U.S. patent application number 10/622207 was filed with the patent office on 2004-01-29 for method and apparatus for performing catheter-based annuloplasty.
Invention is credited to Hlavka, Edwin J., Spence, Paul A..
Application Number | 20040019378 10/622207 |
Document ID | / |
Family ID | 25286207 |
Filed Date | 2004-01-29 |
United States Patent
Application |
20040019378 |
Kind Code |
A1 |
Hlavka, Edwin J. ; et
al. |
January 29, 2004 |
Method and apparatus for performing catheter-based annuloplasty
Abstract
The present invention relates to a minimally invasive method of
performing annuloplasty. According to one aspect of the present
invention, a method for performing a procedure on a mitral valve of
a heart includes inserting an implant into a left ventricle and
orienting the implant in the left ventricle substantially below the
mitral valve. The implant and tissue around the mitral valve are
connected and tension is provided to the implant, in one
embodiment, in order to substantially reduce an arc length
associated with the mitral valve. In another embodiment, the
implant is inserted into the left ventricle through the aorta and
the aortic valve.
Inventors: |
Hlavka, Edwin J.; (Palo
Alto, CA) ; Spence, Paul A.; (Louisville,
KY) |
Correspondence
Address: |
RITTER, LANG & KAPLAN
12930 SARATOGA AE. SUITE D1
SARATOGA
CA
95070
US
|
Family ID: |
25286207 |
Appl. No.: |
10/622207 |
Filed: |
July 18, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10622207 |
Jul 18, 2003 |
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09841968 |
Apr 24, 2001 |
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6619291 |
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Current U.S.
Class: |
623/2.11 |
Current CPC
Class: |
A61F 2/2448 20130101;
A61F 2/2466 20130101; A61B 2017/00243 20130101; Y10S 623/904
20130101; A61F 2/2445 20130101; A61B 2017/048 20130101 |
Class at
Publication: |
623/2.11 |
International
Class: |
A61F 002/24 |
Claims
What is claimed is:
1. A method for performing a procedure on a mitral valve of a
heart, the method comprising: inserting at least one implant into a
left ventricle of the heart; positioning the at least one implant
with respect to the mitral valve, wherein positioning the implant
includes orienting the implant in the left ventricle substantially
below the mitral valve; and attaching the implant to tissue located
near the mitral valve.
2. A method as recited in claim 1 further including: reducing an
arc length of the implant, wherein reducing the arc length of the
implant substantially reduces an arc length associated with the
mitral valve.
3. A method as recited in claim 1 wherein inserting the implant
into the left ventricle includes: introducing the implant into an
aorta; and passing the implant through an aortic valve interposed
between the aorta and the left ventricle.
4. A method as recited in claim 3 further including: introducing a
guide element into the left ventricle, the guide element being
configured to be positioned in the left ventricle between a plane
of the mitral valve and a plane associated with papillary muscles
of the heart, wherein inserting the implant into the left ventricle
includes positioning the implant such that the implant uses the
guide element as a track.
5. A method as recited in claim 4 further including: removing the
guide element from the left ventricle after attaching the implant
to the tissue.
6. A method as recited in claim 4 wherein introducing the guide
element into the left ventricle includes: introducing a first
catheter assembly into the aorta, the first catheter assembly
including an angled catheter, and a gutter catheter, wherein the
angled catheter substantially carries the gutter catheter, the
angled catheter being arranged to facilitate positioning of the
gutter catheter; positioning the gutter catheter beneath the mitral
valve between the plane of the mitral valve and the plane
associated with the papillary muscles, wherein positioning the
gutter catheter includes positioning the gutter catheter along a
wall of the left ventricle; and inserting the guide element into a
lumen of the gutter catheter.
7. A method as recited in claim 6 wherein introducing the guide
element into the left ventricle further includes: anchoring the
guide element against the wall.
8. A method as recited in claim 4 wherein attaching the implant to
the tissue includes: introducing a catheter into the left ventricle
using the guide element as a track, wherein the catheter includes
at least one pointed wire, the pointed wire including a tip
section, the pointed wire further being configured to carry a
coupling element, the tip section being configured for insertion
into the implant and the tissue; pushing the tip section through
the implant and the tissue, wherein pushing the tip section through
the implant and the tissue positions at least a part of the
coupling element on an atrial side of the tissue; and retracting
the tip section from the implant and the tissue, wherein retracting
the tip section causes the coupling element to substantially couple
the implant with the tissue.
9. A method as recited in claim 8 wherein the coupling element is a
T-bar.
10. A method as recited in claim 3 further including: introducing a
guide element into the left ventricle, the guide element being
configured to be positioned in the left ventricle in a region of
the left ventricle substantially bounded by leaflets of the mitral
valve, the papillary muscles of the heart, a ventricular wall, and
cordae tendonae, wherein inserting the implant into the left
ventricle includes positioning the implant such that the implant
uses the guide element as a track.
11. A method as recited in claim 1 further including: adjusting an
arc length of the implant.
12. A method as recited in claim 1 wherein the tissue is fibrous
tissue.
13. A method for performing annuloplasty on a mitral valve of a
heart, the method comprising: inserting a first catheter assembly
into a left ventricle through an aorta of the heart and an aortic
valve of the heart; positioning a guide element along a wall of the
left ventricle beneath the mitral valve using the first catheter
assembly; positioning at least one implant in the left ventricle
beneath the mitral valve using the guide element as a guide; and
connecting the at least one implant to tissue near the mitral
valve.
14. A method as recited in claim 13 wherein the implant includes a
shortening means, and the method further includes: shortening the
implant using the shortening means, wherein shortening the implant
substantially reduces an arc length of the mitral valve.
15. A method as recited in claim 13 wherein the first catheter
assembly includes a first catheter and a second catheter, the
second catheter being located at least partially within the first
catheter, the first catheter being arranged to facilitate the
positioning of the second catheter along the wall of the left
ventricle, and wherein positioning the guide element along the wall
includes: inserting the guide element through the second catheter;
and anchoring the guide element against the wall.
16. A method as recited in claim 15 further including: removing the
first catheter and the second catheter from the left ventricle; and
inserting a third catheter into the left ventricle, the third
catheter configured to carry the implant and to use the guide
element as a guide.
17. A method as recited in claim 13 wherein connecting the implant
to the tissue near the mitral valve includes: inserting a fourth
catheter into the left ventricle, the fourth catheter being
configured to carry a first connection element; and inserting the
first connection element through the implant and the tissue such
that the implant and the tissue are coupled by the first connection
element.
18. A method as recited in claim 17 wherein the fourth catheter is
further configured to carry a second connection element, the method
further including: inserting the second connection element through
the implant and the tissue such that the implant and the tissue are
coupled by the second connection element.
19. A method as recited in claim 17 wherein positioning the implant
in the left ventricle beneath the mitral valve using the guide
element further includes: inserting at least one balloon into the
left ventricle; and inflating the balloon, wherein inflating the
balloon positions the implant generally against the mitral
valve.
20. A method as recited in claim 17 wherein positioning the implant
in the left ventricle beneath the mitral valve using the guide
element further includes: inserting at least one expandable element
into the left ventricle; and expanding the expandable element,
wherein expanding the expandable element positions the implant
generally against the mitral valve.
21. A method for accessing a left ventricle of a heart, the method
comprising: introducing an elongated body into an aorta of the
heart; passing at least a portion of the elongated body through an
aortic valve positioned between the aorta and the left ventricle;
and positioning the portion of the elongated body in the left
ventricle.
22. A method as recited in claim 21 wherein locating the portion of
the elongated body in the left ventricle includes positioning the
portion of the elongated body between a plane associated with a
mitral valve of the heart and a plane associated with papillary
muscles of the left ventricle.
23. A method as recited in claim 22 wherein the elongated body is
an implant, and locating the portion of the elongated body in the
left ventricle further includes positioning the implant
substantially against tissue near the mitral valve.
24. A method as recited in claim 22 wherein the elongated body is a
catheter.
25. A method as recited in claim 24 wherein the catheter is
arranged to provide at least one plication in the tissue near the
mitral valve.
