Valve stent, valve prosthesis and use for the manufacture of a medical device

Abstract

The application discloses a valve stent, a valve prosthesis and a use for preparing a medical device. The valve stent comprises an inner stent body and an outer stent body, the outer stent body is a hollow mesh structure with both ends being open, and comprises an outer stent main body and a woven structure part, wherein the outer stent main body comprises a main support part and a secondary support part which are connected in sequence in an axial direction, the secondary support part is provided with an adaptive area, and the woven structure part is fixed to the secondary support part and covers the adaptive area; the support strength of the woven structure part is smaller than that of the outer stent main body; the inner stent body is a cylindrical structure with both ends being open; and the outer stent body is sleeved outside the inner stent body and is fixedly connected with the inner stent body. The valve stent is stable in structure, and can cause less damage to the original tissue of a patient on the premise of maintaining a good radial support effect.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of medical devices, in particular to the field of minimally invasive implantable medical devices. BACKGROUND

[0002] The heart can suffer from various valvular diseases due to congenital or acquired reasons, which can directly or indirectly affect people's physical and mental health. When the heart valve disease is severe, an artificial valve prosthesis is needed to replace the diseased native valve. At present, minimally invasive surgery is rapidly developing. This technology can enter the body through a catheter to release a valve prosthesis, achieving the effect of treating valvular diseases. Such valve prostheses have become a research hotspot and have great market potential.

[0003] At present, the valve prosthesis that enters the human body through a catheter uses radial interference to prop up the diseased valve in order to effectively avoid paravalvular leakage. However, the valve prosthesis with radial interference can easily interfere with the patient's native tissue, causing harm to the patient and resulting in complications such as left ventricular outflow tract obstruction or atrioventricular conduction abnormalities. SUMMARY

[0004] The purpose of the present application is to provide a valve stent or valve prosthesis that is structurally stable, reduces harm to the patient's native tissue, and can prevent paravalvular leakage and improve treatment effectiveness.

[0005] To achieve the above purpose, in one aspect of the present application, a valve stent is provided, which includes an inner layer frame body and an outer layer frame body.

[0006] The outer layer frame body is a hollow mesh structure with open ends, including an outer frame main body and a woven structure, wherein the outer frame main 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 woven structure is fixed to the secondary support portion and covers the adaptive zone; the support strength of the woven structure is less than that of the outer frame main body.

[0007] The inner layer frame body is a cylindrical structure with open ends; the outer layer frame body is sleeved outside the inner layer frame body and is fixedly connected with the inner layer frame body.

[0008] In some embodiments, the main support portion includes a curved structure connected to the secondary support portion and an inclined structure converging from the top of the curved structure to the axial center of the outer frame main body.

[0009] The secondary support portion is a cylindrical structure with open ends, and the adaptive zone is opened on the circumferential sidewall of the secondary support portion; the circumferential length of the adaptive zone is not more than 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 is not more than 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 woven structure is fixedly connected to the outer frame body.

[0014] In some embodiments, the fixed connection is achieved by connecting a fixing member or by winding the weaving wires of the woven structure around the edge portion of the adaptive zone of the outer frame body.

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

[0016] In some embodiments, the inner frame body comprises a first wave-shaped structure portion, a main body portion, and a second wave-shaped structure portion connected in sequence, and the wave crests of the first and second wave-shaped structure portions are both away from the main body portion.

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

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

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

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

[0021] In some embodiments, the outer frame body is provided with an anchoring unit, which protrudes towards the 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 body, and the other end extends out of the outer frame body towards the side away from the valve stent and then bends towards the side of the valve stent.

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

[0024] In some embodiments, the hook structure is a resilient structure.

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

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

[0027] Another aspect of the present application provides a valve prosthesis, which comprises the aforementioned valve stent, a suture membrane and valve leaflets, and the suture membrane surrounds the valve stent to form a sealed structure.

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

[0029] In some embodiments, when the valve prosthesis is in a working state, the part of the valve stent filled with the woven structure member is directed towards the left ventricular outflow tract or the atrioventricular node.

