CN118766655A - Heart valve prosthesis and preparation method thereof - Google Patents

Abstract

The present invention provides a heart valve prosthesis and a preparation method thereof. The heart valve prosthesis includes a stent and an integrated valve. The integrated valve includes an artificial valve leaflet and a skirt. The integrated valve is sutured and fixed to the stent by sutures. The preparation method includes: obtaining an integrated valve material, subjecting the integrated valve material to cutting, pre-shaping and folding steps in sequence, and finally sewing the folded integrated valve material on the stent to obtain the heart valve prosthesis. The present invention can minimize damage to the valve, increase the durability of the valve, simplify the suture process, reduce production costs, and improve production efficiency.

Description

Heart valve prosthesis and preparation method thereof

Technical Field

The present invention relates to the field of medical devices, and in particular to a heart valve prosthesis and a preparation method thereof.

Background Art

The heart contains four chambers. The left atrium and left ventricle are located on the left side of the heart, and the right atrium and right ventricle are located on the right side of the heart. The ventricular inflow tract is formed between the atrium and the ventricle, the left ventricular outflow tract is formed by the left ventricle and the aorta, and the right ventricle and the pulmonary artery form the right ventricular outflow tract. There are valves with "one-way valve" functions at the ventricular inflow tract and the left ventricular outflow tract to ensure the normal flow of blood in the heart chamber. When there is a problem with the valve, the heart's hemodynamics changes and the heart function is abnormal, which is called valvular heart disease.

With the development of social economy and the aging of the population, the incidence of valvular heart disease has increased significantly. Studies have shown that the incidence of valvular heart disease in the elderly population over 75 years old is as high as 13.3%. At present, traditional surgical treatment is still the first choice for patients with severe valvular disease, but for patients of advanced age, patients with multiple organ diseases, patients with a history of open-chest surgery, and patients with poor heart function, traditional surgical treatment has high risks and mortality rates, and some patients do not even have the opportunity for surgery. Transcatheter valve replacement/repair has the advantages of no need for open-chest surgery, less trauma, and faster patient recovery, and has received widespread attention. In recent years, artificial valve technology has developed rapidly, but there are still some problems that need to be solved, mainly including insufficient valve durability, complex production and preparation process, high production cost, and low production efficiency.

It should be noted that the information disclosed in the background technology section of the present invention is only intended to deepen the understanding of the general background technology of the present invention, and should not be regarded as admitting or suggesting in any form that the information constitutes prior art already known to those skilled in the art.

Summary of the invention

The object of the present invention is to provide a heart valve prosthesis and a preparation method thereof, so as to solve the problems of insufficient durability, complex production and preparation process and high production cost of artificial heart valves in the prior art.

To achieve the above-mentioned object, the present invention provides a heart valve prosthesis, comprising a stent and an integrated valve, wherein the integrated valve comprises an artificial valve leaflet and a skirt, and the integrated valve is sutured and fixed to the stent by sutures.

In one embodiment, the length of the artificial valve leaflet at the outflow tract portion is greater than the length at the inflow tract portion.

In one embodiment, the length of the skirt at the outflow channel portion is greater than or equal to the length at the inflow channel portion, so that the skirt can better fit the stent or tissue.

In one embodiment, the skirt includes an inner skirt and an outer skirt, the inner skirt is arranged on the inner side of the bracket, and the outer skirt is folded on the outer side of the bracket; the length of the inner skirt in the outflow channel part is greater than or equal to the length in the inflow channel part; and/or the length of the outer skirt in the outflow channel part is greater than or equal to the length in the inflow channel part.

In one embodiment, the length of the artificial valve leaflet when expanded is greater than the inner circumference of the stent.

In one embodiment, the length of the inner skirt when deployed is less than or equal to the inner circumference of the stent, and the length of the outer skirt when deployed is greater than the outer circumference of the stent.

In one embodiment, the skirt includes an inner skirt and an outer skirt, the inner skirt is arranged on the inner side of the stent, the outer skirt is folded on the outer side of the stent, and the integrated valve satisfies at least one of the following conditions:

The height of the outer skirt is greater than the height of the inner skirt;

The ratio of the height of the artificial valve leaflet to the length of the inner skirt when unfolded is 0.15 to 0.3;

The ratio of the ear height of the artificial valve leaflet to the length of the inner skirt when unfolded is 0.01 to 0.05.

In one embodiment, each leaflet of the artificial valve leaflet includes a leaflet free edge portion, a clamping ear, a leaflet fixing portion and a leaflet transition portion, the clamping ear is arranged between the two ends of the leaflet free edge portion and the two ends of the leaflet fixing portion, the leaflet transition portion is arranged between the leaflet fixing portion and the skirt, the number of suture stitches of the leaflet fixing portion is 3 stitches, the number of suture stitches of the clamping ear is 2 stitches, the number of suture stitches of the skirt in the circumferential direction of the stent is 3 stitches, and the number of suture stitches of the suture edge of the artificial valve leaflet and the skirt in the axial direction of the stent is 2 stitches.

To achieve the above object, the present invention further provides a method for preparing a heart valve prosthesis, which is used to prepare any one of the heart valve prostheses, and the preparation method comprises:

An integrated valve material is obtained, and the integrated valve material is sequentially subjected to cutting, pre-shaping and folding processes, and finally the folded integrated valve material is sewn onto a stent to obtain a heart valve prosthesis.

