CN216168093U - Prosthetic heart valve prosthesis - Google Patents

Abstract

The utility model relates to a prosthetic heart valve prosthesis, including support and valve, the valve includes at least two pieces of valve leaflet, the top and bottom of the valve leaflet are fixed to support separately, the bottom of the valve leaflet forms the free edge of valve leaflet that can open and close, the free edge of valve leaflet forms the interval with support when opening completely, and the cross sectional area of the outflow end after the support expands is greater than the cross sectional area of the inflow end, so that each valve leaflet is parallel to axis of the support when the valve is fully opened, when the blood flow flows through the valve, there is no radial component force to valve leaflet, impact to valve leaflet is reduced, have improved the life-span of valve leaflet.

Description

Prosthetic heart valve prosthesis

Technical Field

The utility model relates to the technical field of medical instruments, in particular to a prosthetic heart valve prosthesis.

Background

The heart contains four chambers, the Right Atrium (RA), the Right Ventricle (RV), the Left Atrium (LA), and the Left Ventricle (LV). The pumping action on the left and right sides of the heart generally occurs simultaneously throughout the cardiac cycle. A ventricular inflow channel is formed between the atrium and the ventricle, a left ventricular outflow channel is formed between the left ventricle and the aorta, and a right ventricular outflow channel is formed between the right ventricle and the pulmonary artery. Valves with the function of 'one-way valves' exist at the ventricular inflow channel and the ventricular outflow channel to ensure the normal flow of blood in the heart cavity. When a problem occurs with the valve, the hemodynamics of the heart change and the heart functions abnormally, which is called valvular heart disease.

With the development of socioeconomic and the aging of population, the incidence rate of valvular heart disease is obviously increased, and researches show that the incidence rate of valvular heart disease of the old people over 75 years old is up to 13.3%. At present, the traditional surgical treatment is still the first treatment method for patients with severe valvular diseases, but for the patients with advanced age, complicated multiple organ diseases, chest-open operation history and poor cardiac function, the traditional surgical treatment has high risk and high death rate, and some patients even have no operation chance. The transcatheter valve replacement adopts a catheter intervention method, compresses the artificial valve in vitro to a delivery system, delivers the artificial valve to a diseased valve of a human body, and releases and fixes the artificial valve at a native valve ring to replace the native valve. Compared with the surgical operation, the transcatheter valve replacement operation does not need an extracorporeal circulation auxiliary device, has small wound and quick recovery of the patient, and can obviously improve the hemodynamic index of the patient after the operation.

Although prosthetic valve replacement techniques have been developed at a rapid pace, there are several recognized challenges in valve design, such as prosthetic valve life. Through the artificial valve of pipe implantation, the valve leaf generally adopts biomaterial, and the life-span of biological valve has the limitation, and the valve leaf has the risk of interfering at the switching in-process, and the valve leaf can cause certain degree of damage if receive the friction for a long time, greatly reduced artificial valve's life-span. Traditional support is mostly cylindrical structure, avoids the leaflet to take place to interfere with the support inner wall when the motion, generally adopts two kinds of modes to solve: firstly, adding a clamping piece at the free edge sewing position of the valve leaf to ensure that the sewing point is far away from the inner wall of the bracket; secondly, the free edge of the valve leaf is tightened, so that the valve leaf is kept in a tightened state in an opening state. Although the two modes can prevent the valve leaflets from beating to the inner wall of the bracket when being opened, in the first scheme, the clamping pieces are easy to attach at the suturing positions of the clamping pieces to generate neoplasms, so that the calcification of the valve leaflets is accelerated; in the second scheme, the free edge of the valve leaflet is in a tensioned state, so that when the valve leaflet is opened, the free edge (outflow channel) of the valve leaflet and the inflow channel of the support form an inclined plane, and blood has larger radial component force on the valve leaflet when flowing through the valve, so that the force value of the valve leaflet at the sewing position is increased, and the service life of the valve leaflet is reduced. However, the prior art does not solve the problems well.

SUMMERY OF THE UTILITY MODEL

Accordingly, an object of the present invention is to provide a prosthetic heart valve prosthesis, which can prevent a leaflet from flapping on a stent when the leaflet is opened, does not require a clip, can prevent the leaflet from being calcified by the leaflet being accelerated due to the fact that a neoplasm is easily attached to a suture position of the clip, and can reduce the impact of blood flow on the leaflet when the free edge of the leaflet is in a tense state, thereby improving the lifespan of the leaflet.

