U.S. patent application number 10/776682 was filed with the patent office on 2005-05-19 for devices and methods for heart valve repair.
This patent application is currently assigned to GUIDED DELIVERY SYSTEMS, INC.. Invention is credited to Morales, Rodolfo A., Starksen, Niel F..
Application Number | 20050107810 10/776682 |
Document ID | / |
Family ID | 29741063 |
Filed Date | 2005-05-19 |
United States Patent
Application |
20050107810 |
Kind Code |
A1 |
Morales, Rodolfo A. ; et
al. |
May 19, 2005 |
Devices and methods for heart valve repair
Abstract
Methods and devices provide constriction of a heart valve
annulus to treat cardiac valve regurgitation and other conditions.
Embodiments typically include a device for attaching a cinching or
tightening apparatus to a heart valve annulus to reduce the
circumference of the annulus, thus reducing valve regurgitation.
Tightening devices may include multiple tethered clips, multiple
untethered crimping clips, stabilizing devices, visualization
devices, and the like. In one embodiment, a plurality of tethered
clips is secured circumferentially to a valve annulus, and the
tether coupling the clips is cinched to reduce the circumference of
at least a portion of the annulus. Methods and devices may be used
in open heart surgical procedures, minimally invasive procedures,
catheter-based procedures, and/or procedures on beating hearts or
stopped hearts.
Inventors: |
Morales, Rodolfo A.; (Los
Gatos, CA) ; Starksen, Niel F.; (Los Altos Hills,
CA) |
Correspondence
Address: |
HAYNES BEFFEL & WOLFELD LLP
P O BOX 366
HALF MOON BAY
CA
94019
US
|
Assignee: |
GUIDED DELIVERY SYSTEMS,
INC.
Los Altos Hills
CA
|
Family ID: |
29741063 |
Appl. No.: |
10/776682 |
Filed: |
February 10, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10776682 |
Feb 10, 2004 |
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10461043 |
Jun 13, 2003 |
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60462502 |
Apr 10, 2003 |
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60445890 |
Feb 6, 2003 |
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60429288 |
Nov 25, 2002 |
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60388935 |
Jun 13, 2002 |
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Current U.S.
Class: |
606/143 |
Current CPC
Class: |
A61B 17/00234 20130101;
A61B 17/0684 20130101; A61B 17/3423 20130101; A61B 1/00096
20130101; A61B 8/12 20130101; A61B 2017/0496 20130101; A61B 1/00082
20130101; A61B 17/0401 20130101; A61F 2/2451 20130101; A61B 17/10
20130101; A61B 17/3421 20130101; A61B 2017/06023 20130101; A61F
2/2445 20130101; A61B 2017/3484 20130101; A61B 2017/00243 20130101;
A61B 17/0644 20130101; A61B 1/04 20130101; A61B 17/083 20130101;
A61B 17/0487 20130101; A61B 2017/0488 20130101; A61B 2017/3488
20130101; A61B 2017/3425 20130101; A61B 17/1285 20130101 |
Class at
Publication: |
606/143 |
International
Class: |
A61B 017/10 |
Claims
1. A device for applying tethered clips to an annulus, the device
comprising: a shaft having a proximal end and a distal end; a
plurality of clips slidably coupled to a tether, the tethered clips
delivered by the shaft; a clip applier at or near the distal end of
the shaft for securing the clips to the annulus; and at least one
actuator at or near the proximal end of the shaft for causing the
device to advance the clips and for activating the clip applier to
secure the clips to the annulus.
2. A device as in claim 1, wherein the clip applier comprises: a
pusher coupled with the actuator for advancing the clips; and at
least one slot in an inner surface of the shaft for guiding the
clips.
3. A device as in claim 2, wherein the clip applier further
comprises a clip crimping member.
4. A device as in claim 3, wherein the at least one actuator
includes means for cinching the tethered clips to reduce the
circumference of the valve annulus.
5. A device as in claim 1, wherein the at least one actuator is
selected from the group consisting of a trigger, a handle, a
plunger, a squeeze-activated device, a syringe-grip device and a
foot-operated device.
6. A device as in claim 1, wherein each of the plurality of clips
includes at least one eyelet, and the tether passes through the at
least one eyelet of each clip.
7. A device as in claim 6, wherein each of the plurality of clips
includes two eyelets, and the tether has parallel segments passing
through both eyelets of each clip.
8. A device as in claim 6, farther comprising means for crimping
the at least one eyelet of any of the plurality of clips such that
a clip with a crimped eyelet is secured to the tether.
9. A device as in claim 1, wherein the distal end of the shaft
comprises a curved tip.
10. A device as in claim 1, wherein the shaft is introducible into
a patient through a minimally invasive incision.
11. A device as in claim 1, further comprising a tether anchor
coupled to the tether and carried by the shaft.
12. A device as in claim 11, wherein the tether anchor comprises a
rivet.
13. A device as in claim 11, wherein the tether anchor is coupled
with at least a last clip of the tethered clips such that crimping
the last clip secures the last clip to the tether anchor and the
tether anchor to the tether.
14. A device as in claim 13, wherein the tether anchor is further
coupled with a penultimate clip, such that crimping the penultimate
clip secures the penultimate clip to the tether anchor and the
tether anchor to the tether.
15. A device as in claim 1, wherein the tether is selected from the
group consisting of a suture material, a Teflon strip, a band, a
filament, a wire and a strap.
16. A device for applying tethered clips to an annulus, the device
comprising: a shaft having a proximal end and a distal end, a
tether having at least two parallel segments; a plurality of clips
which slidably receive both segments of the tether, wherein said
clips are arranged successively on said tether, and a clip applier
at or near the distal end of the shaft for securing clips to the
annulus while said clips remain on said tether.
17. A device as in claim 16, wherein the clips each include a pair
of spaced-apart eyelets, wherein one segment is received in each
eyelet of the pair.
18. A device as in claim 17, wherein the clips are deformable in
the region of the eyelets to permit crimping.
19. An annular fastener comprising: a tether comprising first and
second segments, and a plurality of clips, each clip comprising
first and second tether-receiving elements, wherein one segment is
received in each of the tether-receiving elements on each clip.
20. An annular fastener as in claim 19, further comprising a
terminal clip which is fixed to a leading end of the tether.
21. An annular fastener as in claim 19, wherein the plurality of
clips includes at least three clips.
22. An annular fastener as in claim 19, wherein the clips are
deformable in the region of the tether-receiving elements to permit
crimping.
23. A system comprising: a device as in claim 1; and a
stabilization device adapted to capture and immobilize the annulus
relative to the remainder of the heart.
24. A system as in claim 23, wherein the stabilization device
comprises a pair of rings which are adapted to clamp opposed faces
of the annular surface.
25. A system as in claim 24, wherein the device is adapted to clamp
over and under a heart valve annulus.
26. A system comprising: a device as in claim 16, and a
stabilization device adapted to capture and immobilize the annulus
relative to the remainder of the heart.
27. A system as in claim 26, wherein the stabilization device
comprises a pair of rings which are adapted to clamp opposed faces
of the annulus.
28. A system as in claim 26, wherein the device is adapted to clamp
over and under a heart valve annulus.
29. A system comprising: a device as in claim 1; and a
visualization device adapted to directly view a valve annulus in a
heart chamber.
30. A system as in claim 29, wherein the visualization device
comprises an ultrasonic imaging transducer.
31. A system as in claim 29, wherein the visualization device
comprises an optical viewing element disposed in a transparent
element.
32. A system as in claim 31, wherein the transparent element
comprises a transparent balloon inflatable with a transparent
inflation medium.
33. A system comprising: a device as in claim 16; and a
visualization device adapted to directly view a valve annulus in a
heart chamber.
34. A system as in claim 33, wherein the visualization device
comprises an ultrasonic imaging transducer.
35. A system as in claim 33, wherein the visualization device
comprises an optical viewing element disposed in a transparent
element.
36. A system as in claim 34, wherein the transparent viewing
element comprises a transparent balloon inflatable with a
transparent inflation medium.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application is a division of and claims the benefit of
priority from U.S. patent application Ser. No. 10/461,043 (Attorney
Docket No. 016886-000310US), filed Jun. 13, 2003, which claimed the
benefit under 35 USC 119(e) of U.S. Provisional Application Nos.
60/388,935 (Attorney Docket No. 016886-000300US), filed on Jun. 13,
2002; 60/429,288 (Attorney Docket No. 016886-000700US), filed on
Nov. 25, 2002; 60/445,890 (Attorney Docket No. 016886-000800US),
filed on Feb. 6, 2003, and 60/462,502 (Attorney Docket No.
016886-001100US), filed on Apr. 10, 2003, the full disclosures of
which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to medical methods
and devices. More particularly, the invention relates to methods
and devices for circulatory valve repair, especially for the repair
of heart valves, such as repair of the mitral or tricuspid valve
for treating mitral or tricuspid regurgitation.
[0004] Four valves in the heart direct blood flow through the heart
in a forward direction. On the left side of the heart, the mitral
and aortic valves direct oxygenated blood from the lungs to the
aorta for distribution to the body. On the right side of the heart,
the tricuspid and pulmonary valves direct de-oxygenated blood from
the body to the pulmonary arteries for distribution to the
lungs.
[0005] The four heart valves consist of moveable leaflets that open
and close in response to differential pressures on either side of
the valve. The mitral valve, for example, has two leaflets while
the tricuspid valve has three. The components of the mitral valve
assembly include a mitral valve annulus, an anterior leaflet, a
posterior leaflet, two papillary muscles which are attached at
their bases to the interior surface of the left ventricular wall,
and multiple chordae tendineae, which are cord-like structures that
couple the mitral valve leaflets to the papillary muscles. The
other heart valves have similar supporting structures, though each
is somewhat unique.
