Valve stent and artificial valve

Abstract

The present invention relates to a valve stent and an artificial valve. The artificial valve includes a skirt, artificial valve leaflets, and a valve stent. The artificial valve leaflets are disposed inside the valve stent and are connected to the skirt and the valve stent. The skirt includes an inner skirt and an outer skirt. The valve stent includes a flange portion and a main body portion. The flange portion is connected to the inflow end of the main body portion. The flange portion includes an inner layer structure and an outer layer structure arranged from the inside to the outside. 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 portion forms a three-dimensional structure in a manner of internal and external staggered layers. The outer skirt is connected to the inner skirt along the outer layer structure and forms at least one pocket. The pocket is defined with a pocket opening, and the pocket opening is located outside the valve stent and is arranged toward the outflow end of the main body portion. Thus, when the heart contracts, the gap between the flange portion and the native tissue can be filled by the expansion of the pocket, so that the liquid cannot flow back from around the artificial valve, and paravalvular leakage can be better prevented.

Description

Technical Field

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

[0002] The heart contains four chambers, the right atrium (RA), the right ventricle (RV), the left atrium (LA), and the left ventricle (LV). During the entire cardiac cycle, the pumping actions on the left and right sides of the heart generally occur synchronously. The valves that separate the atria from the ventricles are called atrioventricular valves, and the atrioventricular valves act as one-way valves to ensure 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 into the pulmonary artery and from there to the lungs; the blood returns to the left atrium through the pulmonary veins. The aortic valve guides 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 start of ventricular filling (diastole), the aortic valve and the pulmonary valve close to prevent backflow from the arteries into the ventricles. Shortly thereafter, the atrioventricular valves open to allow unobstructed flow from the atria into the corresponding ventricles. Shortly after the start of ventricular systole (i.e., ventricular emptying), the tricuspid valve and the mitral valve normally close, thereby forming a seal that prevents backflow from the ventricles into the corresponding atria. When there is a problem with the atrioventricular valve and it cannot function properly, improper closure results. The atrioventricular valves are complex structures and generally include an annulus, leaflets, chordae tendineae, and supporting structures. Each atrium is connected to its valve through an atrial vestibule. The mitral valve has two leaflets, and the attachment or engagement of the corresponding surfaces of each leaflet with each other helps to provide closure or sealing of the valve, thereby preventing blood from flowing in the wrong direction. Failure of the leaflets to seal during ventricular systole is called poor coaptation and can allow blood to flow backward (regurgitate) through the valve. Valvular insufficiency can have serious consequences for the patient, often leading to heart failure, reduced blood flow, reduced blood pressure, and / or reduced oxygen flow to the body tissues. Mitral insufficiency can also cause blood to flow back from the left atrium into the pulmonary veins, resulting in congestion. Severe valvular insufficiency, if untreated, can lead to permanent disability or death.

[0004] Transcatheter valve replacement surgery is a method of catheter intervention. An artificial valve is compressed outside the body into a delivery system, and along the vascular path or through the apex, it is delivered to the native annulus, and the artificial valve is released and fixed at the native annulus to replace the native valve. Compared with surgical operations, transcatheter valve replacement surgery does not require an extracorporeal circulation assist device, has less trauma, and the patient recovers quickly. After the operation, the hemodynamic indexes of the patient can be significantly improved. Although the technology of mitral valve replacement has developed rapidly, there are still some recognized problems in the design of the valve. For example, the problem of paravalvular leakage of the valve. Taking transcatheter mitral valve replacement surgery as an example, due to the saddle-shaped structure of the human mitral annulus and the differences in the cardiac structural anatomy of different individuals, after the valve is implanted, the fit between the artificial valve and the annulus is not necessarily perfect. When the heart contracts, the blood pressure in the ventricle increases, pushing the leaflets of the artificial heart valve to close. At this time, if there is an area where the artificial valve and the native annulus do not fit perfectly, part of the high-speed blood flow will be pumped out into the atrium through the outer area of this valve, that is, paravalvular leakage occurs. Paravalvular leakage is a serious postoperative complication and has no possibility or tendency of spontaneous healing. Instead, over time, the leakage orifice has a tendency to expand, which may ultimately lead to serious consequences such as heart failure or sudden death. In order to reduce the risk of paravalvular leakage, existing valve stents generally adopt the method of oversize design to fit the native annulus as much as possible. However, this method exerts a relatively large extrusion on the native tissue, and it is easy to damage the myocardium during the implantation process and also easy to cause the problem of outflow tract obstruction.