26. A method as recited in claim 21 wherein locating the portion of
the elongated body in the left ventricle includes positioning the
portion of the elongated body between a plane associated with a
mitral valve of the heart, a plane associated with papillary
muscles of the left ventricle, cordae tendonae of the left
ventricle, and a wall of the left ventricle.
27. A method as recited in claim 26 wherein the elongated body is
an implant, and locating the portion of the elongated body in the
left ventricle further includes positioning the implant
substantially against tissue near the mitral valve.
28. A method as recited in claim 26 wherein the elongated body is a
catheter.
29. A method as recited in claim 28 wherein the catheter is
arranged to provide at least one plication in the tissue near the
mitral valve.
30. A method as recited in claim 21 further including: introducing
an expandable element into the aorta, wherein the expandable
element is substantially unexpanded; positioning the expandable
element in the left ventricle; and expanding the expandable
element, wherein expanding the expandable element causes the
portion of the elongated body to contact a target region of the
heart.
31. A method as recited in claim 30 wherein the target region of
the heart is tissue near the a mitral valve of the heart.
32. A method for performing annuloplasty, the method comprising:
accessing a left ventricle of a heart to provide an implant to the
left ventricle; and coupling the implant to tissue near a mitral
valve of the heart, wherein the implant is coupled to a ventricular
side of the mitral valve.
33. A method as recited in claim 32 further including: shaping the
implant, wherein shaping the implant substantially reduces an arc
length associated with the mitral valve.
34. A method as recited in claim 33 wherein shaping the implant
includes substantially reducing an arc length of the implant by
providing tension to the implant.
35. A method as recited in claim 32 wherein accessing the left
ventricle includes inserting an elongated body into the left
ventricle through an aorta and an aortic valve of the heart.
36. A method as recited in claim 35 wherein providing the elongated
body into the left ventricle includes inserting the elongated body
into the left ventricle between a plane associated with the mitral
valve and a plane associated with papillary muscles of the
heart.
37. A method as recited in claim 35 wherein providing the elongated
body into the left ventricle includes inserting the elongated body
into a region of the left ventricle substantially defined between a
plane associated with the mitral valve, a plane associated with
papillary muscles of the heart, a wall of the left ventricle, and
cordae tendonae of the heart.
38. A device for use in an annuloplasty procedure, the device
comprising: a member, the member being arranged to be substantially
shortened with respect to itself when tension is applied to the
member; a mesh, the mesh being arranged over the member; and a
tensioning element, the tensioning element being configured to
apply tension to the member, wherein when the device is coupled to
tissue surrounding a mitral valve of a heart, the tensioning
element is configured to cause the device to reduce an arc length
associated with the mitral valve.
39. A device according to claim 38 wherein the device is suitable
for being positioned on a ventricular side of the mitral valve.
40. A device according to claim 39 wherein the tensioning element
is continuously adjustable to alter the tension applied to the
member.
41. A device according to claim 39 wherein the tensioning element
is at least partially located within the member.
42. A device according to claim 39 further including: a coupler,
the coupler being arranged to extend through the member and the
mesh, the coupler further being arranged to couple the device to
the tissue.
43. A device according to claim 42 wherein the coupler is a
T-bar.
44. A device for use in an annuloplasty procedure, the device
comprising: a collapsible member, wherein the collapsible member is
movable between an extended position for insertion into a left
ventricle through a catheter and a short position; and a shortening
device, the shortening device being operable to move the
compressible member between the extended position and the short
position, wherein the device is positioned to reduce an opening of
a mitral valve when the device is in the short position.
45. A device according to claim 44 further including: a mesh
covering, the mesh covering extending over at least a portion of
the compressible member.
46. A device according to claim 44 wherein the device is suitable
for being coupled to tissue near the mitral valve.
47. A device according to claim 46 further including: a coupler,
the coupler being configured to extend through the structure and
the mesh, the coupler further being arranged to couple the device
to the tissue.
48. A system for performing annuloplasty on a mitral valve of a
heart, the system comprising: a catheter assembly configured for
insertion through an aorta of the heart into a left ventricle of
the heart to reach a region of the left ventricle substantially
below the mitral valve; a guide element shaped for insertion into
the catheter assembly, the guide element having an anchorable
feature; and an implant, the implant being shaped for insertion
over the guide element into the left ventricle substantially below
the mitral valve, wherein the implant is configured to be connected
to tissue of the heart.
49. A system according to claim 48 wherein the catheter assembly
includes a delivery tube and a gutter catheter, the gutter catheter
being positioned at least partially within the delivery tube,
wherein a portion of the gutter catheter is configured to be
positioned substantially within a region of the left ventricle
defined between a plane associated with the papillary muscles of
the left ventricle and a plane associated with the mitral
valve.
50. A system according to claim 49 wherein the guide element is
shaped for insertion into a lumen of the gutter catheter.
51. A system according to claim 48 wherein the catheter assembly
includes a delivery tube and a gutter catheter, the gutter catheter
being positioned at least partially within the delivery tube,
wherein a portion of the gutter catheter is configured to be
positioned substantially within a region of the left ventricle
defined between a plane associated with the papillary muscles of
the left ventricle, a plane associated with the mitral valve,
cordae tendonae of the left ventricle, and a wall of the left
ventricle.
52. A system according to claim 48 further including: a delivery
catheter, the connection catheter configured to provide a
connection element, wherein the connection element is configured to
connect the implant to the tissue.
53. A system according to claim 52 wherein the tissue is located
near the mitral valve.
55. A system according to claim 53 wherein the tissue is fibrous
tissue.
56. A system according to claim 51 wherein the implant includes a
shortening element, the shortening element being arranged to
shorten an arc length associated with the implant, wherein
shortening the arc length associated with the implant reduces an
arc length associated with a posterior leaflet of the mitral
valve.
57. A system according to claim 51 wherein the implant is
configured to have a shortened state and an unshortened state,
wherein when the implant is inserted over the guide element, the
implant is in the unshortened state, and wherein when the arc
length associated with the implant is shortened, the implant is in
the shortened state.
58. A system according to claim 48 wherein the guide element is
formed from one of a stainless steel material and a shape memory
material.
59. A system according to claim 48 wherein the catheter assembly is
at least partially formed from at least one of a nylon material and
a urethane material.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of Invention
[0002] The present invention relates generally to techniques for
treating mitral valve insufficiencies such as mitral valve leakage.
More particularly, the present invention relates to systems and
methods for treating a leaking mitral valve in a minimally invasive
manner.
[0003] 2. Description of the Related Art
[0004] Congestive heart failure (CHF), which is often associated
with an enlargement of the heart, is a leading cause of death. As a
result, the market for the treatment of CHF is becoming
increasingly prevalent. For instance, the treatment of CHF is a
leading expenditure of Medicare and Medicaid dollars in the United
States of America. Typically, the treatment of CHF enables many who
suffer from CHF to enjoy an improved quality of life.
[0005] Referring initially to FIG. 1, the anatomy of a heart,
specifically the left side of a heart, will be described. The left
side of a heart 104 includes a left atrium 108 and a left ventricle
112. An aorta 114 receives blood from left ventricle 112 through an
aortic valve 120, which serves to prevent regurgitation of blood
back into left ventricle 112. A mitral valve 116 is disposed
between left atrium 108 and left ventricle 112, and effectively
controls the flow of blood between left atrium 108 and left
ventricle 112.
[0006] Mitral valve 116, which will be described below in more
detail with respect to FIG. 2a, includes an anterior leaflet and a
posterior leaflet that are coupled to cordae tendonae 124 which
serve as "tension members" that prevent the leaflets of mitral
valve 116 from opening indiscriminately. When left ventricle 112
contracts, cordae tendonae 124 allow the anterior leaflet to open
upwards until limited in motion by cordae tendonae 124. Normally,
the upward limit of opening corresponds to a meeting of the
anterior and posterior leaflets and the prevention of backflow.
Cordae tendonae 124 arise from a columnae carnae 128 or, more
specifically, a musculi papillares of columnae carnae 128.
