U.S. patent application number 12/850531 was filed with the patent office on 2011-08-25 for devices and methods for cardiac annulus stabilization and treatment.
This patent application is currently assigned to Guided Delivery Systems, Inc.. Invention is credited to Niel F. STARKSEN.
Application Number | 20110207996 12/850531 |
Document ID | / |
Family ID | 34226432 |
Filed Date | 2011-08-25 |
United States Patent
Application |
20110207996 |
Kind Code |
A1 |
STARKSEN; Niel F. |
August 25, 2011 |
DEVICES AND METHODS FOR CARDIAC ANNULUS STABILIZATION AND
TREATMENT
Abstract
Devices and methods generally provide enhanced stabilization,
exposure and/or treatment of a cardiac valve annulus. Methods
generally involve introducing a stabilizing member beneath one or
more leaflets of a heart valve to engage the annulus at an
intersection between the leaflets and the interior ventricular wall
of the heart. Force is then applied to the stabilizing member to
stabilize and/or expose the valve annulus. In some embodiments, the
stabilizing member may include a series of hydraulically driven
tethered anchors, such as hooks or clips, for engaging and cinching
valve annulus tissue to decrease the diameter of a regurgitant
valve. Alternatively, other treatments may be delivered by a
stabilizing member, such as radiofrequency energy, drugs, bulking
agents or shape memory stents. A second stabilizing member may also
be introduced above the leaflets for further stabilization.
Inventors: |
STARKSEN; Niel F.; (Los
Altos Hills, CA) |
Assignee: |
Guided Delivery Systems,
Inc.
Santa Clara
CA
|
Family ID: |
34226432 |
Appl. No.: |
12/850531 |
Filed: |
August 4, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12132375 |
Jun 3, 2008 |
7922762 |
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12850531 |
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10656797 |
Sep 4, 2003 |
7753922 |
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12132375 |
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Current U.S.
Class: |
600/37 |
Current CPC
Class: |
A61F 2/2445 20130101;
A61F 2/2466 20130101; A61F 2/2451 20130101 |
Class at
Publication: |
600/37 |
International
Class: |
A61B 17/00 20060101
A61B017/00 |
Claims
1. A method for stabilizing a valve annulus of a heart for
performing a procedure on the valve annulus, the method comprising:
introducing at least a first stabilizing member beneath one or more
leaflets of a valve of the heart to engage the annulus at an
intersection between at least one leaflet and an interior
ventricular wall of the heart; and applying force to the first
stabilizing member to stabilize the valve annulus.
2. A method as in claim 1, wherein introducing comprises passing
the member beneath at least the posterior leaflet of the mitral
valve of the heart.
3. A method as in claim 1, wherein applying force to the first
stabilizing member exposes the valve annulus from surrounding
tissue of the heart.
4. A method as in claim 1, wherein introducing comprises advancing
an elongate catheter carrying the first stabilizing member through
vasculature of a patient to the heart, wherein the first
stabilizing member is adapted to change between a flexible
configuration for introduction through the vasculature and a curved
configuration to conform to the annulus.
5. A method as in claim 4, further comprising changing the shape of
the first stabilizing member to conform to the annulus.
6. A method as in claim 5, wherein changing the shape of the first
stabilizing member comprises articulating the stabilizing member in
at least two directions.
7. A method as in claim 5, wherein changing the shape of the first
stabilizing member comprises applying tension to at least a first
tensioning cord to cause a first bend in the stabilizing
member.
8. A method as in claim 7, wherein changing the shape further
comprises applying tension to at least a second tensioning cord to
cause a second bend in the stabilizing member.
9. A method as in claim 8, wherein the first bend comprises
approximately a C-shaped bend to conform the stabilizing member to
the annulus, and the second bend comprises an upwardly directed
bend.
10. A method as in claim 5, wherein changing the shape of the first
stabilizing member comprises introducing a fluid into a
shape-memory stabilizing member.
11. A method as in claim 5, further comprising locking the shape of
the first stabilizing member.
12. A method as in claim 1, wherein applying force to the first
stabilizing member comprises applying upwardly directed force in a
direction from the ventricles toward the atria of the heart.
13. A method as in claim 1, wherein stabilizing further comprises
introducing at least a second stabilizing member over the valve
leaflets.
14. A method as in claim 13, further comprising moving the second
stabilizing member toward the first stabilizing member to further
stabilize the valve annulus.
15. A method for stabilizing a valve annulus of a heart for
performing a procedure on the valve annulus, the method comprising:
advancing a flexible, elongate stabilizing catheter through
vasculature of a patient to the heart; introducing at least a first
stabilizing member of the stabilizing catheter beneath one or more
leaflets of a valve of the heart to engage the annulus at an
intersection between at least one leaflet and an interior
ventricular wall of the heart; changing the shape of the
stabilizing member to conform to the annulus; and applying force to
the stabilizing member to stabilize the valve annulus.
16. (canceled)
17. A method as in claim 15, wherein changing the shape of the
first stabilizing member comprises applying tension to at least a
first tensioning cord to cause a first bend in the stabilizing
member.
18. A method as in claim 17, wherein changing the shape further
comprises applying tension to at least a second tensioning cord to
cause a second bend in the stabilizing member.
19. A method as in claim 18, wherein the first bend comprises
approximately a C-shaped bend to conform the stabilizing member to
the annulus, and the second bend comprises an upwardly directed
bend.
20. (canceled)
21. A method as in claim 15, further comprising locking the shape
of the first stabilizing member.
22. (canceled)
23. A method as in claim 15, wherein stabilizing further comprises
introducing at least a second stabilizing member over the valve
leaflets.