In one embodiment, the pre-forming process includes:

The cut integrated valve material is subjected to a pre-forming process by using a shaping tool, wherein the shaping tool comprises a shaping mold and a gravity block;

During the pre-forming process, the cut integrated valve material is placed on the shaping mold, and the gravity block is used to apply circumferential tension to the integrated valve material placed on the shaping mold, and the integrated valve material is tensioned, and the valve material is pre-formed under predetermined conditions.

In one embodiment, the valve material is pre-shaped in a processing chamber containing a cross-linking agent, or the valve material is pre-shaped in a processing chamber with a certain temperature, humidity and processing time.

In one embodiment, the cross-linking agent is glutaraldehyde or genipin.

In one embodiment, the temperature is 60° C.-120° C., the humidity is 10%-80%, and the treatment time is 1-6 hours.

In one embodiment, the folding process includes: placing the pre-shaped integrated valve material in a mold core, so as to fold the pre-shaped integrated valve material into a three-dimensional shape through the mold core.

In summary, the heart valve prosthesis provided by the present invention comprises: a stent and an integrated valve, wherein the integrated valve comprises an artificial valve leaflet and a skirt, and the integrated valve is sutured and fixed to the stent by sutures. Here, the use of the integrated valve can minimize the damage to the valve, increase the durability of the valve, simplify the suture process, reduce production costs, and improve production efficiency.

Since the method for preparing the heart valve prosthesis provided by the present invention and the heart valve prosthesis provided by the present invention belong to the same inventive concept, the method for preparing the heart valve prosthesis provided by the present invention has all the advantages of the heart valve prosthesis provided by the present invention, and therefore the beneficial effects of the method for preparing the heart valve prosthesis provided by the present invention will not be described one by one here.

BRIEF DESCRIPTION OF THE DRAWINGS

Those skilled in the art will appreciate that the accompanying drawings are provided for a better understanding of the present invention and do not constitute any limitation on the scope of the present invention.

FIG1 is a simplified structural schematic diagram of a heart valve prosthesis according to an embodiment of the present invention;

FIG2a is a simplified schematic diagram of the structure of the integrated valve when it is deployed according to an embodiment of the present invention;

FIG2 b is a schematic diagram of the front view of the heart valve prosthesis according to an embodiment of the present invention;

FIG2c is a schematic diagram of the three-dimensional structure of a heart valve prosthesis according to an embodiment of the present invention;

FIG3 is a partial schematic diagram of the embodiment of the present invention when the sutured edges of the valve leaflets are relatively sutured;

FIG4 is a schematic diagram of suture stitches when the integrated valve is deployed according to an embodiment of the present invention;

FIG5 is a scene diagram showing that the heart valve prosthesis according to an embodiment of the present invention can reduce regurgitation when an integrated valve is used, wherein arrows in the diagram indicate regurgitated blood flow;

FIG6a is a flow chart of preparing a heart valve prosthesis according to an embodiment of the present invention;

FIG6 b is a flow chart of preparing a heart valve prosthesis according to another embodiment of the present invention;

FIG7a is a simplified schematic diagram of the structure of a shaping tool according to an embodiment of the present invention;

FIG7b is a top view of the shaping tooling according to an embodiment of the present invention;

FIG8a is a schematic structural diagram of a shaping mold loaded with pericardial tissue according to an embodiment of the present invention;

FIG8b is a schematic structural diagram of a concave mold according to an embodiment of the present invention;

FIG9 is a schematic diagram of the force of an artificial valve leaflet according to an embodiment of the present invention;

FIG10a is a schematic structural diagram of a mold core according to an embodiment of the present invention at a first viewing angle;

FIG. 10 b is a schematic structural diagram of the mold core according to an embodiment of the present invention at a second viewing angle.

In the attached figure:

10-integrated valve material; 100-heart valve prosthesis; 110-stent; 111-stent rod; 120-integrated valve; 121-artificial valve leaflet; 1211-free edge of valve leaflet; 1212-clip ear; 1213-fixed part of valve leaflet; 1214-transition part of valve leaflet; 1215-sewn edge of valve leaflet; 122-inner skirt; 1221-sewn edge of inner skirt; 1222-first side of inner skirt; 123-outer skirt; 1231-sewn edge of outer skirt; 1232-second side of outer skirt; 130-sewing thread; 200-molding tooling; 210-fixed container; 220-support seat; 230-molding mold Tool; 2310-concave mold; 2311-concave surface; 2320-punch mold; 2321-convex surface; 240-gravity block; 300-core; L1-the length of the artificial valve leaflet when it is unfolded, that is, the length of the outflow tract of the artificial valve leaflet; L2-the length of the inner skirt when it is unfolded, that is, the length of the inflow tract of the inner skirt, the outer skirt or the artificial valve leaflet; L3-the length of the outer skirt when it is unfolded, that is, the length of the outflow tract of the outer skirt; H1-the ear height of the artificial valve leaflet; H2-the height of the artificial valve leaflet; H3-the height of the inner skirt; H4-the height of the outer skirt; A-inflow tract; B-outflow tract; F1-circumferential force on the valve leaflet; F2-radial force on the valve leaflet.

