the invention. As an example, a
combination of devices depicted above may be used for achieving
improved mitral valve function. In one such combination, an
accessory splint such as MV splint 20 shown in FIGS. 3a and 3b may
include an anchor assembly 28 as shown in FIG. 4 and/or an accesory
anchor pad structure 40 or 50 shown in FIGS. 5a and 5b. Other
embodiments of the invention will be apparent to those skilled in
the art from consideration of the specification and practice of the
invention disclosed herein. The specification and examples are
exemplary only, with a true scope and spirit of the invention being
indicated by the following claims.
* * * * *