Valve stent, valve prosthesis and application of valve stent and valve prosthesis to preparation of medical instrument

Abstract

The invention discloses a valve stent, a valve prosthesis and application of the valve stent and the valve prosthesis to preparation of medical instruments. The valve stent comprises an inner-layer stent body and an outer-layer stent body, the outer-layer stent body is of a hollow net-shaped structure with the two ends open and comprises an outer stent body and a woven structural part, the outer stent body comprises a main supporting part and a secondary supporting part which are sequentially connected in the axial direction, and the secondary supporting part is provided with a self-adaptive area; the woven structural part is fixed on the secondary supporting part and covers the self-adaptive area; the supporting strength of the woven structural part is smaller than that of the outer frame body. The inner-layer frame body is of a cylindrical structure with two open ends; the outer-layer frame body is arranged outside the inner-layer frame body in a sleeving manner and is fixedly connected with the inner-layer frame body. The valve support is stable in structure, and on the premise that a good radial supporting effect is kept, damage to native tissue of a patient is small.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and in particular to the field of minimally invasive implantable medical devices. Background Art

[0002] The heart may develop a variety of valvular diseases due to congenital or acquired reasons. These valvular diseases will directly or indirectly affect people's physical and mental health. When the heart valve disease is serious, artificial valve prosthesis is needed to replace the diseased natural valve. At present, percutaneous minimally invasive surgery is developing rapidly. This technology can enter the body through a catheter, release the valve prosthesis, and achieve the effect of treating valvular diseases. This valve prosthesis has become a research hotspot and has huge market potential.

[0003] At present, valve prostheses that enter the human body through catheters use radial interference to prop up the diseased valve in order to effectively avoid paravalvular leakage. However, valve prostheses with radial interference are prone to interfere with the patient's native tissue, causing harm to the patient and leading to complications such as left ventricular outflow tract obstruction or atrioventricular conduction abnormalities. Summary of the invention

[0004] The object of the present invention is to provide a valve stent or valve prosthesis with a stable structure, which reduces damage to the patient's native tissue, prevents paravalvular leakage, and improves the treatment effect.

[0005] In order to achieve the above objectives, one aspect of the present invention provides a valve stent, which includes an inner frame and an outer frame;

[0006] The outer frame is a hollow mesh structure with openings at both ends, including an outer frame body and a braided structure, wherein the outer frame body includes a main support portion and a secondary support portion connected in sequence in the axial direction, the secondary support portion is provided with an adaptive zone, and the braided structure is fixed to the secondary support portion and covers the adaptive zone; the support strength of the braided structure is less than the support strength of the outer frame body;

[0007] The inner frame is a cylindrical structure with openings at both ends; the outer frame is sleeved outside the inner frame and fixedly connected to the inner frame.

[0008] In some embodiments, the main support portion includes a curved structure connected to the secondary support portion and an inclined structure that converges from the top of the curved structure toward the axis of the outer frame body;

[0009] The secondary support portion is a cylindrical structure with openings at both ends, and the adaptive zone is opened on the circumferential side wall of the secondary support portion; the circumferential length of the adaptive zone does not exceed one half of the circumference of the secondary support portion;

[0010] In some embodiments, the ratio of the circumferential length of the adaptive zone to the circumference of the secondary support portion is 1:6-1:3.

[0011] In some embodiments, the axial length of the adaptive zone does not exceed the axial length of the secondary support portion.

[0012] In some embodiments, the ratio of the axial length of the adaptive zone to the axial length of the secondary support portion is 1:6-1:1.

[0013] In some embodiments, the braided structural member is fixedly connected to the outer frame body.

[0014] In some embodiments, the fixed connection method is to connect through a fixing member or to form the braided wire of the braided structure member by winding around the edge portion of the adaptive region of the outer frame body.

[0015] In some embodiments, the braided structure is formed from braided wires of nickel-titanium alloy.

[0016] In some embodiments, the inner frame includes a first corrugated structure portion, a main body portion, and a second corrugated structure portion connected to each other, and the wave crests of the first corrugated structure portion and the second corrugated structure portion are both far away from the main body portion.

[0017] In some embodiments, when the main support portion is a corrugated structure, the crest of the first corrugated structure or the second corrugated structure of the inner frame body abuts against the crest of the corrugated structure of the main support portion of the outer frame body.

[0018] In some embodiments, the ratio of the diameter of the main portion of the inner frame to the diameter of the secondary support portion of the outer frame is 1:2-3:5.

[0019] In some embodiments, the diameter of the secondary support portion of the outer frame body is larger than the diameter of the valve annulus.

[0020] In some embodiments, the diameter of the secondary support portion of the outer frame body is 1.1-1.3 times the diameter of the valve ring, and more preferably 1.1-1.2 times.

[0021] In some embodiments, an anchoring unit is provided on the outer frame, and the anchoring unit protrudes in a direction away from the valve stent.

[0022] In some embodiments, one end of the anchoring unit is connected to the bottom of the inner surface of the outer frame, and the other end first extends out of the outer frame to one side away from the valve stent, and then bends to extend to one side of the valve stent.

[0023] In some embodiments, the anchoring unit is a hook structure.

[0024] In some embodiments, the hook structure is an elastic structure.

[0025] In some embodiments, the outer frame is provided with needle punctures.

[0026] In some embodiments, one end of the needle is connected to the outer surface of the outer frame, and the other end is inclined toward the outside of the valve stent.