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

[0006] In view of this, the purpose of the present invention is to provide a valve stent and an artificial valve, which can preferably reduce the risks of paravalvular leakage, myocardial injury, and outflow tract obstruction without adopting an oversize design.

[0007] To achieve the above purpose, the present invention provides a valve stent, which 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. Both the outer layer structure and the inner layer structure are 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 a way of internal and external staggered layers.

[0008] Optionally, the outer structure includes at least one layer of annular wavebands, the annular waveband includes a plurality of outer wave rods connected to the inflow end, all the outer wave rods on the annular waveband are sequentially arranged along the circumferential direction of the inflow end, the inner structure includes a plurality of inner wave rods connected to the inflow end, all the inner wave rods are sequentially arranged along the circumferential direction of the inflow end, at least one inner wave rod is correspondingly arranged for each outer wave rod, and each inner wave rod is within the coverage range of the corresponding outer wave rod.

[0009] Optionally, the number of the outer wave rods in the annular waveband is the same as the number of the inner wave rods, so that one inner wave rod is correspondingly arranged for each outer wave rod.

[0010] Optionally, at least part of the inner wave rods are connected to the corresponding outer wave rods through connecting rods, and the connecting rods are flexible structures.

[0011] Optionally, the inner wave rods are bent into an arc shape towards the outer wave rods, so that an included angle is formed between the direction of the inner wave rods and the central axis, and the included angle is 30°-90°.

[0012] Optionally, the outer structure includes multiple layers of the annular wavebands, and adjacent annular wavebands are connected through connecting ribs.

[0013] Optionally, a stent annulus is defined at the connection between the main body part and the flange part.

[0014] To achieve the above object, the present invention also provides an artificial valve, which includes a skirt and artificial valve leaflets, and also includes the valve stent according to any one of the above, the artificial valve leaflets are arranged inside the valve stent and are connected to the skirt and the valve stent, the skirt includes an inner skirt and an outer skirt, the inner skirt is arranged inside the valve stent, the outer skirt is arranged outside the valve stent, the outer skirt is connected to the inner skirt along the outer structure and forms at least one pocket, the pocket defines a pocket opening, and the pocket opening is located outside the valve stent and is arranged towards the outflow end of the main body part.

[0015] Optionally, the outer skirt surrounds the outside of the flange part, the outer skirt defines the pocket opening at the starting edge position of the flange part for fitting the native tissue, or, a stent annulus is defined at the connection between the main body part and the flange part, the outer skirt surrounds the outside of the stent annulus 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 pocket opening.

[0016] Optionally, when the outer skirt is connected to the inner skirt along the outer layer structure, a plurality of the pockets are formed, and the sizes of the plurality of pockets are the same or different.

[0017] Optionally, the porosity of the outer skirt is greater than the porosity of the inner skirt.

[0018] Optionally, 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 sequentially arranged along the circumferential direction 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 sequentially arranged along the circumferential direction 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 stitched and connected on the outer wave rods to define the pocket.

[0019] Compared with the prior art, the valve stent and the artificial valve provided by the present invention have at least the following beneficial effects:

[0020] 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, both the outer layer structure and the inner layer structure are arranged around the central axis of the main body part, and 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 a staggered distribution manner inside and outside. In this way, after the flange part forms a three-dimensional structure, it is not only convenient for sewing the skirt, but also convenient for forming pockets on the flange part, and the pockets can be easily opened. On this basis, when the outer skirt is connected to the inner skirt along the outer layer structure and at least one pocket is formed, and the pocket is defined with a bag mouth, the bag mouth is located outside 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 annulus, even if the outer layer structure of the flange part does not fit well with the native myocardial tissue, the gap between the outer layer structure and the native myocardial tissue can be filled by the inflated pockets, so that the liquid (including blood) cannot flow back from the periphery of the artificial valve, preferably avoiding paravalvular leakage, without the need for over-sizing the valve stent, preferably reducing the risks of myocardial injury, outflow tract obstruction, etc., and improving the surgical safety. Description of the Drawings