24-57. (canceled)
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is related to, and contains subject
matter in common with, U.S. patent application Ser. No. 10/461,043
(Attorney Docket No. 16886-000310), filed on Jun. 13, 2003, which
is assigned to the assignees of the present invention, and which is
hereby incorporated fully by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to medical devices
and methods. More particularly, the invention relates to devices
and methods for enhancing cardiovascular valve repair, especially
the repair of heart valves such as the mitral and tricuspid
valves.
[0004] In recent years, many advances have been made to reduce the
invasiveness of cardiac surgery. In an attempt to avoid open,
stopped-heart procedures, which may be accompanied by high patient
morbidity and mortality, many devices and methods have been
developed for operating on a heart through smaller incisions,
operating on a beating heart, and even performing cardiac
procedures via transvascular access. Different types of cardiac
procedures, such as cardiac ablation techniques for treating atrial
fibrillation, stenting procedures for atherosclerosis, and valve
repair procedures for treating conditions such as mitral valve
regurgitation have experienced significant technological advances.
In implementing many minimally invasive cardiac surgery techniques,
especially beating-heart techniques, one of the most significant
challenges is exposing and stabilizing a portion of cardiac tissue
to be operated upon. Another challenge, once exposure and stability
are achieved, is to effectively deploy a given treatment into or on
the target cardiac tissue using minimally invasive devices.
[0005] One type of cardiac surgery which may benefit from less
invasive techniques is heart valve repair. Traditional treatment of
heart valve stenosis or regurgitation, such as mitral or tricuspid
regurgitation, typically involves an open-heart surgical procedure
to replace or repair the valve. Valve repair procedures typically
involve annuloplasty, a set of techniques designed to restore the
valve annulus shape and strengthen the annulus. Conventional
annuloplasty surgery generally requires a large incision into the
thorax of the patient (a thoracotomy), and sometimes a median
sternotomy (cutting through the middle of the sternum). These open
heart, open chest procedures routinely involve placing the patient
on a cardiopulmonary bypass machine for sustained periods so that
the patient's heart and lungs can be artificially stopped during
the procedure. Finally, valve repair and replacement procedures are
typically technically challenging and require a relatively large
incision through the wall of the heart to access the valve.
[0006] Due to the highly invasive nature of open heart valve repair
or replacement, many patients, such as elderly patients, patients
having recently undergone other surgical procedures, patients with
comorbid medical conditions, children, late-stage heart failure
patients, and the like, are often considered too high-risk to
undergo heart valve surgery and are relegated to progressive
deterioration and cardiac enlargement. Often, such patients have no
feasible alternative treatments for their heart valve
conditions.
[0007] To obviate this situation, a number of devices and methods
for repairing cardiac valves in a less invasive manner have been
described. Some devices provide for heart valve repair through
minimally invasive incisions or intravascularly, while others
improve upon open heart surgical procedures on beating hearts,
stopped hearts or both. For example, several improved devices and
methods for heart valve repair are described in one or more patent
applications filed by the inventors of the present invention and
assigned to the assignee of the present invention. For further
description of such devices and methods, reference may be made to
U.S. patent application Ser. No. 10/461,043 (Attorney Docket No.
16886-000310), filed on Jun. 13, 2003, previously incorporated by
reference.
[0008] As mentioned above, some of the difficulties in performing
minimally invasive intracardiac surgery include exposing and
stabilizing an area of cardiac tissue to be operated upon and
effectively operating on that tissue using minimally invasive
instruments. Sufficient exposure is essential for allowing the
physician to locate and perform a procedure on the targeted cardiac
tissue. Stabilization further facilitates an intracardiac
procedure, especially in a beating heart. In minimally invasive,
beating heart surgery on a cardiac valve annulus, exposure and
stabilization are especially challenging, due to rapid movement of
the annulus and the heart, the small size of the annulus, and the
blood-filled surgical field. While a cardiac valve may be
visualized via transesophageal echocardiogram (TEE), it is much
more difficult to locate the annulus itself, as it is basically a
small band of fibrous tissue. Exposure of the annulus is essential,
however, since annular tissue is far stronger than surrounding
valve leaflet and heart wall tissue, and repair procedures
performed on a valve annulus will be much more effective than those
performed on other tissue adjacent the annulus. Even after a valve
annulus is exposed and stabilized, it may still be challenging to
effectively and efficiently operate on the annulus to repair the
valve, using minimally invasive devices.
[0009] Many minimally invasive or "less invasive" surgical
procedures other than heart valve repair would also benefit from
improved exposure and/or stabilization. For example, improved
exposure and stabilization could facilitate other cardiac
procedures, such as accessing the coronary sinus for placement of
an implantable device or for performing a procedure, placing
pacemaker leads in one or more areas of the heart, ablation
procedures such as ablation around the pulmonary veins to treat
atrial fibrillation, atrial-septal defect repair procedures, and
the like. Improved stabilization and exposure could also be used to
enhance non-cardiac procedures such cinching or otherwise treating
a bladder, stomach, gastroesophageal junction, vascular structure,
gall bladder or the like.
[0010] Therefore, it would be beneficial to have devices and
methods for enhancing exposure and/or stabilization in
transvascular, minimally invasive and other "less invasive"
surgical procedures, such as heart valve repair and other cardiac
procedures. Ideally, for example, such devices and method could be
used for exposing and stabilizing a cardiac valve annulus for
performing a valve repair procedure. Ideally, such devices and
methods could be used in minimally invasive or "less invasive"
beating heart procedures performed via a variety of access routes,
such as transvascular or transthoracic. Also ideally, some devices
might be used for exposing a valve annulus, others might expose and
stabilize an annulus, and still others might expose, stabilize and
administer a therapy to an annulus, thus providing a physician with
numerous procedural options. At least some of these objectives will
be met by the present invention.
