U.S. patent application number 13/673886 was filed with the patent office on 2013-03-21 for leaflet reinforcement for regurgitant valves.
The applicant listed for this patent is David J. McKinley, Robert Foster Wilson. Invention is credited to David J. McKinley, Robert Foster Wilson.
Application Number | 20130073034 13/673886 |
Document ID | / |
Family ID | 47881378 |
Filed Date | 2013-03-21 |
United States Patent
Application |
20130073034 |
Kind Code |
A1 |
Wilson; Robert Foster ; et
al. |
March 21, 2013 |
Leaflet Reinforcement For Regurgitant Valves
Abstract
A support, and a method for attaching said support, for
providing additional strength to existing regurgitant or prolapsed
valve leaflets. The support restores an otherwise non-functioning,
or poorly functioning, native valve to a functioning condition,
obviating the need for a complete valve removal or replacement. The
support may also be applied to a functioning valve leaflet as a
prophylactic measure against future failure. The delivery method
includes a delivery mechanism for attaching the support to the
native valve leaflet.
Inventors: |
Wilson; Robert Foster;
(Roseville, MN) ; McKinley; David J.;
(Minneapolis, MN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Wilson; Robert Foster
McKinley; David J. |
Roseville
Minneapolis |
MN
MN |
US
US |
|
|
Family ID: |
47881378 |
Appl. No.: |
13/673886 |
Filed: |
November 9, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10613121 |
Jul 3, 2003 |
8348963 |
|
|
13673886 |
|
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Current U.S.
Class: |
623/2.11 ;
623/2.36 |
Current CPC
Class: |
A61F 2/2442 20130101;
A61F 2/2463 20130101; A61F 2/2436 20130101; A61F 2/2454
20130101 |
Class at
Publication: |
623/2.11 ;
623/2.36 |
International
Class: |
A61F 2/24 20060101
A61F002/24 |
Claims
1. A device useable to attach a support to a valve leaflet
comprising: a sheath; a delivery mechanism slideably disposed
within the sheath, said delivery mechanism constructed and arranged
to carry at least one support, whereby when said sheath is
retracted to expose said delivery mechanism, said delivery
mechanism is moveable such that the support is pressed against the
valve leaflet.
2. The device of claim 1 wherein said delivery mechanism comprises
at least one delivery arm pivotally attached to a carrier.
3. The device of claim 2 further comprising at least one activation
string operably connected to said at least one delivery arm such
that pulling said at least one activation string causes said at
least one delivery arm to pivot.
4. A device useable to support a prolapsed valve leaflet,
comprising: a support; an attachment mechanism, operably attached
to the support member, and useable to attach the support member to
a prolapsed valve leaflet.
5. The device of claim 4 wherein said support comprises a first
part pivotally connected to a second part.
6. The device of claim 5 further comprising a hinge pivotally
connecting said first and second parts.
7. The device of claim 4 wherein said support comprises at least
one elongate beam.
8. The device of claim 4 wherein said support comprises
Nitonol.
9. The device of claim 4 wherein said support comprises an open
network of support members.
10. The device of claim 4 wherein said support comprises a covered
network of support members.
11. The device of claim 4 wherein said support comprises a
substrate.
12. The device of claim 11 wherein said substrate is curved,
forming a concave side and a convex side, the concave side facing a
downstream direction when the device is attached to a prolapsed
valve leaflet.
13. The device of claim 11 wherein said substrate is attachable to
an upstream side of a prolapsed valve.
14. The device of claim 11 wherein said substrate is attachable to
a downstream side of a prolapsed valve.
15. The device of claim 4 wherein said attachment mechanism
comprises barbs.
16. The device of claim 4 wherein said attachment mechanism
comprises staples.
17. The device of claim 4 wherein said attachment mechanism
protrudes from an upstream side of said support.
18. The device of claim 4 wherein said attachment mechanism
protrudes from a downstream side of said support.
19. The device of claim 4 wherein said support comprises an
upstream member constructed and arranged for placement on an
upstream side of a prolapsed valve leaflet, and a downstream member
constructed and arranged for placement on a downstream side of the
prolapsed valve leaflet.
20. The device of claim 19 wherein said attachment mechanism
operably connects the upstream member to the downstream member,
such that the prolapsed valve leaflet is sandwiched between the
upstream member and the downstream member.