[0027] Another aspect of the present invention provides a valve prosthesis, which includes the aforementioned valve stent, a suture membrane and a valve leaflet, wherein the suture membrane is disposed around the valve stent to form a sealing structure.

[0028] In some embodiments, the leaflets are fixedly connected to the suture membrane at the side wall of the inner frame.

[0029] In some embodiments, when the valve prosthesis is in an operating state, the portion of the valve stent-filled braided structural member is directed toward the left ventricular outflow tract or the atrioventricular node.

[0030] Another aspect of the present invention is the use of the aforementioned valve stent or valve prosthesis for preparing a medical device.

[0031] In some embodiments, the medical device is a heart valve prosthesis.

[0032] In some embodiments, the medical device is a mitral valve prosthesis or a tricuspid valve prosthesis.

[0033] Compared with the prior art, the valve prosthesis of the present invention has the following beneficial effects:

[0034] 1. The valve stent of the present invention adopts a double-layer structure of an inner stent and an outer stent. The inner stent is used to maintain the stability of the valve stent, and the outer stent is used to buffer the extrusion force generated when the heart beats and squeezes. After being installed on the native valve ring, it has a good radial support effect, and the valve stent has good stability;

[0035] 2. The adaptive zone in the valve stent of the present invention adopts a braided structural member with a support strength less than that of the outer frame body. Compared with the valve frame, the adaptive zone has better flexibility and can adaptively fit the patient's native tissue when it contacts the patient's native tissue, thereby avoiding compression with the native tissue;

[0036] 3. The valve stent of the present invention adopts a radial interference design to form a good fit between the valve prosthesis and the native valve ring, effectively avoiding paravalvular leakage;

[0037] 4. The combined structural design of the inner and outer stents of the present invention prevents the inner stent from being affected when the outer stent is squeezed by the beating of the heart, thereby maintaining the normal opening and closing function of the valve leaflets, thereby achieving a better treatment effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 is a schematic structural diagram of the outer frame in Example 1;

[0039] Figure 2 is a schematic structural diagram of the valve stent in Example 1;

[0040] Figure 3 is a top view of the valve stent in Example 1;

[0041] Figure 4 It is a bottom view of the secondary support portion of the outer frame body in Example 1;

[0042] Figure 5 This is a schematic diagram of the unfolded structure of the secondary support portion of the outer frame body in Example 1;

[0043] Figure 6 This is a schematic diagram of the unfolded structure of the braided structural member filled with the secondary support portion of the outer frame body in Example 1;

[0044] Figure 7 is a schematic structural diagram of the inner frame in Example 1;

[0045] Figure 8 is a top view of the valve prosthesis in Example 2;

[0046] Fig. 9 is a schematic structural diagram of the valve prosthesis in Example 2;

[0047] Fig.10 This is a schematic diagram of the positional relationship between the hook and the native tissue in Example 2;

[0048] Fig.11 It is a schematic diagram of the installation structure of the valve prosthesis in Example 2 on the tricuspid valve ring;

[0049] Fig.12 It is a schematic diagram of the installation structure of the valve prosthesis on the mitral valve ring in Example 2;

[0050] Fig.13 It is a schematic diagram of the structure of a mesh support in the prior art.

[0051] Reference numerals:

[0052] 1. Outer frame; 11. Outer frame body; 111. Secondary support part; 112. Main support part; 1121. Wave crest; 113. Connection hole; 114. Hook; 115. Adaptive zone; 12. Braided structure; 2. Inner frame; 21. Main part; 22. Wave structure part; 221. First wave structure; 2211. Wave crest; 222. Second wave structure; 3. Suture membrane; 4. Leaflet assembly; 5. Native leaflet; 6. Atrial septum; 7. Tricuspid valve ring; 8. Atrioventricular node; 9. Mitral valve ring; 10. Left ventricular outflow tract; 100. Aortic stent; 200. Valve stent; 300. Right ventricular outflow tract stent. DETAILED DESCRIPTION

[0053] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific implementation disclosed below.

[0054] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0055] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of the specification are only used to match the contents recorded in the specification so as to facilitate the understanding and reading of technical personnel in this field, and are not used to limit the conditions under which the present application can be implemented. Therefore, they have no substantive technical significance. Any structural modification, change in proportional relationship or adjustment of size, without affecting the effects and purposes that can be achieved by the present application, should fall within the scope of the technical content disclosed in the present application.

[0056] It should be clear that the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0057] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0058] It should be noted that the directional words such as "upper", "lower", "left", and "right" described in the embodiments of the present application are described at the angles shown in the accompanying drawings and should not be understood as limiting the embodiments of the present application. In addition, in the context, it is also necessary to understand that when it is mentioned that an element is connected to another element "upper" or "lower", it can not only be directly connected to another element "upper" or "lower", but also indirectly connected to another element "upper" or "lower" through an intermediate element.

[0059] The orientation or position relationship indicated by the terms "bottom", "top", "lower", "inside", "outside", etc. is based on the orientation or position relationship shown in the drawings and is only for the convenience of describing the present invention and simplifying the description. It does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0060] Unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0061] As used in this specification, the singular forms "a", "an", and "the" include plural referents unless the context clearly indicates otherwise. The terms "first", "second", and "third" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance. The term "or" is generally used in a sense including "and / or" unless the context clearly indicates otherwise.