[0030] Another aspect of the present application provides 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 application has the following beneficial effects:

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

[0035] 2. The adaptive zone in the valve stent of the present application adopts a woven structure member with a support strength smaller than that of the outer frame main body, and compared with the valve frame body, the flexibility of the adaptive zone is better, and when contacting the patient's native tissue, the adaptive zone can adaptively fit the patient's native tissue, thereby avoiding forming pressure on the native tissue;

[0036] 3. The valve stent of the present application adopts a radial interference design to make the valve prosthesis and the native valve annulus position form a good fitting effect, effectively avoiding paravalvular leakage;

[0037] 4. The combination structure design of the inner and outer layer frames in the present application avoids the influence on the inner layer frame when the outer layer frame is extruded by the beating heart, maintains the normal opening and closing function of the valve leaflets, and thus achieves better treatment effect. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 Structure diagram of the outer frame body in Example 1;

[0039] Figure 2 Structure diagram of the valve stent in Example 1;

[0040] Figure 3 Top view of the valve stent in Example 1;

[0041] Figure 4 Bottom view of the secondary support part of the outer frame body in Example 1;

[0042] Figure 5 Structure diagram of the secondary support part of the outer frame body in Example 1;

[0043] Figure 6 Structure diagram of the secondary support part of the outer frame body in Example 1;

[0044] Figure 7 Structure diagram of the inner frame body in Example 1;

[0045] Figure 8 Top view of the valve prosthesis in Example 2;

[0046] Figure 9 Structure diagram of the valve prosthesis in Example 2;

[0047] Figure 10 Structure diagram of the hook claw and the native tissue in Example 2;

[0048] Figure 11 Structure diagram of the valve prosthesis on the tricuspid annulus in Example 2;

[0049] Figure 12 Structure diagram of the valve prosthesis on the mitral annulus in Example 2;

[0050] Figure 13 Structure diagram of the mesh stent in the prior art.

[0051] REFERENCE NUMERALS:

[0052] 1. outer layer frame body; 11. outer frame main body; 111. secondary support portion; 112. main support portion; 1121. wave crest; 113. connecting hole; 114. hook claw; 115. self-adaptive area; 12. woven structure piece; 2. inner layer frame body; 21. main body portion; 22. wave structure portion; 221. first wave structure; 2211. wave crest; 222. second wave structure; 3. sutured membrane; 4. leaflet assembly; 5. native leaflet; 6. atrial septum; 7. tricuspid annulus; 8. atrioventricular node; 9. mitral annulus; 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 objectives, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application are described in detail below in conjunction with the drawings. In the following description, a large number of specific details are set forth in order to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the scope of the present application, so the present application is not limited to the specific implementations disclosed below.

[0054] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0055] It should be noted that the structures, proportions, sizes, etc. shown in the drawings of the specification are for the purpose of illustrating the content described in the specification, for the purpose of understanding and reading by those skilled in the art, and do not have technical substantial significance, and any modification of the structure, change of the proportion relationship or adjustment of the size, without affecting the effect and purpose that can be achieved by the present application, shall fall within the scope of the technical content disclosed by the present application.

[0056] It should be clear that the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor belong to 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 the 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 the plural forms, unless the context clearly indicates otherwise.

[0058] It should be noted that the "up", "down", "left", "right" and other directional words described in the embodiments of the present application are described in the angle shown in the drawings, and should not be understood as a limitation on the embodiments of the present application. In addition, it should also be understood in the context that when referring to one element connected to another element "on" or "under", it can be directly connected to another element "on" or "under" or indirectly connected to another element "on" or "under" through an intermediate element.

[0059] The terms "bottom", "top", "lower", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore cannot be understood as a limitation on the present application.

[0060] Unless otherwise explicitly specified and limited, the terms "connected", "connected" should be broadly understood, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected, it can be directly connected, or indirectly connected through an intermediate medium, it can be internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

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

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

[0063] As used herein, the term "abutment" refers to direct physical contact with each other.

[0064] The artificial heart valve stent provided by the present application is composed of different types of artificial valve leaflet assemblies 4 and suture membranes 3 by setting different diameters of the outer layer frame body 1 and the inner layer frame body 2.

[0065] The present application discloses a valve stent, which comprises an inner layer frame body and an outer layer frame body, the outer layer frame body is sleeved outside the inner layer frame body and is fixedly connected with the inner layer frame body.

[0066] Outer shelf

[0067] In the present application, the outer layer frame body is a hollow mesh structure with open 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 open 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 outward from the top of the curved structure to the axis of the outer frame body.

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

[0069] In some embodiments, the adaptive zone is an unframed area of the secondary support part, which is preferably formed by cutting the outer layer frame body.

