U.S. patent application number 17/093176 was filed with the patent office on 2021-02-25 for heart valve repair devices for placement in ventricle and delivery systems for implanting heart valve repair devices.
This patent application is currently assigned to Mitralix Ltd.. The applicant listed for this patent is Mitralix Ltd.. Invention is credited to Yonatan BEN-ZVI, Ira YARON.
Application Number | 20210052385 17/093176 |
Document ID | / |
Family ID | 1000005207186 |
Filed Date | 2021-02-25 |
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United States Patent
Application |
20210052385 |
Kind Code |
A1 |
YARON; Ira ; et al. |
February 25, 2021 |
Heart Valve Repair Devices for Placement in Ventricle and Delivery
Systems for Implanting Heart Valve Repair Devices
Abstract
Devices and methods for the repair of the functioning of heart
valves are provided. A device may comprise a ventricular winding
having a generally spiral shape, wherein the device is free of any
atrial stabilizing section. A method involves positioning the
device such that chords associated with the heart valve are
positioned within the path of the generally spiral shape of the
ventricular winding and turning the ventricular winding such that
the chords move closer to the center of the ventricular winding.
The ventricular winding draws the chords closer together, thereby
pulling the valve leaflets closer together in order to facilitate
their coaptation and proper closing. A delivery system for
maneuvering and releasing a heart valve repair device comprises an
applicator tube and internal rod.
Inventors: |
YARON; Ira; (Har Adar,
IL) ; BEN-ZVI; Yonatan; (Kiryat Tiv'on, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Mitralix Ltd. |
Yokne'am Moshava |
|
IL |
|
|
Assignee: |
Mitralix Ltd.
Yokne'am Moshava
IL
|
Family ID: |
1000005207186 |
Appl. No.: |
17/093176 |
Filed: |
November 9, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16115809 |
Aug 29, 2018 |
10864079 |
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17093176 |
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15616304 |
Jun 7, 2017 |
10098738 |
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16115809 |
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14315749 |
Jun 26, 2014 |
9700412 |
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15616304 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61F 2/2466 20130101;
A61F 2/2457 20130101; A61F 2/2442 20130101; A61F 2/2445 20130101;
A61F 2230/0091 20130101 |
International
Class: |
A61F 2/24 20060101
A61F002/24 |
Claims
1. A device for assisting the functioning of a heart valve
comprising: a ventricular winding having a generally spiral shape
adapted to be positioned on a ventricular side of the heart valve
such that chords associated with the heart valve are positioned
within the path of the generally spiral shape of the ventricular
winding; wherein the device is free of any atrial stabilizing
section.
2. A device as in claim 1, wherein the ventricular winding is
substantially flat.
3. A device as in claim 1, wherein the ventricular winding is
substantially conical.
4-6. (canceled)
7. A device as in claim 1, wherein the device is comprised at least
in part of a metallic material.
8. A device as in claim 1, wherein the device is comprised at least
in part of a shape memory metal material.
9. A device as in claim 1, wherein the device is comprised at least
in part of nitinol.
10. A device as in claim 1, wherein the device is comprised at
least in part of a plastic material.
11. A device as in claim 1, wherein the device is comprised at
least in part of a composite material.
12-13. (canceled)
14. A device as in claim 1, wherein the ventricular winding has an
end portion that is angled downwardly.
15. A method of repairing a heart valve comprising: delivering a
heart valve repair device to the area of the heart valve, the heart
valve repair device comprising a ventricular winding having a
generally spiral shape; and positioning the ventricular winding on
a ventricular side of the heart valve such that chords associated
with the heart valve are positioned within the path of the
generally spiral shape of the ventricular winding; wherein the
heart valve repair device is free of any atrial stabilizing
section.
16. A method as in claim 15, wherein the step of positioning the
ventricular winding comprises turning the ventricular winding in a
first direction such that the chords move closer to the center of
the ventricular winding.
17. (canceled)
18. A method as in claim 16, wherein the step of positioning the
ventricular winding comprises, after turning the ventricular
winding in a first direction, turning the ventricular winding in a
second direction such that the chords move further from the center
of the ventricular winding, to adjust the positioning of the chords
in the device.
19. (canceled)
20. A delivery system for implanting a heart valve repair device
for repairing a heart valve comprising: an applicator tube; and an
internal rod within the applicator tube; wherein the internal rod
is adapted to hold the heart valve repair device during maneuvering
of the device; and wherein the delivery system is adapted to
release the heart valve repair device by advancement of the
internal rod relative to the applicator tube after positioning the
heart valve repair device in the desired location.
21. A system for repairing a heart valve comprising: a delivery
system comprising an applicator tube and an internal rod within the
applicator tube to deliver a heart valve repair device to an area
of the heart valve; and a heart valve repair device comprising a
ventricular winding that in an unconstrained condition has a
generally spiral shape, the heart valve repair device further
comprising a grasping element that is connected to the center of
the ventricular winding and that extends from the center of the
ventricular winding; wherein the heart valve repair device is
adapted to be advanced to the area of the heart valve with the
ventricular winding held within the applicator tube of the delivery
device in a constrained condition in which the ventricular winding
has a relatively straightened shape; wherein the ventricular
winding is adapted to be released from the applicator tube, thereby
allowing the ventricular winding to assume its unconstrained
condition in which it has the generally spiral shape; wherein the
ventricular winding is further adapted to be positioned on the
ventricular side of the heart valve and turned in a first direction
such that the ventricular winding captures chords associated with a
first leaflet of the heart valve and chords associated with a
second leaflet of the heart valve within one generally spiral path
defined by the generally spiral shape of the ventricular winding,
wherein by turning the ventricular winding in the first direction,
the captured chords of the first leaflet and the second leaflet
within the generally spiral path are brought toward the center of
the ventricular winding, thereby causing the first leaflet and the
second leaflet of the heart valve to be drawn together; wherein the
heart valve repair device is adapted to be released from the
delivery system; and wherein the heart valve repair device is free
of any atrial stabilizing section.
22. The system as in claim 21, wherein in the unconstrained
condition of the ventricular winding, the generally spiral shape
moves increasingly further away from the center of the ventricular
winding as it winds around the center of the ventricular
winding.
23. The system as in claim 21, wherein the generally spiral shape
comprises at least a first turn and a second turn, wherein in a
radial direction from a center of the ventricular winding the
second turn is farther away from the center of the ventricular
winding than the first turn, and wherein at least the first turn is
a full turn extending 360 degrees around a center of the
ventricular winding.
24. The system as in claim 21, wherein the grasping element has an
axis, and wherein the ventricular winding is adapted to be turned
by using the delivery device to turn the grasping element, whereby
turning the grasping element results in turning the ventricular
winding generally around the axis of the grasping element.
25. The system as in claim 21, wherein the heart valve repair
device is adapted such that after release from the delivery system,
the heart valve repair device does not have any part that extends
into an atrial side of the valve.
26. The system as in claim 21, wherein an overall diameter of the
ventricular winding is adapted to be smaller than a diameter of an
annulus of the heart valve.
27. The system as in claim 21, wherein the ventricular winding is
adapted to capture less than substantially all of the chords
associated with the heart valve.
Description
FIELD OF THE INVENTION
[0001] The invention relates to devices and methods for the repair
of the functioning of heart valves, in particular the mitral
valve.
BACKGROUND OF THE INVENTION
[0002] Heart valves regulate the movement of blood into and out of
the chambers of the heart. The mitral valve, positioned between the
left atrium and the left ventricle, can be subject to a condition
known as mitral regurgitation, in which the mitral valve does not
close properly and some backflow of blood occurs from the left
ventricle back into the left atrium. For example, a mitral valve
leaflet can experience prolapse during systole, thereby inhibiting
leaflet coaptation and permitting backflow of blood into the left
atrium.
