U.S. patent application number 17/013613 was filed with the patent office on 2020-12-24 for device and method for improving the function of a heart valve.
This patent application is currently assigned to Medtentia International Ltd., Oy. The applicant listed for this patent is Medtentia International Ltd., Oy. Invention is credited to Olli Keranen.
Application Number | 20200397580 17/013613 |
Document ID | / |
Family ID | 1000005073879 |
Filed Date | 2020-12-24 |
![](/patent/app/20200397580/US20200397580A1-20201224-D00000.png)
![](/patent/app/20200397580/US20200397580A1-20201224-D00001.png)
![](/patent/app/20200397580/US20200397580A1-20201224-D00002.png)
![](/patent/app/20200397580/US20200397580A1-20201224-D00003.png)
![](/patent/app/20200397580/US20200397580A1-20201224-D00004.png)
![](/patent/app/20200397580/US20200397580A1-20201224-D00005.png)
![](/patent/app/20200397580/US20200397580A1-20201224-D00006.png)
![](/patent/app/20200397580/US20200397580A1-20201224-D00007.png)
![](/patent/app/20200397580/US20200397580A1-20201224-D00008.png)
![](/patent/app/20200397580/US20200397580A1-20201224-D00009.png)
![](/patent/app/20200397580/US20200397580A1-20201224-D00010.png)
United States Patent
Application |
20200397580 |
Kind Code |
A1 |
Keranen; Olli |
December 24, 2020 |
Device and Method for Improving the Function of a Heart Valve
Abstract
A device and method for improving the function of a heart valve
involves insertion of a device having a first and a second shape
into the heart valve. Two contact points of the device in the first
shape are separated by a distance essentially corresponding to a
distance between two commissures of the heart valve and separated
by an increased distance in the second shape. The device is
inserted into the heart valve to establish a contact between the
contact points and the commissures and transformed from the first
shape to said second shape in abutment with valve tissue throughout
a cycle of heart action. The device may change the shape of the
heart valve by stretching it between the commissures for improving
the ability of the heart valve to close.
Inventors: |
Keranen; Olli; (Bjarred,
SE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Medtentia International Ltd., Oy |
Espoo |
|
FI |
|
|
Assignee: |
Medtentia International Ltd.,
Oy
Espoo
FI
|
Family ID: |
1000005073879 |
Appl. No.: |
17/013613 |
Filed: |
September 6, 2020 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
16246374 |
Jan 11, 2019 |
10765516 |
|
|
17013613 |
|
|
|
|
11793028 |
Jun 14, 2007 |
10201424 |
|
|
PCT/SE05/01914 |
Dec 14, 2005 |
|
|
|
16246374 |
|
|
|
|
60636096 |
Dec 16, 2004 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61F 2/2445 20130101;
A61F 2250/0007 20130101; A61F 2220/0008 20130101 |
International
Class: |
A61F 2/24 20060101
A61F002/24 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 15, 2004 |
SE |
0403046-6 |
Claims
1-5. (canceled)
6. A method for improving the function of a heart valve comprised
of valve tissue including an annulus, leaflets and at least a first
commissure and a second commissure between adjacent leaflets, said
method comprising: inserting a device in a first shape into the
heart valve, said device comprising an elongate part comprising a
first contact point and a second contact point; establishing
contact between the first contact point and the valve tissue at
said first commissure and establishing contact between the second
contact point and the valve tissue at said second commissure;
causing a change in shape of the device from said first shape to a
second shape such that a distance between the first and second
contact points of the device is increased and the elongate part is
less arcuate between the first contact point and the second contact
point in the second shape and, consequently, a distance between the
first and second commissures of the heart valve is increased to
stretch the opening of the heart valve and change the shape of the
heart valve such that free edges of the leaflets are brought closer
together in a remodeled shape; attaching a fixation device to a
portion of the device arranged to receive the fixation device, to
attach the device to the valve tissue; and causing said device,
along its length, to contact the valve tissue throughout a cycle of
heart action so that said length of said device is encapsulated
with valve tissue over time.
