Valve stent and prosthetic valve

Abstract

The present invention relates to a valve stent and a prosthetic valve. The prosthetic valve comprises a skirt, a prosthetic valve leaflet, and the valve stent; the prosthetic valve leaflet is arranged on the inner side of the valve stent and connected to the skirt and the valve stent; the skirt comprises an inner skirt and an outer skirt; the valve stent comprises a flange part and a main body part; the flange part is connected to an inflow end of the main body part, and the flange part comprises an inner layer structure and an outer layer structure arranged from inside to outside; an annular curved surface defined by the inner layer structure does not overlap an annular curved surface defined by the outer layer structure, so that the flange part forms a three-dimensional structure in which the inner layer and the outer layer are distributed in a staggered manner; the outer skirt is connected to the inner skirt along the outer layer structure to form at least one pocket; the pocket defines a pocket opening; and the pocket opening is located on the outer side of the valve stent and arranged towards an outflow end of the main body part. Therefore, when the heart contracts, the pocket expands to fill a gap between the flange part and the native tissue, so that the liquid is prevented from flowing back around the prosthetic valve, better preventing perivalvular leakage.

Description

Valve stents and artificial valves Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a valve stent and an artificial valve. Background Art

[0002] The heart contains four chambers: the right atrium (RA), right ventricle (RV), left atrium (LA), and left ventricle (LV). The pumping action of the left and right sides of the heart generally occurs synchronously throughout the cardiac cycle. The valves separating the atria from the ventricles are called the atrioventricular valves, which act as one-way valves, ensuring the normal flow of blood within the heart chambers. The atrioventricular valve between the left atrium and the left ventricle is the mitral valve, and the atrioventricular valve between the right atrium and the right ventricle is the tricuspid valve. The pulmonary valve directs blood flow to the pulmonary artery, and from there to the lungs; blood returns to the left atrium through the pulmonary veins. The aortic valve directs blood flow through the aorta, and from there to the periphery. There is usually no direct connection between the ventricles or between the atria.

[0003] At the beginning of ventricular filling (diastole), the aortic and pulmonary valves close to prevent backflow from the arteries into the ventricles. Shortly thereafter, the atrioventricular valves open to allow unimpeded flow from the atria into the corresponding ventricles. Shortly after the start of ventricular systole (i.e., ventricular emptying), the tricuspid and mitral valves normally close, forming a seal that prevents backflow from the ventricles into the corresponding atria. When problems occur with the atrioventricular valves, they are unable to function properly, resulting in improper closure. The atrioventricular valves are complex structures that typically include an annulus, leaflets, chordae tendineae, and supporting structures. Each atrium is connected to its valve by the atrial vestibule. The mitral valve has two leaflets, and the attachment or engagement of the corresponding surfaces of each leaflet to each other helps provide closure or sealing of the valve, thereby preventing blood from flowing in the wrong direction. The failure of the leaflets to seal during ventricular systole is called malcoaptation and can allow blood to flow in the opposite direction (regurgitation) through the valve. Heart valve regurgitation can have serious consequences for patients, often leading to heart failure, reduced blood flow, lowered blood pressure, and / or reduced oxygen flow to tissues. Mitral regurgitation can also cause blood from the left atrium to flow back into the pulmonary veins, causing congestion. Severe valvular regurgitation, if left untreated, can lead to permanent disability or death.

[0004] Transcatheter valve replacement surgery involves a catheter-based procedure in which a prosthetic valve is compressed outside the body into a delivery system. The valve is then delivered to the native annulus via a vascular pathway or transcardial apex. The prosthetic valve is then released and fixed to the native annulus, replacing the native valve. Compared to surgical procedures, transcatheter valve replacement does not require extracorporeal circulation, is less invasive, and offers a faster recovery time. Postoperative hemodynamic improvements can be significant. Despite rapid advancements in mitral valve replacement technology, valve design still faces recognized challenges, such as paravalvular leakage. For example, in transcatheter mitral valve replacement, the saddle-shaped annulus of the human mitral valve, coupled with individual anatomical variations in cardiac structure, can result in a variably perfect fit between the prosthetic valve and the annulus after implantation. During cardiac contraction, increased blood pressure within the ventricles pushes the prosthetic valve leaflets closed. If there are areas of incomplete fit between the prosthetic valve and the native annulus, some high-velocity blood flow can be pumped outwards into the atria through these areas, resulting in paravalvular leakage. Paravalvular leakage is a serious postoperative complication with no potential for spontaneous healing. Instead, the leak tends to expand over time, ultimately leading to serious consequences such as heart failure or sudden death. To reduce the risk of paravalvular leakage, existing valve stents are typically oversized to fit the native annulus as closely as possible. However, this approach significantly compresses the native tissue, can damage the myocardium during implantation, and can also lead to outflow tract obstruction.

