U.S. patent application number 12/574563 was filed with the patent office on 2010-04-15 for multi-window guide tunnel.
This patent application is currently assigned to Guided Delivery Systems Inc.. Invention is credited to Huu Nguyen, Son Nguyen, Eugene Serina, Tammy Y. Tam.
Application Number | 20100094248 12/574563 |
Document ID | / |
Family ID | 40589715 |
Filed Date | 2010-04-15 |
United States Patent
Application |
20100094248 |
Kind Code |
A1 |
Nguyen; Huu ; et
al. |
April 15, 2010 |
MULTI-WINDOW GUIDE TUNNEL
Abstract
Described herein are devices and methods for delivering implants
that comprise multiple coupled anchors. The anchors are secured to
tissue using a multi-opening guide tunnel that is configured to
releasably retain one or more portions of the implant located
between two of the anchors. The releasable retention of one or more
intervening portions of the implant maintains the position of the
implant and the guide tunnel until the implant is secured to the
tissue. The multi-opening guide tunnel permits securement of the
multiple anchors without requiring repositioning of the guide
tunnel for each anchor.
Inventors: |
Nguyen; Huu; (San Jose,
CA) ; Nguyen; Son; (San Jose, CA) ; Serina;
Eugene; (Union City, CA) ; Tam; Tammy Y.; (San
Francisco, CA) |
Correspondence
Address: |
MORRISON & FOERSTER LLP
755 PAGE MILL RD
PALO ALTO
CA
94304-1018
US
|
Assignee: |
Guided Delivery Systems
Inc.
Santa Clara
CA
|
Family ID: |
40589715 |
Appl. No.: |
12/574563 |
Filed: |
October 6, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12366553 |
Feb 5, 2009 |
|
|
|
12574563 |
|
|
|
|
61026697 |
Feb 6, 2008 |
|
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|
Current U.S.
Class: |
604/500 |
Current CPC
Class: |
A61B 17/064 20130101;
A61B 2017/00783 20130101; A61F 2/2451 20130101; A61B 2017/0414
20130101; A61B 2017/0409 20130101; A61B 2017/00867 20130101; A61B
17/0684 20130101; A61B 2017/0464 20130101; A61B 17/10 20130101;
A61F 2/2445 20130101; A61B 17/0401 20130101; A61B 2017/00243
20130101; A61B 17/00234 20130101; A61B 17/0682 20130101; A61B
17/068 20130101 |
Class at
Publication: |
604/500 |
International
Class: |
A61M 31/00 20060101
A61M031/00 |
Claims
1. A method for performing a procedure inside a heart comprising:
positioning a guide adjacent to heart tissue, the guide having a
lumen at least partially therethrough; advancing a device at least
partially through the lumen; temporarily securing the guide to the
heart tissue using the device; releasing the guide from the heart
tissue, wherein at least a portion of the device remains secured to
the heart tissue; and removing the guide from the heart.
2. The method of claim 1 wherein the guide member comprises a
catheter.
3. The method of claim 1 wherein the guide member comprises a
plurality of openings.
4. The method of claim 3 wherein the plurality of openings are
located along a length of the guide member.
5. The method of claim 1 wherein the guide member comprises one or
more retention members.
6. The method of claim 1 wherein the device comprises at least one
anchor coupled to a tether.
7. The method of claim 1 wherein the guide is positioned adjacent
to the heart tissue using an intravascular approach.
8. The method of claim 1 wherein the guide is positioned adjacent
to the heart tissue using a surgical technique.
9. The method of claim 1 wherein the guide is positioned adjacent
to the heart tissue using port access to the heart.
10. The method of claim 1 wherein the heart tissue is ventricular
tissue.
11. The method of claim 1 wherein the heart tissue is within the
subannular groove region.
12. The method of claim 1 wherein the heart tissue is within the
subvalvular space.
13. The method of claim 1 wherein the guide is temporarily secured
to heart tissue using at least one anchor coupled to a tether.
14. The method of claim 1 wherein the guide comprises a plurality
of retention members and wherein the guide is released from the
heart tissue by moving the retention members.
15. The method of claim 3 wherein the device is deployed through
the plurality of openings.
16. The method of claim 1 wherein the guide comprises at least a
first opening and a second opening, both openings positioned along
a length of the guide.
17. The method of claim 16 wherein the device comprises at least a
first anchor and a second anchor, at least one of the first or
second anchors being fixedly coupled to a tether.
18. The method of claim 17 wherein the first anchor is deployed
through the first opening and the second anchor is deployed through
the second opening.
19. The method of claim 18 wherein at least one of the first or
second anchors is slidably coupled to the tether.
20. The method of claim 19 further comprising tensioning the
tether.
21. The method of claim 20 further comprising securing the tether
in its tensioned state.
22. The method of claim 21 further comprising cutting the tether.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation application of
U.S. application Ser. No. 12/366,553, filed Feb. 5, 2009, which
claims priority under 35 U.S.C. .sctn.119(e) to U.S. Provisional
Application No. 61/026,697, filed on Feb. 6, 2008, each of which
are hereby incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] Blood returning to the heart from the peripheral circulation
and the lungs generally flows into the atrial chambers of the heart
and then to the ventricular chambers, which pump the blood back out
of the heart. During ventricular contraction, the atrio-ventricular
valves between the atria and ventricles, i.e. the tricuspid and
mitral valves, close to prevent backflow or regurgitation of blood
from the ventricles back to the atria. The closure of these valves,
along with the aortic and pulmonary valves, maintains the
uni-directional flow of blood through the cardiovascular system.
Disease of the valvular apparatus can result in valve dysfunction,
where some fraction of the ventricular blood regurgitates back into
the atrial chambers.
[0003] Traditional treatment of heart valve stenosis or
regurgitation, such as mitral or tricuspid regurgitation, involves
an open-heart surgical procedure to replace or repair the valve.
Current accepted treatments of the mitral and tricuspid valves
include: valvuloplasty, in which the affected leaflets are
remodeled to perform normally; repair of the chordae tendineae
and/or papillary muscle attachments; and surgical insertion of an
"annuloplasty" ring, which requires suturing a flexible support
ring over the annulus to constrict the radial dimension. Other
surgical techniques to treat heart valve dysfunction involve
fastening (or stapling) the valve leaflets to each other or to
other regions of the valve annulus to improve valve function (see,
e.g., U.S. Pat. No. 6,575,971).
BRIEF SUMMARY OF THE INVENTION
[0004] Described herein are devices and methods that involve
attachment sites, including implants with multiple coupled anchors.
The anchors may be secured to tissue using a multi-opening guide
tunnel that is configured to releasably retain one or more portions
of the implant located between two anchors, such as a tether
component that attach the anchors. The releasable retention of one
or more interconnecting portions of the implant provides additional
stabilization for the delivery tool until the implant is secured to
the tissue. The multi-opening guide tunnel permits securement of
the multiple anchors without requiring repositioning of the guide
tunnel for each anchor. In some embodiments, the multi-opening
guide tunnel comprises disengageable wall segments between the
openings of the guide tunnel, which provide structural support and
column strength in a region of the guide tunnel that would buckle
or collapse due to the number of openings and their
configuration.
[0005] In some embodiments, a system for use in a patient is
provided, comprising an outer catheter, which comprises a
passageway with a proximal end, a distal end, a longitudinal axis
and two or more outer openings, and at least one releasable
retaining structure located between the two or more outer openings.
At least one releasable retaining structure may be adapted to open
a release channel between two or more outer openings. In some
instances, at least two of the two or more outer openings are two
adjacent outer openings with a separation distance less than a
maximum dimension of one of the two adjacent outer openings, and at
least one releasable retaining structure is located between the two
adjacent outer openings. In some variations, two or more outer
openings are longitudinally spaced along a longitudinal length of
the outer catheter, and may be configured for passage of a tissue
anchor. At least one releasable retaining structure may be
configured to retain a tether attached to the tissue anchor, and is
optionally an outer wall structure of the outer catheter. The outer
catheter may comprise at least three outer openings, and optionally
at least two releasable retaining structures. The system may
further comprise an inner catheter slidably located in the
passageway of the outer catheter, and sometimes may further
comprise an alignment interface between the outer catheter and the
inner catheter. The alignment interface may comprise a rail, which
may be a metallic material and/or may be secured to the outer
catheter at two or more securing sites. The outer catheter may also
further comprise a curved configuration having a lesser curvature
and a greater curvature, and in some embodiments, two or more
openings may be generally located along the greater curvature of
the outer catheter. The outer catheter may also comprise an
atraumatic tip. The catheter may further comprise at least one
radio-opaque structure located between the two or more outer
openings. The inner catheter may comprise an inner opening and
wherein the inner guide and outer guide are configured to permit
positioning of the inner opening at two or more outer openings. In
some embodiments, at least one releasable retaining structure
comprises a locking passage. The at least one locking element may
be configured for removable positioning in the locking passage of
at least one releasable retaining structure, and at least two
releasable retaining structures with locking passages are both
optionally configured for removable positioning by one of the at
least one locking elements.
[0006] In other embodiments, an implant delivery system is
provided, comprising a catheter body which comprises a proximal
end, a distal end, a longitudinal lumen therebetween, a lumenal
surface, an ablumenal surface, and at least one implant delivery
opening in communication with the longitudinal lumen and located
between the luminal surface and the ablumenal surface, and at least
two longitudinally-spaced retention members located distal to the
proximal end of the catheter body. In some instances, at least two
longitudinally-spaced retention members are located within the
longitudinal lumen, or within the at least one implant delivery
opening. At least two longitudinally-spaced retention members may
have a transverse orientation with respect to the longitudinal
lumen. In some embodiments, at least two longitudinally-spaced
retention members are movable retention members, which may be
rotatable or flexible retention members. The movable retention
members may each comprise a through lumen. The implant delivery
system may further comprise a first anchor coupled to a tether, and
in some instances at least two longitudinally-spaced retention
members are configured to retain the tether.