[0003] Various procedures and devices have been proposed to address
the condition of mitral regurgitation. For example, some mitral
valve repair procedures involve removing a section of a valve
leaflet in order to reduce its propensity for prolapse. Other
procedures involve mitral valve replacement. The MITRACLIP (Abbott
Vascular) is a device intended to be positioned across the mitral
valve to create a double orifice, in an effort to allow the valve
to close fully during systole.
[0004] US 2010/0331971 discloses cardiac valve downsizing devices
and methods.
[0005] The objective of these downsizing devices is to downsize the
annulus of the valve by circumflexing all or substantially all of
the chords. A downsizing device as disclosed in US 2010/0331971 is
formed as a helix wherein a lower part of the helix is designed to
extend on the ventricular side of the valve along an outer
periphery adjacent the heart wall around the outermost chords. This
outer periphery is accessed by extending the helix through a
commissure at the periphery of the valve or through the annulus
itself. Rotating the helix causes advancement of the helix so that
part of the helix extends into the ventricle at the outer periphery
around the outermost chords, while part of the helix is in the
atrium, adjacent the annulus, thereby anchoring the device with
respect to the atrium.
[0006] The Applicant's prior application US 2013/0006352 also
relates to devices and methods for the repair of the functioning of
heart valves. US 2013/0006352 discloses heart valve repair devices
designed to draw the desired leaflet edge areas together. A device
as disclosed in US 2013/0006352 comprises a first section having a
generally spiral shape, with the spiral shape emanating from a
center of the spiral, and a second section connected to the first
section at the center of the first section. The first section is
positioned on the ventricular side of the heart valve, with the
selected chords positioned within the path of the generally spiral
shape, and the second section is positioned on the atrial side of
the heart valve. US 2013/0006352 discloses that, in a device as
described therein, the ventricular section draws the captured
chords together, thereby pulling the desired valve leaflet areas
together, while the atrial section stabilizes or anchors the device
relative to the atrium.
[0007] There is a continuing need for improved treatment for mitral
valve regurgitation and for the repair of the functioning of heart
valves in general. The various procedures and devices previously
proposed can be improved upon in terms of their overall clinical
outcome, ease of use, reduction of procedure time and risk, and/or
reduction of cost.
SUMMARY OF THE INVENTION
[0008] The present invention provides devices and methods for the
repair of the functioning of heart valves.
[0009] In prior heart valve repair devices for capturing leaflet
chords as exemplified in certain prior devices as discussed above,
the devices have included parts or sections for anchoring the
devices relative to the atrium, in order to ensure that the devices
remained stable in the heart once implanted. The inventive heart
valve repair devices as described herein depart from these prior
teachings. A heart valve repair device as described herein
comprises a ventricular winding for capturing leaflet chords and
drawing them together, without having any connected atrial
stabilizing section that stabilizes or anchors the device relative
to the atrium. The device, without any atrial stabilizing section,
has freedom to move with respect to the atrium, providing
previously unrecognized advantages as described below that could
not be attained by prior devices that were anchored to the atrium.
While prior devices as discussed above have included atrial
anchoring in order to ensure stability after implantation, the
inventors have found, in both ex vivo testing and in vivo animal
testing, that a device as described herein with a ventricular
winding and without a connected atrial stabilizing section is
sufficiently held in place by the interaction between the
ventricular winding and the chords, thereby allowing the device to
be practiced without a connected atrial stabilizing section,
realizing advantages as described herein.
[0010] In some embodiments, the implantable heart valve repair
device comprises, consists essentially of, or consists of a
ventricular winding having a generally spiral shape adapted to be
positioned on a ventricular side of the heart valve such that
chords associated with the heart valve are positioned within the
path of the generally spiral shape of the ventricular winding. The
ventricular winding is designed to draw chords associated with the
heart valve closer together, thereby pulling the valve leaflets
closer together in order to facilitate their coaptation and proper
closing. The implantable heart valve repair device in these
embodiments is "free of any atrial stabilizing section," meaning
that the device does not have any part that is adapted to stabilize
the device by engaging tissue on the atrial side of the valve, such
as the wall of the atrium or the annulus of the valve on the atrial
side.
[0011] In some embodiments, the implantable heart valve repair
device has a stabilizing section that consists only of a
ventricular stabilizing section that is adapted to engage tissue
only on the ventricular side of the valve. The ventricular
stabilizing section may consist essentially of, or consist only of,
or may be in the form of a ventricular winding having a generally
spiral shape as described above for drawing chords associated with
the heart valve together. The ventricular winding is adapted to
engage tissue only on the ventricular side of the valve, and the
ventricular winding stabilizes the device by the interaction
between the ventricular winding and the chords on the ventricular
side of the valve.
[0012] In some embodiments, the implantable heart valve repair
device may include a grasping element for facilitating grasping and
maneuvering the device during implantation. In some embodiments,
the implantable heart valve repair device may include an end
portion that is bent downwardly from the general plane of the
ventricular winding. In some embodiments, the implantable heart
valve repair device may include one or more anti-rotation elements
for resisting a backwards rotation of the ventricular winding.
[0013] In some embodiments of a method of repairing a heart valve,
a heart valve repair device is delivered to the area of the heart
valve, wherein the device comprises, consists essentially of, or
consists of a ventricular winding having a generally spiral
shape.
[0014] The method further includes positioning the ventricular
winding on a ventricular side of the heart valve such that chords
associated with the heart valve are positioned within the path of
the generally spiral shape of the ventricular winding. The step of
positioning the ventricular winding may further include turning the
ventricular winding in a first direction such that the chords move
closer to the center of the ventricular winding. This movement of
the chords pulls the valve leaflets closer together in order to
facilitate their coaptation and proper closing. The method may be
practiced with a heart valve repair device that is free of any
atrial stabilizing section, as described above.
[0015] In some embodiments of a delivery system for implanting a
heart valve repair device, the delivery system comprises an
applicator tube and an internal rod within the applicator tube. The
internal rod may be adapted to hold the heart valve repair device
during maneuvering of the device. The delivery system is adapted to
release the heart valve repair device after positioning of the
heart valve repair device in the desired location. The delivery
system may include a window through which all or part of the heart
valve repair device may be ejected. The delivery system may also
include a ramp surface for facilitating ejection of the heart valve
repair device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 shows a perspective view of an embodiment of a heart
valve repair device.
[0017] FIG. 2 shows a side view of another embodiment of a heart
valve repair device.
[0018] FIG. 3 shows a side view of another embodiment of a heart
valve repair device.
[0019] FIG. 4 shows a top view of another embodiment of a heart
valve repair device.
[0020] FIGS. 5A-5C show alternative versions of heart valve repair
devices with anti-rotation elements.
[0021] FIG. 6 illustrates a proximal end of a delivery system for
implanting a heart valve repair device.
[0022] FIG. 7A shows a top view of a distal end of the delivery
system of FIG. 6.
[0023] FIG. 7B shows a side view of a distal end of the delivery
system of FIG. 6.
[0024] FIG. 8 shows a perspective view of the distal end of the
delivery system of FIG. 6 with a heart valve repair device being
held by the delivery system.
[0025] FIG. 9 shows a perspective view of the distal end of the
delivery system of FIG. 6 with a heart valve repair device being
ejected from the delivery system.
[0026] FIG. 10 shows a retention wire threaded through a grasping
element of a heart valve repair device.
[0027] FIG. 11 shows another embodiment of a delivery system hook
and grasping element.
[0028] FIG. 12 shows a top view diagram of leaflets of a mitral
valve.
DETAILED DESCRIPTION
[0029] The Applicant's prior application US 2013/0006352 discloses
various heart valve repair devices and methods of implanting them.
The disclosure of US 2013/0006352 is hereby expressly incorporated
herein by reference.
[0030] Certain embodiments of heart valve repair devices and
methods of using them are described herein with reference to the
accompanying drawings. These embodiments are only examples, as
numerous variations of the invention disclosed herein are possible
within the scope of the appended claims.
[0031] FIG. 1 shows a first embodiment of a heart valve assisting
device 110. The device 110 comprises a ventricular winding 112 and
a grasping element 120. As described below, the ventricular winding
112 serves the functions of both facilitating valve leaflet
coaptation and stabilizing or anchoring the device with respect to
the chords.
