Mechanical artificial heart valve

Abstract

The present invention relates to a mechanical prosthetic heart valve (10), which comprises: an annular support (12) having an inner peripheral wall (14) centered on a longitudinal axis (X) and defining an internal passage; and at least two movable leaflets (40), preferably three leaflets (40), arranged in such a way that each can effect a rotational movement about a rotational axis perpendicular to the longitudinal axis (X), so that the valve (10) can be transformed from a closed configuration to an open configuration and vice versa. Each leaflet comprises a central portion (46) and two lateral fins (48a, 48b) symmetrically located on either side of the central portion (46) with respect to the symmetry plane (Z) of the leaflet. Each fin (48a, 48b) comprises one of two end portions (49a, 49b). The annular support (12) comprises two opposite edges (26, 28) and as many extensions (30) as there are leaflets, the extensions (30) axially extending from one of the opposite edges (26, 28), and shaped recesses (32) are formed on two opposite sides of each extension (30), and when the valve (10) is transformed from an open configuration to a closed configuration, the recesses (32) serve as guiding surfaces for the respective end portions (48a, 48b) of each leaflet (40) and vice versa. The contact area of each leaflet (40) in the open position with the inner peripheral wall (14) is less than 15% of the total width of the leaflet (40) extending between the ends of the two end portions (49a, 49b).

Description

Technical Field

[0001] The present invention relates to a mechanical prosthetic heart valve. Background Art

[0002] There is a distinction between two major categories of prosthetic heart valves. One category encompasses valve prostheses made of flexible tissue disposed on rigid struts to mimic natural valves, known as tissue valves. The other category encompasses mechanical valve prostheses, which are devices independent of the shape of natural valves and made of wear-resistant and biocompatible artificial materials.

[0003] Due to their anatomical structure and physiological mode of operation, tissue valves offer biological performance similar to that of natural heart valves, as they conform to the natural structure of blood flow through the heart chambers and through the aorta.

[0004] This particular feature of tissue valves allows patients to be spared the need for anticoagulant therapy for the rest of their lives, and this eliminates the risk of bleeding accidents due to long-term administration of these drugs, and thus provides these patients with a better quality of life. In this way, the patient may forget that he has a heart valve implanted.

[0005] However, these tissue valves have a limited lifespan, as they inevitably become calcified over time, which means they need to be replaced on average after about ten years. Due to their limited lifespan, this type of prosthesis is in most cases intended for subjects over 65 years of age or subjects with a life expectancy shorter than the lifespan of the tissue valve.

[0006] Unlike tissue valves, mechanical artificial valve devices do not deteriorate and have a lifespan exceeding the human lifespan. Since the 1960s, several generations of mechanical heart valves have been designed. For example, one can mention valve prostheses composed of a caged ball (STARR-EDWARDS), then in the early 1970s, a second-generation prosthesis composed of a tilting disc (BJORK-SHILEY), and subsequently, ten years later, a third-generation prosthesis of the side-opening bileaflet type of the ST-JUDE MEDICAL brand was introduced.

[0007] EP1083845 discloses a mechanical prosthetic heart valve, comprising an annular support and three leaflets. Each leaflet includes two flanges cooperating with the annular support to allow the heart valve to pass from an open position to a closed position and vice versa. The annular support includes three pairs of lateral openings called windows. Each pair of windows is arranged corresponding to the flanges of the associated leaflet. The windows allow blood to flow to the rear of the flanges of each leaflet and flush most of the pivot areas of the leaflets in the open and closed positions. This flushing should help reduce blood stasis behind the flanges, thus reducing the likelihood of local blood clots or thrombi forming in this area. However, in-vivo tests in this particular configuration show that the downstream struts of the windows with the leaflets in the open position actually constitute an obstacle placed in the flow during systole. This obstacle is prone to promoting thrombus formation.

[0008] WO2008152224 discloses the latest generation of mechanical prosthetic heart valves. The heart valve includes an annular support, which includes an inner peripheral surface centered on a longitudinal axis and defining an internal passageway, and three leaflets arranged in such a way that each can effect a rotational movement about a rotational axis perpendicular to the longitudinal axis, such that the valve can be switched from a closed configuration to an open configuration and vice versa. When the valve is in the open configuration, the leaflets define a main orifice centered on the longitudinal axis therebetween, and blood can flow axially through the main orifice, while when the valve is in the closed configuration, the leaflets block the internal passageway of the annular support so as to be able to prevent blood from flowing back through the main orifice. Each leaflet includes: a leading edge designed to abut against a part of the inner peripheral surface of the annular support when the valve is in the closed configuration; a central part including an outer surface and an inner surface; and two lateral flanges symmetrically located on both sides of the central part and inclined with respect to the central part.

[0009] According to the configuration of the valve described herein, when the leaflets rotate to all positions, the leading edges of the two flanges of each leaflet remain very close to or in contact with the inner peripheral surface of the annular support. Now, this may result in the formation of a flow recirculation zone downstream of the flanges that is prone to promoting platelet aggregation. Therefore, patients may need to take anticoagulants to avoid any risk of thrombus formation. However, adhering to lifelong treatment is not easy, especially for young people, especially young women of childbearing age.

[0010] In addition, there may be a problem of leaflet wear due to the friction of the leading edges of the two flanges of each leaflet, which may have a significant impact on the lifespan of the valve.

[0011] Therefore, an object of the present invention is to propose a mechanical prosthetic heart valve that minimizes the platelet aggregation zone to avoid taking anticoagulants. Summary of the Invention

[0012] According to the present invention, this object is achieved by means of a mechanical prosthetic heart valve, which comprises an annular support having an inner peripheral wall centered on a longitudinal axis and defining an internal passage, and at least two movable leaflets, preferably three movable leaflets, arranged such that each can effect a rotational movement about a rotational axis perpendicular to said longitudinal axis, such that the valve can be switched from a closed configuration to an open configuration and vice versa. When the valve is in the open configuration, the leaflets define therebetween a main orifice centered on the longitudinal axis, and blood can flow axially through this main orifice. When the valve is in the closed configuration, the leaflets at least partially block the internal passage of the annular support so as to be able to prevent blood from flowing back through the main orifice. Each leaflet comprises a leading edge designed to abut a portion of the inner peripheral wall of said annular support when said valve is in the closed configuration, an inner surface extending from said leading edge and opposite to said inner surface and an outer surface extending from said leading edge, and two terminal portions. The annular support comprises two opposite edges and as many extensions as there are leaflets, which extend axially from one of the opposite edges. A middle forming recess is created on two opposite sides of each extension. When the prosthetic valve changes from the open configuration to the closed configuration, this recess serves as a guiding surface for these respective terminal portions of each leaflet and vice versa. The annular support also comprises two lower bearing members for each leaflet on the inner peripheral wall, which are located between two of said extensions and are designed to abut the corresponding leaflet adjacent when the valve is in the closed configuration.