[0007] In another embodiment, a method for securing anchors to a
body structure is provided, comprising providing an implant
comprising a first anchor, a second anchor, and a first coupling
portion therebetween, passing the first anchor and the second
anchor into a common lumen of a catheter, deploying the first
anchor through a first opening of the catheter, deploying the
second anchor through a second opening of the catheter, retaining
the first coupling portion of the implant in the catheter, wherein
the first coupling portion is located between two anchors secured
to the body structure, and releasing the first coupling portion of
the implant from the catheter after securing the first anchor and
the second anchor to body tissue. The method may further comprise
positioning the catheter in a subvalvular space of a ventricle. In
some instances, releasing the first coupling portion of the implant
from the catheter may comprise disengaging a wall section of the
catheter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The structure and method of using the invention will be
better understood with the following detailed description of
embodiments of the invention, along with the accompanying
illustrations, in which:
[0009] FIG. 1 is a cross-sectional view of a heart with a guide
catheter device advanced through the aorta into the left
ventricle;
[0010] FIG. 2 is a flowchart representation of a method for
delivering at least two anchors into a subvalvular region;
[0011] FIGS. 3A to 3I schematically depict a method for delivering
multiple tissue anchors using a guide tunnel having multiple tissue
openings;
[0012] FIGS. 4A and 4B illustrate the use of various tissue anchors
with a guide tunnel having multiple tissue openings; FIG. 4C shows
the use of the guide tunnel in the coronary sinus;
[0013] FIGS. 5A to 5D are cross-sectional views of a portion of a
heart, schematically illustrating the positioning and deployment of
a flexible device for treatment of a mitral valve annulus;
[0014] FIGS. 6A to 6C are schematic cross-sectional views of one
embodiment of the invention comprising a self-forming anchor
attaching to tissue;
[0015] FIG. 7A depicts one embodiment of a multi-opening guide
tunnel; FIG. 7B depicts the multi-opening guide tunnel of FIG. 7A
with its latches unlocked and separated from the body of the guide
tunnel; FIG. 7C illustrates one embodiment of an inner guide tunnel
usable with the multi-opening guide tunnel of FIG. 7A; FIGS. 7D and
7E are schematic cross-sectional views of the multi-opening guide
tunnel at various locations;
[0016] FIGS. 8A to 8D represent various embodiments of a latch;
FIGS. 8E and 8F are schematic representations of various locking
lumens for a latch;
[0017] FIGS. 9A and 9B are schematic illustrations of various
locking wire embodiments;
[0018] FIGS. 10A and 10B schematically depict various latch and
opening configurations for a guide tunnel;
[0019] FIG. 11 is a perspective view of a distal portion of one
embodiment of an anchor delivery catheter;
[0020] FIGS. 12A and 12B are perspective views of a distal portion
of another embodiment of an anchor delivery catheter;
[0021] FIG. 13A is a perspective view of another embodiment of a
delivery catheter, FIG. 13B is a frontal view of the delivery
catheter of FIG. 13A, and FIGS. 13C and 13D are side and bottom
views, respectively, of a portion of the delivery catheter of FIG.
13A;
[0022] FIGS. 14A to 14H are various perspective views of one
embodiment of a multi-opening guide tunnel;
[0023] FIGS. 15A to 15F schematically demonstrate a method for
applying anchors from the subvalvular space;
[0024] FIGS. 16A and 16B are schematic top-views of a plurality of
anchors coupled to a self-deforming coupling member, with the
coupling member shown in an undeployed shape and a deployed shape,
respectively;
[0025] FIG. 17 shows a transseptal approach to the left
ventricle;
[0026] FIG. 18 shows a transapical approach to the left
ventricle;
[0027] FIG. 19 is a schematic view of the heart illustrating
various dimensions of a heart chamber;
[0028] FIG. 20 is schematic view of the heart illustrating various
dimensions of a heart chamber;
[0029] FIG. 21 depicts the use of a multi-opening guide tunnel
along a longitudinal portion of the left ventricle;
[0030] FIGS. 22A and 22B represent another embodiment of a guide
tunnel;
[0031] FIGS. 23A and 23B represent still another embodiment of a
guide tunnel;
[0032] FIG. 24 is a schematic side view of another embodiment of a
guide tunnel with openings comprising non-orthogonal edges;
[0033] FIG. 25A is a perspective views of one embodiment of a
hemostatic seal; FIG. 25B is an posterior elevational view of the
seal of FIG. 25A; FIG. 25C is a cross-sectional view of the seal in
FIG. 25B; and
[0034] FIG. 26 is a posterior elevational view of an alternate seal
configuration.
DETAILED DESCRIPTION OF THE INVENTION
[0035] Although a number of surgically implanted ventricular
devices and procedures, such as the implantation of an annuloplasty
ring or edge-to-edge leaflet repair, are available for treating
valvular dysfunction, each procedure presents its own set of risks
to the patient or technical challenges to the physician. For
example, the ability to accurately and reliably position a cardiac
implant during a beating heart procedure, whether by open chest or
minimally invasive access, remains elusive to the average
practitioner. In particular, the percutaneous or transvascular
implantation of a ventricular device described herein poses a
significant challenge due to the instability from the wall motion
of a beating heart.
[0036] Devices, systems and methods of the instant invention are
generally used to reshape atrio-ventricular valves or myocardium to
improve hemodynamic performance. The implantation procedures are
preferably transvascular, minimally invasive or other "less
invasive" surgical procedures, but can also be performed with open
or limited access surgical procedures. When used for treatment of a
cardiac valve dysfunction, the methods generally involve
positioning one or more anchor delivery devices at a target site
using a guide tunnel, delivering a plurality of slidably coupled
anchors from the delivery device(s), and drawing the anchors
together to tighten the annulus. The devices include an elongate
catheter with a housing at or near the distal end for releasably
housing one or more anchors, as well as guide devices for
facilitating advancement and/or positioning of an anchor delivery
device. The devices may be positioned such that the housing abuts
or is close to valve annular tissue, such as the region within the
upper left ventricle bound by the left ventricular wall, a mitral
valve leaflet and chordae tendineae. Self-securing anchors having
any of a number of different configurations may be used in some
embodiments.
[0037] In FIG. 1, a cross-sectional depiction of a heart H is shown
with one embodiment of a guide catheter 100 advanced in a
retrograde direction through the aorta A and into the left
ventricle LV. Retrograde, as used herein, generally refers to a
direction opposite the expected flow of blood. This access route is
used to reach the subvalvular space 106. Guide catheter 100 is
generally a flexible elongate catheter which may have one or more
curves or bends toward its distal end to facilitate placement of
the distal end 102 of the catheter 100 at the desired location. The
subvalvular space, as used herein, generally includes the portion
of the ventricular chamber that is bound peripherally by the
ventricular wall, superiorly by the atrio-ventricular valve
leaflets, and centrally by the primary chordae tendineae, and is
located along the circumference of the valve annulus. The
subannular groove region, as used herein, includes the space
bordered by the inner surface of the ventricular wall, the inferior
surface of valve leaflets L, and the third order chordae tendineae
CT connected directly to the ventricular wall VW and the leaflet L.
The distal end 102 of guide catheter 100 may be configured to be
positioned at an opening into the subvalvular space 106 or within
the subvalvular space 106, such that subsequent delivery devices
may be passed through guide catheter 100 into the subvalvular space
106. Although the retrograde aortic access route preferably starts
from a percutaneous or peripheral access site, in some embodiments,
aortic access may be achieved by an incision in the ascending
aorta, descending aorta, aortic arch or iliac arteries, following
surgical, thorascopic or laparoscopic access to a body cavity.
[0038] In other embodiments of the invention, other spaces bound by
or relating to one or more cardiac structures may be used as a
target region of the heart. These structures include but are not
limited to the base of the ventricle, the mitral valve, the
tricuspid valve, the primary chordae tendineae, the secondary
chordae tendineae, the tertiary chordae tendineae, the anterior
mitral valve leaflet chordae tendineae, the posterior mitral valve
leaflet chordae tendineae, the interleaflet chordae tendineae, the
papillary muscle, the anterior-lateral papillary muscle, the
posterior-medial papillary muscle, the ventricular apical region,
and the ventricular apex. For example, in some embodiments, a
supra-apical space from about the base of the mitral valve leaflets
to the just above the ventricular apex or apical region may be the
target region. In another example, the target region may be the
peri-papillary muscle region, which includes the space about 1 cm
above and about 1 cm below the level of the papillary muscle
region, as well as the spaces between the papillary muscles. In
some examples, the target region may be the endocardial surface
abutting or accessible from the given space or cardiac structures.
In still other embodiments, the target region may be a region
between the base and apex of a ventricle and between longitudinal
borders drawn through the papillary muscles, e.g. either a
posterior-lateral or an anterior-medial ventricular endocardial
surface. In other embodiments, the target region may exclude the
space along the longitudinal axis from the base of a ventricle to
the apex of the ventricle, e.g. the target region may be tubular or
toroidal in configuration, with an internal border relating to a
chordae tendineae. Other examples of target regions are depicted in
FIGS. 19 and 20, and are discussed in greater detail below.
[0039] FIG. 2 provides a flowchart depiction of one method 120 for
deploying at least two anchors of the implant in the region of a
heart valve annulus. As shown there, this illustrative method
comprises advancing a guide catheter to the subannular groove
region 122, advancing a guidewire through a lumen of the guide
catheter 124, advancing a guide tunnel or tunnel catheter over the
guidewire 126, and proximally withdrawing the guidewire from the
tunnel catheter 128. In this particular embodiment, the tunnel
catheter comprises an outer catheter with a passageway in which an
inner catheter slidably resides. After the guidewire has been
proximally withdrawn, a first delivery catheter may be advanced
through the lumen of the tunnel catheter 130 and a first anchor may
be deployed into a first region of the heart valve annular tissue
132. The first anchor is typically coupled or secured to a guide
element, such as a tether. In this way, after the first anchor is
secured to heart tissue, the guide element will remain coupled to
the first anchor. While the guide element may be used as a track or
monorail for the advancement of additional delivery catheters
thereover, the guide element is also a component of the implant
that interconnects the multiple anchors. A portion of the guide
element facilitates the tightening of the implant and remains in
the body with the anchors after the delivery system is removed from
the body.
[0040] The guide element may be made from any suitable or desirable
biocompatible material. The guide element may be braided or not
braided, woven or not woven, reinforced or impregnated with
additional materials, or may be made of a single material or a
combination of materials. For example, the guide element may be
made from (1) a suture material (e.g., absorbable suture materials
such as polyglycolic acid and polydioxanone, natural fibers such as
silk, and artificial fibers such as polypropylene, polyester,
polyester impregnated with polytetrafluoroethylene, nylon,
polyetheretherketone, etc.), (2) a metal (absorbable or
non-absorbable), (3) a metal alloy (e.g., stainless steel), (4) a
shape memory material, such as a shape memory alloy (e.g., a nickel
titanium alloy), (5) other biocompatible material, or (6) any
combination thereof. In some variations, when pulled proximally
while restraining the position of the proximal anchor, the guide
element may be used to cinch or reduce the circumference of the
atrio-ventricular valve annulus or the annular tissue. In certain
variations, the guide element may be in the form of a wire. The
guide element may include multiple layers, and/or may include one
or more coatings. For example, the guide element may be in the form
of a polymer-coated wire. In certain variations, the guide element
may consist of a combination of one or more sutures and one or more
wires. As an example, the guide element may be formed of a suture
that is braided with a wire. In some variations, the guide element
may be formed of one or more electrode materials. In certain
variations, the guide element may be formed of one or more
materials that provide for the telemetry of information (e.g.,
regarding the condition of the target site).
[0041] In some embodiments, the guide element may include one or
more therapeutic agents (e.g., drugs, such as time-release drugs).
As an example, the guide element may be partially or entirely
coated with one or more therapeutic agents. In certain variations,
the guide element may be used to deliver one or more growth factors
and/or genetic regenerative factors. In some variations, the guide
element may be coated with a material (e.g., a polymer) that
encapsulates or controls the release rate one or more therapeutic
agents, or in which one or more therapeutic agents are embedded.
The therapeutic agents may be used, for example, to treat the
target site to which the guide element is fixedly attached or
otherwise secured. In certain variations, the guide element may
include one or more lumens through which a therapeutic agent can be
delivered.
[0042] After the first anchor has been deployed in the region of
the heart valve annular tissue, the first delivery catheter is
withdrawn proximally from the tunnel catheter. While maintaining
the existing position of the outer catheter of the tunnel catheter
about the subannular groove region, the inner catheter of the
tunnel catheter is repositioned at a second opening of the outer
catheter 134. A second delivery catheter is then advanced over the
guide element through the lumen of the tunnel catheter 136. In some
embodiments, subsequent delivery of anchors can be achieved by
removing and reloading the first delivery catheter. In other
embodiments, the delivery catheter is loaded with a plurality of
anchors and does not need to be withdrawn from the tunnel catheter
to deliver subsequent anchors.