7. The method of claim 6, comprising causing the elongate part,
when the device is in the second shape, to extend along the valve
tissue substantially in a plane of the annulus.
8. The method of claim 6, wherein said causing of the change in
shape of the device comprises releasing a restraint on the
device.
9. The method of claim 6, comprising extending a restraining wire
between portions of the elongate part to keep the first contact
point and the second contact point at a maximum distance from each
other in the first shape.
10. The method of claim 6, wherein said causing of the transfer of
shape of the device comprises activating a shape memory of the
device.
11. The method of claim 10, wherein the device comprises a
shape-memory material and the method comprises heating the device
above a transition temperature, whereby the device transforms into
an austenitic state and assumes the second shape as a programmed
shape.
12. The method of claim 6, wherein the change in shape of the
device from the first shape to the second shape creates a 40%
increase in the distance between the first and second contact
points for remodeling the heart valve.
13. The method of claim 6, comprising attaching a suture or clip as
a fixation device to said portion of the device.
14. The method of claim 6, wherein the portion arranged to receive
the fixation device is arranged at the contact points.
15. The method of claim 6, comprising arranging the fixation device
on the device so that the fixation device penetrates into valve
tissue for attaching the device to the valve tissue and fix the
device in the second shape.
16. The method of claim 6, comprising arranging any of hook-shapes,
protrusions, barbs, or spikes, in the tissue to attach the
device.
17. The method of claim 6, comprising arranging the elongate part,
in the second shape, in a form that corresponds to at least a part
of the annulus.
18. The method of claim 6, comprising arranging the elongate part
to extend along the valve tissue in a plane of the annulus while
the first and second contact points are arranged in contact with
the first and second commissures.
19. The method of claim 6, wherein the device is ring-formed to
extend mainly along the annulus of the heart valve.
20. The method according to claim 19, wherein the ring form
deviates from the shape of the annulus at the commissures for
allowing contact between the device and the commissures.
21. The method of claim 6, comprising placing the device in contact
with the chordae of the heart valve such that the device abuts a
ventricular side of the heart valve.
22. The method of claim 6, wherein the device is resilient such
that, when deformed into the first shape, an internal force strives
to assuming the second shape.
23. The method of claim 6, wherein the device is flexible in its
second shape to allow movements of the annulus and the first and
second commissures during heart action while still keeping the
first and second commissures stretched apart in the remodeled
shape.
Description
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 16/246,374 filed Jan. 11, 2019, which is a
continuation of U.S. patent application Ser. No. 11/793,028 filed
Jun. 14, 2007, which is the U.S. National Phase of and claims
priority to International Patent Application No. PCT/SE2005/001914,
International Filing Date Dec. 14, 2005, which claims benefit of
and priority to U.S. Provisional Application Ser. No. 60/636,096
filed Dec. 16, 2004 and Swedish Application No. 0403046-6 filed
Dec. 15, 2004, all of which are hereby incorporated herein by
reference in their entireties.
FIELD OF THE INVENTION
[0002] The present invention generally relates to improving the
function of a heart valve. More specifically, the invention relates
to a device and a method for treating heart valves having various
malformations and dysfunctions.
BACKGROUND OF THE INVENTION
[0003] Diseased mitral and tricuspid valves frequently need
replacement or repair. The mitral and tricuspid valve leaflets or
supporting chordae may degenerate and weaken or the annulus may
dilate leading to valve leak (insufficiency). The leaflets and
chords may become calcified and thickened rendering them stenotic
(obstructing forward flow). Finally, the valve relies on insertion
of the chordae inside the ventricle. If the ventricle changes in
shape, the valve support may become non-functional and the valve
may leak.
[0004] In valve repair, a diseased valve is left in situ and
surgical procedures are performed to restore its function. There
are numerous approaches for repairing a heart valve in order to
restore or improve its function. Frequently an annuloplasty ring is
used to reduce the size of the annulus. The ring serves to reduce
the diameter of the annulus and allow the leaflets to oppose each
other normally. Sutures are used to attach a prosthetic ring to the
annulus and to assist in plicating the annulus.