DETAILED DESCRIPTION

The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

As used herein, "circumferential" refers to the direction around the central axis of the stent, and "axial" refers to the direction parallel to the central axis of the stent. The "inflow channel" used herein corresponds to the position where blood flows into the prosthesis when the heart valve prosthesis is operated, and the "outflow channel" corresponds to the position where blood flows out of the prosthesis when the heart valve prosthesis is operated.

The core of the present invention is to provide a heart valve prosthesis and a preparation method thereof, so as to solve the problems of the heart valve prosthesis in the prior art, such as insufficient durability, complex production and preparation process, high production cost, low production efficiency, etc.

The following description is made with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features of the embodiments may complement or be combined with each other.

As shown in FIG1 , an embodiment of the present invention provides a heart valve prosthesis 100, which can be implanted in the heart to replace a native valve, such as a mitral valve, a tricuspid valve, an aortic valve or a pulmonary valve, and can enable blood to flow in one direction, and basically has the function of a natural heart valve. The heart valve prosthesis 100 specifically includes a stent 110, an integrated valve 120 and a suture 130. The integrated valve 120 is sutured and fixed to the stent 110 by the suture 130.

The stent 110 can provide several functions for the heart valve prosthesis 100, including serving as the main structure of the valve, carrying the integrated valve 120 for support, and connecting the structure with the delivery system (hanging ears or fixed ears). The stent 110 is a mesh tube-like structure having a contracted state for delivery and an expanded state for deployment. The stent 110 can be woven or cut. The stent 110 can be made of metal materials such as nickel titanium, titanium alloy, cobalt chromium alloy, MP35n, 316 stainless steel, or a biocompatible metal frame made of other biocompatible metals known to those skilled in the art or a laser-cut solid metal tube, preferably nickel titanium alloy. The stent 110 can also be made of elastically or plastically deformable materials, such as balloon-expandable materials.

As shown in Figures 2a to 2c, according to different functions, the integrated valve 120 can be divided into an artificial valve leaflet 121, an inner skirt 122 and an outer skirt 123 connected in sequence. The outer skirt 123 is an optional structure. It should be noted that the integrated valve 120 means that the artificial valve leaflet 121 and the skirt are integrally or integrally formed. In the present invention, the setting of the integrated valve 120 can minimize the damage to the valve and increase the durability of the valve. At the same time, it can simplify the suturing process, reduce production costs, and improve production efficiency. In addition, as shown in Figure 5, when the integrated valve 120 is closed, due to the reduction in the number of suture needles, it is not easy to produce backflow (the arrow is the direction of backflow blood flow), so the tightness is better and the use effect is good.

In the illustrated embodiment, the artificial valve leaflet 121 is three-leaf type and has an open state and a closed state, and can also dynamically switch between the open state and the closed state. When the artificial valve leaflet 121 is in the closed state, the free edges 1211 (see FIG. 2a ) of the artificial valve leaflet 121 are tightly closed or meet in a sealed abutment manner. When the artificial valve leaflet 121 is in the open state, the free edges 1211 of the artificial valve leaflet 121 are opened in a manner of moving away from each other.

As shown in FIG1 , according to the normal flow direction of blood, the heart valve prosthesis 100 is divided into an inflow channel A and an outflow channel B in the axial direction. In order to prevent paravalvular leakage, a skirt is provided at the inflow channel A of the heart valve prosthesis 100, and the skirt can be single-layer or double-layer. The double-layer skirt means that an inner skirt 122 is provided on the inner side of the inflow channel A of the heart valve prosthesis 100 (corresponding to the inner side of the stent), and an outer skirt 123 is provided on the outer side of the inflow channel A of the heart valve prosthesis 100 (corresponding to the outer side of the stent), and the outer skirt 123 is folded on the outer side of the stent 110. The single-layer skirt means that only the inner side of the inflow channel A is provided with an inner skirt 122. The inner skirt 122 is fixedly connected to the artificial valve leaflet 121. In this embodiment, the inner skirt 122 is provided on the inner side of the inflow channel A, and the outer skirt 123 is sutured at the contact position with the native valve ring tissue to effectively prevent paravalvular leakage. The outer skirt 123 can fully wrap around the entire circumference of the stent 110 at the inflow channel A, which can effectively prevent paravalvular leakage. After the heart valve prosthesis 100 is implanted in the body, the inner skirt 122 is closely attached to the inner surface of the stent 110, and the outer skirt 123 is closely attached to the tissue at the native valve to prevent paravalvular leakage and facilitate endothelialization.

The integrated valve 120 can be selected from biological tissues, such as chemically stable tissues from the heart valves of animals (such as pigs), or pericardial tissues of animals, such as cattle (bovine pericardium) or sheep (sheep pericardium) or pigs (pig pericardium) or horses (horse pericardium), preferably bovine pericardial tissue. In addition, synthetic materials can also be used to prepare the integrated valve 120. Synthetic materials are selected from expanded polytetrafluoroethylene or polyester, for example. Optionally, synthetic materials can also be selected from at least one material in thermoplastic polycarbonate polyurethane, polyether polyurethane, segmented polyether polyurethane, silicone polyether polyurethane, silicone-polycarbonate polyurethane, and ultra-high molecular weight polyethylene. Synthetic materials can also be selected from other biocompatible polymers, optionally including polyolefins, elastomers, polyethylene glycol, polyether sulfone, polysulfone, polyvinyl pyrrolidone, polyvinyl chloride, other fluorinated polymers, silicone polyesters, siloxane polymers and/or oligomers, and/or polylactones, and block copolymers using them, specifically a combination of one or more of these materials.