[0011] 2. Description of the Background Art
[0012] Published U.S. Application 2002/0156526 describes a
catheter-based method for performing annuloplasty. Published U.S.
Application 2002/0042621 describes a heart valve annuloplasty
system with constrictable plication bands which are optionally
attached to a linkage strip. Published U.S. Application
2002/0087169 describes a remote controlled catheter system which
can be used to deliver anchors and a tether for performing an
annuloplasty procedure. Other patent publications of interest
include WO01/26586; US2001/0005787; US2001/0014800; US2002/0013621;
US2002/0029080; US2002/0035361; US2002/0042621; US2002/0095167; and
US2003/0074012. U.S. patents of interest include U.S. Pat. Nos.
4,014,492; 4,042,979; 4,043,504; 4,055,861; 4,700,250; 5,366,479;
5,450,860; 5,571,215; 5,674,279; 5,709,695; 5,752,518; 5,848,969;
5,860,992; 5,904,651; 5,961,539; 5,972,004; 6,165,183; 6,197,017;
6,250,308; 6,260,552; 6,283,993; 6,269,819; 6,312,447; 6,332,893;
and 6,524,338. Publications of interest include De Simone et al.
(1993) Am. J. Cardiol. 73:721-722, and Downing et al. (2001) Heart
Surgery Forum, Abstract 7025.
BRIEF SUMMARY OF THE INVENTION
[0013] Devices and methods of the present invention are generally
used to facilitate transvascular, minimally invasive and other
"less invasive" surgical procedures, by enhancing exposure,
stabilization and/or the like of a tissue or structure upon which a
procedure is to be performed. "Less invasive," for the purposes of
this application, means any procedure that is less invasive than
traditional, large-incision open surgical procedures. Thus, a less
invasive procedure may be an open surgical procedure involving one
or more relatively small incisions, a transvascular percutaneous
procedure, a transvascular procedure via cut-down, a laparoscopic
or other endoscopic procedure, or the hie. Generally, any procedure
in which a goal is to minimize or reduce invasiveness to the
patient may be considered less invasive. Furthermore, although the
terms "less invasive" and "minimally invasive" may sometimes be
used interchangeably in this application, neither these nor terms
used to describe a particular subset of surgical or other
procedures should be interpreted to limit the scope of the
invention. Generally, stabilization/exposure devices and methods of
the invention may be used in performing or enhancing any suitable
procedure.
[0014] As mentioned above, the present application typically
describes devices and methods for stabilization and/or exposure in
the context of heart valve repair, and more specifically mitral
valve repair to treat mitral regurgitation. It should be
emphasized, however, that devices and methods of the invention may
be used in any suitable procedure, both cardiac and non-cardiac.
For example, they may be used in procedures to repair any heart
valve, to repair an atrial-septal defect, to access and possibly
perform a procedure from (or through) the coronary sinus, to place
one or more pacemaker leads, to perform a cardiac ablation
procedure such as ablating around pulmonary veins to treat atrial
fibrillation, and/or the like. In other embodiments, the devices
and methods may be used to enhance a laparoscopic or other
endoscopic procedure on any part of the body, such as the bladder,
stomach, gastroesophageal junction, vasculature, gall bladder, or
the like. Therefore, although the following description typically
focuses on mitral valve and other heart valve repair, such
description should not be interpreted to limit the scope of the
invention as defined by the claims.
[0015] That being said, the present invention generally provides
devices and methods for enhanced stabilization, exposure and/or
treatment of a cardiac valve annulus. Methods generally involve
introducing a stabilizing member beneath one or more leaflets of a
heart valve to engage the ventricular side of the annulus at an
intersection between the leaflets and the interior ventricular wall
of the heart. The stabilizing member will usually be curved or
C-shaped to conform to at least a portion of the ventricular side
of the annulus, and force is applied to the stabilizing member to
engage and stabilize the valve annulus. By "stabilize," it is meant
that the annulus will be at least partially immobilized relative to
the cardiac tissue surrounding the annulus, at least partially
delineated or exposed relative to cardiac tissue surrounding the
annulus, or both. For example, in some instances "stabilization"
may not involve immobilizing annular tissue but may instead involve
moving or positioning annular tissue in such a way to allow
enhanced visualization of that tissue relative to surrounding
tissues.
[0016] As just mentioned, in addition to stabilizing, methods and
apparatus of the present invention may also help expose, position,
or delineate the valve annulus, to enhance the physician's ability
to view and operate on the annular tissue. Some embodiments also
include a second stabilizing member, to be introduced above the
leaflets, allowing a physician to grasp or clamp annular tissue
between the upper and lower stabilizing members for further
stabilization. Various embodiments further provide for treatment of
a valve annulus. For example, either the upper or lower stabilizing
member may include actuators or effectors for performing any one or
more of a variety of interventions. For example, either or both
stabilizing members may be adapted to deliver devices for
constricting or reshaping the valve annulus to treat regurgitation
or other conditions. The devices may comprise anchors, tethered
anchors, rings, or the like for reinforcing or cinching the
annulus. In a specific example, the stabilizing member may be
configured to hydraulically or otherwise deliver a series of
tethered hooks, tethered clips or other tethered anchors or
fasteners for engaging and cinching valve annulus tissue to
decrease the diameter of a regurgitant valve. The stabilizer(s)
will also be adaptable for delivering other therapies, including
applying radiofrequency energy (or other heat sources) to shrink
the collagen tissue in the annulus, delivering bulking agents,
delivering drugs and biological agents such as growth factors,
delivering agents for providing cell dedifferentiation, and/or the
like.