[0007] Left ventricle 112 includes trabeculae 132 which are fibrous
cords of connective tissue that are attached to wall 134 of left
ventricle 112. Trabeculae 132 are also attached to an
interventricular septum 136 which separates left ventricle 112 from
a right ventricle (not shown) of heart 104. Trabeculae 132 are
generally located in left ventricle 112 below columnae carnae
128.
[0008] FIG. 2a is a cut-away top-view representation of mitral
valve 116 and aortic valve 120. Aortic valve 120 has a valve wall
204 that is surrounded by a skeleton 208a of fibrous material.
Skeleton 208a may generally be considered to be a fibrous structure
that effectively forms a ring around aortic valve 120. A fibrous
ring 208b, which is substantially the same type of structure as
skeleton 208a, extends around mitral valve 116. Mitral valve 116
includes an anterior leaflet 212 and a posterior leaflet 216, as
discussed above. Anterior leaflet 212 and posterior leaflet 216 are
generally thin, flexible membranes. When mitral valve 116 is closed
(as shown in FIG. 2a), anterior leaflet 212 and posterior leaflet
216 are generally aligned and contact one another to create a seal.
Alternatively, when mitral valve 116 is opened, blood may flow
through an opening created between anterior leaflet 212 and
posterior leaflet 216.
[0009] Many problems relating to mitral valve 116 may occur and
these insufficiencies may cause many types of ailments. Such
problems include, but are not limited to, mitral regurgitation.
Mitral regurgitation, or leakage, is the backflow of blood from
left ventricle 112 into the left atrium 108 due to an imperfect
closure of mitral valve 116. That is, leakage often occurs when a
gap is created between anterior leaflet 212 and posterior leaflet
216.
[0010] In general, a relatively significant gap may exist between
anterior leaflet 212 and posterior leaflet 216 (as shown in FIG.
2b) for a variety of different reasons. For example, a gap may
exist due to congenital malformations, because of ischemic disease,
or because a heart has been damaged by a previous heart attack. A
gap may also be created when congestive heart failure, e.g.,
cardiomyopathy, or some other type of distress causes a heart to be
enlarged. When a heart is enlarged, the walls of the heart, e.g.,
wall 134 of a left ventricle, may stretch or dilate, causing
posterior leaflet 216 to stretch. It should be appreciated that
anterior leaflet 212 generally does not stretch. As shown in FIG.
2b, a gap 220 between anterior leaflet 212 and stretched posterior
leaflet 216' is created when wall 134' stretches. Hence, due to the
existence of gap 220, mitral valve 116 is unable to close properly,
and may begin to leak.
[0011] Leakage through mitral valve 116 generally causes a heart to
operate less efficiently, as the heart must work harder to maintain
a proper amount of blood flow therethrough. Leakage through mitral
valve 116, or general mitral insufficiency, is often considered to
be a precursor to CHF. There are generally different levels of
symptoms associated with heart failure. Such levels are classified
by the New York Heart Association (NYHA) functional classification
system. The levels range from a Class 1 level which is associated
with an asymptomatic patient who has substantially no physical
limitations to a Class 4 level which is associated with a patient
who is unable to carry out any physical activity without
discomfort, and has symptoms of cardiac insufficiency even at rest.
In general, correcting for mitral valve leakage may be successful
in allowing the NYHA classification grade of a patient to be
reduced. For instance, a patient with a Class 4 classification may
have his classification reduced to Class 3 and, hence, be
relatively comfortable at rest.
[0012] Treatments used to correct for mitral valve leakage or, more
generally, CHF, are typically highly invasive, open-heart surgical
procedures. Ventricular assist devices such as artificial hearts
may be implanted in a patient whose own heart is failing. The
implantation of a ventricular assist device is often expensive, and
a patient with a ventricular assist device must be placed on
extended anti-coagulant therapy. As will be appreciated by those
skilled in the art, anti-coagulant therapy reduces the risk of
blood clots being formed, as for example, within the ventricular
assist device. While reducing the risks of blood clots associated
with the ventricular assist device is desirable, anti-coagulant
therapies may increase the risk of uncontrollable bleeding in a
patient, e.g., as a result of a fall, which is not desirable.
[0013] Rather than implanting a ventricular assist device,
bi-ventricular pacing devices similar to pace makers may be
implanted in some cases, e.g., cases in which a heart beats
inefficiently in a particular asynchronous manner. While the
implantation of a bi-ventricular pacing device may be effective,
not all heart patients are suitable for receiving a bi-ventricular
pacing device. Further, the implantation of a bi-ventricular pacing
device is expensive.
[0014] Open-heart surgical procedures which are intended to correct
for mitral valve leakage, specifically, involve the implantation of
replacement valves. Valves from animals, e.g., pigs, may be used to
replace a mitral valve 116 in a human. While the use of a pig valve
may relatively successfully replace a mitral valve, such valves
generally wear out, thereby requiring additional open surgery at a
later date. Mechanical valves, which are less likely to wear out,
may also be used to replace a leaking mitral valve. However, when a
mechanical valve is implanted, there is an increased risk of
thromboembolism, and a patient is generally required to undergo
extended anti-coagulant therapies.
[0015] A less invasive surgical procedure involves heart bypass
surgery associated with a port access procedure. For a port access
procedure, the heart may be accessed by cutting a few ribs, as
opposed to opening the entire chest of a patient. In other words, a
few ribs may be cut in a port access procedure, rather than opening
a patient's sternum.
[0016] One open-heart surgical procedure that is particularly
successful in correcting for mitral valve leakage and, in addition,
mitral regurgitation, is an annuloplasty procedure. During an
annuloplasty procedure, an annuloplasty ring may be implanted on
the mitral valve to cause the size of a stretched mitral valve 116
to be reduced to a relatively normal size. FIG. 3 is a schematic
representation of an annuloplasty ring. An annuloplasty ring 304 is
shaped approximately like the contour of a normal mitral valve.
That is, annuloplasty ring 304 is shaped substantially like the
letter "D." Typically, annuloplasty ring 304 may be formed from a
rod or tube of biocompatible material, e.g., plastic, that has a
DACRON mesh covering.
[0017] In order for annuloplasty ring 304 to be implanted, a
surgeon surgically attaches annuloplasty ring 304 to the mitral
valve on the atrial side of the mitral valve. Conventional methods
for installing ring 304 require open-heart surgery which involve
opening a patient's sternum and placing the patient on a heart
bypass machine. As shown in FIG. 4, annuloplasty ring 304 is sewn
to a posterior leaflet 318 and an anterior leaflet 320 of a top
portion of mitral valve 316. In sewing annuloplasty ring 304 onto
mitral valve 316, a surgeon generally alternately acquires a
relatively large amount of tissue from mitral tissue, e.g., a
one-eighth inch bite of tissue, using a needle and thread, followed
by a smaller bite from annuloplasty ring 304. Once a thread has
loosely coupled annuloplasty ring 304 to mitral valve tissue,
annuloplasty ring 304 is slid onto mitral valve 316 such that
tissue that was previously stretched out, e.g., due to an enlarged
heart, is effectively pulled in using tension applied by
annuloplasty ring 304 and the thread which binds annuloplasty ring
304 to the mitral valve tissue. As a result, a gap, such as gap 220
of FIG. 2b, between anterior leaflet 320 and posterior leaflet 318
may be substantially closed off. After the mitral valve is shaped
by ring 304, the anterior and posterior leaflets 320, 318 will
reform to create a new contact line and will enable mitral valve
318 to appear and to function as a normal mitral valve.
[0018] Once implanted, tissue generally grows over annuloplasty
ring 304, and a line of contact between annuloplasty ring 304 and
mitral valve 316 will essentially enable mitral valve 316 to appear
and function as a normal mitral valve. Although a patient who
receives annuloplasty ring 304 may be subjected to anti-coagulant
therapies, the therapies are not extensive, as a patient is only
subjected to the therapies for a matter of weeks, e.g., until
tissue grows over annuloplasty ring 304.
