Note: Descriptions are shown in the official language in which they were submitted.
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SYSTEM AND METHOD FOR HEART VALVE ANCHORING
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of, and incorporates by reference thereto
in its
entirety, U.S. Provisional Patent Application Serial No. 62/010,680, filed on
June 11, 2014.
Further, each of the following is hereby incorporated by reference thereto in
its
entirety: U.S. Patent Application Serial No. 14/321,476, filed July 1, 2014,
U.S. Patent
Application Serial No. 14/301,106, filed June 10, 2014, U.S. Patent
Application Serial No.
13/843,930, filed March 15, 2013, PCT Application No. PCT/U514/30868, filed
March 17,
2014, U.S. Patent Application Serial No. 13/010,769, filed January 20, 2011,
U.S. Provisional
Patent Application Serial No. 61/296,868, filed on January 20, 2010, U.S.
Patent Application
Serial No. 13/010,766, filed on January 20, 2011, U.S. Patent Application
Serial No.
13/010,777, filed on January 20, 2011, and U.S. Patent Application Serial No.
13/010,774,
filed on January 20, 2011.
FIELD OF THE INVENTION
The present invention relates to a system and method of percutaneous heart
valve
replacement, including anchoring the heart valve replacement into tissue.
BACKGROUND INFORMATION
Heart valve replacements have been developed to counter heart valve failure,
either
from heart valve regurgitation (i.e., the failure of the heart valve to
properly close), or from
heart valve stenosis (i.e., the failure of the heart valve to properly open).
Though early efforts
at heart valve repair and replacement included open surgery, more recent
developments have
included percutaneous surgical applications.
Percutaneous heart valve repair, however, has shown certain disadvantages. For
example, percutaneous repair involves modified surgical techniques, which can
limit the
benefits of the procedure. Annular rings may lack effectiveness, and include
risks of erosion,
perforation, and coronary artery thrombosis. Edge-to-edge repair can be
technically
demanding, and may lack long term durability. Depending upon the particular
valve failure,
combinations of different repair techniques may be necessary, further
complicating the
procedure and limiting its effectiveness.
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In contrast, heart valve replacement has provided certain advantages, lim
risks associated with heart valve repair, and applying to a broader scope of
patients. Open
surgery solutions for heart valve replacement, however, carry significant
risks to the patient.
Therefore, a less invasive, percutaneous heart valve replacement is needed.
Existing percutaneous solutions include U.S. Patent No. 7,621,948, describing
a
percutaneously inserted heart valve prosthesis, which can be folded inside a
catheter for
delivery to the implant location. Another percutaneous solution is available
from CardiAQ
Valve Technologies, Inc., described in U.S. Patent Application Publication No.
2013/0144378. Other percutaneous prosthetic valves include Neovasc Tiara,
Valtech
Cardiovalve, ValveXchange, Lutter Valve, and valves from Medtronic, Inc. and
Edwards
Lifesciences Corporation.
In providing a percutaneous heart valve replacement, challenges include
providing an
implant that may be folded into a catheter for delivery, and can emerge from
the catheter to
fit properly into the implant site and serve its function as a valve. The
implant valve must
therefore be small enough to be folded into the catheter, but must be large
enough, upon
implantation, to provide the functions of the valve, without being so large as
to obstruct
ventricular flow.
Moreover, fixing the heart valve implant to the implant site may be
challenging, as the
implant site may form an irregular shape, may lack calcium to secure the
valve, or may cause
difficulty in fixing the implant valve with the proper orientation.
There is a need for a percutaneous heart valve solution to sufficiently and
effectively
address these challenges.
SUMMARY
In accordance with example embodiments of the present invention, a device for
delivering, implanting, and fixing to tissue a heart valve replacement
prosthetic is provided.
The device may include a ring, which may be pliable enough to be folded into a
small space,
such as the cavity of a catheter. The ring may be elastic, so as to
automatically expand upon
its release from its folded position in a catheter. Where an implant site is
irregularly shaped,
the elasticity of the ring permits the ring to form to the shape of the
implant site. The device
may further include one or more leaflets connected to the ring, effective to
block fluid flow in
a first fluid flow direction and to permit fluid flow in a second fluid flow
direction.