In order to achieve the above object, the present invention provides a prosthetic heart valve prosthesis, comprising a stent and a valve, wherein the valve comprises at least two valve leaflets, the top end of each valve leaflet is fixed on the inflow end of the stent, the bottom end of each valve leaflet is fixed on the outflow end of the stent, the bottom end of the valve leaflet is formed with a valve leaflet free edge capable of being opened and closed, and the valve leaflet free edge forms a gap with the stent when the valve leaflet free edge is completely opened; and the cross-sectional area of the outflow end of the stent after expansion is greater than the cross-sectional area of the inflow end so that each leaflet is parallel to the stent axis when the valve is fully open.

Optionally, the cross-sectional area of the expanded stent increases sequentially from the inflow end to the outflow end.

Optionally, the valve forms a circular opening when fully open, the cross-section of the opening being an inscribed circle of the cross-section of the outflow end.

Optionally, the outflow end is composed of a plurality of sections of circular arcs connected end to end in sequence, the number of the circular arcs is the same as that of the valve leaflets, the radius of each circular arc is the same, and the circular arcs are adjacent to each other and are in smooth transition connection.

Optionally, the number of the valve leaflets is three, the outflow end is composed of three arcs connected end to end, and when the valve is fully opened, the valve forms a circular opening, and the cross section of the opening is an inscribed circle of the cross section of the outflow end.

Optionally, an orthographic projection of the inflow end after the stent is expanded is an inscribed circle of an orthographic projection of the outflow end.

Optionally, the gap between the leaflet free edge and the stent when fully open is 1mm to 10 mm.

Optionally, the gap between the leaflet free edge and the stent when fully open is 1mm to 5 mm.

Optionally, the cross-sectional shape of the inflow end and/or the outflow end of the stent after expansion is circular, polygonal, D-shaped, or petal-shaped.

Optionally, the prosthetic heart valve prosthesis further comprises a skirt for sealing the stent.

The cross section area of the inflow end is smaller than that of the outflow end after the support is constructed to be expanded, so that when the valve is completely opened, each valve leaflet can be parallel to the support shaft under the condition that a gap exists between each valve leaflet and the support, the radial component force generated by blood flow flowing through the valve leaflet is eliminated, the impact on the valve leaflet is reduced, the service life of the valve leaflet is prolonged, the support cannot be flapped by the valve leaflet in the opening and closing process, the damage to the valve leaflet is reduced, the service life of the valve leaflet is ensured, and the durability of the valve is good. And above-mentioned prosthetic heart valve prosthesis keeps the cross sectional area of inflow end unchangeable under the condition, the effective open area of valve increases, and the blood flow is more smooth and easy that flows when passing through.

The outflow end of the preferred support of the artificial heart valve prosthesis consists of a plurality of sections of arcs with the same radius, the adjacent arcs are in smooth transition connection, and the cross section of the opening formed when the valve is completely opened is the inscribed circle of the outflow end of the support.

Drawings

Fig. 1a is a schematic perspective view of a prior art prosthetic heart valve prosthesis with the valve in a fully open state.

Fig. 1b is a top view of a prior art prosthetic heart valve prosthesis when fully open.

FIG. 1c is a top view of a prior art prosthetic heart valve prosthesis when fully closed, with orthographic projections of the inflow and outflow ends of the stent coincident.

FIG. 2 is a perspective view of a preferred embodiment of the prosthetic heart valve prosthesis of the present invention, with the skirt not shown.

Fig. 3 is a schematic perspective view of a prosthetic heart valve prosthesis according to a preferred embodiment of the present invention when fully open.

Fig. 4 is a top view of a preferred embodiment prosthetic heart valve prosthesis of the present invention when fully open.

Fig. 5 is a top view of a preferred embodiment of the prosthetic heart valve prosthesis of the present invention fully closed, wherein the orthographic projections of the inflow and outflow ends of the stent do not coincide, preferably the orthographic projection of the inflow end is an inscribed circle of the orthographic projection of the outflow end.

Fig. 6 is a schematic structural view of a stent according to a preferred embodiment of the present invention.

Detailed Description

To further clarify the objects, advantages and features of the present invention, a more particular description of the utility model will be rendered by reference to the appended drawings. It is to be noted that the drawings are in a very simplified form and are not to precise scale, which is merely for the purpose of facilitating and distinctly claiming the embodiments of the present invention.