[0032] The term "spiral" is used herein to refer broadly to shapes
defined by a structure forming a winding around a center wherein
the winding gradually moves away from the center as it winds around
the center. The structure of the winding may begin or emanate from
an area at or near the center of the winding. The winding may move
away from the center at a constant rate or at a non-constant rate,
and the general outline of the spiral may take various shapes, such
as substantially circular, substantially elliptical, or other
shapes. The spiral may be symmetrical or asymmetrical, and the
center around which the winding structure winds may be a point at
the geometric center of the spiral or a point that is offset from
the geometric center of the spiral. The winding may be in one
plane, such that the spiral is substantially flat. Alternatively,
the winding may not be in one plane, with the winding moving up or
down at a constant or non-constant rate. Thus, for example, the
spiral may be substantially conical. The winding may make multiple
turns around the center or less than a full turn around the center.
The winding structure of the spiral forms a path that starts from
an opening at the outer periphery of the spiral and that moves
toward the center of the spiral as the path winds around the center
of the spiral.
[0033] As can be seen in FIG. 1, the ventricular winding 112 has a
generally spiral shape. The spiral shape is defined by the wire
structure of the ventricular winding 112 forming a winding around a
center 114 of the ventricular winding 112, wherein the wire
structure of the winding begins or emanates from an area at or near
the center 114 and gradually moves away from the center 114 as it
winds around the center 114. In the case of FIG. 1, the winding of
the ventricular winding 112 moves away from the center 114 at a
generally constant rate, and the general outline of the spiral of
the ventricular winding 112 has a substantially circular shape.
[0034] In the embodiment of FIG. 1, the ventricular winding 112 is
generally in one plane, with an end portion 124 of the ventricular
winding 112 being bent or angled downwardly as shown. In an
alternative embodiment, the ventricular winding 112 may move
gradually out of plane.
[0035] As shown in FIG. 1, the winding structure of the ventricular
winding 112 forms a path 118 that starts from an opening 116 at the
outer periphery of the spiral and that moves toward the center 114
of the spiral as the path 118 winds around the center 114 of the
spiral. In this illustrated embodiment, the path 118 comprises
about three turns around the center 114. More or fewer turns may be
used.
[0036] As described above, the spiral may take other shapes. In
addition, the ventricular winding may be comprised of more than one
spiral. For example, the ventricular winding may have two, three,
four, or more spirals, which may be similar or dissimilar to each
other. In one example, two spirals may emanate from a common
center, each being similar to the other except that each starts in
a direction that is 180 degrees from the other. This example
results in nested spirals in which the opening of each of the
spirals is 180 degrees from the opening of the other spiral. In
other examples, three spirals may emanate from a common center,
starting 120 degrees apart and having openings 120 degrees apart,
or four spirals may emanate from a common center, starting 90
degrees apart and having openings 90 degrees apart.
[0037] The overall diameter D1 of the ventricular winding may be
substantially smaller than the diameter of the annulus of the
valve. This enables maneuvering the ventricular winding to capture
only selected groups of chords, in order to pull together desired
areas of the valve leaflets. For example, the overall diameter D1
of the ventricular winding 112 may be approximately 1.0-2.0
centimeters (e.g., 1.2, 1.5, or 1.8 centimeters), but larger or
smaller diameters are possible.
[0038] At its outer end, the ventricular winding 112 terminates at
the end portion 124. In the embodiment of FIG. 1, the end portion
124 is bent downwardly from the general plane of the ventricular
winding 112. The end portion 124 is formed as a loop of the wire
structure of the ventricular winding 112, connected at junction
126. In this manner, the end portion 124 terminates at a rounded
atraumatic tip 125.
[0039] In this embodiment, the length of the end portion 124 is
approximately 5 mm, and it may have other lengths, such as 8 mm, or
longer or shorter lengths. The end portion 124 in this embodiment
bends downwardly from the general plane of the ventricular winding
112 by an angle of approximately 15 degrees, and it may bend at
other angles, such as 25 degrees, or larger or smaller angles. In
this embodiment, the design results in a gap in the axial direction
between the general plane of the ventricular winding 112 and the
tip 125 of the end portion 124 of approximately 1 mm to 5 mm, but
larger or smaller gaps are possible.
[0040] The grasping element 120 is connected to the center 114 of
the ventricular winding 112 and extends upwardly from the center
114 of the ventricular winding 112.
[0041] As shown in FIG. 1, the grasping element 120 is formed of a
continuation of the wire structure of the ventricular winding 112.
The wire structure forming the grasping element 120 extends
upwardly from the general plane of the ventricular winding 112 at
an angle of approximately 90 degrees, although other angles may be
used. After extending upwardly from the ventricular winding 112,
the wire structure of the grasping element 120 bends at a top bend
121 and extends downwardly to an end 122 of the wire structure,
thereby forming a loop. The top bend 121 forms an atraumatic tip,
and the end 122 may be blunt or rounded or may form a junction with
the adjacent portion of the wire structure, similar to the junction
126. In alternative embodiments, the grasping element 120 may be
substantially straight, curved, bent, helical, or any other
suitable shape. In one example, the length of the grasping element
120 (from the connection with the ventricular winding 112 to its
top at bend 121) may be approximately 5 mm to 20 mm, for example 6
mm to 8 mm or 10 mm, but longer or shorter lengths are
possible.
[0042] As can be seen in FIG. 1, the implantable heart valve repair
device 110 is free of any atrial stabilizing section, i.e., the
device does not have any part that is adapted to stabilize the
device by engaging tissue on the atrial side of the valve, such as
the wall of the atrium or the annulus of the valve on the atrial
side. It is possible, for example, that after implantation the
grasping element 120 extends through the valve to the atrial side,
and it may contact the leaflets as they close. However, neither the
grasping element 120 nor any other part of the device 110 is
adapted to engage tissue on the atrial side of the valve in a
manner that stabilizes or anchors the device with respect to the
atrium.
[0043] The device 110, including the ventricular winding 112 and
the grasping element 120, is comprised of a wire. In alternative
embodiments, all or part of the device may comprise a wire, a
bundle of wires, a strip, a rod, or a tube, and different sections
of the device or parts thereof may comprise a wire, a bundle of
wires, a strip, a rod, a tube, or a combination thereof. The
structure may be formed by bending or otherwise shaping a wire, a
bundle of wires, a strip, a rod, or a tube into the desired shape.
The desired shape may be obtained by "baking" the material in a
certain shape at a certain temperature such that the material will
remember that shape. Alternatively, the shape may be formed as the
wire, bundle of wires, strip, rod, or tube is formed. For example,
the spiral shape of the ventricular winding may be chemically or
laser etched or otherwise cut from a sheet of material, in which
case the strip or rod is formed simultaneously with the spiral
shape. The device may be formed of more than a single structure or
material; for example, a tube with a wire core may form the
ventricular winding and/or the grasping element, with the other
element formed of a similar or dissimilar structural component.
[0044] The use of a bundle of wires can provide the device with
high axial strength as well as high flexibility. For example, the
use of several thin wires in a twisted bundle or in a braided
bundle provides high axial strength and flexibility that can be
determined by the twisting or braiding structure.
[0045] The wire, bundle of wires, strip, rod or tube may have any
suitable cross-sectional shape. For example, the wire, bundle of
wires, strip, rod or tube may have a circular, elliptical, square,
rectangular, hexagonal, or other cross-sectional shape. The wire,
bundle of wires, strip, rod, or tube may have different
cross-sectional shapes or sizes at different places along its
length. The wire of device 110 has a circular cross-sectional shape
along its length. In one example, the wire, bundle of wires, strip,
rod, or tube may have a diameter, width or thickness of
approximately 0.2-1.0 millimeters (e.g., 0.4 millimeters), but
larger or smaller dimensions are possible.