The system of the present invention may include an applicator, including an
applicator shaft passing through the ring, and terminating at its distal end
in one or more
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spring arms. The spring arms may connect the distal end of the applicator
shaft
such that the spring arms exert a spring force against the ring, pushing the
ring radially
outward. Each spring arm is separately connected to the ring, so that, in the
case of a
plurality of spring arms, each spring arm may each respond individually to an
irregularly
shaped implant site, allowing the ring to form to the shape of the implant
site, and provide a
better seat for the prosthetic heart valve.
The prosthetic may be delivered to the implant site percutaneously, for
example, by a
catheter, into which the prosthetic may be folded. Once delivered to the
implant site, the
prosthetic may be pushed through a distal end of the catheter, such that the
ring is allowed to
expand. The prosthetic may then be implanted in the implant site, with the
elasticity of the
ring and the independent spring arms permitting the prosthetic to form to any
irregular shape
of the implant site.
Once implanted, in an example embodiment of the present invention, a driver
may be
used to drive anchors through the ring, and into the tissue of the implant
site, fixing the
prosthetic to the tissue of the implant site. The driver may be configured to
drive one or more
anchors into one or more positions about the ring, and may index the driving
of anchors in
line with each spring arm. Once the prosthetic has been fixed to the implant
site, the
applicator may be withdrawn, leaving the prosthetic fixed in place. The
prosthetic may have
a smaller width or diameter than the width or diameter of the implant site,
such that, once the
anchors have been driven into the surrounding tissue of the implant site, the
tissue of the
implant site may be drawn toward the smaller prosthetic, to meet the exterior
shape of the
prosthetic.
In this manner, the prosthetic valve may be securely fixed to the implant
site, to more
sufficiently and effectively improve valve function. The prosthetic may take a
variety of
shapes. The shape of the prosthetic to be used for a particular application
may be selected
based on the particular geometric needs of the particular application.
In accordance with example embodiments of the present invention, a surgical
device
includes an applicator having an applicator shaft passing through the ring and
terminating at a
distal end having one or more spring arms connecting the distal end of the
applicator shaft to
the ring, such that a proximal force applied to the applicator shaft is
transferred to the one or
more spring arms and to the pliable ring, and a driver having a guide situated
annularly about
the applicator shaft, and at least one firing arm including at least one
anchor outlet, the driver
configured to slide between a proximal position and a distal position along
the applicator
shaft, wherein the at least one firing arm is in hinged communication with the
driver, such
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that in the proximal position of the driver the at least one anchor outlet is
situate
with the applicator shaft, and in the distal position of the driver the at
least one anchor outlet
is directed toward the pliable ring, and the driver is configured to exert a
driving force on at
least one anchor to drive the anchor into the pliable ring.
The prosthetic valve may be delivered to an implant site by a catheter, the
pliable ring
being folded for insertion into the catheter and expandable once pushed from a
distal end of
the catheter. The prosthetic valve may be implanted at an implant site, and
the driver may be
configured to drive the anchor at least partially through the ring and into
tissue surrounding
the implant site.
The anchor may include a distal end tapered to a distal tip configured to
pierce tissue,
at least one barb extending proximally and radially outwardly from the distal
end to a free
end including a radially exterior surface and a radially interior surface, and
a flexible stem
extending proximally from the distal end, flexible with respect to the at
least one barb and
distal tip. The flexible stem may be configured to flex in cooperation with a
force exerted on
the anchor. The at least one anchor may be configured to engage with the
tissue and resist
proximal movement.
The driver may be configured to rotate about the applicator shaft, and further
may be
configured to index the driving of anchors in line with each spring arm.
The applicator may be removable from the prosthetic valve by exertion of a
distal
force on the applicator shaft to release the spring arms from engagement with
the pliable ring,
and exertion of a proximal force on the applicator shaft to draw the
applicator proximally
through the prosthetic valve.
The firing arm may be hinged to the driver at a proximal end of the firing
arm, or may
be hinged to the driver at a distal end of the firing arm.