The suture 130 is selected from conventional medical suture materials, including but not limited to PTFE, ePTFE, PE and other materials.

It should be noted that FIG. 2a is a two-dimensional form of the integrated valve 120 after it is unfolded, that is, the form when it is not folded for use. As shown in FIG. 2a, in some embodiments, the length of the artificial valve leaflet 121 in the outflow tract (corresponding to L1) is greater than the length in the inflow tract (corresponding to L2), so that the artificial valve leaflet 121 can be opened and closed freely, better meeting clinical needs. In some embodiments, the length of the skirt in the outflow tract is greater than or equal to the length in the inflow tract (corresponding to L2), so as to improve the performance of the skirt. In one embodiment, the length of the inner skirt 122 in the outflow tract (equivalent to L1) is greater than or equal to the length in the inflow tract (corresponding to L2), so that the inner skirt 122 is in close contact with the stent 110, so that blood flows smoothly into the valve, reducing the risk of thrombosis. In one embodiment, the length of the outer skirt 123 in the outflow tract (corresponding to L3) is greater than or equal to the length in the inflow tract (corresponding to L2), so that the outer skirt 123 is in close contact with the tissue, better preventing paravalvular leakage. In this embodiment, the length of the inner skirt 122 at the outflow channel portion is greater than that at the inflow channel portion, and the length of the outer skirt 123 at the outflow channel portion is greater than that at the inflow channel portion, which has a better effect.

In the illustrated embodiment, the integrated valve 120 presents a waist shape with a small middle and large ends, that is, L3>L2, L1>L2. At this time, the artificial valve leaflet 121 can open and close freely, which better meets clinical needs, and the inner skirt 122 can be closely attached to the stent 110 in a relatively tight manner, so that blood can flow smoothly into the valve, reducing the risk of thrombosis, while the outer skirt 123 can better adhere to the tissue and better prevent paravalvular leakage.

Referring to Fig. 2a, it can be understood that the inner skirt 122 has a first side 1222 joined to the outer skirt 123, and the first side 122 is the inflow channel portion of the integrated valve 120, and the inflow channel portion of the integrated valve 120 includes the inflow channel portion of the artificial valve leaflet 121, the inflow channel portion of the inner skirt 122, and the inflow channel portion of the outer skirt 123. In addition, the outer skirt 123 has a second side 1232 away from the first side 1222, and the second side 1232 is the outflow channel portion of the outer skirt 123. The outer skirt 123 is folded toward the outside of the stent 110 along the first side 1222 of the inner skirt 122. After folding, along the normal flow direction of blood, the length of the outer skirt 123 at the outflow channel portion (i.e., L3) is greater than the length at the inflow channel portion (i.e., L2).

As shown in FIG. 2b , the second side 1232 of the outer skirt 123 can be arranged according to the mesh shape of the stent 110 so that the second side 1232 of the outer skirt 123 matches the mesh shape. It should be understood that the stent 110 includes a plurality of stent rings (not marked) arranged in sequence along its own axial direction, and each stent ring is formed by connecting a plurality of stent rods 111 end to end in sequence. The waveform of the stent ring is usually a sawtooth or a sine wave. Accordingly, the second side 1232 of the outer skirt 123 can be a sawtooth or a sine wave shape, which is conducive to saving materials.

Furthermore, before suturing, a certain amount of redundancy is configured for the artificial valve leaflet 121 so that the length (L1) of the artificial valve leaflet 121 when unfolded is slightly larger than the inner circumference of the stent 110, so that a certain amount of redundancy exists in the circumferential direction of the stent 110. After the artificial valve leaflet 121 is folded into a three-dimensional shape, the artificial valve leaflet 121 can open and close more smoothly and freely, thereby better meeting clinical needs.

Since the inner skirt 122 needs to fit tightly with the stent 110, there is no need to configure redundancy for the inner skirt 122 before suturing, so that the length (L2) of the inner skirt 122 when unfolded is slightly smaller than the inner circumference of the stent 110, or is equal to the inner circumference of the stent 110. After the inner skirt 122 is folded into a three-dimensional shape, the inner skirt 122 is tightly attached to the inner surface of the stent 110, allowing blood to flow smoothly into the valve.

Furthermore, before suturing, a certain amount of redundancy is configured for the outer skirt 123 so that the length (L3) of the outer skirt 123 when unfolded is slightly larger than the outer circumference of the stent 110, so that after the outer skirt 123 is folded into a three-dimensional shape, the outer skirt 123 can better adhere to the tissue and prevent paravalvular leakage.

The integrated valve 120 may be produced in a variety of ways, such as tailoring, cutting, injection molding, thermoforming, etc., and at least one of them may be selected to perform.