[0046] The wire of device 110 is formed from a suitable shape
memory metal, for example nitinol. Other suitable materials may be
used for all or part of the wire(s), rod(s), or tube(s) of the
device, for example other shape memory materials, other metallic
materials, plastic materials and/or composite materials.
[0047] The device 110 of FIG. 1 has rounded ends 121, 125 at the
ends of the grasping element 120 and end portion 124. In
alternative embodiments, one or more ends of the wire, bundle of
wires, strip, rod, or tube may be rounded, squared-off, or pointed.
As described further below, the device may have one or more
anti-rotation elements.
[0048] As can be seen in FIG. 1, the spiral of ventricular winding
112 can be considered as being wound in a clockwise direction when
viewed from the top and starting from the center and moving
outward. In an alternative embodiment, the spiral of the
ventricular winding 112 can be wound in an opposite direction.
[0049] The wire, bundle of wires, strip, rod, or tube may have one
or more grooves in its outer surface. The groove in the outer
surface of the wire, bundle of wires, strip, rod, or tube may
extend around the perimeter of the wire, bundle of wires, strip,
rod, or tube and/or in the direction of the length of the wire,
bundle of wires, strip, rod, or tube. As one example, the wire,
bundle of wires, strip, rod, or tube may have one more grooves that
extend in a substantially helical path along the wire, bundle of
wires, strip, rod, or tube. Such grooves may serve different
purposes. For example, one or more grooves may be used to create
different flexibilities at different places of the device, to
facilitate ingrowth of tissue, to facilitate grasping and
manipulation (e.g., pushing, pulling, turning, etc.) of the device,
and/or as channels for drug delivery. For example, a helical groove
can be used to facilitate rotation of the device as it is being
delivered from or withdrawn into a delivery catheter. Similarly, a
helical or other groove can direct cell growth in layers in a
preferred direction, thereby reducing scar formation.
[0050] The wire, bundle of wires, strip, rod, or tube may have one
or more holes in it. The holes may be through-holes extending all
the way through the thickness of the wire, bundle of wires, strip,
rod, or tube, and/or the holes may be pockets or dimples in the
outer surface of the wire, bundle of wires, strip, rod, or tube.
The holes may be a series of holes extending along the length and
around the periphery of the wire, bundle of wires, strip, rod, or
tube. The holes may serve different purposes. For example, one or
more holes may be used to create different flexibilities at
different places of the device, to facilitate ingrowth of tissue,
to facilitate grasping and manipulation of the device, to provide
ports for injection of a contrast agent, and/or as sites for drug
delivery.
[0051] The device may comprise a coating on the wire, bundle of
wires, strip, rod, or tube. The coating is preferably a
biocompatible coating that may be used, for example, to reduce
possible negative reactions from the tissue where the device is
implanted, to reduce friction (as a lubricious coating) to assist
in delivery of the device, to reduce friction in areas where the
device is designed to be moved against tissue (for example, along
the path of the spiral of the ventricular winding), to increase
friction in areas where it is desired to reduce movement or to
anchor the device, to deliver a suitable drug, for radiopacity, to
encourage cell and tissue growth that would assist in fixation
(e.g., of the upper section), to encourage tissue growth between
the chords and/or leaflets, and/or for other purposes. With respect
to radiopacity, the entire device or selected points on the device
may be coated or plated with a material allowing the physician to
understand the location of the device during and/or after the
implantation procedure. For example, the ends of the spiral may be
plated with a radiopaque material. If selected points on the device
are plated, the plating at the selected points may have a certain
shape (e.g., a line, arrow, etc.) to assist in understanding the
orientation of the device. In another example, in the case of a
device formed of a tube, the tube may be coated to ensure that the
coated tube is sealed in order that the tube may be used, for
example, for pressure measurement. When the coating is a
drug-release coating, the coating may comprise a carrier (for
example, a polymer) with the drug in the carrier for drug elution
over a suitable period of time. The drug eluting mechanism may use
a biodegradable carrier (e.g., a biodegradable polymer) or a stable
carrier (e.g., a stable polymer) that allows the drug elution
through diffusion of drug molecules.
[0052] FIG. 2 shows another embodiment of a heart valve repair
device 130. The device 130 comprises a ventricular winding 132 and
a grasping element 140. The ventricular winding 132 has a generally
spiral shape, defined by the wire structure of the ventricular
winding 132 forming a winding around a center 134 of the
ventricular winding 132. The wire structure of the winding emanates
from the center 134 and gradually moves away from the center 134 as
it winds around the center 134. In the case of device 130, the
winding of the ventricular winding 132 moves outward from the
center 134 at a generally constant rate, thereby forming a
substantially circular shape (in top view), while at the same time
the winding moves upward from its starting point at the center 134,
thereby forming a substantially conical helix opening upward, with
the base of the cone above the vertex. In an alternative
embodiment, the winding of the ventricular winding moves outward
from its starting point at the center while at the same time moving
downward from its starting point at the center, thereby forming a
substantially conical helix opening downward, with the base of the
cone below the vertex. As shown in FIG. 2, the ventricular winding
132 terminates at its outer periphery at an atraumatic end portion
144, which is bent downwardly, similar to end portion 124.
[0053] In the device 130, like the device 110, the winding
structure of the ventricular winding 132 forms a path that starts
from an opening at the outer periphery of the spiral and that moves
toward the center 134 of the spiral as the path winds around the
center 134 of the spiral.
[0054] The device 130, like the device 110, may be comprised of a
wire having a circular cross-section. The wire of device 130 may be
formed of a suitable shape memory metal, for example nitinol.
[0055] The grasping element 140 of device 130 is similar in
construction to the grasping element 120 of device 110. As can be
seen in FIG. 2, the device 130 is free of any atrial stabilizing
section.
[0056] As would be understood by persons of ordinary skill in the
art from the above descriptions, alternative embodiments of the
device 130 may be formed, using the variations described above with
respect to the device 110. Thus, for example, the ventricular
winding 132 and the grasping element 140 may comprise other forms,
shapes, sizes and/or materials as described above with respect to
the device 110. The ends of the device may be rounded, squared-off,
or pointed. The device 130 may have one or more anti-rotation
elements, as described further below. The ventricular winding 132
and/or the grasping element 140 may have one or more grooves and/or
holes, as described above. The device may comprise a coating, as
described above.
[0057] FIG. 3 shows another embodiment of a heart valve repair
device 150. The device 150 comprises a ventricular winding 152 and
a grasping element 160. The ventricular winding 152 has a generally
spiral shape, defined by the wire structure of the ventricular
winding 152 forming a winding around a center 154 of the
ventricular winding 152. The wire structure of the winding emanates
from the center 154 and gradually moves away from the center 154 as
it winds around the center 154. In the case of device 150, in an
inner section 151, the winding of the ventricular winding 152 moves
outward from the center 154 at a generally constant rate, thereby
forming a substantially circular shape (in top view), while at the
same time the winding moves upward from its starting point at the
center 154, thereby forming a substantially conical helix opening
upward, with the base of the cone above the vertex. Then, the inner
section 151 transitions to an outer section 153, in which the
winding of the ventricular winding 152 stays substantially in a
single plane as it moves outward from the center 154 at a generally
constant rate. In an alternative embodiment, the inner section may
stay substantially in a single plane with the outer section forming
a section of a substantially conical helix. As shown in FIG. 3, the
ventricular winding 152 terminates at its outer periphery at an
atraumatic end portion 164, which is bent downwardly, similar to
end portion 124.
[0058] In the device 150, like the device 110, the winding
structure of the ventricular winding 152 forms a path that starts
from an opening at the outer periphery of the spiral and that moves
toward the center 154 of the spiral as the path winds around the
center 154 of the spiral.
[0059] The device 150, like the device 110, may be comprised of a
wire having a circular cross-section. The wire of device 150 may be
formed of a suitable shape memory metal, for example nitinol.
[0060] The grasping element 160 of device 150 is similar in
construction to the grasping element 120 of device 110. As can be
seen in FIG. 3, the device 150 is free of any atrial stabilizing
section.