In accordance with example embodiments of the present invention, a surgical
device
includes a driver having a distal end, at least one firing arm in hinged
communication with
the distal end of the driver, each including at least one anchor outlet,
having a refracted
position parallel to the driver, and a firing position in which the firing arm
is directed
proximally and radially outward, a guide situated within the driver, and a
firing mechanism
connected to the guide and configured to transfer force from the guide in the
proximal and
radially outward direction of the firing arm in the firing position.
In accordance with example embodiments of the present invention, a surgical
device
includes a pliable ring collapsible for insertion into a catheter and
expandable upon ejection
from the catheter, an applicator having one or more spring arms configured to
exert a force
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on the ring to ring the ring into apposition with tissue, and a driver having
at lea
arm configured to drive at least one anchor into the ring and the tissue to
affix the ring to the
tissue. The spring arms may further be configured to conform the ring to the
contours of the
surrounding tissue. The spring arm may exert the force on the ring while the
driver drives the
at least one anchor into the ring and the tissue to affix the ring to the
tissue.
The surgical device may include an applicator shaft passing through the ring
and
terminating in the one or more spring arms connecting the distal end of the
applicator shaft to
the ring, such that a proximal force applied to the applicator shaft is
transferred to the one or
more spring arms and to the pliable ring, and the firing arm may be in hinged
communication
with the driver, having a retracted position in which the firing arm is in
parallel with the
applicator shaft, and a firing position in which the firing arm is directed
toward the ring.
The driver may include a plurality of firing arms, and the plurality of firing
arms may
fire a plurality of anchors simultaneously.
The firing position may be perpendicular to the applicator shaft. The firing
position
may also be less than 90 degrees from the retracted position.
The firing arm may be hinged to the driver at a proximal end of the firing
arm, or may
be hinged to the driver at a distal end of the firing arm.
Further features and aspects of example embodiments of the present invention
are
described in more detail below with reference to the appended Figures.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is an illustration of the heart valve replacement prosthetic, the
applicator
shaft, the spring arms, and the driver, in accordance with an example
embodiment of the
present invention.
Figure 2 is an illustration of the heart valve replacement prosthetic, the
applicator
shaft, and the spring arms, in accordance with an example embodiment of the
present
invention.
Figure 3 is an illustration of the heart valve replacement prosthetic, the
applicator
shaft, the spring arms, and the driver, in accordance with an example
embodiment of the
present invention.
Figure 4 is an illustration of the heart valve replacement prosthetic, the
applicator
shaft, the spring arms, and the driver, in accordance with an example
embodiment of the
present invention.
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Figure 5 is an illustration of the heart valve replacement prosthetic, the a
shaft, the spring arms, and the driver, in accordance with an example
embodiment of the
present invention.
Figure 6 is an illustration of the heart valve replacement prosthetic, the
applicator
shaft, the spring arms, and the driver, in accordance with an example
embodiment of the
present invention.
Figure 7 is an illustration of the heart valve replacement prosthetic, the
applicator
shaft, the spring arms, and the driver, in accordance with an example
embodiment of the
present invention.
Figure 8 is an illustration of the heart valve replacement prosthetic, the
applicator
shaft, the spring arms, and the driver, in accordance with an example
embodiment of the
present invention.
Figure 9 is an illustration of the heart valve replacement prosthetic in
accordance with
an example embodiment of the present invention.
Figure 10 is an illustration of the heart valve replacement prosthetic in
accordance
with an example embodiment of the present invention.
Figure 11 is an illustration of an anchor in accordance with an exemplary
embodiment
of the present invention.
Figure 12 is an illustration of an anchor in accordance with an exemplary
embodiment
of the present invention.
Figure 13 is an illustration of the driver of the heart valve replacement
prosthetic in
accordance with an example embodiment of the present invention.
Figure 14 is an illustration of a cross-sectional view of the driver of the
heart valve
replacement prosthetic in accordance with an example embodiment of the present
invention.
Figure 15 is an illustration of the driver of the heart valve replacement
prosthetic in
accordance with an example embodiment of the present invention.
Figure 16 is an illustration of a cross-sectional view of the driver of the
heart valve
replacement prosthetic in accordance with an example embodiment of the present
invention.