[0017] In most cases, the methods of the present invention will be
performed on a beating heart. Access to the beating heart may be
accomplished by any available technique, including intravascular,
transthoracic, and the like. In addition to beating heart access,
the methods of the present invention may be used for intravascular
stopped heart access as well as stopped heart open chest
procedures.
[0018] In one aspect of the invention, a method for stabilizing a
valve annulus of a heart for performing a procedure on the valve
annulus involves first introducing at least a first stabilizing
member beneath one or more leaflets of a valve of the heart to
engage an intersection between at least one leaflet and the
interior ventricular wall of the heart. Force is then applied to
the first stabilizing member to stabilize the valve annulus.
Usually, the stabilizing member engages the ventricular annulus (in
the case of a mitral valve), and applying force comprises drawing
the stabilizing member upwardly against the annulus to immobilize
the annular tissue relative to the surrounding tissue. When a
second stabilizing member is employed, applying force comprises
applying opposed forces with the "upper and lower" stabilizing
members to further stabilize the annular tissue. Such methods may
be used on any of a number of cardiac or circulatory valves or
other body structures such as valves in body lumens, but in one
embodiment, for example, the first stabilizing member is passed
beneath the posterior leaflet of the mitral valve. In addition to
stabilizing the annular tissue, applying pressure with the
stabilization device may also expose the valve annulus from
surrounding tissue of the heart, for improved visualization and
access by the physician.
[0019] In some embodiments, introducing the device comprises
advancing a flexible, elongate catheter through vasculature of a
patient to the heart, with at least a first stabilizing member
comprising a shape-changing member at a distal end of the flexible
elongate catheter. The catheter may be introduced through the
vasculature with the shape-changing stabilizing member in a
generally straight, flexible configuration. Once it is in place
beneath the leaflet at the intersection between the leaflet and the
interior ventricular wall, the shape of the stabilizing member is
changed to conform to the annulus and usually the shape is "locked"
to provide sufficient stiffness or rigidity to permit the
application of force from the stabilizing member to the annulus.
Shaping and optionally locking the stabilizing member may be
accomplished in any of a number of ways, such as applying tension
to tensioning cord(s), as described in detail below.
[0020] In transthoracic and other embodiments, the stabilizing
member may be pre-shaped, and the method may simply involve
introducing the stabilizing member(s) under and/or over the valve
leaflets. The pre-shaped stabilizing member(s) may be rigid or
formed from a shape memory material such as nitinol, spring
stainless steel, or the like.
[0021] Force applied to the first stabilizing member is often
upwardly directed, though lateral forces are also possible. In
addition to stabilizing with force from below the annulus,
stabilizing may optionally include introducing a second stabilizing
member over the valve leaflets. By moving the second stabilizing
member toward the first stabilizing member, a physician may grip or
clamp all or a portion of the valve annulus.
[0022] In another aspect, a method for performing a procedure on a
stabilized valve annulus includes advancing a flexible, elongate
stabilizing catheter through vasculature of a patient to the heart.
Next, a shape-changing stabilizing member on the catheter is
positioned beneath one or more leaflets of a valve of the heart to
engage the lower or ventricular annulus at an intersection between
at least one leaflet and an interior ventricular wall of the heart.
The shape of the stabilizing member is then changed and optionally
locked to conform to the annulus, and an upward and/or other force
is applied to the stabilizing member to stabilize the valve
annulus.
[0023] In still another aspect of the present invention, a method
for constricting a valve annulus in a beating heart comprises
introducing at least a first stabilizing member beneath one or more
leaflets of a valve of the heart to engage the annulus at an
intersection between at least one leaflet and an interior
ventricular wall of the heart. Force is then applied to the first
stabilizing member to stabilize the valve annulus. A plurality of
individual anchors, such as hooks, clips, barbs, T-tags, rings,
anchors made of resorbable polymers such as polylactic acid or
polyglycolic acid, or the like, may then be placed at
circumferentially spaced-apart locations about at least a portion
of the valve annulus while the valve annulus remains stabilized.
The anchors may then be cinched via a tether to circumferentially
tighten the annulus. Optionally, the method may further include
introducing at least a second stabilizing member over the valve
leaflets and moving the second stabilizing member toward the first
stabilizing member to further stabilize the annulus. In some
embodiments, securing the anchors comprises driving the anchors
from one of the first and second stabilizing members. Driving the
anchors, in turn, may involve inflating an expandable balloon in
one of the members to force the anchors at least partially out of
the member into tissue of the valve annulus. Optionally, securing
the anchors may also involve driving the anchors through tissue of
the valve annulus into a anchor receiving piece coupled with the
other stabilizing member.
[0024] Throughout the present application, the term "anchor" is
frequently used to a device for coupling with a valve annulus or
other bodily structure. For the purposes of this application,
"anchor" means any fastener or other attachment device. Thus, an
anchor may be a hook, such as a curved hook or a straight, barbed
hook, a clip, a T-tag, a ring, an adhesive strip, a shape-memory
fastening device or any other fastener. Furthermore, anchors may be
made of any suitable material. For example, an anchor may be made
of a metal, such as stainless steel, or may alternatively be made
of a bioresorbable material such as polylactate or polyglycolate,
such that over time, after a body structure has repaired, the
anchors may be resorbed. Therefore, although various examples of
anchors are described below and various terms such as "hooks" may
be used to describe fastening devices of the invention, these terms
should not be interpreted to limit the scope of the invention as
defined by the claims.