[0005] According to another method, the leaflets are attached to
each other at free edges of the leaflets by means of sewing or a
clip. This implies that two orifices are created, one on each side
of the attachment of the leaflets. These double orifices may then
close properly.
[0006] An example of a clip for attaching the leaflets to each
other is disclosed in US 2004/0220593.
[0007] In U.S. Pat. No. 6,723,038, there is disclosed devices for
improving mitral valve function. One device comprises a splint for
improving the function of a valve of a heart. The splint includes
an elongate member configured to be positioned transverse a heart
chamber so that each end of the elongate member extends through a
wall of the heart, and first and second anchoring members
configured to be positioned external the chamber and attached to
the ends of the elongate member to fix the elongate member in a
position across the chamber. The first anchoring member includes a
first portion configured to contact a first region of the heart
proximate the valve annulus to change a shape of the valve annulus
by compressing the heart. The change of shape of the valve annulus
helps restoring the heart function. However, using this device, the
elongate member will be placed in the blood flow and therefore the
patient will need lifelong anti-thrombosis treatment in order to
prevent blood clots forming within the blood flow.
SUMMARY OF THE INVENTION
[0008] It is an object of the invention to provide a more easily
accomplished valve repair to provide improved heart valve function.
It is a specific object of the invention to accomplish a valve
repair that does not interfere with the blood flow through the
heart valve.
[0009] These and other objects of the invention are accomplished by
means of a device and a method according to the independent claims.
Preferred embodiments of the invention are apparent from the
dependent claims.
[0010] Thus, there is provided a device for improving the function
of a heart valve comprised of valve tissue including an annulus,
leaflets and at least a first and a second commissure between
adjacent leaflets. The device has a first shape and a second shape
and comprises a first contact point and a second contact point,
wherein the device in the first shape exhibits a distance between
the first contact point and the second contact point essentially
corresponding to a distance between said first and second
commissure of the heart valve and the device in the second shape
exhibits an increased distance between the first and the second
contact points. In the first shape, the device is arranged for
insertion to the heart valve to establish a contact between the
first contact point and valve tissue at the first commissure and to
establish a contact between the second contact point and valve
tissue at the second commissure. The device is transferable from
said first shape to said second shape when inserted to the heart
valve, and, in the second shape, the device is arranged for
extending along substantially its entire length between the first
contact point and the second contact point in abutment with valve
tissue throughout a cycle of heart action.
[0011] The device may be inserted into a heart valve in the first
shape of the device and the device may change the shape of the
heart valve by stretching the heart valve between the commissures.
The stretching of the heart valve between the commissures implies
that mid-portions of the leaflets are brought closer together.
Thereby, the ability of the leaflets to close the heart valve
properly is improved.
[0012] The invention provides a device that may be used in a simple
manner for improving the function of a leaking heart valve. The
device is arranged for accomplishing a change of the geometrical
shape of the heart valve so as to improve the ability of the
leaflets to close properly. Whereas known methods of changing the
shape of the heart valve for treating a leaking valve have been
focused at compressing the heart valve, the present invention
provides a device to be used for stretching the heart valve in the
direction of the heart valve opening. The invention is thus based
on an insight that a leaking heart valve may be treated by
accomplishing a change of the geometrical shape of the valve by
stretching the valve in a certain direction instead of compressing
the valve.
[0013] The device provides a first shape which is designed to fit
the heart valve such that contact may be established between the
device and two commissures of the heart valve. Therefore, the
device presents a distance between two contact points that
essentially correspond to a distance between the two commissures of
the heart valve. The device need not be placed in contact exactly
in the commissure, but may make contact with valve tissue in the
proximity of the commissure. Therefore, the distance between the
contact points of the device in the first shape of the device need
not exactly correspond to the distance between the commissures. The
device may be compressed or restrained to temporarily assume or
present its first shape, whereby the device assumes its second
shape when the restrain on the device is released. Alternatively,
the device may be transferred between two predetermined shapes.