21. The device of claim 19 wherein said attachment mechanism
comprises a magnetic field operably connecting the upstream member
to the downstream member.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of U.S. patent application
Ser. No. 10/613,121 filed Jul. 3, 2003 entitled Leaflet
Reinforcement For Regurgitant Valves, which claims the benefit of
U.S. Provisional Application No. 60/393,794, filed Jul. 3, 2002,
the contents of both of which are hereby incorporated by reference
in their entireties.
BACKGROUND OF THE INVENTION
[0002] Blood vessel valves include flexible tissue leaflets that
passively alternate between open and closed positions as the forces
of a blood stream act upon them. As blood flows in a first
direction, the leaflets are urged apart from each other, and allow
the blood to pass. Between pulses, as the blood attempts to flow in
a reverse direction, the blood acts upon upstream surfaces of the
individual leaflets, causing the leaflets to move inwardly. As the
leaflets move inwardly, the edges of the individual leaflets (two,
in the case of bicuspid valves, and three in the case of tricuspid
valves) abut against each other, effectively blocking the blood
flow in the reverse direction.
[0003] If the individual leaflets suffer degradation in structural
integrity, such as degeneration, a prolapse condition may result.
FIGS. 1 through 3 demonstrate the mechanics of a regurgitant valve
with leaflet prolapse. FIGS. 1a and 1b show a healthy tricuspid
valve 1 in the open position. The direction of blood flow is
indicated by arrow 2. The valve 1 includes three leaflets 3 growing
into the lumen of a blood vessel 4. It can be seen that when the
blood is flowing in the direction shown by arrow 2 of FIG. 1a, the
flexible valve leaflets 3 naturally fold themselves against the
interior walls of the blood vessel 4, thereby minimizing their
impact on blood flow in that direction.
[0004] As depicted in FIG. 2a, when blood attempts to flow in the
reverse direction, between cardiac pulses, these valve leaflets 3
move inward, toward each other. As best shown in FIG. 2b, when the
leaflets 3 abut, they form a seal 5, effectively preventing fluid
flow in the direction of arrows 2 from FIG. 2a. The seal 5 can only
be formed if all three valve leaflets 3 are structurally sound.
[0005] When a valve, such as valve 1 of FIG. 3, has a prolapsed
leaflet 3a, the seal 5 cannot be effectively formed. Leaflet 3a
lacks the structural integrity of the healthy leaflets 3. When the
flow is reversed, as indicated by arrow 2, the healthy leaflets 3
balloon inwardly. However, the prolapsed leaflet 3a falls away from
the seal 5, leaving a significant gap 6 in the seal 5. Blood passes
through the gap 6, resulting in a loss of systolic pressure, as
well as a reduction in the pumping efficacy of the heart.
[0006] Current methods of repairing prolapsed valves involve
replacing the valve entirely with a prosthetic valve. The
structurally sound leaflets are not preserved. It would be
advantageous to provide a method of repairing a prolapsed valve,
leaving as much of the native valve as possible intact, thereby
minimizing the risk of rejection, and preserving the healthy
leaflets. Percutaneous treatment would obviate the risks associated
with open heart surgery.
SUMMARY OF THE INVENTION
[0007] In one aspect of the present invention, there is a method
for repairing a prolapsed valve that involves reinforcing the
prolapsed leaflet or leaflets to reestablish the structural
integrity thereof. The method involves attaching a support to one
or both sides of the valve. The support is constructed and arranged
to allow the leaflet to open when blood is flowing through the
valve in the natural direction. When the flow is reversed during a
diastole, the support resists, preventing the leaflet from
prolapsing.
[0008] In another aspect of the present invention, a support is
provided that is attachable to the downstream side of a prolapsed
valve leaflet. The support includes an attachment mechanism,
preferably barbs, staples, or similar suitable tissue-grabbing
means. The support may be bifurcated with one or more hinge,
allowing one side of the support to pivot relative to the second
side. The hinge is constructed and arranged with a stop, so that
the hinge prevents pivoting past a sealing point. Preferably, the
hinge is constructed to avoid pinching the leaflet tissue with the
stop is reached.