[0025] In yet another aspect of the invention, a device for
enhancing a surgical procedure on a valve annulus of a heart
includes an elongate body having a proximal end and a distal end
and at least a first stabilizing member at the distal end of the
shaft. Generally, the first stabilizing member is passable under
one or more leaflets of a valve of the heart to engage an
intersection between at least one leaflet and an interior
ventricular wall of the heart. In some embodiments, the elongate
body comprises a rigid shaft. In alternative embodiments, the
elongate body comprises a flexible catheter, so that the first
stabilizing member may be passed into the heart and under the one
or more leaflets via a transvascular approach.
[0026] The first stabilizing member may comprise a shape-changing
portion. By "shape-changing," it is meant that at least a segment
of the stabilizing member may be transitioned between (a) a
straight or flexible configuration (to facilitate introduction) and
(b) a fixed-shape configuration, generally a curved or C-shaped
segment which conforms to the shape of the valve annulus. Such
shape-changing may be accomplished by a variety of mechanical
approaches. In some embodiments, for example, the first stabilizing
member may include a slotted, segmented or sectioned tube coupled
with one or more pull cords. Tension may be applied to one pull
cord to bend the segmented tube into a C-shape, while tension may
be applied to the other cord to bend the tube up, or proximally.
Generally, a segmented tube and two pull cords can be used to shape
a stabilizing member around two bends having any desired
configuration. In another embodiment, a shape-memory material may
be included in the first stabilizing member, and introducing fluid
into the member may cause it to change from a straight
configuration to a C-shape. In some embodiments, the shape-changing
portion may be locked in position to enhance stabilization of the
annulus.
[0027] In some embodiments, the first stabilizing member includes a
semicircular housing, a plurality of tethered anchors disposed
within the housing, and at least one expandable balloon for driving
the plurality of anchors into tissue of the valve annulus. In some
embodiments, the device may include an inflation actuator for
inflating the expandable balloon, a release actuator for releasing
the anchors from the housing, and a cinching actuator for cinching
a tether coupled with the tethered anchors to reduce a diameter of
the valve annulus. The first stabilizing member may be configured
to allowing driving of the plurality of anchors in any suitable
direction or configuration. For example, in some embodiments the
first stabilizing member will be configured for positioning under a
heart valve annulus and for driving anchors upwards (or superiorly)
into or through the annulus. In another embodiment, a stabilizing
member may be configured for positioning above an annulus and for
driving anchors downwards. Alternatively, a stabilizing member may
be positioned outside a heart wall or other structure, with anchors
driven inwardly. And as discussed above, these devices may be used
to perform other cardiac and non-cardiac procedures, such as
anchoring and cinching a gastroesophageal junction, bladder outlet
or other structure.
[0028] As mentioned above, some embodiments also include at least a
second stabilizing member movably coupled with the elongate shaft,
wherein the second stabilizing member may be moved toward the first
stabilizing member to grip and stabilize the valve annulus.
Optionally, such embodiments may also include one or more anchor
receiving pieces coupled with the second stabilizing member for
receiving distal ends of the plurality of anchors driven through
the tissue of the valve annulus. In some embodiments, each of the
first and second stabilizing members comprises a flexible
rigidifying portion. Alternatively, each of the first and second
stabilizing members may comprise a rigid member. Some embodiments
may also include a handle near the proximal end of the shaft for
moving the second stabilizing member toward the first stabilizing
member to grip the valve annulus.
[0029] In alternative embodiments, either the first stabilizing
member, the second stabilizing member or both may include any of a
number of annulus treatment devices. For example, in one embodiment
a stabilizing member may include an energy deliver device, such as
a radiofrequency delivery device, for transmitting energy to a
valve annulus to constrict the annular tissue. In another
embodiment, a stabilizing member may include a mechanical support
member or other deployable device that is couplable with a valve
annulus. For example, a shape memory stent may be coupled with a
stabilizing member such that when the stent is coupled with annular
tissue and deployed, it shrinks longitudinally to reduce the
diameter of the annulus. In other embodiments, multiple such stents
may be used. These and other embodiments are described more fully
below with reference to the drawing figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1 is a cross-sectional view of a heart with a flexible
stabilization device being positioned for stabilizing a valve
annulus, according to one embodiment of the present invention;
[0031] FIGS. 1A and 1B are cross-sectional views of a valve
leaflet, valve annulus, atrial wall and ventricular wall, with a
stabilization device in place for stabilizing and exposing the
annulus, according to one embodiment of the present invention;
[0032] FIG. 2 is a perspective view of a stabilization device
having two stabilization members, according to one embodiment of
the present invention;
[0033] FIG. 3 is a cross-sectional view of a valve leaflet, valve
annulus, atrial wall and ventricular wall, with a stabilization
device in place having upper and lower stabilization members,
according to one embodiment of the present invention;
[0034] FIG. 4 shows a stabilization device as in FIG. 3 with a
tethered clip placed in the valve annulus, according to one
embodiment of the present invention;
[0035] FIG. 5 shows a stabilization device having a balloon-driven
clip applier as its upper stabilizing member, according to one
embodiment of the present invention;
[0036] FIGS. 5A and 5B show a stabilization device having a
balloon-driven hook applier as its upper stabilizing member, and a
method for using same, according to one embodiment of the present
invention;
[0037] FIGS. 5C and 5D show a stabilization device having a
balloon-driven hook applier as its upper stabilizing member, a
lower stabilizing member carrying a hook receiver, and a method for
using same, according to one embodiment of the present
invention;
[0038] FIG. 6 is a perspective view of a balloon-driven hook
applier for applying hooks to a cardiac valve annulus, according to
one embodiment of the present invention;
[0039] FIG. 7 is a close-up view of the device in FIG. 6; and
[0040] FIG. 8 is a perspective view of a balloon-driven hook
applier as in FIGS. 6 and 7, with the balloon expanded and the
hooks deployed, according to one embodiment of the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0041] Devices and methods of the present invention are generally
used to facilitate transvascular, minimally invasive and other
"less invasive" surgical procedures, by enhancing exposure,
stabilization and/or the like of a tissue or structure upon which a
procedure is to be performed. As discussed more fully above, "less
invasive," for the purposes of this application, means any
procedure that is less invasive than traditional, large-incision
open surgical procedures. Thus, a less invasive procedure may be an
open surgical procedure involving one or more relatively small
incisions, a transvascular percutaneous procedure, a transvascular
procedure via cut-down, a laparoscopic or other endoscopic
procedure, or any procedure in which a goal is to minimize or
reduce invasiveness to the patient may be considered less
invasive.