[0019] A second surgical procedure which is generally effective in
reducing mitral valve leakage involves placing an edge-to-edge
suture in the mitral valve. With reference to FIG. 5, such a
surgical procedure, e.g., an Alfieri stitch procedure or a bow-tie
repair procedure, will be described. An edge-to-edge stitch 404 is
used to stitch together an area at approximately the center of a
gap 408 defined between an anterior leaflet 420 and a posterior
leaflet 418 of a mitral valve 416. Once stitch 404 is in place,
stitch 404 is pulled in to form a suture which holds anterior
leaflet 420 against posterior leaflet 418, as shown. By reducing
the size of gap 408, the amount of leakage through mitral valve 416
may be substantially reduced.
[0020] Although the placement of edge-to-edge stitch 404 is
generally successful in reducing the amount of mitral valve leakage
through gap 408, edge-to-edge stitch 404 is conventionally made
through open-heart surgery. In addition, the use of edge-to-edge
stitch 404 is generally not suitable for a patient with an
enlarged, dilated heart, as blood pressure causes the heart to
dilate outward, and may put a relatively large amount of stress on
edge-to-edge stitch 404. For instance, blood pressure of
approximately 120/80 or higher is typically sufficient to cause the
heart to dilate outward to the extent that edge-to-edge stitch 404
may become undone, or tear mitral valve tissue.
[0021] While invasive surgical procedures have proven to be
effective in the treatment of mitral valve leakage, invasive
surgical procedures often have significant drawbacks. Any time a
patient undergoes open-heart surgery, there is a risk of infection.
Opening the sternum and using a cardiopulmonary bypass machine has
also been shown to result in a significant incidence of both short
and long term neurological deficits. Further, given the complexity
of open-heart surgery, and the significant associated recovery
time, people who are not greatly inconvenienced by CHF symptoms,
e.g., people at a Class 1 classification, may choose not to have
corrective surgery. In addition, people who most need open heart
surgery, e.g., people at a Class 4 classification, may either be
too frail or too weak to undergo the surgery. Hence, many people
who may benefit from a surgically repaired mitral valve may not
undergo surgery.
[0022] Therefore, what is needed is a minimally invasive treatment
for mitral valve leakage. Specifically, what is desired is a method
for reducing leakage between an anterior leaflet and a posterior
leaflet of a mitral valve that does not require conventional
surgical intervention.
SUMMARY OF THE INVENTION
[0023] The present invention relates to a non-invasive method of
performing annuloplasty. According to one aspect of the present
invention, a method for performing a procedure on a mitral valve of
a heart includes inserting an implant into a left ventricle and
orienting the implant in the left ventricle substantially below the
mitral valve. The implant may be attached to tissue near the mitral
valve. In one embodiment, the implant is shortened in order to
substantially reduce an arc length associated with the mitral
valve. In another embodiment, the implant is inserted to the left
ventricle through the aorta and the aortic valve.
[0024] In still another embodiment, connecting the implant and the
tissue includes introducing a catheter into the left ventricle
using a guide element as a track. The catheter includes at least
one pointed wire which carries a coupling element and has a tip
section that may be substantially pushed through the implant and
the tissue to substantially couple the implant with the tissue. In
such an embodiment, the coupling element may be a T-bar.
[0025] Performing an annuloplasty on a mitral valve by accessing
the left ventricle of the heart using a catheter enables
complicated surgical procedures to be avoided when treating mitral
valve leakage. Avoiding surgical procedures generally makes
annuloplasty more accessible to patients who may benefit from
annuloplasty. As mitral valve leakage is often considered to be an
early indicator of congestive heart failure, a non-invasive
annuloplasty procedure which corrects for leakage problems may
greatly improve the quality of life of many patients who might not
be suitable for invasive annuloplasty procedures.
[0026] According to another aspect of the present invention, a
method for accessing the left ventricle of a heart includes
introducing an elongated body into the aorta, and passing at least
a portion of the elongated body through the aortic valve. Once the
portion is passed through the aortic valve, the portion is located,
or positioned, in the left ventricle. In one embodiment, locating
the portion in the left ventricle involves positioning the portion
in the space between a plane associated with the mitral valve and a
plane associated with the papillary muscles of the left ventricle.
In such an embodiment, the elongated body may be an implant, and
locating the portion in the left ventricle may further involve
positioning the implant substantially against tissue near the
mitral valve.
[0027] In accordance with still another aspect of the present
invention, a method for performing annuloplasty includes accessing
the left ventricle to provide an implant such as a tensionable
arrangement to the left ventricle. Once the left ventricle is
accessed, the tensionable arrangement is coupled to fibrous tissue
around a mitral valve of the heart. The tensionable arrangement is
coupled to a ventricular side of the mitral valve. Finally, the
tensionable arrangement is tensioned such that it substantially
reduces an arc length associated with the mitral valve. In one
embodiment, the tensionable arrangement is an implant, and
tensioning the tensionable arrangement involves substantially
collapsing the implant.
[0028] According to yet another aspect of the present invention, a
device which is suitable for use in an annuloplasty procedure
includes a structure, a mesh, and a tensioning element. The
structure is a spring-like element that is configured to be
compressed onto itself when tension is applied. The mesh is a woven
mesh that is arranged over the structure, and the tensioning
element is arranged to apply tension to the structure. The device
is such that when the device is coupled to fibrous tissue in
proximity to the mitral valve of a heart, the tensioning element
causes the device to reduce an arc length associated with the
mitral valve. In one embodiment, device is suitable for being
coupled to a ventricular side of the mitral valve. In another
embodiment, the device includes a coupler which extends through the
structure and the mesh to couple the device to the fibrous tissue.
In such an embodiment, the coupler may take the form of a
T-bar.
[0029] In accordance with still another aspect of the present
invention, a device for use in an annuloplasty procedure includes a
compressible member and a shortening device. The compressible
member is movable between an open uncompressed position for
insertion into a left ventricle through a catheter and a closed
position. The shortening device is operable to move the
compressible member between the open uncompressed position and the
closed position. In general, the device is positioned to reduce an
opening of a mitral valve. In one embodiment, the device also
includes mesh covering that extends over at least a portion of the
compressible member.
[0030] These and other advantages of the present invention will
become apparent upon reading the following detailed descriptions
and studying the various figures of the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] The invention may best be understood by reference to the
following description taken in conjunction with the accompanying
drawings in which:
[0032] FIG. 1 is a cross-sectional front-view representation of the
left side of a human heart.
[0033] FIG. 2a is a cut-away top-view representation of the mitral
valve and the aortic valve of FIG. 1.
[0034] FIG. 2b is a cut-away representation of a stretched mitral
valve and an aortic valve.
[0035] FIG. 3 is a representation of an annular ring that is
suitable for use in performing a conventional annuloplasty
procedure.
[0036] FIG. 4 is a representation of a mitral valve and an aortic
valve after the annular ring of FIG. 3 has been implanted.
[0037] FIG. 5 is a representation of a mitral valve and an aortic
valve after a single edge-to-edge suture has been applied to reduce
mitral regurgitation.
[0038] FIG. 6a is a representation of a delivery tube and a
J-catheter in accordance with an embodiment of the present
invention.
[0039] FIG. 6b is a cut-away front view of the left side of a heart
in which the delivery tube and the J-catheter of FIG. 6a have been
inserted in accordance with an embodiment of the present
invention.
[0040] FIG. 7a is a representation of a catheter assembly in
accordance with an embodiment of the present invention.
[0041] FIG. 7b is a cross-sectional representation of the catheter
assembly of FIG. 7a in accordance with an embodiment of the present
invention.
[0042] FIG. 7c is a cut-away top-view representation of a left
ventricle in which the gutter catheter of FIGS. 7a and 7b has been
positioned in accordance with an embodiment of the present
invention.
[0043] FIG. 8 is a cut-away top-view representation of a left
ventricle in which a guide wire has been positioned in accordance
with an embodiment of the present invention.
[0044] FIG. 9a is a representation of a portion of an implant in
accordance with an embodiment of the present invention.
[0045] FIG. 9b is a cut-away top-view representation of a left
ventricle in which an implant has been positioned in accordance
with an embodiment of the present invention.