[0006] If a functional problem occurs in one or more heart valves,
cardiac function is often adversely affected. Such valve problems
may be classified as either stenosis, in which a valve does not
open properly, or insufficiency (also known as regurgitation), in
which a valve does not close properly. Mitral regurgitation, for
example, is typically caused by dysfunction of the mitral annulus,
subvalvular apparatus, or direct injury to the valve leaflets.
Severe mitral regurgitation is a serious problem which, if left
untreated, can adversely affect cardiac function and compromise a
patient's quality of life and longevity. In cases where an
atrioventricular valve becomes regurgitant due to damage to the
valve supporting structures, papillary muscles, leaflets or annular
geometry, the fraction of blood in the ventricle that is actually
moved forward with each beat is reduced. To compensate, the
ventricular cavity enlarges in an attempt to maintain forward
output. By enlarging, the heart attempts to maintain the same
absolute volume of forward flow by ejecting a reduced percentage of
a larger volume. This enlargement of the ventricle is accompanied
by an enlargement of the supporting structures and annulus of the
valve, resulting in separation of the valve leaflets at their point
of co-aptation during ventricular systole and further leaking of
blood retrograde across the valve. This continues the cycle of
ventricular enlargement, annular dilatation and regurgitation and
subsequent loss of forward output and progressive heart failure.
Other heart valve problems often cause similarly grave
sequelae.
[0007] Treatment of heart valve stenosis or regurgitation, such as
mitral or tricuspid regurgitation, often involves an open-heart
surgical procedure to replace or repair the valve. Repair of a
regurgitant valve such as the mitral valve is often performed in
preference to replacement. Such procedures generally require a
large incision into the thorax of the patient (a thoracotomy),
sometimes requiring a median sternotomy (cutting through the middle
of the sternum). Such procedures routinely include a corrective
procedure called an annuloplasty, designed to restore the valve
annulus shape, strengthen the annulus, and allow better leaflet
co-aptation as a part of the repair. Such open heart procedures
also usually 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 that a relatively large
incision be made through the wall of the heart to access the valve.
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 committed to progressive
deterioration and cardiac enlargement. Often, such patients have no
feasible alternative treatments for their heart valve
conditions.
[0008] Therefore, it would be advantageous to have methods and
devices for repairing a mitral valve to treat mitral regurgitation
in a less invasive manner than is available through current
techniques. In some instances, it may be advantageous to provide
for repair of a mitral valve, as well as other heart valves,
through minimally invasive incisions or intravascularly. In other
cases, it may be beneficial to use improved devices and methods in
an open heart surgical procedure, on either a beating heart or a
stopped heart. In beating heart procedures, including both
minimally invasive and intravascular access procedures, it would be
useful to provide for stabilization of the valve annulus while any
procedure is being performed. In such beating heart procedures, it
would be further useful to provide systems for the direct
observation of the valve annulus from within a heart chamber to
facilitate performing desired interventions. Moreover, it would be
still further desirable if the apparatus and systems of the present
invention were useful for treating not only the annulus of heart
valves, but also other natural and created holes in tissue which
require strengthening or closing. Improved devices and methods
would ideally be relatively simple and easy to use and would enable
durable, long-lasting mitral valve repair, either in a minimally
invasive or open heart procedure, for many patients who are not
candidates for more conventional procedures. At least some of these
objectives will be met by the present invention.
[0009] 2. Description of the Background Art
[0010] Published U.S. Application 2002/0163784A12 describes a port
for providing access to a beating heart to perform diagnostic and
therapeutic procedures, including a stapled annuloplasty procedure.
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
[0011] Methods and devices provide heart valve repair for mitral
valve regurgitation and other heart valve conditions. Embodiments
typically include a device for attaching a cinching or tightening
apparatus to a heart valve annulus to reduce the circumference of
the annulus, thus reducing valve regurgitation. Tightening devices
include multiple tethered clips, multiple tethered or untethered
crimping (deformable) clips, apparatus for delivering such clips,
apparatus for selectively deforming clips onto the tether, systems
for stabilizing the valve annulus during interventions, systems for
viewing the valve annulus during an intervention, and the like.
[0012] As used hereinafter, the term "clips" is intended to refer
to a wide variety of tissue anchors or fasteners which are able to
(1) penetrate and fix to tissue, particularly into the fibrous
tissue of a heart valve annulus and (2) provide for a secure
attachment to a tether. Usually, the clips will initially be
slidably received over the tether, e.g., through eyelets as
described in greater detail hereinafter. Particular ones of the
clips, however, may be fixedly secured to the tether even at the
outset of the procedure. For example, often at least a first clip
will be fixed to a lead end of the tether, where the first clip
will be initially deployed into the annulus and will serve as an
anchor at one end of the tether which is deployed about the
annulus. Usually the remaining clips, including a series of
intermediate clips and at least one terminal clip, will remain
slidably secured over the tether until one of more of those clips
is crimped or otherwise fixed to the tether during the
interventions, as described in more detail below.
[0013] While the methods of the present invention are directed
particularly at constricting a valve annulus, particularly for the
treatment of valve regurgitation, the apparatus of the present
invention may find broader applications. In particular, the clip
deploying apparatus of the present invention may be used whenever
it is desired to deliver a plurality of sequential clips, either in
a straight line or in a curved line, in order to tighten tissue or
optional to tether portions of tissue which are separate or which
have been traumatically severed. Thus, the apparatus claimed herein
are not meant to be limited in any way by the exemplary methods in
which they are being used.
[0014] Generally, in accordance with the principles of the present
invention, a plurality of tethered clips is secured
circumferentially to a valve annulus, and the tether coupling the
clips is cinched to reduce the circumference of at least a portion
of the annulus. Optionally, at least a terminal clip may be
deformed, such as by crimping, to secure the clip(s) to the tether,
and the tether may pass through one, two or more eyelets on each
clip. Methods and devices may be used in open heart surgical
procedures, minimally invasive procedures and/or procedures on
beating hearts or stopped hearts. Furthermore, a heart valve may be
accessed by any suitable route, such as any veinous access route,
through any incision(s) in the heart wall and/or atrial septum,
through any heart chamber and/or through the aorta.
[0015] In one aspect of the invention, a method for constricting a
valve annulus comprises introducing a plurality of clips to a heart
valve annulus, the clips being coupled with a tether, securing
individual clips at circumferentially spaced-apart locations about
at least a portion of the annulus, and cinching the tether to
circumferentially tighten the annulus. At least a first clip at a
lead end of the tether is usually fixed to the tether, and the
remaining clips are usually slidably coupled to the tether to
facilitate cinching. Often, all of a series of intermediate clips
and at least a single terminal clip will be introduced to the
annulus prior to cinching by applying tension to the free end of
the tether. After the proper amount of tension is applied, the
terminal clip(s) will then be crimped onto or otherwise fixed to
the tether to maintain the desired degree of annular constriction.
Of course, it may be desirable to crimp or otherwise fix two or
more clips at the lead end of the tether and/or two or more clips
at the terminal end of the tether to help assure that the tether
will not loosen. In some instances, it may even be desirable to
deform or otherwise fix each and every clip to the tether after the
desired level of cinching has been achieved. In general, however,
the methods of the present invention will not rely on cinching a
clip immediately after that clip is placed in order to placate
tissue between adjacent clips. Deforming the portion of the at
least one clip may involve applying force to at least one eyelet on
the clip to reduce the inner diameter of the eyelet and secure the
tether within the eyelet. Some embodiments may involve deforming
two eyelets on a clip to secure the tether within each of the two
eyelets.
[0016] In some embodiments, introducing the plurality of clips
comprises advancing a tethered clip applicator through an incision
in a wall of the heart to a desired location for treating the heart
valve annulus. For example, the applicator will be introduced
through an incision in the left atrial wall of the heart in some
embodiments, to a location at or near the posterior or anterior
commisure of the mitral valve annulus. Some embodiments further
include placing an instrument introduction device through the
incision in the wall of the heart, and the clip applicator is
advanced through the instrument introduction device. Optionally,
such embodiments may also include securing the introduction device
to the heart wall before the advancing step. In some embodiments,
the instrument introduction device comprises a valve, a diaphragm
and/or a hemostatic barrier for allowing passage of the clip
applicator and any other devices while preventing outflow of blood
from the heart. In one embodiment, for example the clip applicator
is generally an elongate hand-held applicator, insertable through
the introduction device.
[0017] In some embodiments, securing the individual clips comprises
securing a first tethered clip to the heart valve annulus and
securing a plurality of subsequent tethered clips at
circumferentially spaced-apart locations about at least a portion
of the annulus. In some cases, the first clip is pre-secured the
tether. In other cases, securing the first tethered clip to the
valve annulus includes deforming a portion of the first tethered
clip to secure it to the tether. Alternatively, a portion of the
first tethered clip may be deformed after securing the clip to the
annulus to secure the first clip to the tether. In still other
embodiments, a portion of the first tethered clip may be deformed
before securing the clip to the annulus to secure the first clip to
the tether. In some embodiments, the plurality of subsequent
tethered clips are slidably coupled with the tether. Optionally,
such embodiments may further include deforming a portion of at
least a second clip to secure the second clip to the tether.
[0018] In some embodiments, cinching generally involves applying
tensile force to the tether. A method may further include deforming
a portion of at least one of the plurality of subsequent tethered
clips after the cinching step to secure the at least one
partially-deformed clip to the tether. For example, deforming a
portion of the at least one clip may involve deforming a last clip
of the subsequent tethered clips. Optionally, such embodiments may
further include deforming at least a penultimate clip of the
subsequent tethered clips.