Figure 17 is an illustration of the driver of the heart valve replacement
prosthetic in
accordance with an example embodiment of the present invention.
Figure 18 is an illustration of a cross-sectional view of the driver of the
heart valve
replacement prosthetic in accordance with an example embodiment of the present
invention.
Figure 19 is an illustration of the driver of the heart valve replacement
prosthetic in
accordance with an example embodiment of the present invention.
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Figure 20 is an illustration of a cross-sectional view of the driver of the 1-
replacement prosthetic in accordance with an example embodiment of the present
invention.
DETAILED DESCRIPTION
As set forth in greater detail below, example embodiments of the present
invention
allow for the reliable and effective delivery, implantation, and fixation of a
heart valve
replacement prosthetic, such that the prosthetic can effectively address heart
valve failure.
An exemplary embodiment of the present invention is present in Figure 1.
Figure 1
illustrates heart valve replacement prosthetic 1 having ring 10, which, in an
exemplary
embodiment, may be elastic. Figure 1 further illustrates applicator 20 having
applicator shaft
21 and spring arms 22. Spring arms 22 may be affixed to the distal end of the
applicator shaft
21, and may connect the distal end of the applicator shaft 21 to the ring 10
of the replacement
prosthetic 1. Figure 1 further illustrates driver 40, as will be described in
more detail below.
As will be generally understood, as described by, for example, U.S. Patent No.
7,621,948, the entirety of which is hereby incorporated by reference as if
fully disclosed
herein, the replacement prosthetic 1 of the present invention may be delivered
to an implant
site by first collapsing the replacement prosthetic 1 into a collapsed or
folded position, such
that the prosthetic fits within a cavity of a catheter. The catheter,
including the collapsed or
folded prosthetic, is advanced percutaneously to an implant site. Once the
distal end of the
catheter is adjacent to the implant site, the collapsed prosthetic may be
pushed or forced
through the distal end of the catheter.
Heart valve replacement prosthetic 1 may be formed of compliant, elastic
material
such as deformable plastic or nitinol, such that once the collapsed prosthetic
emerges from
the distal end of the catheter, the ring 10 may elastically return to an
uncollapsed, or
expanded formation, as illustrated in Figures 1 to 10. The prosthetic 1,
including ring 10,
may be maneuvered in the implant site, where it may be pressed into position
in the implant
site.
As further illustrated in Figures 1 to 10, ring 10 may, in an exemplary
embodiment of
the present invention, take on the shape of the implant site, which may be an
irregular shape
(e.g., non-circular). In the exemplary embodiments illustrated in Figure 1 to
10, the ring 10 is
formed to a non-circular, irregular shape. In this manner, the heart valve
replacement
prosthetic of the present invention may be adapted to a wide variety of
implant sites, to
address a wide variety of heart valve failures.
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As illustrated in Figure 2, heart valve replacement prosthetic 1 further in
leaflets 30, which perform the valve function. Leaflets 30 are connected to
ring 10, and are
further held in proper position by valve struts 31. Leaflets 30 are configured
to prevent the
flow of fluid in a first fluid flow direction, and to permit the flow of fluid
in a second fluid
flow direction.
Figures 2 through 8 illustrate an exemplary embodiment of the fixing of the
replacement prosthetic 1 to the tissue of the implant site.
As illustrated in Figure 2, replacement prosthetic 1 is expanded from the
catheter,
with ring 10 in a nearly fully expanded formation. Applicator shaft 21 extends
from the
proximal direction through and to the distal side of the ring 10. Spring arms
22 are connected
to the distal end of the applicator shaft 21, such that the distal end of the
applicator shaft 21
forms the apex of a conical shape formed by the spring arms 22 about the axis
of the
applicator shaft 21. Once delivered to the implant site, applicator shaft 21
may be used to
press ring 10 into the tissue of the implant site, by pulling the applicator
shaft 21 in a
proximal direction, such that the force in the proximal direction is
transferred to the spring
arms 22, which in turn exert a force in a proximal and radial direction
against the ring 10.