[0043] During advancement of the second delivery catheter over the
guide element, the guide element may enter the second delivery
catheter through an opening at its distal end, and exit the second
delivery catheter through an opening in its side wall that is
proximal to its distal end. Alternatively, the guide element may
enter the second delivery catheter through an opening at its distal
end, and exit the second delivery catheter through an opening at
its proximal end, or at any other location proximal to the distal
end. After the second delivery catheter has been advanced over the
guide element through the lumen of the tunnel catheter, a second
anchor is deployed into a second region of the heart valve annular
tissue using a second opening of the tunnel catheter 138.
[0044] The procedure described above represents one embodiment of
the invention that may be used to treat the annular tissue of the
mitral valve. In other embodiments of the invention, other tissues
or structures of the heart and vasculature can also be treated,
including but not limited to the subvalvular apparatus, septal
structures and the myocardium. In still other embodiments, one or
more cinchable implants may be deployed in non-cardiac tissues or
structures, for example, to treat gastrointestinal disorders such
as obesity, genitourinary conditions such as incontinence, or to
perform cosmetic and reconstructive procedures.
[0045] FIGS. 3A to 3I provide a more detailed depiction of the
method shown in flowchart form in FIG. 2. In FIGS. 3A to 3I, the
mitral valve MV of FIG. 1 is depicted schematically from an
inferior perspective looking in a superior direction, but in other
embodiments of the invention the tricuspid valve, pulmonary valve
or aortic valve may be accessed. Referring to FIG. 3A, a guide
catheter 140 is advanced to subannular groove region 104 using any
of the access routes (or any other suitable access routes)
described herein. In FIG. 3B, after guide catheter 140 has been
positioned at the desired location in subannular groove region 104,
a guidewire 144 is advanced through the lumen of guide catheter
140. Guidewire 144 may be advanced beyond the distal end 146 of
guide catheter 140, so that guidewire 144 extends further along
subannular groove region 104 than guide catheter 140, as shown in
FIG. 3B.
[0046] After guidewire 144 has been positioned in the subannular
groove region 104, a guide tunnel or tunnel catheter 148 is
advanced through guide catheter 140, over guidewire 144, as shown
in FIG. 3C. Tunnel catheter 148 may be any suitable catheter, and
in some instances, it is desirable that the tunnel catheter be
pre-shaped or pre-formed at its distal end, such as the tunnel
catheter illustrated in FIG. 3C. In some embodiments, tunnel
catheter 148 may have a pre-shaped distal portion that is curved.
In this way, the tunnel catheter may more easily conform to the
geometry of the atrio-ventricular valve. It should also be
understood that any of the catheters or guidewires described here
may be pre-shaped or pre-formed to include any number of suitable
curves, angles or configurations. Of course, the guidewires and/or
catheters described here may also be steerable.
[0047] After tunnel catheter 148 has been positioned in the
subannular groove region 104, guidewire 144 is withdrawn proximally
as shown in FIG. 3D. A delivery catheter (not shown) may then be
advanced through the lumen of tunnel catheter 148 and toward
opening 154 at or adjacent to the distal tip 156 of tunnel catheter
148. In the embodiment depicted in FIG. 3E, the delivery catheter
remains within tunnel catheter 148, and anchor 158 is deployed
through opening 154 to attach to the body tissue. In other
embodiments, however, the delivery catheter may be extended through
opening 154 of tunnel catheter 148. Exemplary embodiments of a
delivery catheter are depicted and described in greater detail
below.
[0048] In some embodiments of the invention, opening 154 is the
distalmost anchor delivery opening of tunnel catheter 148, but in
some embodiments, one or more openings may have a separate lumen in
tunnel catheter 148, so that any anchors deployed from such
openings would not interfere or restrict the deployment of
subsequent tissue anchors distal to those openings. Furthermore,
although FIG. 3E depicts opening 154 as a side opening of tunnel
catheter 148, in some embodiments, opening 154 may be located at
the distal tip 156 and may be the same opening shown with a
distally protruding guidewire 144 in FIG. 3C.
[0049] Anchor 158, shown in FIG. 3E, is preferably a self-expanding
design as it exits the delivery catheter and tunnel catheter 148 to
self-secure into the annular tissue accessible from the subannular
groove region 104. It should be understood that one or more anchors
of an implant may be deployed into the annulus directly, while
other anchors may be secured to other tissue in the vicinity of the
subannular groove region 104. For example, one or more anchors may
be secured to the tissue below the annulus. After anchor 158 has
been deployed, the delivery catheter may be proximally withdrawn. A
tether 160, attached to anchor 158 and seen best in FIGS. 3G and
3H, may be used to facilitate the insertion of additional delivery
catheters toward the implantation site.
[0050] In this particular embodiment, as demonstrated in FIG. 3F,
tunnel catheter 148 is maintained in the same position while
additional anchors 164 and 158' are deployed from additional
openings 164' and 154' along tunnel catheter 148. In some
embodiments, one or more delivery catheters are serially inserted
into tunnel catheter 148 using tether 160 to serially guide anchors
164 and 158' through openings 164' and 154'. In some embodiments,
the delivery catheters may be loaded with one or more anchors at
the point-of-use, while in other embodiments the delivery catheters
may be pre-loaded at the point-of-manufacture. In other
embodiments, the delivery catheters may be reloaded at the
point-of-use, while in other embodiments, the delivery catheters
are single-use devices that are discarded after anchor deployment.
In other embodiments, the delivery catheters are configured to hold
two or more anchors 158, 158' and 164 and can deliver multiple
anchors without requiring withdrawal of the delivery catheter
between anchor deployments. Still other multi-anchor delivery
catheters are configured to deliver multiple anchors simultaneously
through multiple openings of tunnel catheter 148. Anchors 158, 158'
and 164 may be deployed from the delivery catheter and tunnel
catheter 148 in any suitable fashion, including but not limited to
a push-pull wire, using a plunger, or other suitable actuation
technique. Similarly, anchors 158, 158' and 164 may be coupled to
tether 160 by any suitable attachment method. For example, one or
more knots, welded regions, and/or adhesives may be used. Alternate
embodiments for anchor deployment and anchor attachments are
described in U.S. patent application Ser. No. 11/583,627, which is
hereby incorporated by reference in its entirety.
[0051] "Anchors," for the purposes of this application, are defined
to mean any fasteners. Thus, the anchors may comprise C-shaped or
semicircular hooks, curved hooks of other shapes, straight hooks,
barbed hooks, clips of any kind, T-tags, or any other suitable
fastener(s). In one embodiment, anchors may comprise two tips that
curve in opposite directions upon deployment, forming two
intersecting semi-circles, circles, ovals, helices or the like. In
some embodiments, the tips may be sharpened or beveled. In some
embodiments, the anchors are self-deforming. By "self-deforming" it
is meant that the anchors are biased to change from a first
undeployed shape to a second deployed shape upon release of the
anchors 210 from a restraint. Such self-deforming anchors may
change shape as they are released from a housing or deployed from a
lumen or opening to enter annular tissue, and secure themselves to
the tissue. Self-deforming anchors may be made of any suitable
material such as spring stainless steel, or super-elastic or
shape-memory material like nickel-titanium alloy (e.g.,
Nitinol).
[0052] In other embodiments, the anchors may be made of a elastic
material and may be loaded into a delivery catheter in such a way
that they change shape upon release. For example, anchors that are
not self-deforming may be secured to tissue via crimping, firing or
other application of mechanical force to facilitate tissue
penetration and/or securement. Even self-securing anchors may be
crimped in some embodiments of the invention, to provide enhanced
attachment to tissue. In some embodiments, anchors may comprise one
or more bioactive agents, including biodegradable metals and,
polymers. In another embodiment, the anchors may comprise electrode
components. Such electrodes, for example, may sense various
parameters including but not limited to impedance, temperature and
electrical signals. In other embodiments, such electrodes may be
used to supply energy to tissue at ablation or sub-ablation
amounts.
[0053] FIG. 4A, for example, depicts an implant comprising multiple
self-expanding, non-plicating anchors 166 deployed in the
subannular groove region 104. FIG. 4B depicts an implant comprising
multiple T-tag anchors 168 deployed in the subannular groove region
104, and FIG. 4C depicts transmural anchors 170 inserted from the
coronary sinus 172 and into the subannular groove region 104. Other
anchors may comprise fibrous or porous materials in the shape of
bars, rods or pledgets. In some instances, the fibrous or porous
materials may expand in volume. Additionally, while the delivery
and deployment of multiple anchors of the same shape over a single
guide element have been described, in some variations, a single
guide element can be used to deliver and deploy multiple anchors
having different shapes or non-uniform implantation sites.
Similarly, in certain embodiments, a single guide element can be
used in the delivery and deployment of multiple anchors having
different sizes. Illustrative examples of suitable anchors are
described in more detail, for example, in U.S. patent application
Ser. No. 11/202,474, which is hereby incorporated by reference in
its entirety.
[0054] In the embodiments depicted in FIGS. 3A to 3I, before a
second delivery catheter is advanced through tunnel catheter 148,
tether 160 is threaded into the delivery catheter, and is slidably
engaged with a second anchor 164. In some embodiments, second
anchor 164 is preloaded into the second delivery catheter before
threading to tether 160, while in other embodiments, the second
anchor is pre-threaded before being loaded into the second delivery
catheter. Any of a number of different methods can be used to
thread a guide element, such as tether 160, into a delivery
catheter, and to engage the guide element with an anchor. Other
methods are disclosed in U.S. patent application Ser. No.
11/202,474, which was previously incorporated by reference, and
threading devices are described, for example, in U.S. patent
application Ser. No. 11/232,190, which is hereby incorporated by
reference in its entirety.
[0055] With reference to FIG. 3G, after all of anchors 158, 158'
and 164 have been deployed into body tissue, tunnel catheter 148 is
withdrawn from guide catheter 140. The separation of the tunnel
catheter 148 from the anchors 158, 158' and 164 may occur by any of
a variety of mechanisms, examples of which are described in greater
detail below. In FIG. 3H, a termination catheter 174 is inserted
through guide catheter 140 over tether 160. Termination catheter
174 is used to facilitate tensioning of tether 160, thereby
cinching anchors 158, 158' and 164 together to remodel the annular
tissue and to secure the cinched anchors 158, 158' and 164 with a
termination member 176 that resists tether loosening or slippage,
as illustrated in FIG. 3I. In other embodiments, termination
catheter 174 can secure tether 160 to an anchor or to body tissue
without the use of termination member 176. Devices and methods for
performing termination of cinchable implants are described in U.S.
patent application Ser. No. 11/232,190, which was previously
incorporated by reference.
[0056] The catheters described herein, including tunnel catheter
148, may be formed of any of a number of different materials.