[0005] It should be noted that the information disclosed in the background technology section of this application is intended to deepen the understanding of the general background technology of this application, and should not be regarded as an admission or any form of implication that the information constitutes prior art already known to those skilled in the art.

[0006] Summary of the Invention

[0007] In view of this, an object of the present invention is to provide a valve stent and an artificial valve that can effectively reduce the risks of paravalvular leakage, myocardial damage and outflow tract obstruction without adopting an over-sizing design.

[0008] To achieve the above-mentioned purpose, the present invention provides a valve stent, comprising a flange part and a main body part, wherein the flange part is connected to the inflow end of the main body part, and the flange part comprises an inner layer structure and an outer layer structure arranged from the inside to the outside, and the outer layer structure and the inner layer structure are both arranged around the central axis of the main body part, and the annular curved surface defined by the inner layer structure does not overlap with the annular curved surface defined by the outer layer structure, so that the flange part forms a three-dimensional structure in an inner and outer staggered distribution manner.

[0009] Optionally, the outer layer structure includes at least one annular wave band, the annular wave band includes multiple outer wave rods connected to the inflow end, all the outer wave rods on the annular wave band are arranged in sequence along the circumference of the inflow end, and the inner layer structure includes multiple inner wave rods connected to the inflow end, all the inner wave rods are arranged in sequence along the circumference of the inflow end, each outer wave rod is correspondingly provided with at least one inner wave rod, and each inner wave rod is within the coverage range of the corresponding outer wave rod.

[0010] Optionally, the number of the outer wave rods in the annular wave band is the same as the number of the inner wave rods, so that each outer wave rod is correspondingly provided with one inner wave rod.

[0011] Optionally, at least part of the inner wave rods are connected to the corresponding outer wave rods via connecting rods, and the connecting rods are flexible structures.

[0012] Optionally, the inner wave rod is bent into an arc shape toward the outer wave rod, so that the inner wave rod forms an angle with the direction of the central axis, and the angle is 30°-90°.

[0013] Optionally, the outer layer structure includes multiple layers of the annular wave segments, and adjacent annular wave segments are connected by connecting ribs.

[0014] Optionally, a stent ring is defined at the connection between the main body portion and the flange portion.

[0015] To achieve the above-mentioned purpose, the present invention also provides an artificial valve, comprising a skirt and artificial leaflets, and also comprising a valve stent as described in any one of the items, wherein the artificial leaflets are arranged on the inner side of the valve stent and are connected to the skirt and the valve stent, the skirt comprising an inner skirt and an outer skirt, the inner skirt being arranged on the inner side of the valve stent, the outer skirt being arranged on the outer side of the valve stent, the outer skirt being connected to the inner skirt along the outer layer structure and forming at least one pocket, the pocket being defined by a bag opening, the bag opening being located on the outer side of the valve stent and arranged toward the outflow end of the main body.

[0016] Optionally, the outer skirt is arranged around the outside of the flange part, and the outer skirt defines the bag opening at the starting edge position of the flange part for fitting the native tissue, or, a stent valve ring is defined at the connection between the main body part and the flange part, and the outer skirt is arranged around the outside of the stent valve ring and the outside of the flange part, and the outer skirt is disconnected at the target position of the flange part for fitting the native tissue to define the bag opening.

[0017] Optionally, when the outer skirt is connected to the inner skirt along the outer layer structure, a plurality of pockets are formed, and the sizes of the plurality of pockets are the same or different.

[0018] Optionally, the porosity of the outer skirt is greater than the porosity of the inner skirt.

[0019] Optionally, the outer layer structure includes at least one annular wave band, the annular wave band includes multiple outer wave rods connected to the inflow end, all the outer wave rods on the annular wave band are arranged in sequence along the circumference of the inflow end, the inner layer structure includes multiple inner wave rods connected to the inflow end, all the inner wave rods are arranged in sequence along the circumference of the inflow end, the outer skirt forms the pocket by covering the outer wave rods and the inner wave rods, and the outer skirt and the inner skirt are sewn and connected on the outer wave rods to define the pocket.

[0020] Compared with the prior art, the valve stent and artificial valve provided by the present invention have at least the following beneficial effects:

[0021] The above valve stent includes a flange part and a main body part, the flange part is connected to the inflow end of the main body part, the flange part includes an inner layer structure and an outer layer structure arranged from the inside to the outside, the outer layer structure and the inner layer structure are both arranged around the central axis of the main body part, the annular curved surface defined by the inner layer structure does not overlap with the annular curved surface defined by the outer layer structure, so that the flange part forms a three-dimensional structure in an inner and outer staggered distribution manner. In this way, after the flange part forms a three-dimensional structure, it is convenient to sew the skirt, it is convenient to form a pocket on the flange part, and it can also make the pocket easy to open. On this basis, the outer skirt is connected to the inner skirt along the outer layer structure to form at least one pocket, and the pocket is defined by a bag opening, which is located on the outside of the valve stent and faces the outflow end of the main body part. In this way, when the artificial valve is implanted at the native valve annulus, even if the outer structure of the flange part does not fit well with the native myocardial tissue, the bulging pocket can fill the gap between the outer structure and the native myocardial tissue, so that the fluid (including blood) cannot flow back from around the artificial valve, thus better avoiding paravalvular leakage, eliminating the need to oversize the valve stent, and better reducing the risks of myocardial damage, outflow tract obstruction, etc., thereby improving the safety of the operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] 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.