[0062] As used herein, the term "axial direction" refers to the axial direction of the stent body, and "above" refers to directly above.

[0063] As used herein, the term "abutting" means in direct physical contact with each other.

[0064] The artificial heart valve stent provided by the present invention is configured to form various artificial heart valve products of different models by setting different diameters of the outer frame 1 and the inner frame 2, different models of artificial valve leaflet components 4 and suture membranes 3 and other structures.

[0065] The invention discloses a valve stent, which comprises an inner frame and an outer frame. The outer frame is sleeved on the outer side of the inner frame and fixedly connected with the inner frame.

[0066] Outer frame

[0067] In the present invention, the outer frame is a hollow mesh structure with openings at both ends, and the outer frame body includes a main support part and a secondary support part connected in sequence in the axial direction, the secondary support part is a cylindrical structure with openings at both ends, and an adaptive zone is provided on the circumferential side wall of the secondary support part, a woven structure is fixed in the adaptive zone, and the woven structure covers the entire adaptive zone. The main support part includes a curved structure and an inclined structure connected in sequence in the axial direction. The bottom of the curved structure is connected to the secondary support part, and the inclined structure converges from the top of the curved structure toward the axial center direction of the outer frame body.

[0068] In some embodiments, the shape of the adaptive zone can be rectangular or approximately rectangular. The size of the adaptive zone can be selected with reference to the size of the native tissue in the human body.

[0069] In some embodiments, the adaptive zone is a frame-free region of the secondary support portion, and the frame-free region is preferably formed by cutting an outer layer frame.

[0070] External frame

[0071] In the axial direction, the secondary support part in the outer frame body is located at the bottom, and the main support part is located at the top. The main force-bearing part of the main support part is the curved structure, that is, the curved structure provides the maximum support force of the entire outer frame body. The maximum diameter of the curved structure is the maximum support diameter of the valve stent.

[0072] The maximum support diameter of the main support portion of the outer frame body is greater than the diameter of the native valve ring, forming a radial interference structure relative to the native valve ring, so that the valve prosthesis using the valve stent can form a good fit with the native valve position.

[0073] In some embodiments, the maximum support diameter of the main support portion of the outer frame body is 1.1-1.3 times the diameter of the valve ring, and more preferably 1.1-1.2 times.

[0074] In some embodiments, the angle between the inclined structure of the main support and the axis of the outer frame is less than 60 degrees, for example, it can be 10-45 degrees, 10-30 degrees or 30-45 degrees. The angle of the inclined structure relative to the axis of the outer frame can be adaptively selected according to the spacing between the main support and the secondary support and the connection method.

[0075] In some embodiments, a connection hole is provided above the inclined structure, through which a traction device of the valve prosthesis is connected or other parts of the prosthesis are connected through the fixing member.

[0076] In some embodiments, the main supporting portion is a wave-shaped structure as a whole.

[0077] In some embodiments, a connection hole is provided above the crest of the wave-shaped structure of the main support portion.

[0078] Optionally, a connection hole may be provided above one or more crests of the wave-shaped structure.

[0079] In some embodiments, the main support portion and the secondary support portion may be integrally connected.

[0080] The material forming the outer frame body can be made of metals such as nitinol, titanium alloy, cobalt-chromium alloy, MP35n, 316 stainless steel, L605, Phynox / Elgiloy (cobalt-chromium-nickel alloy), platinum-chromium, etc., or other biocompatible metals known to those skilled in the art.

[0081] Alternatively, the exoframe body may also be made of an elastically or plastically deformable material, such as balloon expandable, or may be a shape memory alloy that responds to temperature changes to transition between a contracted delivery state and an expanded deployed state.

[0082] In some embodiments, the outer frame body is manufactured by cutting nickel-titanium alloy tubes, the outer diameter of the tubes is 4-50 mm, and the diameter size after shaping is selected according to actual needs.

[0083] Adaptive zones and braided structures

[0084] In the present invention, the circumferential length of the adaptive zone does not exceed half of the circumference of the secondary support portion, for example, does not exceed one third of the circumference of the secondary support portion.

[0085] In some embodiments, the ratio of the circumferential length of the adaptive zone to the circumference of the secondary support portion is 1:6-1:3, for example, 1:6-1:5, 1:6-1:4 or 1:4-1:5.

[0086] In some embodiments, the axial length of the adaptive zone does not exceed the axial length of the secondary support portion.

[0087] In some embodiments, the ratio of the axial length of the adaptive zone to the axial length of the secondary support portion is 1:6-1:1, for example, it can be 1:5-1:1, 1:4-1:1, 1:3-1:1, 1:6-1:2, 1:6-1:3, 1:6-1:4 or 1:5-1:4.

[0088] In some embodiments, the braided structure may be in a grid shape, a diamond shape, a zigzag shape, or a zigzag shape.

[0089] In some embodiments, under the condition that the outer frame provides radial support to the native valve annulus, the material forming the braided structure may be nickel-titanium alloy, stainless steel or a polymer material.

[0090] In some embodiments, the braided structure is formed from braided wires of nickel-titanium alloy.

[0091] The woven structural member is fixedly connected to the secondary support structure at the edge of the adaptive zone.

[0092] The braided structure and the secondary support portion may be connected by welding, riveting or bonding, or the edge of the braided structure may be tied to the edge of the adaptive zone by a flexible line. In another implementation, the braided structure may be pre-sewn on the suture film of the valve prosthesis, and when the suture film is surrounded on the outer frame body, the braided structure just covers the area formed by the adaptive zone.