[0046] FIG. 9c is a cross-sectional front-view representation of a
left ventricle in which the implant of FIG. 9b and a balloon have
been inserted in accordance with an embodiment of the present
invention.
[0047] FIG. 10 is a representation of a T-bar delivery catheter in
accordance with an embodiment of the present invention.
[0048] FIG. 11a illustrates an implant that is coupled to fibrous
tissue around a mitral valve before tension has been applied to the
implant in accordance with an embodiment of the present
invention.
[0049] FIG. 11b illustrates the implant of FIG. 1 a after tension
has been applied to the implant in accordance with an embodiment of
the present invention.
[0050] FIG. 12 is a process flow diagram which illustrates the
steps associated with one method of performing annuloplasty using a
catheter in accordance with an embodiment of the present
invention.
[0051] FIG. 13a is a cut-away representation of a left ventricle in
which a catheter has been inserted in accordance with a second
embodiment of the present invention.
[0052] FIG. 13b is a cross-sectional representation of a left
ventricle in which the catheter of FIG. 13a has been inserted in
accordance with the second embodiment of the present invention.
[0053] FIG. 13c is a representation of a clip which is coupled to
an anterior leaflet and a posterior leaflet in accordance with the
second embodiment of the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0054] Invasive, open-heart surgical procedures are generally
effective in the treatment of mitral valve leakage. However,
open-heart surgical procedures may be particularly hazardous to
some patients, e.g., frail patients or patients who are considered
as being very ill, and undesirable to other patients, e.g.,
patients who are asymptomatic and do not wish to undergo a surgical
procedure. As such, open-heart surgical procedures to correct
mitral valve leakage or, more generally, mitral valve
insufficiency, are not suitable for many patients who would likely
benefit from reducing or eliminating the mitral valve leakage.
[0055] A catheter-based annuloplasty procedure enables annuloplasty
to be performed on a patient without requiring that the patient
undergo open-heart surgery, or be placed on cardiopulmonary bypass.
Catheters may be introduced into the left ventricle of a heart
through the aorta to position a guide wire and an implant on the
ventricular side of a mitral valve, i.e., under a mitral valve.
Catheters may also be used to couple the implant to fibrous tissue
associated with the skeleton of the heart around the mitral valve,
and to reduce leakage between an anterior leaflet of the mitral
valve and a posterior leaflet of the mitral valve by applying
tension to the implant.
[0056] The use of catheters to perform an annuloplasty procedure
enables the annuloplasty procedure to be performed without
open-heart surgery, and without a bypass procedure. Recovery time
associated with the annuloplasty, as well as the risks associated
with annuloplasty, may be substantially minimized. As a result,
annuloplasty becomes a more accessible procedure, since many
patients who might previously not have received treatment for
mitral valve leakage, e.g., frail patients and asymptomatic
patients, may choose to undergo catheter-based annuloplasty.
[0057] To begin a catheter-based annuloplasty procedure, a delivery
tube and a J-catheter may be inserted into a left ventricle of the
heart through the aorta. Inserting the delivery tube and the
J-catheter through the aorta enables the left ventricle of the
heart to be reached substantially without coming into contact with
trabeculae or the cordae tendonae in the left ventricle. FIG. 6a is
a diagrammatic representation of a delivery tube and a J-catheter
in accordance with an embodiment of the present invention. Delivery
tube 604 has a substantially circular cross section, and is
configured to receive a J-catheter 608. J-catheter 608 is arranged
to move longitudinally through and opening in delivery tube 604 as
needed.
[0058] In general, delivery tube 604 is an elongated body which may
be formed from a flexible, durable, biocompatible material such as
nylon, urethane, or a blend of nylon and urethane, e.g.,
PEBAX.RTM.. Likewise, J-catheter 608, which is also an elongated
body, may also be formed from a biocompatible material. A material
used to form J-catheter 608 is typically also relatively flexible.
In the described embodiment, a tip of J-catheter 608 is rigid
enough to allow the tip of J-catheter 608 to maintain a relatively
curved shape, e.g., a "J" shape. The curve in J-catheter 608 is
configured to facilitate the positioning of a gutter catheter, as
will be described below with respect to FIGS. 7a-c.
[0059] FIG. 6b is a schematic representation of delivery tube 604
and J-catheter 608 positioned within a heart in accordance with an
embodiment of the present invention. As shown, after delivery tube
604 and J-catheter 608 are effectively "snaked" or inserted through
a femoral artery, portions of delivery tube 604 and of J-catheter
608 are positioned within an aorta 620 of a heart 616. A tip 626 of
J-catheter 608, which is substantially oriented at a right angle
from the body of J-catheter 608, and an end of delivery tube 604
are oriented such that they pass through an aortic valve 630.
Hence, an end of delivery tube 604 and tip 626 are positioned at a
top portion of left ventricle 624, where wall 632 of left ventricle
624 is relatively smooth. The relative smoothness of the top
portion of left ventricle 624 enables a catheter to be properly
positioned within left ventricle 624 by guiding the tip of the
catheter along wall 632. In one embodiment, tip 626 is oriented
such that it is positioned approximately just below a mitral valve
628 on the ventricular side of mitral valve 628.
[0060] Once positioned within left ventricle 624, J-catheter 608
may be rotated within delivery tube 604 such that tip 626 is may
enable a gutter catheter fed therethrough to run along the contour
of wall 632. Typically, the gutter catheter runs along the contour
of wall 632 in an area that is effectively defined between a plane
associated with papillary muscles 640, a plane associated with the
posterior leaflet of mitral valve 628, cordae tendonae 642, and
wall 632. A "gutter" is located in such an area or region and, more
specifically, is positioned substantially right under mitral valve
628 where there is a relatively insignificant amount of
trabeculae.
[0061] With reference to FIGS. 7a-7c, a gutter catheter will be
described in accordance with an embodiment of the present
invention. A gutter catheter 704, which is part of a catheter
assembly 702 as shown in FIG. 7a, is arranged to be extended
through J-catheter 626 such that gutter catheter 704 may be steered
within a left ventricle just beneath a mitral valve. Gutter
catheter 704, which may include a balloon tip (not shown), is
typically formed from a flexible material such as nylon, urethane,
or PEBAX.RTM.. In one embodiment, gutter catheter 704, which is
steerable, may be formed using a shape memory material.
[0062] As shown in FIGS. 7a and FIG. 7b, which represents a cross
section of catheter assembly 702 taken at a location 710, gutter
catheter 704 is at least partially positioned within J-catheter 608
which, in turn, is at least partially positioned within delivery
tube 604. Gutter catheter 704 may be free to rotate within and
extend through J-catheter 608, while J-catheter 608 may be free to
rotate within and extend through delivery tube 604.
[0063] Referring next to FIG. 7c, the positioning of gutter
catheter 704 within a left ventricle of the heart will be described
in accordance with an embodiment of the present invention. It
should be appreciated that the representation of gutter catheter
704 within a left ventricle 720 has not been drawn to scale, for
ease of illustration and ease of discussion. For instance, the
distance between a wall 724 of left ventricle 720 and a mitral
valve 728 has been exaggerated. In addition, it should also be
appreciated that the positioning of delivery tube 604 and, hence,
J-catheter 608 and gutter catheter 704 within aortic valve 732 may
vary.
[0064] Gutter catheter 704 protrudes through tip 626 of J-catheter
608, and, through steering, essentially forms an arc shape similar
to that of mitral valve 728 along the contour of a wall 724 of left
ventricle 720 just beneath mitral valve 728, i.e., along the gutter
of left ventricle 720. Wall 724 of left ventricle 720 is relatively
smooth just beneath mitral valve 728, i.e., generally does not
include trabeculae. Hence, inserting catheter assembly 702 through
an aortic valve 732 into an upper portion left ventricle 720 allows
gutter catheter 704 to be navigated within left ventricle 720 along
wall 724 substantially without being obstructed by trabeculae or
cordae tendonae.