[0021] Those of ordinary skill in the art will understand that the provided drawings are used to better understand the present invention and do not constitute any limitation to the scope of the present invention. Among them:

[0022] Figure 1 is a schematic diagram of the overall structure of the valve stent according to an embodiment of the present invention;

[0023] Figure 2a FIG. Figure 2a is an application scenario diagram of an artificial valve implanted at the mitral valve according to an embodiment of the present invention, where the pocket is in an un-inflated state;

[0024] Figure 2b FIG. Figure 2b is a schematic structural diagram of a small pocket provided on each outer wave rod according to an embodiment of the present invention, where Figure 2b it can be understood as Figure 1 the bottom view of;

[0025] Figure 2c FIG. Figure 2c is a schematic structural diagram of a large pocket provided on multiple adjacent outer wave rods according to an embodiment of the present invention, where Figure 2c it can be understood as Figure 1 the bottom view of;

[0026] Figure 2d FIG. is an application scenario diagram of an artificial valve implanted at the mitral valve according to an embodiment of the present invention, where the pocket is in an inflated state;

[0027] Figure 3a FIG. is a schematic structural diagram of the inner wave rod bending towards the outer wave rod to form an arc according to an embodiment of the present invention;

[0028] Figure 3b is Figure 3a the angle schematic diagram of the inner wave rod in;

[0029] Figure 4 FIG. is a schematic structural diagram of a valve stent where the top end of the inner wave rod is connected to the outer wave rod through a connecting rod according to an embodiment of the present invention;

[0030] Figure 5 FIG. is a schematic structural diagram of a valve stent when the connecting rod is a flexible structure according to an embodiment of the present invention.

[0031] The reference numerals are explained as follows:

[0032] 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 body part; 121 - stent annulus; 120A - inflow end; 120B - outflow end; 200 - skirt; 210 - outer skirt; 220 - inner skirt; 300 - artificial valve leaf; 400 - pocket; 410 - pocket opening. Detailed Embodiments

[0033] To make the content of the present invention clearer and easier to understand, the present invention will be further described below with reference to the accompanying drawings of the specification. Of course, the present invention is not limited to the specific embodiments provided below, and general substitutions well-known to those skilled in the art are also covered by the protection scope 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 "a", "the", and "said" 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 "one" or "a" do not indicate a quantity limitation but rather indicate the existence of at least one; "multiple" indicates a quantity of two or more. "Including" or "comprising" and similar words mean that the elements or items appearing before "including" or "comprising" cover the elements or items listed after "including" or "comprising" and their equivalents, and do not exclude other elements or items. Secondly, the present invention has been described in detail using schematic diagrams, but these schematic diagrams are only for facilitating the detailed description of the embodiments of the present invention and should not be construed as a limitation of the present invention.

[0035] As used in this application document, "circumferential" corresponds to the circumferential direction of the artificial valve; "radial" corresponds to the diameter direction of the artificial valve; "axial" corresponds to the central axis direction of the artificial valve, and the axial direction is perpendicular to the radial direction; the terms "inflow end" and "outflow end" are defined based on the position relative to the native annulus after the artificial valve is implanted in the body. According to the normal blood flow direction, the "inflow end" is the end where the blood flows into the artificial valve, and the "outflow end" is the end where the blood flows out of the artificial valve. The "outer diameter" as used in this application document refers to the radial dimension of the artificial valve when it is deployed; the term "inner side" refers to the side that is closer to the central axis in the radial direction compared to the "outer side".

[0036] The objective of the present invention is to provide a valve stent and an artificial valve to solve the problems that occur when existing artificial valves use oversize designs to fit the native annulus.

[0037] The artificial valve provided by the present invention is applicable to the mitral valve and the tricuspid valve. This will be described below with reference to the accompanying drawings, and in the following description, the mitral valve replacement is used as an example for illustration.