[0061] As would be understood by persons of ordinary skill in the
art from the above descriptions, alternative embodiments of the
device 150 may be formed, using the variations described above with
respect to the device 110. Thus, for example, the ventricular
winding 152 and the grasping element 160 may comprise other forms,
shapes, sizes and/or materials as described above with respect to
the device 110. The ends of the device may be rounded, squared-off,
or pointed. The device 150 may have one or more anti-rotation
elements, as described further below. The ventricular winding 152
and/or the grasping element 160 may have one or more grooves and/or
holes, as described above. The device may comprise a coating, as
described above.
[0062] FIG. 4 shows another embodiment of a heart valve repair
device 170. The device 170 comprises a ventricular winding 172 and
a grasping element 180. The ventricular winding 172 has a generally
spiral shape, defined by the wire structure of the ventricular
winding 172 forming a winding around a center 174 of the
ventricular winding 172. The wire structure of the winding emanates
from the center 174 and gradually moves away from the center 174 as
it winds around the center 174. In the case of device 170, the
winding of the ventricular winding 172 moves outward from the
center 174 at an uneven rate. Thus, the gap between adjacent turns
of the winding is non-constant, as can be seen by a comparison
between smaller inner gap 172A and larger outer gap 172B. As shown
in FIG. 4, the ventricular winding 172 terminates at its outer
periphery at an atraumatic end portion 184.
[0063] In the device 170, like the device 110, the winding
structure of the ventricular winding 172 forms a path that starts
from an opening at the outer periphery of the spiral and that moves
toward the center 174 of the spiral as the path winds around the
center 174 of the spiral.
[0064] The device 170, like the device 110, may be comprised of a
wire having a circular cross-section. The wire of device 170 may be
formed of a suitable shape memory metal, for example nitinol.
[0065] The grasping element 180 of device 170 may be similar in
construction to the grasping element 120 of device 110 or may be
generally in the same plane as the ventricular winding 172. As can
be seen in FIG. 4, the device 170 is free of any atrial stabilizing
section.
[0066] As would be understood by persons of ordinary skill in the
art from the above descriptions, alternative embodiments of the
device 170 may be formed, using the variations described above with
respect to the device 110. Thus, for example, the ventricular
winding 172 and the grasping element 180 may comprise other forms,
shapes, sizes and/or materials as described above with respect to
the device 110. The ends of the device may be rounded, squared-off,
or pointed. The device 170 may have one or more anti-rotation
elements, as described further below. The ventricular winding 172
and/or the grasping element 180 may have one or more grooves and/or
holes, as described above. The device may comprise a coating, as
described above.
[0067] As mentioned above, the implantable heart valve repair
devices 130, 150, and 170, like the heart valve repair device 110
and other heart valve repair devices described herein, are free of
any atrial stabilizing section. Each of the implantable heart valve
repair devices 110, 130, 150, and 170 has a stabilizing section
that consists only of a ventricular stabilizing section in the form
of a ventricular winding 112, 132, 152, and 172, which is adapted
to engage tissue only on the ventricular side of the valve and to
stabilize the device by the interaction between the ventricular
winding 112, 132, 152, and 172 and the chords on the ventricular
side of the valve. In some embodiments, these heart valve repair
devices also may be described as not having any part that, after
implantation, contacts tissue in the atrium or on the atrial side
of the valve and/or not having any part that, after implantation,
extends into the atrium or on the atrial side of the valve.
However, as described above, it is possible in some embodiments for
the grasping element to extend through the valve to the atrial
side, and it may contact the leaflets. However, these embodiments
may be constructed such that neither the grasping element nor any
other part of the device is adapted to engage tissue on the atrial
side of the valve in a manner that stabilizes or anchors the device
with respect to the atrium.
[0068] FIGS. 5A-5C illustrate examples of anti-rotation elements
that may be used with a heart valve repair device, including any of
the heart valve repair devices described herein. FIG. 5A shows a
heart valve repair device 190 having an anti-rotation element 191
in the form of a protrusion on the end of the ventricular winding.
FIG. 5B shows a heart valve repair device 192 having an
anti-rotation element 193 in the form of an enlarged tooth on the
end of the ventricular winding. FIG. 5C shows a heart valve repair
device 194 having an anti-rotation element 195 in the form of an
enlarged area on an inner turn of the winding, coming close to or
touching an adjacent turn. The anti-rotation elements can help
prevent backward rotation of the device after implantation, by
allowing easier rotation of the device in the direction of bringing
the chords together than in the opposite direction. Thus, for
example, a tooth having a slanted front face (on the side facing
the outer opening of the path of the spiral) and steep back face
can permit rotation of the device in the direction that brings the
leaflets together (by the chords passing over the slanted front
face) and can help resist rotation in the opposite direction (by
the chords acting against steep back face, thereby resisting
backward rotation).
[0069] In the example of one or more protrusions 191 as shown in
FIG. 5A, the force applied by the delivery system during the
process of turning the device 190 to capture the chords can result
in the wire structure flexing sufficiently to create a large enough
gap between the protrusion 191 and the adjacent turn of the winding
in order to allow the chords to pass therethrough, so that the
device 190 may be wound around the chords. Similarly, in the
example of one or more protrusions 193 as shown in FIG. 5B, the
force applied by the delivery system during the process of turning
the device 192 to capture the chords can result in the wire
structure flexing sufficiently to create a large enough gap between
the tooth 193 and the adjacent turn of the winding in order to
allow the chords to pass therethrough, so that the device 192 may
be wound around the chords. Similarly, in the example of one or
more enlarged areas 195 as shown in FIG. 5C, the force applied by
the delivery system during the process of turning the device 194 to
capture the chords can result in the wire structure flexing
sufficiently to create a large enough gap between the enlarged area
195 and the adjacent turn of the winding in order to allow the
chords to pass therethrough, so that the device 194 may be wound
around the chords. In each of these examples, the geometry of the
anti-rotation element(s) helps prevent the device from
unintentionally rotating in the opposite direction.
[0070] FIG. 6 illustrates a proximal end of a delivery system of a
type that may be used for implanting a heart valve repair device,
such as any of the heart valve repair devices described herein. The
delivery system 300 includes a flexible applicator 400, which is
generally tubular in shape, and an internal rod 450, which is
moveable within the applicator 400. An applicator gripper 310 may
be used to help push, withdraw, and rotate the applicator 400, in
both clockwise and counterclockwise directions. An applicator
irrigation port 320 allows injecting irrigation fluids into the
applicator 400. An internal rod torquer 330 may be used to rotate
the internal rod 450 within the applicator 400. An internal rod
grip 340 is connected to the internal rod 450 and may be used to
control movements of the internal rod 450, including pushing it
forward in order to eject a hook that is connected to internal rod
450, as described below. A scale or ruler 350 facilitates measuring
how far the internal rod 450 has been advanced, so as to determine
the position of the hook inside the applicator 400. A safety plate
360 prevents inadvertent advancement of the internal rod grip 340,
in order to eliminate the possibility of accidentally pushing the
hook outside of the applicator 400.
[0071] FIGS. 7A and 7B show top and side views, respectively, of a
distal end of the delivery system 300, with a heart valve repair
device 110 loaded on the delivery system 300. In these figures, it
can be seen that the flexible applicator 400 has lateral slots 402
to facilitate bending. Other manners of imparting flexibility to a
catheter may be used, including selection of appropriate flexible
material(s). The applicator 400 has a rounded, atraumatic distal
end 404. The applicator 400 has a window 410 through which all or
part of the heart valve repair device may be ejected. A ramp
surface 420 adjacent the distal end of the window 410 facilitates
ejection of the device, as described below.
[0072] The internal rod 450 terminates in a hook 460. The hook 460
is designed to hold the grasping element of the heart valve repair
device while the hook 460 is inside the applicator 400, proximal to
the window 410.