[0009] Another aspect of the present invention provides a support
that is attachable to the upstream side of a prolapsed valve
leaflet. The construction of the upstream support is very similar
to that of the downstream support. The upstream support also
includes an attachment mechanism, preferably barbs, staples, or
similar suitable tissue-grabbing means. Again, the support may be
bifurcated with one or more hinge, allowing one side of the support
to pivot relative to the other side. The hinge is also constructed
and arranged with a stop, so that the hinge prevents pivoting past
a sealing point. Placing the support on the upstream side of the
valve may be advantageous because the stress encountered during
diastole, when the support is preventing the leaflet from
prolapsing due to the pressure of the blood, acts in conjunction
with the attachment mechanism, rather than against it. Thus, the
support is less likely to become separated from the leaflet.
[0010] Yet another aspect of the present invention provides a
support that includes both upstream and downstream members. These
members are similar in construction to the upstream and downstream
members. However, the attachment mechanism used in this aspect
takes advantage of the additional structure provided by the
opposing support. The opposing supports lock together, through the
prolapsed leaflet, sandwiching the leaflet therebetween.
Preferably, one member includes male connectors, while the other
member includes corresponding female connectors. Alternatively,
each side includes one or more male and one or more female
connectors, and the other member includes corresponding mating
connectors. Whereas the downstream member may provide a single
hinge, the upstream member may provide a double or triple hinge,
constructed and arranged to allow the upstream member to move with
the downstream member, without changing the relative position
between the two members. Providing such an arrangement avoids the
occurrence of locked hinges and/or tearing the leaflet tissue
between the two members. Alternatively, one or both supports may be
hingeless.
[0011] Still another aspect of the present invention provides a
support with a more complex, multi-member structure, flexible in
one direction but rigid in another direction. This structure
obviates the necessity of hinges. The support members form a frame
with either an open or covered interior.
[0012] A further aspect of the present invention includes a woven,
pressed, laminar or similar substrate-like hingeless support. This
support operates on the principle that strength is achieved in an
otherwise flimsy substrate when the substrate is curved. This
principle is easily demonstrated by holding a piece of paper while
imparting a curve onto the paper with one's fingers. The paper can
be made to easily support itself or even to hold other objects on
the concave side, without supporting opposite sides of the paper.
However, placing pressure on the convex side of the curved paper
causes the paper to quickly bend. Steel tape measures operate on
this principle. The tape measures are curved and can be bent easily
in one direction but are relatively rigid in the opposite
direction.
[0013] Yet another aspect of the present invention includes a
method of attaching a support to a prolapsed valve leaflet. The
method involves passing a wire from the aorta through the prolapsed
valve. A catheter is then guided over the wire that contains the
support mechanism. Preferably, the support mechanism includes a
biasing means that allows the support to be pre-loaded in the
catheter such that, when released from the catheter sheath, the
support mechanism attaches itself to the prolapsed valve leaflet.
Alternatively, a positioning means is provided so the support
members do not require pre-loading in the catheter unit. The
positioning means would allow manual manipulation of the support
members during placement. The support is preferably removably
attached to the leaflet, thereby allowing removal and reattachment
if necessary.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1a is a sectional view of a healthy native tricuspid
valve in an open position;
[0015] FIG. 1 b is a sectional view of the valve of FIG. 1a taken
along lines 1 b-1 b;
[0016] FIG. 2a is a sectional view of a healthy tricuspid valve in
a closed position;
[0017] FIG. 2b is a sectional view of the valve of FIG. 2a taken
along lines 2b-2b;
[0018] FIG. 3a is a sectional view of a native prolapsed valve;
[0019] FIG. 3b is a sectional view of the valve of FIG. 3a taken
along lines 3b-3b;
[0020] FIG. 4 is a perspective view of an unhinged downstream
embodiment of the present invention;
[0021] FIG. 5 is a perspective view of a hinged downstream
embodiment of the present invention;
[0022] FIG. 6 is an end view of the embodiment of FIG. 5 attached
to a valve leaflet;
[0023] FIG. 7 is a perspective view of a downstream hinge of the
present invention;
[0024] FIG. 8 is a perspective view of an unhinged upstream
embodiment of the present invention;
[0025] FIG. 9 is a perspective view of a hinged upstream embodiment
of the present invention;
[0026] FIG. 10 is a side elevation of a hinged embodiment of the
present invention having members on both the upstream and
downstream sides of a prolapsed leaflet;
[0027] FIG. 11 is a perspective view of a substrate embodiment of
the present invention in a closed position;
[0028] FIG. 12 is a perspective view of a substrate embodiment of
the present invention in an open position;
[0029] FIG. 13 is a perspective view of a multi-member structure
embodiment of the present invention;
[0030] FIGS. 14a-d are a series of drawings depicting a preferred
method of attaching a support to a prolapsed leaflet;
[0031] FIG. 15 is an elevation of a preferred delivery device of
the present invention; and,
[0032] FIG. 16 is a perspective view of a preferred delivery device
of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0033] Referring now to the Figures, and first to FIG. 4, there is
shown unhinged embodiment of a support 10 of the present invention.