[0013] The contact area of each leaflet with the inner peripheral wall in the open position is less than 15% of the total width of the leaflet extending between the ends of the two terminal portions.

[0014] In one embodiment, the contact area of each leaflet with the inner peripheral wall in the open position is less than 10% of the total width of the leaflet.

[0015] In one embodiment, the contact area of each leaflet with the inner peripheral wall in the open position is less than 7.5% of the total width of the leaflet.

[0016] In one embodiment, the contact area of each leaflet with the inner peripheral wall in the open position is less than 5% of the total width of the leaflet.

[0017] In one embodiment, each leaflet comprises a central portion and two lateral wings symmetrically located on either side of the central portion with respect to the plane of symmetry of the leaflet. Each lateral wing comprises an outer surface, an inner surface and one of the two terminal portions. When the heart valve is in the open configuration, two flow channels are respectively located between a lower bearing member and an adjacent extension of the annular support.

[0018] In one embodiment, the two flow channels are mainly defined by the inner peripheral wall of the annular support and the outer surfaces of the corresponding two lateral wings.

[0019] In one embodiment, the lateral wings are inclined relative to the central portion of each leaflet. The wings have respective first and second curved proximal portions extending from a central portion having a curved outer surface, and respective first and second distal portions that contact one and the other extensions of the annular support when the heart valve is in the open state. The first and second distal portions extend substantially parallel to the inner peripheral wall and are aligned with one and the other extensions respectively. The curved outer surfaces of each of the first and second proximal portions curve away from the inner peripheral wall and are located outside the one and the other extensions respectively in the open configuration.

[0020] In one embodiment, when the heart valve transitions from the closed configuration to the open configuration, the two flow channels are formed starting from the pivot of each leaflet. The dimensions of the two flow channels associated with each leaflet increase as the leaflet gradually pivots until the point where the valve is in the open configuration.

[0021] In one embodiment, the surface of the inner peripheral wall of the annular support is a continuous surface without windows at the level of the ends of each leaflet.

[0022] In one embodiment, when the heart valve is in the open configuration, the leading edge and the outer surface of each leaflet are at least 0.2 mm away from the inner peripheral wall over at least 75% of the total width of the leaflet.

[0023] In one embodiment, when the heart valve is in the open configuration, the leading edge and the outer surface of each leaflet are at least 0.5 mm away from the inner peripheral wall over at least 75% of the total width of the leaflet.

[0024] In one embodiment, when the heart valve is in the open configuration, the leading edge and the outer surface of each leaflet are at least 0.5 mm away from the inner peripheral wall over at least 90% of the total width of the leaflet.

[0025] In one embodiment, in a plane perpendicular to the longitudinal axis of the valve, the axis of rotation of each leaflet is located at a distance from the longitudinal axis that is greater than 75% of the radius of the annular support.

[0026] In one embodiment, the distance between the axis of rotation of each leaflet and the outer surface of the central portion of the leaflet is greater than 0.2 mm.

[0027] In one embodiment, the distance by which the outer surface of each leaflet in the open position is spaced from the inner peripheral wall of the annular support is at least equal to 5% of the diameter of the annular support at the plane of symmetry of the leaflet.

[0028] In one embodiment, any mechanical prosthetic heart valve includes three leaflets pivotally mounted between three extensions. When the valve is in the open configuration, six flow channels are formed. The flow channels are located near each side of each extension. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Examples of embodiments of the present invention are pointed out in the specification and illustrated by the drawings, in which:

[0030] - Figure 1 A perspective view of a mechanical prosthetic heart valve in an open configuration is illustrated, in which the leaflets define a main orifice through which blood can flow;

[0031] - Figure 2 A perspective view of a mechanical prosthetic heart valve in a closed configuration is illustrated, in which the leaflets block the internal passage of the annular support so as to prevent blood from flowing back through the main orifice;

[0032] - Figure 3 A view of Figure 1 as viewed from above is illustrated;

[0033] - Figure 4 A view of Figure 2 as viewed from above is illustrated;

[0034] - Figure 5 A view of Figure 4 is illustrated in a sectional view taken along A-A;

[0035] - Figure 6 A view of the annular support as viewed from above is illustrated;

[0036] - Figure 7 A view of Figure 6 is illustrated in a sectional view taken along B-B;

[0037] - Figure 8 A perspective view of the underside of a valve having only one leaflet is illustrated;

[0038] - Figure 9 A perspective view of the underside of the leaflet is illustrated;

[0039] - Figure 10 A view of Figure 6 showing an enlarged portion of the annular support is illustrated;

[0040] - Figure 11 A view of the leaflet as viewed from above from one side of its outer surface is illustrated;

[0041] - Figure 12 A view of Figure 11 is illustrated in a sectional view taken along C-C;

[0042] - Figure 13 Shows a partial perspective view of a mechanical prosthetic heart valve in a closed configuration, where the partial section is in the region of the lower support member associated with the leaflets;

[0043] - Figure 14 shows a view similar to that of a mechanical prosthetic heart valve according to the prior art Figure 13 ;

[0044] - Figure 15 Shows a view similar to that of Figure 13 when the mechanical prosthetic heart valve is in an open configuration;

[0045] - Figure 16 Shows a partial perspective view of a mechanical prosthetic heart valve in a closed configuration, where the partial section is in the region of the upper support member associated with the leaflets;

[0046] - Figure 17 Shows a view similar to that of Figure 16 when the mechanical prosthetic heart valve is in an open configuration;

[0047] - Figure 18 shows a view similar to that of a mechanical prosthetic heart valve according to the prior art Figure 17 ;

[0048] - Figure 19 Shows a partial perspective view of the mechanical prosthetic heart valve, where the leaflets are in both the closed and open configurations;

[0049] - Figure 20 shows a view similar to that of a mechanical prosthetic heart valve according to the prior art Figure 19 ;

[0050] - Figure 21 Shows a partial perspective view from below the mechanical prosthetic heart valve at the level of the flow channel;

[0051] - Figure 22 Shows a partial sectional view of the mechanical prosthetic heart valve in a plane perpendicular to the longitudinal axis of the annular support,

[0052] - Figure 23 shows a view similar to that of a mechanical prosthetic heart valve according to the prior art Figure 22 ;

[0053] - Figure 24 and 25 are respectively sectional views taken along A-A and B-B of Figure 22 to illustrate the forces applied to the leaflets when the valve is open, and

[0054] - Figures 26 and 27 are cross-sectional views taken along C-C and D-D of Figure 23, respectively, showing the forces applied to the leaflets of a mechanical prosthetic heart valve according to the prior art when it is open. DETAILED DESCRIPTION

[0055] As Figures 1 to 4 shown significantly, the mechanical prosthetic heart valve 10 includes an annular support member 12 that defines a central internal passageway 9 therein (see also Figure 6 ), for the flow of circulating blood under the action of cardiac systole. When the heart valve 10 is in the open position, the flow through the heart valve 10 is qualified as a forward flow, and its flow direction (also referred to herein as the outflow direction) is indicated by Figure 1 the arrow A in. Conversely, when the heart valve 10 is closed, the flow that flows in the opposite direction (also referred to herein as the inflow direction) is qualified as a retrograde flow.