2a, each leaflet of the artificial leaflet 121 includes a leaflet free edge portion 1211, a clip ear 1212 and a leaflet fixing portion 1213, and the leaflet free edge portion 1211 and the leaflet fixing portion 1213 are connected by the clip ear 1212. Schematically illustrated in the orientation of FIG2a, the left side of the leaflet free edge portion 1211 and the left side of the leaflet fixing portion 1213 are connected by the left clip ear 1212, and the right side of the leaflet free edge portion 1211 and the right side of the leaflet fixing portion 1213 are connected by the right clip ear 1212. The artificial leaflet 121 also includes a leaflet transition portion 1214, which serves as a transition zone between the artificial leaflet 121 and the inner skirt 122. Functionally, the leaflet transition portion 1214 can play the role of the inner skirt. The present invention does not specifically limit the shape of the free edge portion 1211 of the leaflet, such as a straight shape or an arc shape, the arc shape being an arc shape that is concave toward the inflow channel or an arc shape that is protruding toward the outflow channel. In addition, the leaflet fixing portion 1213 is usually in an arc shape.

Taking into account that the ear 1212 is subjected to greater force, the ear 1212 requires more suture margins than the leaflet fixing part 1213 to meet the strength requirements. In addition, along the normal flow direction of blood, the artificial leaflet 121 opens and closes more widely in the outflow tract than in the inflow tract, and also requires more redundancy. For this reason, the length of the artificial leaflet 121 in the outflow tract (L1) is greater than the length in the inflow tract (L2), so that the artificial leaflet 121 can open and close freely while meeting the strength requirements.

As shown in FIG2a, when unfolded, the artificial leaflet 121 has two opposite leaflet suture edges 1215. As shown in FIG3, when folded, the two leaflet suture edges 1215 are sutured relative to each other through the suture line 130, so that the artificial leaflet 121 can be folded into a three-dimensional shape. Then, the artificial leaflet 121 can be sewn along the stent rod 111 and arranged on the side of the stent 110 to reduce the overall size after suturing. When sewing the artificial leaflet 121, the leaflet fixing portion 1213 is sutured and fixed to the stent rod 111 in the circumferential direction of the stent 110, and the clip ear 1212 is sutured and fixed to the stent rod 111 in the axial direction of the stent 110.

As shown in FIG. 2a , when unfolded, the inner skirt 122 has two inner skirt sewing edges 1221 and the outer skirt 123 has two outer skirt sewing edges 1231. When folded, the two inner skirt sewing edges 1221 are sewn relative to each other through the sewing line 130, and the inner skirt 122 can be folded and placed on the inner side of the bracket 110, and then the inner skirt 122 is sewn to the bracket rod 111. Similarly, the two outer skirt sewing edges 1231 are sewn relative to each other through the sewing line 130, and the outer skirt 123 can be folded and placed on the outer side of the bracket 110, and then the second side 1232 of the outer skirt 123 away from the inner skirt 122 is sewn to the bracket rod 111.

Preferably, the height H4 of the outer skirt 123 is greater than the height H3 of the inner skirt 122, so that the valve has a high fault tolerance after implantation, further reducing paravalvular leakage. Preferably, the height H2 of the artificial valve leaflet 121 and the length (L2) of the inner skirt 122 when expanded are in a certain relationship, and the ratio of H2/L2 is preferably 0.15-0.3, more preferably 0.2-0.25, so as to ensure that the artificial valve leaflet 121 has a good opening and closing shape. Preferably, the ear height H1 of the artificial valve leaflet 121 and the length (L2) of the inner skirt 122 when expanded are in a certain relationship, and the ratio of H1/L2 is preferably 0.01-0.05, more preferably 1/70-1/50, so as to ensure that the valve has sufficient closing margin and reduce the backflow through the center of the valve.

It should also be understood that when a valve is made of multiple parts connected by suturing, backflow is likely to occur at the joints, so more suture needles are required to reduce the gap, thereby reducing backflow. However, more suture needles are likely to damage the material, thereby reducing the life of the valve. The integrated valve 120 of the present invention can reduce the number of suture needles during suturing, thereby reducing backflow and reducing damage to the valve, thereby increasing the life of the valve.

As shown in FIG4 , when the integrated valve 120 is sutured to the stent 110: (1) the number of suture stitches of the leaflet fixing portion 1213 is at least 3, and generally does not exceed 4. In this embodiment, the number of suture stitches of the leaflet fixing portion 1213 is 3, which are respectively located in the middle a, the middle b on the left side, and the middle c on the right side of the leaflet fixing portion 1213; (2) the number of suture stitches of the clip ear 1212 is at least 2, and generally does not exceed 3. In this embodiment, the number of suture stitches of the clip ear 1212 is 2, which are respectively located on the upper side d and the lower side e of the clip ear 1212; (3) the first side 121 of the inner skirt 122 is sutured to the inner skirt 122; 222 At least 3 stitches and no more than 4 stitches are sutured on the circumference of the stent 110, and the suture stitches are arranged at equal angles along the circumference of the stent 110; (4) The second side 1232 of the outer skirt 123 is sutured at least 3 stitches and no more than 4 stitches on the circumference of the stent 110, and the suture stitches are arranged at equal angles along the circumference of the stent 110; (4) The leaflet suture edge 1215, the inner skirt suture edge 1221 and the outer skirt suture edge 1231, each suture edge here is sutured at least 2 stitches in the axial direction of the stent 110. In this embodiment, the number of suture stitches of each suture edge is 2 stitches, respectively on the upper and lower sides along the blood flow direction. Such a simplified suture method can minimize the damage to the material and increase the durability of the valve, while simplifying the suture process, reducing production costs and improving production efficiency.