Examples of suitable materials include polymers, such as
polyether-block co-polyamide polymers, copolyester elastomers,
thermoset polymers, polyolefins (e.g., polypropylene or
polyethylene, including high-density polyethylene and low-density
polyethylene), polytetrafluoroethylene, ethylene vinyl acetate,
polyamides, polyimides, polyurethanes, polyvinyl chloride (PVC,
fluoropolymers (e.g., fluorinated ethylene propylene,
perfluoroalkoxy (PFA) polymer, polyvinylidenefluoride, etc.),
polyetheretherketones (PEEKs), and silicones. Examples of
polyamides include Nylon 6 (e.g., Zytel.RTM. HTN high performance
polyamides from DuPont.TM.), Nylon 11 (e.g., Rilsan.RTM. B
polyamides from Arkema Inc.), and Nylon 12 (e.g., Grilamid.RTM.
polyamides from EMS-Grivory, Rilsan.RTM. A polyamides from Arkema
Inc., and Vestamid.RTM. polyamides from Degussa Corp.). In some
variations, tunnel catheter 148 may be formed of multiple polymers.
For example, a catheter may be formed of a blend of different
polymers, such as a blend of high-density polyethylene and
low-density polyethylene. While the wall of a catheter may be
formed of a single layer, some variations of catheters may include
walls having multiple layers (e.g., two layers, three layers).
Furthermore, some variations of catheters may include at least two
sections that are formed of different materials and/or that include
different numbers of layers. Additionally, certain variations of
catheters may include multiple (e.g., two, three) lumens. The
lumens or walls may, for example, be lined and/or reinforced (e.g.,
with braiding or winding). The reinforcing structures, if any, may
be metallic or comprise a non-metal or polymer having a higher
durometer.
[0057] As illustrated in FIG. 5A, in one embodiment of the
invention, distal portion 102 of delivery device 100 is positioned
in a desired location under a valve leaflet L and adjacent a
ventricular wall VW. The valve annulus VA generally comprises an
area of heart wall tissue at the junction of the ventricular wall
VW and the atrial wall AW that is relatively fibrous and, thus,
significantly stronger than leaflet tissue and other heart wall
tissue. It is noted, however, that considerable structural
variations of the annulus exist within patient populations and that
attempted delivery of an implant to the valve annulus VA may
instead contact or attach to the tissue adjacent to the valve
annulus. The term "annular tissue" as used herein shall include the
valve annulus and the tissue adjacent or surrounding the valve
annulus.
[0058] Distal portion 102 of guide catheter 100 may be advanced
into position generally under the valve annulus VA by any suitable
technique, some of which are described below. Distal portion 102 of
guide catheter 100 may be used to deliver anchors to the valve
annular tissue, to stabilize and/or expose the annulus, or both. In
one embodiment of the invention, using guide catheter 100 having a
flexible elongate body as shown in FIG. 1, flexible distal portion
102 may be positioned in the left ventricle LV at the level of the
mitral valve leaflets MVL using any of a variety of access routes
described herein. Distal portion 102 may be advanced under the
posterior valve leaflet into a space such as the subannular groove
region 104 or in the subvalvular space 106. Referring back to FIG.
5A, It has been found that when guide catheter 100 is passed, for
example, under the mitral valve via an intravascular approach,
guide catheter 100 may be inserted into the subannular groove
region 104 or the subvalvular space 106 and advanced either
partially or completely around the circumference of the valve. Once
in subannular groove region 104 or the subvalvular space 106,
distal portion 102 of guide catheter 100 may be positioned
proximate to the intersection of the valve leaflet(s) and the
ventricular wall VW, which is near the valve annulus VA. These are
but examples of possible access routes of an anchor delivery device
to a valve annulus, and any other access routes may be used. In
other embodiments, guide catheters such as those described in U.S.
Pat. No. 6,203,531, may be used. U.S. Pat. No. 6,203,531 is herein
incorporated by reference in its entirety.
[0059] In some embodiments, it may be advantageous to provide guide
catheter 100 with a curvable portion with a radius in an
expanded/curved state that is greater than a radius of the valve
annulus, the subannular groove region or ventricular chamber. The
relative size of this portion of guide catheter 100, when
positioned within the smaller sized ventricle, may exert a radially
outward force that can improve the surface contact between guide
catheter 100 and the left ventricle LV. For example, in one
embodiment, guide catheter 100 in the expanded state has a radius
about 25% to about 50% larger that the valve annulus.
[0060] In addition to delivering anchors to the annular tissue, the
guide catheter 100 (and specifically distal portion 102) may be
used to stabilize and/or expose the valve annulus or annular
tissue. Such stabilization and exposure are described fully in U.S.
patent application Ser. No. 10/656,797, which is incorporated by
reference in its entirety. For example, once the distal portion 102
is positioned generally under the annular tissue, force may be
applied to the distal portion 102 to stabilize the valve annulus VA
or annular tissue, as shown in FIG. 5B. Such force may be directed
in any suitable direction to expose, position and/or stabilize the
annulus or annular tissue. In another example, an upward and
lateral force is shown in FIG. 5B by the solid-headed arrow drawn
from the center of the distal portion 102. In other examples, only
upward, only lateral, or any other suitable force(s) may be
applied. With application of force to the distal portion 102, the
annular tissue may rise or project outwardly, thus exposing the
annulus for easier viewing or access. The applied force may also
stabilize the valve annulus VA or valve annular tissue, also
facilitating surgical procedures and visualization.
[0061] In some embodiments, additional force may be exerted by the
delivery device after the first anchor is engaged to body tissue.
The first anchor may provide additional leverage and stability for
manipulating the delivery device(s). Referring to FIGS. 5C and 5D,
a delivery device 108 is schematically shown delivering an anchor
110 to a valve annulus VA or annular tissue. Embodiments of anchor
delivery device 108 are described in greater detail below. Anchor
110 is shown first housed within delivery device 108 in FIG. 5C and
then delivered to the annulus VA or annular tissue, as depicted in
FIG. 5D. Of course, although the delivery and position of the
anchor 110 is described with respect to the valve annulus VA, one
or more anchors 110 may miss the valve annulus VA and attach to
other structures or tissues accessible from the subannular groove
region 104 (or subvalvular space 106).
[0062] As is shown, in some embodiments, anchors 110 may have a
relatively straight configuration when housed in delivery device
108, with two penetrating tips and a loop in between the tips. Upon
deployment from delivery device 108, the tips of anchor 110 may
curve in opposite directions to form two semi-circles, circles,
ovals, overlapping helices or the like. This is but one example of
a type of self-securing anchor which may be delivered to an annular
tissue. Additional anchor embodiments are described below, and may
also be found in U.S. patent application Ser. No. 11/202,474, which
was previously incorporated by reference. Multiple coupled anchors
110 may be delivered, and the anchors 110 are drawn together to
tighten the valve annulus.
[0063] Although delivery device 108 is shown having a circular
cross-sectional shape in FIGS. 5C and 5D, it may alternatively have
any other suitable shape. In one embodiment, for example, it may be
advantageous to provide a delivery device having an ovoid or
elliptical cross-sectional shape. Such a shape may help ensure that
the device is aligned, when positioned between a corner formed by a
ventricular wall and a valve leaflet, such that one or more
openings in the delivery device is oriented to deliver the anchors
in their desired orientation into valve annulus tissue. To further
enhance contacting of the annular tissue and/or orientation of the
delivery device, some embodiments may further include an expandable
member, coupled with the delivery device, which expands to urge or
press or wedge the delivery device into the corner formed by the
ventricle wall and the leaflet to contact the valve annulus. Such
enhancements are described further below.
[0064] In several embodiments of the invention, one or more
self-forming anchors 900 are stored in the delivery device in a
straightened configuration, coupled with a tether 902, as shown in
FIG. 6A. Anchors 900 are held or restrained in that straightened
state, while their deployed configuration is non-linear or curved.
Arms 901 meet at a junction section 903, which is slidably coupled
to the tether 902. In some embodiments, junction section 903
comprises an open or closed loop configuration and may change in
size or configuration when arms 901 are deployed. In this
particular embodiment, as arms 901 of anchor 900 are released from
the delivery system, arms 901 are permitted to resume their
deployed configuration, penetrating the tissue T along a
penetration pathway. As the distal portions of arms 901 regain
their deployed configurations, arms 901 will separate and reorient
toward the tissue surface (as depicted as open-headed arrows). In
some embodiments, the penetration pathways are curved so that as
anchor 900 further penetrates into tissue T, junctional section 903
of anchor 900 will continue along a similar pathway as the arms
901. This may reduce the degree of tissue compression or stretching
as anchor 900 is deployed, which in turn may also reduce any
resulting arrythmogenic risk, if any, from anchor deployment. The
horizontal and vertical forces generated (depicted as open arrows)
by arms 901 may also result in a counterforce which causes junction
section 903 to be brought toward the tissue surface (down open
arrows) and may even pull portions of junction section 903 into
tissue T, as shown in FIG. 6B. Once the anchor is fully deployed,
as in FIG. 6C, anchor 900 may be substantially embedded in the
tissue T.
[0065] Portions of tether 902 coupled to junction section 903 are
also brought closer to the surface of tissue T. Bringing tether 902
closer to tissue T may be beneficial because a greater proportion
of the cross-sectional blood flow path, as bordered by tether 902,
is preserved, which may reduce the risk that any subsequent
catheters or implanted components inserted into the heart chamber
or valve will snag or damage tether 902. Also, it may reduce the
degree of hemolysis compared to a tether that crosses the mitral
flow pathway farther from the tissue surface. Various anchor
designs and deployment methods are disclosed, for example, in U.S.
patent application Ser. Nos. 10/741,130, 10/792,681, 10/900,980,
11/255,400, and 10/901,555, which are herein incorporated by
reference in their entirety, as well as U.S. patent application
Ser. No. 11/202,474, previously incorporated by reference.
[0066] Referring now to FIGS. 7A through 7E, in one embodiment of
the invention, the guide tunnel 700 comprises a tubular body 702
with a central passageway 703 and multiple openings 704. Central
passageway 703, depicted in FIGS. 7D and 7E, permits the insertion
of a delivery catheter and the alignment of one or more retained
anchors with one or more of the openings 704 of guide tunnel 700.
Typically, openings 704 are grouped in a distal portion 706 of
guide tunnel 700, but in other embodiments, openings 704 may be
located more proximally. The lengths and configurations of the
tubular body 702 and distal portion 706 may vary depending upon a
variety of factors, including but not limited to the desired target
location, such as the subannular groove region, and the access
route, whether it is retrograde, antegrade, or requires a
transseptal puncture. In one example, distal portion 706 of guide
tunnel 700 comprises a flexible curved configuration. In some
embodiments, openings 704 are preferably aligned along the greater
curvature 708 of distal portion 706. In other embodiments, openings
704 may be aligned along the superior junction of the curved distal
portion. Similarly, guide tunnel 700 may be configured for a
cinchable implant inserted via the coronary sinus by aligning
openings 704 along the lesser curvature 710 of distal portion 706.
Distal portion 706 may optionally comprise an atraumatic tip, such
as an inflatable balloon or a tapered tip 709 comprising a material
with a low durometer. Guide tunnel 700 may be used in conjunction
with a guide catheter to facilitate positioning of a delivery
catheter at the desired anchoring sites.