Support 10 includes a support member 12, which is curved to
approximately match the curve of a healthy valve leaflet in a
closed position. The curve defines a convex side 14 and a concave
side 16 of the support member 12. A plurality of barbs 18 extend
from the support member 12, and are constructed and arranged to
penetrate and catch the tissue of a prolapsed leaflet, securing the
support member 12 thereto. That the barbs 18 extend from the convex
side indicates that the support 10 of FIG. 4 is constructed and
arranged for attachment to the downstream side of a prolapsed
leaflet.
[0034] The support 10 is a biocompatible material. Acceptable
biocompatible metals that could be used to construct the support 10
include, but are not limited to, Nitonol, stainless steel,
titanium, and other appropriate metals. Acceptable non-metal
biocompatible materials include, but are not limited to, PTFE,
pyrolytic carbon, or any appropriate polymer.
[0035] FIG. 5 shows a hinged embodiment of a support 10. The
support 10 is bifurcated into a first part 20 and a second part 22.
The first part 20 and the second part 22 are connected with a hinge
24, which allows the second part 22 to rotate relative to the first
part 20. Rather than the barbs 18 shown in FIG. 4, the support 10
of FIG. 5 uses a plurality of staples 26 as an attachment
mechanism. FIG. 6 shows the staples 26 attaching the support 10 to
a valve leaflet 3. The staples 26 are shown with a hinged
embodiment 10 but there is no association between the staples 26
and the hinge 24. The barbs 18 of FIG. 4 could be used with a
hinged embodiment of support 10, and vice versa.
[0036] The hinge 24 is preferably designed to prevent pinching the
valve leaflet 3 during operation. FIG. 7 provides a detailed view
of the hinge 24. It can be seen that the hinge 24 includes a first
part component 28, integral with the first part 20 and a second
part component 30 integral with the second part 22. The components
28 and 30 are constructed and arranged to form an interfering stop
32 on a side opposite of the valve leaflet 3.
[0037] FIG. 8 shows a support 10 constructed and arranged for
attachment to an upstream side of a valve leaflet. Again, the
support member 12 has a convex side 14 and a concave side 16.
However, the attachment mechanism, shown as barbs 18, protrudes
from the concave side 16, placing the support member 12 on the
upstream, convex side of the leaflet.
[0038] FIG. 9 shows a hinged support 10 constructed and arranged
for attachment to an upstream side of a valve leaflet. Again, the
attachment mechanism, a plurality of barbs 18, protrudes from the
concave side 16. The hinge 24 of the upstream, hinged embodiment
includes a stop on the upstream side, so as to prevent pinching the
leaflet tissue.
[0039] FIG. 10 shows a support 10 that provides additional support
and is less reliant on the structural integrity of the leaflet
tissue for attachment purposes than the aforementioned embodiments.
The support 10 includes an upstream member 32 and a downstream
member 34. The upstream member 32 is attached to the downstream
member 34 through the valve leaflet 3 with an attachment mechanism
36. The attachment mechanism 36 shown includes a plurality of male
posts 38 that extend through and engage corresponding apertures 40
through the downstream member 34. A variety of alternatives may be
effectively used as attachment mechanism 36. For example, the male
posts could extend from the downstream member 34 into the upstream
member 32. Each support 32 and 34 could include both posts and
apertures for engaging a corresponding pattern in the opposing
support. The apertures do not have to extend through to the
opposite side of the defining support. Also, one or both supports
could employ magnets that cause the two supports 32 and 34 to be
attracted to each other across the leaflet tissue 3.
[0040] The support 10 of FIG. 10 also includes a hinge assembly 42,
however an unhinged two-sided support is also considered within the
scope of the present invention. The hinge assembly 42 includes a
single hinge 24 on the downstream member 34, which may be similar
to the hinge shown in FIG. 7. The upstream member 32 includes two,
or preferably three hinges 44 interconnected with connecting
members 46. The connecting members 46 add length to the hinge
assembly 42 such that, when the support 10 bends to an open
position, the upstream and downstream members 32 and 34 do not move
relative to each other.
