U.S. patent application number 16/486501 was filed with the patent office on 2019-11-28 for artificial heart valve.
The applicant listed for this patent is MITRAPEX, INC.. Invention is credited to Minoru TABATA.
Application Number | 20190358034 16/486501 |
Document ID | / |
Family ID | 68139475 |
Filed Date | 2019-11-28 |
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United States Patent
Application |
20190358034 |
Kind Code |
A1 |
TABATA; Minoru |
November 28, 2019 |
ARTIFICIAL HEART VALVE
Abstract
To provide an artificial heart valve capable of aiding the
functions of the mitral valve of a patient in a minimally invasive
manner. An artificial heart valve 1 which includes a valve leaflet
securing part 2 and valve leaflets (a first valve leaflet 5 and a
second valve leaflet 7), and in which the valve leaflets are
connected to the valve leaflet securing part 2 at the top portion
of the artificial heart valve 1, the valve leaflets each have a
region which narrows in width toward the bottom of the leaflet, and
the artificial heart valve is an artificial mitral valve or an
artificial tricuspid valve.
Inventors: |
TABATA; Minoru; (Tokyo,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MITRAPEX, INC. |
Tokyo |
|
JP |
|
|
Family ID: |
68139475 |
Appl. No.: |
16/486501 |
Filed: |
February 16, 2018 |
PCT Filed: |
February 16, 2018 |
PCT NO: |
PCT/JP2018/005444 |
371 Date: |
August 16, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61F 2220/0075 20130101;
A61F 2/2436 20130101; A61F 2/2469 20130101; A61F 2220/0016
20130101; A61F 2/2412 20130101; A61F 2/2415 20130101; A61F 2/2418
20130101; A61F 2220/0008 20130101; A61F 2/24 20130101; A61F
2230/0067 20130101 |
International
Class: |
A61F 2/24 20060101
A61F002/24 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 17, 2017 |
JP |
2017-027391 |
Jun 8, 2017 |
JP |
2017-113165 |
Dec 25, 2017 |
JP |
2017-247166 |
Claims
1. An artificial heart valve (1) which assists function of a mitral
valve or a tricuspid valve and comprises a ring (3), a first valve
leaflet (5), and a second valve leaflet (7), wherein the first
valve leaflet (5) and the second valve leaflet (7) are connected to
the ring (3) at an upper part of the artificial heart valve (1),
wherein the first valve leaflet (5) and the second valve leaflet
(7) are connected at a lower part junction (9) existing at a lower
part of the artificial heart valve (1), and wherein the first valve
leaflet (5) and the second valve leaflet (7) have, at a lower part
of the ring (3), portion which become narrower in width toward the
bottom thereof, and have a shape which is the narrowest in width at
a lower end thereof.
2. An artificial heart valve according to claim 1, wherein an upper
part of the first valve leaflet (5) and an upper part of the second
valve leaflet (7) are connected at an upper part junction (11).
3. An artificial heart valve according to claim 1, wherein the
first valve leaflet (5) or the second valve leaflet (7) is
connected, when the circumference of the ring (3) is assumed as
100%, at portions in which the circumference of the ring (3) is 30%
to 99%, both inclusive.
4. An artificial heart valve according to claim 1, wherein the ring
(3) can be folded, and can be opened within the left atrium or the
right atrium.
5. An artificial heart valve according to claim 1, wherein the ring
has an annular shape having a diameter of 30 mm to 60 mm, both
inclusive.
6. An artificial heart valve according to claim 1, wherein either
one of the ring (3), the first valve leaflet (5) and the second
valve leaflet (7) comprise a anchoring portion (13) for anchoring
it to a left atrial wall or a right atrial wall.
7. An artificial heart valve according to claim 6, wherein the
anchoring portion (13) is an adhering portion or portions to a left
atrial wall or a right atrial wall, which is or are provided at
either one of the first valve leaflet (5) and the second valve
leaflet (7) or at the both valve leaflets.
8. An artificial heart valve (1) comprising a valve leaflet
securing portion (2), and at least one valve leaflet (4), wherein
the valve leaflet (4) is connected to the valve securing part (2)
at an upper part of the artificial heart valve (1), wherein the
valve leaflet (4) has a part (47) which becomes narrower in width
toward the bottom thereof, and wherein the artificial heart valve
is an artificial mitral valve or an artificial tricuspid valve.
9. An artificial heart valve according to claim 8, wherein the
valve leaflet securing portion (2) is (i) a ring (3), or (ii) a
securing end (14) attached to the valve leaflet (4).
10. An artificial heart valve according to claim 8, wherein the
valve leaflet securing part (2) is provided with means for
preventing the artificial mitral valve or the artificial tricuspid
valve from passing therethrough.
11. An artificial heart valve according to claim 8, wherein the
valve leaflet comprises a first valve leaflet (5), and a second
valve leaflet (7), wherein the first valve leaflet (5) and the
second valve leaflet (7) are connected to the valve leaflet
securing portion (2) at an upper part of the artificial heart valve
(1), wherein the first valve leaflet (5) and the second valve
leaflet (7) are connected at a lower part junction (9) existing at
a lower part of the artificial heart valve (1), wherein the first
valve leaflet (5) and the second valve leaflet (7) have portions
which become narrower in width toward the bottom thereof, and
wherein the artificial heart valve is an artificial mitral valve or
an artificial tricuspid valve.
12. An artificial heart valve according to claim 11, comprising an
apical junction (10) in contact with a ventricular apex at the
lower part junction (9) or below the lower part junction (9).
13. An artificial heart valve according to claim 11, wherein the
valve leaflet securing part (2) is (i) a ring (3), or (ii) a first
securing end (6) and a second securing end (7) which are
respectively attached to an upper part of the first valve leaflet
(5) and an upper part of the second valve leaflet (7).
14. An artificial heart valve according to claim 11, wherein either
one of the valve leaflet securing part (2), the first valve leaflet
(5) and the second valve leaflet (7) comprises a anchoring portion
(13) for anchoring it to an atrial wall or an atrioventricular
valve annulus.
15. An artificial heart valve according to claim 14, wherein the
anchoring portion (13) is an adhering portion to the atrial wall or
the atrioventricular valve annulus, which is or are provided at
either one of the first valve leaflet (5) and the second valve
leaflet (7) or at the both valve leaflets.
16. An artificial heart valve according to claim 8, further
comprising, in either valve leaflet, a securing part (75) for
connecting the valve leaflet and a ventricular wall or a papillary
muscle.
17. An artificial heart valve according to claim 11, further
comprising, in either valve leaflet, a securing part (75) for
connecting the valve leaflet and a ventricular wall or a papillary
muscle.
Description
TECHNICAL FIELD
[0001] The present invention relates to an artificial heart valve.