[0014] The device provided for accomplishing the geometrical shape
change may be applied to the heart valve so as not to interfere
with the blood flow through the heart valve. The device may be
placed in abutment with heart valve tissue along substantially the
entire length of the device. This implies that the device may over
time grow into the valve tissue, whereby the device does not
present any surface of foreign material that may cause blood clot
forming. In order to grow into the valve tissue, the device may not
need to initially abut valve tissue over its entire length.
However, major parts of the device would need to abut valve tissue
and parts which do not abut the valve tissue should be placed in
close proximity to valve tissue such as to eventually grow into the
valve tissue.
[0015] Further, the device is arranged to abut valve tissue
throughout a cycle of heart action. This implies that the device,
if grown into valve tissue, would not impair the movement of the
leaflets during heart action.
[0016] There are several conceivable shapes of the device that
fulfil the requirement of abutting valve tissue along substantially
the entire length of the device throughout a cycle of heart action.
A person skilled in the art will however understand that the device
in its second shape should primarily abut valve tissue of the
annulus or close to the annulus, since the movements of the heart
valve are smallest there. Several different embodiments for
achieving the abutment between the device and valve tissue will be
presented below.
[0017] As used herein, the term "commissure" implies a site of
junction between leaflets of a heart valve.
[0018] The device may be arranged for establishing contact with the
heart valve such that a transfer from the first shape to the second
shape accomplishes a change of shape of the heart valve. The device
is therefore arranged for the heart valve to be attached or secured
to the device so that the device, when transferring from the first
shape to the second shape, will bring the heart valve with it to
change the shape of the heart valve.
[0019] The device may further comprise fixating means for attaching
the device to valve tissue. The fixating means may be arranged for
attaching the device to valve tissue before the transfer of shapes
of the device occurs. This fixes the valve tissue to the device,
whereby the valve tissue will follow the shape change of the
device.
[0020] The fixating means may be e.g. barbs or hooks arranged
extending from the device so as to engage with valve tissue.
[0021] The fixating means may be arranged at the contact points of
the device. This implies that the device may be attached to the
commissures of the heart valve and that the Change of distance
between the contact points will change the distance between the
commissures.
[0022] The device may be hook-shaped at the contact points for
providing the fixating means. These hooks may engage the both upper
and lower sides of the leaflets at the commissures so as to hook on
the device to the leaflets.
[0023] Alternatively, the device may comprise a portion arranged
for receiving a fixating means for attaching the device to valve
tissue. The device may be attached to valve tissue by means of e.g.
clips or sutures.
[0024] The portion for receiving a fixating means may be arranged
at the contact points of the device. This implies that the device
may be attached to the commissures of the heart valve and that the
change of distance between the contact points will change the
distance between the commissures.
[0025] The device may have an elongate part between the first and
second contact points. The form of an elongate part may easily be
adapted to the form of the heart valve such that the elongate part
may be arranged in abutment with valve tissue in the second shape
of the device.
[0026] The elongate part may, in the second shape of the device,
have a form that corresponds to at least a part of the annulus.
Thus, the device may be arranged in the heart valve such that the
elongate part abuts against a part of the annulus, which is
stationary during a cycle of heart action.
[0027] The device may be angled at the contact point for enabling
abutment with the valve tissue throughout a cycle of heart action.
The contact point is to be placed in contact with a commissure of
the heart valve, that is in the opening of the heart valve.
Therefore, the device may need to be angled at the contact point
for being placed in abutment with valve tissue between the contact
points.
[0028] The elongate part in the second shape of the device may be
C-formed. A device with such a form may abut valve tissue of the
annulus or near the annulus when placed in the heart valve.
[0029] The elongate part of the device may have a wave-like form.
This implies that the device may be compressed in the first shape
by compressing the wave-like form of the device. The device may
then present an elastic force pushing the device to assume its
second shape by extending the wave-like form.
[0030] The device may be ring-formed. This implies that the device
may be arranged in the heart valve to mainly engage the annulus or
valve tissue in close proximity of the annulus.