Because the spring arms include spring elements 23, such as springs or spring-
like ribbons,
each spring arm is flexible to absorb force independently of the other spring
arms. In this
manner, ring 10 is further able to achieve an irregular shape, to meet the
shape of any implant
tissue. Figures 2 to 8 illustrate various spring arms 22 being extended or
compressed to a
different degree.
As illustrated in Figure 3, once the prosthetic 1 is in place at the implant
site, driver
40 may be actuated to fasten the ring 10 to the tissue of the implant site.
Driver 40 includes
firing arm 41, having anchor outlets 42, and a guide 43. Driver 40 may be
operated to slide
or otherwise move along the applicator shaft 21. Guide 43 and firing arm 41
may be situated
on opposite sides of the applicator shaft 21, as illustrated in Figure 3.
As illustrated in Figure 4, driver 40 is moved to the distal end of the
applicator shaft
21, where the applicator shaft 21 meets the spring arms 22.
As illustrated in Figure 5, firing arm 41 is configured to rotate from a
position aligned
with the axis defined by the applicator shaft 21 to a position directed
radially away from the
applicator shaft 21, so that the anchor outlets 42 of the firing arm are
directed towards the
ring 10.
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As illustrated in Figure 6, firing arm 41 may be configured to drive anch,
through anchor outlets 42. Anchors 50 may be driven through ring 10, and into
surrounding
tissue of the implant site, fixing or fastening the ring 10 to the tissue of
the implant site.
As illustrated in Figure 7, once anchors 50 are driven into ring 10 and the
surrounding
tissue, firing arm 41 may be rotated back into alignment with the axis defined
by the
applicator shaft 21, so that the driver 40 may be retracted from the distal
end of the applicator
20, as illustrated in Figure 8.
In an exemplary embodiment of the present invention, the driving of anchors 50
may
be repeated by driver 40 and firing arm 41, so as to drive anchors 50 around
the ring 10. A
plurality of anchors 50 may be loaded into a cartridge or tray of anchors,
such that additional
anchors may be loaded into a position to be driven into ring 10 and the
surrounding tissue.
Driver 40 may index the driving of each anchor 50 to the position of each
spring arm 22
about the periphery of the ring 10. In the alternative, applicator shaft 21
may have grooves or
other markings to which driver 40 may index the driving of each anchor 50.
As illustrated in Figure 9, heart valve replacement prosthetic 1 is shown
alone, absent
applicator 20, driver 40, or anchors 50.
Figure 10 illustrates the heart valve replacement prosthetic 1 after the
driver 40 has
completed driving a plurality of anchors 50 about the periphery of ring 10,
and further after
the applicator 20, including applicator shaft 21 and spring arms 22, have been
withdrawn. To
withdraw the applicator 20, the applicator shaft 21 may be moved in a distal
direction,
extending spring arms 22 further beyond the distal side of the ring 10, and
permitting the
conical structure formed by the spring arms 22 to collapse. Once collapsed,
the spring arms
22 may be permitted to pass through ring 10 with the withdrawal of the
applicator shaft 21, so
that the entire applicator 20 may be withdrawn from the implant site.
Anchors 50 may be any of the anchors described in U.S. Patent Provisional
Application No. 61/296,868, filed January 20, 2010, U.S. Patent Application
Serial No.
13/010,766, filed January 20, 2011, U.S. Patent Application Serial No.
13/828,256, filed
March 14, 2013, U.S. Patent Application Serial No. 13/843,930, filed March 15,
2013, and
U.S. Patent Application Serial No. 14/301,106, filed June 10, 2014, each of
which is
incorporated by reference in their entirety as if fully disclosed herein.
For example, Figure 11 shows an anchor or implant 200 which is configured to
be
driven into a tissue. The anchor 200 includes a corrugated body 201. The body
201 includes
grooves 203 that extend axially along the length of the body 201. Thus,
extending
circumferentially around the body 201, a plurality of grooves 203 alternate
with a plurality of
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ridges 205. Further, the anchor body 201 includes a pair of wings or split
portio
208. The split portions 207 and 208 are formed by respective splits or cuts
209 into the body
201. In this regard, the splits 209 may be formed by making a cut radially
into the body 201
and extending in an axial direction. Thus, the two split portions 207 and 208
are attached to
the remainder of the body 201 at a distal position and extend proximally to
free ends. The
free ends include a plurality of sharp protrusions along a curved surface.