[0073] In a first example implantation, the delivery system 300
holds a heart valve repair device 110 as shown in FIGS. 7A and 7B,
with the ventricular winding 112 positioned outside of the lumen of
the applicator 400 and with the grasping element 120 positioned
inside the lumen of the applicator 400 and held by the hook 460. In
this position, the internal wall of the lumen of the applicator 400
prevents the grasping element 120 from exiting the hook 460. Thus,
as long as the hook 460 is inside the lumen of the applicator 400
(and not in the window 410), the grasping element 120 remains
hooked on the internal rod 450 and is thereby locked to the
internal rod 450.
[0074] The delivery system 300 is used in conjunction with a
catheter tube, for example a steerable catheter as is known in the
art. One example of a steerable catheter is the AGILIS catheter of
St. Jude Medical, Inc. The catheter is sized to accommodate the
applicator 400 of the delivery system 300. For example, if the
applicator 400 has a size of 7.5 French, the outer catheter may
have a size of 12 French. This is just an example, as other sizes
may be used.
[0075] In this first example, with the ventricular winding 112
positioned outside of the lumen of the applicator 400, the distal
end of the applicator 400 is advanced into the proximal end of the
steerable catheter. Because the lumen of the steerable catheter is
only slightly larger than the outer diameter of the applicator 400,
and smaller than the outer periphery of the ventricular winding
112, as the applicator 400 is further advanced into the catheter,
an internal turn of the ventricular winding 112 comes into contact
with the edge of the catheter tube at its proximal end. Further
advancement of the applicator 400 into the catheter will thereby
cause the ventricular winding 112 to unwind and straighten as it is
advanced into the catheter along with the applicator 400. It will
be appreciated that the center part of the ventricular winding 112
will be advanced into the catheter first, and the ventricular
winding 112 will unwind from the center to the outer periphery as
the ventricular winding 112 is advanced into the catheter. When
fully advanced into the catheter, the generally unwound ventricular
winding 112 is held in a relatively straightened position between
the outer wall of the applicator 400 and the inner wall of the
catheter lumen. The applicator 400 may be advanced into the
catheter either before or after the catheter is tracked to the
patient's heart.
[0076] The catheter is positioned adjacent the heart valve to be
treated, for example a mitral valve, by a method known in the art.
The approach may be, for example, a transseptal approach, with the
catheter entering the left atrium through the septum between the
right atrium and the left atrium. To facilitate a transseptal
approach, the delivery system may include an atrial septum dilator.
Other approaches alternatively may be used, including, for example,
a transfemoral approach through the femoral artery and through the
aorta and into the left ventricle, a transapical approach through
the heart wall at the heart apex into the left ventricle, or a
transatrial approach through the heart wall into the left atrium.
Similarly, when the valve to be treated is the tricuspid valve, the
catheter is positioned adjacent the valve by a method known in the
art (such as being introduced to the heart via a jugular vein or
the vena cava).
[0077] Once the guide catheter is adjacent the heart valve, the tip
of the guide catheter may be moved and/or turned so that it is
facing the heart valve leaflets. The applicator 400 then may be
advanced relative to the catheter, thereby ejecting the ventricular
winding 112 from the catheter. Because of the shape memory of the
ventricular winding 112, the heart valve repair device 110 returns
to a position as shown in FIGS. 7A and 7B, inside the heart. The
ejection of the ventricular winding 112 from the catheter may be
performed in the atrium. Alternatively, the ejection of the
ventricular winding 112 from the catheter may be performed in the
ventricle. If ejected in the atrium, the delivery system 300 then
may be used to advance the distal end of the applicator 400, and
with it the ventricular winding 112, into the ventricle. The distal
end of the applicator 400 and the ventricular winding 112 may be
pushed through the valve into the ventricle.
[0078] FIG. 8 shows a perspective view of the distal end of the
delivery system 300, with the ventricular winding 112 ejected from
the guide catheter and outside of the tube of the applicator 400,
and with the grasping element 120 still inside the tube of the
applicator 400 and connected to the hook 460. In this position,
rotation of the applicator 400 causes the heart valve repair device
110 to be rotated along with it. During rotation of the applicator
400, the action of the frame of the window 410 against the device
110 causes the device 110 to rotate with the applicator 400.
Additionally or alternatively, the hook 460 or another part of the
delivery system 300 may sufficiently hold the device 110 to cause
the device 110 to rotate. Due to the geometry of the device, the
axis of the delivery system can be generally aligned with the axis
of rotation of the ventricular winding.
[0079] In the condition as shown in FIG. 8, and with the
ventricular winding 112 positioned in the ventricle, the delivery
system may be used to capture the desired chords with the
ventricular winding 112. The physician may maneuver the ventricular
winding 112 from side to side to capture specific chords in order
to bring desired areas of the leaflets together. For example, by
suitably moving and turning the ventricular winding 112, the chords
associated with the leaflet areas A1 and P1 (FIG. 12) may be
captured. Additionally or alternatively, the chords associated with
the leaflet areas A2 and P2 and/or A3 and P3 (FIG. 12) may be
captured.
[0080] In this manner, the desired chords associated with the
anterior papillary muscle and the desired chords associated with
the posterior papillary muscle are positioned within the path 118
of the generally spiral shape of the ventricular winding 112. By
turning the ventricular winding 112, whether by turning the
applicator 400 or by another suitable mechanism, the ventricular
winding 112 is thereby turned to wind around the selected anterior
and posterior chords. As the ventricular winding 112 is turned, the
spiral shape forces the chords within the path 118 closer to the
center 114 of the ventricular winding 112. In this manner, the
captured anterior chords and posterior chords are forced closer
together, thereby reducing a gap between the selected chords
associated with the anterior papillary muscle and the selected
chords associated with the posterior papillary muscle. By doing
this, because the selected chords are attached to the selected
areas of the leaflets, the selected areas of the leaflets are
brought closer together.
[0081] In order that the ventricular winding may be turned to move
the chords in this manner and may hold the chords, the heart valve
repair device, or at least the ventricular winding, should have
sufficient stiffness such that the spiral shape is generally
maintained. Thus, the device should be sufficiently rigid so as to
maintain the spiral shape on its own and under the forces applied
to it by the chords.
[0082] In alternative embodiments in which the ventricular winding
comprises more than one spiral, the device may be formed so that it
can gather and move the chords with fewer rotations. Thus, for
example, with the ventricular winding comprising multiple spirals
and with the openings for the spirals positioned at different
places around the perimeter of the ventricular winding, chords at
different places around the perimeter of the ventricular winding
may be gathered simultaneously and moved toward the center
simultaneously.
[0083] In order to adjust the device, after the physician has
turned the ventricular winding 112 in a first direction as
described above, the physician may turn the ventricular winding 112
back in the opposite direction in order to allow the chords to move
apart by some amount. Thus, in this example, after the positioning
resulting from clockwise turning, the physician may turn the
ventricular winding 112 counterclockwise (when viewed from the top)
in order to allow the captured chords to move away from the center
114 of the ventricular winding 112, thereby allowing them to
separate by some distance. The physician can monitor the
positioning of the chords and leaflets and turn the ventricular
winding 112 clockwise or counterclockwise as needed in order to
obtain the desired result.
[0084] If desired, after the ventricular winding 112 has been
rotated into the desired rotational position, the physician may
pull the ventricular winding 112 to bring it closer to the heart
valve. This may be accomplished by retracting the applicator
400.
[0085] When the ventricular winding 112 is in the desired position,
the remainder of the device 110 is ejected from the applicator 400,
as shown in FIG. 9. With the applicator 400 held relatively stable,
the internal rod 450 is advanced distally within the applicator
400. This moves the hook 460 to be located at the window 410.
During this distal advancement, the grasping element 120 is
advanced distally against the ramp surface 420, which forces the
grasping element 120 away from the applicator 400 and the hook 460.
With the hook 460 in the window 410, the grasping element 120 is no
longer prevented from exiting the hook 460 by the internal wall of
the lumen of the applicator 400. The grasping element 120 is
released from the hook 460, and the device 110 is left in place.