As used herein, "top end" and "bottom end" are in the direction of blood flow through the prosthetic heart valve prosthesis, although "top end" and "bottom end" are not intended to be limiting, the term "top end" generally refers to the end proximate to the flow of blood into the prosthetic heart valve prosthesis, and the term "bottom end" generally refers to the end proximate to the flow of blood out of the prosthetic heart valve prosthesis. As used herein, "proximal" refers to the end near the apex of the heart during surgery; "distal" means the end distal to the apex of the heart. As used in this specification, the singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise. As used in this specification, the term "or" is generally employed in its sense including "and/or" unless the content clearly dictates otherwise. Furthermore, the terms "radial" or "lateral" refer to a direction perpendicular to the axis of the prosthetic heart valve prosthesis; "axial" refers to a direction parallel to the axis of the prosthetic heart valve prosthesis.

As background art, in order to avoid interference between the leaflets and the inner wall of the stent during movement, in the second scheme, the free edges of the leaflets are tightened to keep the leaflets in a tightened state in an open state, but this way causes a large radial component force on the leaflets when blood flows through the valve, resulting in large impact on the leaflets and reduced leaflet life.

Fig. 1a to 1c show a prosthetic heart valve prosthesis according to the second embodiment, which includes a stent 1 and a valve 2. The valve 2 comprises at least two leaflets 21, the at least two leaflets 21 being capable of opening and closing. The leaflets 21 are attached to the stent 1 at both the top and bottom ends, wherein the leaflet bond points 22 and leaflet free edges 23 are formed when the leaflets 21 are attached to the outflow end 12 of the stent 1 at the outflow end 12 of the stent 1. When blood flows from the inflow end 11 to the outflow end 12, the valve 2 is subjected to blood flow scouring, the leaflet attachment points 22 and the leaflet tips remain fixed, and the leaflet free edges 23 can close and open under the blood flow scouring.

As shown in fig. 1a and 1b, the leaflet free edge 23 is tensioned when the valve 2 is opened, so that the leaflet 21 is kept in a tensioned state in the opened state to form a gap g with the stent 1, thereby preventing the leaflet 21 from beating against the inner wall of the stent 1 when opening and avoiding friction between the leaflet 21 and the stent 1. When not subject to blood flow flushing, the leaflets 21 close, as shown in figure 1 c. However, this method has a large radial component force on the leaflet 21, and the impact on the leaflet 21 is large, which reduces the life of the valve 2.

The inventors have found that the main cause of the above problem is that the leaflet 21 forms an angle θ with the direction of the blood flow scouring force F when the leaflet 21 opens, and that a large radial component force Fr is imparted to the leaflet 21 when blood flows through the valve 2. Wherein the component of the blood flow scouring force F in a direction parallel to the surface of the leaflet 21 is Fa, Fa ═ F cos θ; the component of the blood flow scouring force F in the direction perpendicular to the surface of the leaflet 21 is Fr, where Fr is F sin θ and is not equal to 0.

The inventors have further investigated that the cross-sectional dimensions of the outflow end 12 and the inflow end 11 of the stent 1 are the same, as shown in fig. 1 c. As shown in fig. 1b, when the leaflets 21 are open and the leaflet free edges 23 are tensioned, the cross-section of the entire valve 2 at the bottom end is non-circular and located inside the outflow end 12, and at this time, the cross-sectional area of the valve 2 at the bottom end is smaller than the cross-sectional area of the inflow end 11, so that the leaflets 21 are inclined with respect to the axis of the stent 1 when open, and therefore, the blood flow scouring force F impacts the leaflets 21, and the opening area of the valve 2 is small, and the blood flow is not smooth.

In order to solve the technical problems, the utility model provides a novel artificial heart valve prosthesis, wherein the valve leaflet cannot flap the support wall when being opened, the damage of the valve leaflet can be reduced, the service life of the valve leaflet is prolonged, the valve leaflet is parallel to the axis of the support when being completely opened, and when blood flows through the valve, the blood flow has no radial component force on the valve leaflet, the impact on the valve leaflet is reduced, the service life of the valve leaflet is effectively prolonged, and the durability of the valve prosthesis is improved.

The artificial heart valve prosthesis is used for replacing a diseased valve to achieve the aim of treating valvular heart disease, and can be used for replacing an aortic valve, a pulmonary valve, a tricuspid valve or a mitral valve.

The heart valve prosthesis proposed by the present invention will be further described in detail with reference to the accompanying drawings.