[0031] The device may exhibit an inherent force for transferring
the device from said first shape to said second shape. This implies
that the device itself may provide the transfer of shapes when
inserted to the heart valve.
[0032] The device may be formed to exhibit a spring force for
transferring the device from said first shape to said second shape.
Thus, the device may be compressed for bringing it to the first
shape and will assume the second shape when a compressing force is
released.
[0033] The device may be made of a shape memory material for
providing the inherent force. The shape memory may be activated
when the device has been inserted to the heart valve, e.g. by
heating the device to a predetermined temperature.
[0034] The invention also provides a method for improving the
function of a heart valve comprised of valve tissue including an
annulus, leaflets and at least a first and a second commissure
between adjacent leaflets. The method comprises inserting a device
in a first shape into the heart valve establishing contact between
a first contact point of the device and valve tissue at said first
commissure and a second contact point of the device and valve
tissue at said second commissure, causing a transfer of shape of
the first device from said first shape to a second shape such that
a distance between the first and second contact point of the device
is increased and, consequently, a distance between the first and
second commissures of the heart valve is increased, and arranging
the device in its second shape in the heart valve such that it
along substantially its entire length abuts the valve tissue
throughout a cycle of heart action.
[0035] Thanks to the invention, a geometrical shape change of the
heart valve is accomplished by stretching the distance between
commissures of the heart valve. This implies that the opening in
the heart valve between the commissures is stretched and that
mid-portions of the leaflets are brought closer together, whereby
the ability of the heart valve to close properly is improved.
[0036] The method may further comprise fixating the device in the
contact points to the commissures. This implies that the device is
attached to the commissures such that the transfer of shape of the
device certainly will bring the valve tissue with it to cause the
geometrical shape change of the heart valve.
[0037] The method may further comprise restraining the device in
its first shape during the inserting of the device into the heart
valve. This implies that the device is prohibited from assuming its
second shape during inserting of the device. Hereby, the device is
brought to the heart valve in the first shape in which the device
fits between the commissures of the heart valve.
[0038] The causing of the transfer of shape of the device may
comprise releasing a restrain on the device. The device may exhibit
an inherent force, which will cause the transfer of shape when a
restrain is released.
[0039] The causing of the transfer of shape of the device may
comprise activating a shape memory of the device. When a shape
memory is activated, the device will strive towards assuming its
second shape. The shape memory may be activated by e.g. heating the
device to a transition temperature.
BRIEF DESCRIPTION OF DRAWINGS
[0040] The invention will now be described in further detail by way
of example under reference to the accompanying drawings, on
which:
[0041] FIG. 1 is a schematical view of a cross section of the left
ventricle of the heart.
[0042] FIGS. 2A-2B are schematical views of a mitral valve of the
heart shown in an open and closed state, respectively.
[0043] FIG. 3 is a schematical view of a diseased mitral valve.
[0044] FIGS. 4A-4B are schematical views of the mitral valve
indicating the shape of the mitral valve before and after being
treated.
[0045] FIGS. 5A-5G are schematical views of different embodiments
of a device according to the invention.
[0046] FIGS. 6A-6B are schematical views of a first embodiment of
the device being applied to the mitral valve in a first and second
shape of the device, respectively.
[0047] FIGS. 6C-6D are schematical views of a second embodiment of
the device being applied to the mitral valve in a first and second
shape of the device, respectively.
[0048] FIGS. 7, 8A-8B and 9A-9B are schematical views of a heart
illustrating a method for applying a device according to the
invention to the mitral valve.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
[0049] Referring now to FIGS. 1 through 2B, the function of the
mitral valve 18 of the heart 12 will be described. The mitral valve
18 is situated between the left atrium and the left ventricle 14 of
the heart. The mitral valve 18 includes an annulus 20 and a pair of
leaflets 22, 24 which selectively allow and prevent blood flow into
left ventricle 14. The leaflets 22, 24 are supported for coaptation
by chordae tendinae or chords 26, 28 extending upwardly from
respective papillary muscles 30, 32. Blood enters left ventricle 14
through mitral valve 18 and is expelled during subsequent
contraction of heart 12 through aortic valve 34. As shown in FIG.