[0023] FIG1 is a schematic diagram of the overall structure of a valve stent according to an embodiment of the present invention;

[0024] FIG2 a is a diagram showing an application scenario of an artificial valve according to an embodiment of the present invention being implanted at the mitral valve, wherein the pocket is in a non-inflated state;

[0025] FIG2 b is a schematic diagram of a structure in which a small pocket is provided on each outer wave rod according to an embodiment of the present invention, wherein FIG2 b can be understood as a bottom view of FIG1 ;

[0026] FIG2c is a schematic diagram of a structure in which a large pocket is provided on a plurality of adjacent outer wave rods according to an embodiment of the present invention, wherein FIG2c can be understood as a bottom view of FIG1 ;

[0027] FIG2 d is a diagram illustrating an application scenario in which an artificial valve according to an embodiment of the present invention is implanted at the mitral valve, wherein the pocket is in an expanded and bulging state;

[0028] FIG3a is a schematic structural diagram of an inner wave rod bent toward an outer wave rod to form an arc shape according to an embodiment of the present invention;

[0029] FIG3b is a schematic diagram of the angle of the inner wave rod in FIG3a;

[0030] 4 is a schematic diagram of a valve stent structure in which the top end of an inner wave rod is connected to an outer wave rod via a connecting rod according to an embodiment of the present invention;

[0031] FIG5 is a schematic diagram of the valve stent structure when the connecting rod is a flexible structure according to an embodiment of the present invention.

[0032] The reference numerals are explained as follows: 100-valve stent; 110-flange part; 111-inner structure; 1111-inner wave rod; 112-outer structure; 112A-annular wave band; 113-connecting rod; 1121-outer wave rod; 1122-connecting rib; 120-main part; 121-stent valve ring; 120A-inflow end; 120B-outflow end; 200-skirt; 210-outer skirt; 220-inner skirt; 300-artificial valve leaflet; 400-pocket; 410-bag opening. DETAILED DESCRIPTION

[0033] To make the content of the present invention more clear and understandable, the present invention is further described below in conjunction with the accompanying drawings. Of course, the present invention is not limited to the specific embodiments provided below, and general replacements known to those skilled in the art are also included in the scope of protection of the present invention.

[0034] The terms used in this application document are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application are also intended to include the plural forms, unless the context clearly indicates otherwise. It should be understood that similar words such as "a" or "an" do not indicate a quantity limitation, but rather indicate the presence of at least one; "plurality" indicates a quantity of two or more. Similar words such as "include" or "comprises" mean that the elements or objects appearing before "include" or "comprises" cover the elements or objects listed after "include" or "comprises" and their equivalents, and do not exclude other elements or objects. Secondly, the present invention is described in detail using schematic diagrams, but these schematic diagrams are only for the convenience of detailing examples of the present invention and should not be used as limitations of the present invention.

[0035] The term "circumferential" as used in this application document corresponds to the circumferential direction of the artificial valve; the term "radial" corresponds to the diameter of the artificial valve; the term "axial" corresponds to the central axis of the artificial valve, with the axial direction being perpendicular to the radial direction. The terms "inflow end" and "outflow end" are defined by the position of the artificial valve relative to the native valve annulus after implantation. Based on the normal direction of blood flow, the "inflow end" is the end where blood flows into the artificial valve, and the "outflow end" is the end where blood flows out of the artificial valve. The term "outer diameter" as used in this application document refers to the radial dimension of the artificial valve when deployed; the term "inside" refers to the side radially closer to the central axis than the "outside."

[0036] The object of the present invention is to provide a valve stent and an artificial valve to solve the problem that occurs when the existing artificial valve adopts an oversized design to fit the native valve ring.

[0037] The artificial valve provided by the present invention is applicable to both mitral valve and tricuspid valve. The following description is made with reference to the accompanying drawings, and the following description is schematically illustrated by taking mitral valve replacement as an example.

[0038] 1 , 2a to 2d, and 3 to 5 , the present invention provides an artificial valve, comprising a valve support 100 , a skirt 200 , and artificial valve leaflets 300 . The artificial valve leaflets 300 are disposed on the inner side of the valve support 100 and connected to the skirt 200 and the valve support 100 .