[0038] Refer to Figure 1 、 Figures 2a to 2d 、FIG. 3 to Figure 5 , the present invention provides an artificial valve, which includes a valve stent 100, a skirt 200, and artificial valve leaflets 300. The artificial valve leaflets 300 are disposed on the inner side of the valve stent 100 and are connected to the skirt 200 and the valve stent 100.

[0039] The artificial valve leaflet 300 dynamically switches between an open state and a closed state. When in the closed state, the artificial valve leaflet 300 closes or converges in a sealed abutting manner, thereby preventing the backflow of blood from the left atrium (LA) into the left ventricle (LV). The material of the artificial valve leaflet 300 is not limited in this application. The artificial valve leaflet 300 can be formed of any suitable material or combination of materials. In some embodiments, chemically stable tissues of biological tissues such as heart valves from animals (such as pigs) can be selected, or animal pericardial tissues such as bovine (bovine pericardium), ovine (ovine pericardium), porcine (porcine pericardium), or equine (equine pericardium), preferably bovine pericardial tissue. The artificial valve leaflet 300 can also be made of small intestinal submucosa tissue. 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 further 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. Additionally, biocompatible polymers can also be used to prepare the artificial valve leaflet 300, optionally including polyolefins, polyethylene glycol, polyethersulfone, polysulfone, polyvinylpyrrolidone, polyvinyl chloride, other fluorine-containing polymers, silicone polyester, silicone polymers and / or oligomers, and / or polyesters, and block copolymers using them. Optionally, the surface of the artificial valve leaflet 300 is anticoagulated so that the artificial valve leaflet 300 has an anticoagulant function. The surface of the artificial valve leaflet 300 contains anticoagulants, and the anticoagulants include but are not limited to heparinized polymers.

[0040] This application also does not limit the material of the valve stent 100. Commonly used materials include stainless steel, titanium, nitinol, cobalt-chromium alloy, etc. In addition, the valve stent 100 can be prepared from one or more metal materials. The valve stent 100 has a contracted state and a deployed state and can switch between the contracted state and the deployed state. The contracted state is usually the compressed state when the artificial valve is delivered in the delivery system, and the deployed state includes the natural deployed state without external force constraint and the deployed state after being implanted into 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 greater 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 formed separately or integrally. Preferably, the flange portion 110 and the main body portion 120 are integrally formed to simplify the manufacturing process and reduce the manufacturing cost. The shape of the main body portion 120 after being unfolded is not limited, such as common shapes such as cylindrical, conical, or a shape with a stent valve ring. The main body 120 can provide several functions for the artificial valve, including: carrying the internal artificial valve leaflets 300; being used to connect with the delivery system so as to be manipulated to achieve delivery, release and other functions. The main body 120 can be cut or woven into shape. In this embodiment, the main body 120 is cut and formed, and is cut and formed integrally with the flange part 110. The flange part 110 is an annular structure, which is arranged around the central axis of the main body 120 and is used to improve the sealing and anchoring performance of the artificial valve.

[0042] The flange portion 110 includes an inner layer structure 111 and an outer layer structure 112 arranged from the inside to the outside. The inner layer structure 111 and the outer layer structure 112 are arranged around the central axis of the main body portion 120. Moreover, the annular surface defined by the inner layer structure 111 does not overlap with the annular 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 manner. In other words, the envelope surface (annular surface) formed by the inner layer structure 111 around the central axis does not overlap with the envelope surface (annular surface) formed by the outer layer structure 112 around the central axis, that is, the inner layer structure 111 and the outer layer structure 112 are not within the same envelope surface. In this way, the flange part 110 of the three-dimensional structure is easy to sew the skirt 200, and is also easy to connect with the skirt 200 to form the pocket 400, and the pocket 400 is easy to be opened. After the pocket 400 is opened, the refluxed liquid can smoothly flow into the pocket 400, and then the bag opening 400 can be smoothly expanded and bulged under the action of the inflowing liquid. The flange part 110 of the three-dimensional structure can also reduce the impact on the inner skirt 220.