[0070] Outer frame body

[0071] In the axial direction, the secondary support part in the outer frame body is located below, and the main support part is located above. The main force bearing part of the main support part is the curved structure, which provides the maximum support force for 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 part of the outer frame body is greater than the native valve annulus diameter, and forms a radial interference structure relative to the native valve annulus to facilitate the valve prosthesis with the valve stent to form a good fitting effect with the native valve.

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

[0074] In some embodiments, the angle between the inclined structure of the main support part and the axis of the outer layer frame body 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 layer frame body can be adaptively selected according to the distance and connection method of the main support part and the secondary support part.

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

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

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

[0078] Optionally, there may be one or more connecting holes provided above the peaks of the waveform structures.

[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] Optionally, the outer frame body can also be made of an elastically or plastically deformable material, such as balloon-expandable, or can 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 a nickel-titanium alloy pipe, and the outer diameter of the pipe is 4 - 50 mm, and the diameter size after shaping is selected according to actual needs.

[0083] Adaptive zone and braided structural member

[0084] In the present invention, the circumferential length of the adaptive zone does not exceed one-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, can be 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, 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 structural member can be in a mesh shape, a rhombus shape, a "hui" character shape or a "zhi" character shape.

[0089] In some embodiments, under the condition of meeting the radial support force of the outer frame on the native valve annulus, the material forming the braided structural member can be nickel-titanium alloy, stainless steel or polymer material.

[0090] In some embodiments, the braided structural member is formed by nickel-titanium alloy braided wires.

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

[0092] The connection between the woven structure and the secondary support structure can be welding, riveting or bonding, or the edge of the woven structure can be bound to the edge of the adaptive zone by a flexible wire. In another implementation, the woven structure can be pre-sewn on the sewing membrane of the valve prosthesis, and when the sewing membrane is arranged on the outer frame body, the woven structure covers the area formed by the adaptive zone.

[0093] The inventor of the present application has found that in the prior art, the commonly used structure of the valve stent is a single-layer hollow mesh structure. For example, a replacement device is disclosed in Chinese patent application CN200710007443.3, which is a mesh stent made of a memory metal material, as shown in Figure 13 The mesh stent in this scheme is divided into three parts: a main aortic stent 100 with a large diameter, a valve stent 200 with a small diameter, and a right ventricular outflow tract stent 300 with an appropriate diameter, so that the stent can be positioned in accordance with the characteristics of the heart structure and is not prone to mispositioning. In the mesh structure of this single-layer structure, the stent 300 is used to provide radial support force to firmly embed the mesh stent on the native valve annulus.

[0094] If the stent 300 is considered to avoid the native structure at a specific position in terms of structure, the technical means disclosed in the prior art includes: 1. increasing the mesh of the stent 300 at the area corresponding to the native structure after reaching the predetermined position; 2. forming a vacancy in the stent 300 at the area corresponding to the native structure after reaching the predetermined position to avoid the native structure.

[0095] With the above two schemes, when the stent 300 provides radial support force, the radial stress of the increased mesh area will be weakened, or the radial stress of the vacancy area will be missing. Since the stent 300 is installed in the aortic valve, the blood flow at this position has a large scouring force. If the radial support force of the stent 300 is weakened, it will be scoured by blood and fall off, so in the structure of the existing single-layer frame, the skilled person in the art usually does not consider increasing the mesh or opening a vacancy area to avoid the native structure.

[0096] In the structure of some existing valve stents, the valve stent also has a double-layer structure of an inner stent and an outer stent. The inner stent is mainly used to bear the artificial valve leaflets and has strong rigidity and small diameter, so as to reduce the area of the artificial valve leaflets and the height required for the opening and closing movement of the valve leaflets; the outer stent has relatively weak rigidity and a large diameter, and is used to prevent paravalvular leakage. The anchoring structure is connected with the inner stent, and the anchoring force preventing the movement of the prosthetic valve is mainly borne by the inner stent with strong rigidity, so as to improve the service life of the stent. Since paravalvular leakage needs to be prevented, the structure of the outer stent also refers to the structural characteristics of the single-layer hollow mesh structure, and the mesh holes are as uniform as possible, so that the outer stent has relatively stable and stable radial support force, so as to avoid paravalvular leakage. Therefore, the person skilled in the art generally does not consider increasing the mesh holes of the outer stent or opening a vacancy area to avoid the native structure.