More specifically, the present invention relates to an artificial
heart valve for medical use provided in the vicinity of mitral
valve or in the vicinity of the tricuspid valve to assist the
function of the mitral valve or the tricuspid valve.
BACKGROUND TECHNOLOGY
[0002] Mitral valve regurgitation or inefficiency is a disease in
which closing function of the mitral valve is impaired so that a
portion of blood ejected from the left ventricle into the aorta is
caused to flow in backward direction into left atrium. For example,
the functional mitral regurgitation (FMR) of the mitral valve
inefficiency is a disease in which blood regurgitation takes place
due to impared function or deformation of the left ventricle or the
left atrium, etc. although the mitral valve itself is normal.
[0003] In, e.g., the Japanese Patent No. 5392539 publication,
stainless artificial mitral valve and artificial heart valve
leaflets are described for the purpose of treating mitral valve
regurgitation. This artificial mitral valve is sutured to the
annulus of the heart (paragraph [0032] of this document). Namely,
this artificial mitral valve is a surgically implanted artificial
mitral valve, and it is implanted with opening the chest and using
a cardiopulmonary bypass machine. Such open heart surgery is large
burden on the patient, and usually requires a long time until
recovery.
[0004] On the other hand, in USP No. 2012-179244 specification, an
artificial mitral valve using stent is described. Such artificial
mitral valve using transcatheter approach and stent is less
invasive as compared to surgically implanted artificial mitral
valve. On one hand, with stented artificial mitral valve described
in this publication, the mitral valve of the patient himself
becomes unfunctional although native mitral valve itself with
functional mitral valve regurgitation (FMR) is normal. On the
contrary, mitral valve of patients in which such stented artificial
mitral valve is implanted is a nuisance, and can obstruct the left
ventricular outflow tract.
[0005] The tricuspid valve is a valve located between the right
atrium and the right ventricle of the heart. The tricuspid valve
has a function to prevent backflow of blood. In regard to such
tricuspid valve, there is a disease such as tricuspid valve
inefficiency (tricuspid regurgitation)
[0006] In JP-A 2016-28762, an artificial heart valve (artificial
mitral valve or artificial tricuspid valve) using stent is
described. Also with respect to such artificial heart valve, native
heart valve itself becomes unfunctional. For this reason, when such
artificial valve using stent is implanted, the interaction with the
left ventricular contraction that the original mitral valve has may
be lost, leading to lowering in the cardiac function.
PRIOR ART
Patent Document
[0007] Patent Document 1: Japanese Patent No. 5392539 publication
Patent Document 2: U.S. Patent 2012-179244 specification
Patent Document 3: JP A2016-28762
SUMMARY OF THE INVENTION
Problems that the Invention Intends to Solve
[0008] The present invention has an object to provide an artificial
heart valve which is capable of assisting, in a minimally invasive
manner, the function of the mitral valve and/or the tricuspid valve
of patients.
Means for Solving the Problems
[0009] The present invention relates to an artificial valve 1
(artificial heart valve) comprising a ring 3, a first valve leaflet
5, and a second valve leaflet 7.
[0010] The first valve leaflet 5 and the second valve leaflet 7 are
connected to the ring 3 at an upper part of the artificial valve
1.
[0011] The first valve leaflet 5 and the second valve leaflet 7 are
connected to a lower part junction 9 existing at a lower part of
the artificial valve 1.
[0012] The first valve leaflet 5 and the second valve leaflet 7
have, at a lower part of the ring 3, portions which become narrower
in width toward the bottom thereof. Further, it is preferable that
the valve leaflet has a shape which is narrowest in width at the
lower end thereof.
[0013] This artificial valve functions as an artificial valve which
assists the function of the mitral valve or the tricuspid
valve.
[0014] It is preferable that this artificial valve is preferably
such that an upper part of the first valve leaflet 5 and an upper
part of the second valve leaflet 7 are connected at an upper part
junction 11.
[0015] This artificial valve is preferably such that when the
circumference of the ring 3 is assumed to be 100%, the first valve
leaflet 5 or the second valve leaflet 7 is connected at portions of
30% to 99% both inclusive of the circumference of the ring 3.
[0016] This artificial valve is preferably such that the ring 3 can
be folded, and can be opened within the left atrium or the right
atrium.
[0017] It is preferable that the ring has an annular shape having a
diameter of 30 mm to 60 mm both inclusive.
[0018] It is preferable that either of the ring 3, the first valve
leaflet 5 and the second valve leaflet 7 has an anchoring portion
13 for anchoring it to the left atrial wall or the right atrial
wall. The anchoring portion 13 may be adapted to be held to the
right atrial wall.
[0019] This artificial valve may be preferably such that the
anchoring portion 13 is an adhering portion or portions to the left
atrial wall or the right atrial wall, which is or are provided at
either one of the first valve leaflet 5 and the second valve
leaflet 7 or at the both valve leaflets. The anchoring portion 13
may be an adhering portion to the right atrial wall.
[0020] The above-mentioned problems can be also solved by an
artificial heart valve described below. This artificial heart valve
is an artificial heart valve 1 comprises a valve leaflet securing
part 2, and at least one valve leaflet 4. The artificial heart
valve is an artificial mitral valve or an artificial tricuspid
valve. The valve leaflet 4 is connected to the valve leaflet
securing part 2 at an upper part of the artificial heart valve 1.
An example of the valve leaflet securing part 2 is ring 3 or
securing end (band) 14. The valve leaflet 4 has a portion 47 which
becomes narrower in width toward the bottom thereof. The
combination of the type of artificial heart valves and the valve
leaflet securing part 2 may be arbitrary. For example, the
artificial valve may be artificial mitral valve, the valve leaflet
securing part 2 may be ring 3, and any other combination except
therefor may be adopted. The artificial heart valve may comprise
means for preventing the artificial mitral valve or the artificial
tricuspid valve from passing therethrough. An example of the
passage preventing means may be a anchoring portion which will be
described later.
[0021] The valve leaflet securing part 2 is
[0022] (i) a ring 3, or
[0023] (ii) a securing end 14 attached to the valve leaflet 4.
[0024] Another embodiment different from the above-mentioned
artificial heart valve which can solve the above-mentioned problems
is an artificial heart valve 1 comprising valve leaflet securing
part 2, first valve leaflet 5 and second valve leaflet 7.
[0025] The first valve leaflet 5 and the second valve leaflet 7 are
connected to the valve securing part 2 at an upper part of the
artificial heart valve 1.
[0026] The first valve leaflet 5 and the second valve leaflet 7 are
connected at a lower part junction 9 existing at a lower part of
the artificial heart valve 1.
[0027] The first valve leaflet 5 and the second valve leaflet 7
have portions which become narrower in width toward the bottom
thereof.