[0042] The present application typically describes devices and
methods for stabilization and/or exposure in the context of heart
valve repair, and more specifically mitral valve repair to treat
mitral regurgitation. Devices and methods of the invention may be
used in any suitable procedure, however, both cardiac and
non-cardiac. For example, they may be used in procedures to repair
any heart valve, to repair an atrial-septal defect, to access and
possibly perform a procedure from (or through) the coronary sinus,
to place one or more pacemaker leads, to perform a cardiac ablation
procedure such as ablating around pulmonary veins to treat atrial
fibrillation, and/or the like. In other embodiments, the devices
and methods may be used to enhance a laparoscopic or other
endoscopic procedure on any part of the body, such as the bladder,
stomach, gastroesophageal junction, vasculature, gall bladder, or
the like. In some embodiments, for example, devices and methods
include coupling multiple tethered anchors to a valve annulus and
cinching the annulus to reduce a diameter of the valve. Similar
devices and methods may be used, alternatively, to close or reduce
the diameter of an atrial-septal defect, a gastroesophageal
junction, or any other suitable body lumen, valve or other
structure. Therefore, although the following description typically
focuses on mitral valve and other heart valve repair, such
description should not be interpreted to limit the scope of the
invention as defined by the claims.
[0043] Devices and methods of the invention generally provide for
enhanced stabilization, exposure and/or treatment of a cardiac
valve annulus. By "stabilize," it is meant that the annulus will be
at least partially immobilized relative to the cardiac tissue
surrounding the annulus, at least partially delineated or exposed
relative to cardiac tissue surrounding the annulus, or both. For
example, in some instances "stabilization" may not involve
immobilizing annular tissue but may instead involve moving or
positioning annular tissue in such a way to allow enhanced
visualization of that tissue relative to surrounding tissues.
Methods generally involve introducing a stabilizing member beneath
one or more leaflets of a heart valve to engage the ventricular
side of the annulus at an intersection between the leaflets and the
interior ventricular wall of the heart. The stabilizing member will
usually be curved or C-shaped to conform to at least a portion of
the ventricular side of the annulus, and force is applied to the
stabilizing member to engage and stabilize the valve annulus.
[0044] In addition to stabilizing, methods and apparatus of the
present invention may also help expose, position, or delineate the
valve annulus, to enhance the physician's ability to view and
operate on the annular tissue. Some embodiments also include a
second stabilizing member, to be introduced above the leaflets,
allowing a physician to grasp or clamp annular tissue between the
upper and lower stabilizing members for further stabilization.
Various embodiments further provide for treatment of a valve
annulus. For example, either the upper or lower stabilizing member
may include actuators or effectors for performing any one or more
of a variety of interventions. For example, either or both
stabilizing members hay be adapted to deliver devices for
constricting or reshaping the valve annulus to treat regurgitation
or other conditions. The devices may comprise anchors, tethered
anchors, rings, or the like for reinforcing or cinching the
annulus. In a specific example, the stabilizing member may be
configured to hydraulically or otherwise deliver a series of
tethered hooks, tethered clips or other tethered anchors or
fasteners for engaging and cinching valve annulus tissue to
decrease the diameter of a regurgitant valve. The stabilizer(s)
will also be adaptable for delivering other therapies, including
applying radiofrequency energy (or other heat sources) to shrink
the collagen tissue in the annulus, delivering bulking agents,
delivering drugs and biological agents such as growth factors.
[0045] In most cases, the methods of the present invention will be
performed on a beating heart. Access to the beating heart may be
accomplished by any available technique, including intravascular,
transthoracic, and the like. In addition to beating heart access,
the methods of the present invention may be used for intravascular
stopped heart access as well as stopped heart open chest
procedures.
[0046] Referring now to FIG. 1, a heart H is shown in cross
section, with a stabilization device 100 introduced within the
heart H. Generally, stabilization device 100 comprises an elongate
body with at least a first stabilizing member 102 at its distal end
for providing stabilization and/or exposure of a heart valve
annulus. In some embodiments, the elongate body comprises a rigid
shaft, while in other embodiments it comprises a flexible catheter,
so that the first stabilizing member may be positioned in the heart
H and wider one or more valve leaflets to engage an valve annulus
via a transvascular approach. Transvascular access may be gained,
for example, through the internal jugular vein (not shown) to the
superior vena cava SVC to the right atrium RA, across the
interatrial septum to the left atrium LA, and then under one or
more mitral valve leaflets MVL to a position within the left
ventricle (LV) under the valve annulus (not shown). Alternatively,
access to the heart may be achieved via the femoral vein and the
inferior vena cava. In other embodiments, access may be gained via
the coronary sinus (not shown) and through the atrial wall into the
left atrium.
[0047] In other embodiments, access to the heart H may be
transthoracic, with the stabilization device being introduced into
the heart via an incision or port on the heart wall. Even open
heart surgical procedures may benefit from methods and devices of
the invention. Furthermore, some embodiments may be used to enhance
procedures on the tricuspid valve annulus, adjacent the tricuspid
valve leaflets TVL, or any other cardiac or vascular valve.