[0039] The artificial valve leaflet 300 dynamically switches between an open state and a closed state. In the closed state, the artificial valve leaflet 300 is tightened or converged in a sealed abutment manner, thereby preventing the backflow of blood from the left atrium (LA) into the left ventricle (LV). The present application does not limit the material of the artificial valve leaflet 300. The artificial valve leaflet 300 can be formed from any suitable material or combination of materials. In some embodiments, biological tissue such as chemically stable tissue from the heart valve of an animal (such as a pig) or pericardial tissue of an animal such as a cow (bovine pericardium) or a sheep (sheep pericardium) or a pig (porcine pericardium) or a horse (equine pericardium) can be selected, preferably bovine pericardial tissue. The artificial valve leaflet 300 can also be made of submucosal tissue of the small intestine. In addition, synthetic materials can also be used for the artificial valve leaflet 300. For example, expanded polytetrafluoroethylene or polyester. Optionally, the material of the artificial valve leaflet 300 also includes thermoplastic polycarbonate polyurethane, polyether polyurethane, segmented polyether polyurethane, silicone polyether polyurethane, silicone-polycarbonate polyurethane, and ultra-high molecular weight polyethylene, and can be a combination of one or more of these materials. In addition, biocompatible polymers can also be used to prepare the artificial valve leaflet 300, optionally including polyolefins, polyethylene glycol, polyether sulfone, polysulfone, polyvinyl pyrrolidone, polyvinyl chloride, other fluoropolymers, silicone polyesters, siloxane polymers and / or oligomers, and / or polylactones, and block copolymers thereof. Optionally, the surface of the artificial valve leaflet 300 is anticoagulant treated to give the artificial valve leaflet 300 an anticoagulant function. The surface of the artificial valve leaflet 300 contains an anticoagulant, which includes but is not limited to heparinized polymers.

[0040] The present application does not limit the material of the valve stent 100. Commonly used materials include stainless steel, titanium, nickel-titanium alloy, cobalt-chromium alloy, etc. In addition, the valve stent 100 can be made of one or more metal materials. The valve stent 100 has a contracted state and an expanded state, and can switch between the contracted state and the expanded state. The contracted state is generally the compressed state of the artificial valve when it is delivered in the delivery system, and the expanded state includes the natural expanded state when there is no external force constraint and the expanded state after implantation in the body tissue.

[0041] In more detail, the valve stent 100 includes a flange portion 110 and a main body portion 120. The main body portion 120 is a tubular structure having an inflow end 120A and an outflow end 120B arranged opposite to each other along its own axial direction. The flange portion 110 is connected to the inflow end 120A of the main body portion 120. The outer diameter of the flange portion 110 is larger than the outer diameter of the connection between the flange portion 110 and the main body portion 120. The outer diameter of the connection between the flange portion 110 and the main body portion 120 is the minimum outer diameter of the flange portion 110. The flange portion 110 and the main body portion 120 are molded separately or integrally. Preferably, the flange portion 110 and the main body portion 120 are integrally molded to simplify the manufacturing process and reduce manufacturing costs. The shape of the main body portion 120 after expansion is not limited, such as common shapes such as cylindrical, conical, or a shape with a stent valve ring. The main body 120 provides several functions for the artificial valve, including supporting the internal artificial leaflets 300 and connecting to a delivery system for manipulation and delivery. The main body 120 can be cut or woven. In this embodiment, the main body 120 is cut and formed integrally with the flange 110. The flange 110 is an annular structure arranged around the central axis of the main body 120 and serves to enhance the sealing and anchoring properties of the artificial valve.

[0042] The flange portion 110 includes an inner layer structure 111 and an outer layer structure 112, which are arranged from the inside to the outside. The inner layer structure 111 and the outer layer structure 112 are both arranged around the central axis of the main body portion 120. Moreover, the annular curved surface defined by the inner layer structure 111 does not overlap with the annular curved surface defined by the outer layer structure 112, so that the flange portion 110 forms a three-dimensional structure in an inner and outer staggered distribution. In other words, the envelope curved surface (annular curved surface) formed around the central axis by the inner layer structure 111 does not overlap with the envelope curved surface (annular curved surface) formed around the central axis by the outer layer structure 112, that is, the inner layer structure 111 and the outer layer structure 112 are not within the same envelope curved surface. Thus, the three-dimensional flange portion 110 is easily sewn to the skirt 200 and connected to the skirt 200 to form the pocket 400. This allows the pocket 400 to be easily opened. Once the pocket 400 is opened, the refluxed liquid can flow smoothly into the pocket 400, causing the pocket 400 to expand smoothly under the action of the inflowing liquid. The three-dimensional flange portion 110 also reduces the impact on the inner skirt 220.