[0097] In the present application, the inventors adopt the structure of the inner stent and the outer stent, and creatively design the outer stent as two parts of 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 area adapted to the native structure area of the human body is opened on the secondary support part, and a knitted structure member with small support strength is fixed in the adaptive area. The support strength of the knitted structure member is smaller than that of the outer stent. Compared with the valve stent, the flexibility of the adaptive area is better, and when contacting the native tissue of the patient, the adaptive area can be adaptively fitted to the native tissue of the patient, thereby avoiding the formation of compression with the native tissue.

[0098] It should be noted that in the embodiments of the present application, if the area of the adaptive area, i.e., the area of the filled knitted structure member, is too large, the overall stability of the stent will be affected due to the small support strength of the knitted structure member itself. If the area of the adaptive area, i.e., the area of the filled knitted structure member, is too small, the effect of avoiding the native tissue will be affected, and the selection standard can refer to the size of the pre-avoided native tissue.

[0099] In the present application, the support strength of the knitted structure member is small, which can be in the form of a more sparse grid, a finer grid frame, a softer material itself, or a combination thereof. The knitted structure member has a small structural strength and is more flexible under radial stress. The knitted structure member is more easily deformed relative to the outer stent body, avoids extrusion of the native tissue, and can also adapt to the shape of the atrioventricular valve to reduce paravalvular leakage.

[0100] In an embodiment, when the valve prosthesis is in a working state, the part of the filled knitted structure member faces the left ventricular outflow tract or the atrioventricular node.

[0101] Inner shelf

[0102] The inner stent is a cylindrical structure with open ends.

[0103] In some embodiments, the inner frame body is cylindrical or approximately cylindrical, or is a cylindrical structure with trumpet-shaped ends, or is a cylindrical structure with a straight cylindrical end and a trumpet-shaped end.

[0104] In some embodiments, the inner frame body comprises a first wave-shaped structure portion, a main body portion, and a second wave-shaped structure portion connected in sequence, and the wave crests of the first and second wave-shaped structure portions are both away from the main body portion.

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

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

[0107] The material forming the inner frame body can be a metal such as Nitinol, titanium alloy, cobalt-chromium alloy, MP35n, 316 stainless steel, L605, Phynox / Elgiloy (Cobalt-Chromium-Nickel Alloy), platinum-chromium, or other biocompatible metals known to those skilled in the art.

[0108] Alternatively, the inner frame body can also be made of a material that can be elastically or plastically deformed, such as a balloon-expandable material, or can be a shape memory alloy that responds to temperature changes to transform between a contracted delivery state and an expanded deployment state.

[0109] In some embodiments, the inner frame body is cut from a Nitinol tube with an outer diameter of 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 body and an outer frame body.

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

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

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

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

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

[0117] Anchoring units, needling and visualization points

[0118] In some embodiments, the outer layer frame body is provided with an anchoring unit, which protrudes towards the 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 layer frame body, and the other end extends to the side away from the valve stent first, and then bends to extend to the side of the valve stent.

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

[0121] In some embodiments, the hook claw structure is a resilient structure.

[0122] Optionally, a plurality of hook claws are arranged in the circumferential direction of the outer layer frame body.

[0123] In some embodiments, the surface of the hook claw and the connection part with the outer layer frame body are further provided with a film layer, which can be arranged in the form of film covering, woven cloth suturing, etc.

[0124] Optionally, the material of the film layer can be selected from PET, PTFE, ePTFE, PU, etc. biocompatible materials that are easy to endothelialize, or biological tissue materials such as pig pericardium and bovine pericardium.

[0125] In some embodiments, the outer layer frame body is provided with a needle prick, which is used for pinning and fixing, and can more stably fix the valve stent or the prosthesis prepared by the stent.

[0126] In some embodiments, one end of the needle prick is connected to the outer surface of the outer layer frame body, and the other end is inclined towards the outer side of the valve stent.

[0127] In an embodiment, a plurality of needle pricks are arranged on the outer layer frame body, and the needle pricks are connected to the outer layer frame body and inclined towards the radial outer side of the stent.

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

[0129] In other embodiments, the periphery of the filling part of the woven structure is provided with a developing point, which facilitates monitoring the orientation of the woven structure during implantation of the stent.

[0130] Valve prosthesis

[0131] In another aspect of the present application, a valve prosthesis is provided, comprising a valve stent, a suture membrane, and valve leaflets, the suture membrane being wrapped around the valve stent to form a sealed structure.

