U.S. patent application number 12/549989 was filed with the patent office on 2010-02-25 for annuloplasty with enhanced anchoring to the annulus based on tissue healing.
Invention is credited to E. David Kirson.
Application Number | 20100049315 12/549989 |
Document ID | / |
Family ID | 39226072 |
Filed Date | 2010-02-25 |
United States Patent
Application |
20100049315 |
Kind Code |
A1 |
Kirson; E. David |
February 25, 2010 |
ANNULOPLASTY WITH ENHANCED ANCHORING TO THE ANNULUS BASED ON TISSUE
HEALING
Abstract
Methods, delivery systems and engaging apparatuses for the
placement and treatment of an insufficient or stenotic cardiac
valve, such as the mitral valve are disclosed. One such method is
based on a two step procedure, where during the first step the
engaging apparatus is brought to the valve annulus using a delivery
system which permits continued normal blood flow. In some preferred
embodiments, this is implemented with a balloon and other preferred
embodiments it is implemented using a multi-pronged structure that
is collapsible like an umbrella frame. The second step is performed
after the engaging apparatus has been integrated into the annular
wall by natural processes of tissue healing and remodeling. In the
second step the engaging apparatus is tightened leading to
tightening of the valve annulus and correction of existing valvular
insufficiency. Optionally, an artificial valve may be anchored to
the engaging apparatus during the same or subsequent procedure to
correct either valvular insufficiency or stenosis.
Inventors: |
Kirson; E. David;
(Barrington Hills, IL) |
Correspondence
Address: |
PROSKAUER ROSE LLP
One International Place
Boston
MA
02110
US
|
Family ID: |
39226072 |
Appl. No.: |
12/549989 |
Filed: |
August 28, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11837077 |
Aug 10, 2007 |
|
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12549989 |
|
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60822113 |
Aug 11, 2006 |
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Current U.S.
Class: |
623/2.37 |
Current CPC
Class: |
A61F 2220/0008 20130101;
A61F 2250/0059 20130101; A61F 2250/006 20130101; A61F 2250/0004
20130101; A61F 2/2412 20130101; A61F 2/2466 20130101; A61F 2230/008
20130101; A61F 2/2409 20130101; A61F 2/2445 20130101; A61F
2220/0016 20130101; A61F 2/2418 20130101 |
Class at
Publication: |
623/2.37 |
International
Class: |
A61F 2/24 20060101
A61F002/24 |
Claims
1. An apparatus for repairing an annulus comprising: an annulus
contact portion having an outer boundary that is configured for
pressing outwards against the annulus, wherein the annulus contact
portion is substantially arc-shaped and has an inner core; and a
wire that runs through the inner core and is arranged with respect
to the annulus contact portion so that pulling on the wire causes
the outer boundary to contract.
2. The apparatus of claim 1, wherein the annulus contact portion
has a plurality of barbs configured to promote attachment of the
annulus contact portion to the annulus.
3. The apparatus of claim 1, wherein the substantially arc-shaped
annulus contact portion subtends an angle of at least
180.degree..
4. The apparatus of claim 1, wherein the substantially arc-shaped
annulus contact portion subtends an angle of at least
270.degree..
5. The apparatus of claim 1, wherein annulus contact portion
comprises a helical spring that has been formed into an arc.
6. The apparatus of claim 5, wherein the helical spring has an
outer diameter between about 25 and about 60 mm, a helix diameter
between about 1 and about 3 mm, and a helix pitch between about 1
and about 3 mm.
7. The apparatus of claim 5, wherein the annulus contact portion
has a plurality of barbs configured to promote attachment of the
annulus contact portion to the annulus.
8. The apparatus of claim 5, wherein the substantially arc-shaped
annulus contact portion subtends an angle of at least
180.degree..
9. The apparatus of claim 5, wherein the substantially arc-shaped
annulus contact portion subtends an angle of at least
270.degree..