[0041] FIG. 11 shows an alternative design for a support 10 that
incorporates a substrate 48. The substrate 48 is preferably a
flexible, biocompatible fabric that is at least somewhat resistant
to stretching and compressing. The substrate is curved around a
longitudinal axis 50 to form a concave side 52 and a convex side
54. The curve is imparted to the substrate 48 using a heat,
mechanical, or chemical forming process. Alternatively, or
additionally, a curved brace 56 is included at one end of the
support 10 that is to be placed near the base of the valve leaflet,
proximal the arterial wall.
[0042] Imparting a curve around the longitudinal axis 50 provides a
directional strength to the support 10 that lends itself to the
application of supporting a prolapsed valve leaflet. As seen in
FIG. 12, when blood flows in a systolic direction, the blood pushes
on the convex side 54 of the support 10 and causes the support to
buckle, allowing the blood to pass through the valve. The curve
does not add significant strength to the support 10 in this
direction. However, when the pressure reverses, such as during
diastole, the support 10 snaps back into the closed position shown
in FIG. 11.
[0043] Pressure against the concave side 52 is met with the
resistance imparted to the support 10 by the curve, preventing the
support 10 from buckling toward the convex side 54.
[0044] The support 10 of FIGS. 11 and 12 is versatile enough to be
placed on either or both sides of a prolapsed valve. Attachment
mechanisms such as staples, permanent sutures, adhesives, magnets,
or the like could be used to secure the support 10 to the valve
leaflet.
[0045] FIG. 13 shows another embodiment of a support 10 attached to
a prolapsed valve leaflet 3. The support 10 includes a network 58
of interconnected structures 60. The structures 60 are constructed
and arranged to allow the support 10 to bend in a downstream
direction to an open position, yet provides resistance to bending
in an upstream direction during a diastole. The support 10 may
include a covering over the network 58 or the network 58 may remain
open.
[0046] A method of securing a support 10 to a prolapsed valve
leaflet 3 is illustrated in FIGS. 14a-d. A guide wire 62 is
threaded through a blood vessel 4 to the site where the support 10
is to be installed. A catheter sheath 64, containing the support
10, is then fed along the guide wire 62 until the valve 1 is
reached and the support 10 is adjacent the target leaflet 3. The
sheath 64 is then carefully retracted until the support 10 is
exposed and free to rotate.
[0047] The support 10 is attached at one end to a delivery
mechanism 66, best shown in FIGS. 15 and 16. The delivery mechanism
66 is used to rotate the support 10 into place after the sheath 64
is removed. Rotation is achieved by manually pulling on activation
strings 68. When the strings 68 are pulled, the delivery arms 70
rotate around axles 72 in the directions shown by arrows 74 (FIG.
14d). The support 10, being temporarily attached to the delivery
arms 70, rotate therewith. It may be necessary to hold a carrier
76, on which the arms 70 are pivotally mounted, when pulling the
strings 68, in order to maintain the position of the delivery
mechanism 66. Once in place, the attachment mechanism of the
support penetrates the leaflet, or otherwise fixes the support 10
to the leaflet, and allows the delivery arms 70 to be dislodged
from the support 10. The delivery mechanism 66 and guide wire 62
are then retracted into the sheath 64 and the sheath 64 is removed
from the patient.
[0048] The delivery mechanism 66 is shown in FIG. 15 as delivering
a support 10 that includes both an upstream member 32 and a
downstream member 34. However, the same delivery mechanism 66,
having two delivery arms 70, could also be used to deliver supports
having only one support member, either upstream or downstream. The
unused arm 70 provides a surface against which the other arm acts
to secure the support to the leaflet. The unused arm also provides
a surface against which staples, if used as an attachment
mechanism, can be folded into an attached arrangement.
[0049] The foregoing description addresses embodiments encompassing
the principles of the present invention. The embodiments may be
changed, modified and/or implemented using various types of
arrangements. Those skilled in the art will readily recognize
various modifications and changes that may be made to the invention
without strictly following the exemplary embodiments and
applications illustrated and described herein, and without
departing from the scope of the invention, which is set forth in
the following claims.
* * * * *