[0019] Some embodiments also include securing a tether anchor,
coupled to the tether, to the valve annulus adjacent a last clip of
the individual clips. For example, securing the tether anchor may
involve securing a rivet to the valve annulus. Such embodiments may
also include deforming a portion of the last clip around the rivet
to secure the tether to the rivet and secure the last clip to the
annulus. Optionally, a portion of a penultimate clip may also be
deformed around the rivet to secure the tether to the rivet and
secure the penultimate clip to the annulus.
[0020] Some embodiments of the method further involve visualizing
the heart valve using at least one visualization device. For
example any one of (or combination of) an ultrasound device, an
angioscopic device, a transesophageal echocardiogram device and a
fluoroscopic device may be used for visualization. In some
embodiments, an ultrasound device comprising a gel-containing cone
for enhancing ultrasound visualization may be used. Some
embodiments may involve using a real-time Doppler ultrasound device
to visualize a regurgitant flow across the heart valve during at
least the cinching step. Optionally, such methods may also include
visualizing a reduction in the regurgitant flow during the cinching
step and selecting an amount of cinching based on the reduction in
the regurgitant flow in real time. Particularly useful
visualization may be accomplished using optical viewing elements
disposed directly in the heart chamber, typically adjacent to the
valve annulus or other target tissue being treated. Particularly in
beating heart procedures, such optical visualization will be
accomplished using a transparent element to exclude blood, such as
a lens, a solid optically transparent block, or most preferably a
transparent inflatable balloon which may be inflated with a
transparent inflation medium. By engaging such balloon against the
surface to be visualized, direct and highly accurate visualization
of the annulus may be accomplished. In some embodiments, the
optical or other visualization device is coupled with a device for
introducing and securing the clips, such as the clip
applicator.
[0021] As mentioned above, the introducing, securing and cinching
steps may be performed as part of any suitable procedure, from any
suitable access route, and the like. For example, the may be
performed as part of an open heart surgical procedure, with or
without stopping the heart, through one or more minimally invasive
incisions and/or intravascularly. Furthermore, any suitable
cardiovascular valve may be treated, such as the mitral valve,
tricuspid valve or the like.
[0022] In another aspect, a method for inhibiting heart valve
regurgitation comprises: introducing a plurality of crimping clips
to a heart valve annulus; securing individual crimping clips at
circumferentially spaced-apart locations about at least a portion
of the annulus; and crimping at least one of the clips to
circumferentially tighten the annulus. Crimping clips may generally
be tethered or untethered, but in one embodiment the crimping clips
are slidably coupled with a tether, and the method further includes
cinching the tether to circumferentially tighten the annulus.
Cinching typically involves applying tensile force to the tether.
In some embodiments, crimping a tethered clip secures the crimped
clip to the annulus and to the tether. In some embodiments, for
example, crimping a clip comprises compressing at least one eyelet
in the clip, the tether running through the eyelet. In some
embodiments, the clips each have two eyelets and the tether runs
through the two eyelets on each clip.
[0023] In some embodiments, crimping comprises crimping a first
clip before the cinching step to secure the first clip to the
annulus and the tether and crimping at least a last clip after the
cinching step to secure the last clip to the annulus and the
tether. Various embodiments may further include crimping at least a
penultimate clip to secure the penultimate clip to the annulus and
the tether. Crimping may further involve crimping at least the last
clip around a tether anchor to secure the last clip to the tether
anchor and secure the tether anchor to the annulus.
[0024] In many embodiments, at least the introducing and securing
steps are performed using an elongate, hand-held, surgical device.
The surgical device may include an actuator at or near its proximal
end for performing at least the securing step. In some embodiments,
for example, the actuator may include, but is not limited to a
trigger, a handle, a plunger, a squeeze-activated device and a
syringe-grip device.
[0025] In yet another aspect, a method for inhibiting heart valve
regurgitation comprises securing a flexible cord about at least a
portion of the annulus of the valve and cinching the flexible cord
to reduce the annular circumference. As with the above procedures,
such a method may be performed as part of an open heart surgical
procedure, with or without stopping the heart, through one or more
minimally invasive incisions, intravascularly, or via any other
suitable approach.
[0026] In some embodiments, securing and cinching are performed
through a small incision in a wall of the heart. Such embodiments
may further include placing an instrument introduction device in
the heart wall through the incision before performing the securing
and cinching steps. This method may further include securing the
instrument introduction device to the wall. The instrument
introduction device may include, for example, a valve for allowing
passage of one or more surgical instruments while preventing
outflow of blood from the heart through the valve. The method may
optionally further include introducing at least one surgical
instrument into a chamber of the heart through the instrument
introduction device. For example, at least one elongate, hand-held
instrument may be introduced for performing the securing and
cinching steps.
[0027] As described above, in any of the above methods, one or more
visualization devices may be used, such as ultrasound and/or
transesophageal echocardiogram devices. Also as mentioned above,
the methods may be used to operate on any suitable cardiovascular
valves, such as a mitral, tricuspid, aortic or pulmonary valve.
[0028] In still further embodiments of the methods of the present
invention, a heart valve annulus of a beating heart is constricted
by first stabilizing the heart valve annulus. After the annulus is
stabilized, individual clips are secured at circumferentially
spaced-apart locations about at least a portion of the annulus. A
tether passed through the clips may be cinched in order to
circumferentially tighten the annulus. Stabilization of the beating
heart is very beneficial in both minimally invasive and
intravascular (closed-chest) procedures.
[0029] The valve annulus may be stabilized in a variety of ways.
Usually, stabilization will involve engaging the annulus with at
least a first stabilizing ring which is typically in the case of a
mitral valve disposed beneath the valve leaflets to engage an
intersection between the leaflets and the interior ventricular
wall. Usually, the stabilization ring will be introduced from the
left atrium, together with the other interventional tool(s), to a
location at the valve commisure. A curved or C-shaped component of
the stabilizer will then be deployed beneath the valve annulus.
Preferably, a second stabilization ring will be introduced to a
location above the valve annulus, where the first and second
stabilizing rings will typically have similar or congruent
geometries permitting clamping of the valve annulus therebetween.
Optionally, either or both of the stabilizing rings may be further
provided with a vacuum source, microhooks, adhesives, or the like
to assist in engaging and capturing the tissue of and surrounding
the valve annulus. Still further optionally, the stabilization ring
disposed above the valve annulus may be adapted to deliver clips
directly to the tissue, thus in some cases eliminating the need for
a separate clip applier as described elsewhere in this application.
Alternatively, of course, the clips may be successively applied
from an applicator, as described elsewhere herein, which is
advanced around at least a portion of the valve annulus while the
valve annulus remains stabilized. When using a separate clip
applicator, the stabilizing ring or other stabilization apparatus
may provide a template to guide the applicator around the annulus
as clips are applied. In most cases, the stabilization device will
also shape the annulus to a geometry compatible with the
applicator. After the clips are delivered, the rings or other
stabilizing device will be removed, and the tether cinched to
constrict the annulus as described elsewhere herein.
[0030] In yet another aspect of the method of the present
invention, valve annulus may be constricted in a beating heart
while directly viewing at least a portion of the valve annulus from
within the atrium (left atrium in the case of the mitral valve).
Individual clips are secured at circumferentially spaced-apart
locations about at least a portion of the valve annulus while
annulus remains under direct viewing. After the clips are properly
placed, as confirmed by direct viewing, the tether may be cinched
through the clips to circumferentially tighten the annulus, as
generally described elsewhere in the application. Such direct
viewing may be accomplished using an ultrasonic imaging element,
for example one placed on a clip applier. More preferably, however,
direct viewing may be accomplished by engaging a transparent
element against the valve annulus and optically viewing the annulus
through said element. Usually, the transparent element comprises an
inflatable balloon which is inflated with a transparent inflation
medium. Optical viewing may then be performed from within the
inflated balloon using a fiberoptic scope, a CCD (charged coupled
device), other type of camera, or the like.
[0031] In yet another aspect, a device for applying tethered clips
to a heart valve annulus comprises a shaft having a proximal end
and a distal end and a plurality of clips slidably coupled to a
tether. The tethered clips are carried by the shaft; and the device
further includes a clip applier at or near the distal end of the
shaft for securing the clips to the annulus and at least one
actuator at or near the proximal end of the shaft for causing the
device to advance the clips and for activating the clip applier to
secure the clips to the annulus. Optionally, the means for
selectively advancing and securing the clips may further comprise a
pusher coupled with the actuator for advancing the clips and at
least one slot in an inner surface of the shaft for guiding the
clips.
[0032] In some embodiments, the clip applier comprises a clip
crimping member. Also in some embodiments, the at least one
actuator includes means for tensioning and cinching the tethered
clips to reduce the circumference of the valve annulus. The
actuator itself may comprise any suitable device(s), such as but
not limited to a trigger, a handle, a plunger, a squeeze-activated
device, a syringe-grip device and/or any suitable foot-operated
device.
[0033] In some embodiments, each of the plurality of clips includes
at least one eyelet, and the tether passes through the eyelet of
each clip. Optionally, in some embodiments, each clip includes two
eyelets, and the tether passes through both eyelets of each clip.
In such embodiments, the device may further include means for
crimping the at least one eyelet of any of the plurality of clips
such that a clip with a crimped eyelet is secured to the
tether.