10. An apparatus for repairing an annulus comprising: an annulus
contact portion having an outer boundary that is configured for
pressing outwards against the annulus, wherein the annulus contact
portion is substantially arc-shaped and has an inner core; a wire
that runs through the inner core and is arranged with respect to
the annulus contact portion so that pulling on the wire causes the
outer boundary to contract; and a pressing member configured to
press the annulus contact portion against the annulus while
simultaneously permitting blood to flow therethrough.
11. The apparatus of claim 10, wherein the pressing member
comprises an inflatable balloon configured to be positioned within
the annulus contact portion so that inflation of the balloon cause
the annulus contact portion to press against the annulus, and
wherein the balloon has a channel that permits blood to flow
therethrough when the balloon is inflated.
12. The apparatus of claim 11, wherein annulus contact portion
comprises a helical spring that has been formed into an arc.
13. The apparatus of claim 10, wherein the pressing member
comprises a multi-pronged structure adapted to press the annulus
contact portion against the inner surface of the annulus when
actuated, without blocking off the flow of blood.
14. The apparatus of claim 13, wherein annulus contact portion
comprises a helical spring that has been formed into an arc.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. application Ser.
No. 11/837,077, filed Aug. 10, 2007, which claims the benefit of
U.S. provisional application No. 60/822,113, filed Aug. 11, 2006.
Both of those applications are incorporated herein by
reference.
BACKGROUND
[0002] In the recent past, many advances have been made to reduce
the invasiveness of cardiac surgery. In an attempt to avoid open,
stopped-heart procedures, which may be accompanied by high patient
morbidity and mortality, many devices and methods have been
developed for performing surgery on a heart through smaller
incisions, operating on a beating heart, and finally, in the past
years, performing cardiac procedures via transvascular access.
Significant technological advances have been made in various types
of cardiac procedures, such as cardiac ablation techniques for
treating atrial fibrillation, stenting procedures for
atherosclerosis, and valve repair procedures. More specifically,
much progress has been made on treating conditions such as mitral
valve regurgitation. In implementing many minimally invasive
cardiac surgery techniques, especially beating-heart techniques,
one of the most significant challenges is positioning a treatment
device and once positioned, to effectively deploy and fix a given
device or treatment into or on the surface of the target cardiac
tissue.
[0003] Traditional treatment of heart valve stenosis or
regurgitation, such as mitral or tricuspid regurgitation, typically
involves an open-heart surgical procedure to replace or repair the
valve. Valve repair procedures typically involve annuloplasty, a
set of techniques designed to restore the valve annulus shape and
strengthen the annulus. Conventional annuloplasty surgery generally
requires a thoracotomy, and sometimes a median sternotomy. These
open heart procedures 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
technically challenging and require a relatively large incision
through the wall of the heart to access the valve.
[0004] Due to the highly invasive nature of open heart valve repair
or replacement, high risk patients are usually not candidates for
these procedures and thus are destined to functional deterioration
and cardiac enlargement. Often, such patients have no feasible
alternative treatments for their heart valve conditions.
[0005] In order to try and solve this problem, a number of devices
and methods for repairing cardiac valves in a less invasive manner
have been described. Some devices offer heart valve repair through
minimally invasive incisions or intravascularly, while others
attempt to improve open heart surgical procedures on beating
hearts, stopped hearts or both. Difficulties in performing
minimally invasive intra-cardiac surgery include positioning a
minimally invasive treatment device in a desired location for
performing a procedure and effectively placing and fixing a device
into or on the surface of the target cardiac tissue. In heart valve
repair procedures, for example, it is often essential for a
physician to fix a device to valve annulus tissue. Annular tissue
tends to be more fibrous than surrounding muscular or valve leaflet
tissue, thus providing a more suitable location for securing such a
device. In the past, various types of anchors and anchoring
techniques have been developed in order to fix treatment devices to
the annular tissue. This is an important stage in all annuloplasty
procedures and especially in procedures for treating mitral or
tricuspid valve regurgitation.
[0006] Devices and methods that address these difficulties are
described in U.S. Patent Application Nos. 60/445,890, 60/459,735,
60/462,502, 60/524,622, Ser. No. 10/461,043, Ser. No. 10/656,797
and Ser. No. 10/741,130. For example, these references describe
devices and methods for exposing, stabilizing and/or performing
procedure on a heart valve annulus, such as a mitral valve annulus.
