ARTIFICIAL HEART VALVE
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.
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 TECHNOLOGYMitral 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.
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.
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.
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)
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 DocumentPatent Document 1: Japanese Patent No. 5392539 publication
Patent Document 2: U.S. Patent 2012-179244 specification
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 ProblemsThe 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.
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.
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.
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.
This artificial valve functions as an artificial valve which assists the function of the mitral valve or the tricuspid valve.
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.
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.
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.
It is preferable that the ring has an annular shape having a diameter of 30 mm to 60 mm both inclusive.
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.
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.
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.
The valve leaflet securing part 2 is
(i) a ring 3, or
(ii) a securing end 14 attached to the valve leaflet 4.
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.
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.
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.
The first valve leaflet 5 and the second valve leaflet 7 have portions which become narrower in width toward the bottom thereof.
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.
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.
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.
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 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).
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.
The anchoring portion may be held or adhere to the atrial wall or the atrioventricular valve annulus.
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 InventionThe 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.
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.
The artificial heart valve 1 according to the present invention illustrated in
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.
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.
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.
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.
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.
The first valve leaflet 5 illustrated in
The second valve leaflet 7 illustrated in
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.
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.
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.
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.
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.
An example of the anchoring portion 13 as illustrated in
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.
heart valve according to the present invention.
An example of a method of manufacturing an artificial heart valve according to the present invention will now be described.
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.
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.
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.
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).
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.
It is to be noted that, in connection with the artificial mitral valve, it is sufficient to move, as illustrated in
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.
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.
The valve leaflet 4 illustrated in
The present invention can be utilized in the field of medical equipments.
DESCRIPTION OF REFERENCE NUMERALS
- 1 Artificial heart valve
- 3 Ring
- 5 First valve leaflet
- 7 Second valve leaflet
- 9 Lower part junction
- 13 Anchoring portion
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.
Type: Application
Filed: Feb 16, 2018
Publication Date: Nov 28, 2019
Inventor: Minoru TABATA (Tokyo)
Application Number: 16/486,501