[0056] The central internal passageway for blood flow is defined by the inner peripheral wall 14 of the annular support member 12 ( Figure 5 ), and the annular support member 12 serves as a support for three movable leaflets 40. As Figure 1 depicted, the annular support member 12 of the heart valve 10 is centered on a longitudinal axis X and exhibits rotational symmetry about this axis. It will be noted that, without affecting the principles of the present invention, the valve may include only two leaflets, in which case the annular support member 12 has an oval shape and the leaflets are oval in shape, or may include more than three leaflets.

[0057] The annular support member 12 also includes an outer peripheral wall 22 that exhibits a peripheral edge 24 that is intended to receive a suture ring (not depicted), which is made of, for example, fabric, and allows a surgeon to attach the valve to the heart tissue using sutures in a known manner.

[0058] In Figure 1 , 3 , the heart valve 10 is depicted in an open configuration, where the leaflets 40 are in a known raised or open position and blood flow passes through the valve in the outflow direction, while in Figure 2 , 4 , the valve is depicted in a closed configuration, where the leaflets are in a so-called lowered or closed position, thereby preventing blood from flowing through the heart valve 10 in the inflow direction.

[0059] As Figure 5As can be seen, the annular support 12 includes an upstream edge or leading edge 26 that connects the inner peripheral wall 14 to the outer peripheral wall 22 and is positioned on the upstream side of the anterograde flow. The annular support 12 also includes a downstream edge or trailing edge 28 that is located on the downstream side of the anterograde flow and likewise connects the inner peripheral wall 14 to the outer peripheral wall 22 of the annular support.

[0060] With particular reference Figure 6 and Figure 7 , the support 12 also includes three guide extensions 30 that extend from the trailing edge 28 in the outflow direction parallel to the longitudinal axis X. Thus, the guide extensions 30 form projections or serrated projections that extend axially relative to the trailing edge 28, and the width of their base is substantially the same as that of their tip (dimension perpendicular to the axis X). These guide extensions 30 receive and mold recesses 32 in the form of a rotating surface, and the end portions of the movable leaflets, which will be described later, cooperate with the molded recesses 32 such that the heart valve 10 can transition from a closed configuration to an open configuration and vice versa.

[0061] In particular reference Figure 11 , each leaflet 40 is the same as all other leaflets provided with the heart valve 10. The leaflet 40 includes a central portion 46 to which two lateral flanges 48a, 48b are connected, and the two lateral flanges 48a, 48b are symmetrically located on both sides of the central portion and are inclined relative to the central portion, as Figure 12 particularly visible in Figure 12 . The central portion 46 has an outer surface 46a and an inner surface 46b, each of which is substantially planar, although in one embodiment, the inner surface 46b and / or the outer surface 46a may be slightly curved (as shown by the inwardly curved inner surface 46b in Figure 12 ) to optimize flow characteristics.

[0062] The flanges 48a, 48b have an outer surface 47a and an inner surface 47b, and correspondingly have proximal portions 43a, 43b and distal portions 41a, 41b. The outer surface 47a of the distal portions 41a, 41b may be substantially planar or slightly curved. The proximal portions 43a, 43b are connected to the central portion 46 and form a gentle curve inward to the inner passage 9 such that the distal portions 41a, 41b form an angle relative to the central portion 46. In particular, the outer surface 47a of the distal portions 41a, 41b of the flanges 48a, 48b forms an angle relative to the outer surface 46a of the central portion 46, and in one embodiment, this angle may be between 45 degrees and 60 degrees. The leaflet 40 is symmetric about the symmetry plane Z. The leaflet 40 is rigid and may be formed of a rigid material such as PEEK.

[0063] Reference Figure 11, the leaflet 40 includes: a trailing point 45; two end portions 49a, 49b; a first trailing edge 44a extending between the trailing point 45 and the first end portion 49a; a second trailing edge 44b extending between the trailing point 45 and the second end portion 49b; and a curved leading edge 42 that extends between the first end portion 49a and the second end portion 49b within the width W of the leaflet 40. These elements together generally define a triangular shape with an elongated curved leading edge 42. The outer and inner surfaces 46a, 46b of the central portion 46 and the small wings 48a, 48b are located between the trailing point 45 and the end portions 49a, 49b and do not include the trailing point 45 and the end portions 49a, 49b. Note that the leading edge 42 (and the trailing edge 44) can be rounded, and the outer surface 46a and the inner surface 46b are defined as extending from those rounded edges.

[0064] When the leaflet is in the open position, as Figure 1 and 3 depicted in, the leading edge 42 is located on the upstream side of the antegrade flow, and in the closed position, this leading edge 42 mates with the inner wall 14 of the annular support 12 to form a seal that prevents blood flow through, as Figure 4 visible in. The leading edge 42 of the leaflet extends from the first end portion 49a to the second end portion 49b, and these portions are located at the distal ends of the respective lateral small wings 48a, 48b. The leading edge 42 is curved to match the curvature of the inner wall 14.

[0065] In addition, the leaflet 40 includes a trailing edge 44 on the side of the leaflet opposite to the side where the leading edge 42 is located and on the downstream side of the antegrade flow. The trailing edge 44 includes two symmetric portions 44a, 44b that extend from the lateral small wings 48a, 48b to the downstream end region where they meet to form a point 45. The point 45 is aligned with the symmetry plane Z of the leaflet.

[0066] The heart valve 10 also includes a number of lower (i.e., on the upstream side or the front side) support or supporting members that are different for each leaflet (each leaflet has its own supporting members 16a, 16b) and are formed on the inner peripheral wall 14 of the annular support 12. In particular, with particular reference to Figure 6 , two lower support or supporting members 16a, 16b (also referred to herein as lower support or lower supporting members) are arranged between two adjacent guiding extensions 30 to support each leaflet 40 when the heart valve 10 is in the closed configuration. The lower supporting members 16a, 16b are positioned on the upstream side of the leaflet 40 so as to face the inner surface 46b of the leaflet 40.