[0093] The inventor of the present invention has found that in the prior art, the valve stent is usually a single-layer hollow mesh structure. For example, in Chinese invention patent application CN200710007443.3, a replacement device is disclosed, which is a mesh stent made of memory metal material. Fig.13 The mesh stent in this solution is divided into three parts: an aortic stent 100 with a larger diameter, a valve stent 200 with a smaller diameter, and a right ventricular outflow tract stent 300 with a moderate diameter, so that the stent can be in line with the characteristics of the heart structure after being in place and is not easy to be misplaced. In this type of single-layer mesh structure, the stent 300 is used to provide radial support force to enable the mesh stent to be firmly embedded in the native valve ring.

[0094] If the support 300 is considered to structurally avoid the native structure at a specific position, the technical means disclosed in the prior art include: 1. Enlarging the grid of the area corresponding to the native structure after the support 300 reaches the predetermined position; 2. Forming a gap in the area corresponding to the native structure after the support 300 reaches the predetermined position to avoid the native structure.

[0095] When the above two solutions are adopted, when the stent 300 provides radial support force, the radial stress in the enlarged mesh area will become weaker, or the radial stress in the vacant area will be missing. Since the stent 300 is installed on the aortic valve, the scouring force of the blood flow there is relatively large. If the radial support force of the stent 300 becomes weak, it will be washed away by the blood and then fall off. Therefore, in the existing single-layer frame structure, technical personnel in this field usually do not consider increasing the mesh or opening vacant areas to avoid the original structure.

[0096] In some existing valve frame structures, the valve stent also has a double-layer structure using an inner stent and an outer stent. Among them, the inner stent is mainly used to carry artificial valve leaflets and has strong rigidity and small diameter, so as to reduce the area of ​​artificial valve leaflets and reduce the height required for the opening and closing movement of the valve leaflets; the outer stent is relatively weak in rigidity and has a larger diameter, and is used to prevent paravalvular leakage. The anchoring structure is connected to the inner stent, and the anchoring force that prevents the movement of the prosthetic valve is mainly borne by the inner stent with stronger rigidity, thereby increasing the life of the stent. Since it is necessary to prevent paravalvular leakage, the structure of the outer stent will also refer to the structural characteristics of the above-mentioned single-layer hollow mesh structure, and try to make the mesh uniform so that it has a more stable and stable radial support force to avoid paravalvular leakage. Therefore, those skilled in the art usually do not consider increasing the mesh of the outer stent or opening a vacant area to avoid the native structure.

[0097] In the present application, the inventor adopts the structure of an inner frame and an outer frame, and creatively designs the outer frame into two parts: a main support part and a secondary support part. The main support part is mainly used to play a radial support role, and the secondary support part is used to extend the main support part. Due to the existence of the main support part, the role of the secondary support part can be further expanded. Therefore, an adaptive zone that is adapted to the native structure area of ​​the human body is opened up on the secondary support part, and a woven structural member with smaller support strength is fixed in the adaptive zone. The support strength of the woven structural member is less than that of the outer frame. Compared with the valve frame, the adaptive zone has better flexibility and can adaptively fit the patient's native tissue when it contacts the patient's native tissue, thereby avoiding compression with the native tissue.

[0098] It should be noted that in the embodiments of the present application, if the adaptive zone is too large, that is, the area of ​​the braided structural member is too large, the overall stability of the stent will be affected due to the low support strength of the braided structural member itself. If the adaptive zone is too small, that is, the area of ​​the braided structural member is too small, the effect of avoiding native tissue will be affected. The selection criteria can refer to the size of the pre-avoided native tissue.

[0099] In the present invention, the braided structural member has a relatively low support strength, which can be a plurality of ways or combinations such as a sparser mesh, finer mesh bars, and a softer material. The braided structural member has a relatively low structural strength and is more flexible when subjected to radial force. The braided structural member is easier to deform relative to the external frame body to avoid squeezing the native tissue, and can also adapt to the shape of the atrioventricular valve to reduce peripheral leakage.

[0100] In one embodiment, when the valve prosthesis is in an operating state, the portion of the filling braided structure faces the left ventricular outflow tract or the atrioventricular node.

[0101] Inner frame

[0102] The inner frame is a cylindrical structure with openings at both ends.

[0103] In some embodiments, the inner frame is cylindrical or approximately cylindrical, or a cylindrical structure with trumpet-shaped structures at both ends, or a cylindrical structure with one end being straight cylindrical and the other end being trumpet-shaped.

[0104] In some embodiments, the inner frame includes a first corrugated structure portion, a main body portion, and a second corrugated structure portion connected to each other, and the wave crests of the first corrugated structure portion and the second corrugated structure portion are both far away from the main body portion.

[0105] In some embodiments, when the main support portion is a corrugated structure, the crest of the first corrugated structure or the second corrugated structure of the inner frame body abuts against the crest of the corrugated structure of the main support portion of the outer frame body.

[0106] In some embodiments, the main body of the inner frame is provided with a plurality of hollows, which may be circular, grid-shaped, diamond-shaped or other patterns.

[0107] The material forming the inner frame can be made of metals such as nitinol, titanium alloy, cobalt-chromium alloy, MP35n, 316 stainless steel, L605, Phynox / Elgiloy (cobalt-chromium-nickel alloy), platinum-chromium, etc., or other biocompatible metals known to those skilled in the art.