[0065] Gutter catheter 704 generally includes an opening or lumen
(not shown) that is sized to accommodate a guide wire through which
a guide wire may be inserted. The opening may be located along the
central axis of gutter catheter 704, i.e., central axis 730 as
shown in FIG. 7a. Delivering a guide wire through gutter catheter
704 enables the guide wire to effectively follow the contour of
wall 724. In general, the guide wire may include an anchoring tip
which enables the guide wire to be substantially anchored against
wall 724. FIG. 8 is a diagrammatic top-view cut-away representation
of a left side of a heart in which a guide wire has been positioned
in accordance with an embodiment of the present invention. It
should be appreciated that the representation of the left side of a
heart in FIG. 8 has not been drawn to scale, and that various
features have been exaggerated for ease of discussion. A guide wire
802 is positioned along wall 724 of left ventricle 720. Once guide
wire 802 is inserted through gutter catheter 704 of FIGS. 7a-7c,
and anchored against wall 724 using an anchoring tip 806, gutter
catheter 704, along with J-catheter 708, are withdrawn from the
body of the patient. It should be appreciated that delivery tube
604 typically remains positioned within the aorta after guide wire
802 is anchored to wall 724.
[0066] Guide wire 802, which may be formed from a material such as
stainless steel or a shape memory material, is generally anchored
such that guide wire 802 effectively passes along a large portion
of wall 724. Typically, guide wire 802 serves as a track over which
an implant may be positioned. With reference to FIG. 9a, one
embodiment of an implant will be described in accordance the
present invention. A section 904 of an implant includes an opening
908 therethrough which is arranged to fit over a guide wire, i.e.,
guide wire 802 of FIG. 8. In general, an implant is sized to be
inserted through a femoral artery, an aorta, and an aortic valve.
Section 904 includes a biocompatible structure 912 over which a
biocompatible woven mesh 916 is placed. Mesh 916 enables mitral
valve tissue regrowth to occur in and around mesh 916 once the
implant is positioned under the mitral valve. While structure 912
may take a variety of different forms, in one embodiment, structure
may be formed as an open spring element which may effectively be
shortened or collapsed onto itself, e.g., when tension is applied
to an overall implant as will be described below with respect to
FIGS. 11a and 11b.
[0067] FIG. 9b is a cut-away top-view representation of a left side
of a heart in which an implant has been inserted over a guide wire
in accordance with an embodiment of the present invention. It
should be understood that the relative dimensions of features of
the portion of the heart shown in FIG. 9b are not to scale, and
some dimensions have been exaggerated for purposes of discussion.
An implant 924 is positioned over guide wire 802 such that implant
924 substantially follows the curved contour of mitral valve 728
and, hence, fibrous tissue 970 around mitral valve 728. That is,
implant 924 is shaped approximately like a horseshoe. Guide wire
802 effectively supports implant 924 to position implant 924
substantially below mitral valve 728 in left ventricle 720.
[0068] As discussed above with respect to FIG. 5, implant 924 may
be coupled to a balloon or balloons which may be inflated to
effectively push implant 924 up against a bottom side of mitral
valve 728. With reference to FIG. 9c, the positioning of implant
924 against the bottom side of mitral valve 728 will be described
in accordance with an embodiment of the present invention. FIG. 9c
is a diagrammatic cross-sectional side view representation of a
left side of a heart. A balloon 960, which is generally coupled to
implant 924, may be inflated once implant 924 is positioned over
guide wire 802. Balloon 960, once inflated, substantially fills
space in left ventricle 720 between mitral valve 728 and a
papillary muscle 964. Inflating balloon 960 enables the pressure
within balloon 960 to effectively force implant 924 against fibrous
tissue 970 of the fibrous ring around mitral valve 728. In one
embodiment, balloon 960 is formed from an elastomeric material.
[0069] Once implant 924 is suitably positioned, a T-bar delivery
catheter may be inserted through implant 924, as mentioned above
with respect to FIG. 5. Although a T-bar delivery catheter is
described as providing T-bars which are suitable for coupling
implant 924 to fibrous tissue 970 associated with the fibrous ring
around mitral valve 728, it should be understood that other methods
may be used to couple implant 924 to tissue. Substantially any
mechanism or device which may reliably hold tissue may be used.
Suitable devices include, but are not limited to, anvil
arrangements, staples, clips, barbs, and sutures.
[0070] Referring next to FIG. 10, one embodiment of a T-bar
delivery catheter will be described in accordance with an
embodiment of the present invention. A T-bar delivery catheter 1004
may be positioned over guide wire 802 and within implant 924. It
should be appreciated that T-bar delivery catheter 1004 and implant
924 have not been drawn to scale. Within delivery catheter 1004 is
a wire 1008 which carries a T-bar 1012. T-bar 1012 is coupled to an
extension 1016 which may be used to effectively tie off T-bar 1012
such that T-bar 1012 holds implant 924 against fibrous tissue 970
around the mitral valve. Typically, a pointed or sharpened end 1020
of wire 1008 penetrates both implant 924 and fibrous tissue 970.
Once end 1020 and T-bar 1012 are both located above fibrous tissue
970, wire 1008 may be retracted, while T-bar 1012 remains above
fibrous tissue 970, i.e., on an atrial side of fibrous tissue 970.
Retracting wire 1008 and, in one embodiment, delivery catheter
1004, entirely out of a patient enables an additional T-bar to be
loaded onto wire 1008. Once an additional T-bar is positioned on
wire 1008, wire 1008 may be reinserted into delivery catheter 1004,
and delivery catheter 1004 may be used to enable another location
along implant 924 to be essentially attached to fibrous tissue
970.
[0071] In general, the number of T-bars 1012 which may be used to
create connections between implant 924 and fibrous tissue 970 may
vary widely. By way of example, the use of approximately six or
eight T-bars 1012 may be suitable, although fewer or more T-bars
1012 may be used as necessary. After all T-bars 1012 are in place
with respect to implant 924, T-bars 1012 may be tightened by tying
off extensions 1016 associated with T-bars 1012.
[0072] While T-bars 1012 create relatively intimate contact between
implant 924 and fibrous tissue 970, in order to effectively shorten
implant 924, i.e., to provide treatment or therapy using implant
924, implant 924 is typically tensioned. That is, the size of
mitral valve 728 may be reduced by tensioning implant 924. With
reference to FIGS. 11a and 11b, one method of providing tension to
an implant will be described in accordance with an embodiment of
the present invention. An implant 1124 is positioned under a mitral
valve 1128, i.e., in a left ventricle of a heart, and is held
against mitral valve 1128 using coupling devices 1112 that
effectively attach implant 1124 to fibrous tissue 1170. In the
described embodiment, coupling devices 1112 are T-bars, although it
should be understood that other coupling devices, e.g., staples or
barbs, may be used in lieu of T-bars.
[0073] In order to reduce the size of mitral valve 1128, which is
stretched such that a gap 1130 is evident between a posterior
leaflet 1132 and an anterior leaflet 1134, a tensioning element
1140 which is inserted within implant 1124 may be tensioned to
shorten an arc length of implant 1124. Generally, tensioning
element 1140 may be inserted within implant 1134 using a catheter
after implant 1134 is inserted into the left ventricle.
Alternatively, tensioning element 1140 may be preloaded in implant
1134. As shown, tensioning element 1140 is a string which may be
pulled and ultimately tied off to effectively reduce the arc length
associated with the curved outer edge of mitral valve 1128. Pulling
on and tying off tensioning element 1140 may be achieved through
the use of a catheter 1150 inserted within implant 1134.
[0074] When tension element 1140 is tensioned, implant 1124
effectively collapses onto itself, or is shortened. As previously
mentioned, implant 1124 may be formed from a spring-like structure
that is covered by a mesh. The spring-like structure is an
elongated body may be collapsed onto itself or shortened when
tension is applied. Hence, as shown in FIG. 11b, the arc length
associated with mitral valve 1128 may be reduced, e.g., by a
two-to-one ratio. Reducing the arc length associated with mitral
valve 1128 allows gap 1130 to be greatly reduced. In one
embodiment, gap 1130 effectively disappears such that there is no
leakage of mitral valve 1128.