[0067] According to Figure 13, the two lower support members 16a, 16b associated with each leaflet each include a support 19 having a proximal end 19a, an intermediate portion, and a distal end forming a vertex 18. The intermediate portion has a trailing edge that defines a curved guide surface 17. The proximal end 19a is at the proximal side of the lower support members 16a, 16b at the junction between the support 19 and the inner surface 14, and has a curve with a radius of curvature. The vertex 18 extends further in the outflow direction than the leading edge 42 and is located at the distal end of the guide surface 17, as also visible in Figure 8 and 13 . The intermediate portion of the guide surface 17 is located between the proximal end 19a and the vertex 18 and curves away from the vertex 18 in the inflow direction upstream of the antegrade flow.

[0068] In addition, the lower support members 16a, 16b are aligned with the central portion 46 of the leaflet 40. Thus, in the closed position, a lower support region 52 is formed at the position where the central portion 46 of the inner surface 46b of the leaflet 40 contacts the vertex 18 of the guide surface 17. The lower support region 52 includes a vertex support region (i.e., the portion of the vertex 18 that contacts the leaflet) and a leaflet support region (i.e., the portion of the inner surface 46b of the leaflet that contacts the vertex 18). When the leaflet 40 moves from the open position to the closed position in the antegrade outflow direction, the vertex support region and the leaflet support region cooperate to stop the leaflet 40; this in turn defines the closed position of the leaflet 40. However, since the intermediate portion curves away from the leaflet 40, there may be a gap between the intermediate portion of the guide surface 17 and the leaflet 40, as shown in Figure 13 . That is, in the embodiment of Figure 13 , the guide surface 17 extends inwardly into the central passage and upwardly (i.e., in the outflow direction) to the vertex 18.

[0069] In addition, the vertex 18 does not contact the leading edge 42, but contacts a portion of the inner surface 46b that retreats from the leading edge 42. Thus, the vertex 18 is positioned far enough from the leading edge 42 to avoid wear of the leading edge 42 and to provide structural support for the vertex 18, but not so far as to interrupt the flow. It should also be noted that in one embodiment, the vertex 18 of the lower support members 16a, 16b has a width. Thus, the vertex and the leaflet support region are not finite points, but can be linear, or the vertex 18 can be a flat surface (e.g., rectangular or square) to further support the inner surface 46b of the leaflet, distribute the force of the leaflet 40 contacting the vertex 18, and further reduce any hammering effect.

[0070] As the valve transitions from the open configuration to the closed configuration, the leading edge 42 of each leaflet slides at least partially along the guide surface 17 of the two lower support members 16a, 16b. When the valve 10 is in the closed configuration, as shown in Figure 8 andFigure 9 As can be particularly seen in, the leading edge 42 and the inner surface 46b of the central portion 46 of each leaflet 40 contact Figure 6 the two lower support members 16a, 16b particularly shown in.

[0071] The structure of the lower support members 16a, 16b has the advantage of significantly reducing leaflet wear by expanding the contact area, which is different from the heart valve according to WO2008152224, in which, as shown in FIG. 14, the contact area is concentrated at the leading edge of the leaflet, which may lead to premature wear of the leaflet in this area, thus reducing the optimal service life of the heart valve. This structure particularly ensures that the support of the leaflet in the closed configuration occurs on its inner surface 46b. Since the inner surface 46b is substantially flat, it has a large radius of curvature (see Figure 8 and Figure 9 ). Therefore, the inner surface 46b does not need to be completely flat, but has a large enough radius to increase the contact surface. The radius of the inner surface 46a is at least greater than the thickness of the leaflet, and the thickness of the leaflet is greater than the radius at the leading edge. In the closed position, only the vertex 18 of the guide surface 17 contacts the inner surface 46b of the central portion 46. Importantly, the leading edge 42 of the leaflet 40 does not contact the vertex 18 and is not used to stop the movement of the leaflet; thus, this avoids wear of the leading edge 42, avoids any hammering effect on the leading edge 42, and ensures a reliable seal between the leading edge 42 and the inner wall 14 in the closed position. The very low wear risk has the advantage of increasing the diversity of materials that can be used.

[0072] The applicant has found that for the heart valve 10 of the present invention, during the accelerated wear test, the wear on the leaflet 40 at the contact area of the lower support members 16a, 16b can reach 30 microns; while under the same conditions, the wear on the contact area of the support member disclosed in WO2008152224 exceeds 100 microns, which can cause the leaflet 42 to detach from the valve 10.

[0073] Therefore, one aspect of the present disclosure is that when the leaflet moves to the closed position, the leading edge 42 of the leaflet is not used to stop the movement of the leaflet. In one embodiment, during the rotation of the leaflet from the open position to the closed position, the leading edge 42 (which may include a part of the rotational curvature at the leading edge) remains in contact with the guide surface 17, and the inner surface 46b only contacts the vertex 18 in the closed position. In that case, the lower support area 52 is away from the leading edge 42 and also away from any rotational bending of the leading edge 42, such that the support area 52 does not include any part of the leaflet that participates in the rotation of the leaflet, so as to avoid additional wear on the rotating element.

[0074] In accordance with Figure 9 and 13In one embodiment, the distance d1 between the center of the support region 52 against each vertex 18 of the inner surface 46b of the central portion 46 and the leading edge 42 of each leaflet is greater than the thickness t1 of the leaflet at the level of the center of the support region 52 (e.g., the support region 52 cannot be part of the leading edge 42 because the radius of the leading edge 42 is approximately half the thickness). For a valve 10 having an outer diameter of 19 - 29 mm and a leaflet thickness of less than about 1 mm (too thick causes increased flow blockage in the open position), this distance d1 is greater than 0.5 mm and preferably greater than 1 mm. The radius of curvature of the inner surface of the leaflet at the level of the support region 52 is also greater than the thickness t1 of the leaflet at that point. In the context of the present disclosure, the radius of curvature of the inner surface of the leaflet at the support region (where the radius of a flat surface is infinite) is defined as the smallest of the principal radii. This also encompasses small holes or notches in the leaflet that form a spherical joint between the leaflet and the vertex. In other words, the smallest of the two principal radii of curvature of the surface of the support region 52 is greater than the thickness of the leaflet at the support region 52.

[0075] The heart valve 10 further includes support members 34 disposed substantially in the middle and lower portions of each guiding extension 30 ( Figure 5 and Figure 7 ), and which take the form of a bow-shaped element pointing upward (i.e., in the antegrade outflow direction) and are shaped in the outflow direction. Each shaping element 34 of the corresponding guiding extension 30 includes lateral edges that are spaced apart wide enough to act as a support for the lateral edges of the leaflets 40 when the heart valve 10 is in the closed configuration.