[0034] In some embodiments, the shaft comprises an elongate,
hand-held shaft. Optionally, the shaft may be introducible into a
patient through a minimally invasive incision. In these or other
embodiments, a tether anchor may be coupled to the tether and
carried by the shaft. For example, the tether anchor may comprise a
rivet. The tether anchor may be coupled with at least a last clip
of the tethered clips such that crimping the last clip secures the
last clip to the tether anchor and the tether anchor to the tether.
In some embodiments, the tether anchor is further coupled with a
penultimate clip, such that crimping the penultimate clip secures
the penultimate clip to the tether anchor and the tether anchor to
the tether.
[0035] The tether itself may comprise any material or
configuration. In some embodiments, for example, the tether
comprises at least one of a suture material, a Teflon strip, a
band, a filament, a wire and a strap. Embodiments including tethers
may optionally also include means for cinching the tethered clips
to reduce the circumference of the valve annulus.
[0036] In another aspect, a device for applying tethered clips to a
heart valve annulus comprises: a shaft having a proximal end and a
distal end, a plurality of clips slidably coupled to a tether, the
tethered clips carried by the shaft; a clip applier at the distal
end of the shaft for securing the clips to the valve annulus; and
tensioning means for providing tension to the tether to cinch the
tether, thus reducing a diameter of the valve annulus. In some
embodiments, the clip applier comprises means for partially
deforming at least one of the clips to secure the deformed clip(s)
to the tether. In some embodiments, the tensioning means allows for
tensioning of the tether while the clips are being secured to the
valve annulus. Optionally, the device may further include cutting
means at the distal end of the shaft for cutting an end of the
tether after the clips have been secured and cinched.
[0037] In still another aspect or the invention, a device for
treating heart valve regurgitation includes: a shaft having a
proximal end and a distal end; a rotatory cord applicator at a
location near the distal end, for securing a cord to the annulus of
the valve; and means for cinching the cord to reduce the
circumference of the valve. The shaft, for example, may comprise an
elongate, handheld shaft. In some embodiments, the means for
selectively advancing and securing the clips comprises a cable
member coupled with the shaft. The cord may comprise any of a
number of suitable materials or combinations of materials,
including but not limited to a length of suture material, a length
of Teflon strip, a wire, a band, and/or the like.
[0038] In another aspect, a device for applying crimping clips to a
heart valve annulus comprises: an elongate, handheld shaft having a
proximal end and a distal end; a plurality of crimping clips
carried by the shaft; and means for selectively advancing
individual clips, securing the individual clips to the annulus, and
crimping each individual clip to tighten at least a portion of the
valve annulus. In some embodiments, the means for selectively
advancing and securing the clips comprises a cable member coupled
with the shaft. As mentioned above, these crimping clips may be
either tethered or untethered. Thus, some embodiments further
include a tether for connecting the plurality of clips for
circumferentially tightening at least a portion of the valve
annulus.
[0039] In embodiments including a tether, the at least one actuator
may include means for cinching the tethered clips to reduce the
circumference of the valve annulus. In some embodiments, each of
the plurality of crimping clips includes at least one eyelet, and
the tether passes through the at least one eyelet of each clip. In
some embodiments, each clip includes two eyelets, and the tether
passes through both eyelets of each clip. In some embodiments,
crimping the at least one eyelet of any of the plurality of clips
such that a clip with a crimped eyelet is secured to the tether.
More generally, any of the various features described above may be
suitably used with tethered or untethered crimping clips in various
embodiments.
[0040] The present invention still further provides devices for
applying tethered clips to an annulus, where the device includes a
shaft, a tether, a plurality of clips, and a clip applier at or
near a distal end of the shaft. In particular, the tether will have
at least two parallel segments, where the segments may be separate
or may be simply two ends of a tether which has been folded over
itself. The clips slidably receive both segments of the tether,
where the clips are arranged successively on the tether. The clip
applier is adapted to secure the clips individually and usually
successively to the annulus while the clips remain on the tether.
The use of the tether having at least one additional segment is
beneficial since it provides a redundancy, i.e., if either of the
segments is severed or compromised, the other remains. Moreover, in
the specific embodiments, each of the clips includes at least one
eyelet for receiving the tethers, preferably including two eyelets
so that each segment is received in a separate eyelet. The portion
of the clips surrounding the eyelets will preferably be deformable
to provide for crimping of both eyelets around both tether
segments, again providing for redundancy.
[0041] Apparatus according to the present invention still further
includes an annular fastener. The annular fastener comprises a
tether and a plurality of clips on the tether. The tether includes
at least a pair of parallel segments, generally as described above,
and the clips include a pair of spaced-apart eyelets, where one
tether segment is received in each of the eyelets on each clip.
Usually, a terminal clip will be provided on the fastener, where
the terminal clip is fixed to a leading end of the tether, and may
or may not include two eyelets. Usually, there will be at least two
clips on the tether, more usually at least ten clips, often at
least 15 clips, and sometimes as many as 30 or more. Additionally,
at least a portion of the clips will be deformable in the region to
permit crimping.
[0042] The present invention also provides systems comprising any
of the clip delivery devices described herein. In a first instance,
the system comprises a clip applier device in combination with a
stabilization device which is adapted to capture and immobilize the
target valve or other annulus. Typically, the stabilization device
comprises a pair of rings which are adapted to clamp opposed faces
of the annulus. More typically, the clamps will be adapted to clamp
over and under a heart valve annulus.
[0043] Alternatively, systems according to the present invention
may comprise any of the clip delivery devices in combination with a
visualization device adapted to directly view a valve annulus in a
heart chamber. The visualization device may comprise an ultrasonic
imaging transducer, but will more typically comprise an optical
viewing element disposed in a transparent element. Usually, the
optical viewing element is a fiberoptic scope or a CCD, and the
transparent viewing element comprises a transparent balloon
inflatable with a transparent inflation medium.
BRIEF DESCRIPTION OF THE DRAWINGS
[0044] FIG. 1 is a side view of the left side of an upper body of a
patient, showing an incision and a device for mitral valve repair
in accordance with an embodiment of the invention.
[0045] FIG. 2A is a cut-away view of a heart, viewed from the base
of the heart, with the atria cut away to view the valves, and a
device for mitral valve repair in accordance with an embodiment of
the invention.
[0046] FIG. 2B is a perspective view of a distal end of a device
for mitral valve repair in accordance with an embodiment of the
present invention.
[0047] FIG. 2C is a perspective view of multiple tethered clips
according to an embodiment of the present invention.
[0048] FIG. 3A is a top view of a mitral valve, with several clips
placed in the mitral valve annulus, and a device for mitral valve
repair in accordance with an embodiment of the invention.
[0049] FIG. 3B is a top view of the mitral valve of FIG. 3A, with
clips in place along the length of the mitral valve annulus.
[0050] FIG. 3C is a top view of the mitral valve of FIGS. 3A-B,
with clips in place along the length of the mitral valve annulus
and with suture connecting and tightening the clips to reduce the
circumference of the annulus.
[0051] FIG. 3D is a schematic illustration of a heart valve
stabilization device which may be used in the methods of the
present invention.
[0052] FIG. 3E is a schematic illustration showing where the atrial
clamp and ventricular clamp of the stabilization of FIG. 3D will be
located on a mitral valve annulus.
[0053] FIG. 3F illustrates an exemplary clip of the present
invention which has been secured in a mitral valve annulus using
the stabilization device of FIGS. 3D and 3E.
[0054] FIG. 3G illustrates an alternative construction for a
stabilization device, where the atrial ring comprises a mechanism
for delivering clips to the valve annulus while the valve remains
stabilized with the stabilization device.
[0055] FIG. 4A is a perspective view of an instrument introduction
device for introducing a device through a heart wall in accordance
with an embodiment of the invention.
[0056] FIG. 4B is a perspective view of an instrument introduction
device as in FIG. 4A in position in a section of a heart wall, with
an instrument in place in accordance with an embodiment of the
invention.
[0057] FIG. 5A is a perspective view of a heart with a small
incision in the wall of the left atrium.
[0058] FIG. 5B is a perspective view of a heart as in FIG. 5A, with
an instrument introduction device through the wall and an
instrument placed through the device in accordance with one
embodiment of the invention.
[0059] FIG. 6 is a perspective view of a device for treating a
heart valve in accordance with an embodiment of the present
invention.
[0060] FIG. 7A is a side view of a distal end of a heart valve
treatment device having an attached ultrasound transducer as in an
embodiment of the present invention.
[0061] FIG. 7B is a side view of an ultrasound transducer and a
gel-filled cone for enhancing ultrasound visualization in
accordance with one embodiment of the present invention.
[0062] FIG. 7C illustrates an optical viewing device useful in the
methods of the present invention and comprising a fiberoptic
scope.
[0063] FIG. 7D is an enlarged view of the distal end of the device
of FIG. 7C, shown with the optical viewing scope in position within
an optically transparent balloon.
[0064] FIG. 8 is a perspective view of clips and a tether in
accordance with one embodiment of the present invention.
[0065] FIG. 9 is a side view of a surgical device for repairing a
cardiovascular valve according to one embodiment of the present
invention.
[0066] FIGS. 10A and 10B are perspective views of a crimping clip
and a tether in accordance with one embodiment of the present
invention.
[0067] FIG. 11 is a perspective view of a distal end of a surgical
device according to one embodiment of the present invention.
[0068] FIG. 11A is a close-up view of the distal end assembly of
the device shown in FIG. 11.
[0069] FIG. 12 is a perspective view of a distal end assembly of a
surgical device in the process of closing a clip, according to one
embodiment of the present invention.
[0070] FIG. 12A is a perspective view of a distal end assembly as
in FIG. 12, shown after closing the clip and in the process of
retracting according to one embodiment of the present
invention.