Many of these methods and devices have shown preliminary promise,
however a highly safe and effective method and engaging apparatus
for performing cardiac valve annuloplasty has, until now, been
lacking.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 shows the location of the mitral annulus in a
cross-section of the heart.
[0008] FIG. 2 shows a first approach for positioning a first
embodiment of an engaging apparatus at the annulus.
[0009] FIG. 3 shows a cross section of the embodiment shown in FIG.
2.
[0010] FIG. 4 shows an embodiment of a delivery system in which a
multi-pronged device is used to place the engaging apparatus at the
annulus.
[0011] FIG. 5 shows a close up of the end of the FIG. 4
embodiment.
[0012] FIG. 6 is a detailed view of the first embodiment of the
engaging apparatus.
[0013] FIG. 7 shows a detailed view of another embodiment of the
engaging apparatus.
[0014] FIG. 8 shows the engaging apparatus of FIG. 7 in location at
the mitral annulus immediately after being positioned and anchored
to the tissue.
[0015] FIG. 9 shows the engaging apparatus of FIG. 7 after being
left in place for sufficient time for tissue healing and remodeling
to occur.
[0016] FIG. 10 shows another embodiment of an engaging apparatus
that contains an integral anchoring delivery system.
[0017] FIG. 11 shows the FIG. 10 embodiment with an artificial
valve anchored to the engaging apparatus.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] FIG. 1 shows the location of the mitral annulus 2 in a
cross-section of the heart. The method and engaging apparatus of
the current delivery system are used to facilitate transvascular,
minimally invasive and other "less invasive" surgical procedures,
by facilitating the placing and fixing of a treatment engaging
apparatus 6 at a treatment site. As used herein, "less invasive"
means any procedure that is less invasive than traditional,
large-incision, open surgical procedures. Generally, any procedure
in which a goal is to minimize or reduce invasiveness to the
patient may be considered less invasive. Although the methods
described herein are developed for use in minimally invasive
procedures, they may be applied to performing or enhancing any
suitable procedure, including traditional open heart surgery. The
present application describes methods and apparatuses for
performing heart valve repair or replacement procedures, and more
specifically heart valve annuloplasty procedures such as mitral
valve annuloplasty to treat mitral regurgitation and mitral valve
replacement to treat mitral stenosis. In other embodiments, the
devices and methods may be used to enhance a laparoscopic or other
endoscopic procedure on any part of the body, such as the bladder,
stomach, gastroesophageal junction, vasculature, gall bladder, or
the like. Therefore, although the following description typically
focuses on mitral valve 8 and other heart valve 9 repair, such
description should not be interpreted to limit the scope of the
invention.
[0019] FIG. 2 shows a cross-section of the heart, with a full view
of one embodiment of a balloon delivery system 4 and a full view of
an engaging apparatus 6. The balloon delivery system 4 can be used
for placement of the engaging apparatus 6 at the annulus 2.
Initially, the balloon is routed to the proper position in its
deflated state (not shown) using any suitable route or method
(e.g., an endoscopic technique), and then inflated. At this point,
the system will resemble FIG. 2, in which the balloon 4 is shown in
its inflated state, positioned at the mitral valve 8. The engaging
apparatus 6 is located around the balloon 4, and the inflation
brings the engaging apparatus 6 into proximity of the annular
tissue 2 and presses them towards each other. The engaging
apparatus 6 initially surrounds the balloon 4 and anchors to the
annular tissue 2 upon inflation of the balloon 4.
[0020] FIG. 3 depicts the same items as FIG. 2 except that the
delivery system is shown in cross section. The balloon is shown
with a central channel 10 and flexible leaflets 12 seen within its
lumen. These leaflets 12 act as a temporary replacement valve in
order to allow normal heart function during the insertion
procedure. In some embodiments, valve repair or replacement may be
implemented using a hollow, inflatable balloon 4 with integral
flexible valve leaflets 12 within its lumen which act as a
temporary replacement for the natural valve upon inflation, while
maintaining adequate flow through from the atrium 1 to the
ventricle 3 throughout the procedure via channel 10. Because of the
channel 10, blood can flow through the system even when the balloon
6 is inflated, which facilitates installation of the device into a
beating heart.