[0108] Alternatively, the inner frame may also be made of an elastically or plastically deformable material, such as balloon expandable, or may be a shape memory alloy that responds to temperature changes to transition between a contracted delivery state and an expanded deployed state.

[0109] In some embodiments, the inner frame is manufactured by cutting nickel-titanium alloy tubes, the outer diameter of the tubes is 4-50 mm, and the diameter size after shaping is selected according to actual needs.

[0110] Valve stent

[0111] The valve stent comprises an inner frame and an outer frame.

[0112] The inner frame is sleeved in the outer frame and fixedly connected to the outer frame.

[0113] In some embodiments, the inner frame and the outer frame can be connected by fixing parts, or the inner frame and the outer frame can be connected by welding, riveting, or crimping.

[0114] In one embodiment, the inner frame and the outer frame are connected by binding with a flexible binding belt (such as metal or non-metal wire).

[0115] The diameter of the main part of the inner frame body is not less than half of the diameter of the secondary support part of the outer frame body.

[0116] In some embodiments, the ratio of the diameter of the main portion of the inner frame to the diameter of the secondary support portion of the outer frame is 1:2-3:5, for example, 1:2-4:5 or 3:5-4:5.

[0117] Anchoring units, needle punctures and development points

[0118] In some embodiments, an anchoring unit is provided on the outer frame, and the anchoring unit protrudes in a direction away from the valve stent.

[0119] In some embodiments, one end of the anchoring unit is connected to the bottom end of the inner surface of the outer frame, and the other end first extends out of the outer frame to one side away from the valve stent, and then bends to extend to one side of the valve stent.

[0120] In some embodiments, the anchoring unit is a hook structure.

[0121] In some embodiments, the hook structure is an elastic structure.

[0122] Optionally, a plurality of hooks are arranged in the circumferential direction of the outer frame.

[0123] In some embodiments, the surface of the hook and the connection portion with the outer frame are further provided with a coating layer, and the coating layer can be provided in the form of coating, woven cloth sewing, etc.

[0124] Optionally, the material of the coating layer may be a material with good biocompatibility and easy endothelialization, such as PET, PTFE, ePTFE, PU, ​​or a biological tissue material such as porcine pericardium or bovine pericardium.

[0125] In some embodiments, the outer frame is provided with acupuncture needles, which are used for pinning and fixation, and can more stably fix the valve stent or the prosthesis prepared by the stent.

[0126] In some embodiments, one end of the needle is connected to the outer surface of the outer frame, and the other end is inclined toward the outside of the valve stent.

[0127] In one embodiment, the outer frame is provided with a plurality of needles, which are connected to the outer frame and inclined toward the radial outer side of the stent.

[0128] In some embodiments, a developing point is provided on the hook claw.

[0129] In other embodiments, developing points are provided around the filling portion of the braided structure to facilitate monitoring of the orientation of the braided structure during the process of implanting the stent.

[0130] Valve prosthesis

[0131] According to another aspect of the present invention, a valve prosthesis is provided, comprising a valve stent, a suture membrane and a valve leaflet, wherein the suture membrane is disposed around the valve stent to form a sealing structure.

[0132] In some embodiments, the material of the suture membrane can be selected from materials with good biocompatibility and easy endothelialization such as PET (polyethylene terephthalate), PTFE (polytetrafluoroethylene), ePTFE (expanded polytetrafluoroethylene), PU (polyamide), or biological tissue materials such as porcine pericardium and bovine pericardium.

[0133] Under the condition that the function of preventing blood flowing through the valve prosthesis from flowing out from the side wall of the outer frame is met, the suture membrane can be a grid shape with dense grid gaps made of yarns such as PET, PTFE, ePTFE, PU, ​​etc.

[0134] Optionally, the suture membrane may be connected to the outer side wall or the inner side wall of the stent, for example, by tying with a non-metallic wire.

[0135] In some embodiments, the leaflets are fixedly connected to a suture membrane wrapped around the side wall of the inner frame.

[0136] Optionally, the leaflets are sutured to a suture membrane wrapped around the side walls of the inner frame.

[0137] The valve prosthesis includes at least two artificial leaflets, the number of which is the same as or different from that of the native leaflets, one end of which is stably connected to the suture membrane on the side wall of the inner frame, and the other end of which is a free end. In the working state, the artificial leaflets replace the native leaflets to open and close the blood channel.

[0138] The materials used to make the leaflet assembly include biological tissue materials or synthetic materials. For example, the biological tissue material can be any one of bovine pericardium, sheep pericardium, porcine pericardium or horse pericardium tissue, and the synthetic material can be polyurethane, polytetrafluoroethylene or silicone polyester.

[0139] The valve prosthesis has two states: a compressed state and an expanded state. Unless otherwise specified in the present invention, the characteristic descriptions are all in the expanded state.

[0140] use

[0141] The present invention provides use of the aforementioned valve stent or the aforementioned valve prosthesis for preparing medical devices.

[0142] In some embodiments, the medical device is a heart valve prosthesis.

[0143] In some embodiments, the medical device is a mitral valve prosthesis or a tricuspid valve prosthesis.

[0144] Example 1

[0145] This embodiment provides a valve stent, which includes an outer frame 1 and an inner frame 2. The outer frame 1 and the inner frame 2 are fixedly connected.