[0043] Referring to Figures 2a to 2d, a skirt 200 is sewn on the basis of the above valve stent 100. The skirt 200 includes an outer skirt 210 and an inner skirt 220. The inner skirt 220 is arranged on the inner side of the valve stent 100 and can cover at least a portion of the inner surface of the valve stent 100. The outer skirt 210 is arranged on the outer side of the valve stent 100 and can cover at least a portion of the outer surface of the valve stent 100. Generally, covering the outer skirt 210 at least on the outer side of the flange portion 110 can better prevent paravalvular leakage. In addition, when sewing the skirt 200, the outer skirt 210 is connected to the inner skirt 220 along the outer layer structure 112 to form at least one pocket 400. The pocket 400 is defined by a pocket opening 410. The pocket opening 410 is located on the outer side of the valve stent 100 and is arranged toward the outflow end 120B of the main body 120. It can be understood that the outer skirt 210 forms the pocket 400 by covering the outer structure 112 and the inner structure 111, and the outer skirt 210 and the inner skirt 220 are sewn on the outer structure 112 to define the pocket 400. Moreover, the outer structure 112 and the inner structure 111 are staggered inside and outside, which facilitates sewing the skirt 200 and also facilitates forming the pocket 400.

[0044] For further understanding, refer to Figures 2a and 2d. After the prosthetic valve is implanted at the mitral valve, when the heart contracts, high-velocity fluid (including blood) within the left ventricle (LV) can flow from the bag opening 410 into the pocket 400 in the direction of arrow A1, causing the pocket 400 to expand. This effectively fills the gap between the outer structure 112 of the flange portion 110 and the myocardium with the expanded pocket 400, preventing blood from flowing back from around the prosthetic valve into the left atrium (LA), thereby preventing paravalvular leakage.

[0045] Therefore, when a paravalvular leak occurs with the artificial valve provided by the present invention, the pocket 400 on the flange portion 110 can be inflated with blood to prevent the leak. This also avoids the use of an oversized valve stent, thereby preventing problems such as myocardial damage and outflow tract obstruction, and improving surgical safety. Furthermore, the provision of pocket 400 further stabilizes the artificial valve and prevents its displacement.

[0046] Furthermore, the outer skirt 210 defines a bag opening 410 at the position where the flange portion 110 is used to fit the native tissue (i.e., the atrial myocardium), ensuring that the bag opening 410 is located on the outside of the flange portion 110 rather than on the outside of the main portion 120. This facilitates the refluxed liquid to enter the pocket 400 efficiently and quickly, allowing the pocket 400 to fully expand and bulge.

[0047] As shown in Figure 2a, in one embodiment, the outer skirt 210 is only arranged around the outside of the flange part 110, and the outer skirt 210 is not set at other positions. At this time, the outer skirt 210 defines a pocket 410 at the starting edge position of the flange part 110 for fitting the myocardium, that is, when sewing the outer skirt 210, the outer skirt 210 starts to sew at the starting position where the flange part 110 fits the myocardium and forms the pocket 410.

[0048] Optionally, the connection between the main body 120 and the flange portion 110 is defined with a stent valve ring 121 (see Figure 2a), and the outer skirt 210 is both arranged around the outside of the stent valve ring 121 and around the outside of the flange portion 110. At this time, the outer skirt 210 is disconnected at the target position of the flange portion 110 for fitting the myocardium to define the pocket 410. Specifically, the outer skirt 210 is sewn starting from the stent valve ring 121 (i.e., the stent valve ring 121 is used as the sewing starting position), then extends toward the flange portion 110, and disconnects the outer skirt 210 at a certain position where the flange portion 110 fits the myocardium to form the pocket 410. The position where the outer skirt 210 is disconnected is not limited and can be any position where the flange portion 110 fits the myocardium, preferably a position close to the stent valve ring 121 as shown in the figure.

[0049] It should be noted that the present application does not limit the outer shape of the flange portion 110, as long as the outer diameter of the flange portion 110 is greater than the outer diameter of the connection between the flange portion 110 and the main body portion 120. For example, the outer layer structure 112 can gradually increase in outer diameter from the outflow end 120B of the main body portion 120 toward the inflow end 120A to form an inverted cone-shaped bell mouth. Alternatively, the outer layer structure 112 can gradually increase in outer diameter from the connection with the main body portion 120, from the outflow end 120B of the main body portion 120 toward the inflow end 120A, and then remain unchanged, thereby forming another bell mouth. In one exemplary embodiment, the outer layer structure 112 is similar to a petal structure, but is not limited to this, as long as the outer layer structure 112 has multiple supporting edges (i.e., the outer layer wave rods 1121 described below) distributed in sequence along the circumferential direction. The outer layer structure 112 is not limited to cutting and can also be formed by splicing and fixing. The annular curved surface of the inner layer structure 111 may be a straight cylindrical curved surface or an outward-turned curved surface with an arc.

[0050] Preferably, the flange portion 110 is obtained by cutting and shaping a single hollow tube, and does not need to be obtained by sewing an inner and outer double-layer frame, so the production is simple and the cost is low.