The embodiment of the present invention further provides a method for preparing a heart valve prosthesis, which is used to prepare the heart valve prosthesis 100 described in this embodiment. The preparation method comprises:

An integrated valve material 10 is obtained, and the integrated valve material 10 is sequentially subjected to cutting, pre-shaping and folding processes, and finally the folded integrated valve material 10 is sewn onto the stent 110 to obtain a complete heart valve prosthesis 100 .

Further, the pre-forming process includes: using the shaping tool 200 to perform pre-forming treatment on the cut integrated valve material; during the pre-forming treatment, the cut integrated valve material 10 is placed on the shaping mold 230 of the shaping tool 200, and the gravity block 240 of the shaping tool 200 is used to apply circumferential tension to the integrated valve material 10 on the shaping mold 230, and the integrated valve material 10 is tensioned, and the valve material 10 is pre-formed under predetermined conditions, as shown in Figures 7a and 7b. The predetermined conditions are set according to the valve material 10. If the valve material 10 is selected from biological tissue, the predetermined conditions are set by a crosslinking agent. If the valve material 10 is selected from a polymer material, the predetermined conditions are set by heat. Usually, the shaping mold 230 and the gravity block 240 are both placed in a processing chamber, so that the valve material 10 on the shaping mold 230 is pre-formed in the processing chamber with predetermined conditions.

As shown in Fig. 7a-7b and Fig. 8a-8b, in one embodiment, the processing chamber is a fixed container 210, and the fixed container 210 is used to hold a cross-linking agent, and the cross-linking agent constitutes a predetermined condition for pre-setting. The type of the cross-linking agent is not particularly limited, and is generally glutaraldehyde, genistein, etc. The cross-linking agent is conducive to the setting of the integrated valve material 10 prepared from biological tissue, and will not destroy the structure of the integrated valve material 10.

In another embodiment, the processing chamber uses a temperature and humidity box, which is configured to have a certain temperature, humidity and processing time, and the temperature, humidity and processing time constitute the predetermined conditions for heat setting. Further, the temperature is 60°C-120°C, preferably 80°C-100°C, the humidity is 10%-80%, preferably 30%-60%, and the processing time is 1-6 hours, preferably 2-4 hours. The predetermined conditions given here can ensure a better predetermined setting effect.

Furthermore, the folding process includes placing the pre-shaped integrated valve material 10 in the mold core 300, so as to fold the pre-shaped integrated valve material 10 into a three-dimensional shape through the mold core 300, as shown in Figures 10a and 10b. Compared with manual folding, the folding effect of the mold core 300 is better, and the folding is more convenient and quicker.

In an exemplary embodiment, as shown in FIG. 6 a , the process of preparing a heart valve prosthesis 100 includes the following steps S( 1 ) to S( 5 ).

Step S(1): Obtaining pericardial tissue. The pericardial tissue is used as the integrated valve material 10.

After obtaining the pericardial tissue, the pericardial tissue is quickly placed in sterile saline (e.g., sterile saline at about 4°C) for cleaning. The cleaned pericardial tissue is stored in saline containing antibiotics (e.g., saline containing 1% antibiotics), and the pericardial tissue is fat stripped, trimmed and cleaned.

Step S(2): Cutting. The pericardial tissue is cut according to the specified leaflet shape. Here, the cutting can be achieved by laser cutting or blade cutting, with laser cutting being preferred.

Step S(3): Pre-shaping. The cut pericardial tissue needs to be pre-shaped to enhance the mechanical properties of the leaflets in the circumferential direction, reduce leaflet wrinkles, and improve leaflet durability. At this time, the shaping mold 230 containing the pericardial tissue and the gravity block 240 are placed in the fixed container 210 together, and the pre-shaping is completed under the action of the cross-linking agent.

Step S (4): Folding: The pre-shaped pericardial tissue is folded to form a three-dimensional pericardial tissue.

Step S(5): Suturing: The folded pericardial tissue is sutured and fixed to the stent 110 to obtain a complete heart valve prosthesis 100.

As shown in FIG6b , in another exemplary embodiment, another heart valve prosthesis 100 is prepared by using the following steps S(1′) to S(5′), in which the pericardial tissue of the above embodiment is replaced by a polymer material.

Specifically, step S(1'): obtaining polymer materials. The polymer materials can be selected from PU, PTFE, PET, SIBS, etc., and the polymer materials for artificial valves can be obtained by synthesis, weaving, heat setting, etc. The polymer materials here are also used as integrated valve materials 10.

Step S(2'): Cutting. The polymer material is cut according to the specified leaflet shape. Similarly, the cutting can be achieved by laser cutting or blade cutting, with laser cutting being preferred.

Step S(3'): Pre-forming. The cut polymer material is pre-formed by the shaping tool 200, and the mechanical properties of the leaflet in the circumferential direction are enhanced by the pre-forming, the leaflet wrinkles are reduced, and the durability of the valve is improved. Specifically, the shaping mold 230 containing the polymer material and the gravity block 240 are placed together in a temperature and humidity chamber, and the thermal pre-forming is completed in the temperature and humidity chamber with a certain temperature, humidity and processing time.

Step S (4'): Folding: The pre-shaped polymer material is also folded by the mold core 300, and the excess polymer material is trimmed off.

Step S (5’): Suturing: The folded polymer material and the stent 110 are sutured and fixed to obtain a complete heart valve prosthesis 100.