[0076] Furthermore, for each leaflet, two so-called upper (i.e., on the outflow side) support members 20a, 20b are arranged at the level of the trailing edge 28 of the annular support 12 ( Figure 6 ), offset axially with respect to the two lower support members 16a, 16b along the longitudinal axis X of the annular support 12. The upper support members 20a, 20b are on the outflow side of the annular support (i.e., in the inflow direction), thus facing the outer surface 46a of the leaflets 40. In addition, the two lower support members 16a, 16b and the two upper support members 20a, 20b of each leaflet can be radially offset with respect to each other, for example, to prevent the two upper support members 20a, 20b from following the placement of the two lower support members 16a, 16b.

[0077] Specifically regarding Figure 16 and 17, each of the two upper support members 20a, 20b can be elongated and have a proximal end, a distal end, and an intermediate portion. This intermediate portion has a leading edge 21' and a trailing edge. The distal end can be a rounded apex 21, which is designed to abut against the outer surface 46a of the central portion 46 of each leaflet 40 throughout the pivoting of the leaflets 40 about their respective axes of rotation as the heart valve 10 transitions from a closed configuration to an open configuration. More specifically, each upper support apex 21 is designed to abut against the upper support region 54 of the outer surface 46a of the central portion 46 of each leaflet during at least 20% or 35% or even 50% of the travel of each leaflet as the heart valve 10 transitions from a closed configuration to an open configuration ( Figure 16 ), which causes the leaflet to rotate about its axis of rotation. This contact can be continuous or intermittent. When the leaflet is pushed open by the flow, the contact is continuous during the first half of the opening.

[0078] The radius of curvature of the upper support region 54 is greater than the thickness of the leaflet at that region, as is the case for the lower support region 52, or in other words, the minimum of the two principal radii of curvature of the surface of the upper support region 54 is greater than the thickness of the leaflet at the upper support region 54. As Figure 17 shown, during most of the opening stroke of the leaflet, each apex 21 contacts the outer surface 46a of the central portion 46 of each leaflet, which is different from the heart valve according to WO2008152224, where, as shown in FIG. 18, the apex of the upper support member contacts the leaflet only at the very beginning of the opening phase and in the leading edge region of the leaflet. Therefore, the shape of the upper support members 20a, 20b is significantly different from the shape of the upper support members disclosed in WO2008152224.

[0079] In particular, the two upper support members 20a, 20b of each leaflet are in the form of protrusions extending inward from the inner wall 14 to overlap the leaflet 40. The two upper support members 20a, 20b are embedded from the downstream trailing edge 28 of the support 12. In one embodiment, the leading edge 21' of the upper support members 20a, 20b is substantially linear to match the outer surface 46a of the leaflet. In addition, the leading edge 21' and in one embodiment the entire support member 20a, 20b are inclined with respect to a plane orthogonal to the longitudinal axis X of the annular support 12 to reliably match the outer surface 46 of the leaflet in the closed position.

[0080] As Figure 16 shown, the leading edge 21' of the upper support member 20b is substantially parallel and flush with the outer surface 46a of the leaflet in the closed position. That is, in the closed configuration, the outer surface 46a of the leaflet forms a predetermined angle in the outflow direction A from the leading edge 42 to the trailing edge 44 (see Figure 1 , 2, 5). In particular, the leading edge 42 is horizontal, and the trailing edge 44 slopes in the outflow direction from the end portion 49 to the trailing edge 45 such that the trailing point 45 extends further in the outflow direction than the leading edge 42 and the end portion 49 by a predetermined angle. Further, the leading edge of the upper support member 20b is at substantially the same predetermined angle as the leaflet in the outflow direction, such that the support leading edge 21' is substantially parallel and flush with the outer surface 46a of the leaflet.

[0081] When the vertex 21 at the distal end of the protrusion coincides with the trailing edge 28 of the annular support 12, the vertex 21 is outside the orthogonal plane. That is, the vertex 21 extends outward in the outflow direction from the downstream trailing edge 28 of the support 12. Each of the two upper support members 20a, 20b includes a lower surface (i.e., the leading edge), which is parallel to the central portion 46 of the leaflet in the closed position.

[0082] Reference Figure 17 , in the open position, the outer surface 46a of the leaflet is close to the vertex 21. At the same time, the curved portion at or adjacent to the leading edge 42 of the leaflet contacts the inner surface of the vertex 18 of the lower support members 16a, 16b (see also Figure 15 ). In the open position, the leaflet contacts the lower support members 16a, 16b at its leading edge 42 and the winglet 48a, where the extension 30 of the annular support is on the surface adjacent to the recess 32. There is a gap from the vertex 21 to avoid adhesion. These features cooperate to prevent the leaflet 40 from further moving from the closed position to the open position. The vertex 21 does not engage the leading edge 42 of the leaflet 40, but is designed to abut against the support area 54 of the outer surface 46a of the leaflet ( Figure 16 - 54 indicates the center of this support area), and this support area 54 retreats a distance d2 from the leading edge 42 of the leaflet, and this distance d2 is greater than the thickness t2 of the leaflet at the center of the support area 54; thus avoiding wear of the leading edge 42 or the rotating element.

[0083] The structure of the upper support members 20a, 20b provides advantages over WO2008152224 in that their contact points with the leaflet are in the low-curvature region of the leaflet, thus limiting the risk of wear. Another advantage is that it provides better guidance to the leaflet when the heart valve 10 changes from the closed configuration to the open configuration, and avoids the leading edge of the leaflet abutting against the inner surface of the annular support, thus causing an undesired reaction force. According to Figure 24 and 25 , the reaction of the upper support member (only the upper support member 20a is visible in Figure 22 ) on the leaflet 40 is exactly opposite to the opening pressure, and thus does not cause any significant reaction of the rotating surface of the recess 32 of the extension 30 on the trailing edge 28 of the leaflet 40. Therefore, the resultant force on the leaflet 40 is almost zero, thus significantly reducing the wear of the leaflet.

[0084] In contrast, referring to FIGS. 23, 26 and 27, for the heart valve disclosed in WO2008152224, the reaction at the leading edge of each leaflet is not parallel to the opening pressure and causes a reaction at the trailing edge, which may lead to premature wear of the leaflet. It can also be appreciated from FIGS. 26 and 27 that the greater the deviation between the opening pressure and the reaction at the leading edge, the greater the reaction at the trailing edge. As a result, this specific function of the upper support member 20a becomes more important the closer the leaflet is to the closed position.

[0085] To avoid the risk of jamming with other components that hold the open position, especially the guide surfaces 32 and the lower support members 16a, 16b, there may be a functional gap between the upper support members 20a, 20b and the outer surface 46a of the leaflet in the open position. This arrangement also allows for a wider selection of leaflet materials, for example by using a material that is a bit more sensitive to wear but has a density closer to that of blood, providing much less inertia during the opening and closing phases. Materials such as PEEK have a density of 1.3, while pyrolytic carbon commonly used in mechanical valve prostheses has a density of 1.7.