2A, the leaflets 22, 24 are drawn apart extending into the left
ventricle 14 for opening the mitral valve 18 and allowing passage
of blood into the left ventricle 14. As shown in FIG. 2B, the
leaflets 22, 24 make contact to seal the mitral valve 18 in order
to prevent blood transport from the left ventricle 14 back into the
left atrium.
[0050] The mitral valve has an anterior leaflet 22 and a posterior
leaflet 24. The leaflets 22, 24 are joined at commissures 36, 38
and the mitral valve 18 has an opening 40 between the commissures
36, 38. The anterior leaflet 22 is larger than the posterior
leaflet 24, whereby the opening 40 of the mitral valve 18 has an
arcuate shape. The opening 40 is opened and closed by movement of
the leaflets 22, 24. The movement is mainly performed by free edges
42, 44 of the leaflets 22, 24 between the commissures 36, 38.
[0051] In FIG. 3, a diseased mitral valve 18 is shown. The leaflets
22, 24 are not able to coapt properly, whereby the opening 40 in
the valve 18 is not completely closed. Blood will now leak through
the opening 40 backwards from the left ventricle 14 into the left
atrium. This implies that the function of the heart 12 is reduced,
since blood flows backwards through the system instead of being
pumped out to the aorta. Therefore, there will be a need for
ensuring that the leaflets 22, 24 are able to close the valve 18
properly.
[0052] Referring now to FIGS. 4A-4B, the principle of treating a
diseased mitral valve 18 with a device according to the invention
will be described. FIG. 4A shows a mitral valve 18 with an opening
40 which has not been completely closed due to inability of the
leaflets 22, 24 to coapt properly. Arrows A indicate a force to be
applied to the valve 18 in order to remodel the valve 18 such that
the leaflets 22, 24 are to be able to close properly. As shown in
FIG. 4A, the valve is remodeled by drawing the commissures 36, 38,
i.e. the sites of junction between the leaflets 22, 24, apart. This
implies that the mitral valve opening 40 is stretched and that the
free edges 42, 44 of the leaflets 22, 24 are brought closer
together. Hereby, the leaflets 22, 24 are able to close the valve
18 preventing leakage.
[0053] Even though the description is made with regard to the
mitral valve, it will be appreciated that the present invention is
applicable to any other valve with two leaflets or to valves with
three leaflets as well.
[0054] Referring now to FIGS. 5A-5G, embodiments of a device 50
according to the invention for treating a diseased mitral valve 18
will be described. The device is to be inserted in the mitral valve
18 to make contact with the commissures 36, 38. When contact is
established between the device 50 and the commissures 36, 38, the
device 50 will undergo a transfer of shape in order to bring the
valve tissue with it and perform remodeling of the valve 18 as
described above with reference to FIGS. 4A-4B.
[0055] As shown in FIGS. 5A-5G, the device 50 comprises a first
contact point 52 and a second contact point 54, which are to make
contact with valve tissue at the commissures 36, 38, respectively.
The device 50 may be hook-shaped at the contact points 52, 54,
whereby the device 50 may establish contact on both sides of the
leaflets 22, 24 at the commissures 36, 38. The device 50 may at the
contact points 52, 54 further comprise barbs or spikes or any
pointed protrusion (not shown), which may penetrate into valve
tissue for fixating the device 50 to the valve tissue.
Alternatively, the device 50 may be arranged for being fixed by
sutures or clips to the valve tissue.