[0075] In one embodiment, implant 1124 is arranged to bend and to
collapse onto itself such that a radius of curvature associated
with implant 1124 may vary. That is, applying tension to implant
1124 allows the radius of curvature of implant 1124 to be reduced.
As implant 1124 is coupled to fibrous tissue 1170 in proximity to
mitral valve 1134, when the radius of curvature of implant 1124 is
reduced, the size of mitral valve 1134 is also reduced.
[0076] It should be appreciated that the configuration of
tensioning element 1140 be different than shown herein. While
tensioning element 1140 may be a string or a similar element which
may be tied off, tensioning element 1140 may also be substantially
any element on which tension may be applied by pulling. Another
particularly suitable tension element is a cable wrap or "zip tie,"
which is generally an element that may be looped onto itself and
then tightened by pulling, e.g., through the use of a catheter such
as catheter 1150 of FIG. 11a. Releasing such an element after
pulling generally does not significantly alter the tension
associated with the element.
[0077] Tensioning element 1140, in cooperation with an adjustable,
or collapsible, implant 1124 allows implant 1124 to be continually
adjusted as needed. By way of example, if a patient requires a
readjustment of implant 1124 at some point after the initial
catheter-based annuloplasty, the patient may undergo a relatively
simple catheter-based procedure designed to alter the tension in
implant 1124. Further, the need to select an implant 1124 for use
based upon the size of a particular implant 1124 may be reduced, as
an implant 1124 of a single size may be adjusted when already
implanted to properly reduce the size of a stretched mitral valve
1128.
[0078] Once implant 1124 is properly adjusted, a patient may be
placed on anticoagulant therapy until mitral tissue has begun to
successfully grow around and into implant 1124. When tissue growth
has reached a desired level, the new tissue may then effectively
support implant 1124, and the patient may generally cease
anticoagulant therapy. As catheter-based annuloplasty is not an
open surgery and is considered to be relatively non-invasive, the
recovery time from catheter-based annuloplasty is relatively short
when compared to the recovery time required by conventional
surgical annuloplasty procedures.
[0079] With reference to FIG. 12, the performance of an
annuloplasty procedure using a catheter-based system will be
described in accordance with an embodiment of the present
invention. Once a patient is prepared, e.g., sedated, an
annuloplasty procedure 504 may begin with the insertion of a
delivery tube and a J-catheter into the left ventricle of the heart
of the patient. The delivery tube and the J-catheter may be
inserted into the body of the patient through the femoral artery,
and threaded through the femoral artery and the aorta into the left
ventricle of the heart. Generally, the J-catheter is positioned
within the delivery tube. One embodiment of the delivery tube and a
J-catheter were described above with respect to FIGS. 6a and 6b. As
will be appreciated by those skilled in the art, the delivery tube
and the J-catheter are typically each threaded through the aortic
valve to reach the left ventricle.
[0080] Once the delivery tube and the J-catheter are positioned
within the left ventricle, a gutter catheter may be extended
through the J-catheter in step 512. As was discussed above with
reference to FIGS. 7a-c, the gutter catheter is arranged to
effectively run against a gutter of the wall of the left ventricle
substantially immediately under the mitral valve. Specifically, the
gutter catheter may be positioned in the space in the left
ventricle between the mitral valve and the musculi papillares, or
papillary muscles. The gutter catheter often has a tip that is
steerable and flexible. In one embodiment, the tip of the gutter
catheter may be coupled to an inflatable balloon. The J-catheter
serves, among other purposes, the purpose of allowing the gutter
catheter to be initially oriented in a proper direction such that
the gutter catheter may be positioned along the wall of the left
ventricle.
[0081] In step 516, a guide wire with an anchoring feature may be
delivered through the gutter catheter, e.g., through a lumen or
opening in the gutter catheter. The guide wire is delivered through
the gutter catheter such that it follows the contour of the gutter
catheter against the wall of the left ventricle. After the guide
wire is delivered, the anchoring feature of the guide wire is
anchored on the wall of the left ventricle in step 520. Anchoring
the guide wire, or otherwise implanting the guide wire, on the wall
of the left ventricle enables the guide wire to maintain its
position within the left ventricle.
[0082] The J-catheter and the gutter catheter are pulled out of the
left ventricle through the femoral artery in step 524, leaving the
guide wire anchored within the left ventricle, as was discussed
above with respect to FIG. 8. Once the J-catheter and the gutter
catheter are removed from the left ventricle, an implant which may
be coupled to a substantially deflated balloon is inserted into the
left ventricle using the guide wire as a guide track in step 528.
In other words, an implant that is intended to be coupled to the
mitral valve is positioned in the left ventricle under the mitral
valve, i.e., on a ventricular side of the mitral valve. One
suitable implant was described above with respect to FIG. 9a. In
one embodiment, the implant may be inserted into the left ventricle
using a catheter which may be retracted once the implant is
positioned under the mitral valve in contact with the fibrous
tissue around the mitral valve.
[0083] After the implant and the balloon are inserted in the left
ventricle, the balloon is inflated in step 532. Inflating the
elastomeric balloon at a relatively modest pressure using, for
example, an air supply coupled to the balloon through the implant,
serves to cause the implant to be pressed up against the fibrous
tissue around the mitral valve. Generally, the inflated balloon
substantially occupies the space between the mitral valve and the
papillary muscles. In one embodiment, more than one balloon may be
used to position the implant against the fibrous tissue around the
bottom of the mitral valve.
[0084] A T-bar delivery catheter is inserted through the implant in
step 536, once the balloon is inflated in step 532. The T-bar
delivery catheter effectively delivers T-bars, or similar
mechanisms, which are arranged to attach or otherwise couple the
implant to an annulus of the mitral valve,e.g., the fibrous tissue
of the skeleton around the mitral valve. In step 540, connections
are created between the implant and substantially any suitable
tissue near the mitral valve to effectively attach the implant to
the tissue. The connections may be created by extending sharpened
wires which carry elements such as T-bars through the implant and
the tissue, then retracting the sharpened wires, and locking the
T-bars in place, as discussed above with respect to FIG. 10.
[0085] Once a desired number of connections, e.g., six connections,
are made between the implant and the tissue, then the balloon may
be deflated and removed from the left ventricle in step 548. It
should be understood that since the implant is effectively
connected to tissue around the mitral valve, deflating the balloon
does not cause the position of the implant to be significantly
moved. After the balloon is deflated, the T-bar delivery catheter
is removed from the left ventricle in step 522. In step 556, the
guide wire may be removed. The implant is then typically shortened
in step 558, as for example by providing tension to the implant. As
will be appreciated by those skilled in the art, shortening the
implant involves contracting the mitral valve or, more
specifically, the posterior leaflet of the mitral valve. Although
the implant may be shortened in substantially any suitable manner,
in one embodiment, the implant may be shortened by tightening a
string or a cord associated with the implant to effectively reduce
the arc length associated with the implant, e.g., by a two-to-one
ratio. Once the implant is successfully shortened, the delivery
tube may be removed in step 560. After the delivery tube is
removed, the annuloplasty procedure is completed.
[0086] It should be appreciated that implanting an implant in
tissue near the mitral valve, then shortening the implant, is just
one method of treating mitral valve leakage in a minimally invasive
manner using a catheter-based system. Another method, which will be
described below with respect to FIGS. 13a and 13b, involves
accessing the mitral valve through the aorta and the left
ventricle, and implanting a clip element which serves to
effectively pinch together the anterior leaflet and the posterior
leaflet of the mitral valve to reduce leakage. FIG. 13a is a
schematic cut-away representation of a left ventricle of the heart
in which a catheter that is suitable for use in accessing a mitral
valve in accordance with a second embodiment of the present
invention is positioned. FIG. 13b is a cross-sectional
representation of the left ventricle and the catheter of FIG. 13a.
A catheter 1304 is inserted into a left ventricle 1314 through an
aortic valve 13 10. Catheter 1304, which may be steerable and
flexible, has a curved orientation such that catheter 1304 may pass
between cordae tendonae 1326 that are coupled to papillary muscles
1322 and mitral valve 1340. That is, catheter 1304 is shaped to
pass through a plane defined by papillary muscles 1322, as well as
cordae tendonae 1326, to reach a posterior leaflet "side" of mitral
valve 1340.