As shown in fig. 2 and 3, the present invention provides a prosthetic heart valve prosthesis (herein, simply referred to as a valve prosthesis) comprising a stent 100, a valve 200 and a skirt (not shown). Both the valve 200 and the skirt are secured to the holder 100, wherein the skirt is also typically fixedly attached to the valve 200 and is closer to the inflow end 101 of the holder 100 than the valve 200. The skirt is used for realizing the function of a sealing support, and ensures that a single channel of blood flow flows from the inflow end 101 of the valve prosthesis to the outflow end 102 of the valve prosthesis, so that perivalvular leakage and regurgitation can be effectively prevented. The skirt can be arranged on a single surface or on two surfaces, namely the skirt is covered on the inner surface or the outer surface of the whole bracket 100 or on two surfaces, so that the sealing function is realized. The skirt is made of animal pericardium or other biocompatible polymer materials, the animal pericardium is pig pericardium or bovine pericardium, and the biocompatible polymer materials are PET (polyethylene terephthalate) and PTFE (polytetrafluoroethylene). The area, area and material of the skirt arrangement are set mainly according to actual clinical requirements, and the present invention does not relate to the improvement of the structure of the skirt, so the skirt is not shown in the drawings and will not be described in detail.

The stent 100 has opposite inflow and outflow ends 101 and 102; the inflow end 101 is the end where blood flows into the valve prosthesis, and the outflow end 102 is the end where blood flows out of the valve prosthesis. Therefore, the outflow end 102 is located downstream of the inflow end 101 according to the direction of blood flow, and defines the direction from the inflow end 101 to the outflow end 102 as the axial direction of the stent 100.

The support 100 is configured to have a mesh structure with a plurality of rows of constituent units, in this embodiment, the constituent units are diamond-shaped structures, which has the advantage of simple forming process, and the formed diamond-shaped mesh surface is more flat. Of course, in other embodiments, the constituent units may also be triangular, square, pentagonal, quasi-circular, drop-shaped, etc. grid units that can form a closed shape, and a square includes a rectangle and a square. Wherein the shape, size and number of the constituent units are selected according to the material, process, size of lesion site, etc. of the stent.

The stent 100 may be selected to be self-expanding or passively expanded. Passive expansion of the stent 110 is achieved, such as by balloon expansion of the stent 100. The stent 100 is fabricated from a shape memory alloy, which may be responsive to temperature changes to transition between a contracted delivery state and an expanded deployed state, allowing the stent 100 to self-expand and self-expand without the aid of an external mechanism. Specifically, stent 100 may be formed from materials such as nitinol, titanium alloy, cobalt chromium alloy, MP35N (nonmagnetic nickel cobalt chromium molybdenum alloy), 316 stainless steel, L605 (cobalt chromium alloy), Phynox/Elgiloy, platinum chromium alloy, or other biocompatible metallic materials as known to those skilled in the art. Preferably, the stent 100 is made of shape memory alloy, more preferably, the stent 100 is made of nickel-titanium alloy tubes by cutting, the outer diameter of the nickel-titanium alloy tubes can be 5-15 mm, the outer diameter of the tubes is the size in a natural state, and the diameter of the shaped stent is selected according to actual needs.

The cross-sectional shape of the stent 100 may be various shapes such as a circle, a quasi-circle, a D-shape, a flower shape, or other irregular or regular shape. Irregular shapes are generally referred to as allotypes; the regular shape is typically a centrosymmetric image or an axisymmetric figure. In actual use, the shape of the stent 100 is determined mainly according to the shape at the lesion site to which it is applied. The quasi-circular shape is a hexagon and a polygon having six or more sides, which is substantially close to a circle, and the flower shape is a petal shape.

Further, the stent 100 may also include a fixation portion that is coupled to the delivery system, such as a delivery sheath, to secure the prosthetic heart valve prosthesis in a fixed position relative to the delivery system during loading into the delivery system, release from the delivery system, and delivery in vivo. Referring to fig. 2, in this embodiment, the securing portion is a tab 104 disposed proximal to the outflow end 102, the tab 104 for attachment to a delivery system. Of course, in other embodiments, the fixing portion may be disposed at the distal end of the inflow end 101, or at both the proximal end of the outflow end 102 and the distal end of the inflow end 101.