[0067] In some embodiments, the openings 704 are arranged in a
linear configuration along a longitudinal length of guide tunnel
700. Although openings 704 are depicted in FIG. 7A through 7E as
having uniform dimensions, shapes, uniform spacing and angular and
linear alignment, these and other features of guide tunnel 700 may
be varied as desired. For example, if the cinchable implant
comprises anchors of different sizes and anchor spacings, the
anchor opening cross-sectional shapes and areas and relative
spacing may be designed accordingly. For example, opening 704 of
guide tunnel 700 has a generally semi-cylindrical shape (or
rectangular shape when opening 704 is viewed orthogonally), while
the aperture 528 of delivery device 520 in FIGS. 12A and 12B are
generally oval in shape. In other examples, the openings of the
guide tunnel may be squared, circular, semi-circular, triangular,
octagonal, rhomboidal, trapezoidal, crescent-shaped, or any other
shape. In still other examples, the openings may comprise slits
which may deform to allow passage of an anchor or other component.
The slits may have any of a variety of configurations, including
linear, arcuate, cross or star-shaped configurations, for
example.
[0068] FIG. 24 depicts an example of a guide tunnel 900 comprising
multiple apertures 902, 904 with a non-rectangular shapes. The
longitudinally origented edges 906 and 908 of each aperture 902 and
904 are configured so that they form a non-perpendicular angle with
respect to the transverse edges 910, 912 and 914 of the retention
elements 916 and 918, and the transverse edge 920 of the distal
section 922 of the guide tunnel 900. As depicted, the longitudinal
edge 906 of aperture 902 comprises angled sections 906a and 906b
adjacent to the retention elements 916 and 918 which are angled
toward the base 924 and 926 of the retention elements 916 and 918,
forming acute angles 928 and 930. The angle between the angled
sections of the longitudinal edges and the retention elements may
be uniform or non-uniform with respect to each other and the edges
may comprise straight, curved or other non-linear sections. The
angles 928 and 930 may be in the range of about 0 degrees to about
180 degrees, in some configurations about 5 degrees to about 85
degrees, in other configurations about 10 degrees to about 45
degrees, and still other configurations about 20 degrees to about
30 degrees, while some alternate configurations is in the range of
about 90 degrees to about 135 degrees, or about 100 degrees to
about 120 degrees. The longitudinal edge 908 of aperture 904, for
example, comprises a distal segment 908b is at a 110 degree angle
with respect to the transverse edge 920 of the distal section 922
of the guide tunnel. In some examples, an obtuse angle between a
longitudinal edge and a transverse edge of the guide tunnel may
reduce the risk of an edge catching or interfering with adjacent
anatomical structures and/or other devices or instruments inserted
into the guide tunnel. However, obtuse angles are not limited to
the distalmost apertures, or to the distal section of an aperture.
The longitudinal dimensions of the non-orthogonal sections 906a,
906b and 908b may each in the range of about 5% to about 50% of the
total longitudinal dimension of the generally longitudinal edges,
sometimes about 5% to about 25%, and other times about 10% to about
20%.
[0069] Guide tunnel 700 may be used in beating heart procedures
where it is difficult to control the position of the distal end of
a delivery catheter with respect to the target tissue. By providing
multiple openings 704, once guide tunnel 700 has been positioned at
its desired location, it need not be moved to deploy a plurality of
anchors. Instead, the delivery catheter can be manipulated within
the non-moving guide tunnel 700 to deploy the anchors through the
provided openings 704. Thus, guide tunnel 700 may reduce the risk
that during a lengthy procedure with multiple anchoring sites,
repositioning of the delivery catheter to a new target location may
dislodge the delivery catheter from hard-to-reach target sites that
are easily lost. In addition to transluminal procedures, guide
tunnel 700 may also be used with open or limited access surgeries.
In further embodiments of the invention, guide tunnel 700 may be
configured with a shorter longitudinal length and/or a more rigid
body for some surgical applications.
[0070] During the deployment of a cinchable implant, when the
anchors have been secured to their target sites, the coupling
members or one or more segments of the tether may still be looped
within the delivery catheter or guide tunnel 700. This may be
beneficial when implanting anchors in unstable body regions such as
a beating heart because with each deployment of an anchor, the
retention of a tether segment in guide tunnel 700 further secures
guide tunnel 700 to the sites where the anchors have been secured.
Once all of the anchors have been deployed, however, the retained
tether segments will need to be separated from guide tunnel 700 so
that guide tunnel 700 may be withdrawn.
[0071] In one embodiment of the invention, the retaining structures
between anchor openings 704 may be configured to releasably retain
the tether or coupling elements between the anchors. In a further
embodiment, depicted in greater detail in FIGS. 14A through 14H,
the retaining structures comprise latch structures 712 located
between two adjacent openings 704 of guide tunnel 700. Referring
back to FIG. 7B, which depicts latches 712 of guide tunnel 700
pulled away from tubular body 702, in some embodiments, latch 712
may comprise a base 714 and a free end 716. In some embodiments,
latch 712 comprises a material and/or configuration to permit some
deformation or deflection of latch 712 and for a tether or coupling
member retained between two adjacent openings 704 to pass out of
guide tunnel 700. Thus, in some embodiments, latch 712 comprises a
flexible material, but in other embodiments, one or more latches
may comprise a rigid material with a hinge joint or other type of
joint that permits latch movement. The edges or corners of the
latch structures 712 and/or openings 704 may be angled, as depicted
in FIG. 14, or may be rounded.
[0072] Referring to FIG. 14B, latch 712 may be configured to permit
control of the retention and/or release of the tether between
deployed anchors. In some embodiments, latch 712 comprises a lumen
718 that is alignable with complementary segments 720 of a lumen
located in the wall of the tubular body 702. The complementary
lumen segments 720 may be provided in a notched region 724 which is
complementary to free end 716 of latch 712. When aligned, each
adjacent lumen 718 and segment of the longitudinal lumen 720
permits the insertion of a locking element 722. Locking element 722
can releasably secure the latch 712 in the notched region 724 by
maintaining the alignment between the lumen 718 of latch 712 and
lumen segment 720 of tubular body 702, thereby restricting the
passage of a coupling member. When anchors are deployed through
openings 704 adjacent to latch 712, the tether will be retained by
latch 712.
[0073] In some embodiments, locking element 722 may have an
elongate configuration and comprise a wire thread, or ribbon formed
from metal, polymer, or combination thereof. Referring back to the
embodiment depicted in FIG. 7A, latch 712 comprise transverse
through-lumens 718 that complement the lumen segments of the
longitudinal lumen 720 of the tubular body 702, but the particular
orientations of the lumens or locking elements may vary, depending
on the desired orientation of openings 704. Lumen 718 of latch 712
need not be a through-lumen or a transversely oriented lumen with
respect to base 714 and free end 716 of latch 712. In some
embodiments, latches 712 may comprise radio-opaque material to
facilitate the positioning of a delivery catheter with respect to
guide tunnel 700. In other embodiments, radio-opaque material may
be located in or on tubular body 702 in angular position generally
opposite one or more latches 712 or elsewhere.
[0074] In some embodiments, latch 712 may not maintain the
alignment of lumen 718 with its complementary lumens 720 once
locking element 722 is removed. In these embodiments, reinsertion
or rethreading of locking element 722 back into lumen 718 may not
work in situ. In other embodiments, however, guide tunnel 700 may
be constructed such that latch 712 is biased to an alignment
position and locking element 722 may be reengaged to one or more
lumens 718, 720. To facilitate initial insertion or reinsertion of
locking element 722 into lumens 718, 720, lumens 718, 720 may be
provided with one or more tapered lumen openings 760 as depicted in
FIG. 8F.
[0075] In some embodiments, a single locking element 722 is
provided and is insertable through all lumens 718 of latch 712 and
complementary lumens 720 of tubular body 702, and the aggregate
lumen path from lumens 718 and complementary lumens 720 is
substantially linear or curvilinear. With these particular
embodiments, release of latches 712 start with the distalmost latch
and finish with the most proximal latch. In other embodiments, the
lumens and the locking element, such as the locking element 725
shown in FIG. 9B, may be configured to simultaneously release two
or more latches 712. With locking element 725, branched segments
726 of locking element 725 permit parallel release of latches
712.
[0076] Although FIG. 14B depicts an interlocking fit between
locking element 722, lumen 718 and lumen segment 720, other
retaining mechanisms may also be used. In FIG. 22A, for example, a
guide tunnel 300 with a plurality of delivery catheter apertures
302 is provided. Delivery catheter apertures 302 are separated by
retaining members 304 with an open seam or gap 306. As shown
schematically in FIG. 22B, after anchor deployment is completed,
guide tunnel 300 may be rotated or otherwise moved away from the
retained tethers 308 to permit release of tether 308 from guide
tunnel 300 through gaps 306. Guide tunnel 300 can then be separated
from the tethered anchors 310.
[0077] FIG. 23A depicts another embodiment of a guide tunnel 312,
comprising an outer guide 314 with one or more openings 316, each
configured to deliver a plurality of anchors at along a range a
length, and an inner guide within outer guide 314 comprising a
tubular body with two or more longitudinally spaced retaining
members 316. Retaining members 316 may be configured for release
with one or more locking elements, or may be configured for
displacement from a retained tether similar to the configuration of
retaining members illustrated in FIG. 22A.
[0078] FIGS. 7A to 7D illustrate an embodiment comprising latches
712 with a generally symmetrical protruding structure that lacks
sharp corners. FIGS. 8A through 8D depict other embodiments of the
invention with latches of different configurations. In FIG. 8A, for
example, the latch 762 is generally symmetrical with a larger base
and squared edges. In FIG. 8B, latch 864 is also generally
symmetrical with a larger base but with rounded edges. In FIGS. 8C
and 8D, though, latches 866 and 868, respectively are asymmetrical.
Asymmetrical configurations may be useful for facilitating
separation of an implant from the guide tunnel by angulating any
force exerted on the latch edge toward the free end of the
latch.
[0079] In other embodiments of the invention, locking element 722
may comprise an electrically conductive material that melts upon
the application of sufficient electrical current to permit the
release of latch 712. In still other embodiments, the releasable
retaining mechanism may comprise magnetic controlled locks or
electropolymers embedded in latch 712 that may be controlled with
application of current to wires embedded in tubular body 702
between latches 712 and the proximal end of guide tunnel 700.
[0080] Referring back to FIG. 7A, proximally, guide tunnel 700 may
comprise one or more access ports. One or more of the ports 728,
for example, may also be configured with a hemostatic seal to
reduce blood loss during the procedure, and or with a reversible
locking mechanism 730 to maintain the relative position between an
inserted component and guide tunnel 700. Port 728 may be used for
insertion and removal of the delivery catheter, for example. In
some embodiments, one or more ports 732, 734 may be provided to
obtain blood samples, for injection of radiographic or therapeutic
agents, or for the attachment of a pressure transducer. Another
port 736 may be provided for manipulation of locking element 722
which controls the release of latch structures 712.
[0081] The hemostatic seal may comprise any of a variety of
configurations known in the art. In some examples, the hemostatic
seal may comprise one or more slits on a septum or sealing member
which forms one or more seal flaps. Upon insertion of an instrument
or device through the sealing member, the seal flaps deform or
deflect to permit passage of the device while exerting force around
a perimeter of the device to substantially resist passage of fluid
or gas through the sealing member. Referring to FIGS. 25A to 25C,
in some examples, the sealing member 950 has a seal opening 952
comprising at least one non-linear slit 954a-d with respect to the
seal face 956 or a transverse plane of the seal axis 958. In the
depicted example, the sealing opening 952 comprises four arcuate or
spiral-shaped slits 954a-d arranged about the seal axis 958. Each
of the slits 954a-d has the same relative shape and size as the
other slits 954a-d and uniformly spaced around the axis 958, but in
other examples, a different number of slits may be provided, one or
more slits may have a different size or shape, the slits may be
non-uniformly spaced or non-symmetrically arranged, and/or may
intersect at location different from the center of the seal face
956. In FIG. 26, for example, the sealing member 980 comprises a
plurality of multi-angled slits 982a-d.