[0028] Moreover, the first valve leaflet 5 and the second valve
leaflet 7 may have a shape which is the narrowest in width at the
lower part junction 9 or below the lower part junction 9.
[0029] The artificial heart valve is the artificial mitral valve or
the artificial tricuspid valve. More specifically, an example of
the valve leaflet securing part 2 is ring 3, first securing end 6
and second securing end 7. The combination of the type of
artificial heart valves and the valve leaflet securing part 2 are
arbitrary. For example, the artificial heart valve may be an
artificial mitral valve, and the valve securing part 2 may be ring
3, and combinations except therefor may be adopted.
[0030] A preferred example of the artificial heart valve comprises
an apical junction 10 in contact with the ventricular apex (of the
right ventricle or the left ventricle) at the lower part junction 9
or below the lower part junction 9.
[0031] The valve leaflet securing part 2 is
[0032] (i) a ring 3, or
[0033] (ii) a first securing end 6 and a second securing end 7
which are respectively attached to the upper part of the first
valve leaflet 5 and the upper part of the second valve leaflet 7.
The first securing portion 6 and the second securing portion 7 may
be respectively curved, or may be respectively straight. Further,
the first securing end 6 and the second securing end 7 may be
respectively changeable in shape (flexible).
[0034] Either one of the valve leaflet securing part 2, the first
valve leaflet 5 and the second valve leaflet 7 may comprise a
anchoring portion 13 for anchoring it to the atrial wall. The
anchoring portion 13 may be an adhering portion or portions to the
atrial wall, which is or are provided at either one of the first
valve leaflet 5 and the second valve leaflet 7 or at the both valve
leaflets.
[0035] The anchoring portion may be held or adhere to the atrial
wall or the atrioventricular valve annulus.
[0036] In addition, either valve leaflet (in the case of an
artificial heart valve having a single valve leaflet, that valve
leaflet, and in the case of an artificial heart valve having two
valve leaflets, single or two valve leaflets) may further comprise
a securing part 75 for connecting the valve leaflet and a
ventricular wall or a papillary muscles.
Effects and Advantages with the Invention
[0037] The present invention can provide an artificial heart valve
capable of assisting, in a minimally invasive manner, the function
of the mitral valve or the tricuspid valve of patient.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] FIG. 1 is a conceptual diagram illustrating an example of an
artificial heart valve according to the present invention.
[0039] FIG. 2 is a conceptual diagram illustrating an example of an
artificial heart valve according to the present invention.
[0040] FIG. 3 is a conceptual diagram for explaining organs around
the heart.
[0041] FIG. 4 is a conceptual diagram illustrating a use example of
the artificial heart valve according to the present invention.
[0042] FIG. 5 is a conceptual diagram illustrating an example of an
artificial heart valve according to the present invention having a
securing end.
[0043] FIG. 6 is a conceptual diagram illustrating an example of an
artificial heart valve according to the present invention having a
securing end.
[0044] FIG. 7 is a conceptual diagram illustrating an artificial
tricuspid valve (artificial valve assisting the function of the
tricuspid valve).
[0045] FIG. 8 is a conceptual diagram illustrating an example of an
artificial heart valve comprised of a single valve leaflet.
[0046] FIG. 9 is a conceptual diagram illustrating an example of an
artificial heart valve comprised of a single valve leaflet.
[0047] FIG. 10 is a conceptual diagram illustrating an example of
an artificial heart valve having a thread like structure.
BEST MODE FOR CARRYING OUT THE INVENTION
[0048] Preferred embodiments for carrying out the present invention
will now be described with reference to the attached drawings. It
should be noted that the present invention is not limited to
embodiments as described below, but comprises an embodiment or
embodiments that those persons skilled in the art have modified as
occasion demands within a self-explanatory range from such
embodiment or embodiments.
[0049] FIG. 1 is a conceptual diagram illustrating an example of an
artificial heart valve according to the present invention. FIG.
1(a) illustrates an outside diagram. FIG. 1(b) illustrates a
conceptual diagram of a first valve leaflet. FIG. 1(c) illustrates
a conceptual diagram of a second valve leaflet. An example
illustrated in FIG. 1 is such that the valve leaflet securing
portion 2 is ring 3, and is used for the mitral valve. The valve
leaflet securing portion 2 is secured to the valve leaflets so as
to permit the first valve leaflet and the second valve leaflet to
continuously locate above the heart valve (within the atria).
Moreover, the valve leaflet securing part 2 may be continuously
disposed suitably within the atria as the result that it is
connected to the atrial wall. For example, since the ring has a
diameter larger than that of the heart valve, the situation where
it moves toward ventricular side can be prevented.
[0050] The artificial heart valve 1 according to the present
invention illustrated in FIG. 1 comprises the ring 3, the first
valve leaflet 5, and the second valve leaflet 7. The first valve
leaflet 5 and the second valve leaflet 7 may have the same shape,
or may have shapes different from each other. Further, the first
valve leaflet 5 and the second valve leaflet 7 are connected to the
ring 3 at the upper part of the artificial heart valve 1. The first
valve leaflet 5 and the second valve leaflet 7 may be such that the
upper end or the region in the vicinity of the upper end (e.g., the
region of 0.1 mm to 10 mm both inclusive from the upper end) may be
sewn to the ring 3. The first valve leaflet 5 and the second valve
leaflet 7 are connected at a lower part junction 9 of the
artificial heart valve existing at the lower part of the artificial
heart valve 1. Moreover, the first valve leaflet 5 and the second
valve leaflet 7 have shape portions which become narrower in width
toward the bottom thereof. The lower part junction 9 may be lower
ends of the first valve leaflet 5 and the second valve leaflet 7,
or may be located within the region in the vicinity of the lower
end (e.g., the region which is of 0.1 mm to 10 mm both inclusive
from the lower end). Further, the first valve leaflet 5 and the
second valve leaflet 7 may have a shape which is the narrowest in
width at the lower end. Further, the first valve leaflet 5 and the
second valve leaflet 7 have a shape which is the narrowest in width
at the lower end thereof. Further, the first valve leaflet 5 and
the second valve leaflet 7 may be broader in width than that of the
lower part junction 9 at their lower ends thereof. In addition, it
is preferable that either one of the first valve leaflet 5 and the
second valve leaflet 7 or the both valve leaflets has or have a
shape which is the narrowest in width at the lower end or ends
thereof.
[0051] The ring 3 has an annular shape having a diameter, e.g., of
30 mm to 60 mm both inclusive (or 35 mm to 55 mm both inclusive, 40
mm to 50 mm both inclusive). The ring 3 may have an elliptical
shape or a circular shape so as to adapt to the shape of the left
atrium (or the right atrium). It is preferable that the ring 3 is
manufactured by bio-adaptive material. The ring may comprise metal
(spring) so that it can be folded and can be deployed, or may be
resin material. An example of the ring made of resin is a ring made
of silicon as the resin.