[0087] As shown, catheter 1304 does not follow the contour of a
wall 1318 of left ventricle 1314, and is still positioned such that
a portion of catheter 1304 is positioned in a region of left
ventricle 1314 between mitral valve 1340, cordae tendonae 1326,
papillary muscles 1322, and wall 1318. Hence, catheter 1304 is able
to directly access a posterior leaflet of mitral valve 1340
substantially directly. A catheter 1304 which, in one embodiment,
accesses a gutter portion of left ventricle 1314 may be easier to
fabricate and to actively control than a catheter assembly which
includes a J-catheter and a gutter catheter, e.g., J-catheter 608
and gutter catheter 704 of FIG. 7a, as catheter 1304 generally does
not need to be manipulated with many direction changes. Instead,
catheter 1304 may be formed to include either a curved end portion,
as shown in FIG. 13b, or a v-shaped end portion which both enable
an end portion of catheter 1304 to access the portion of left
ventricle 1314 that is positioned substantially immediately under
mitral valve 1340.
[0088] A tip portion of catheter 1304 may be directed against
mitral valve 1340, thereby facilitating the ability to place a
tissue anchor or clip element which may act to pinch an anterior
leaflet against a posterior leaflet. FIG. 13c is a schematic
representation of a clip element positioned with respect to a
posterior leaflet and an anterior leaflet of a mitral valve in
accordance with a second embodiment of the present invention. It
should be appreciated that the elements in FIG. 13c have not be
drawn to scale for purposes of discussion. A clip 1380, which may
be formed from a material such as steel, may be coupled to an
anterior leaflet 1362 and a posterior leaflet 1366 of a mitral
valve using catheter 1304 of FIGS. 13a and 13b. Clip 1380, which
passes between cordae tendonae 1326 associated with anterior
leaflet 1362 and cordae tendonae 1326 associated with posterior
leaflet 1366, may be coupled to anterior leaflet 1362 and posterior
leaflet 1366 using, for example, T-bar arrangements 1390.
[0089] By pinching together anterior leaflet 1362 and posterior
leaflet 1366, the leakage through a gap (not shown) between
anterior leaflet 1362 and posterior leaflet 1366 may be reduced.
While the presence of clip 1380 may result in a patient having to
undergo anticoagulant therapies, the placement of clip 1380 in lieu
of an implant such as implant 924 of FIG. 9b may minimize the
amount of time associated with a leakage correction process.
[0090] Although only a few embodiments of the present invention
have been described, it should be understood that the present
invention may be embodied in many other specific forms without
departing from the spirit or the scope of the present invention. By
way of example, methods of introducing an implant into the left
ventricle to correct for mitral valve leakage, or mitral valve
insufficiency, may be applied to introducing implants which correct
for leakage in other valves. For instance, the above-described
procedure may be adapted for use in repair a leaking valve
associated with a right ventricle.
[0091] While connecting an implant to fibrous tissue associated
with the mitral valve of the heart has generally been described,
the implant may be connected to other types of tissue which are
near, around, in proximity to, or include the mitral valve. Other
tissues to which an implant may be connected include tissues
associated with the myocardium, or tissues associated with the wall
of the left ventricle. In one embodiment, the implant may be
substantially directly connected to the leaflets of the mitral
valve.
[0092] In general, methods of accessing a left ventricle through
the aorta may be applied to procedures other than annuloplasty. The
left ventricle may be accessed to perform mapping or ablation
therapies, or to stabilize a patient suffering from an acute valve
failure, e.g., by filling space in the left ventricle by inflating
a balloon. Also, a balloon, either steady state or pulsatile, may
be used to increase the ejection fraction associated with the left
ventricle. The left ventricle may also be accessed in order to
access the left atrium through the mitral valve. Specifically, the
smooth portion of the left ventricle, e.g., the gutter, may be
accessed en route to accessing the left atrium. It should be
appreciated that accessing the gutter may be used in conjunction
with access routes via other channels to the heart such as a
coronary sinus and a transceptal approach to the left atrium.
[0093] While a balloon may be inflated within a left ventricle such
that the balloon is effectively trapped under the posterior leaflet
of a mitral valve to treat sudden heart failure. The balloon may
remain positioned in the left ventricle until surgery is performed
on the heart, at which time the balloon may be removed. In one
embodiment, such a balloon may be arranged to be filled with blood
that clots off, thereby enabling the balloon to become what is
effectively a permanent structure in the left ventricle that
reduces mitral regurgitation.
[0094] Access to the left ventricle may also facilitate the use of
a camera within left ventricle. For example, a camera may be fed
into the left ventricle on the tip of a catheter-like device to
enable the interior of the left ventricle to be viewed to identify
any anomalies which may be present in the left ventricle. It should
be appreciated that such a camera may also be passed into the
coronary sinus.
[0095] Rather than implanting an implant to correct for mitral
valve insufficiency using a catheter-based approach, a series of
local plications to the mitral valve may be used to achieve
annuloplasty. By way of example, a catheter or other device that is
suitable for creating local plications may be located along the
wall of a left ventricle beneath the mitral valve. Local plications
may be created by elements which engage fibrous tissue and close
upon themselves such that tissue is engaged. Alternatively, a
one-way tensioning device may be used to effectively pull in on the
local plications, e.g., elements, such that the arc length of the
mitral valve is effectively reduced.
[0096] Local plications may generally be created through the use of
staple elements which engage each other once they penetrate the
fibrous tissue, or hook-like elements. It should be appreciated,
however, that in other embodiments, suture type materials may be
used to create local plications.
[0097] While an implant which may effectively collapse onto itself,
e.g., be shortened, when tension is applied is suitable for use in
a catheter-based annuloplasty as described above, it should be
appreciated that such an implant is suitable for use in a variety
of different annuloplasty procedures. For instance, the implant may
be used in a conventional, surgical annuloplasty procedure since
its use may enable a surgeon to continuously adjust the amount by
which the arc length of a mitral valve may be reduced.
[0098] An implant has generally been described as having a shape
which is similar to that of a horseshoe ring. Implants of other
shapes may generally be implanted within a heart to correct for
mitral valve insufficiency. By way of example, an implant which has
a curved shape that does not follow substantially the entire arc
length of a mitral valve may be implanted without departing from
the spirit or the scope of the present invention. Such an implant
may generally cover a larger area than would be covered by a local
plication.
[0099] It should be understood that although a guide wire has been
described as including an anchoring tip to anchor the guide wire to
a wall of the left ventricle, a guide wire may be anchored with
respect to the left ventricle in substantially any suitable manner.
By way of example, a guide wire may include an anchoring feature
which is located away from the tip of the guide wire. In addition,
a guide wire may more generally be any suitable guiding element
which is configured to facilitate the positioning of an
implant.
[0100] An elastomeric balloon has been described as being suitable
for use in effectively forcing an implant against a surface to
which the implant is to be connected. In lieu of an elastomeric
balloon, substantially an expanding structure may be used to push
the implant against a surface. By way of example, an expanding
metal structure which is expandable from a closed position into an
open position may be used to provide pressure or force on an
implant.
[0101] While access to the gutter of the left ventricle has been
described as being associated with a minimally invasive catheter
annuloplasty procedure, it should be understood that the gutter of
the left ventricle may also be accessed, e.g., for an annuloplasty
procedure, as a part of a surgical procedure. For instance, the
aorta of a heart may be accessed through an open chest surgical
procedure before a catheter is inserted into the aorta to reach the
left ventricle. Alternatively, an implant may be introduced on a
ventricular side of a mitral valve through a ventricular wall which
is accessed during an open chest surgical procedure.
[0102] The steps associated with performing a catheter-based
annuloplasty may be widely varied. Steps may generally be added,
removed, reordered, and altered without departing from the spirit
or the scope of the present invention. Therefore, the present
examples are to be considered as illustrative and not restrictive,
and the invention is not to be limited to the details given herein,
but may be modified within the scope of the appended claims.
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