[0043] refer to Figures 2a to 2d, on the basis of the above valve stent 100, a skirt 200 is sewn. The skirt 200 includes an outer skirt 210 and an inner skirt 220. The inner skirt 220 is disposed inside the valve stent 100 and can cover at least part of the inner surface of the valve stent 100. The outer skirt 210 is disposed outside the valve stent 100 and can cover at least part of the outer surface of the valve stent 100. Generally, at least the outer skirt 210 covers the outside of the flange portion 110, which 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 with a pocket opening 410. The pocket opening 410 is located outside the valve stent 100 and is arranged toward the outflow end 120B of the main body portion 120. It can be understood that the outer skirt 210 forms the pocket 400 by covering the outer layer structure 112 and the inner layer structure 111, and the outer skirt 210 and the inner skirt 220 are sewn on the outer layer structure 112 to define the pocket 400. Moreover, the outer layer structure 112 and the inner layer structure 111 are distributed with an offset inside and outside, which is convenient for sewing the skirt 200 and also for forming the pocket 400.

[0044] For reference Figure 2a and Figure 2d for understanding. After the artificial valve is implanted at the mitral valve, when the heart contracts, the high-speed fluid (including blood) in the left ventricle (LV) can enter the pocket 400 from the pocket opening 410 along the direction of the arrow A1 shown in the figure, causing the pocket 400 to expand and bulge. In this way, the gap between the outer layer structure 112 of the flange portion 110 and the myocardium is well filled by the bulging pocket 400, preventing blood from flowing back from around the artificial valve to the left atrium (LA), thus avoiding paravalvular leakage.

[0045] Therefore, after using the artificial valve provided by the present invention, when paravalvular leakage occurs, the pocket 400 on the flange portion 110 can be congested and bulged to prevent paravalvular leakage, and the method of designing the valve stent with an oversized size can be avoided, thereby avoiding problems such as myocardial injury and outflow tract obstruction, and improving the surgical safety. Moreover, the setting of the pocket 400 can further stabilize the artificial valve and prevent its displacement.

[0046] Further, the outer skirt 210 defines the pocket opening 410 at the position where the flange portion 110 is used to fit the native tissue (i.e., atrial myocardium), ensuring that the pocket opening 410 is located outside the flange portion 110 rather than outside the main body portion 120. This is conducive to the reflux fluid entering the pocket 400 efficiently and quickly, causing the pocket 400 to fully expand and bulge.

[0047] Such as Figure 2aAs shown, 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 arranged 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 be sewn 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 portion 120 and the flange portion 110 defines a stent valve ring 121 (see Figure 2a ), the outer skirt 210 is not only arranged around the outside of the stent valve ring 121, but also around the outside of the flange part 110. At this time, the outer skirt 210 is disconnected at the target position of the flange part 110 for fitting the myocardium to define the pocket 410. Specifically, the outer skirt 210 is sewn from the stent valve ring 121 (that is, the stent valve ring 121 is used as the sewing starting position), and then extends to the flange part 110, and the outer skirt 210 is disconnected at a certain position where the flange part 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 part 110 fits the myocardium, preferably the position close to the stent valve ring 121 shown in the figure.