The application does not limit the anchoring form of the prosthetic heart valve, a flange can be arranged on the support 100, a self-expanding anchoring form can be adopted, anchoring structures such as thorns and anchor claws can be arranged on the support to grab native tissues, a tether can be anchored to the ventricular wall for fixing, and the anchoring can be realized in a combination of multiple ways. The self-expanding anchoring mode is that the diameter of the valve prosthesis is larger than the size of the native tissue, so that the native tissue can be extruded after the valve prosthesis is released, and the anchoring effect is generated. The specific anchoring form should be chosen according to the actual treatment requirements.

The valve 200 is assembled to the stent 100 and provides two or more leaflets 210. At least two leaflets 210 are disposed in the stent 100, the top end of each leaflet 210 is fixedly connected to the inflow end 101 of the stent 100 by, for example, suturing, the bottom end of each leaflet 210 is fixedly connected to the outflow end 102 of the stent 100 by, for example, suturing, and the edges of the at least two leaflets 210 are butted against each other in the circumferential direction. The material of the valve leaflet 210 is preferably biological tissues such as porcine pericardium and bovine pericardium, and can also be a high polymer material with good biocompatibility. In this embodiment, the leaflets 210 are three, the three leaflets 210 are disposed within the stent 100 along the circumference of the stent 100, and each leaflet 210 is generally the same size and shape.

As shown in fig. 3 to 5, at the inflow end 101 of the stent 100, the tip of each leaflet 210 is sutured to the stent 100 and the leaflets 210 are not in contact with each other (i.e., do not overlap each other). At the outflow end 102 of the stent 100, the bottom end of each leaflet 210 is sutured to the outflow end 102 of the stent 100 and forms a leaflet bond point 201 and a leaflet free edge 202. When the valve 200 is subjected to blood flow scouring, the leaflet combining points 201 and the top ends of the leaflets 210 remain fixed, and the leaflet free edges 202 can be closed and opened under the blood flow scouring.

As shown in fig. 3 and 4, when the valve 200 is fully opened, the leaflet free edge 202 of each leaflet 210 is also tensioned, so that each leaflet 210 is kept in a taut state in the opened state and forms a gap 103 with the stent 100, and each leaflet 210 is prevented from beating against the stent 100 when being opened, thereby preventing friction between the leaflets 210 and the stent 100 and ensuring the service life of the leaflets. In particular, the stent 100 is configured such that the cross-sectional area of the expanded outflow end 102 is larger than the cross-sectional area of the inflow end 101, thereby forming a structure with a small inflow end 101 and a large outflow end 102, such that when the valve 200 is fully opened, each leaflet 210 is parallel to the axis of the stent 100, i.e., each leaflet 210 is parallel to the blood flow scouring force F, thereby eliminating the radial component in the direction perpendicular to the leaflet 210, reducing the impact on the leaflet 210, effectively improving the lifespan of the leaflet, and increasing the durability of the valve prosthesis.

Furthermore, the cross-sectional area of the expanded stent 100 is sequentially increased from the inflow end 101 to the outflow end 102, the process is simple, and the using effect is better.

The cross-section of the inflow end 101 and the outflow end 102 may be various shapes, such as circular, polygonal, D-shaped, or petal-shaped as described above, which is not limited in this application. In general, the cross-sectional shapes of the inflow end 101 and the outflow end 102 are circular for use in an aortic valve, and in other cases, the cross-sectional shapes of the inflow end 101 and the outflow end 102 are D-shaped for use in a mitral valve. In addition, the cross-sectional shapes of the inflow end 101 and the outflow end 102 may be the same or different, such as in the present embodiment, after the stent 100 is expanded, the inflow end 101 is circular, and the outflow end 102 is substantially circular, so that the stent 100 is expanded to be similar to a circular truncated cone shape as a whole, as shown in fig. 6. As shown in fig. 5, in a projection in a direction perpendicular to the axis of the stent 100, the orthographic projection of the inflow end 101 after the stent 100 is expanded is preferably an inscribed circle of the orthographic projection of the outflow end 192.

Preferably, the outflow end 102 of the stent is composed of a plurality of circular arcs connected end to end in sequence, the number of the circular arcs is the same as that of the valve leaflets 210, the radius of each circular arc is the same, and adjacent circular arcs are connected in a smooth transition manner. By "smooth transition joint" is meant a connection with arcs that eliminates sharp corners at the junction of adjacent arcs and ensures that the leaflets 210 form a gap 103 with the arcs when fully open. In this embodiment, the number of the valve leaflets 210 is three, the three valve leaflets 210 are circumferentially arranged, the outflow end 102 is composed of three arcs sequentially connected end to end, the radii of the three arcs are the same, the adjacent arcs are in smooth transition connection, and a gap is formed between the valve leaflet free edge 202 of each valve leaflet 210 and the adjacent arc.