[0082] Referring back to FIGS. 25A to 25C, the slits 954a-d may
have a generally orthogonal orientation through the seal face 956,
or may be angled or skewed. In some examples, the slits 954a-d may
be generally angled with respect to the seal face 956 in the range
of about 5 degrees to about 85 degrees, in some configurations
about 10 degrees to about 60 degrees, and in other configurations
about 20 degrees to about 45 degrees. The seal face 956 or seal
member 950 may comprise any of a variety of elastic or flexible
materials, including any of a variety of silicones such as NuSil
Med-4035, Med-4820, and MED50-5338, may have a durometer in the
range of about 20 to about 80, in some examples about 15 to about
60, and in other examples about 20 to about 40. The thickness 960
of the seal face 956 may be in the range of about 0.01'' to about
0.1'', in some examples about 0.02'' to about 0.05'', and in other
examples about 0.025'' to about 0.03''. As illustrated in FIG. 25B,
the seal face 956 may be raised or offset from the body 962 of the
sealing member 950. The raised distance 964 of the raised seal face
956 may be in the range of about 0.01'' to about 0.2'', in some
configurations about 0.02'' to about 0.1'' and in other
configurations about 0.04'' to about 0.06''.
[0083] The body 962 comprises a lumen 966 in communication with the
sealing opening 952. The lumen 966 may have a uniform or
non-uniform diameter, cross-sectional area and/or cross-sectional
shape. Lumens with non-uniform diameters may taper toward or away
from the seal opening 952, and the taper may be linear or
non-linear. In some examples, the lumen 966 may have an average
diameter 968 in the range of about 0.05'' to about 0.5'' or more,
in some configurations about 0.1'' to about 0.3'', and in other
configurations about 0.15'' to about 0.2''. The lumen 966 may have
a length 970 anywhere in the range of about 0.1'' to about 1'' or
more, in some configuration about 0.2'' to about 0.5'', and in
other configurations about 0.25'' to about 0.4''. The body 962 may
have any of a variety of shapes, including cylindrical,
frustoconical, box-like or other shapes, and may be coupled to the
guide tunnel by a frame or housing.
[0084] In some embodiments, guide tunnel 700 may be used in
conjunction with a delivery catheter comprising multiple anchors
with preset spacing, similar to that depicted in FIGS. 12A and 12B.
In further embodiments, the spacing of the delivery catheter may
match the spacing of openings 704 of guide tunnel 700. This
particular combination may permit simultaneous deployment of
anchors or reduce the time spent to align the delivery catheter and
guide tunnel 700. In a preferred embodiment, a delivery catheter
with plural anchors and a guide tunnel with plural openings may be
provided in a kit with one or more other components described
herein.
[0085] In another embodiment, guide tunnel 700 further comprises an
inner guide tunnel 750 that is reversibly insertable into
passageway 703 of guide tunnel 700. In these and other embodiments
comprising inner guide tunnel 750, port 728 that is configured to
receive the delivery catheter will be located on the inner guide
tunnel 750 while guide tunnel 700 will have a port 752 configured
to receive the inner guide tunnel 750. Inner guide tunnel 750
further comprises an inner tubular body 754 with one or more
openings 756 located at the distal end 758 of the inner tubular
body 754. Opening 756 may be configured with flanking or other
configuration of radio-opaque markers that can be used to align
opening 756 of inner guide tunnel 750 with the corresponding
radio-opaque markers of latches 712. Opening 756 may comprise the
same material as inner tubular body 754. In other embodiments,
opening 756 is reinforced with a frame 806. In some embodiments,
frame 806 may comprise a polymer of higher durometer than material
comprising inner tubular body 754. In other embodiments, frame 806
may comprise a metal such as stainless steel, cobalt chromium,
platinum-iridium, or Nitinol. In further embodiments, frame 806 may
be plated with an additional metal, including but not limited to
gold. In some embodiments, frame 806 is plated with additional
material to alter its radio-opacity. Inner guide tunnel 750 may
also be configured with one or other proximal ports 734 previously
mentioned.
[0086] In some embodiments of the invention, guide tunnel 700,
inner guide tunnel 750 or the delivery catheter may include a
position sensor system to detect the relative position of inner
guide tunnel 750 and/or the delivery catheter. In one embodiment,
the position sensor system comprises a series of electrical contact
points along passageway 703 of guide tunnel 700 that can form an
electrical circuit with one or more electrical contact points
located on inner tubular body 754. Similarly, electrical contact
points in the lumen of inner guide tunnel 750 can be used to detect
the position of delivery catheters inserted therein. The position
sensor system may be used as a substitute or in conjunction with
radio-opaque markers to facilitate alignment of various components.
Other types of position sensor system are also contemplated,
including but not limited to optical and magnetic detection
mechanisms.
[0087] In some embodiments of the invention, guide tunnel 700 with
inner guide tunnel 750 may be used with delivery catheters
comprising a single anchor, or delivery catheters with multiple
anchors. In these embodiments, inner guide tunnel 750 may be used
to simplify positioning of delivery catheters with respect to
openings 704 on guide catheter 700. Inner guide tunnel 750 may also
be provided with one or more visual markings, detents, servo motor
controlled positioning or other mechanisms to facilitate anchor
delivery through openings 704. In some embodiments, inner guide
tunnel 750 may be configured, for example, to reorient end-firing
anchor delivery catheters to deploy anchors through the side
openings 705 of guide tunnel 700.
[0088] In some embodiments, guide tunnel 700 and inner guide tunnel
750 may be configured to restrict or limit any rotational movement
between the two components. Such a feature may be useful when
positioning in more difficult target locations in the body that
require considerable length, angulation and torque to reach that
may result in rotation and/or length misalignment. In one
embodiment of the invention, depicted in FIGS. 14C to 14E,
passageway 703 of distal section 706 is configured with a rail 800,
groove or other alignment structure to resist rotational movement
of inner guide tunnel 750. Rail 800 is attached at a distal end 804
and a proximal end (not shown) and permits inner guide tunnel 750
to longitudinally slide along between its two attachment points,
where rail 800 passes through slots 802 or slits formed in the
tubular body 754 of inner guide tunnel 750. In some embodiments,
the rail has a width to thickness ratio of about 5:1 to about 20:1,
preferably about 8:1 to about 16:1, and most preferably about 9:1
to about 14:1. In other embodiments, rail 800 is not attached
proximally and permits inner guide tunnel 750 to be fully withdrawn
from guide tunnel 700 and exchanged for a different inner guide
tunnel 750. Rail 800 preferably comprises materials selected to
reduce or minimize any friction or cohesion effects between the
rail and the material comprising tubular body 754 of inner guide
tunnel 750. In some embodiments, rail 800 may comprise a metal such
as stainless steel or Nitinol. In other embodiments, rail 800 or
other alignment configuration may comprise a lubricious coating
such as PTFE to reduce movement resistance of inner guide tunnel
750. In still other embodiments of the invention, rail 800 may have
a different cross sectional shape from flat band configuration
depicted in FIG. 14C, including but not limited to square,
rectangle, circle, oval or other geometric shape.
[0089] In the embodiments of the cinchable implants described
above, several embodiments of guide tunnel 700 or tunnel catheter
148 depict a single, longitudinal arrangement of alternating
identical sized openings 154 and identical retaining elements or
latches 712, but alternate configurations are also contemplated.
These alternate configurations may include, for example, two or
more distinct groups, 768, 770, 772 of openings and retaining
elements as illustrated in FIG. 10A, that may involve single or
multiple locking mechanisms that may be released in parallel, in
serial or in a mixed fashion. FIG. 10B is another embodiment of a
guide tunnel 774 comprising variable-sized openings 776, 778 or
retaining elements 780, 782, 784 and/or non-alternating retaining
elements 780, 782, 784. The configuration depicted in FIG. 10B also
demonstrates other features that may be incorporated into the
tunnel catheter 148. For example, certain materials used to provide
adequate column strength and torqueability to tunnel catheter 154
may result in retaining elements that are too stiff or bulky to
easily release the tether safely. In some examples, the spacing
between openings is such that the width of the retaining element is
greater than the length of the retaining element by about 1.times.,
or about 2.times. or about 3.times. multiple or more. To reduce the
potential of snagging or inability to pass the tether, a series of
consecutive retaining elements 780, 782, 784 having a smaller width
may be used. FIG. 10B also depicts retaining elements 786 with a
tapered base 788 to facilitate bending of retaining elements
786.
[0090] Referring again to FIGS. 14A through 14H, a more detailed
description of guide tunnel 700 is provided. FIG. 14A illustrates
distal section 706 of guide tunnel 700. Distal section 706 is
configured with a curvature configured to facilitate the placement
of anchors in the subannular groove region. Seven openings 706 are
provided along the greater curvature 708 of distal section 706. In
other embodiments, the number of openings 706 may vary from about 2
or about 3, to about 30 or more. In preferred embodiments, openings
706 may number from about 5 to about 20, while in most preferred
embodiments, openings 706 may number from about 7 to about 10. In
some embodiments, openings 706 may have a length of about 3 mm to
about 20 mm, preferably about 5 mm to 10 mm and most preferably
about 7 mm to about 8 mm. In some embodiments, openings 706 may
have a width of about 1 mm to about 10 mm, preferably about 2 mm to
about 7 mm, and most preferably about 3 mm to about 5 mm.
[0091] With reference now to FIG. 11, one embodiment of the
invention comprises an anchor delivery device 200, which suitably
includes an elongate shaft 204 having a distal portion 202
configured to deliver a plurality of anchors 210, coupled with a
tether 212, and configured for attachment to annular tissue. The
tethered anchors 210 are housed within a housing 206 of the distal
portion 202, along with one or more anchor retaining mandrels 214
and a delivery opening 208. Many variant embodiments may be made to
one or more of these features, and various parts may be added or
eliminated. Some of these variations are described further below,
but no specific variation(s) should be construed as limiting.
[0092] Housing 206 may be flexible or rigid in some variations. In
some embodiments, for example, flexible housing 206 may comprise
multiple segments configured such that housing 206 is deformable by
tensioning a tensioning member coupled to the segments. In some
embodiments, housing 206 is formed from an elastic material having
a geometry selected to engage and optionally shape or constrict the
annular tissue. For example, the rings may be formed from spring
stainless steel, super-elastic shape memory alloys such as
nickel-titanium alloys (e.g., Nitinol), or the like. In other
embodiments, the housing 206 could be formed from an inflatable or
other structure that can be selectively rigidified in situ, such as
a gooseneck or lockable element shaft, any of the rigidifying
structures described above, or any other rigidifying structure.