[0049] It should be noted that the present application does not limit the 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 the outer diameter from the outflow end 120B of the main body portion 120 to the inflow end 120A to form an inverted cone-shaped bell mouth, or the outer layer structure 112 starts from the connection with the main body portion 120, and gradually increases the outer diameter from the outflow end 120B of the main body portion 120 to the inflow end 120A, and then the outer diameter remains unchanged, thereby forming another bell mouth. In an exemplary embodiment, the outer layer structure 112 is similar to a petal structure, but it is not limited to this, as long as the outer layer structure 112 has a plurality of supporting edges (i.e., the outer layer wave rod 1121 described below) distributed in sequence along the circumferential direction. The outer layer structure 112 is not limited to cutting and forming, for example, it 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] refer to Figure 1 , Figure 4 and Figure 5, in this embodiment, the outer structure 112 includes a layer of annular wave bands 112A. The annular wave bands 112A include multiple outer wave rods 1121 connected to the inflow end 120A. All the outer wave rods 1121 on the same layer of annular wave bands 112A are arranged in sequence along the circumferential direction of the inflow end 120A. The outer wave rods 1121 are generally V-shaped rods, V-shaped-like rods, arc-shaped rods or arc-shaped-like rods, which are convenient for folding and unfolding. Whether the adjacent outer wave rods 1121 on the same layer of annular wave bands 112A are directly connected or not is not limited. For example, in this embodiment, the adjacent outer wave rods 1121 on the same layer of annular wave bands 112A are connected to the inflow end 120A through a shared connecting rod 113. In fact, however, the adjacent outer wave rods 1121 can be independently connected to the inflow end 120A through the connecting rod 113. Refer to Figure 3a , in another embodiment, the outer structure 112 includes multiple layers of annular wave bands 112A, such as two layers of annular wave bands 112A or more layers of annular wave bands 112A. The adjacent annular wave bands 112A are connected by connecting ribs 1122. The setting of the multiple layers of annular wave bands 112A is beneficial to changing the line contact between the outer structure 112 and the atrial wall into surface contact, which not only increases the fulcrums but also can reduce the damage to the myocardium.

[0052] Refer to Figure 1 , Figure 3a , Figure 4 and Figure 5 , in this embodiment, the inner structure 111 includes multiple inner wave rods 1111 connected to the inflow end 120A. All the inner wave rods 111 are arranged in sequence along the circumferential direction of the inflow end 120A. Similar to the outer wave rods 1121, the inner wave rods 1111 are generally V-shaped rods, V-shaped-like rods, arc-shaped rods or arc-shaped-like rods, which are convenient for folding and unfolding. The number of the outer wave rods 1121 is the same as or different from the number of the inner wave rods 1111. For example, the number of the inner wave rods 1111 is greater than, equal to or less than the number of the outer wave rods 1121.

[0053] In any case, at least one inner wave rod 1111 is correspondingly provided for each outer wave rod 1121, and each inner wave rod 1111 is within the coverage range of the corresponding outer wave rod 1121. The inner wave rod 1111 is nested in the corresponding outer wave rod 1121, but they are not in 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 in the same annular wave band 112A is the same as the number of inner wave rods 1111, so that each outer wave rod 1121 is correspondingly provided with one inner wave rod 1111, with a simple structure and good use effect. After the inner wave rod 1111 is provided, when the pocket 400 contracts and expands, the influence on the inner skirt 220 can be reduced, and the risk of the inner skirt 220 being pulled and broken can be lowered. In addition, the inner wave rod 1111 can also better support the pocket 400, making it easier for the reflux liquid to enter the pocket 400, and improving the effect of preventing paravalvular leakage.

[0054] Actually, when the outer skirt 210 is connected to the inner skirt 220 along the outer layer structure 112, one or more pockets 400 can be formed. The number of pockets 400 is set according to actual needs. Generally, the pockets 400 are defined in the areas where paravalvular leakage is likely to occur, and the pockets 400 can be set or not set in other areas where paravalvular leakage is not likely to occur. Further, the outer skirt 210 can be covered at the positions where the pockets 400 are not set, but the outer skirt 210 is not connected to the inner skirt 220 to form a pocket 400, or the outer skirt 210 can also not be provided at the positions where the pockets 400 are not set. Therefore, the coverage range of the outer skirt 210 can be set according to needs. In addition, when multiple pockets 400 are formed, the sizes of the multiple pockets 400 can be the same or different. For example, large pockets 400 are selected in the areas where paravalvular leakage is likely to occur, and small pockets 400 or no pockets 400 can be selected in other areas. In the following description, the formation of multiple pockets 400 is used for exemplary illustration.

[0055] As Figure 2b shown, in an embodiment, the outer skirt 210 covers all the outer wave rods 1121 and inner wave rods 1111 and forms multiple pockets 400 of the same size, and these pockets 440 are independently arranged with respect to each other. Among them, the outer skirt 210 is sewn together with the inner skirt 220 along all the outer wave rods 1121, and in this way, multiple independent pockets 400 are formed, and two opposite sides of each pocket 400 are sewn on the outer wave rod 1121.