[0086] As Figure 1 and 13 depicted, the leading edge 42 of each leaflet 40 is disposed between two lower support members 16a, 16b and two upper support or bearing members 20a, 20b. It will be noted that the components for guiding the rotation of each leaflet define a Figure 22 depicted virtual axis of rotation and are entirely located outside the corresponding leaflet, between the latter and the annular support 12.

[0087] In operation, the heart valve 10 is in the closed position at certain times, which is best shown in Figure 2 、 4 、5、8、13. The leaflets 40 converge together at the trailing edge 44, and the leading edge 42 of the leaflets 40 is flush with the inner wall 14 to provide a reliable seal against blood backflow. Any blood flow in the inflow (upstream antegrade flow) direction will press the leaflets closed, and further movement at the lower support region 52 is prevented by the two lower support members 16a, 16b that support each leaflet 40. Specifically, the apex 18 support region supports the inner surface 46b support region to prevent further movement of the leaflet. The lower support members 16a, 16b are located between the end portions 49a, 49b of the leaflet 40, and the lower support region 52 is set a predetermined distance inward from the leaflet leading edge 42. In addition, the central support member 34 also supports the leaflet flanges 48a, 48b. Referring to Figure 13, the leading edge 42 of the leaflet abuts against the proximal end of the guide surface 17. Since the lower support region 52 (between the apex 18 and the inner surface 46b) is away from the leading edge 42, wear on the leading edge 42 is reduced. There is a small gap between the upper support members 20a, 20b and the outer surface 46a of the leaflet 40, such that the upper support members 20a, 20b are not used in the closed position.

[0088] At a certain point, the leaflet 40 begins to move out of the closed position and towards the open position. The force of the blood flow causes the leaflet 40 to move in the outflow direction. This separates the leaflet 40 from the apex 18. The leaflet 40 moves in the outflow direction A until, as Figure 16 shown, the outer surface 46a contacts the support leading edges of the upper support members 20a, 20b. At this point, turning Figure 17 , the outer surface 46a contacts the apex 21 of the upper support members 20a, 20b. This causes the leaflet 40 to rotate about the apex 21 at the upper support region 54, where the tabs 48a, 48b are guided by the recesses 32 of the guide extensions 30. The upper support region 54 is recessed a predetermined distance from the leading edge 42. The trailing edge 44 of the leaflet 40 rotates to extend in the outflow direction. And the leading edge 42 rotates towards the inner surface of the lower support apex 18. Since the leaflet 40 is separated from the guide surface 17, the leading edge 42 does not contact the guide surface 17 during rotation, which reduces wear on the leading edge 42. The leaflet 40 stops when the tabs 48 contact the edges of the recesses 32 and the leaflet 40 contacts the inner surface of the lower support apex 18.

[0089] When the blood flows in the inflow direction, the blood pushes the leaflet from the open position towards the closed position. The leading edge 42 of the leaflet is guided by the guide surface 17 of the lower support members 16a, 16b. When the inner surface 46b of the leaflet contacts the apex 18, the movement of the leaflet stops.

[0090] Note that in the illustrated embodiment, there are three leaflets 40 and three guide extensions 30. Additionally, each leaflet 40 has two lower support members 16a, 16b and two upper support members 20a, 20b. Having two lower support members and two upper support members 16a, 16b, 20a, 20b distributes wear and pressure more evenly across the leaflet and reduces wear on the leaflet 40. However, any suitable number of elements can be provided, including more or fewer leaflets 40 and guide extensions 30. And each leaflet can have one or more lower support members and / or upper support members.

[0091] The Applicant has found that, according to the valve construction described in WO2008152224, as the leaflets rotate at the start of cardiac systole, the leading edges of the two flanges of each leaflet slide against the inner peripheral surface of the annular support. Now, it has been found that the constant contact between the leading edge and the inner peripheral wall of the annular support according to Figure 20 can create flow recirculation in the occlusion area behind the leaflets, which promotes platelet aggregation and thrombus formation. Figure 20 depicts a partial cross-sectional view of the mechanical heart valve disclosed in WO2008152224 in a plane perpendicular to the longitudinal axis of the annular support.

[0092] According to Figure 11 , 12 and 22, the curvature of the proximal part 43b of the lateral flanges 48a, 48b of each leaflet 40 ( Figure 12 ) has been determined such that the leading edge 42 and the outer surface of each leaflet 40 are at least 0.2 mm, preferably at least 0.3 mm, or 0.4 mm or even 0.5 mm from the inner peripheral wall, over at least 75% of the total width W of each leaflet, and preferably over at least 80%, or 90% when the heart valve 10 is in the open configuration. The curvature of the lateral flanges 48a, 48b of each leaflet 40 has also been determined to promote the opening of a flow channel 50 ( Figure 21 and 22 ) between the inner peripheral wall 14 of the annular support 12 and the outer surface 47a of the flanges 48a, 48b of the leaflet 40.

[0093] In particular, when the leaflet is in the open position according to Figure 1 , each leaflet contacts the inner peripheral wall 14 of the annular support 12 only through the two end portions 49a, 49b of the leaflet, as visible in Figure 22 . Advantageously, the contact area of the leaflet in the open position is less than 15% of the total width W of the leaflet 40 extending between the ends of the two end portions 49a, 49b ( Figure 11 and 12 ), i.e., less than 7.5% at each end portion 49a, 49b. In a preferred embodiment, this contact area of the leaflet is less than 10% of the width W of the leaflet 40, i.e., less than 5% at each end portion 49a, 49b of the leaflet, preferably less than 7.5% of the width W of the leaflet 40, i.e., less than 3.75% at each end portion 49a, 49b of the leaflet, and even more preferably less than 5% of the width W of the leaflet 40, i.e., less than 2.5% at each end portion 49a, 49b of the leaflet, as shown in Figure 22 . In the context of the present invention, the extension 30 of the annular support 12 is an integral part of the inner peripheral wall 14 of the support, and thus, the leaflet contact area at the extension 30 must be included in the above percentages.

[0094] In addition, as shown in Figure 3 , 11 and 12, the distance L between the outer surface 46a of each leaflet 40 in the open position and the inner peripheral wall 14 of the annular support 12 is at least equal to 5% of the diameter of the annular support at the plane of symmetry Z of the leaflet.

[0095] As Figure 22 visible, the axis of rotation of each leaflet 40 is also located in a plane parallel to the central portion 46 of the leaflet. This plane intersects two upper support members 20a, 20b arranged on the inner peripheral wall 14 of the annular support 12. The axis of rotation of each leaflet is also located at a certain distance (in a plane perpendicular to this axis) from the longitudinal axis X of the annular support 12 of the heart valve 10, and this distance is greater than 75% of the radius of the annular support 12.