Therefore, although the following description typically focuses on
minimally invasive or less invasive mitral valve repair for
treating mitral regurgitation, the invention is in no way limited
to that use.
[0048] With reference to FIGS. 1A and 1B, a method for using
stabilization device 100 is depicted in a cross-sectional view.
First, as in FIG. 1A, stabilizing member 102 is positioned in a
desired location under a valve leaflet L and adjacent a ventricular
wall VW. The valve annulus generally comprises an area of heart
wall tissue at the junction of the ventricular wall VW and the
atrial wall AW that is relatively fibrous and, thus, significantly
stronger that leaflet tissue and other heart wall tissue.
Stabilizing member 102 may be advanced into position under the
valve annulus by any suitable technique, some of which are
described below in further detail. For example, using a
stabilization device having a flexible elongate body as shown in
FIG. 1, stabilizing member 102 may be passed from the right atrium
RA through the interatrial septum in the area of the foramen ovale
(not shown--behind the aorta A), into the left atrium LA.
Oftentimes, stabilizing member 102 will then naturally travel, upon
further advancement, under the posterior valve leaflet to a
position under the valve annulus VA, as shown in FIG. 1A.
[0049] In some embodiments, stabilizing member 102 includes a
shape-changing portion which enables stabilizing member 102 to
conform to the shape of the valve annulus VA. The catheter may be
introduced through the vasculature with the shape-changing
stabilizing member in a generally straight, flexible configuration.
Once it is in place beneath the leaflet at the intersection between
the leaflet and the interior ventricular wall, the shape of
stabilizing member 102 is changed to conform to the annulus and
usually the shape is "locked" to provide sufficient stiffness or
rigidity to permit the application of force from stabilizing member
102 to the annulus. Shaping and optionally locking stabilizing
member 102 may be accomplished in any of a number of ways. For
example, in some embodiments, a shape-changing portion may be
sectioned, notched, slotted or segmented and one of more tensioning
cords, wires or other tensioning devices coupled with the
shape-changing portion may be used to shape and rigidify
stabilizing member 102. A segmented stabilizing member, for
example, may include multiple segments coupled with two tensioning
cords, each cord providing a different direction of articulation to
the stabilizing member. A first bend may be created by tensioning a
first cord to give the stabilizing member a C-shape or similar
shape to conform to the valve annulus, while a second bend may be
created by tensioning a second cord to articulate the C-shaped
member upwards against the annulus. In various embodiments, any
configurations and combinations may be used to give stabilizing
member 102 a desired shape.
[0050] In transthoracic and other embodiments, stabilizing member
102 may be pre-shaped, and the method may simply involve
introducing stabilizing member 102 under the valve leaflets. The
pre-shaped stabilizing member 102 may be rigid or formed from a
shape memory material such as nitinol, spring stainless steel, or
the like.
[0051] Once stabilizing member 102 is positioned under the annulus,
force may be applied to stabilize the valve annulus VA, as shown in
FIG. 1B. Such force may be directed in any suitable direction to
expose, position and/or stabilize the annulus. For example, upward
and lateral force is shown in FIG. 1B by the solid-headed arrow
drawn from the center of stabilizing member 102. In other cases,
only upward, only lateral, or any other suitable force(s) may be
applied. With application of force to stabilizing member 102, the
valve annulus VA is caused to rise or project outwardly, thus
exposing the annulus for easier viewing and access. The applied
force may also stabilize the valve annulus VA, also facilitating
surgical procedures and visualization.
[0052] With reference now to FIG. 2, one embodiment of a
stabilization device 200 may include an upper or atrial stabilizing
member 202, coupled with an outer shaft 210, and a lower or
ventricular stabilizing member 204 coupled with an inner shaft 212.
Upper stabilizing member 202 and lower stabilizing member 204 are
typically adapted for placement above and below a valve annulus,
such as the mitral valve annulus. Stabilizing members 202 and 204
will typically be formed from an elastic material having a geometry
selected to engage and optionally shape or constrict the valve
annulus. For example, the rings may be formed from shape memory
alloy, such as nitinol, from a spring stainless steel, or the like.
In other instances, however, the stabilizing members could be
formed from an inflatable or other structure can be selectively
rigidified in situ, such as a gooseneck or lockable element shaft,
any of the rigidifying structures described above, or any other
rigidifying structure.
[0053] As described above, the device 200 may be introduced to the
left atrium of a beating heart, either transeptally or through an
incision in the heart wall. Once in the atrium, the lower or
ventricular stabilizing member will be introduced through the
mitral valve opening, with a corner 206 of the stabilizing member
typically being engaged against a commisure. The ventricular
stabilizing member 204 may be adjusted so that it lies at a
junction between the valve leaflet L and the ventricular wall VW,
as illustrated in FIG. 3. The upper or atrial stabilizing member
202 may then be clamped down onto the upper surface of the annulus
VA, typically by sliding outer shaft 210 down over inner shaft 212.
Thus, the annulus will be circumferentially clamped between the
stabilizing members, again as observed in FIG. 3. Such clamping
will stabilize the annulus relative to the remainder of the beating
heart, thus facilitating subsequent minimally invasive surgical
procedures. For example, and with reference now to FIG. 4, a clip
applier may be used to introduce individual tethered clips 156 into
the valve annulus VA. Exemplary clip appliers for applying tethered
clips to a valve annulus are described more fully in U.S. patent
application Ser. No. 10/461,043, which was previously incorporated
by reference. Alternatively, atrial stabilizing member 202 could be
replaced with a circular clip applier 220, as shown in FIG. 5. A
stabilizing device employing such a clip applier could be used to
simultaneously stabilize the annulus and deliver clips 222 using a
clip driver, such as a balloon 224.