[0052] An example of the thickness (diameter) of the ring is 1 mm
to 20 mm both inclusive, and may be 5 mm to 15 mm both inclusive,
may be 1 mm to 5 mm both inclusive, and may be 8 mm to 12 mm both
inclusive. Particularly, in the case of an artificial heart valve
comprising a single valve leaflet, it is preferable to employ a
ring having a relatively larger thickness.
[0053] For the first valve leaflet 5 and the second valve leaflet
7, known materials used in the artificial heart valve may be used.
An example of materials for the valve leaflet is membrane derived
from human stem cells, and tissue derived from mammals (e.g., pigs,
cows, horses). As another example of material for valve cusp,
tissue derived from the patient may be used. As tissue derived from
the patient, there may be adopted a tissue reproduced by using
bio-tissue material collected from the patient. The bio-tissue
substance is a substance necessary for forming bio-derived
material. An example of the bio-tissue material is fibroblasts,
smoothing muscle cells, endothelial cells, stem cells, animal cells
such as ES cells and/or iPS cells, etc., various kinds of proteins
(collagen, elastin), saccharides such as hyaluronic acid, etc.,
cell growth factors, and cytokine. By placing base material for
forming artificial heart valve under the environment where
bio-tissue substance exists, it is possible to form processable
connective tissue body on the surface of the base material for
forming the artificial heart valve. Another example of material for
the valve leaflet is resin or plastics.
[0054] This artificial heart valve has a shape such that the lower
ends of the first valve leaflet 5 and the second valve leaflet 7
are narrow in width. For this reason, this artificial heart valve
is inserted from the left ventricle (or the right ventricle) to
open the ring at the left atrium (or the right atrium) thereafter
to permit the lower ends of the first valve leaflet 5 and the
second valve leaflet 7 to be implanted into the portion of the left
ventricle or the left ventricular apex 53 into which the artificial
heart valve has been inserted. Therefore, this artificial heart
valve will be stable within the heart of patients. Namely, it is
preferable that the artificial heart valve according to the present
invention has a size such that the end portion of the artificial
heart valve arrives at the left ventricular apex, or a length in
which it is beyond the left ventricular apex when the ring is
located within the left atrium (or the right atrium). Namely, this
artificial heart valve is preferably an artificial heart valve for
assisting the mitral valve, and is an artificial heart valve in
which the ring stays within the left atrium (or the right atrium),
and the lower part of the valve leaflet of the artificial heart
valve arrives at the left ventricular apex to secure the lower end
of the valve leaflet of the artificial heart valve is secured to
the left ventricular apex after the length of the artificial heart
valve is adjusted.
[0055] It is preferable that, when connected to the valve leaflet
securing part 2 as the artificial heart valve, these valve leaflets
5 and 7 have shapes in which the portion in contact with the valve
leaflet securing part 2 is the broadest in width, and which is
unchanged in width toward the bottom thereof from the portion in
contact with the valve leaflet securing part 2, or which becomes
narrower in width toward the bottom thereof. To the contrary, these
valve leaflets 5 and 7 may have a shape comprising a portion which
is gently swollen in width on the way toward the bottom thereof.
Even in the case of valve leaflets 5 and 7 having a shape which
becomes broader in width on the way, it is preferable that those
valve leaflets have a width which is narrower than that of the
portion in contact with the valve leaflet securing part 2. It is
preferable that the first valve leaflet 5 and the second valve
leaflet 7 are connected at least at the lower part junction 9. It
is preferable that the lower part junction 9 is provided at the
lower part of the valve leaflet.
[0056] The first valve leaflet 5 illustrated in FIG. 1(b) will now
be described. This valve leaflet is such that width W1 of an upper
end 21 which is a portion sewn to the ring 3 is, for example, 30 mm
to 90 mm both inclusive. The width W1 may be 40 mm to 80 mm both
inclusive, and may be 45 mm to 70 mm both inclusive. The first
valve leaflet is preferably such that when the circumference of the
ring 3 is assumed to be 100%, the portion of 15% to 45% both
inclusive of the circumference of the ring is coated (or is
connected at that portion), and may be such that the portion of 20%
to 40% both inclusive is coated and may be such that the portion of
20% to 30% both inclusive is coated. The valve leaflet 5
illustrated in FIG. 1(b) is such that a portion uniform in width
exists on the upper portion thereof. This portion is a junction 25
to the second valve leaflet 2. An example of the length (height) of
this portion 25 is 1 mm to 10 mm both inclusive, and may be 2 mm to
8 mm both inclusive, and may be 4 mm to is 8 mm both inclusive. In
this example, there exists a portion 27 which becomes narrower in
width in a curved manner from the upper part constant in width
toward the lower end 23. An example of the width of the lower end
23 is 2 mm to 20 mm both inclusive, and may be 3 mm to 10 mm both
inclusive, and may be 3 mm to 5 mm both inclusive. The height L1 of
the first valve leaflet 5 is 20 mm to 70 mm both inclusive, and may
be 25 mm to 65 mm both inclusive, may be 30 mm to 40 mm both
inclusive, may be 40 mm to 70 mm both inclusive, and may be 40 mm
to 60 mm both inclusive. The concrete size of the valve leaflet may
be designed by taking into account, e.g., the shape of the heart of
patients, the degree of blood regurgitation and the state of
disease. The shape portion which becomes narrower in width toward
the bottom thereof may be equal to the entirety of the height L1 of
the first valve leaflet 5, and may be 30% to 100% both inclusive,
may be 50% to 100% both inclusive, may be 70% to 100% both
inclusive, may be 80% to 100% both inclusive, and may be 90% to
100% both inclusive. The upper limit of the shape portion which
becomes narrower in width toward the bottom may be 99%, 98%, 97%,
95%, 91% in place of 100%. Moreover, the valve leaflet may have,
e.g., a shape which is not changed in width from the upper end of
the valve leaflet until the middle way thereof, or becomes narrower
in width toward the bottom thereof. Further, the valve leaflet may
have a shape which is not changed in width from the upper end
thereof until the middle way thereof, or becomes narrower in width
toward the bottom thereof, and further has a portion which becomes
broader in width at the lower end portion thereof. The shape
portion which becomes narrower in width toward the bottom thereof
also similarly applies to other valve leaflets in this
specification.