[0096] As Figure 3 best shown in, the leaflet 40 is configured to form a substantially triangular shape with rounded corners in the open position when arranged in the support 12. The end portion 49 of the leaflet 40 engages with the extension 30, and the planar central portion 46 of the leaflet 40 extends substantially linearly between the extensions 30. Thus, the planar central portion 46 extends inward from the end portion 49 of the small wing 48 to the center of the central portion 46 that is farthest from the inner wall 14 of the support 12. In addition, as Figure 22 best shown in, in the open position, the outer surface 47 of the distal portion 41 extends substantially parallel to the inner wall 14 and contacts the recess 32.

[0097] In addition, the curved proximal portion 43 is configured to start at the end of the recess, such that the small wing 48 immediately turns sharply away from the inner wall 14 of the support 12, thereby forming a gap 50 between the outer surface 47 of the proximal portion 43 and the inner wall 14 of the support 12. This gap 50 forms a channel through which blood can flow. Thus, the distal portion 41 extends axially outward from the extension 30 and then bends inward at the curved proximal portion 43. The central portion 46 extends linearly between the extensions and continues to move away from the inner wall 14, thereby forming a larger gap between the outer surface 46a of the central portion 46 and the inner wall 14. The channel formed by the gap 50 allows blood to flow more easily in the outflow direction. In addition, the straight central portion 46 also minimizes interference with blood flow. Thus, the configuration of the leaflet 40 arranged such that the proximal portion 49 is located at the extension 30 and immediately bends inward linearly to the next adjacent extension 30 provides a widened gap 50 or channel between the leaflet 40 and the inner wall 14. In one embodiment, the distal portion 41 may also bend inward to further widen the gap 50 exactly to the side of the extension 30.

[0098] As Figure 3 As further shown in Figure 3 , the center of the central portion 46 is the maximum distance between the leaflet 40 and the inner wall 14. The lower support or bearing members 16a, 16a are located at the inner wall 14 at the outermost part of the central portion 46, adjacent to the curved proximal portion 43 of the cusp 48, to provide sufficient support when the leaflet 40 enters the closed position. The upper bearing members 20a, 20b may be positioned closer together at the central portion 46.

[0099] When the heart valve 10 transitions from the closed configuration to the open configuration, the curvature of the proximal portion 43 of the lateral cusps 48a, 48b of each leaflet 40 and the shape and positioning of the two lower support members 16a, 16b are such that two flow channels 50 can be formed at the level of the distal portions 49a, 49b of each leaflet 40 between each of the two lower support members 16a, 16b and one of the guiding extensions 30 of the annular support 12. In fact, the gap 50 between the leading edge 42 of the leaflet 40 and the trailing edge 28 of the annular support 12 is defined by the specific curvature of the leaflet, the profile of the trailing edge 28, and the displacement of the axis of rotation that positions the leaflet slightly more downstream relative to the inner peripheral wall 14 in the open position. Especially in Figure 19 , 21 and as illustrated in 21 , the size of each flow channel 50 increases as the leaflets 40 gradually pivot about their respective axes of rotation until the point at which the heart valve 10 is in the open configuration. These flow channels have the advantage of minimizing potential platelet aggregation regions.

[0100] In contrast, when the heart valve transitions from the closed configuration to the open configuration, the heart valve according to WO2008152224 does not have flow channels at the level of the distal portion of each leaflet between each of the two lower support members and one of the guiding extensions of the annular support, as can be seen in Figure 23. This is mainly due to the contact area of the leaflets, which is approximately 20% of the total width of the leaflets, i.e., 10% at each distal portion of the leaflets, as shown in Figure 23. The absence of discharge channels in these critical regions may lead to platelet aggregation, which may induce thrombus formation.

[0101] To manufacture the rigid leaflet valve according to the present invention, there are various materials that can be used. For the annular support, a biocompatible metal such as titanium or cobalt-chromium alloy is, for example, selected. Solid carbon or a carbon coating on graphite can also be used.

[0102] The leaflets themselves are also rigid and can be made of biocompatible materials, such as monolithic carbon, or graphite with a pyrolytic carbon coating. The leaflets can also be made of a biocompatible synthetic polymer that also has wear-resistant properties comparable to pyrolytic carbon. Thus, materials such as "PEEK" (which stands for polyetheretherketone) have a relatively low density of about 1.3 and are particularly suitable for manufacturing leaflets. This material can be carbon-reinforced to increase the wear resistance of the leaflets.

[0103] It will be noted that the valve according to the invention can be made of titanium in the case of the annular support 12 and of PEEK in the case of the leaflets, which provides a material pairing that is perfectly suitable for the friction and wear encountered in this type of valve. In addition, PEEK can also be used as the material for manufacturing the leaflets and the pyrolytic carbon for the support or even the pyrolytic carbon for the leaflets and the support.

[0104] It is further noted that the drawings may illustrate and the description and claims may use several geometric or relational terms as well as terms of direction or orientation, such as shaped, square, rectangular, triangular, linear, curved, curvature, circular, parallel, perpendicular, orthogonal, transverse, axial, round, flat, leading, trailing, forward, up, down, upper, lower, inside, outside, inner, outer, side, distal, and proximal. These terms are merely for convenience in describing the embodiments shown in the drawings and are not used to limit the invention. Thus, it should be recognized that the invention can be otherwise described without those geometric, relational, direction, or orientation terms. In addition, the geometric or relational terms may not be accurate. For example, a wall or surface may not be perfectly flat, perpendicular, or parallel to each other, but is still considered substantially perpendicular or parallel due to, for example, surface roughness, tolerances allowed in manufacturing, etc. And other suitable geometric shapes and relationships can be provided without departing from the scope of the appended claims.

[0105] List of reference numerals

[0106] Mechanical heart valve 10

[0107] Annular support 12

[0108] Inner peripheral wall 14

[0109] Lower support members 16a, 16b

[0110] Support body 19

[0111] Proximal end 19a

[0112] Guide surface 17

[0113] Vertex 18

[0114] Upper support members 20a, 20b

[0115] Vertex 21

[0116] Leading edge 21'

[0117] Outer peripheral wall 22

[0118] Peripheral rib 24

[0119] Leading edge 26

[0120] Trailing edge 28

[0121] Guide extension 30

[0122] Forming recess 32

[0123] Guide arc

[0124] Support member 34

[0125] Movable flap 40

[0126] Leading edge 42

[0127] Trailing edge 44

[0128] Symmetric portions 44a, 44b

[0129] Tip 45

[0130] Central portion 46

[0131] Outer surface 46a

[0132] Inner surface 46b

[0133] Lateral fins 48a, 48b

[0134] Distal portions 41a, 41b

[0135] Proximal portions 43a, 43b

[0136] Outer surface 47a

[0137] Inner surface 47b

[0138] Terminal portions 49a, 49b

[0139] Flow channel 50

[0140] Lower support region 52

[0141] Upper support region 54.