[0146] like Figure 1-3 As shown, the outer frame 1 is a hollow mesh structure with two ends open, including an outer frame body 11 and a woven structure 12, wherein the outer frame body 11 includes an integrally connected secondary support portion 111 and a main support portion 112. The outer frame body 11 is cut from a metal pipe.

[0147] like Figure 1 As shown, the secondary support part 111 is in a grid structure, cylindrical or approximately cylindrical, and the main support part 112 is formed by the top of the outer frame body 11 being gathered inward along a straight track, which is a wave-shaped structure, and a connecting hole 113 is provided above the wave crest 1121 of the wave-shaped structure. The connecting hole 113 is used to connect the traction device of the valve prosthesis or to connect other parts of the prosthesis through the fixing member.

[0148] The angle α between the main support portion and the axis of the outer frame is less than 60 degrees.

[0149] The outer frame 1 is provided with hooks 114. There are a plurality of hooks 114 evenly arranged in the circumferential direction of the outer frame 1.

[0150] like Figure 4 and Figure 5 As shown, the lower portion of the secondary support portion 111 has an adaptive region 115 .

[0151] The shape of the adaptive area can be rectangular or approximately rectangular, such as Figure 5 As shown, the adaptive zone 115 is rectangular, the axial length a1 of the adaptive zone 115 does not exceed the axial length a2 of the secondary support portion 111, and the ratio of the circumferential length b1 of the adaptive zone 115 to the circumference b2 of the secondary support portion 111 is 1:6-1:2. If the adaptive zone is too large, the stability of the outer frame will be affected, and if it is too small, the effect of avoiding native tissue will be affected.

[0152] Specifically, the ratio of the axial length a1 of the adaptive zone to the axial length a2 of the secondary support portion may be 1:6-1:1; the ratio of the circumferential length b1 of the adaptive zone 115 to the circumferential length b2 of the secondary support portion may be 1:6-1:3.

[0153] Specifically, the adaptive zone can be approximately rectangular, the area of ​​the adaptive zone 115 does not exceed one third of the area of ​​the secondary support portion 111 of the outer frame body 11, and the ratio of the area of ​​the adaptive zone 115 to the area of ​​the secondary support portion 111 can be 1:36-1:3 or 1:6-1:3.

[0154] like Figure 2 or Figure 6 As shown, the adaptive zone 115 is fixed with a braided structure 12. The braided structure 12 is formed by bending a nickel-titanium alloy braided wire. The shape of the braided structure 12 can be a "U" shape or a "Z" shape. The structural strength of the braided structure 12 is less than that of the outer frame 1. When the braided structure 12 faces the native tissue of the human body or the blood circulation path, it adaptively avoids the blood channel to avoid strong obstruction to the blood flow.

[0155] The braided structure 12 is fixedly connected to the outer frame body 11 , and the fixed connection method may be connected by a fixing member, such as connected by a flexible binding belt, or the braided wire may be wrapped around the edge portion of the outer frame body 11 near the adaptive area 15 .

[0156] The inner frame 2 is cylindrical. Figure 7 As shown, it includes a main body 21 and a corrugated structure part 22, and the corrugated structure part includes a first corrugated structure 221 and a second corrugated structure 222. The crest 2211 of the first corrugated structure part 221 abuts against the crest 1121 of the main support part 112 of the outer frame body 11.

[0157] Specifically, the edge portions of the first corrugated structure 221 and the second corrugated structure 222 of the inner frame can expand outward into a bell-mouth structure, and the crest of the first corrugated structure 221 abuts against the crest 2211 of the main support portion 112 of the outer frame body 11. With such a structure, the outer frame 1 and the inner frame 2 can have more connection points, so the connection between the two will be more stable. Optionally, a binding connection can also be performed at the abutment to further stabilize the connection between the outer frame 1 and the inner frame 2.

[0158] The main body 21 of the inner frame 2 is provided with a plurality of hollows, which may be circular, grid-shaped, diamond-shaped or other patterns.

[0159] It can be understood that the distance between the outer frame 1 and the inner frame 2 can be adjusted by the diameter of the main part 21 of the inner frame 2. The smaller the diameter of the main part 21, the greater the distance between the outer frame 1 and the inner frame 2.

[0160] Since the placement position of the valve stent or the manufactured prosthesis at the valve ring, the shape of the inner stent and the outer stent, and the different connection relationship between the two have a great influence on the performance of the valve stent, the selection of the distance and structural setting of the inner and outer frames in the present invention is also relatively important. In the embodiment of the present invention, the diameter of the main body 21 is not less than half of the diameter of the secondary support portion 111 of the outer frame 2, and the ratio of the diameter of the main body 21 of the inner frame 2 to the diameter of the secondary support portion 111 of the outer frame body 11 is preferably 1:2-3:5. If the distance between the outer frame 1 and the inner frame 2 is too small, the radial support of the prosthesis will be unstable, deflection will occur after implantation, and the native valve ring will squeeze the inner frame, affecting the normal operation of the valve leaflet.

[0161] The forming methods of the inner layer frame and the outer layer frame include but are not limited to laser cutting, shearing and wire cutting. Compared with the single-layer valve stent, the double-layer stent has better stability. When the outer layer frame is squeezed by the beating heart, the inner layer frame is not affected, maintaining the normal opening and closing function of the valve leaflet and achieving better treatment effect.