[0132] In some embodiments, the material of the suture membrane can be PET (polyethylene terephthalate), PTFE (polytetrafluoroethylene), ePTFE (expanded polytetrafluoroethylene), PU (polyurethane), or other biocompatible and endothelialization-friendly materials, or biological tissue materials such as porcine pericardium, bovine pericardium.

[0133] Under the condition that the suture membrane can block the blood flowing through the valve prosthesis from flowing out of the outer stent sidewall, the suture membrane can be a mesh shape with a dense mesh of gaps made of PET, PTFE, ePTFE, PU, or other yarns.

[0134] Alternatively, the suture membrane can be connected to the outer sidewall or the inner sidewall of the stent, for example, by being tied with a non-metallic wire.

[0135] In some embodiments, the valve leaflets are fixedly connected to the suture membrane wrapped around the inner stent sidewall.

[0136] Alternatively, the valve leaflets are sutured to the suture membrane wrapped around the inner stent sidewall.

[0137] The valve prosthesis comprises at least two artificial valve leaflets, the number of artificial valve leaflets being the same as or different from the number of native valve leaflets, one end of the valve leaflets being stably connected to the suture membrane at the inner stent sidewall, and the other end of the valve leaflets being 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 passage.

[0138] The material of the valve leaflet assembly includes biological tissue materials or synthetic materials, for example, the biological tissue materials can be any one of bovine pericardium, sheep pericardium, porcine pericardium, or equine pericardium tissue, and the synthetic materials can be polyurethane, polytetrafluoroethylene, or silicone polyester.

[0139] The valve prosthesis has two morphologies: a compressed state and an expanded state, and in the present application, the features are described in the expanded state unless otherwise emphasized.

[0140] Use

[0141] The present application provides the use of the aforementioned valve stent or the aforementioned valve prosthesis for the preparation of a medical device.

[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 Figures 1-3 As shown, the outer frame 1 is a hollow mesh structure with openings at both ends, including an outer frame body 11 and woven structural members 12. The outer frame body 11 includes an integrally connected secondary support part 111 and a main support part 112. The outer frame body 11 is cut from metal tubing.

[0147] like Figure 1 As shown, the secondary support 111 has a grid structure and is cylindrical or approximately cylindrical. The main support 112 is formed by the top of the outer frame body 11 tapering inward along a straight trajectory. It has a wave-like structure, and a connection hole 113 is provided above the peak 1121 of the wave structure. The traction device for the valve prosthesis is connected through the connection hole 113, or other parts of the prosthesis are connected through the fixation member.

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

[0149] The outer frame 1 is provided with hooks 114. Multiple hooks 114 are evenly arranged in the circumference of the outer frame 1.

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

[0151] The shape of the adaptive region can be rectangular or approximately rectangular, such as... Figure 5 As shown, the adaptive region 115 is rectangular. The axial length a1 of the adaptive region 115 does not exceed the axial length a2 of the secondary support 111. The ratio of the circumferential length b1 of the adaptive region 115 to the perimeter b2 of the secondary support 111 is 1:6-1:2. If the adaptive region is too large, it will affect the stability of the outer frame; if it is too small, it will affect the effect of avoiding the original structure.

[0152] Specifically, the ratio of the axial length a1 of the adaptive region to the axial length a2 of the secondary support can be 1:6 to 1:1; the ratio of the circumferential length b1 of the adaptive region 115 to the circumference b2 of the secondary support can be 1:6 to 1:3.

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

[0154] As Figure 2 or Figure 6 shown, a braided structural member 12 is fixed to the adaptive area 115. The braided structural member 12 is formed by bending nickel-titanium alloy braided wires. The shape of the braided structural member 12 can be a "hui" character shape or a "zhi" character shape. The structural strength of the braided structural member 12 is less than that of the outer frame body 1. When the braided structural member 12 faces the human native tissue or the blood flow path, it adaptively avoids the blood channel and prevents strong obstruction to blood flow.

[0155] The braided structural member 12 is fixedly connected to the outer frame main body 11. The fixed connection method can be by connecting through a fixing member, such as by connecting through a flexible binding band, or it can be that the braided wire is wound around the edge part of the outer frame main body 11 close to the adaptive area 15.