[0071] FIG. 13 is a top, sectional view of a distal end assembly of
a surgical device in the process of advancing a clip, according to
one embodiment of the present invention.
[0072] FIG. 14 is a transverse sectional view of a portion of a
distal end assembly of a surgical device, according to one
embodiment of the present invention.
[0073] FIG. 15 is a side, sectional view of a distal end assembly
of a surgical device in the process of dispensing a clip from a
retainer of the device into a nose piece of the device, according
to one embodiment of the present invention.
[0074] FIG. 16 is a side, sectional view of a portion of a distal
end assembly of a surgical device showing multiple clips in the
retainer of the device, according to one embodiment of the present
invention.
[0075] FIG. 17 is a side view of the inside of the shaft of a
distal end assembly of a surgical device showing a longitudinally
stacked clip design, according to one embodiment of the present
invention.
[0076] FIG. 18 is a side view of the inside of the shaft of a
distal end assembly of a surgical device showing a longitudinally
stacked clip design, according to one embodiment of the present
invention.
[0077] FIG. 19 is a perspective view of the inside of the shaft of
a distal end assembly of a surgical device showing a longitudinally
stacked clip design, according to one embodiment of the present
invention.
[0078] FIG. 20 is a perspective view of a distal end assembly of a
surgical device showing a transversely stacked clip design,
according to one embodiment of the present invention.
[0079] FIG. 21 is a side, sectional view of a distal end assembly
of a surgical device showing a transversely stacked clip design,
according to one embodiment of the present invention.
[0080] FIG. 22 is a perspective view of the inside of the shaft of
a distal end assembly of a surgical device showing a transversely
stacked clip design, according to one embodiment of the present
invention.
[0081] FIG. 23 is a perspective view of a distal end assembly of a
surgical device showing a clip crimping feature of the device,
according to one embodiment of the present invention.
[0082] FIG. 24 is a side view of a distal end assembly of a
surgical device showing a tether cutting feature of the device,
according to one embodiment of the present invention.
[0083] FIGS. 25 and 26 illustrate a surgical device employing the
clip advance and deployment mechanism of FIGS. 11-24 together with
a tether tensioning mechanism.
DETAILED DESCRIPTION OF THE INVENTION
[0084] Generally, the present invention provides methods and
devices for repairing a heart valve, such as the mitral valve, to
treat heart valve regurgitation or insufficiency. Although the
following description focuses on the treatment of mitral valves,
various embodiments may be used to treat other cardiovascular
valves, such as tricuspid, aortic and/or pulmonary valves.
Furthermore, various embodiments of devices and methods of the
invention may be used in open heart surgical procedures, minimally
invasive surgical procedures, or both. Although minimally invasive
valve repair may be advantageous in some circumstances, in other
cases it may be advantageous to perform an open procedure. If the
heart is to be stopped, for example, it may be advantageous to
perform an open procedure to reduce the amount of time the patient
is placed on cardiopulmonary bypass. The devices and methods of the
invention themselves may also reduce the overall duration of a
valve repair procedure, thus reducing the time the patient is on
cardiopulmonary bypass.
[0085] Generally, devices and methods of the invention involve
coupling one or more devices with a valve annulus and using the
devices to reduce the circumference of the annulus to reduce valve
regurgitation. In some embodiments, methods involve securing a
flexible cord about at least a portion of the annulus of the valve
and cinching the flexible cord to reduce the annular circumference.
Some embodiments, for example, involve placing multiple tethered
anchoring devices into the mitral valve annulus. The tether is then
tightened, applying force to the anchoring devices, to reduce the
circumference of the mitral valve annulus. In some embodiments,
clips may be crimped to reduce the annular circumference. Such
crimping clips may be used with or without a tether in various
embodiments. In other embodiments, a tethering device such as a
rotatory cord may be applied to a valve annulus to tighten the
annulus. Other embodiments may involve one or more other suitable
techniques. Therefore, the following description is provided for
descriptive purposes only and should not be interpreted to limit
the scope of the invention as set forth in the claims.
[0086] Referring now to FIG. 1, a patient 10 undergoing valve
repair according to various embodiments of the invention may
require neither cardiopulmonary bypass nor a large skin incision.
In other embodiments, an open heart surgical procedure,
cardiopulmonary bypass or both may be employed. In some
embodiments, an endotracheal tube may be used to ventilate patient
10 (not shown) while allowing the patient's left lung to collapse
to allow better access to the heart. A small incision 14 may be
made in the left thorax of the patient, to admit a mitral valve
repair device 16. In one embodiment, for example, an incision of
between about 0.5 and about 5 inches, and preferably between about
1 and about 3 inches, may be made in the fifth intercostal space of
patient 10. Any other minimally invasive incisions may
alternatively be used in various embodiments. In other embodiments,
any suitable open heart surgical incisions and procedures may be
used, either on a beating heart or on a stopped heart using
cardiopulmonary bypass. Alternatively, some devices and methods may
be used intravascularly.
[0087] At any suitable time before or during a mitral valve repair
procedure, an imaging device may be placed in or on the patient to
monitor the progress of the procedure. For example, in some
embodiments a 3-dimensional, transesophageal echocardiogram device
and/or a fluoroscopic C-arm may be used for visualization. After a
skin incision is made, one or more various devices may then be used
to navigate a path between the skin incision and the patient's
heart. For example, an imaging devices such as an angioscope, as
well as cutting and/or suturing devices may be used. Cutting and/or
suturing devices may then be used to make a small incision in the
left atrium, for example at the left atrial appendage. In one
embodiment, an incision and a purse string suture will be used to
gain access to the left atrium. Any suitable access methods or
devices may be used, however, to gain surgical access to the mitral
valve (or other valve to be repaired). As noted briefly above,
methods of the present invention may typically be performed on a
beating heart, thus eliminating the need for cardiopulmonary
bypass. It is contemplated, however, that many embodiments will
also be suitable for use in open-heart surgery techniques and/or in
conjunction with use of cardiopulmonary bypass.
[0088] In some embodiments, repair device 16 will then be advanced
into the left atrium through the incision, purse string suture, or
other access site. In other embodiments, as described further
below, an instrument introduction device may be inserted into the
incision in the heart wall and may be secured to the wall, such as
with suture material. At or near the distal end of repair device
16, one or more repair actuators (not shown in FIG. 1) will be used
to repair the mitral valve. For example, in various embodiments,
repair actuators may include a device for applying a cord to a
valve annulus, such as a rotatory device for applying a cord such
as a suture or Teflon strip. A repair actuator may also include a
suture cutter, a suture tightening device, a clip application
device, a fastener application device, an imaging device, or any
other suitable device or combination thereof.
[0089] In many embodiments, the repair actuators will be generally
configured to attach one or more fasteners to the mitral valve
annulus and to tighten the fasteners to cinch, or tighten, the
mitral valve annulus, thus decreasing the overall circumference of
the mitral valve and reducing mitral regurgitation. In other
embodiments, however, a fastener or other device may be placed
across the valve, a device may be placed to bolster or increase the
bulk of the valve annulus, or the like. Therefore, the invention is
in no way limited to including fasteners, sutures, or the like.
[0090] Referring now to FIG. 2A, repair device 16 is shown in
relation to a cross-section of a heart 20. Heart 20 is viewed from
the perspective of the base of the heart (roughly, the top or
cephalic part of the heart), as if the right and left atria were
removed. The pulmonary 26, aortic 28, tricuspid 24 and mitral 22
valves are shown, as well as the mitral valve annulus 21 and the
anterior commisure 23 and posterior commisure 25 of mitral valve
22.
[0091] Repair device 16 suitably includes an elongate shaft 32, a
proximal actuator 27, and several distal repair actuators. In one
embodiment, as shown more clearly in FIG. 2B, repair actuators
include a clip applicator 31, a series of clips 34 connected by a
tether 36, a rivet 35 also connected to tether 36, and a rivet
holder 37. As already discussed, repair device 16 may include more,
fewer, or different distal repair actuators in various embodiments,
without departing from the scope of the invention. Further
discussion of the distal features of one embodiment of repair
device 16 are discussed further below in relation to FIGS. 11-25.
Furthermore, any parts of repair device or devices to be used in
mitral valve repair may be made radiopaque to facilitate
imaging.
[0092] As shown in FIG. 2B, elongate shaft 32 may include a bent or
otherwise shaped portion near its distal end. Repair device 16 may
also comprise any suitable means for applying clips 34, such as
clip applicator 31 in the form of an adjustable jaw. In some
embodiments, elongate shaft 32 includes a lumen for containing
clips 34, tether 36 and/or other elements for applying or cinching
clips 34 or the like.
[0093] Referring now to FIG. 2C, repair device 16 may generally be
configured to hold a plurality of clips 34, for example within
shaft 32. In some embodiments, for example, clips 34 may be housed
in a cartridge-like configuration which may fit within elongate
shaft 32. Clips 34 may be made of any suitable material, such as
Nitinol.TM. (NiTi), stainless steel, titanium, or the like.
Additionally, clips 34 may have any suitable configuration and size
for attaching to a portion of the mitral valve such as the mitral
valve annulus. Although V-shaped, hinged clips 36 with prongs are
shown, U-shaped clips, T-shaped clips, multiply-bent clips,
straight clips and/or the like may be used in various embodiments.
In some embodiments, at least the most distal clip 34n, typically a
first clip to be placed in valve annulus 21, may be coupled with an
end of tether 36. More than one clip may be coupled as well, in
various embodiments. Coupling of one or more clips 34 with tether
36 may be accomplished by any suitable means. In one embodiment,
for example, a radiopaque tether anchor 39 is used to anchor tether
36 to a first clip 34. In other embodiments, attachment may be made
with adhesive, solder, knotting of the tether or the like.