[0021] Upon deflation of the balloon, the engaging apparatus 6 will
detach from the balloon 4 and remain attached to the annulus 2 with
enough anchoring force to withstand normal cardiac contraction,
flow and valve movement. Attachment to the annulus can be aided by
using appropriate anchors, hooks, barbs, etc. Alternatively, the
engaging apparatus 6 can hold itself in place by exerting a
centripetal pressure on the annulus, generated by the springiness
of the engaging apparatus.
[0022] In some embodiments (not shown), the engaging apparatus 6
may be contained within a hidden circumferential pocket surrounding
the balloon 4 and will engage the annular tissue 2 only upon
release from this pocket. The release of the engaging apparatus 6
from the balloon 4 may be performed by releasing a slip-knot like
suture from the balloon 4 or any other suitable alternative
approach. In these embodiments, conventional balloon and balloon
inflation technology may be used, similar to those used in other
annuloplasty procedures (e.g., conventional balloon procedures for
widening a stenotic valve).
[0023] FIG. 4 shows a cross-section of the heart, a full view of
the first embodiment of an engaging apparatus 6, and a full view of
the second embodiment of a delivery system. This delivery system
uses a multi-pronged device 14 that is preferably collapsible
(similar to an umbrella frame, a truncated wire whisk, etc). to
place the engaging apparatus 6 at the annulus 2. The methods and
engaging apparatus of the delivery system, however, may be used in
any suitable procedure, both cardiac and non-cardiac. For example,
they may be used in procedures to repair any heart valve 9, to
replace any heart valve 9, to repair an atrial-septal 11 defect, to
access and possibly perform a valve repair from (or through) the
coronary sinus.
[0024] FIG. 5 shows a detail view of the multi-pronged delivery
system 14 shown in FIG. 4. In some embodiments, valve repair may be
implemented using a delivery device 14 which can be extended from
the tip of a catheter 16 to allow for the correct positioning of
the engaging apparatus 6 at the annulus. The multi-pronged
placement device 14 can be introduced into the left atrium 1 (shown
in FIG. 4) during on-pump or off-pump procedures through the wall
of the atrium or through the intra-atrial septum, with the catheter
16 introduced by intravascular or minimal invasive approach.
Placement and tightening may be performed on a beating heart
because blood can flow through the spaces between the prongs.
Access to the beating heart may be accomplished by any available
technique, including intravascular, trans-thoracic, and the like.
Intravascular access to a heart valve may be achieved using any
suitable route or method.
[0025] For example, to perform a procedure on a mitral valve 8 a
catheter 16 may be advanced through a femoral artery, to the aorta,
and into the left ventricle of the heart, to contact a length of
the mitral valve. After it is so positioned, the device 14 is
expanded so as to press the engaging apparatus 6 against the
annulus. The expansion of the delivery system 14 may be implemented
using any suitable technique such as withdrawal of a sheath that
permits the prongs to spring out to their natural state.
Alternatively, access may be gained through the venous delivery
system, to a central vein, into the right atrium of the heart, and
across the inter-atrial septum to the left side of the heart to
contact a length of the mitral valve. In alternative embodiments,
the catheter device 16 may access the coronary sinus and a valve
procedure may be performed directly from the sinus. Furthermore, in
addition to beating heart access, methods of the present delivery
system may be used for intravascular stopped heart access as well
as stopped heart open chest procedures. Any suitable intravascular
or other access method may be substituted.
[0026] FIG. 6 shows a detailed view of the first embodiment of the
engaging apparatus. This embodiment uses a helical spring 18 that
has been formed to be substantially arc-shaped preferably
subtending an arc of at least 180.degree., and more preferably at
least 270.degree., with a wire 20 within it for subsequent
tightening. The spring geometry allows for changes in ring
diameter, and creates a channel for the tightening wire. It also
allows for tissue healing into the spaces in the spring 22, thereby
bonding the engaging apparatus to the annulus wall by embedding the
engaging apparatus within the annulus wall. Some time after the
initial placement, a second procedure for tightening the engaging
apparatus 6 is preferably implemented.