[0162] Example 2

[0163] This embodiment provides a valve prosthesis, which can be used to replace various types of human valves, such as the aortic valve, mitral valve, tricuspid valve, etc.

[0164] The difference between this embodiment and embodiment 1 is that Figure 8 or Fig. 9 As shown, the valve prosthesis also includes a suture membrane 3 and a leaflet assembly 4. The suture membrane 3 wraps the valve support as a whole to form a sealing structure. The leaflet assembly 4 includes at least two leaflets, and the leaflet assembly 4 is sutured on the suture membrane wrapped at the side wall of the inner frame 2.

[0165] The suture membrane can be made of a material with good biocompatibility and easy endothelialization, such as PET, PTFE, ePTFE, PU, ​​or a biological tissue material such as porcine pericardium or bovine pericardium.

[0166] The valve leaflet assembly 4 includes at least two artificial valve leaflets, one end of which is stably connected to the suture membrane on the inner frame 2, and the other end of which is a free end. In the working state, the artificial valve leaflets replace the native valve leaflets to realize the function of opening and closing the blood channel.

[0167] When the leaflet assembly 4 is in an open state, the free ends of all the leaflets are close to the side wall of the inner frame 2, so that blood can pass through the inside of the inner frame 2; when the leaflet assembly 4 is in a closed state, the free ends of all the leaflets are away from the suture membrane of the side wall of the inner frame 2, and the free ends of two adjacent leaflets at least partially overlap.

[0168] When the valve prosthesis is implanted into the human body through the delivery system, the prosthesis is gathered in the delivery system. At the implantation position in the human body, the prosthesis automatically expands after being released or expands by balloon pressure, and is limited on the valve ring. When the implantation position is the tricuspid valve, one side of the prosthesis can be optionally pressed against the atrial septum 6, thereby completing the implantation of the valve prosthesis. At the same time, the hook 114 hooks the native valve leaflet 5 ( Fig.10 ), forming an anchoring effect on it.

[0169] The maximum support diameter of the main support portion 112 is slightly larger than the human valve annulus (can be 1.1-1.2 times the diameter of the valve annulus). When implanted in the human valve annulus, the outer layer frame 1 is stuck at the human valve annulus, so that the frame and the human valve annulus have an interference fit to achieve the limitation of the valve prosthesis at the valve annulus and avoid paravalvular leakage.

[0170] Around the native valve ring, there is an atrioventricular node located below the endocardium on the right side of the atrial septum, at the anterior inner edge of the coronary sinus ostium, the attachment edge of the tricuspid septal valve and the Todaro tendon, forming the Koch triangle. The vertex of the front part of the triangle, i.e., the junction of the anterior valve and the septal valve, is near the atrioventricular node. The atrioventricular node is an important part of the cardiac conduction system. In addition to supporting and pulling the inferior vena cava valve and the coronary sinus valve, the Todaro tendon also has a certain support and fixation effect on the myocardium below the atrial septum. Therefore, in the valve design of the original position replacement of the tricuspid valve, it is necessary to avoid squeezing and covering the Koch triangle area as much as possible.

[0171] The existing tricuspid valve design basically adopts the method of clamping the valve leaflets or grabbing the valve leaflets for anchoring. Both of these anchoring methods will pull the tendons and cause damage to the native valve leaflets. There is also the use of the atrial septum for anchoring, but this anchoring method is not reliable and also requires the additional use of the form of clamping the valve leaflets, otherwise it is easy to fall off, posing a safety hazard. In addition, there is also the risk of conduction block. Anchoring through the stent body will cause the stent to compress the conduction tissue, which will cause the risk of conduction block.

[0172] like Fig.11 As shown, in one embodiment, the valve prosthesis of the present invention is a tricuspid valve prosthesis. When the valve prosthesis is implanted, it is limited to the tricuspid valve ring 7, and its braided structure 12 is oriented toward the atrioventricular node 8, which can adapt to the atrioventricular structure to avoid compression and damage of the outer frame body 11 with greater structural strength, causing atrioventricular conduction abnormalities.

[0173] The mitral valve is the left atrioventricular valve. It is attached to the left fibrous atrioventricular ring and is formed by the folds of the endocardium. There are two valves. The one located on the anterior inner side is the anterior cusp valve, which is the boundary mark between the inflow and outflow tracts of the left ventricle; the one located on the posterolateral side is the posterior cusp valve, which is smaller. The valve is triangular in shape, with the tip facing the left ventricular cavity. The bottom edges of the two valves often fuse with each other, and sometimes a small accessory valve appears between the two valves. There are many tendinous chordae connecting the valve cusps, edges and ventricular surfaces to the papillary muscles. When the ventricle contracts, the mitral valve tightly closes the atrioventricular orifice to prevent blood from flowing back into the left atrium.

[0174] When the native mitral valve is diseased, an artificial valve can also be implanted into the body through interventional means to replace the function of the native mitral valve. The interventional means delivers the artificial valve to the implantation site through a delivery system and rivets it to the corresponding valve ring.

[0175] The left ventricular outflow tract is located on one side of the mitral valve annulus. When a valve prosthesis is implanted in the mitral valve, when the heart relaxes, the valve component is in an open state, and blood passes through the valve prosthesis into the left ventricle; when the heart contracts, the valve component is in a closed state, and blood enters the left ventricular outflow tract under the pressure of the heart.