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

[0057] The skirt 200 can be prepared from 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 junction of the flange portion 110 and the myocardium, reduce blood dynamic flushing, and increase the thrombus formed in this 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 diameter on the outer skirt 210 is 90 to 160 microns, and the pore diameter on the inner skirt 220 is less than 90 microns. Specifically, the material of the outer skirt 210 is selected as a polymer material with a larger porosity, especially a knitted fabric, and the knitted fabric includes but is not limited to Knited PET (knitted PET) material. After setting the outer skirt 210 to have a larger porosity, blood (especially including red blood cells) can be allowed to enter the fitting area between the flange portion 110 and the myocardium, but large thrombi are prevented from leaving this fitting area. Here, the fitting area filled with a large amount of thrombi can be used as a potting for the internal structure of the artificial valve (including the inner layer structure 111, the inner skirt 220, and the artificial valve leaflet 300) to further stabilize the artificial valve. In addition, the material of the inner skirt 220 is selected as a polymer material or a pericardial tissue material with a smaller porosity, and the polymer material is, for example, but not limited to PET material, to better prevent blood leakage.

[0058] As Figure 1 、 Figure 4 and Figure 5 shown, in an embodiment, the inner layer wave rods 1121 are arranged parallel to the central axis of the stent body 120, so that the inner layer wave rods 1121 extend in a direction away from the outflow end 120B along the central axis. At this time, the outer layer wave rods 1121 are inclined outward relative to the inner layer wave rods 1111, so as to radially stagger the inner layer structure 111 and the outer layer structure 112.

[0059] AsFigure 3a and Figure 3b As shown, in another embodiment, the inner wave rod 1111 is bent into an arc shape towards the outer wave rod 1121, thereby increasing the support of the skirt 200 and reducing the difficulty of sewing the skirt 200. At this time, the inner wave rod 1111 forms an angle θ with the direction of the central axis. The angle θ does not exceed 90°, preferably, the angle θ is 30° - 90°, more preferably, the angle θ is 40° - 60°, so as to avoid entering the annular surface where the outer structure 112 is located due to too large an angle, and prevent the support effect from being reduced due to too small an angle. Moreover, when the pocket 400 contracts and expands, the arc-shaped inner wave rod 1111 can also reduce the force between the inner skirt 220 and the inner wave rod 1111, reducing the risk of the inner skirt 220 being pulled and broken.

[0060] As Figure 1 and Figure 3a shown, in one embodiment, there is no direct connection between the inner wave rod 1111 and the outer wave rod 1121. As Figure 4 shown, in another embodiment, at least part of the inner wave rod 1111 is connected to the corresponding position of the outer wave rod 1121 through a connecting rod 113. Practically, a connecting rod 113 connected to the inner wave rod 1111 can be added at the top of the inner wave rod 1111. The connecting rod 113 can better support the pocket 400, making it easier for the reflux liquid to enter the pocket 400, and further improving the effect of preventing paravalvular leakage. The connecting rod 113 is a rigid structure or a flexible structure. A rigid structure means that the connecting rod 113 is not easily stretched or deformed, nor is it easily bent, and a flexible structure means that the connecting rod 113 is easily stretched, deformed and bent. In view of the fact that the outer wave rod 1121 needs to be close to the myocardium at the native valve annulus and thus has a large movement amplitude during cardiac pulsation, for this reason, the connecting rod 113 is preferably a flexible structure to reduce the influence on the inner wave rod 1111. The connecting rod 113 can be prepared from a flexible material, and / or has flexibility in structure. In practice, the connecting rod 113 can be made into a flexible structure by at least one method. The following is a demonstration.

[0061] As Figure 5 shown, in a demonstration example, the connecting rod 113 has a wavy structure, enabling it to stretch. As a variant, a spring replaces the wavy structure. In other embodiments, the connecting rod 113 is prepared from a flexible material (including elastic materials). 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 part 120. The flexible connecting rod 113 can reduce the movement transmitted from the outer wave rod 1121 to the inner wave rod 1111, which is beneficial to maintaining the orifice size and morphological stability of the artificial valve, being beneficial to sealing and increasing anchoring.