[0056] When implanted, the entire device 50 should make contact
with the valve tissue in order to enable the device 50 growing into
the valve tissue. This implies that the device 50 will not exhibit
a surface of foreign material to the blood flow and thereby blood
clotting is prevented. To this end, the device 50 may have an
elongate part 56, as shown in FIGS. 5A-5F, between the contact
points 52, 54. The elongate part 56 may be arranged extending along
valve tissue over its entire length, whereby the device 50
eventually may be fully grown into valve tissue. The device 50
should make contact with valve tissue throughout a cycle of heart
action. Since the leaflets 22, 24 move during heart action for
opening and closing the mitral valve 18, the elongate part 56 is
preferably placed in contact with the annulus 20 or with leaflet
tissue close to the annulus 20. The device 50 is bent at the
contact points 52, 54 such that the elongate part may extend in a
plane substantially perpendicular to a plane in which the
hook-shape extend. This implies that the elongate part 56 of the
device 50 may extend along valve tissue in a plane of the annulus
20 of the mitral valve 18 while the contact points 52, 54 are
arranged in contact with the commissures 36, 38 of the mitral valve
18. Alternatively, the elongate part 56 may be fixed to contact
portions of the device 50 such that the elongate part 56 may extend
in the plane of the annulus 20.
[0057] The elongate part 56 may extend in numerous different ways
between the contact points 52, 54, as shown in FIGS. 5A-5F. The
elongate part 56 is to be placed in contact with the valve tissue
between the commissures 36, 38. As shown in FIGS. 2-4, the opening
40 of the mitral valve 18 has an arcuate shape. Therefore, the
elongate part 56 may be in contact with valve tissue even if it
extends essentially along a straight line between the commissures
36, 38. However, if the elongate part 56 has an arcuate or curved
shape, it may be placed in contact with valve tissue closer to the
annulus 20, which tissue undergoes less movement during heart
action. Therefore, the elongate part 56 may be bent as shown in
[0058] FIG. 5A, C-shaped as shown in FIGS. 5B and 5F, or slightly
arcuate as shown in FIGS. 5C and 5E. However, the elongate part may
have a wave-like form as shown in FIG. 5D extending along the
anterior leaflet 22 of the mitral valve 18.
[0059] As shown in FIG. 5G, the device may alternatively be
ring-formed to extend mainly along the annulus 20 of the mitral
valve 18. The ring-form deviates from the shape of the annulus 20
at the commissures 36, 38 for allowing contact between the device
50 and the commissures 36, 38.
[0060] As shown in FIGS. 6A and 6C, the device 50 is inserted to
the mitral valve 18 in a first shape. The device 50 is arranged in
the first shape to establish the contact between the device 50 and
the commissures 36, 38. The device 50 may then transfer to a second
shape for remodeling the mitral valve 18, as shown in FIGS. 6B and
6D. The elongate part 56 changes form between the first and second
shapes of the device 50. The elongate part 56 becomes less arcuate
or curved in order to push the contact points 52, 54 further apart
and thereby stretch the opening 40 of the mitral valve 18 such that
the free edges 42, 44 of the leaflets 22, 24 are brought closer
together.
[0061] Even though the device 50 is shown in FIGS. 6A-D placed on
the atrial side of the mitral valve 18, it should be understood
that the device 50 may alternatively be placed on the ventricular
side of the valve 18. The device 50 may then be placed in contact
with the chords 26, 28 such that the device 50 abuts the
ventricular side of the valve 18 and may grow into the valve
tissue.
[0062] The device 50 may be resilient such that, when deformed into
a first shape, it has an internal strive towards assuming the
second shape. The device 50 may then be restrained by an outer
force for keeping it in the first shape during insertion of the
device 50 between the commissures 36, 38 of the heart valve. The
restrain on the device 50 may be arranged to bend the elongate part
56 or compress the elongate part 56 such that the contact points
52, 54 are brought closer together. The device 50 may be made of a
fairly rigid material, such that the resilience of the device 50
will restore the shape of the device 50 in order to remodel the
mitral valve 18 when a restrain on the device 50 is released.
However, the device 50 may be slightly flexible in its second shape
to allow small movements of the annulus 20 and commissures 36, 38
during heart action while still keeping the commissures 36, 38
stretched apart in the remodeled shape. The device may be made of
any suitable medical grade material(s), such as medical grade
metals or plastics.