[0057] The second valve leaflet 7 illustrated in FIG. 1(c) may be
manufactured fundamentally in a manner similar to the first valve
leaflet 5. On one hand, the second valve leaflet may be thicker
than the first valve leaflet. By doing so, a difference in rigidity
between these valve leaflets will generate, thus making it possible
to effectively prevent blood regurgitation. When the average
thickness of the first valve leaflet is designated at d.sub.1, and
the thickness of the second valve leaflet is designated at d.sub.2,
d.sub.1 and d.sub.2 may be equal to each other. On the other hand,
when thicknesses of these two valve leaflets are different from
each other, there may hold
1.01d.sub.1.ltoreq.d.sub.2.ltoreq.3d.sub.1, there may hold
1.05d.sub.1.ltoreq.d.sub.2.ltoreq.2.5d.sub.1, there may hold
1.5d.sub.1.ltoreq.d.sub.2.ltoreq.2.5d.sub.1, and there may hold
1.75d.sub.1.ltoreq.d.sub.2.ltoreq.2.5d.sub.1. L3 illustrated in
FIG. 1(c) may be to the same degree as that of L1 in FIG. 1(b).
Moreover, the lower end 33 of the second valve leaflet may be a
width to the same degree as that of the lower end 23 of the first
valve leaflet. The upper part 31 of the second valve leaflet is
such that a gentle convex part (projected part) 31 exists in a
manner to fit the shape of the ring. Further, a junction 35 which
is a portion constant in width exists at the upper part of the
second valve leaflet. This portion may be sutured into the
connecting portion 25 of the first valve leaflet. In this example,
there exists a portion 37 which becomes narrower in width in a
curved manner from the upper part which is constant in width toward
the lower end 33.
[0058] This artificial heart valve may be such that the upper part
of the first valve leaflet 5 and the upper part of the second valve
leaflet 7 are connected at the upper part junction 11 of the
artificial heart valve 1. In that case, since those two valve
leaflets are connected, the stability of the valve leaflets will be
enhanced. Further, this artificial heart valve is such that the
lower portions of the first valve leaflets and the second valve
leaflets are connected at the lower part junction 9. Thus, the
portion between these junctions can be swollen or contracted. By
such operation, this artificial heart valve can prevent blood
regurgitation.
[0059] It is preferable that this artificial heart valve is such
that the ring 3 can be folded and can be opened within the left
atrium (or the right atrium). When this artificial heart valve has
such property, it can be inserted into the heart and can be placed
there within in a transcatheter manner. For this reason, the open
heart surgery becomes unnecessary in order to place the artificial
heart valve.
[0060] Also for the ring 3, it is preferable to employ a ring with
such a supporting rod (or thread like member) to connect ends of
the circle. The supporting rod may be formed by means of thread
bridging over the diameter or the edge portions of the ring.
Provision of such a supporting rod can maintain the shape of the
ring, thus to effectively prevent the situation in which the valve
leaflet deviates toward the atrial side.
[0061] This artificial heart valve is preferably such that either
one of the ring 3, the first valve leaflet 5 and the second valve
leaflet 7 is provided with a anchoring portion 13 for anchoring it
to the left atrial wall (or the right atrial wall). The anchoring
portion 13 may be an adhering portion to the left atrial wall (or
the right atrial wall) provided at either one of the first valve
leaflet 5 and the second valve leaflet 7 or at the both valve
leaflets. Since such anchoring portion 13 is provided, there is no
necessity for such artificial heart valve to secure to the left
atrium (or the right atrium) by suturing.
[0062] The anchoring portion may be held or adhere to the atrial
wall or the atrioventricular valve annulus. The anchoring method is
similar to the above. An example of the anchoring method may
provide sewing to a tissue to be held, and/or may biologically
adhere (tissues or tissue and element adhere to each other). The
valve annulus generally refers to the root portion of the valve.
The atrioventricular valve refers to either one of the mitral valve
and the tricuspid valve, or both valves.
[0063] An example of the anchoring portion 13 as illustrated in
FIG. 1 is a plurality of hooks provided at the outer circumference
of the ring 3. This hook is hooked to the left atrium (or the right
atrium), thus preventing the ring 3 from being fluctuated within
the left atrium (or the right atrium). The anchoring portion 13 may
be a plurality of very small projections provided on the ring 3.
Since too large projections damages the atrium, an example of the
length (height) of the projection is 0.1 mm to 5 mm both inclusive,
and may be 0.2 mm to 3 mm both inclusive, and may be 0.2 mm to 1 mm
both inclusive. Such projections may be manufactured by any
biocompatible substance. Such projections may comprise a coating
layer on the surface thereof. The coating layer may comprise, e.g.,
trehalose and various chemicals. Moreover, the coating layer may
comprise any substance which secretes adhering substance such as
fibrin, etc. or adhering substance in-vivo so that the ring or the
valve leaflet upper part and the left atrium (or the right atrium)
adhere to each other. When the first valve leaflet 5 or the second
valve leaflet 7 comprises an adhering portion, the valve leaflet
may comprise, e.g., a plurality of uneven portions or a plurality
of projections provided, e.g., at the upper portion thereof (e.g.,
a region within 20 mm from a portion connected to the ring 3, or a
region within 15 mm therefrom). In addition, such valve leaflet may
comprise an adhesion induced layer which is manufactured by
adhering material is applied on the upper part of the valve
leaflet.
[0064] Another example of the anchoring portion 13 is a fold
provided at the outer circumference of the ring. When this fold is
viewed from the upper surface, for example, it has an annular
shape, wherein the inner circumferential portion of this fold is
connected to the ring. This fold has a shape in which a portion
having a shape of a triangular wave comprising mountain portions
and valley portions which are continuous to each other surrounds
the inner circumferential portion. The width of the annular portion
may be adjusted as occasion demands, and may be 0.1 mm to 20 mm
both inclusive, may be 0.5 mm to 10 mm both inclusive, and may be 1
mm to 5 mm both inclusive.
[0065] FIG. 2 is a conceptual diagram illustrating an example of
the artificial
heart valve according to the present invention. FIG. 2(a)
illustrates an outside diagram. FIG. 2(b) illustrates a conceptual
diagram of the first valve leaflet. FIG. 2(c) illustrates a
conceptual diagram of the second valve leaflet. As illustrated in
FIG. 2, the artificial heart valve according to the present
invention is not required to cover the ring with the first and
second valve leaflets. In the artificial heart valve, the region
where the first valve leaflet 5 and the second valve leaflet 7 are
connected to the ring 3 may be a region of 30% to 99% both
inclusive (or a region 35% to 90% both inclusive) of the ring 3.
The artificial heart valve of the above-mentioned patent document 1
(the Japanese Patent No. 5392539 publication) is adapted so that
the region which is about one half of the ring is covered with two
valve leaflets. In this example, as illustrated in FIG. 2(a), when
assembled as an artificial heart valve, any portion which is
constant in width does not exist in the first valve leaflet (FIG.