[0062] As described above, the present invention provides a valve stent and an artificial valve, which optimize the flange portion into an inner structure and an outer structure. The effect is that, without over-sizing design, it can effectively prevent paravalvular leakage and avoid risks such as myocardial injury and outflow tract obstruction. At the same time, the inner structure and the outer structure are wrapped by a skirt to form a pocket to prevent paravalvular leakage. By means of the pocket being bulged by the refluxing liquid to fill the gap between the flange and the myocardium, the effect of preventing paravalvular leakage is good, and it can also be applicable to native valve annuli of different shapes, with good flexibility. In addition, this two-layer flange can be obtained by cutting and shaping a single hollow pipe, which is relatively easy to implement in terms of technology, simplifies the manufacturing process, and reduces the manufacturing cost.

[0063] It should be noted that for those of ordinary skill in the art in the technical field, without departing from the disclosed content of the present invention, several improvements and supplements can still be made, and these improvements and supplements should also be regarded as the protection scope of the present invention. For those skilled in the art, without departing from the spirit and scope of the present invention, any equivalent changes such as minor modifications, decorations, and evolutions made by using the above-disclosed technical content are 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 still fall within the scope of the technical solution of the present invention.

Claims

1. An artificial valve, comprising a skirt, artificial valve leaflets and a valve stent, wherein the artificial valve leaflets are arranged inside the valve stent and are connected to the skirt and the valve stent, and is characterized in that, The valve stent includes a flange portion and a main body portion. The flange portion is connected to the inflow end of the main body portion. The flange portion includes an inner layer structure and an outer layer structure arranged from the inside to the outside. Both the outer layer structure and the inner layer structure are arranged around the central axis of the main body portion. 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 portion forms a three-dimensional structure in a way of internal and external staggered layers. The skirt includes an inner skirt and an outer skirt. The inner skirt is arranged on the inner side of the valve stent, and 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 defines a pocket opening, and the pocket opening is located on the outer side of the valve stent and is arranged towards the outflow end of the main body portion.

2. The artificial valve according to claim 1, wherein, The outer layer structure includes at least one layer of annular wave bands. 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 sequentially arranged along the circumferential direction 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 sequentially arranged along the circumferential direction of the inflow end. At least one inner wave rod is correspondingly arranged for each outer wave rod, and each inner wave rod is within the coverage range of the corresponding outer wave rod.

3. The artificial valve according to claim 2, wherein, 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 one inner wave rod is correspondingly arranged for each outer wave rod.

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

5. The artificial valve according to claim 2, wherein, The inner wave rods are bent into an arc shape towards the outer wave rods, so that an included angle is formed between the inner wave rods and the direction of the central axis, and the included angle is 30°-90°.

6. The artificial valve according to claim 2, wherein, The outer layer structure includes multiple layers of the annular wave bands, and adjacent annular wave bands are connected through connecting ribs.

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

8. The artificial valve according to claim 1, characterized in that, The outer skirt surrounds the outside of the flange portion, and the pocket opening is defined at the starting edge position of the flange portion for fitting the native tissue. Or, a stent annulus is defined at the connection of the main body portion and the flange portion. The outer skirt surrounds the outside of the stent annulus and the outside of the flange portion, and the outer skirt is disconnected at the target position of the flange portion for fitting the native tissue to define the pocket opening.

9. The artificial valve according to claim 1 or 8, characterized in that, When the outer skirt is connected to the inner skirt along the outer layer structure, a plurality of the pockets are formed, and the sizes of the plurality of pockets are the same or different.

10. The artificial valve according to claim 1 or 8, characterized in that, The porosity of the outer skirt is greater than the porosity of the inner skirt.

11. The artificial valve according to claim 1 or 8, characterized in that, The outer structure includes at least one annular band, the annular band includes a plurality of outer wave rods connected to the inflow end, all the outer wave rods on the annular band are sequentially arranged along the circumferential direction of the inflow end, the inner structure includes a plurality of inner wave rods connected to the inflow end, all the inner wave rods are sequentially arranged along the circumferential direction 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 stitched and connected on the outer wave rods to define the pocket.

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