The delivery device 300 is then withdrawn from the patient. This
leaves the heart valve repair device 110 implanted in the
patient.
[0086] If the procedure is one in which the valve is approached
from the atrium as described above, once the device is implanted in
the ventricle, the grasping element will be pointing generally
toward the atrium. If, on the other hand, the procedure is one in
which the valve is approached from the ventricle, once the device
is implanted in the ventricle, the grasping element will be
pointing generally away from the atrium and generally toward the
apex of the heart.
[0087] Other heart valve repair devices as described herein, such
as the heart valve repair devices 130, 150, 170, and 190, and the
variations described above with respect to the heart valve repair
devices 110, 130, 150, 170, and 190, may be implanted in a similar
manner as described above.
[0088] The inventive heart valve repair devices as described herein
provide certain advantages with respect to prior devices. As
discussed above, in prior heart valve repair devices for capturing
leaflet chords as exemplified in certain prior devices, the devices
have included parts or sections for anchoring the devices relative
to the atrium, in order to ensure that the devices remained stable
in the heart after implantation. By contrast, the inventive heart
valve repair devices 110, 130, 150, 170, and 190, and the
variations described above with respect to these devices, depart
from these prior teachings and are free of any atrial stabilizing
section. The inventors have found that not only is it possible to
implant the inventive heart valve repair devices and have them
remain stable in the heart after implantation despite the absence
of any atrial stabilizing section, but the inventors also have
found that the inventive heart valve repair devices provide
previously unrecognized advantages that could not be attained by
prior devices that were anchored to the atrium.
[0089] As the heart pumps, the various parts of the heart are in
motion. The chords connecting the papillary muscles to the leaflets
are in motion. A heart valve repair device as described herein
without any atrial stabilizing section is free to move along with
the chords, while at the same time retaining the chords in their
drawn-in condition for leaflet coaptation. Over time, tissue may
grow around the ventricular winding such that the ventricular
winding becomes substantially embedded in the chords. This tissue
enveloping of the device results in a fixation of the device to the
chords.
[0090] In prior devices that have included atrial stabilizing
sections, the devices have been anchored relative to the atrium.
However, during the beating of the heart and the opening and
closing of the valves, the chords move relative to the atrium.
Thus, when such a prior device is implanted and anchored to the
atrium, the chord movement relative to the atrium results in chord
movement relative to the device. A device anchored to the atrium is
constrained from moving freely with the chords. This constraint can
occur at the time of the implantation procedure and longer. When a
device is constrained in this manner, the chords can rub relative
to such a device, which can cause irritation, injury, and/or
rupture of the chords.
[0091] By contrast, a heart valve repair device as described
herein, without any atrial stabilizing section, can be affixed only
to the chords. Thus, the device is free to move along with the
chords, such as in an up-and-down direction generally in the
direction of the axis of implantation, while at the same time
maintaining the chords in their drawn-in condition for leaflet
coaptation. This movement of the device can occur relative to the
atrium. Thus, by being free of any atrial stabilizing section, the
device has the previously unrealized advantages of reducing or
eliminating the potential for chord movement relative to the device
and reducing or eliminating the consequent potential for
irritation, injury, and/or rupture of the chords that can be caused
by such relative movement.
[0092] While prior devices as discussed above have included atrial
anchoring in order to ensure stability after implantation, the
inventors have found that a device as described herein, in both ex
vivo testing and in vivo animal testing, is stable in the heart
after implantation, despite not having an atrial stabilizing
section. The device is sufficiently held in place by the
interaction between the ventricular winding and the chords.
Accordingly, the inventors have found that it is possible to
realize the advantages as described herein and have the device be
stable in the heart after implantation, without the need for a
connected atrial stabilizing section as in the prior devices
discussed above.
[0093] The use of a device without any atrial stabilizing section
can have several additional advantages. For example, by not having
an atrial stabilizing section, the device can be smaller, simpler
and less expensive to manufacture, easier to implant, more
maneuverable to facilitate targeted treatment, less prone to tissue
injury, and may improve overall outcome.
[0094] The presence of an atrial stabilizing section can result in
a relatively larger or longer device, requiring positioning the
device on the atrial side as well as on the ventricular side of the
valve. Thus, the device without any atrial stabilizing section can
lead to easier implantation. Implantation is also facilitated
because the device is easier to visualize without any atrial
stabilizing section.
[0095] Without an atrial stabilizing section, it can be easier to
maneuver the relatively small ventricular winding to capture
specific groups of chords. The presence of an atrial stabilizing
section can limit the range of placement of the device. That is, a
relatively large atrial stabilizing section can limit the
side-to-side range of the device, potentially limiting the areas in
which the device can be placed, and limiting the groups of chords
that can be captured. By contrast, the smaller, more maneuverable
device leads to an improved ability to address specific chords
and/or specific areas of a valve.
[0096] The device without an atrial stabilizing section also
reduces the chance of tissue injury on the atrial side of the
valve, which can occur due to the engagement of tissue on the
atrial side. Such engagement can occur during the delivery
procedure or after implantation.
[0097] A person of ordinary skill in the art will understand that
the various heart valve repair devices described herein may be
implanted according to the method described above. Various features
of the device can facilitate the procedure and functioning.
[0098] For example, the grasping element allows the device to be
held by the delivery system, so that it can be held, maneuvered,
turned, and released as described above. Because the grasping
element can extend from at or near the center of the ventricular
winding, the device can be turned by simply rotating the
ventricular winding generally around the axis of the grasping
element. When the device is fully deployed, the grasping element
may be located fully within the ventricle or may extend into the
atrium.
[0099] The end portion of the ventricular winding, bent away from
the general plane of the winding, can facilitate capturing of the
chords. The distance of the end portion away from the general plane
of the winding can determine the span of the potential chords to be
grasped. The rounded atraumatic tip of the end portion can help
prevent injury to the chords, leaflets, and/or other tissue.
[0100] When all or part of the ventricular winding is out of plane,
such as in a conical or partially-conical embodiment as shown in
FIGS. 2 and 3, the height dimension of the ventricular winding can
help maintain the vertical positioning of the device within the
ventricle. The height dimension also allows more contact with the
chords in the vertical direction. This can reduce the friction
between the device and the chords and can increase tissue coverage
of the device. In addition, the height dimension can allow easier
visualization of the device.
[0101] When the spacing of the turns of the ventricular winding is
larger toward the outer periphery, as shown in FIG. 4, the design
can facilitate capturing the chords (by the larger outer spacing)
while also bringing them close together (by the narrower inner
spacing).
[0102] The device can have anti-rotation elements that can help
prevent the ventricular winding from turning backward (in the
loosening direction) after implantation. Thus, the ventricular
winding can have one or more anti-rotation elements 191, 193, 195,
as shown in FIGS. 5A-5C, that help keep the device in place. Other
mechanisms for resisting unwinding include the use of different
shapes. For example, if the ventricular spiral is in an elliptical
shape, the chords will tend to gather in the apices of the long
axis of the ellipse. In order for the device to rotate, the chords
would need to be drawn closer together, which is a movement they
would tend to resist. Accordingly, such an elliptical shape can
assist in preventing an unwanted rotation of the device.
[0103] It will be appreciated that in procedures in which the
delivery system approaches the heart valve from the ventricular
side (e.g., in transfemoral and transapical approaches), similar
methods to those described above may be used, modified to account
for the fact that the delivery system approaches the valve from the
opposite side.
[0104] The delivery system may have means for retrieving and/or
moving the heart valve repair device after it has been partially or
fully deployed. For example, FIG. 10 shows a retraction wire 500
that may be placed inside the grasping element 121 of the heart
valve repair device. The retraction wire 500 can be located inside
the applicator 400, but can also remain inside the grasping element
121 after the heart valve repair device has been ejected from the
applicator 400. Pulling the retraction wire 500 can withdraw the
heart valve repair device back, so that it can be moved to a
different position or fully removed from the patient.