2(b)) and the second valve leaflet (FIG. 2(c)), although their
widths become narrower from the upper end toward the lower end with
respect to the portion to be connected to the ring 3, a plurality
of inflection points exist in that curve. Namely, as the shape of
the valve leaflet, there may be adopted not only valve leaflets
which uniformly become narrower, but also valve leaflets which
become broader on the way toward the lower end and valve leaflets
which are remarkably uneven.
[0066] An example of a method of manufacturing an artificial heart
valve according to the present invention will now be described.
FIG. 3 is a conceptual diagram for explaining organs around the
heart. Arrows in the figure indicate directions of blood flow. The
artificial valve heart according to the present invention serves to
fundamentally assist the function of the mitral valve 51. First of
all, information such as sizes of a heart of the patient, the state
of muscle 53 constituting the left ventricle, the shapes of the
left ventricle 55 and the left atrium 57, and/or the stage of the
mitral valve blood regurgitation (the function of the mitral valve)
are collected. Further, when it is determined to use the artificial
heart valve according to the present invention, the material and
the sizes of the artificial heart valve are then determined. A
reproductive medicine is performed in dependency upon the material
of the membrane of the valve leaflet thus to provide a material for
the membrane. The valve leaflet is then cut out from the membrane.
Thereafter, processing is implemented to the valve leaflet as
occasion demands. Further, the upper part of the valve leaflet is
sewn to the ring. On the other hand, the lower portions of the
valve leaflet are sewn to each other. In this way, an artificial
heart valve is provided. This example is an example of a method of
manufacturing the artificial heart valve, and e.g., artificial
heart valves or valve membranes of several sizes may be prepared in
advance to assemble them in correspondence with patients.
[0067] FIG. 4 is a conceptual diagram illustrating a use example of
the artificial heart valve according to the present invention. In
this example, the left small thoracotomy approach is performed
under the general anesthesia. The artificial heart valve is
contained into a sheath (container) 61 in the folded state, and is
conveyed to a portion in the vicinity of the left ventricle through
blood vessel. Further, the sheath 61 is penetrated through the left
ventricular apex 53, and is passed between the anterior valve
leaflet and the posterior valve leaflet of the mitral valve through
the left ventricle 55, whereby such sheath is reached into the left
atrium. In the state where the artificial heart valve exists within
the left atrium, the sheath 61 is withdrawn therefrom. Thus, the
ring is deployed within the left atrium. Thereafter, the alignment
between the mitral valve of the patient and the artificial heart
valve is made by using the echo-guide, and the anchoring portion
(hook) 13 is secured to the left atrial wall. The lower end of the
artificial heart valve is caused to be situated outside of the left
ventricular apex 53, and the length of the artificial heart valve
is adjusted while observing the junction of the artificial heart
valve by means of echo. After the length is determined in this way,
the valve leaflet is secured to the left ventricular apex 53. The
artificial heart valve is thus placed so as to overlie the
patient's own valve. By doing so, the patient's own valve of the
patient will be also activated in a manner as before. In addition,
the continuity to the left ventricular wall is maintained in both
the patient's own valve and the artificial heart valve.
[0068] Also in this example, it is preferable that the artificial
heart valve is in contact with or is secured to the valve cusp of
the left ventricle. For example, by securing the end of the
artificial heart valve by means of clip, etc. at the outside of the
left ventricle, it is possible to maintain the shape of the
artificial heart valve within the heart.
[0069] An artificial heart valve comprising the valve leaflet
securing portion 2 as the ring 3, and used for tricuspid valve will
now be described. An artificial heart valve for tricuspid valve may
be adjusted as occasion demands in correspondence with sizes of the
valve and also be prepared in a manner similar to the artificial
heart valve for mitral valve, and the ring 3 may be placed within
the atrium, further the lower part of the valve leaflet is placed
within the left ventricle. It is to be noted that the artificial
heart valve according to the present invention assists the function
of the tricuspid valve and is effective for treatment of the
tricuspid valve regurgitation.
[0070] The case where the valve leaflet securing part 2 is a first
securing end 6 and a second securing end 8 which are respectively
attached to the upper part of the first valve leaflet 5 and the
upper part of the second valve leaflet 7 will now be described.
[0071] The valve leaflet securing part 2 is an element for
preventing the valve leaflet upper portion existing within the
atrium from moving into the ventricle. Ordinarily, the valve
leaflet securing part 2 is larger than (e.g., longer than) the
space of the cardiac valve (mitral valve, or tricuspid valve). FIG.
5 is a diagram illustrating an example of an artificial heart valve
having a securing end. The securing portions 6 and 8 serving as the
first and second securing ends 6 and 8, which are respectively
attached to the upper portion of the first valve leaflet 5 and the
upper portion of the second valve leaflet 7, may be a rod in which
the curved shape is approximately constant, or a straight rod. In
spite of these shapes, it is preferable that the securing ends 6, 8
have a hardness higher than the valve leaflets 5, 7. An example of
the lengths of these securing ends 6, 8 are 10 mm to 90 mm both
inclusive. The lengths of these securing ends 6, 8 may be 20 mm to
less than 90 mm, may be larger than 40 mm and less than 80 mm, and
may be 45 mm to 70 mm both inclusive. It is preferable that the
first securing end 6 and the second securing end 8 respectively
have lengths of the upper part of the valve leaflet 5 and the upper
part of the second valve leaflet 7, or respectively have lengths
longer than the upper part of the first valve leaflet 5 and the
upper part of the second valve leaflet 7.
[0072] An example of the thickness (maximum diameter) of the
securing end is 1 mm to 20 mm both inclusive, and may be 5 mm to 15
mm both inclusive, may be 1 mm to 5 mm both inclusive, and may be 8
mm to 12 mm both inclusive. Particularly in the case of a single
valve leaflet, a valve leaflet having a relatively thick securing
end is preferable. In addition, the securing end may be provided
with the above-mentioned anchoring portion.