[0093] In some embodiments of the invention, anchors 210 are
generally C-shaped or semicircular in their undeployed form, with
the ends of the "C" being sufficiently sharpened to penetrate
tissue. Between the ends of the C-shaped anchor 210, an eyelet may
be formed for allowing slidable passage of the tether 212. To
maintain the anchors 210 in their C-shaped, undeployed state,
anchors 210 may be retained within housing 206 by two mandrels 214,
one mandrel 214 retaining each of the two arms of the C-shape of
each anchor 210. Mandrels 214 may be retractable within elongate
catheter body 204 to release anchors 210 and allow them to change
from their undeployed C-shape to a deployed shape. The deployed
shape, for example, may approximate a partial or complete circle,
or a circle with overlapping ends, the latter appearing similar to
a key ring. Such anchors are described further below, but generally
may be advantageous in their ability to secure themselves to
annular tissue by changing from their undeployed to their deployed
shape. In some variations, anchors 210 are also configured to lie
flush with a tissue surface after being deployed. By "flush" it is
meant that no significant amount of an anchor protrudes from the
surface, although some small portion may protrude.
[0094] The retaining mandrels 214 may have any suitable
cross-sectional shape, cross-sectional area, length and be made of
any suitable material, such as stainless steel, titanium,
nickel-titanium alloys (e.g., Nitinol), or the like. Some
embodiments may not include a mandrel, or may have one mandrel, two
mandrels, or more than two mandrels.
[0095] In some embodiments, the anchors 210 may be released from
mandrels 214 to contact and secure themselves to annular tissue
without any further force applied by the delivery device 200. Some
embodiments, however, may also include one or more expandable
members 208, which may be expanded to help drive anchors 210 into
tissue. Expandable member(s) 208 may have any suitable size and
configuration and may be made of any suitable material(s). Any of a
variety of mechanical and hydraulic expandable members known in the
art may be included in housing 206.
[0096] In another embodiment of the invention, shown in FIGS. 12A
and 12B, a flexible distal portion of an anchor delivery device 520
includes a housing 522 configured to house multiple coupled anchors
526 and an anchor contacting member 530 coupled with a pull cord
532. Housing 522 may also include multiple apertures 528 for
allowing egress of anchors 526. For clarity, delivery device 520 is
shown without a tether in FIG. 12A, but FIG. 12B shows that a
tether 534 may extend through an eyelet, loop or other portion of
each anchor 526, and may exit each aperture 528 to allow for
release of the plurality of anchors 526. Anchors 526 may be
relatively straight and may lie relatively in parallel with the
long axis of delivery device 522. Anchor contacting member 530,
which may comprise any suitable device, such as a ball, plate,
hook, knot, plunger, piston, or the like, generally has an outer
diameter that is nearly equal to or slightly less than the inner
diameter of housing 522. Contacting member 530 is disposed within
the housing, distal to a distal-most anchor 526, and is retracted
relative to housing 522 by pulling pull cord 532. When retracted,
anchor contacting member 530 contacts and applies force to a
distal-most anchor 526 to cause release of that anchor 526 from
housing 522 via one of the apertures 528. Contacting member 530 is
then pulled farther proximally to contact and apply force to the
next anchor 526 to deploy that anchor 526, and so on.
[0097] Retracting contacting member 530 to push anchors 526 out of
apertures 528 may help cause anchors 526 to secure themselves to
the tissue adjacent the apertures 528. Using anchors 526 that are
relatively straighter/flatter configuration when undeployed may
allow anchors 526 with relatively large deployed sizes to be
disposed in (and delivered from) a relatively small housing 522. In
one embodiment, for example, anchors 526 that deploy into a shape
approximating two intersecting semi-circles, circles, ovals,
helices, or the like, and that have a radius of one of the
semi-circles of about 3 mm may be disposed within a housing 522
having a diameter of about 6 French (2.00 mm) and more preferably
about 5 French (1.67 mm) or even smaller. Such anchors 526 may
measure about 6 mm or more in their widest dimension. In some
embodiments, housing 522 may have a diametrical dimension ("d") and
anchor 526 may have a diametrical dimension ("D") in the deployed
state, and the ratio of D to d may be at least about 3.5. In other
embodiments, the ratio of D to d may be at least about 4.4, and
more preferably at least about 7, and even more preferably at least
about 8.8. These are only examples, however, and other larger or
smaller anchors 526 may be disposed within a larger or smaller
housing 522. The dimensions of an anchor may vary depending on the
particular usage. For example, anchors used for ventriculoplasty
may permit the use of larger anchors than those used for
annuloplasty due to fewer space constraints in the main compartment
of the ventricles than in the subvalvular spaces. Furthermore, any
convenient number of anchors 526 may be disposed within housing
522. In one variation, for example, housing 522 may hold about 1 to
about 20 anchors 526, and more preferably about 3 to about 10
anchors 526. Other variations may hold more anchors 526.
[0098] Anchor contacting member 530 and pull cord 532 may have any
suitable configuration and may be manufactured from any material or
combination of materials. In alternative embodiments of the
invention, contacting member 530 may be pushed by a pusher member
to contact and deploy anchors 526. Alternatively, any of the anchor
deployment devices and methods previously described may be
used.
[0099] Tether 534, as shown in FIG. 12B, may comprise any of the
tethers 534 or tether-like devices already described above, or any
other suitable device. Tether 534 is generally attached to a
distal-most anchor 526 at an attachment point 536. The attachment
itself may be achieved via a knot, weld, adhesive, or by any other
suitable attachment mechanism. Tether 234 then extends through an
eyelet, loop or other similar configuration on each of the anchors
526 so as to be slidably coupled with the anchors 526. In the
particular embodiment shown, tether 534 exits each aperture 528,
then enters the next-most-proximal aperture, passes slidably
through a loop on an anchor 526, and exits the same aperture 528.
By entering and exiting each aperture 528, tether 534 allows the
plurality of anchors 526 to be deployed into tissue and cinched.
Alternate embodiments of housing 522, anchors 526 and tether 534
may also be used. For example, housing 522 may include a
longitudinal slit through which tether 534 may pass, thus allowing
tether 534 to reside wholly within housing before deployment.
[0100] FIGS. 13A to 13D represent various views of one embodiment
of a delivery catheter 1200 that can be used to deliver one or more
anchors to a target site. As shown in FIG. 13A, delivery catheter
1200 has a distal region 1204 including a tip 1202, an
anchor-holding region 1206 including a primary lumen 1208, an
intermediate region 1210 including both primary lumen 1208 and a
secondary lumen 1212, and a proximal region 1214 including primary
lumen 1208. An anchor 1216 is disposed within primary lumen 1208,
in the anchor-holding region 1206. While only one anchor is shown
in the anchor-holding region of this embodiment, in other
embodiments of the invention, the delivery catheters may include an
anchor-holding region that is adapted to hold multiple anchors.
Similarly, while the variation shown in FIGS. 13A to 13D depict
anchors adapted to be deployed from distal region 1204 of delivery
catheter 1200, it should be understood that the anchors may be
deployed from any suitable region of delivery catheter 1200, as
desirable. For example, if desirable, the anchor may be delivered
out of a side port or hole on the delivery catheter.
[0101] As shown in FIGS. 13A to 13D, a tether 1218 may be threaded
into a slot 1219 of tip 1202 (shown in FIGS. 13C and 13D), and
through an eyelet 1226 of anchor 1216. After extending through
eyelet 1226, tether 1218 exits primary lumen 1208, and extends
along an exterior surface 1221 of delivery catheter 1200 for the
remainder of the length of the anchor-holding region, as shown in
FIG. 13C. Tether 1218 then enters secondary lumen 1212, and extends
through the length of secondary lumen 1212, exiting secondary lumen
1212 at an end of distal region 1214. An actuator 1220 is slidably
disposed within primary lumen 1208, and can be used to push or
deploy anchor 1216 out of the primary lumen 1208. Actuator 1220 is
in the form of a pushable generally tubular member, although other
forms of actuators may be used. For example, in some variations, a
solid rod may be used as an actuator. Once a sufficient distal
portion of anchor 1216 has been displaced out of primary lumen
1208, the self-expanding properties of anchor 1216 may cause the
biased distal ends to expand outwardly and cause the remainder of
anchor 1216 to "spring out" or "shoot out" of distal end 1202 and
facilitate tissue piercing by anchor 1216. Eyelet 1226 will also
engage tether 1218 as anchor 1216 exits delivery catheter 1200. In
other embodiments, actuator 1220 may be spring-loaded or biased to
facilitate tissue piercing. Additional embodiments of the delivery
catheter are described in U.S. patent application Ser. No.
11/202,474, which was previously incorporated by reference.
[0102] Delivery catheter 1200 may optionally comprise a retrieval
member, such as a retrieval line or filament 1222 that is looped
around eyelet 1226 of anchor 1216 and threaded proximally back
through delivery catheter 1200. Retrieval filament 1222 is pulled
of delivery catheter 1200 by eyelet 1226 when anchor 1216 is
deployed. Retrieval filament 1222 may be used to pull back anchor
1216 into delivery catheter 1200 should anchor 1216 misfire and
fail to engage body tissue. If anchor 1216 is successfully
deployed, one end of retrieval filament 1222 may be pulled out from
eyelet 1226 to release anchor 1216 from retrieval filament
1222.
[0103] With reference to FIGS. 15A to 15F, one embodiment of the
invention comprises a method for applying a plurality of tethered
anchors 526 to the annular tissue of a heart. As shown in FIG. 15A,
an anchor delivery device 520 is first contacted with the valve
annulus VA or annular tissue such that openings 528 are oriented to
deploy anchors 526 into the tissue. Such orientation may be
achieved by any suitable technique. In one embodiment, for example,
a housing 522 having an elliptical cross-sectional shape may be
used to orient openings 528. Contact between housing 522 and the
annular tissue may be enhanced by expanding expandable member 524
to wedge housing 522 within the deepest portion of the subannular
groove region.
[0104] Generally, delivery device 520 may be advanced into any
suitable location for treating any valve or body tissue by any
suitable advancing or device placement method. For example, in one
embodiment a guide member is first advanced in a retrograde fashion
through an aorta, typically via access from a femoral artery. The
guide member is passed into the left ventricle of the heart and
thus into the space formed by the mitral valve leaflets, the left
ventricular wall and chordae tendineae of the left ventricle. Once
in this space, the guide member is advanced along a portion (or
all) of the circumference of the mitral valve. A sheath 540 is
advanced over the guide member within the space below the valve
leaflets, and the guide element is removed through sheath 540. In
some embodiments, the guide member may comprise a steerable guide
catheter. Anchor delivery device 520 may then be advanced through
the sheath to a desired position within the space, and sheath 540
may be removed. In other embodiments, a tunnel catheter 148 (shown
in ghost) is passed through the sheath to provide additional
stability and to facilitate positioning of the delivery device
520.
[0105] As shown in FIG. 15B, when delivery device 520 is positioned
in a desired location for deploying anchors 526, anchor contacting
member 530 is retracted to contact and apply force to a most-distal
anchor 526 to begin deploying anchor 526 through aperture 528 and
into the valve annulus VA or annular tissue. FIG. 15C shows anchor
526 further deployed out of aperture 528 and into valve annulus VA
or annular tissue. FIG. 15D shows the valve annulus VA
transparently so that further deployment of anchors 526 can be
seen. As shown, in one embodiment, anchors 526 include two tips
that move in opposite directions upon release from housing 522 and
upon contacting the valve annulus VA or annular tissue. Between the
two tips, an anchor 526 may be looped or have any other suitable
eyelet or other device for allowing slidable coupling with a tether
534.