[0027] Tightening of the engaging apparatus may be accomplished,
for example, by retracting a wire 20 left within the engaging
apparatus 6 during its placement at the annulus using a minimally
invasive approach. However, any alternative method or device for
the tightening of a structure at the annulus may be used. This
includes, but is not limited to, different types of steerable
catheter tips 16 (as shown in FIG. 4) catheters allowing for direct
manipulation of objects at the tip, catheters allowing for
visualization of the annulus, and catheters which deliver energy at
the area of interest (ultrasound, heat, radiofrequency fields,
etc.). Non-invasive techniques for tightening the engaging
apparatus 6 may also be used, including but not limited to magnetic
manipulation through the chest wall, radiofrequency energy delivery
through the chest wall and ultrasound energy transmitted through
the chest wall.
[0028] The engaging apparatus 6 may be made of Stainless Steel,
Nitinol, Elgiloy or Titanium; however any material with the
necessary strength, flexibility and biocompatibility to withstand
cardiac pressures may be used. A suitable diameter for the arc is
between about 25 and about 60 mm. A suitable diameter for the helix
is between about 1 and about 3 mm, and a suitable pitch for the
helix is between about 1 and about 3 mm.
[0029] In some embodiments, the engaging apparatus 6 may be
constructed of a spring like ring 18 with or without a central
cavity for a tightening wire 20. This spring like ring 18 may be
configured to facilitate the growth of annular tissue into the
engaging apparatus 6 strengthening the adhesion between the annulus
and the engaging apparatus 6. However, other surface geometries
which facilitate tissue anchoring into the engaging apparatus may
also be used, including but not limited to serrated, hooked, porous
or folded surfaces. A tube with holes or serrations cut therein
(not shown) may also be used.
[0030] In some embodiments, the tightening wire 20 may be made of
silk or plastic, however, any material with sufficient strength,
elasticity and biocompatibility may be used for this purpose. As
used herein, the term "wire" includes all such materials and
constructions. The wire 20 may be used for subsequent tightening of
the engaging apparatus 6 (e.g., by pulling on both ends of the
wire) leading to a tightening of the annulus of the patient's
heart.
[0031] FIG. 7 shows a detailed view of a second embodiment of an
engaging apparatus. This embodiment is similar to the FIG. 6
embodiment discussed above, but anchors 24 are added to the spring
like ring 18 for initial anchoring of the engaging apparatus 56 to
the annulus to better withstand cardiac contraction, valve motion
and blood flow. One type of anchoring element--a two pronged, open
ended miniature spring 26--is shown in the insert A, but
alternative anchors may be used instead. Any of the delivery
systems described above may be used to position the engaging
apparatus 56 at the annulus and fix it in place by gentle
centripetal pressure 4 alone or in conjunction with any existing
placing and anchoring technique or by the use of existing placing
and anchoring techniques alone. Alternatively, the engaging
apparatus 56 may be placed using any other minimally invasive or
invasive placement delivery systems.
[0032] Optionally, any of the engaging apparatuses described herein
may be coated with an adhesive substance to facilitate integration
between the engaging apparatus and the annulus. Optionally, the
engaging apparatus may contain hooks, serrations, spokes or sutures
for preliminary attachment to the annulus. Examples of suitable
structures include, but are not limited to, a closed circular
spring with a flexible diameter, open ended semi-circular
structures, non circular structures capable of approximation
between two or more free tips, and non-continuous structures such
as individual tubes connected to the annular rim. Optionally, the
engaging apparatus may be made of or elute materials which
stimulate or accelerate tissue growth. These materials may include
but are not limited to growth factors, pro-inflammatory agents,
foreign substances which are immunogenic and lead to an enhanced
tissue reaction to the engaging apparatus. Optionally, the engaging
apparatus may contain an active electromechanical element, such as
a motor or actuator, capable of tightening the engaging apparatus.
This active component may be self powered by a battery or by
mechanical energy generated by the cardiac muscle or blood flow.