As shown in Fig. 7a and Fig. 7b, the embodiment of the present invention further provides a shaping tool 200 for pre-shaping the cut integrated valve material 10. In the following description, pericardial tissue is used as an example for illustration.

In one embodiment, the shaping tool 200 includes a fixed container 210, a support seat 220, a shaping mold 230 and a gravity block 240. The crosslinking agent is contained in the container 210. The support seat 220 is arranged in the container 210 and is used to install the shaping mold 230. The shaping mold 230 is used to place the cut pericardial tissue. The weight of the gravity block 240 is set as required, and it is used to tension the pericardial tissue. The gravity block 240 can be selected as a weight, and the gram weight of the weight is 1g-20g, preferably 5g-15g.

When pre-shaping is required, the cut pericardial tissue is first loaded into the shaping mold 230, and a gravity block 240 of appropriate weight is respectively installed at both ends of the pericardial tissue along the length direction L, so that the gravity blocks 240 at both ends tension the pericardial tissue; then, the shaping mold 230 containing the pericardial tissue is placed on the support seat 220, and immersed in a container 210 containing glutaraldehyde solution, the mass percentage concentration of the glutaraldehyde solution is 0.1% to 1%, preferably 0.3 to 0.7%, and is placed for several days, such as a placement time of not less than 7 days; after the shaping is completed, the shaping mold 230 is taken out, and then the pericardial tissue is removed from the shaping mold 230.

The shaping mold 230 is made of metal material, such as 316 stainless steel, 304 stainless steel and other metal materials, and can also be made of polymer materials, such as PTFE, PET, PE and other polymer materials.

As shown in Fig. 8a and Fig. 8b, the shaping mold 230 includes a separable concave mold 2310 and a convex mold 2320, wherein the concave mold 2310 has a plurality of concave surfaces 2311 arranged in a straight line, and the convex mold 2320 has a plurality of convex surfaces 2321 arranged in a straight line, and the convex surfaces 1321 and the concave surfaces 2311 are matched one by one. The cut pericardial tissue is placed between the convex surface 2321 and the concave surface 2311. The shapes of the convex surface 2321 and the concave surface 2311 are determined according to the required shape of the integrated valve 120. When cutting, a certain margin is retained in the pericardial tissue, and the margin here is convenient for connecting the gravity block 240 at both ends of the pericardial tissue, so that the gravity block 240 can be fixed on the pericardial tissue and exert a certain pulling force on the pericardial tissue. It should be understood that although the pulling force applied by the gravity block 240 is along the direction of gravity, the pulling force applied by the gravity block 240 will eventually be mapped to the circumferential force of the artificial valve in the three-dimensional form.

Refer to Figure 9 for understanding, and take the three-petal integrated valve 120 as an example for explanation. During normal use, the circumferential force F1 of the integrated valve 120 is greater than the radial force F2. Then, during shaping, the gravity block 240 applies tension to the pericardial tissue in the circumferential direction, which enhances the mechanical properties of the integrated valve 120 in the circumferential direction, reduces leaflet wrinkles, and improves leaflet durability. Also refer to Figure 7a, during pre-shaping, the length direction L of the integrated valve material 10 is along the horizontal direction, that is, multiple concave surfaces 2311 are arranged in the horizontal direction, and the concave surfaces 2311 are set upward or downward. In this embodiment, the concave surfaces 2311 are facing upward.

Furthermore, as shown in FIG. 10a and FIG. 10b , an embodiment of the present invention further provides a mold core 300 for folding the shaped integrated valve material 10. The pericardial tissue is used as an example for illustration. The mold core 300 can be made of metal, such as 316 stainless steel, 304 stainless steel, etc., or a polymer material, such as PTFE, PET, PE, etc. The structure of the mold core 300 is determined according to the three-dimensional shape of the integrated valve 120. The pre-shaped pericardial tissue is folded along the mold core 300, and the excess pericardial material is trimmed. Finally, the folded pericardial tissue is sutured and assembled with the stent 110 to form a complete heart valve prosthesis 100.

In summary, the heart valve prosthesis provided by the present invention has at least the following beneficial effects:

(1) The use of an integrated valve can minimize damage to the valve and increase the durability of the valve. At the same time, it can simplify the suturing process, reduce production costs, and improve production efficiency.

(2) The length of the artificial valve leaflet at the outflow tract is greater than that at the inflow tract, allowing the artificial valve leaflet to open and close freely, better meeting clinical needs.

(3) The length of the inner skirt when deployed is less than or equal to the inner circumference of the stent, so that the inner skirt is in close contact with the stent in a relatively tight manner, allowing blood to flow smoothly into the valve and reducing the risk of thrombosis;

(4) The length of the outer skirt at the outflow tract is greater than that at the inflow tract, so that the outer skirt can better adhere to the tissue and better prevent paravalvular leakage.

(5) When preparing the integrated valve, the processing technology was optimized, from raw material acquisition to valve suturing, which greatly simplified the valve production process. In particular, the pre-forming process was added, which effectively enhanced the circumferential mechanical properties of the leaflet and improved the durability of the leaflet.

Therefore, the present invention improves the durability of the valve by optimizing the valve structure and preparation process, and also simplifies the production and preparation process, reduces production costs, and improves production efficiency.

It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referred to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description.