Claims

1. A mechanical prosthetic heart valve (10), comprising: - an annular support (12) comprising an inner peripheral wall (14) centered on a longitudinal axis (X) and defining an internal passageway; - at least two movable leaflets (40) arranged such that each is capable of effecting a rotational movement about a rotational axis perpendicular to the longitudinal axis (X), such that the valve (10) is capable of transitioning from a closed configuration to an open configuration and vice versa, and when the valve is in the open configuration, the leaflets (40) define a main orifice centered on the longitudinal axis therebetween, and blood can flow axially through the main orifice, and when the valve (10) is in the closed configuration, the leaflets (40) at least partially occlude the internal passageway of the annular support (12) so as to be able to prevent blood from flowing back through the main orifice; Each leaflet includes a leading edge (42) designed to abut a portion of the inner peripheral wall (14) of the annular support (12) when the valve is in the closed configuration, an inner surface (46b) extending from the leading edge (42), an outer surface (46a) opposite the inner surface (46b) and extending from the leading edge (42), and two end portions (49a, 49b); The annular support (12) includes two opposite edges (26, 28) and as many extensions (30) as there are leaflets, the extensions (30) extending axially from one of the opposite edges (26, 28), forming recesses (32) on two opposite sides of each extension (30), and when the valve (10) transitions from the open configuration to the closed configuration, the recesses (32) act as guiding surfaces for the respective end portions (49a, 49b) of each leaflet (40) and vice versa, and the annular support (12) further includes two lower support members (16a, 16b) for each leaflet on the inner peripheral wall (14), the two lower support members (16a, 16b) being located between two of the extensions (30) and designed to abut against the corresponding leaflet when the valve (10) is in the closed configuration; characterized in that the contact area of each leaflet (40) in the open position with the inner peripheral wall (14) is less than 15% of the total width (W) of the leaflet (40) extending between the ends of the two end portions (49a, 49b); and wherein, when the heart valve is in the open configuration, the leading edge (42) and the outer surface (46a) of each leaflet (40) are at least 0.2 mm away from the inner peripheral wall (14) over at least 75% of the total width (W) of the leaflet (40).

2. The mechanical prosthetic heart valve (10) according to claim 1, wherein, The mechanical prosthetic heart valve (10) includes three leaflets (40).

3. The mechanical prosthetic heart valve (10) according to claim 1, wherein, The contact area of each leaflet (40) in the open position with the inner peripheral wall (14) is less than 10% of the total width (W) of the leaflet (40).

4. The mechanical prosthetic heart valve (10) according to claim 1, wherein, The contact area of each leaflet (40) in the open position with the inner peripheral wall (14) is less than 7.5% of the total width (W) of the leaflet (40).

5. The mechanical prosthetic heart valve (10) according to claim 1, wherein, The contact area of each leaflet (40) in the open position with the inner peripheral wall (14) is less than 5% of the total width (W) of the leaflet (40).

6. The mechanical prosthetic heart valve (10) according to claim 1, wherein, Each leaflet includes a central portion (46) and two lateral fins (48a, 48b) symmetrically located on both sides of the central portion (46) with respect to the symmetry plane (Z) of the leaflet. Each lateral fin (48a, 48b) includes a lateral fin outer surface (47a), a lateral fin inner surface (47b), and one of the two end portions (49a, 49b). When the heart valve (10) is in the open configuration, two flow channels (50) are respectively located between a lower support member (16a, 16b) and an adjacent extension (30) of the annular support (12).

7. The mechanical prosthetic heart valve (10) according to claim 6, wherein, The two flow channels (50) are defined by the inner peripheral wall (14) of the annular support (12) and the lateral fin outer surfaces (47a) of the corresponding two lateral fins (48a, 48b).

8. The mechanical prosthetic heart valve (10) according to claim 6, wherein, The lateral fins (48a, 48b) are inclined with respect to the central portion (46) of each leaflet (40). The lateral fins (48a, 48b) have respective first and second curved proximal portions (43a, 43b) with curved lateral fin outer surfaces (47a) extending from the central portion (46), and respective first and second distal portions (41a, 41b) that respectively contact one and the other extension (30) of the annular support (12) when the heart valve (10) is in the open configuration. Wherein, the first and second distal portions (41a, 41b) extend parallel to the inner peripheral wall (14) and are respectively aligned with the one and the other extension (30), and wherein, in the open configuration, the curved lateral fin outer surfaces (47a) of each of the first and second curved proximal portions (43a, 43b) curve away from the inner peripheral wall (14) outside the one and the other extension (30).

9. The mechanical prosthetic heart valve (10) according to claim 6, wherein, When the heart valve (10) transitions from the closed configuration to the open configuration, the two flow channels (50) are formed starting from the pivot of each leaflet (40). The dimensions of the two flow channels (50) associated with each leaflet increase as the leaflet gradually pivots until the point when the valve is in the open configuration.

10. The mechanical prosthetic heart valve (10) according to claim 1, wherein, The surface of the inner peripheral wall (14) of the annular support (12) is a continuous surface without windows at the level of the end portions (49a, 49b) of each leaflet (40).

11. The mechanical prosthetic heart valve (10) according to claim 1, wherein, When the heart valve is in the open configuration, the leading edge (42) and the outer surface (46a) of each leaflet (40) are at least 0.5 mm away from the inner peripheral wall (14) over at least 75% of the total width (W) of the leaflet (40).

12. The mechanical prosthetic heart valve (10) according to claim 1, wherein, When the heart valve is in the open configuration, the leading edge (42) and the outer surface (46a) of each leaflet (40) are at least 0.5 mm from the inner peripheral wall over at least 90% of the total width (W) of the leaflet (40).

13. The mechanical prosthetic heart valve (10) according to claim 1, wherein, In a plane perpendicular to the longitudinal axis (X) of the valve, the axis of rotation of each leaflet (40) is located at a distance from the longitudinal axis (X) such that: the distance is greater than 75% of the radius of the annular support (12).

14. The mechanical prosthetic heart valve (10) according to claim 1, wherein, The distance between the axis of rotation of each leaflet and the outer surface (46a) of the central portion (46) of the leaflet is greater than 0.2 mm.

15. The mechanical prosthetic heart valve (10) according to claim 1, wherein, The distance between the outer surface (46a) of each leaflet in the open position and the inner peripheral wall (14) of the annular support (12) is at least equal to 5% of the diameter of the annular support at the symmetry plane (Z) of the leaflet.

16. The mechanical prosthetic heart valve (10) according to claim 1, comprising three leaflets (40) pivotally mounted between three extensions (30), wherein, When the valve is in the open configuration, six flow channels (50) are formed, which are positioned adjacent to each side of each extension (30).

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