[0063] Alternatively, the device 50 may be made of a shape memory
material. The device 50 may then be inserted into the mitral valve
18 in a martensitic state, wherein the device is relatively soft
and may be easily deformed. Thus, the device 50 may in the
martensitic state easily be inserted into contact with the
commissures 36, 38 of the mitral valve 18. When the device is
heated above a transition temperature, the device 50 transforms
into an austenitic state and assumes a programmed shape. Thus, the
device 50 has an inherent strive towards assuming the second shape
and maintains its desired shape. The device may be made of a shape
memory alloy, such as Nitinol, or a shape memory polymer.
[0064] Typically, the distance between the contact points of the
device in its first shape is 18-20 mm, which corresponds to a
normal distance between the commissures of the mitral valve. The
transfer of shape of the device may typically create a 40% increase
in the distance between the contact points for remodeling the
mitral valve.
[0065] A method for treating a heart valve by means of the device
will now be described. The device may be implanted in the heart by
means of open surgery. The device is brought into the mitral valve
18 and placed in contact with the commissures 36, 38. The device
may be inserted to the mitral valve 18 through the apex of the
heart 12, as illustrated in FIG. 7. The device 50 may during
insertion be restrained in the first shape e.g. by pressing the
elongate part 56 to bend the elongate part 56 or by a restrain wire
extending between different portions of the elongate part 56
keeping these portions at a maximum distance from each other.
Alternatively, the device 50 is held in its first shape by means of
holding a temperature below a transition temperature for preventing
the device 50 from assuming its second shape.
[0066] When the device 50 has been placed in contact with the
commissures 36, 38, the device 50 is fixed to the valve tissue.
This may be accomplished by attaching portions of the device 50 to
the valve tissue by means of e.g. suturing or applying one or more
clips to the device and valve tissue. Alternatively, fixating means
are arranged on the device 50 and penetrate into valve tissue for
fixing the device 50 to the valve tissue.
[0067] When the device 50 has been securely fixed to the valve
tissue, the device 50 is allowed to transfer from its first to its
second shape. Thus, a restrain is released by e.g. releasing a
pressing force on the elongate part 56 or cutting a restrain wire.
Alternatively, the device 50 may be heated for assuming an
austenitic state and thereby transforming into its programmed,
second shape. When assuming its second shape, the device 50 will
cause a remodeling of the mitral valve 18 such that the opening 40
of the mitral valve 18 takes a form that may be properly closed by
the leaflets 22, 24.
[0068] Referring now to FIGS. 8A-8B and 9A-9B, a catheter-based
method for inserting the device 50 will be described. The device 50
is inserted by means of a catheter 60 into the heart 12. The
catheter 60 is entered into the body through the femoral artery 62
in the groin or the subclavian artery 64 in the arm of the patient
and is guided into the heart 12 retrograde through the artery and
through the aortic valve 34 into the left ventricle 14, as shown in
FIG. 8A. Alternatively, the catheter 60 may be guided through vena
cava into the right atrium 66 and may penetrate the interatrial
septum 68 to reach the left atrium 70, as shown in FIG. 8B.
[0069] The device 50 may be arranged in the catheter 60 on a distal
end of a carrier 72 and be covered by a restraining sheath 7 4, as
shown in FIG. 9A. When the catheter 60 has been inserted to the
mitral valve 18, the carrier 72 may be pushed partially out of the
restraining sheath 74, as shown in FIG. 9B. Thus, the contact
points 52, 54 of the device 50 may establish contact with the
commissures 36, 38. Thereafter, the carrier 72 may be completely
pushed out of the restraining sheath 74 for allowing the device 50
to assume its second shape and remodel the mitral valve 18. Then,
the device 50 may be released from the carrier 72 and the catheter
60 may be withdrawn from the body leaving the device 50 in place in
the mitral valve 18.
[0070] It should be emphasized that the embodiments described
herein are in no way limiting and that many alternative embodiments
are possible within the scope of protection defined by the appended
claims.
* * * * *