It should also be noted that, although the present invention has been disclosed as a preferred embodiment, the above embodiment is not intended to limit the present invention. For any technician familiar with the art, without departing from the scope of the technical solution of the present invention, the technical content disclosed above can be used to make many possible changes and modifications to the technical solution of the present invention, or modified into equivalent embodiments of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of protection of the technical solution of the present invention.

It should also be understood that, unless otherwise specified or indicated, the terms "first", "second", etc. in the specification are merely used to distinguish between the various components, elements, steps, etc. in the specification, and are not used to indicate the logical relationship or sequential relationship between the various components, elements, steps, etc.

It should also be recognized that the terms described herein are only used to describe specific embodiments and are not intended to limit the scope of the invention. It should be noted that the singular forms "a" and "an" used herein and in the appended claims include plural references unless the context clearly indicates otherwise. For example, a reference to "a step" or "a device" means a reference to one or more steps or devices, and may include secondary steps and secondary devices. All conjunctions used should be understood in the broadest sense. And, the word "or" should be understood to have the definition of a logical "or", rather than a logical "exclusive or", unless the context clearly indicates otherwise. In addition, the implementation of the method and/or device in the embodiments of the present invention may include performing the selected task manually, automatically, or in combination.

Claims (14)

1. A heart valve prosthesis, characterized in that it comprises a stent and an integrated valve, wherein the integrated valve comprises an artificial valve leaflet and a skirt, and the integrated valve is sutured and fixed to the stent by sutures. 2 . The heart valve prosthesis according to claim 1 , wherein the length of the artificial valve leaflet at the outflow tract portion is greater than the length at the inflow tract portion. 3 . The heart valve prosthesis according to claim 1 , wherein the length of the skirt at the outflow channel portion is greater than or equal to the length at the inflow channel portion. 4. The heart valve prosthesis according to claim 3 is characterized in that the skirt includes an inner skirt and an outer skirt, the inner skirt is arranged on the inner side of the bracket, the outer skirt is folded on the outer side of the bracket, the length of the inner skirt in the outflow part is greater than or equal to the length in the inflow part, and/or the length of the outer skirt in the outflow part is greater than or equal to the length in the inflow part. 5 . The heart valve prosthesis according to claim 2 , wherein the length of the artificial valve leaflet when expanded is greater than the inner circumference of the stent. 6 . The heart valve prosthesis according to claim 4 , wherein the length of the inner skirt when expanded is less than or equal to the inner circumference of the stent, and the length of the outer skirt when expanded is greater than the outer circumference of the stent. 7. The heart valve prosthesis according to claim 1 or 2, characterized in that the skirt comprises an inner skirt and an outer skirt, the inner skirt is arranged on the inner side of the stent, the outer skirt is folded on the outer side of the stent, and the integrated valve satisfies at least one of the following conditions: The height of the outer skirt is greater than the height of the inner skirt; The ratio of the height of the artificial valve leaflet to the length of the inner skirt when unfolded is 0.15 to 0.3; The ratio of the ear height of the artificial valve leaflet to the length of the inner skirt when unfolded is 0.01 to 0.05. 8. The heart valve prosthesis according to claim 1 or 2 is characterized in that each leaflet of the artificial leaflet includes a leaflet free edge portion, a clamping ear, a leaflet fixing portion and a leaflet transition portion, the clamping ears are arranged between the two ends of the leaflet free edge portion and the two ends of the leaflet fixing portion, the leaflet transition portion is arranged between the leaflet fixing portion and the skirt, the number of suture stitches of the leaflet fixing portion is 3, the number of suture stitches of the clamping ear is 2, the number of suture stitches of the skirt in the circumferential direction of the stent is 3 to 4, and the number of suture stitches of the suture edge of the artificial leaflet and the skirt in the axial direction of the stent is 2. 9. A method for preparing a heart valve prosthesis, for preparing the heart valve prosthesis according to any one of claims 1 to 8, characterized in that the preparation method comprises: An integrated valve material is obtained, and the integrated valve material is sequentially subjected to cutting, pre-shaping and folding processes, and finally the folded integrated valve material is sewn onto a stent to obtain a heart valve prosthesis. 10. The method for preparing a heart valve prosthesis according to claim 9, wherein the pre-forming step comprises: The cut integrated valve material is subjected to a pre-forming process by using a shaping tool, wherein the shaping tool comprises a shaping mold and a gravity block; During the pre-forming process, the cut integrated valve material is placed on the shaping mold, and the gravity block is used to apply circumferential tension to the integrated valve material placed on the shaping mold, and the integrated valve material is tensioned, and the valve material is pre-formed under predetermined conditions. 11. The method for preparing a heart valve prosthesis according to claim 10, characterized in that the valve material is pre-shaped in a processing chamber containing a cross-linking agent, or the valve material is pre-shaped in a processing chamber with a certain temperature, humidity and processing time. 12 . The method for preparing a heart valve prosthesis according to claim 11 , wherein the cross-linking agent is glutaraldehyde or genipin. 13 . The method for preparing a heart valve prosthesis according to claim 11 , wherein the temperature is 60° C.-120° C., the humidity is 10%-80%, and the processing time is 1-6 hours. 14. The method for preparing a heart valve prosthesis according to any one of claims 9 to 13, characterized in that the folding process comprises: placing the pre-shaped integrated valve material in a mold core, so as to fold the pre-shaped integrated valve material into a three-dimensional shape through the mold core.