Subsequent clips 34 are then typically suspended on tether 36. The
clips 34 may be attached to tether 36 of may be freely suspended
thereon.
[0094] In some embodiments, clips 34 will be configured as
double-clips or crimping clips. Such crimping clips, for example
may be configured similarly to two V-shaped clips, connected
together at the bottom of the V. Each crimping clip may be attached
to valve annulus tissue at two locations, adjacent to one another,
and the clip may be crimped, to squeeze, pinch, or pleat annular
tissue within the clip. Thus, multiple crimping clips may be
applied circumferentially to an annulus to crimp, or tighten,
tissue along the annulus, thereby tightening the annulus and
reducing regurgitation. In some embodiments, such crimping clips
will be used without a tether, while in other embodiments they will
be coupled with a tether to provide for further annulus tightening.
As with clips 34 described above, such crimping clips may have any
suitable size, shape and configuration and are not limited to
V-shaped double clips.
[0095] Tether 36 generally runs between a first clip 34, or a
device coupled with first clip 34, through each of a plurality of
subsequent clips 34, to rivet 35. Tether 36 may be coupled with
each clip by any suitable means. For example, in FIG. 2B tether 36
runs through a hole or eye in each clip 34. In other embodiments,
tether 36 may be tied, attached with adhesive, wrapped, or
otherwise attached to each clip. Generally, repair device 16 will
be configured to place successive clips 34 along a mitral valve
annulus 21, attaching each clip 34 to the annulus, for example by
using clip applicator 31. Thus, after one clip 34 is attached,
another clip 34 will be fed or will naturally fall or otherwise be
positioned within clip applicator 31 for application to the valve
annulus.
[0096] Tether 36, which couples clips 34 and rivet 35 together may
be any suitable substance for coupling and/or tightening multiple
fastening devices. For example, in some embodiments tether 36 will
be conventional, durable suture material, having a diameter between
about 1 mm and about 3 mm, and preferably about 2 mm. In other
embodiments, a pre-shaped Teflon strip having a diameter between
about 1 mm and about 6 mm, and preferably between about 2 mm and
about 5 mm, may be used. Those skilled in the art will recognize
that any suitable suturing, coupling, tensioning or similar devices
may be used to tether and/or add tension between clips 34.
[0097] With continued reference to FIG. 2C, in some embodiments, a
second tether anchor is coupled with tether 36 and clips 34 to
better allow tether to be cinched. In one embodiment, second tether
anchor comprises a rivet 35, or multiple rivets 35. Rivet 35 is
positioned near the proximal end of clips 34, while first tether
anchor 39 is positioned near the distal end. Rivet 35, for example,
may include a hollow bore, through which tether 36 runs, and may be
positioned to fit within one or more proximal clips 34a-b. In some
embodiments, crimping proximal clips 34a-b to attach them to a
valve annulus will also close the clips 34a-b around rivet 35 to
secure rivet 35 to tether. For example, in one embodiment all clips
34 other than proximal clips 34a-b will be secured to a valve
annulus. Tether 36 will then be cinched, by applying tensile force
to tether 36 in a proximal direction (arrows). Once a desired
amount of cinching force is achieved, proximal clips 34a-b may be
crimped to secure tether 36 within rivet 35 and to secure proximal
clips 34a-b over rivet 35 and to the valve annulus. In various
embodiments, rivet 35 may be preloaded or pre-inserted into one or
more proximal clips 34a-b. In other embodiments, rivet 35 may be
moved into contact with proximal clip(s) 34a-b, by an advancing
device or the like. In still other embodiments, any suitable rivet
holder 37 may be used to hold and place rivet 35 to allow rivet 35
to act as a tether anchor. In one embodiment, for example rivet
holder 37 may be a simple arm-like device. In other embodiments,
rivet holder 37 may be a forceps-like device used to place and
release rivet 35 at a desired location.
[0098] Generally, tether 36 may be coupled with each clip 34 or
other attachment device, and with rivet 35, and one end of tether
36 then runs proximally back towards proximal actuator 27. In one
embodiment, an end of tether 36 runs through shaft 32 of repair
device 16 to a location at or near handle, so that a surgeon or
other physician using the device may use the tether 36 to apply
force or tension to clips 34, rivet 35 and the like. In other
embodiments, other suitable tethering and/or tightening devices may
be used.
[0099] With reference to FIG. 8, another embodiment of a clip 100
and tether 104 is shown. In some embodiments, clips 100 may include
two or more eyelets 102, rather than only one eyelet. In such
embodiments, tether 104 may run through both eyelets on each clip
100. In one embodiment, tether 104 runs through one eyelet 102 of
each clip 100, forms a loop around the far end of the first (or
most distal) clip 100a, and a parallel segment then runs back
through the other eyelet 102 of each clip 100. In some versions,
both ends of tether 104 may then be pulled proximally to cinch the
tethered clips 100. In general, tethering each clip through two or
more eyelets may be advantageously stronger and more durable that
tethering each clip through one eyelet. In alternative embodiments,
various forms of securing devices may also be used, such as a
washer or dowel-like securing device around tether to run through
eyelets 102 of the first clip 100a. Furthermore, tether 104 may be
secured at or around a first clip 100a or other clips via any
suitable means. For example, two tethers may be tied distal to the
first clip 100a or the like.
[0100] With reference now to FIGS. 10A-10B, some embodiments
include one or more crimping clips 120. Crimping clips 120 may be
used in some embodiments with tethers 124 and in other embodiments
without tethers. In some embodiments, for example, a tether 124 may
run through two eyelets 122 on each crimping clip 120. In an
uncrimped clip 120, as shown in FIG. 10A, tether 124 passes
relatively freely through eyelets 122. Thus, for example, tether
124 may be pulled through eyelets 122 of the uncrimped clip 120 to
cinch multiple clips to help reduce the diameter of the valve
annulus. When desired, such as after cinching, clip 120 can be
crimped, as shown in FIG. 10B. Crimping clip 120 involves
deflecting eyelets 122 is some way so as to reduce their inner
diameter. In some embodiments, for example, a surgical device for
placing crimping clips 120 includes a pusher, bar or other device
for pressing a portion of clip 120 to depress or deflect eyelets
122. When the inner diameter of eyelets 122 is reduced, the eyelets
122 will tend to trap or secure tether 124 inside the inner
diameter, thus securing tether 124 in place. Thus, crimping clips
120 may be secured to a valve annulus and further secured to tether
124 via crimping. Many other suitable configurations, shapes, sizes
and the like are contemplated for crimping clips other than those
shown in FIGS. 10A-10B.
[0101] Referring again to FIG. 2A, proximal actuator 27 of repair
device 16 generally includes any suitable device (or devices) for
manipulating and actuating the distal repair actuators. Proximal
actuator 27 generally allows a surgeon or other physician to
manipulate repair device 16 and activate one or more of the distal
features to perform a procedure. In one embodiment, proximal
actuator 27 includes two or more gripper devices that act like a
scissor mechanism. Alternatively, other proximal actuators 27 may
include a trigger, a handle, a plunger, a squeeze-activated device,
a syringe-grip device and/or any other device for moving and
activating distal features/actuators of device 16. In some
embodiments, proximal actuator 27 may include a tether holder,
tether cinching means, a clip adjuster, attachment for an imaging
device and/or the like.
[0102] Referring to FIG. 9, for example, an alternative embodiment
of a surgical device 110 is shown, having a distal end with means
for applying a clip 100 and a proximal end comprising a handle 113
and a trigger 112. Trigger 112 may be moved proximally (arrow) to
perform a function, such as advancing and/or applying a clip 100.
Alternatively, trigger 112 and handle may be replaced by a thumb-
or finger-activated plunger device, a syringe-grip type device, a
squeeze-activated device, or any other device or combination.
Generally, any suitable proximal actuator is contemplated.
[0103] Referring now to FIG. 3A, a repair device 16 is shown
applying clips 34 to a mitral valve annulus 21. In some
embodiments, a first clip 34 may be placed and attached to the
valve annulus 21 at or near the anterior commisure 23 and
subsequent clips may be placed and attached in a direction moving
along the annulus 21 towards the posterior commisure 25. In other
embodiments, it may be advantageous to start at or near the
posterior commisure 25 and move towards the anterior commisure 23.
In still other embodiments, clips 34 may be started at a location
apart from either commisure.
[0104] FIG. 3B shows the same mitral valve with clips in place and
attached to the mitral valve annulus 21 from the anterior commisure
23 to the posterior commisure 25. Furthermore, the clips 34 are
coupled with tether 36 and rivet 35 is coupled to clips 34 via
tether 36. One end of tether 36 is shown exiting the mitral annulus
21, clips 34, and rivet 35. Typically, this free end of tether 36
would be contained within repair device 16 and would be accessible
for use in applying tensile force to tether 36 in a proximal
direction (arrows). For example, as explained above, the free end
of tether 36 may run through repair device to a location outside
patient 10, to allow a physician to apply tension to tether 36.
[0105] In FIG. 3C, tether 36 has been used to apply tension
(arrows) to and between clips 34 to apply force to mitral annulus
21. The force generated will generally be inwardly directed force,
towards the center of the mitral valve 22, as is shown by arrows A.
This force will also tend to pull clips 34 towards one another,
causing the circumference of the mitral valve 22 to decrease and,
thus, helping to decrease mitral regurgitation. As mentioned above,
in some embodiments it is possible to crimp one or more clips 34
before applying tension to tether 36. Crimping may more securely
attach a clip 34 to the annulus, may secure a clip 34 to tether 36,
or both.