[0106] Referring now to FIG. 15E, anchors 526 are seen in their
fully deployed or nearly fully deployed shape, with each tip (or
"arm") of each anchor 526 having curved to form a circle or
semi-circle. In some variations anchors 526 may have any other
suitable deployed and undeployed shapes, as described more fully
above. FIG. 15F shows anchors 526 deployed into the valve annulus
VA or annular tissue and coupled to tether 534, with the
distal-most anchor 526 coupled to tether 524 at attachment point
536. At this stage, tether 534 may be tensioned to tighten the
annular tissue, thus reducing valve regurgitation. In some
embodiments, valve function may be monitored by means such as
echocardiogram and/or fluoroscopy, and tether 534 may be tensioned,
loosened, and adjusted to achieve a desired amount of tightening as
evident via the employed visualization technique(s). When a desired
amount of tightening is achieved, the implant may be fixed using
any of a variety of termination devices and methods.
[0107] For example, in one embodiment, tensioning tether 534,
attaching tether 534 to most-proximal anchor 526, and cutting
tether 534 are achieved using a termination device (not shown). The
termination device may comprise, for example, a catheter
advanceable over tether 534 that includes a cutting member and a
nickel-titanium alloy (e.g., Nitinol) knot or other attachment
member for attaching tether 534 to most-proximal anchor. The
termination catheter may be advanced over tether 534 to a location
at or near the proximal end of the tethered anchors 526. It may
then be used to apply opposing force to the most-proximal anchor
526 while tether 534 is tensioned. Attachment and cutting members
may then be used to attach tether 534 to most-proximal anchor 526
and cut tether 534 just proximal to most-proximal anchor 526. Such
a termination device is only one possible way of accomplishing the
cinching, attachment and cutting steps, and any other suitable
device(s) or technique(s) may be used. Additional devices and
methods for terminating (e.g., cinching and fastening) may be
found, for example, in U.S. patent application Ser. No. 11/232,190,
previously incorporated by reference, and U.S. patent application
Ser. Nos. 11/270,034, and 11/875,774, both of which are herein
incorporated by reference in their entirety. In some embodiments,
the termination device is located in the same heart chamber as the
remaining portions of the implant, which permits the implant to be
wholly implanted in a single heart chamber. In other embodiments,
however, a portion of the implant passes transmurally through a
septal wall or an outer wall of a heart chamber. In these
embodiments, the termination member and optionally one or more
anchors may be located in a different heart chamber.
[0108] In some embodiments, it may be advantageous to deploy a
first number of anchors 526 along a first portion of annular
tissue, cinch the first anchors to tighten that portion of the
annular tissue, move the delivery device 520 to another portion of
the annular tissue, and deploy and cinch a second number of anchors
526 along a second portion of the annular tissue. Such a method may
be more convenient, in some cases, than extending delivery device
520 around all or most of the circumference of the annular tissue,
and may allow a shorter, more maneuverable housing 522 to be
used.
[0109] With reference to FIGS. 16A and 16B, a diagrammatic
representation of another embodiment of the invention, comprising
coupled anchors is shown. Here, anchors 510 are coupled to a
self-deforming or deformable coupling member or backbone 505. This
backbone 505 is another embodiment of a tether. The backbone 505
may be fabricated, for example, from nickel-titanium alloys (e.g.,
Nitinol), spring stainless steel, or the like, and may have any
suitable size or configuration. In one embodiment, as in FIG. 16A,
backbone 505 is shaped as a generally straight line when held in an
undeployed state, such as when restrained within a housing of an
anchor deliver device. When released from the delivery device,
backbone 505 may change to a deployed shape having multiple bends,
as shown in FIG. 16B. By bending, backbone 505 shortens the
longitudinal distance between anchors, as demonstrated by the
solid-tipped arrows in FIG. 16B. This shortening process may act to
reshape any tissue or structure into which anchors 510 have been
secured. Thus, anchors 510 coupled to backbone 505 may be used to
reshape annular tissue or any other tissue without using a separate
tether or applying tethering force. In other embodiments, an
elastic tether may be used as the backbone 505. In still other
embodiments, backbone may also be coupled with a termination member
to further cinch the annular tissue. In such an embodiment, the
backbone 505 is adapted to be at least partially conformable or
cinchable, such that when force is applied to anchors 510 and
backbone 505 via a tether, backbone 505 buckles or compresses
further to allow further cinching of the annular tissue.
[0110] Although the preferred access route to the subannular groove
region 104 or subvalvular space 106 is a retrograde route through
the aorta A to the heart H, other access routes may also be used.
Access to the heart H may also be transthoracic, with a delivery
device being introduced into the heart via an incision or port in
the heart wall. Even open heart surgical procedures may benefit
from the methods and devices described herein. In some embodiments
of the invention, hybrid access involving a combination of access
methods described herein may be used. In one specific example, dual
access to a valve may be achieved with a combination of venous and
arterial access sites. User manipulation of both ends of a
guidewire placed across a valve may improve positioning and control
of the catheter and the implants. In other examples of hybrid
access, both minimally invasive and surgical access is used to
implant one or more cardiac devices.
[0111] Other embodiments of the invention also include treatment of
the tricuspid valve annulus, tissue adjacent the tricuspid valve
leaflets TVL, or any other cardiac or vascular valve. Thus,
although the description herein discloses specific examples of
devices and methods of the invention for mitral valve repair, the
devices and methods of the invention may be used in any suitable
procedure, both cardiac and non-cardiac. For example, in other
embodiments of the invention, the mitral valve reshaping devices
and procedures may be used with the tricuspid valves also, and
certain embodiments may also be adapted for use with the pulmonary
and aortic valves. Likewise, the other examples provided below are
directed to the left ventricle, but the devices and methods may
also be adapted by one of ordinary skill in the art for use in the
right ventricle or either atrium. The devices and methods may also
be used with the great vessels of the cardiovascular system, for
example, to treat aortic root dilatation.
[0112] Access to the other chambers of the heart may be performed
through percutaneous or venous cut-down access, including but not
limited to transjugular, subclavicular and femoral vein access
routes. When venous access is established, access to the right
atrium RA, the right ventricle RV, the tricuspid valve TV and other
right-sided cardiac structures can occur. Furthermore, access to
left-sided heart structures, such as the left atrium LA, left
ventricle LV, mitral valve and the aortic valve, may be
subsequently achieved by performing a transseptal puncture
procedure. Referring to FIG. 17 with a heart H is shown in cross
section, transseptal puncture is traditionally performed using a
Mullins introducer sheath with a Brockenbrough curved needle
through the interatrial septum to access the left atrium LA, but
any of a variety of other transseptal puncture devices or kits may
also be used. After puncturing through the left atrium LA,
supravalvular access to the mitral valve is achieved. Antegrade
access to the left ventricle LV can also occur by crossing the
mitral valve. Similarly, access from the right ventricle RV to the
left ventricle LV may be obtained by transseptal puncture of the
ventricular septum. In still other embodiments, a catheter device
may access the coronary sinus and a valve procedure may be
performed directly from the sinus.
[0113] Surgical approaches that may be used have been described
above but also include but are not limited to transcatheter
procedures made through surgical incisions in the aorta or
myocardium. In one particular embodiment, depicted in FIG. 18, a
transapical approach with a surgical delivery device 114 is
utilized, to provide a more linear route to the subvalvular space
106. The transapical approach also reduces potential effects of a
myocardial incision on cardiac output, as the apical wall 112
typically contributes less mechanical effect on left ventricular
ejection fraction compared to other sections of the myocardial
wall.
[0114] In addition to performing valve annuloplasty with the
multi-opening guide tunnel, other uses, including cardiac and
non-cardiac applications, are contemplated within the scope of the
invention. In one embodiment of the invention, reconfiguration of
the subvalvular apparatus with a cinchable implant delivered by a
multi-opening delivery tool with a releasable tether retaining
mechanism is contemplated. For example, a plurality of tethered
anchors may be secured to the myocardium adjacent the papillary
muscle and then cinched to tension the myocardium and cause
repositioning of one or more papillary muscles.
[0115] In other embodiments, the reshaping of a ventricle may be
performed using a multi-opening guide tunnel with a releasable
tether retaining mechanism, along any of a variety of dimensions or
vectors. For example, referring to FIG. 19, in some embodiments of
the invention, the reshaping of a ventricle or a valve may occur
with respect to the diameter B or the circumference C about a valve
orifice. In one preferred embodiment, the diameter B and the
circumference C with respect to the subannular groove region 104 of
a ventricle is reshaped. In addition to the reshaping of to
valvular structures, reshaping can also be performed with respect
to the non-valvular structures of a heart chamber. For example, one
or more of the diameters or circumferences of the ventricle may be
reshaped. As shown in FIG. 19, the diameter B' and the
circumference C' of the ventricle located generally at or above the
papillary muscles may be reshaped. The diameter B'' and
circumference C'' of the ventricle at or below the papillary
muscles may also be reshaped. The orientation of the diameter and
circumference that is reshaped or assessed can vary, but in some
embodiments, the diameter or circumference may be in a generally
perpendicular orientation with respect to a longitudinal axis of a
ventricle. One of skill in the art will understand that the
longitudinal axis may be characterized in a number of ways,
including but not limited to a longitudinal axis from a valve
orifice to an apex of a heart chamber, or from the apex of a heart
chamber to a point that generally splits the ventricular volume in
half. Similarly, some of the implantation dimensions or vectors may
also be oriented with respect to the anterior-posterior axis or the
septo-lateral axis of the heart chamber.
[0116] Referring to FIG. 20, in some embodiments, the myocardium
along vectors A, D between a papillary muscle and a valve leaflet
may be reshaped. Vectors D or A may be between a papillary muscle
and its associated valve leaflet, or between a papillary muscle and
an unassociated valve leaflet, respectively. Although the vectors
A, D depicted in FIG. 20 are shown from the tip of the papillary
muscle, these pathways may also be assessed from the base of the
papillary muscle. Similarly, myocardial pathways including a valve
leaflet may be assessed from the distalmost section, the middle or
the base of the valve leaflet. In other embodiments, the reshaping
of the heart may occur between the apex of a heart chamber and one
or more valves. For example, reshaping may occur along the vector E
between the outlet valve and the apex of a heart chamber, and/or
along the pathway F between the inlet valve and the apex.
[0117] In FIG. 21, for example, a multi-opening guide tunnel 850
with latches 852 is used to place a cinchable implant 854 along
vector E from FIG. 20. To implant a ventricular device in a beating
heart, in some embodiments of the invention one end of the implant
is preferably first attached to a less mobile portion of the
ventricle chamber. The distal end 856 of the implant 854 is first
secured to the apical region 858 of the left ventricle LV. Once the
distal end 856 of the implant 854 is stabilized, guide tunnel 850
can be stabilized using the secured distal end 854 and provide
increased stability during the procedure by releasably retaining
portions of the tether 860 as the remaining anchors are
deployed.
[0118] While this invention has been particularly shown and
described with references to embodiments thereof, it will be
understood by those skilled in the art that various changes in form
and details may be made therein without departing from the scope of
the invention. For all of the embodiments described above, the
steps of the methods need not be performed sequentially.
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