[0051] Referring to Figures 1, 4, and 5, in this embodiment, the outer structure 112 includes a layer of annular segments 112A, which includes multiple outer rods 1121 connected to the inlet end 120A. All outer rods 1121 on the same layer of annular segments 112A are arranged sequentially along the circumference of the inlet end 120A. The outer rods 1121 are typically V-shaped, quasi-V-shaped, curved, or quasi-curved rods, making them easy to fold and unfold. Adjacent outer rods 1121 on the same layer of annular segments 112A may be directly connected or unconnected, without limitation. For example, in this embodiment, adjacent outer rods 1121 on the same layer of annular segments 112A are connected to the inlet end 120A via a common connecting rod 113. However, in practice, adjacent outer rods 1121 may be independently connected to the inlet end 120A via the connecting rod 113. 3a , in another embodiment, the outer structure 112 includes multiple layers of annular segments 112A, such as two or more layers of annular segments 112A, with adjacent annular segments 112A connected by connecting ribs 1122. The provision of multiple layers of annular segments 112A facilitates changing the linear contact between the outer structure 112 and the atrial wall to surface contact, which not only increases support points but also reduces damage to the myocardium.

[0052] Referring to Figures 1, 3a, 4, and 5, in this embodiment, the inner structure 111 includes multiple inner corrugated rods 1111 connected to the inlet end 120A. All inner corrugated rods 1111 are arranged sequentially along the circumference of the inlet end 120A. Similar to the outer corrugated rods 1121, the inner corrugated rods 1111 are generally V-shaped, quasi-V-shaped, curved, or quasi-curved rods, facilitating folding and unfolding. The number of outer corrugated rods 1121 can be the same as or different from the number of inner corrugated rods 1111, for example, the number of inner corrugated rods 1111 can be greater, equal to, or less than the number of outer corrugated rods 1121.

[0053] In any case, each outer wave rod 1121 is provided with at least one inner wave rod 1111, and each inner wave rod 1111 is within the coverage of the corresponding outer wave rod 1121. The inner wave rod 1111 is nested within the corresponding outer wave rod 1121, but the two are not within the same curved surface, and the size of the inner wave rod 1111 does not exceed that of the outer wave rod 1121. Optionally, the number of outer wave rods 1121 and the number of inner wave rods 1111 in the same layer of annular wave segment 112A are the same, so that each outer wave rod 1121 is provided with an inner wave rod 1111, which has a simple structure and good performance. After the inner wave rod 1111 is provided, the impact on the inner skirt 220 can be reduced when the pocket 400 contracts and expands, reducing the risk of the inner skirt 220 being pulled and broken. In addition, the inner wave rod 1111 can also better support the pocket 400, so that the refluxed fluid can easily enter the pocket 400, thereby improving the effect of preventing paravalvular leakage.

[0054] In practice, when the outer skirt 210 is connected to the inner skirt 220 along the outer structure 112, one or more pockets 400 can be formed, and the number of pockets 400 is set according to actual needs. Generally, pockets 400 are defined in areas prone to paravalvular leakage, and pockets 400 can be provided or not provided in other areas less prone to paravalvular leakage. Furthermore, the outer skirt 210 can be covered in locations where pockets 400 are not provided, but the outer skirt 210 and the inner skirt 220 are connected without forming a pocket 400, or the outer skirt 210 can be not provided in locations where pockets 400 are not provided. Therefore, the coverage of the outer skirt 210 can be set as needed. In addition, when forming multiple pockets 400, the sizes of the multiple pockets 400 can be the same or different. For example, a large pocket 400 can be selected in areas prone to paravalvular leakage, and a small pocket 400 can be selected or not provided in other areas. The following description is exemplified by forming multiple pockets 400.

[0055] As shown in Figure 2b, in one embodiment, the outer skirt 210 covers all outer corrugated bars 1121 and inner corrugated bars 1111, forming a plurality of pockets 400 of equal size. These pockets 400 are independently arranged. The outer skirt 210 is sewn together with the inner skirt 220 along all outer corrugated bars 1121, thereby forming a plurality of independent pockets 400. The two opposite sides of each pocket 400 are sewn to the outer corrugated bars 1121.

[0056] However, for special-shaped stents, such as the mitral valve D-shaped stent, paravalvular leakage is prone to occur at the junction of the anterior leaflet and the posterior leaflet of the mitral valve. In this case, a large pocket 400 can be set at the position corresponding to the junction area of ​​the anterior leaflet and the posterior leaflet. At this time, the outer skirt 210 wraps part of the outer layer wave rod 1121 at the position where paravalvular leakage is prone to occur and is sutured with the inner skirt 220 to form independent pockets 400 of different sizes. Specifically, as shown in Figure 2c, in another embodiment, the outer skirt 210 is sutured together with the inner skirt 220 along multiple adjacent outer layer wave rods 1121 to form an independent large pocket 400 for the junction area where paravalvular leakage is prone to occur. A large pocket 400 can simultaneously wrap at least two adjacent outer layer wave rods 1121 and at least two adjacent inner layer wave rods 1111.