These points are
formed due to the corrugations. In particular, the ridges 205 form the sharp
protrusions, as
illustrated in the inset partial side view in Figure 11, which are
advantageous for gripping
tissue and preventing distal sliding of the anchor 200. Although each split
portion 207 and
208 includes three such protrusions as illustrated, it should be understood
that the anchor 200
may be designed such that one or more of the split portions has any other
number of
protrusions, including a single sharp protrusion. For example, if a larger
number of sharp
protrusions are desired, the body 201 could be more densely corrugated (i.e.,
a greater
number of alternating grooves 203 and ridges 205 could be provided) and/or the
angle of the
cut or slice could be adjusted. Further, the length of proximal extension of
the projections
may be adjusted by varying the depth of the grooves 203 with respect to the
ridges 205.
The split portions 207 and 208 do not substantially impede distal insertion
into tissue
but resist proximal movement from an insertion location by engaging the
tissue. It has been
discovered that the combination of the pointed and/or sharp-edged proximal
ends of the split
portions 207 and 208 with the alternating ridges on the proximal end of the
split portions
creates improved performance.
Further, the split portions or wings 207 and 208 are axially offset from each
other.
For example, split 207 is axially located at position along axis xx and split
208 is axially
located at position b along axis xx. This allows for greater structural
strength of the other
portions of the body 201 as compared to a non-offset configuration. In
particular, since the
cuts progress continually radially inward as they progress distally, a non-
offset portion would
have a substantially smaller amount of material in cross-section at the distal
end of the cut.
This would lead to a mechanically weak point or region along the axis of the
body and could
lead to mechanical failure, especially in anchors of small dimensions.
Although the anchors
200 utilize a pair of wings 207 and 208 to anchor the anchors 200 against
proximal retraction
from a tissue, it should be appreciated that any number of wings may be
provided, and that as
an alternative or in addition to the wings 207 and 208, any other appropriate
anchoring
structure(s), e.g., anchoring filaments, may be provided.
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The distal tip of the anchor 200 is pyramidal, with a sharp point, and a pl
surfaces separated by edges that converge at the sharp point. Although four
planar surfaces
are provided, it should be appreciated that any appropriate suitable number of
surfaces may
be provided and that one or more or all of the surfaces may be non-planar.
The anchor 200 may include one or more shoulders, formed by the junction of a
wing
207, 208, with the body 201, or otherwise defined by the area of the anchor
200 where the
wing 207, 208, extends proximally and radially outwardly from the distal end,
or distal
thereto. As illustrated in Figure 11, wings 207, 208, have a relaxed,
uncompressed position,
but may be compressed to a second, compressed position, in closer
approximation with the
body 201. Further, the body 201 may be flexible, such that forces experienced
in the
proximal end may influence the position of the body or stem 201 with respect
to the wings
207, 208, and the distal end.
The anchor 200 may be produced by first forming the body 201 with the
corrugations,
e.g., by injection molding or extrusion, and subsequently forming split
portions 207 and 208,
e.g., by cutting radially into the side of the body 201. As illustrated, the
cut is curved, with
an angle (at the proximal entry point), relative to the longitudinal axis xx
of the body 201,
that gradually decreases from the proximal initial cutting location toward the
distal end of the
anchor 200 and eventually becoming linear. Although the split or cut of the
illustrated
example is made with a curved or varying angle with respect to the
longitudinal axis xx of the
body 201, it should be understood that any appropriate cut, including a linear
cut, may be
made.
Although the anchor 200 includes two wings or split portions spaced equally
around
the radial periphery of the body 201, it should be appreciated that any number
of split
portions, including a single split portion may be provided and at any
appropriate spacing
around the radial periphery of the anchor 200.
Modern manufacturing processes allow for near nano technology applications.
