U.S. patent number RE46,127 [Application Number 14/699,447] was granted by the patent office on 2016-08-30 for annuloplasty with enhanced anchoring to the annulus based on tissue healing.
This patent grant is currently assigned to Cardiac Implants LLC. The grantee listed for this patent is Cardiac Implants LLC. Invention is credited to E. David Kirson.
United States Patent |
RE46,127 |
Kirson |
August 30, 2016 |
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) |
Applicant: |
Name |
City |
State |
Country |
Type |
Cardiac Implants LLC |
Tarrytown |
NY |
US |
|
|
Assignee: |
Cardiac Implants LLC
(Tarrytown, NY)
|
Family
ID: |
39226072 |
Appl.
No.: |
14/699,447 |
Filed: |
April 29, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
60822113 |
Aug 11, 2006 |
|
|
|
Reissue of: |
11837077 |
Aug 10, 2007 |
8430926 |
Apr 30, 2013 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61F
2/2409 (20130101); A61F 2/2418 (20130101); A61F
2/2466 (20130101); A61F 2/2412 (20130101); A61F
2/2445 (20130101); A61F 2/2409 (20130101); A61F
2/2442 (20130101); A61F 2/2466 (20130101); A61F
2/2418 (20130101); A61F 2250/0004 (20130101); A61F
2220/0016 (20130101); A61F 2220/0008 (20130101); A61F
2230/008 (20130101); A61F 2250/0059 (20130101); A61F
2250/006 (20130101) |
Current International
Class: |
A61F
2/24 (20060101) |
Field of
Search: |
;623/2.36-2.4,904
;606/151 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Maniu, MD, et al. Acute & Chronic Reduction of Functional
Mitral Regurgitation . . . Journal of the American College of
Cardiology, vol. 44, No. 8, pp. 1652-1661 (2004). cited by
applicant .
Cohn, et al., The Evolution of Mitral Valve Surgery, Am heart Hosp.
J. 2003:1 pp. 40-46 (2003). cited by applicant .
Damon, et al., Percutaneous Mitral Velve Repair for Chronic
Ischemic Mitral Regurgitation . . . Journal of the American Heart
Association, publ. Apr. 25, 2005. cited by applicant .
Felger, M.D., et al., Robot-Assisted Sutureless Minimally Invasive
Mitral Valve Repair, Cardiovascular Surgery, Surgical Technology
International XII, p. 185-187 (undated). cited by applicant .
Folliguet, et al., Mitral valve repair robotic versus sternotomy,
European Journal of Cardio-Thoracic Surgery 29 (2006) pp. 362-366.
cited by applicant .
Greelish et al., Minimally invasive mitral valve repair suggests
earlier operations for mitral valve . . . , The Journal of Thoracic
& Cardiovascular Surgery vol. 126, No. 2 (2003). cited by
applicant .
Desimone, et al., Adjustable Tricuspid Valve Annuloplasty Assisted
by Intraoperative Transesophageal . . . The American Journal of
Cardiology vol. 71 pp. 926-931 Apr. 15, 1993. cited by
applicant.
|
Primary Examiner: Williams; Catherine S
Attorney, Agent or Firm: Potomac Law Group, PLLC
Claims
I claim:
1. A method of tightening an annulus of a heart comprising the
steps of: pressing an engaging apparatus with a contractible
diameter up against an inner surface of the annulus, wherein the
engaging apparatus is configured to attach to the inner surface
with an initial anchoring strength when pressed against the inner
surface, wherein the initial anchoring strength is less than that
necessary to withstand tightening; waiting for a bond to develop
between the engaging apparatus and the annulus based on tissue
healing and remodeling into and around the engaging apparatus that
is strong enough to withstand tightening; and contracting the
engaging apparatus after development of the bond based on tissue
healing and remodeling.
2. The method of claim 1, wherein the pressing step comprises the
step of inflating a balloon-like object to press the engaging
apparatus against the inner surface of the annulus, and wherein the
balloon-like object has a channel that permits blood to flow
therethrough during the pressing step.
3. The method of claim 1, wherein the pressing step comprises the
step of opening a truncated wire-whisk shaped structure configured
to press the engaging apparatus against the inner surface of the
annulus, and wherein blood is free to flow past the truncated
wire-whisk shaped structure during the pressing step.
4. The method of claim 1, wherein the step of waiting for a bond to
develop between the engaging apparatus and the annulus comprises
waiting for at least one week.
5. The method of claim 1, wherein the engaging apparatus has an
annulus contact portion that is shaped like a helical spring that
has been formed to be substantially arc-shaped, with an arc that
subtends at least 270.degree..
6. 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
wherein the annulus contact portion is configured to attach to the
annulus with an initial anchoring strength when pressed against the
annulus, the initial anchoring strength being less than that
necessary to withstand tightening, and wherein the annulus contact
portion is also configured to permit tissue healing and remodeling
into and around the annulus contact portion that increases the
anchoring strength over time; a truncated wire-whisk shaped
structure configured to press the annulus contact portion against
the inner surface of the annulus while permitting blood to flow
freely past the truncated wire-whisk shaped structure; 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.
7. The apparatus of claim 6, wherein the annulus contact portion
has a plurality of barbs configured to promote initial anchoring of
the annulus contact portion to the annulus.
8. The apparatus of claim 6, wherein the substantially arc-shaped
annulus contact portion subtends an angle of at least
180.degree..