[0057] The skirt 200 can be made of a polymer material or a pericardial biomaterial. Preferably, the material of the outer skirt 210 coated on the flange portion 110 should be able to block and / or slow down the flow of blood at the point where the flange portion 110 fits with the myocardium, reduce hemodynamic scour, and increase the thrombus formed in the fitting area to further prevent paravalvular leakage. The porosity of the outer skirt 210 and the porosity of the inner skirt 220 can be the same or different. In this embodiment, the porosity of the outer skirt 210 is greater than the porosity of the inner skirt 220. Optionally, the pore size on the outer skirt 210 is 90 microns to 160 microns, and the pore size on the inner skirt 220 is less than 90 microns. Specifically, the material of the outer skirt 210 is a polymer material with a larger porosity, especially a knitted fabric, and the knitted fabric includes but is not limited to Knitted PET (knitted PET) material. By setting the outer skirt 210 to have a relatively high porosity, blood (particularly red blood cells) can be allowed to enter the contact area between the flange portion 110 and the myocardium, while preventing large thrombi from leaving this contact area. The contact area, which is heavily filled with thrombi, can be used to seal the internal structure of the prosthetic valve (including the inner layer 111, the inner skirt 220, and the prosthetic valve leaflets 300), further stabilizing the prosthetic valve. Furthermore, the inner skirt 220 is made of a polymer material or pericardial tissue material with a relatively low porosity, such as, but not limited to, PET, to effectively prevent blood leakage.

[0058] As shown in Figures 1, 4 and 5, in one embodiment, the inner wave rod 1111 is arranged parallel to the central axis of the stent body 120, so that the inner wave rod 1111 extends along the direction of the central axis in a direction away from the outflow end 120B. At this time, the outer wave rod 1121 is inclined outward relative to the inner wave rod 1111, thereby staggering the inner layer structure 111 and the outer layer structure 112 in the radial direction.

[0059] As shown in Figures 3a and 3b, in another embodiment, the inner corrugated bars 1111 are curved toward the outer corrugated bars 1121 to increase the support of the skirt 200 and reduce the difficulty of sewing the skirt 200. In this case, the inner corrugated bars 1111 form an angle θ with the central axis. This angle θ does not exceed 90°. Preferably, it is between 30° and 90°, and more preferably, between 40° and 60°. This prevents excessive angles from penetrating the annular surface of the outer structure 112, while also preventing excessive angles from reducing support. Furthermore, the curved structure of the inner corrugated bars 1111 reduces the forces acting between the inner skirt 220 and the inner corrugated bars 1111 during contraction and expansion of the pocket 400, reducing the risk of the inner skirt 220 being torn.

[0060] As shown in Figures 1 and 3a, in one embodiment, there is no direct connection between the inner wave struts 1111 and the outer wave struts 1121. As shown in Figure 4, in another embodiment, at least a portion of the inner wave struts 1111 is connected to the outer wave struts 1121 at corresponding locations via connecting rods 113. In practice, connecting rods 113 can be added to the top of the inner wave struts 1111, connecting to the inner wave struts 1111. Connecting rods 113 can better support the pocket 400, allowing refluxed fluid to more easily enter the pocket 400, further improving the effectiveness of preventing paravalvular leakage. Connecting rods 113 can be rigid or flexible. A rigid structure means that the connecting rods 113 are not easily deformed or bent, while a flexible structure means that they are easily deformed and bent. Given that the outer wave struts 1121 need to be in close contact with the myocardium at the native valve annulus and therefore experience significant movement during cardiac activity, the connecting rods 113 are preferably flexible to minimize their impact on the inner wave struts 1111. The connecting rod 113 can be made of a flexible material and / or have a flexible structure. In practice, the connecting rod 113 can be made into a flexible structure by at least one method. The following is an exemplary description.

[0061] As shown in FIG5 , in one example, the connecting rod 113 has a wavy structure, which enables it to be retracted. As a variation, the wavy structure is replaced by a spring. In other embodiments, the connecting rod 113 is made of a flexible material (including an elastic material). It should also be noted that the inner wave rod 1111 is connected to the stent wave rod at the inflow end 120A of the main body 120. The flexible structure of the connecting rod 113 can reduce the movement of the outer wave rod 1121 transmitted to the inner wave rod 1111, which is beneficial to maintaining the stability of the valve orifice size and shape of the artificial valve, which is beneficial to sealing and can increase anchoring.

[0062] As described above, the present invention provides a valve stent and artificial valve that optimizes the flange portion into an inner layer structure and an outer layer structure. This effectively prevents paravalvular leakage while avoiding oversizing, and also mitigates risks such as myocardial damage and outflow tract obstruction. Furthermore, a skirt wraps around the inner and outer layers to form a pocket, preventing paravalvular leakage. The pocket is inflated by refluxed fluid, filling the gap between the flange and the myocardium. This effectively prevents paravalvular leakage and is adaptable to various native valve annulus shapes, providing excellent flexibility. Furthermore, this two-layer flange can be obtained by cutting and shaping a single hollow tube, making it relatively easy to manufacture, simplifying the manufacturing process, and reducing manufacturing costs.