[0176] The valve prosthesis in the prior art adopts a radial interference design. After the mitral valve prosthesis is implanted, the inflow tract of the stent is closely attached to the atrioventricular orifice at the junction of the atrium and ventricle, covering the native mitral valve ring. Therefore, after the mitral valve prosthesis is implanted, the left ventricular outflow tract has a risk of obstruction.

[0177] like Fig.12 As shown, in one embodiment, the valve prosthesis of the present invention is a mitral valve prosthesis. When the valve prosthesis is implanted, it is limited to the mitral valve ring 9. When the valve prosthesis is in working state, when the heart is in diastole, the valve leaflet assembly 4 is in an open state, and blood enters the left ventricle through the valve prosthesis; when the heart contracts, the valve leaflet assembly 4 is in a closed state, and blood enters the left ventricular outflow tract 10 under the compression of the heart. Its braided structural member 12 faces the side close to the left ventricular outflow tract 10, so that the braided structural member 12 is deformed under the extrusion effect of the native valve ring to reduce the impact on the native outflow tract, thereby facilitating the blood to flow out of the left ventricular outflow tract 10. This design, while maintaining a good radial support effect, causes less damage to the patient's native tissue, while also maintaining the overall stability of the valve prosthesis.

[0178] Obviously, many modifications and variations can be made according to the contents of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can make good use of the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A valve stent, characterized in that: It includes an inner frame and an outer frame; The outer frame is a hollow mesh structure with openings at both ends, including an outer frame body and a braided structure, wherein the outer frame body includes a main support portion and a secondary support portion connected in sequence in the axial direction, the secondary support portion is provided with an adaptive zone, and the braided structure is fixed to the secondary support portion and covers the adaptive zone; the support strength of the braided structure is less than the support strength of the outer frame body; The inner frame is a cylindrical structure with openings at both ends; the outer frame is sleeved outside the inner frame and fixedly connected to the inner frame.

2. The valve stent according to claim 1, characterized in that: The main support portion includes a curved structure connected to the secondary support portion and an inclined structure that converges from the top of the curved structure toward the axis of the outer frame body; The secondary support portion is a cylindrical structure with openings at both ends, and the adaptive zone is opened on the circumferential side wall of the secondary support portion; the circumferential length of the adaptive zone does not exceed one half of the circumference of the secondary support portion; Preferably, the ratio of the circumferential length of the adaptive zone to the circumference of the secondary support portion is 1:6-1:3; Preferably, the axial length of the adaptive zone does not exceed the axial length of the secondary support portion; Preferably, the ratio of the axial length of the adaptive zone to the axial length of the secondary support portion is 1:6-1:

1.

3. The valve stent according to claim 1 or 2, characterized in that: The braided structural member is fixedly connected to the secondary supporting portion; Preferably, the fixed connection method is to connect through a fixing member or to form the braided wire of the braided structure member by winding around the edge portion of the adaptive area of ​​the outer frame body.

4. The valve stent according to any one of claims 1 to 3, characterized in that: The braided structure is formed of nickel-titanium alloy braided wires.

5. The valve stent according to any one of claims 1 to 4, characterized in that: The inner frame comprises a first corrugated structure portion, a main body portion and a second corrugated structure portion connected to each other, wherein the crests of the first corrugated structure portion and the second corrugated structure portion are both far away from the main body portion; Preferably, when the inclined structure of the outer frame body is a wave-shaped structure, the crest of the first wave-shaped structure or the second wave-shaped structure of the inner frame body abuts against the crest of the inclined structure.

6. The valve stent according to claim 5, characterized in that: The diameter of the main part of the inner frame body is not less than half of the diameter of the secondary support part of the outer frame body; Preferably, the ratio of the diameter of the main part of the inner frame to the diameter of the secondary support part of the outer frame is 1:2-3:

5.

7. The valve stent according to any one of claims 1 to 6, characterized in that: The maximum support diameter of the main support portion of the outer frame body is greater than the valve ring diameter; Preferably, the maximum support diameter of the main support portion of the outer frame body is 1.1-1.3 times the diameter of the valve ring, and more preferably 1.1-1.2 times.

8. The valve stent according to any one of claims 1 to 7, characterized in that: The outer frame is provided with an anchoring unit, and the anchoring unit protrudes in a direction away from the valve stent; Preferably, one end of the anchoring unit is connected to the bottom of the inner surface of the outer frame, and the other end first extends out of the outer frame to one side away from the valve stent, and then bends to extend to one side of the valve stent; Preferably, the anchoring unit is a hook structure; Preferably, the hook structure is an elastic structure; Preferably, the outer frame is provided with acupuncture; Preferably, one end of the needle is connected to the outer surface of the outer frame, and the other end is inclined toward the outside of the valve stent.

9. A valve prosthesis, characterized in that: The valve stent, suture membrane and valve leaflet according to any one of claims 1 to 7 are included, wherein the suture membrane is arranged around the valve stent to form a sealing structure; Preferably, the leaflets are fixedly connected to the suture membrane at the side wall of the inner frame; Preferably, when the valve prosthesis is in a working state, the adaptive zone on the valve stent faces the left ventricular outflow tract or the atrioventricular node.

10. Use of the valve stent according to any one of claims 1 to 8 or the valve prosthesis according to claim 9 for preparing a medical device, wherein the medical device is preferably a heart valve prosthesis, more preferably a mitral valve prosthesis or a tricuspid valve prosthesis.

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