[0106] When the methods of the present invention are performed on
beating hearts, either in minimally invasive procedures through
ports or otherwise as described herein, or via an intravascular
(closed chest) approach, it will be desirable to be able to
stabilize and/or locate the valve annulus. It is important that the
clips be applied to the fibrous tissue of the annulus and in
particular that they not be delivered into the leaflet tissue or
the tissue of the atrial wall, neither of which will provide the
desired purchase for holding the clip. An exemplary method for
achieving such stabilization utilizes a clamping device, such as
device 200 illustrated in FIG. 3D. Clamping device 200 includes an
upper or atrial ring 202 and a lower or ventricular ring 204,
typically adapted for placement above and below the annulus of the
mitral valve. The rings 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 rings could be formed from an inflatable or other structure can
be selectively rigidized in situ, such as a gooseneck or lockable
element shaft.
[0107] The device 200 will be introduced to the left atrium of a
beating heart, either transeptally or through an incision in the
heart wall, as described hereinafter in connection with the clip
appliers of the present invention. Once in the atrium, the lower or
ventricular ring will be introduced through the mitral valve
opening, with a corner 206 of the ring typically being engaged
against a commisure. The ventricular ring 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. 3E. The upper or atrial
ring 202 may then be clamped down onto the upper surface of the
annulus VA, typically by sliding an outer shaft 210 down over an
inner shaft 212. Thus, the annulus will be circumferentially
clamped between the rings, again as observed in FIG. 3E. Such
clamping will stabilize the annulus relative to the remainder of
the beating heart, thus facilitating subsequent clip application.
For example, the clip appliers described elsewhere herein may be
used to introduce individual clips 156, as illustrated in FIG. 3F.
Alternatively, the atrial stabilization ring 202 could be replaced
with a circular clip applier 220, as shown in FIG. 3G. A
stabilization 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.
[0108] Although not illustrated, in some instances it may be
desirable to provide a third stabilization element on the exterior
of the heart, optionally between the coronary sinus CS and
circumflex artery CF or within the coronary sinus.
[0109] With reference now to FIG. 4A, some embodiments of the
invention include an instrument introduction device 48 for
facilitating introduction and manipulation of one or more
instruments through a heart wall to perform a surgical procedure on
a heart valve. In some embodiments, such a device 48 includes an
outer surface 52, an inner surface 54, a hollow member 56 coupled
between the surfaces and a valve 50 coupled with hollow member 56.
Generally, device 48 may have any suitable size and configuration
and may be made of any suitable material or combination of
materials. Device 48 is typically placed through a small incision
on a heart wall, such that hollow member 56 is disposed within the
heart wall, outer surface 52 is disposed on the outer surface of
the heart wall, and inner surface 54 is disposed on the inner
surface of the heart wall. Valve 50 comprises a one-way valve which
allows one or more instruments to be introduced through device 48
into a heart chamber but which prevents blood from escaping out of
the heart chamber through valve 50.
[0110] Referring now to FIG. 4B, instrument introduction device 48
is shown within a section of a heart wall 60 and with a surgical
instrument 58 extending through valve 50 and hollow member 56. In
some embodiments, device 48 may be removably attached to heart wall
60 by a surgeon, for example by a purse-string suture or other
means. Generally, device 48 not only protects against blood loss
during a surgical procedure but also reduces trauma to heart wall
60 from manipulation of surgical instruments 58. Thus, device 48
and its various component parts may have any configuration, size
and the like for achieving such effects in a heart valve surgery
and any suitable configuration is contemplated. A suitable
introduction device is described in co-pending application
60/462,502, the full disclosure of which is incorporated herein by
reference.
[0111] With reference now to FIG. 5A, a heart 40 is shown from a
left, side view, showing the outer surface of the left ventricle 44
and the atrium 42. As shown, many methods of the invention may be
performed via a minimally invasive incision 46 in the left atrial
wall. In some embodiments, as described above and as shown in FIG.
5B, instrument introduction device 48 may be placed through the
incision 46, into a position within the wall of the heart. Once
device 48 is in place, one or more surgical instruments 58 may be
placed through device 48 to perform a surgical procedure. In fact,
multiple instruments 58 may be used one at a time, introducing each
instrument through device 48 in some embodiments.
[0112] With reference now to FIG. 6, one embodiment of a device 62
for performing minimally invasive heart valve repair suitably
includes a thin, tubular, handheld shaft 72, coupled at its
proximal end with a connector 74 which in turn is coupled with an
actuator 76. Shaft 72 may have any suitable shape, size and
configuration to allow convenient manipulation of device 62 by a
surgeon to perform a surgical valve procedure. In one embodiment,
for example, shaft 72 is shaped like a thin wand or pencil-like
apparatus which may be held and manipulated with one hand of a
surgeon and may be inserted into a chamber of the heart through a
small, minimally invasive incision or introduction device. Shaft 72
will typically be used to place and secure one or more tethering
clips 70 or other tethering devices in a valve annulus, such as the
mitral valve annulus, and may also be used to cinch connected
tethering devices to tighten the valve. In one embodiment, a cable
75 runs longitudinally through all or a part of shaft 72 and
continues through connector 74 or a similar housing to actuator 76.
Actuator 76 may then act through cable 75 to advance clips 70
through shaft 72 and/or to apply clips 70 to a valve annulus or
other area on or around a valve. Thus, a device 62 as shown in FIG.
6 may include shaft 72 for manipulating and positioning with one
hand of a surgeon and a coupled actuator 76 for use by the other
hand of the surgeon or by another person, such as an assistant. A
thin shaft 72 will typically be easy to manipulate and position, to
enhance the accuracy and convenience valve surgery procedures.
[0113] With reference now to FIG. 7A, a surgical device 80 for
surgically treating a heart valve may suitably include an
ultrasound transducer 82 at or near the distal end of the device
for enhancing visualization of a valve annulus 83, other surgical
site, surgical instruments and/or the like. For example, ultrasound
transducer 82 may comprise a distal tip which may be removably or
permanently attached to the distal end of surgical device 80. The
embodiment in FIG. 7A also includes multiple rivets 81, which may
be included to further enhance coupling of the tether and clips. In
another embodiment, ultrasound transducer 82 may be coupled with
device 80 near the distal end at a different location, may be
permanently integrated into device 80 and/or the like. Any suitable
ultrasound transducer 82 may be used.
[0114] In another embodiment, and with reference now to FIG. 7B,
visualization of a heart valve surgical site and heart valve
procedure may be enhanced by use of a conventional ultrasound
transducer 84 coupled with a gel-filled or fluid-filled cone 86.
Cone 86 may have any suitable shape, size and overall configuration
and may be filled, or partially filled, with any suitable gel or
fluid for enhancing transmission of ultrasound signals from
transducer 84. Generally, transducer 84 and cone 86 may be coupled
together via complementary coupling surfaces 88 or any other
suitable means. Once transducer 84 and cone 86 are coupled, cone 86
may then be used to contact a surface of a heart to begin
ultrasound visualization. The gel or fluid in cone 86 allows for
efficient ultrasound transmission and visualization without
requiring placement of gels or fluids directly onto heart tissue.
Thus, ultrasound transducer 84 may be used to effectively aid
visualization of the heart without introducing unwanted gels,
fluids, or the like into or onto the heart.
[0115] Referring now to FIGS. 7C and 7D, in many instances it will
be preferable to perform some or all of the interventional steps of
the methods of the present invention under direct optical viewing.
One apparatus for performing such direct optical viewing is the
bubble scope 250 illustrated in FIGS. 7C and 7D. The scope 250
includes a sheath 252, an inflatable, optically transparent balloon
254 at a distal end of the sheath, a fiberoptic scope 256, an
inflation tube or lumen 258, a scope seal 260, and an inflation
port 262 open to the interior of the balloon 254. Scope 256 is
advanced distally through a lumen of the sheath 252 so that the
scope extends through the seal 260, as illustrated in FIG. 7D. The
seal around the scope permits inflation of the balloon through the
inflation lumen, with an optically transparent medium entering
through the inflation port 262. The optically transparent balloon
254 is preferably formed from an elastic material so that it can be
engaged against the valve annulus or other interior cardiac surface
and conform against said surface clip applier and other tools used
in performing the methods of the present invention. Once in place
inside the heart chamber, such as the left atrium above the mitral
valve, the balloon 254 may be engaged against a surface to be
treated, against the distal end of the clip applier or both. The
bubble scope 250 may thus be used to initially position the clip
applier, optionally to observe the delivery of the clip, and
finally to observe clip placement to confirm it is proper.
[0116] Referring now to FIG. 11, a distal end 140 of a surgical
stapling device 141 for repair of cardiovascular valves is shown.
As mentioned above, distal end 140 may have any of a variety of
configurations, shapes, sizes, functions and the like in various
embodiments of the invention. The following description, therefore,
is provided for exemplary purposes only, to help describe one
embodiment of a surgical device, and should not be interpreted to
limit the scope of the invention as it is set forth in the
claims.
[0117] That being said, and with reference now to FIG. 11A, one
embodiment of a distal end assembly 140 suitably includes a distal
end portion of shaft 142, an anvil 144, a tether 146 having
parallel segments 146a and 146b, a nose piece 148, guide slots 150,
a staple mandrel 152, a leaf spring 154, one or more staples 156,
and a retainer belt 158. Again, other embodiments may include fewer
or additional elements. Also, for the purposes of this description
the terms "staple" and "clip" are interchangeable and generally
refer to any fastener, anchor, or piece that may be attached to a
valve. Generally, the features shown in FIG. 11A may be used to
apply a plurality of staples 156, tethered with one or more tethers
or cables 146, to a valve annulus. Tether 146 may include but is
not limited to a strip, band, filament, wire, strap or any other
connective element. In one embodiment, staples 156 are applied
along the annulus of the a heart valve. One or more tethers 146 is
pre-threaded through the eyelet (or eyelets) of each staple 156 and
runs from the distal end assembly of device 140 to the its proximal
end.