9. The apparatus of claim 6, wherein the substantially arc-shaped
annulus contact portion subtends an angle of at least
270.degree..
10. The apparatus of claim 6, wherein annulus contact portion
comprises a helical spring that has been formed into an arc.
11. The apparatus of claim 10, 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.
12. The apparatus of claim 10, wherein the annulus contact portion
has a plurality of barbs configured to promote attachment of the
annulus contact portion to the annulus.
13. The apparatus of claim 10, wherein the substantially arc-shaped
annulus contact portion subtends an angle of at least
180.degree..
14. The apparatus of claim 10, wherein the substantially arc-shaped
annulus contact portion subtends an angle of at least
270.degree..
15. The method of claim 3, wherein the step of waiting for a bond
to develop between the engaging apparatus and the annulus comprises
waiting at least one week.
16. The method of claim 3, wherein the engaging apparatus has an
annulus contact portion that is shaped like a helical spring that
has been formed to be substantially arc-shaped, with an arc that
subtends at least 270.degree..
.Iadd.17. A method of tightening an annulus of a heart comprising
the steps of: attaching an engaging apparatus with a contractible
diameter to the annulus, wherein the engaging apparatus is
configured to attach to the annulus with an initial anchoring
strength when attached to the annulus, wherein the initial
anchoring strength is less than that necessary to withstand
tightening; waiting for a bond to develop between the engaging
apparatus and the annulus based on tissue healing and remodeling
into and around the engaging apparatus that is strong enough to
withstand tightening; and contracting the engaging apparatus after
development of the bond based on tissue healing and
remodeling..Iaddend.
.Iadd.18. The method of claim 17, wherein the attaching step
comprises the step of inflating a balloon-like object to press the
engaging apparatus against the annulus, and wherein the
balloon-like object has a channel that permits blood to flow
therethrough during the attaching step..Iaddend.
.Iadd.19. The method of claim 17, wherein the attaching step
comprises the step of using a truncated wire-whisk shaped structure
to press the engaging apparatus against the annulus, and wherein
blood is free to flow past the truncated wire-whisk shaped
structure during the attaching step..Iaddend.
.Iadd.20. The method of claim 19, wherein the step of waiting for a
bond to develop between the engaging apparatus and the annulus
comprises waiting for at least one week..Iaddend.
.Iadd.21. The method of claim 17, wherein the step of waiting for a
bond to develop between the engaging apparatus and the annulus
comprises waiting at least one week..Iaddend.
.Iadd.22. An apparatus for repairing an annulus comprising: an
annulus contact portion having an outer boundary, wherein the
annulus contact portion has an inner core, and wherein the annulus
contact portion is configured to attach to the annulus with an
initial anchoring strength, the initial anchoring strength being
less than that necessary to withstand tightening, and wherein the
annulus contact portion is also configured to permit tissue healing
and remodeling into and around the annulus contact portion that
increases the anchoring strength over time; a truncated wire-whisk
shaped structure configured to press the annulus contact portion
against the annulus while permitting blood to flow freely past the
truncated wire-whisk shaped structure; 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..Iaddend.
.Iadd.23. The apparatus of claim 22, wherein the annulus contact
portion has a plurality of barbs configured to promote initial
anchoring of the annulus contact portion to the
annulus..Iaddend.
.Iadd.24. The method of claim 17, wherein the attaching step is
implemented using a catheter that is introduced
intravascularly..Iaddend.
.Iadd.25. The method of claim 19, wherein the attaching step is
implemented using a catheter that is introduced
intravascularly..Iaddend.
Description
.Iadd.NOTICE: More than one reissue application has been filed for
the reissue of U.S. Pat. No. 8,430,926. The reissue applications
are application Ser. No. 14/699,447 (the present application) and
application Ser. No. 14/699,621, both of which are reissues of U.S.
Pat. No. 8,430,926..Iaddend.
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. provisional application
No. 60/822,113, filed Aug. 11, 2006, which is incorporated herein
by reference.
BACKGROUND
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 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.
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.
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.
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.
Devices and methods that address these difficulties are described
in U.S. patent application Ser. Nos. 60/445,890, 60/459,735,
60/462,502, 60/524,622, 10/461,043, 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
FIG. 1 shows the location of the mitral annulus in a cross-section
of the heart.
FIG. 2 shows a first approach for positioning a first embodiment of
an engaging apparatus at the annulus.
FIG. 3 shows a cross section of the embodiment shown in FIG. 2.
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.
FIG. 5 shows a close up of the end of the FIG. 4 embodiment.
FIG. 6 is a detailed view of the first embodiment of the engaging
apparatus.
FIG. 7 shows a detailed view of another embodiment of the engaging
apparatus.
FIG. 8 shows the engaging apparatus of FIG. 7 in location at the
mitral annulus immediately after being positioned and anchored to
the tissue.
FIG. 9 shows the engaging apparatus of FIG. 7 after being left in
place for sufficient time for tissue healing and remodeling to
occur.
FIG. 10 shows another embodiment of an engaging apparatus that
contains an integral anchoring delivery system.
FIG. 11 shows the FIG. 10 embodiment with an artificial valve
anchored to the engaging apparatus.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
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.
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.
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.
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, books, 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.
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).
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.
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.
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 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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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 intravascular or minimally invasive approach.
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.
All of the above-described embodiments advantageously permit blood
flow during insertion of the delivery system and the engaging
apparatus.
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