[0105] FIG. 11 illustrates an alternate form of a hook 470 used to
engage a relatively flat grasping element 472. As can be seen, in
this embodiment the grasping element 472 is generally in the same
plane as the ventricular winding. In this embodiment, the device is
released simply by turning the hook 470 relative to the grasping
element 472, such that the hook 470 can be withdrawn from the
grasping element 472.
[0106] While the above method has been described with respect to a
device in which the ventricular winding is positioned outside of
the applicator for delivery, as in FIG. 8, variations are possible.
For example, the ventricular winding may be positioned inside of
the applicator 400, whereby it is held in a relatively straightened
position. For deployment, the device is ejected from the
applicator, at which time the ventricular winding resumes its
spiral shape.
[0107] As would be understood from the above descriptions by
persons of ordinary skill in the art, alternative embodiments of
the devices 110, 130, 150, 170, and/or 190 may be implanted
generally as described above. The method of implantation may be
varied as appropriate with respect to the particular embodiment
used and the particular patient being treated.
[0108] When a device as described is placed in position as
described, the spiral of the ventricular winding reduces a gap
between selected chords associated with the anterior papillary
muscle and selected chords associated with the posterior papillary
muscle. In this manner, the selected areas of the leaflets of the
valve are drawn closer together. In some instances, the control of
the chords also can reduce the movement of the leaflets, in order
to help prevent prolapse. The control of the chords and the drawing
of the leaflets closer together facilitate coaptation of the
leaflets, such that they can close together sufficiently to correct
the regurgitation issue. The device can be left in place as a
long-term treatment.
[0109] FIG. 12 shows a top view of leaflets of a mitral valve. A
device as described herein may be used in various positions and for
gathering various chords. For example, the device may be positioned
approximately in the area of A2 and P2 near the center of the
anterior and posterior leaflets. The chords on A2 and P2 are
trapped and gathered by the spiral(s) of the ventricular winding. A
rotation of the spiral would eventually bring all such chords to
the same location, which is the spiral center. In this situation,
the gap between A2 and P2 could be brought to zero. Rotating the
spiral a little less would result in a narrow gap. The device
alternatively may be positioned approximately in the area of A1 and
P1, in which case the chords on A1 and P1 are trapped and gathered
by the spiral(s) of the ventricular winding, reducing the distance
between A1 and P1. The device alternatively may be positioned
approximately in the area of A3 and P3, in which case the chords on
A3 and P3 are trapped and gathered by the spiral(s) of the
ventricular winding, reducing the distance between A3 and P3. A
device with a large spiral positioned approximately in the area of
A2 and P2 may trap and gather chords on A2, P2, A1, P1, A3 and/or
P3, and can be used to reduce the distance between P1 and P3, for
example, or A1 and A3.
[0110] With a relatively small heart valve repair device as
described herein, for example having a ventricular winding with an
outside diameter of 1.0-2.0 centimeters, for example, it is
possible to capture less than substantially all of the chords and
to capture small groups of chords. Implanting such a device may
involve positioning the spiral of the ventricular winding between
chords rather than around substantially all of the chords. Also,
with a relatively small heart valve repair device as described
herein, it is possible to implant multiple devices, capturing
different sets of chords. The flow through the valve can be
adjusted by selectively adjusting the different devices. For
example, one device could be placed capturing the chords on A1 and
P1, a second device could be placed capturing the chords on A2 and
P2, and a third device could be placed capturing the chords on A3
and P3. The flow can be evaluated, and if necessary, adjusted. For
example, the device at A1 and P1 could be rotated to bring the
associated chords closer together, while the device at A3 and P3
could be rotated in an opposite direction.
[0111] In some instances, it may be desired to use the device to
draw the leaflets closer and then position a clip anchored to both
leaflets or stitch or suture the leaflets together. Thus, the
device in conjunction with one or more clips, stitches or sutures
can facilitate coaptation of the leaflets.
[0112] If desired, the device may be adjusted or withdrawn at a
later time, either shortly or long after the implantation. A
catheter may be used to access the device. To adjust the device,
the physician may turn the spiral of the ventricular winding as
described above (e.g., by turning the device) in order to bring the
chords closer together or to allow them to separate further apart,
as desired. Thus, the turning may be done while performing the
initial implantation procedure and/or as an additional later
procedure that is separate from the implantation procedure. In this
manner, the regurgitation grade can be controlled. Alternatively,
if it is desired to withdraw the device altogether, a grasping
mechanism may be used to grasp the device and pull it back into the
catheter, in essentially the reverse of the procedure that was used
to deliver the device.
[0113] Numerous alternatives are possible within the scope of the
invention. For example, as mentioned above, the winding of the
spiral may move away from the center at a non-constant rate. Thus,
the spiral density need not be constant.
[0114] If the device is formed as a tube, a wire or stiffening
element may be placed into the tube in order to change the
stiffness and/or shape of the tube or a section of it. For example,
a stiffening element may be used to maintain the device in a first
shape for delivery (e.g., relatively straight), and the stiffening
element may be withdrawn upon delivery of the device from the
delivery catheter in order to allow the device to take its
implantation shape. In another example, an inner wire may be
attached to the distal end of the tube, and the inner wire may be
pulled relative to the tube to change the shape of the tube.
Pulling the inner wire applies a compressive force to the tube. The
tube may be formed with pre-shaped side cuts along the tube, such
that it bends in a predetermined pattern, e.g., a spiral pattern,
when such a load is applied. A locking mechanism may be used to
lock the wire in its loaded position relative to the tube.
Different depths and widths of the side cuts and the distance
between the side cuts would determine the final shape of the tube
element once a load is applied.
[0115] The device may have other elements to monitor the
functioning of the device and the heart valve. For example, the
device may be equipped with a sensor attached to the device. The
sensor may be, for example, a pressure sensor, a temperature
sensor, and/or a velocity sensor. In this way, the operation of the
valve and the blood flow can be monitored. Similarly, the device
itself when formed as a tube can be used as a "pig tail" for
measuring pressure during or after the implantation procedure.
[0116] In one example of the use of sensors, the use of MEMS
(microelectromechanical systems) sensors on the device may assist
in the implantation procedure or during the years after it. Such
sensors may monitor temperature, oxygen saturation, pressure, blood
velocity or similar physical characteristics. During the
implantation procedure, it is possible to use an xyz (positioning)
sensor on the device to assist in the accurate location and
positioning of the device by using an external system that reads
the information transmitted from the sensor.
[0117] Sensor(s) on the device or delivery system may be part of a
closed-loop system that uses the signals from the sensor(s) as
feedback for automatic delivery and positioning. By using pressure
sensors in the ventricle and atrium, the pressure can be
continuously monitored as the device is automatically adjusted. The
adjustments and monitoring can be continued until target pressure
readings are achieved. This automatic positioning with the use of
feedback can eliminate the need for manual monitoring and
positioning that can be complicated and less accurate.
[0118] The device may also have an energy-producing element that
produces energy by the flow of blood around the device and/or by
the pressure changes using a converter (such as piezoelectric
element that is capable of converting mechanical pulse into
electric current). The energy may charge a battery that, for
example, can be used to transmit signals from one or more sensors
as described above.
[0119] From the description herein, a person of ordinary skill in
the art can recognize that certain embodiments of devices and
methods disclosed herein can have several advantages. For example,
the device can safely hold the chords without requiring grasping of
the leaflets. The movement of the chords toward each other can be
controlled by the structure of the device, including, for example,
the number of turns of the spiral of the ventricular winding, the
radii of those turns, and their shape.
[0120] Based on the above description and the accompanying
drawings, the principles and operation of the invention, as well as
how to make and use the invention, can be understood by persons of
ordinary skill in the art. Many embodiments and variations are
possible that take advantage of the principles and operation of the
invention described herein. The examples described herein and shown
in the accompanying drawings are meant as examples only and are not
intended to be limiting of the scope of the invention defined by
the appended claims.
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