[0054] Although not illustrated, in some instances it may be
desirable to provide a third stabilizing element on the exterior of
the heart, optionally between the coronary sinus CS and circumflex
artery CF or within the coronary sinus.
[0055] As is described further below, any stabilizing member,
including an atrial stabilizing member, a ventricular stabilizing
member, or both, may include one or more devices for treating a
valve annulus. Such devices may include any suitable device for
treating an annulus, and the present invention is not limited to
any specific embodiments. For example, in some embodiments a
stabilizing member comprises a housing for containing a plurality
of tethered anchors and a system for delivering the anchors into
annular tissue. "Anchors" may comprise curved hooks, straight
hooks, barbed hooks, clips of any kind, T-tags, shape memory hooks,
or any other suitable fastener(s). Delivery of anchors may be
accomplished by any suitable device and technique, such as by
hydraulic balloon delivery as discussed below. Alternatively, any
other suitable treatment may be delivered to an annulus. For
example, energy such as radiofrequency energy may be delivered to
the annulus via a stabilizing member to constrict the annular
tissue. Alternatively, a shape memory stent may be delivered to the
annulus such that when deployed the stent longitudinally shrinks to
constrict the annulus. In other embodiments, one or more drugs or
bulking agents may be administered to the annulus. Therefore,
although the following description focuses on delivery of a
plurality of tethered hooks to a valve annulus, many other types of
anchors and other treatment modalities may alternatively be
delivered using devices and methods of the invention.
[0056] That being said, and referring now to FIGS. 5A and 5B, in
one embodiment, upper stabilizing member 202 could be replaced with
a circular hook applier 230, including a housing for multiple
tethered hooks 232 and a hook driver such as a balloon 234. Again,
hooks 232 may be replaced by any other anchors in various
embodiments. Hooks 232 may be coupled to the device via a pivot
mandrel 236, so that when balloon 234 is inflated, as in FIG. 5B,
hooks 232 pivot around mandrel 236 to enter tissue of the valve
annulus VA. Hydraulically driving curved hooks 232 in this way
closely replicates the motion of a surgeon manually driving a
suture needle into tissue and allows hooks 232 to be driven
strongly into the tissue of the valve annulus VA. After hooks 232
are engaged with the valve annulus VA, they may be cinched, using
the tether (not shown), to decrease the diameter of the annulus and
thus the valve. The housing, the balloon 234 and the pivot mandrel
236 may be withdrawn before or after cinching.
[0057] As mentioned above, in various embodiments other anchor
delivery mechanisms may be used, although one or more expandable
balloons are used in one embodiment. For example, other hydraulic
delivery systems may be used, anchors may be advanced into tissue
using a pull-cord, or the like. In some embodiments, treatment
devices and delivery mechanisms may be incorporated into
lower/ventricular stabilizing member 204, rather than upper/atrial
stabilizing member 202. In still other embodiments, some of which
are described immediately below, both stabilizing members 202 and
204 may include devices for treatment of the valve annulus VA.
[0058] Additionally, and with reference now to FIGS. 5C and 5D,
some embodiments may include one or more fasteners and fastener
receiving pieces. For example, a circular hook applier 240,
including multiple tethered hooks 242 on a pivot mandrel 246 and a
balloon 244 may be disposed on the upper, atrial side of the valve
annulus VA, and lower stabilizing member 204 may carry one or more
receiving pieces 248 for receiving part of one or more of hooks
242. As shown in FIG. 5D, when balloon 244 is inflated, it drives
hooks 242 in a curved path through tissue of the valve annulus VA
and into receiving piece 248. Receiving piece 248 may comprise any
suitable material with any configuration for receiving and holding
a portion of hooks 242. In some embodiments, for example, receiving
piece 248 may comprise a Dacron strip, while in other embodiments
the fastener and fastener receiving piece may be configured similar
to a plastic garbage bag tie or the like. Any configuration is
contemplated within the scope of the invention. In alternative
embodiments, anchors may be driven from lower stabilizing member
204 into a receiving piece carried by upper stabilizing member
202.
[0059] Referring now to FIGS. 6, 7 and 8, one embodiment of a
stabilizing and hook delivery device 260 is shown. Typically, hook
delivery device 260 will include an elongate housing or shaft 261,
which will house a series of hooks 264 coupled to housing 261 via a
pivot mandrel 266 and coupled to one another via a tether 268.
Housing 262 will also include one or more expandable balloons 262
for driving hooks 264. Housing 262 may be flexible or rigid in
various embodiments. Of course, any number, size and shape of hooks
264 (or other anchors) may be included in housing 261. Tether 268
may be one long piece of material or two or more pieces and may
comprise any suitable material, such as suture, suture-like
material, a Dacron strip or the like. Pivot mandrel 268 may also
have any suitable configuration and be made of any suitable
material. In one embodiment, mandrel 268 is made of a metal such as
stainless steel, titanium or nitinol. Expandable balloon 262 may
have any suitable size and configuration. In some embodiments, more
than one balloon may be used. As shown in FIG. 8, inflating balloon
262 drives hooks 264 in a curvilinear path (arrows) into adjacent
tissue (not shown). Hooks thus driven into tissue of a cardiac
valve annulus may then be cinched, via tether 268, to reduce the
valve diameter, thus treating or ameliorating valve
regurgitation.
[0060] Although the foregoing is a complete and accurate
description of the present invention, the description provided
above is for exemplary purposes only, and variations may be made to
the embodiments described without departing from the scope of the
invention. Thus, the above description should not be construed to
limit the scope of the invention as described in the appended
claims.
* * * * *