[0118] Once staples 156 are secured to the tissue, tether 146 is
pulled from the proximal end of device 140 to cinch staples 156 and
thereby reduce the annular diameter. Tension may be adjusted on
tether 146 while using ultrasound Doppler flow guidance or direct
visualization in real time to allow the annulus to expand for
precise adjustment of the annular correction. After an optimal size
of the annulus is achieved, one or more final staples are dispensed
and crimped (using crimp bar 184 described with reference to FIG.
20) by the device. This step locks the tether 146 tension by
securing the tether 146 to the final staple(s) 156. The tether 146
is then cut at the point beyond the last staple by a sliding blade
190 (FIG. 20) within the device or by any other suitable means.
Shaft 142, with nose piece 148 and guide slots 15, acts to
longitudinally guide staples 156 toward the distal end assembly of
device 140 to be applied to a valve annulus. Anvil 144 pushes
staples 156 forward/distally to be dispensed.
[0119] Referring now to FIG. 12, a perspective view of distal end
assembly 140 is shown in the process of closing a clip 156, with
anvil 144 pushing clip 156 forward. FIG. 12A then shows distal end
assembly 142 after clip 156 is closed, with anvil 144 in the
process of retracting. Generally, guide slots (not shown) along the
length of the surgical device are continuous with the ramps and
guide slots 150 in nose piece 148. In operation, a user activates
an proximal actuator (not shown) which drives a ratchet to rotate
retainer belt 158 (FIG. 15) such that a surface containing the set
of staples translates distally. This activation of actuator also
pushes anvil 144 distally.
[0120] Referring now to FIGS. 13 and 13A, retainer bumps 160 on
retainer belt 158 contact generally fit around staples 156 and
function to keep staples 156 in position while moving the staples
distally. As the belt advances during the actuation process,
staples 156 are guided forward by the guide slots 150 on each side
of the inner diameter of the devices guide shaft 157.
[0121] Referring to FIG. 15, the most distal staple 156 moves to
the distal end, up a ramp 162, and is dispensed into guide slots
150 in nose piece 148 which are in continuity with the ramp and the
guide slots in the device shaft.
[0122] Once the distal staple 156 is moved into nose piece 148,
anvil 144 moves forward (or distally) to move staple 156 distally
until it bumps against staple mandrel 152 on the distal end of nose
piece 148 (FIG. 11A). Leaf spring 154 generally pushes upward level
with the top of staple mandrel 152, but when an unclosed staple
slides over them, leaf springs 154 are deflected downward away from
the top of staple mandrel 152. Staple 156 is retained within the
plane of guide slots 150 in nose piece 148. In one embodiment, the
inner surface of the distal end of anvil 144 is U shaped and the
inner surfaces of the lateral prongs are curved outward. These
outwardly curved lateral prongs act as ramps for the
proximal-lateral aspect of staple 156. As anvil 144 is advanced,
the prongs can ramp over the lateral surfaces of the staple legs
distally as well as inwardly (FIGS. 12 and 12A). The prongs bend
the outer staple legs around the staple mandrel resulting in a
closed staple as shown in FIGS. 12 and 12A. Once staple 156 is
closed, its lateral surfaces are not captured by the outside guide
slot so it is and the staple is free to translate move
transversely. As shown in FIG. 12A, anvil 144 retracts when an
actuation lever is released, and the leaf springs push staple 156
up and out over staple mandrel 152.
[0123] In one embodiment, as shown in FIGS. 17-19, staples 156 are
stacked longitudinally inside shaft 142. A compression spring 166
pushes on a compression bloc 164 to advance staples 156 forward as
they are dispensed. The most distal staple 156 is pushed through a
staple dispensing opening 170 (FIG. 18) by a staple dispensing push
plate 168.
[0124] In another embodiment, as shown in FIGS. 20-22, staples 156
are stacked transversely. Staple guide slots 150 in the nose piece
148 allow one staple 156 to be pushed from the staple stack at a
time. As the staples are used up, the stack decreases in height. A
staple stack spring 180 maintains staples 156 in position. Tether
146 is threaded through the eyelets of staples 156 and wraps around
a cable pulley 182 so it can slide freely longitudinally as well as
transversely through the stack of staples 156. Free cable motion is
important for making fine adjustments of cable tension through
staples 156 once they have been delivered to tissue. The free
sliding of the cables through the undispensed staples also allows
for newly dispensed staples to slide freely in position to be
stapled to the tissue.
[0125] Referring now to FIG. 23, after staples 156 other than one
or more final staples have been secured to tissue and cable tension
and position have been adjusted (if necessary), one or more final
staples 156 are then dispensed and stapled to the tissue. In
addition to bending the legs of the final staples 156 inward to
secure the final staples 156 to annulus tissue, in one embodiment
the eyelets of the final staples are crimped down to secure cable
146 to the final staples 156. This crimping may be achieved by a
crimp bar 184, as shown in FIG. 23, which may be advanced forward
(distally) to apply pressure against eyelets 186 (or "holes") of a
clip. The pressure applied by crimp bar 184 closes eyelets 186 to a
degree sufficient to secure tether 146 within eyelets 186, thus
securing staple 156 to tether. In some embodiments, crimp bar 184
is fitted within a central slot in anvil 144. In closing the legs
of non-termination staples, crimp bar 184 is retracted in the
central slot. To attach a final staples 156, a user activates a
proximal actuator which drives crimp bar 184 to protrude forward.
Alternatively, the switch may also be self-activated by the device
when the final staple (or staples) is ready to be secured to
tissue. When anvil 144 advances to close the legs, the protruding
crimp bar 184 presses staple eyelets 186 against the staple mandrel
to crimp it tight on the cable to lock the cable to the staple.
[0126] With reference now to FIG. 24, some embodiments of the
device include a cable cutter 190 for cutting tether or cable
146--once it is cinched to reduce the diameter of the valve. In
some embodiments, once the final staple 156 is applied, tension is
applied to cable and staple eyelets are crimped, a switch (e.g.,
crank 304 in FIG. 25) is activated to drive a spring loaded tether
cutter 190 forward to cut cable 146. In other embodiments, a user
may manually activate cutter 190. Generally, any suitable means for
cutting cable 146 may be used in the present invention.
[0127] The various features of distal end assembly 140 described
above may be made from any suitable materials and combinations of
materials. For example, nose piece 148 and housing 142, in one
embodiment, may be made from materials such as but not limited to
stiff polymers such as polycarbonate, nylon, acrylonitrile
butadiene styrene (ABS), polypropylene, PEEK, PVDF or urethane. In
another embodiment, nose piece 148 may be made from one or more
stainless steel materials such as 17-4, 304, or 316 steel. Staple
mandrel 152, anvil 144, crimp bar 184, and cutter 190 in one
embodiment are made from a hard stainless steel such as hardened
17-4 steel and/or 440 steel. Alternatively, these features may be
made from tungsten carbide or any other suitable material, such as
softer stainless steels coated with titanium nitride to increase
surface hardness. Leaf springs 154 and compression springs 166 in
one embodiment may be made from a polymer like PEEK, nickel
titanium, or stainless steel, but other materials may alternatively
be used. Staple retainer belt 158 may be made out of flexible
polymers such as high flex PVDF, PTFE, nylons, polyethylene,
polyurethane, polyester, isoprene, silicones and/or the like.
Generally, any of these materials, combinations of these materials,
or any other suitable materials or combinations not mentioned here
may be used to manufacture one or more of the elements of a
surgical device for repairing cardiovascular valves according to
the invention.
[0128] An exemplary stapling device 141 is illustrated in FIG. 25
where the shaft 142 is connected to a pistol grip handle assembly
300. The assembly 300 includes a trigger 302 for advancing and
deploying individual clips 156 and optionally a crank 304 for
actuating the tether cutter 190 (FIG. 24). Of particular interest,
a tether tensioning mechanism 310 may be provided to take-up the
tether segments 146a and 146b, as best seen in FIG. 26. The
tensioning mechanism includes a spool 312 which is mounted to spin
freely to release tether 146 as the device dispenses the tether as
the staples 156 are deployed. When desired, however, the mechanism
can be switched to permit the tether 146 to be "reeled" back over
the spool 312 to pull back and tension the deployed tether, i.e.,
to apply a constricting force to the staples surrounding the valve
annulus. Usually, the mechanism will have a ratchet (not shown) to
assist in manually turning of the spool 312 to reel in the tether,
and optionally the mechanism will include a tension control or
measurement mechanism (not shown). Thus, immediately prior to
crimping a terminal clip, the tether 146 can be cinched to a
preselected tension with the tensioning mechanism.
[0129] Although the foregoing is a complete and accurate
description of the present invention, it should be emphasized that
the description provided above is for exemplary purposes only that
variations may be made to the embodiments described without
departing from the scope of the invention. For example, various
embodiments of the invention may be used to repair a valve other
than the mitral valve, such as the tricuspid valve. In other
embodiments, clips may be eliminated and a rotatory cord such as a
suture alone may be used. Other embodiments may include only a
single, larger clip or fastener. Thus, the above scope of the
invention as described in the appended claims.
* * * * *