This
allows the anchors to be manufactured in a size and complexity that may not
have been
possible in years past. The anchor 200 may be injection molded of either
absorbable or non-
absorbable polymers and then processed (e.g., by cutting) to add the features
of the wings 207
and 208. Although the anchors 200 are formed of polymer, it should be
appreciated that any
appropriate material may be used, e.g., metal or a composite material. The
anchors 200 may
have a diameter of, e.g., one millimeter, or approximately one millimeter, and
a length that is
in a range from, e.g., 5 millimeters to 10 millimeters. According to some
example
embodiments, the diameter is less than one millimeter. According to some
example
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embodiments, the diameter is in a range from 0.8 millimeters to 1.2
millimeters.
understood, however, that other dimensions may be provided.
In an exemplary embodiment of the present invention, the anchor 4200
illustrated in
Figure 12 is described. Anchor 4200 includes a distal tip 4230, and a stem
4201 extending
proximally from the base of distal tip 4230. Stem 4201 joins the base of
distal tip 4230 at
shoulder 4240. Wings or barbs 4207, 4208 extend proximally, and, to some
degree, radially,
from the base of distal tip 4230, and join the base of distal tip 4230 at
shoulder 4240. Barbs
4207, 4208 extend proximally and radially from the distal tip 4230 to free
ends. The free
ends may flare further radially outward, as illustrated in Figure 12. Unlike
the wings or split
portions 207, 208 described above, wings or barbs 4207, 4208 are not formed
from cuts or
splits to the body of the anchor, so that the thickness of stem 4201 may be
unaffected by the
inclusion of barbs 4207, 4208. Wings or barbs 4207, 4208 may have a relaxed,
uncompressed position, illustrated in Figure 12. In the uncompressed position,
barbs 4207,
4208 are unbiased, having a barb opening W. Barbs 4207, 4208 may be compressed
into
closer approximation with stem 4201. Varying amounts of compression may be
applied to
the barbs, such that the greater the compression, the closer approximation of
the barbs to the
stem. Barbs 4207, 4208 may include protrusions at the free ends of the barbs,
to engage with
tissue once the anchor has been deployed. While two barbs 4207, 4208 are
illustrated, it
should be appreciated that any number of barbs may be provided. Similarly, any
number of
protrusions at the free ends of the barbs may be provided, including one sharp
protrusion.
Stem 4201 may be flexible, able to be bent or flexed with respect to barbs
4207, 4208
and distal tip 4230. Once deployed into tissue, a flexible stem provides for a
different profile
of forces acting on the anchor 4200, as compared to an anchor having a rigid
or stiff stem. A
flexible shaft, able to flex in relation to the barbs and the distal tip,
creates a living hinge
between these elements of the anchor. Forces acting on the anchor from its
proximal end
may be at least partially absorbed by the flexible stem, so that the impact of
these forces on
the wings or barbs of the anchor may be reduced. In certain tissue
environments, a flexible
shaft may be more likely to prevent a levering action by the anchor, and may
thereby prevent
the anchor from partially or even completely pulling out of the tissue.
Further, the anchors 50, 200, 4200 may include any of the features of the
fasteners or
other analogous implants disclosed in U.S. Provisional Patent Application
Serial No.
61/296,868, filed on January 20, 2010, in U.S. Patent Application Serial No.
13/010,766,
filed on January 20, 2011, and U.S. Patent Application Serial No. 14/301,106,
filed on June
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10, 2014, each of which is incorporated by reference in its entirety as if
fully dis
herein, and may be driven using any mechanism disclosed therein.
To fire the anchors, a force delivery system may be situated at the proximal
end of the
driver. The force delivery system may use any mechanisms of nearly
instantaneous force
transfer, such as springs, gas, compressed fluid, or the like. Force is
transferred through the
shaft of the driver, which may be a rigid shaft or a flexible shaft, depending
on the
application. The force is used to displace a firing mechanism at the distal
end of the shaft,
which in turn exerts a driving force on the anchors to drive the anchors from
the firing arms
and into the prosthetic valve and the surrounding tissue. The driving force
may result from a
pushing force delivery system, which directs force in the distal direction of
the driver, or a
pulling force delivery system, which directs force in the proximal direction
of the driver,
depending on the application.