[0073] FIG. 5 is a conceptual diagram illustrating an example of an
artificial heart valve according to the present invention having a
securing end. FIG. 5(a) illustrates an outside diagram of the
artificial heart valve. FIG. 5 (b) illustrates a conceptual diagram
of the first valve leaflet. FIG. 2 (c) illustrates a conceptual
diagram of the second valve leaflet. In the example illustrated in
FIG. 5, first securing end 6 is attached on the upper part of the
first valve leaflet 5. On one hand, a second securing end 8 is
provided on the upper part of the second valve leaflet 7. In the
example illustrated in FIG. 5, it is preferable that those securing
ends 6 and 8 of the artificial heart valve are larger (longer) than
the space within the valve that the artificial heart valve forms so
that these securing ends 6, 8 are stably located within the atrium,
and are not moved into the ventricles. Nevertheless, these securing
ends 6, 8 are preferably secured to the left atrial wall or the
right atrial wall by means of the anchoring portion. For this
reason, the lengths of the securing ends 6, 8 may be shorter than
the valve port. The anchoring portion may employ, as occasion
demands, the anchoring portion which has been previously described,
and may be such that these securing ends 6, 8 are cased to adhere
to the atrial wall to form adhering portion so that the securing
ends 6, 8 are stably located within the atrium. On the other hand,
in the example illustrated in FIG. 5(a), both ends of the first
securing end 6 and the second securing end 8 are respectively
connected to mating both ends by means of supporting rods 12. This
supporting rod 12 is an arbitrary element, and is not necessarily
required to exist. It is preferable that the supporting rod has
rigidity and malleability. The spacing between these two securing
ends 6, 8 is kept constant (or, these two securing ends 6, 8 are
maintained so as to provide an arrangement having a predetermined
spacing or more) by means of the supporting rod 12.
[0074] FIG. 6 is a conceptual diagram illustrating an example of an
artificial heart valve according to the present invention having a
securing end. For example, also when the artificial heart valve is
the artificial tricuspid valve, in a manner similar to the
artificial heart valve illustrated in FIG. 4, an artificial
tricuspid valve may be inserted in a tricuspid valve direction from
the right ventricular apex of the right ventricle and the valve
leaflet securing portion 2 is opened in the state where the folded
valve leaflet securing part 2 (the ring 3, or the securing ends 6,
8) is located within the right atrium to place the valve leaflet
securing part 2 so that the valve leaflet securing part 2
continuously exist. Further, in this instance, the lower end of the
artificial heart valve (artificial tricuspid valve) may be sutured
to the right ventricular apex, or may be allowed to be drawn toward
the outside of the heart from the right ventricular apex.
[0075] It is to be noted that, in connection with the artificial
mitral valve, it is sufficient to move, as illustrated in FIG. 4,
an artificial heart valve in the state where the valve leaflet
securing portion 2 is folded to the left ventricle through the left
atrium via the femoral vein, the jugular vein, the superior vena
cava, or the inferior vena cava, and to guide it until a location
in which the lower end of the artificial heart valve has been
penetrated through the outside of the heart from within the left
ventricle, the left ventricular apex of the left ventricle, or the
left ventricular apex. Further, also in either case, in the state
where the valve leaflet securing part is located within the left
atrium, the valve leaflet securing part 2 is opened. Thus, the
valve leaflet securing part 2 is disposed so that the valve leaflet
securing part 2 continuously exists within the left atrium. In this
way, the artificial mitral valve can be disposed, at a location to
assist the function of the mitral valve, within the left ventricle
and the left atrium. Further, the lower end of the artificial heart
valve may be secured to the left ventricular apex by suturing the
lower end of the artificial heart valve to the left ventricular
apex, etc. By performing similar work also with respect to the
artificial tricuspid valve, the artificial tricuspid valve can be
disposed at a location to assist the function of the tricuspid
valve (within the right ventricle and the right atrium).
[0076] FIG. 7 is a conceptual diagram illustrating an example in
which the artificial heart valve according to the present invention
having a securing part functions as an artificial tricuspid valve
(an artificial valve to assist the function of the tricuspid
valve). In this example, two securing ends are contained within the
ventricle. Moreover, the lower end of the artificial tricuspid
valve exists through the ventricular apex (may be secured to the
ventricular apex later). Further, the portion with which the
ventricular apex is in contact of the artificial tricuspid valve
constitutes an apical junction.
[0077] An artificial heart valve comprised of a single valve
leaflet 4 will now be described. The artificial heart valve
comprised of a single valve leaflet 4 is fundamentally connected to
the patient's own valve leaflet to thereby prevent blood
regurgitation. Accordingly, it is preferable that this artificial
heart valve may be connected to the patient's own valve leaflet. It
is preferable that this heart valve is also connected (secured) to
the ventricle by means of the ventricular apex anchoring portion.
Thus, a situation such that the artificial heart valve moves toward
the atrial side can be prevented. FIG. 8 is a conceptual diagram
illustrating an example of an artificial heart valve comprised of a
single heart valve leaflet. FIG. 8(a) illustrates an outside
diagram of the artificial heart valve. FIG. 8(b) illustrates an
outside diagram of the valve leaflet 4. FIG. 8(c) is a diagram
illustrating an example of an artificial valve having supporting
rods. The example illustrated in FIG. 8 is the artificial heart
valve in which the number of valve leaflets 4 is one, and the valve
leaflet securing part 2 is comprised of the ring. The ring and the
valve leaflet have been already described. Nevertheless, preferred
sizes of a valve leaflet when constituted with a single valve
leaflet will be described on the basis of FIG. 1(b), they are given
as below. A width W1 of upper end 21 which is a portion to be sewn
to the ring 3 is, for example, 30 mm to 90 mm both inclusive. The
width W1 may be 40 mm to 80 mm both inclusive, and may be 45 mm to
70 mm both inclusive. The valve leaflet is preferably such that
when the circumference of the ring 3 is assumed as 100%, the
portion of 15% to 45% both inclusive of the circumference of the
ring is coated (or is connected at that portion), and may be such
that the portion of 20% to 40% both inclusive is coated and may be
such that the portion of 20% to 30% both inclusive is coated. The
valve leaflet illustrated in FIG. 1(b) is such that a portion
uniform in width exists at the upper part thereof. An example of
the length (height) of this portion 25 is 1 mm to 10 mm both
inclusive, and may be 2 mm to 8 mm both inclusive and may be 4 mm
to 8 mm both inclusive. In this example, there exists a portion 27
which becomes narrower in width in a curved manner from the upper
part which is constant in width toward the lower end 23 thereof. An
example of the width of the lower end 23 is 2 mm to 20 mm both
inclusive, and may be 3 mm to 10 mm both inclusive and may be 3 mm
to 5 mm both inclusive. The height L1 of the valve leaflet is 20 mm
to 70 mm both inclusive, and may be 25 mm to 65 mm both inclusive,
may be 30 mm to 40 mm both inclusive, may be 40 mm to 70 mm both
inclusive, and may be 40 mm to 60 mm both inclusive. Concrete sizes
of the valve leaflet may be designed by taking into consideration,
for example, the shape of the heart, the degree of blood
regurgitation, and the state of disease of patients.
[0078] The artificial heart valve according to the present
invention may be used in the treatment using the surgical operation
in addition to the catheter approach (e.g., transapical approach
and the transvenous approach). When the artificial heart valve is
the mitral valve, either the catheter approach such as the
transapical approach and the transvenous approach or the approach
based on the surgical operation may be used. Also, when the
artificial heart valve is the tricuspid valve, either the catheter
approach such as the transapical approach and the transvenous
approach or the approach based on the surgical operation may be
used. The valve leaflet securing part 2 is secured to the valve
leaflet 4 so that the valve leaflet 4 is continuously located above
the heart valve (within the atrium). In addition, the valve leaflet
securing part 2 may be connected to the atrial wall so that it is
stably and continuously placed within the atrium.