The active element may be activated using minimally invasive
techniques or non-invasive techniques. In the case of non-invasive
activation of the active element, any form of transmitted energy
may be used, including but not limited to ultrasound and
radiofrequency transmission.
[0033] The delivery systems and engaging apparatuses described
herein may be used for repair of a cardiac valve annulus such as a
mitral valve annulus using a two step procedure: placing and
tightening. The method preferably involves bringing an engaging
apparatus into position to the annulus of interest as shown in FIG.
2 or FIG. 4 through a minimally invasive procedure.
[0034] FIG. 8 shows the engaging apparatus 56 from FIG. 7 in
location at the mitral annulus 2 immediately after being left in
place and anchored to the tissue using the delivery system
described above or any other minimally invasive or invasive
placement delivery system. No tissue healing or remodeling has
occurred at this stage and the engaging apparatus 6 is attached to
the annulus 2 with the minimal necessary force.
[0035] FIG. 9 shows the same engaging apparatus 56 after being left
in place for sufficient time for tissue healing and remodeling to
occur 28. At this point the engaging apparatus 56 is integrated
into the annulus 2 due to tissue healing which has embedded the
engaging apparatus within the annular wall. This tissue healing 28
embeds the engaging apparatus 56 within the wall of the annulus 2
with sufficient integration to allow for subsequent tightening of
the engaging apparatus 56 (e.g., by pulling on both ends of the
wire 20, shown in FIG. 7) to circumferentially tighten the annulus
2. The anchoring strength of the engaging apparatus to the annulus
at this stage is preferably sufficient to withstand tightening of
the engaging apparatus 56 and the entire annulus 2 in a subsequent
procedure.
[0036] By using this procedure (i.e., install, wait for
incorporation, then tighten), the initial placement of the engaging
apparatus 56 at the annulus 2 requires anchoring strength much
lower than that used for existing minimally invasive annuloplasty
techniques. The initial anchoring strength is sufficient to
withstand the normal shear-forces, flow and contraction of the
beating heart but, may be less than that necessary for tightening
the annulus 2. The tightening procedure is subsequently performed
during a second procedure after allowing a sufficiently long period
of time for tissue remodeling 28 into and around the engaging
apparatus. It is expected that one week should be sufficient, but
it may be possible to use a shorter waiting time in some
circumstances.
[0037] Alternatively, in embodiments that rely on adhesion the
second step of tightening the engaging apparatus 56 may be
performed during the same procedure after allowing sufficient time
for adhesion to occur between the engaging apparatus 56 and the
annular tissue 2. The tightening procedure may also be performed in
any number of subsequent procedures or non-invasively through the
chest wall. Optionally, the engaging apparatus 56 may deliver
energy or focus externally transmitted energy to the annular
surface 2 in order to accelerate tissue growth into or around the
engaging apparatus 28.
[0038] FIG. 10 shows yet another embodiment in which the engaging
apparatus 66 contains an integral anchoring delivery system 30
which allows for an artificial valve 32 to be connected to the
engaging apparatus 66, during a subsequent procedure, instead of or
in addition to tightening of the annulus. The illustrated delivery
system may be used for replacement of a cardiac valve, such as the
mitral valve using a three step procedure: widening of the annulus,
placing the engaging apparatus 66, and anchoring an artificial
valve 32 to the engaging apparatus 66. Introduction of the
artificial valve 32 to the engaging apparatus may be performed
through an intra-vascular or minimally invasive approach.
[0039] FIG. 11 shows the FIG. 10 embodiment where the artificial
valve 32 is anchored to the engaging apparatus 66 during a
subsequent, minimally invasive procedure. Optionally, the engaging
apparatus 66 may be placed at the annulus 2 as a second step
procedure following widening of the annulus 2 and valve 8 using a
minimally invasive balloon inflation technique or any other method
for widening a stenotic valve. Subsequently, the artificial valve
32 may be attached to the engaging apparatus 66 during a third
procedure, instead of or in addition to tightening of the annulus
2.
[0040] All of the above-described embodiments advantageously permit
blood flow during insertion of the delivery system and the engaging
apparatus.
* * * * *