In an exemplary embodiment of the present invention, a plurality of firing
arms may
be provided around the applicator, as illustrated in Figures 13 to 20. Figures
13 and 14 show
driver 60 having, at its distal end, a plurality of firing arms 61 situated
annularly around
tubular guide 63. Guide 63 may surround an applicator shaft, much like guide
43. Firing
arms 61 are in a refracted position against the driver and parallel to the
axis of the driver.
Figure 14 also shows anchors 4200 provided in the firing arms 61. Windows 64
allow for the
barbs 4207, 4208 to be stored in the firing arm 61 in their relaxed position
before being
driven from the anchor outlet and into the ring 10 and the surrounding tissue.
Figures 15 and 16 illustrate the driver 60 in which the firing arms have been
moved
from the retracted position to a firing position. The movement of the firing
arms from the
retracted position of Figures 13 and 14 to the firing position of Figures 15
and 16 may be
achieved by manual or electric actuation of a translating force, for example,
by a screw or a
sliding mechanism, or by any other mechanical operation. Firing arms 61 are
hinged to
driver 60 at the distal end of the driver, so that the firing arms 61 open
radially outwardly
from a position proximal to the hinges and the distal end of the driver 60.
The firing position
of the firing arms may be at an angle of less than 90 degrees from the axis of
driver 60. An
acute angle of firing arms 61 allows for an angled anchor delivery into ring
10 and the
surrounding tissue, and therefore greater control of the placement of the
anchors in the
surrounding tissue.
As illustrated in Figure 16, firing arms 61 include firing mechanisms 65 and
fingers
66, for driving anchors 4200 through anchor outlets 62. Guide 63 is connected
to firing
mechanisms 65 and fingers 66, so that the application of a proximal or pull
force to the guide
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will translate the force in a proximal direction to the firing mechanisms 65
and f
Fingers 66 abut shoulder 4240 of anchor 4200, and may transfer the pull force
from the guide
63 and firing mechanism 65 to anchor 4200.
Figures 17, 18, 19, and 20 illustrate the firing of anchors 4200. Anchors 4200
are
fired by exertion of a proximal or pulling force, pulling guide 63 in a
proximal direction with
respect to driver 60. As shown in Figures 17 and 18, guide 63 is drawn nearly
level with the
hinged ends of firing arms 61, and, as shown in Figures 19 and 20, guide 63 is
drawn to a
recessed position with respect to the hinged ends of firing arms 61. The
proximal force
drawing guide 63 is transferred to firing mechanisms 65, and in turn to finger
66, which then
transfers the driving force to shoulder 4240 of anchor 4200, driving anchor
4200 through
anchor outlet 62, into ring 10 and the surrounding tissue. In this manner, all
of the firing
arms 61 may fire anchors 4200 at the same time.
Further, any of the implantable elements described herein, e.g., anchors 50,
200, 4200,
and ring 10, leaflets 30, valve struts 31, or any other element of heart valve
replacement
prosthetic 1, may be formed wholly or partly of a material absorbable into the
patient's body,
or of a non-absorbable material, depending on, e.g., the specific application.
For example,
these elements may be formed of polyglycolic acid (PGA), or a PGA copolymer.
These
elements may also, or alternatively, be formed of copolymers of polyester
and/or nylon
and/or other polymer(s). Moreover, these elements may contain one or more
shape-memory
alloys, e.g., nitinol, spring-loaded steel or other alloy or material with
appropriate properties.
Absorbable materials may be advantageous where there is a potential for
misfiring or
improper locating of the various implants. For example, in a situation where
the driver drives
an anchor 50, 200, 4200 at an unintended location, or where the tissue does
not properly
receive the anchor 50, 200, 4200, the anchor 50, 200, 4200, even where not
needed, would be
relatively harmless, as it would eventually absorb into the patient's body.
Although particular example heart valve replacement prosthetic systems have
been
described above, the systems and devices described here are in no way limited
to these
examples.
Although the present invention has been described with reference to particular
examples and exemplary embodiments, it should be understood that the foregoing
description
is in no manner limiting. Moreover, the features described herein may be used
in any
combination.
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