[0079] FIG. 9 is a conceptual diagram illustrating an example of an
artificial heart valve comprised of a single valve leaflet. In this
example, the valve leaflet securing part 2 is formed with the
securing end. For example, the length of the securing end may be
allowed to be larger than that of the heart valve, thereby making
it possible to prevent the heart valve from being moved toward the
ventricular side. The securing end 14 may be, e.g., curved
rod-shaped securing end, or may be linearly elongated rod-shaped.
Moreover, it is preferable that the securing end 14 has a hardness
higher than that of the valve leaflet 4. For the curved rod-shaped
securing end, there may be employed a securing end comprising an
arcuated rod-shaped portion, and a thread portion which connects to
the rod-shaped tip. It is preferable that the securing end 14 may
be manufactured by biocompatible material. An example of the length
of the securing end 14 is 10 mm to 150 mm both inclusive. The
length of the securing end 14 may be 20 mm to 120 mm both
inclusive, may be 40 mm to 100 mm both inclusive and may be 45 mm
to 90 mm both inclusive. The thickness of the securing end 14 may
be 0.1 mm to 3 mm both inclusive, may be 0.3 mm to 2 mm both
inclusive and may be 0.5 mm to 1 mm both inclusive,
[0080] The valve leaflet 4 illustrated in FIG. 9(a) may be
fundamentally manufactured in a manner similar to the first valve
leaflet 5 and the second valve leaflet 7 which have been described
with reference to FIG. 1. As illustrated in FIG. 9(b), the valve
leaflet has a shape capable of connecting to the artificial valve,
and a shape which is formed to be broadest in width at the upper
part of the artificial valve, smoothly becomes narrower in width
until the middle thereof, smoothly becomes broader in width from a
portion located below the artificial valve, and becomes narrower in
the middle arriving at the lower end.
[0081] FIG. 10 is a conceptual diagram illustrating an example of
an artificial heart valve having a thread-like structure. FIG.
10(a) is a conceptual diagram illustrating an example of the
artificial heart valve comprising a thread like structure which
connects portions in the vicinity of both left and right ends of
the lower end of the valve leaflet, and an apical junction existing
at the lower end of the thread like structure. FIG. 10(b) is a
conceptual diagram illustrating an example of the artificial heart
valve comprising a cutout from the portion in the vicinity of the
central portion of the lower end of the valve leaflet toward the
valve leaflet upper part, and respectively comprising thread like
structures in the vicinity of both left and right ends of the lower
end of the valve leaflet. FIG. 10(c) is a conceptual diagram
illustrating an example of the artificial heart valve comprising an
apical junction at the lower end of the valve leaflet. FIG. 10
depicts, as an example of the valve leaflet securing part 2, an
artificial heart valve comprising securing end. However, there may
be employed an artificial heart valve comprising a valve leaflet
having a thread like structure, and a ring as the valve leaflet
securing part 2. Moreover, FIG. 10 depicts a single valve leaflet.
However, also in the artificial heart valve comprising two valve
leaflets, any thread like structure may be provided similarly to
FIG. 10. The thread like structure is, e.g., a portion narrow in
width (e.g., 0.1 mm to 2 mm both inclusive, 0.5 mm to 1 mm both
inclusive), which is attached to the valve leaflet. The thread like
structure may be manufactured by resin such as PTFE or
polypropylene, or may be manufactured by the same material as that
of the valve leaflet. As long as there may be employed such an
embodiment in which the thread like structure is connected to the
valve leaflet, or is connected to an object where the valve leaflet
is desired to be secured thus to ability to stabilize the valve
leaflet or to regulate flow of blood, the number of threads and/or
the shape thereof are not particularly limited.
[0082] FIG. 10(a) is a conceptual diagram illustrating an example
of an artificial heart valve comprising a thread like structure 71
which connects portions in the vicinity of both left and right ends
at the lower end of the valve leaflet, and an apical junction 73
existing at the lower end of the thread like structure. The apical
junction 73 is connected to the apex of the heart. Thus, the
artificial heart valve is stabilized. In this example, the thread
like structure extends from the center of the lower part of the
valve leaflet toward below the valve leaflet. Further, the thread
like structure 71 which connects portions in the vicinity of both
left and right ends of the lower end of the valve leaflet, and a
thread like structure 71 extending from the center of the lower
part of the valve leaflet toward below the valve leaflet are
connected, and are connected to the apical junction 73. By allowing
the valve leaflet near the apical junction 73 to be of the thread
like structure, mobility of the valve port is enhanced so that the
valve port area is increased.
[0083] FIG. 10(b) is a conceptual diagram illustrating an example
of an artificial heart valve comprising a cutout from the portion
in the vicinity of the center of the lower end of the valve leaflet
4 toward the valve leaflet upper part, and comprising thread like
structures 71 respectively in the vicinity of both left and right
ends of the lower end of the valve leaflet. At the tips of the
thread like structures 71 of this artificial heart valve, securing
parts 75 are respectively provided. These securing parts 75 are
respectively connected to the ventricular wall or the papillary
muscles. Thus, the valve leaflet will be connected to the
ventricular wall or the papillary muscles through the thread like
structures 71 so that the position of the artificial heart valve is
stabilized. It is to be noted that securing parts 75 are directly
provided at respective left and right portions of the lower end of
the valve leaflet.
[0084] FIG. 10(c) is a conceptual diagram illustrating an example
of an artificial heart valve comprising an apical junction at the
lower end of the valve leaflet. In this example, a thread like
structure extends from the lower end of the valve leaflet, and an
apical junction 73 is provided at the tip thereof. Also, in this
embodiment, a thread like structure 71 and a securing parts 75 at
the tip thereof may be provided on left and right side surfaces of
the valve leaflet. When the securing part is connected to the
thread like structure, a portion of the thread like structure may
be tied with an object portion. Moreover, the securing part may be
the thread like structure. In this case, for example, one end may
be secured to the valve leaflet by means of thread, and the other
end may be connected to the object portion (e.g., ventricular wall
or papillary muscle)
INDUSTRIAL APPLICABILITY
[0085] The present invention can be utilized in the field of
medical equipments.
DESCRIPTION OF REFERENCE NUMERALS
[0086] 1 Artificial heart valve [0087] 3 Ring [0088] 5 First valve
leaflet [0089] 7 Second valve leaflet [0090] 9 Lower part junction
[0091] 13 Anchoring portion
* * * * *