[0063] It should be noted that those skilled in the art may make several improvements and additions without departing from the disclosure of the present invention, and such improvements and additions shall also be considered within the scope of protection of the present invention. Any equivalent changes, modifications, and evolutions made by those skilled in the art using the technical content disclosed above without departing from the spirit and scope of the present invention shall be considered equivalent embodiments of the present invention; at the same time, any equivalent changes, modifications, and evolutions made to the above embodiments based on the essential technology of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A valve stent, characterized in that: It includes a flange part and a main body part, the flange part is connected to the inflow end of the main body part, the flange part includes an inner layer structure and an outer layer structure arranged from the inside to the outside, the outer layer structure and the inner layer structure are both arranged around the central axis of the main body part, the annular surface defined by the inner layer structure does not overlap with the annular surface defined by the outer layer structure, so that the flange part forms a three-dimensional structure in an inner and outer staggered distribution manner.

2. The valve stent according to claim 1, characterized in that: The outer layer structure includes at least one annular wave band, which includes a plurality of outer wave rods connected to the inflow end, and all the outer wave rods on the annular wave band are arranged in sequence along the circumference of the inflow end. The inner layer structure includes a plurality of inner wave rods connected to the inflow end, and all the inner wave rods are arranged in sequence along the circumference of the inflow end. At least one inner wave rod is corresponding to each outer wave rod, and each inner wave rod is within the coverage range of the corresponding outer wave rod.

3. The valve stent according to claim 2, characterized in that: The number of the outer wave rods in the annular wave band is the same as the number of the inner wave rods, so that each outer wave rod is correspondingly provided with one inner wave rod.

4. The valve stent according to claim 2, characterized in that: At least part of the inner wave rods are connected to the corresponding outer wave rods via connecting rods, and the connecting rods are flexible structures.

5. The valve stent according to claim 2, characterized in that: The inner wave rod is bent into an arc shape toward the outer wave rod, so that the inner wave rod forms an angle with the direction of the central axis, and the angle is 30°-90°.

6. The valve stent according to claim 2, characterized in that: The outer layer structure includes multiple layers of the annular wave segments, and adjacent annular wave segments are connected by connecting ribs.

7. The valve stent according to claim 1 or 2, characterized in that: A stent ring is defined at the connection between the main body portion and the flange portion.

8. An artificial valve, comprising a skirt and an artificial valve leaflet, characterized in that: It also includes a valve stent as described in any one of claims 1-7, the artificial valve leaflet is arranged on the inner side of the valve stent and connected to the skirt and the valve stent, the skirt includes an inner skirt and an outer skirt, the inner skirt is arranged on the inner side of the valve stent, the outer skirt is arranged on the outer side of the valve stent, the outer skirt is connected to the inner skirt along the outer layer structure and forms at least one pocket, the pocket is defined by a bag opening, the bag opening is located on the outer side of the valve stent and is arranged toward the outflow end of the main body.

9. The artificial valve according to claim 8, characterized in that: The outer skirt is arranged around the outside of the flange part, and the outer skirt defines the pocket at the starting edge position of the flange part for fitting the native tissue.

10. The artificial valve according to claim 8, characterized in that: A stent valve ring is defined at the connection between the main body and the flange part, and the outer skirt is arranged around the outside of the stent valve ring and the outside of the flange part. The outer skirt is disconnected at the target position of the flange part for fitting the native tissue to define the bag opening.

11. The artificial valve according to any one of claims 8 to 10, characterized in that: When the outer skirt is connected to the inner skirt along the outer layer structure, a plurality of pockets are formed, and the plurality of pockets have the same size.

12. The artificial valve according to any one of claims 8 to 10, characterized in that: When the outer skirt is connected to the inner skirt along the outer layer structure, a plurality of pockets are formed, and the sizes of the plurality of pockets are different.

13. The artificial valve according to any one of claims 8 to 10, characterized in that: The porosity of the outer skirt is greater than the porosity of the inner skirt.

14. The artificial valve according to any one of claims 8 to 10, characterized in that: The outer layer structure includes at least one annular wave band, the annular wave band includes a plurality of outer wave rods connected to the inflow end, all the outer wave rods on the annular wave band are arranged in sequence along the circumference of the inflow end, the inner layer structure includes a plurality of inner wave rods connected to the inflow end, all the inner wave rods are arranged in sequence along the circumference of the inflow end, the outer skirt forms the pocket by covering the outer wave rods and the inner wave rods, and the outer skirt and the inner skirt are sewn and connected on the outer wave rods to define the pocket.

15. The artificial valve according to claim 14, characterized in that: Two opposite sides of each pocket are sewn to the outer wave bar.

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