As shown in fig. 4, when the valve 200 is fully opened, there is a gap 103 between the leaflet free edge 202 and the stent, and the width d of the gap 103 can be determined according to the diameter of the valve opening (or the diameter of the inflow end 101) and the diameter of the arc of the outflow end 102. In this embodiment, when the leaflet free edge 202 is fully open, the opening formed by the valve 200 is circular, and the cross section of the valve opening is just the inscribed circle of the cross section of the outflow end 102, at this time, the radius of the valve opening is R (or the radius of the inflow end 101), the radius of the arc of the stent outflow end 102 is R, and the width d of the gap 103 is R-R.

Further, the width d of the gap 103 is 1mm to 10mm, preferably 1mm to 5 mm. Therefore, when the leaflet 210 is fully opened, the leaflet 210 will not flap against the stent wall, which can reduce leaflet damage and increase leaflet life. And when the valve leaflet 210 is fully opened, the opening of the valve 200 is circular, and the valve leaflet 210 vertically faces downwards and is parallel to the flowing direction of blood flow, so that when the blood flow flows through the valve 200, no radial component force is applied to the valve leaflet 210, and the impact on the valve leaflet is reduced.

More specifically, as shown in fig. 3, assuming F is the force of the blood flow flushing the leaflets, with the perpendicular leaflet component Fr, forcing the leaflets to open outward; the component of F in the direction of the leaflets is Fa, causing blood to flow out towards the outflow end 102, and α is the radial angle of the leaflets to the stent. When α is 90 °, Fr ═ F × cos α ═ 0 and Fa ═ F × sin α ═ F, and therefore there is no component force in the radial direction. And under the condition that the cross section size of the inflow end 101 is kept to be the same as that of the prior art, the effective opening area of the valve 200 is increased, the blood flows more smoothly when passing through the valve 200, and the resistance is small.

The above description is only for the purpose of describing the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention, and any variations and modifications made by those skilled in the art based on the above disclosure are within the scope of the present invention.

Claims (10)

1. A prosthetic heart valve prosthesis is characterized by comprising a support and a valve, wherein the valve comprises at least two valve leaflets, the top ends of the valve leaflets are fixed on the inflow end of the support, the bottom ends of the valve leaflets are fixed on the outflow end of the support, the bottom end of the valve is provided with a valve leaflet free edge capable of being opened and closed, and the valve leaflet free edge forms a gap with the support when the valve leaflet is completely opened; and the cross-sectional area of the outflow end of the stent after expansion is greater than the cross-sectional area of the inflow end so that each leaflet is parallel to the stent axis when the valve is fully open.

2. The prosthetic heart valve prosthesis of claim 1, wherein the expanded cross-sectional area of the stent increases in a direction from the inflow end to the outflow end.

3. The prosthetic heart valve prosthesis of claim 1, wherein the valve forms a circular opening when fully open, the opening having a cross-section that is an inscribed circle of a cross-section of the outflow end.

4. The prosthetic heart valve prosthesis of claim 1, wherein the outflow end is comprised of a plurality of segments of circular arcs connected end to end in series, the number of circular arcs being the same as the number of leaflets, the radius of each segment of circular arcs being the same, and adjacent circular arcs being in smooth transition.

5. The prosthetic heart valve prosthesis of claim 4, wherein the number of leaflets is three, the outflow end is comprised of three arcs connected end to end, and when the valve is fully open, the valve forms a circular opening having a cross-section that is an inscribed circle of the cross-section of the outflow end.

6. The prosthetic heart valve prosthesis of claim 1, wherein an orthographic projection of the inflow end after expansion of the stent is an inscribed circle of an orthographic projection of the outflow end.

7. The prosthetic heart valve prosthesis of claim 1, wherein the leaflet free edge has a gap of 1mm to 10mm from the stent when fully open.

8. The prosthetic heart valve prosthesis of claim 7, wherein the leaflet free edge has a gap of 1mm to 5mm from the stent when fully open.

9. The prosthetic heart valve prosthesis of claim 1, wherein the cross-sectional shape of the inflow end and/or the outflow end of the stent after expansion is circular, polygonal, D-shaped, or petal-shaped.

10. The prosthetic heart valve prosthesis of claim 1, further comprising a skirt for sealing the stent.

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