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

[0157] Specifically, the edge parts of the first corrugated structure 221 and the second corrugated structure 222 of the inner frame body can expand outward into a flared structure. The wave crest of the first corrugated structure 221 forms an abutment with the wave crest 1121 of the main support part 112 of the outer frame main body 11. With such a structure, more connection points can be generated between the outer frame body 1 and the inner frame body 2, so the connection between the two will be more stable. Optionally, a binding connection can also be carried out at the abutment to further stabilize the connection between the outer frame body 1 and the inner frame body 2.

[0158] There are multiple hollow parts on the main body part 21 of the inner frame body 2, which can be circular, grid-shaped, diamond-shaped or other patterns.

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

[0160] The distance and structure setting of the inner frame body and the outer frame body are also important because the placement position of the valve stent or the manufactured prosthesis at the valve annulus, the shape of the inner layer stent and the outer layer stent, and the connection relationship therebetween have a great influence on the performance of the valve stent. In the embodiment of the present application, the diameter of the main body part 21 is not less than one half of the diameter of the secondary support part 111 of the outer frame body 2, and the ratio of the diameter of the main body part 21 of the inner frame body 2 to the diameter of the secondary support part 111 of the outer frame body 11 is preferably 1:2-3:5. If the distance between the outer frame body 1 and the inner frame body 2 is too small, the radial support of the prosthesis is unstable, deflection occurs after implantation, the native valve annulus extrudes the inner frame body, and the normal operation of the valve leaflet is affected.

[0161] The forming mode of the inner frame body and the outer frame body includes but is not limited to laser cutting, shearing and wire cutting. Compared with a single-layer valve stent, the double-layer stent has better stability, the inner frame body is not affected when the outer frame body is extruded by the beating heart, the normal opening and closing function of the valve leaflet is maintained, and better treatment effect is achieved.

[0162] Embodiment 2

[0163] The present embodiment provides a valve prosthesis which can be used to replace various types of human body valves such as aortic valve, mitral valve, tricuspid valve and the like.

[0164] The difference between the present embodiment and embodiment 1 is that, as shown in Figure 8 or Figure 9 The valve prosthesis further comprises a suture membrane 3 and a valve leaflet assembly 4. The suture membrane 3 entirely wraps the valve stent to form a sealed structure. The valve leaflet assembly 4 comprises at least two valve leaflets, and the valve leaflet assembly 4 is sutured to the suture membrane wrapped on the side wall of the inner frame body 2.

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

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

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

[0168] When the valve prosthesis is implanted into the human body through the delivery system, the prosthesis is constricted in the delivery system, and at the implantation position in the human body, the prosthesis is automatically expanded or expanded by balloon pressurization after being released, and is limited on the annulus, and when the implantation position is the tricuspid valve, one side of the prosthesis can be selected to abut against the atrial septum 6, thereby completing the implantation of the valve prosthesis. At the same time, the original leaflet 5 is hooked by the hook 114 Figure 10 ), forming an anchoring effect on it.

[0169] The maximum support diameter of the main support part 112 is slightly larger than the human body annulus (which can be 1.1-1.2 times the diameter of the annulus), and when implanted in the annulus of the human body, the outer frame body 1 is clamped at the annulus of the human body, so that the frame body is in interference fit with the annulus of the human body to realize the limitation of the valve prosthesis at the annulus, and to avoid paravalvular leakage.

[0170] There is an atrioventricular node around the original annulus, located under the right endocardium of the atrial septum, in front of the coronary sinus orifice, the tricuspid septal valve attachment edge and the Todaro tendon (Tendon of Todaro), forming the Koch triangle (Triangle of Koch). The vertex of the front part of the triangle, i.e. the junction of the anterior leaflet and the septal valve, is the atrioventricular node. The atrioventricular node is an important part of the cardiac conduction system, and the Todaro tendon has the functions of supporting and pulling the inferior vena cava valve and the coronary sinus valve, and also has the functions of supporting and fixing the myocardium under the atrial septum. Therefore, in the design of the tricuspid valve prosthesis at the original position, the Koch triangle area should be avoided as much as possible.

[0171] The existing tricuspid valve design basically uses clamping or grabbing the leaflet to anchor, and these two anchoring methods will pull the chordae tendineae and cause damage to the original leaflet. There is also an anchoring method using the atrial septum, but this anchoring method is not reliable and needs to additionally use the form of clamping the leaflet, otherwise it is easy to fall off and has safety hazards. In addition, there is a risk of conduction block. By anchoring through the stent body, the stent will compress the conduction tissue, which will have the risk of conduction block.

[0172] As shown in Figure 11 , in one embodiment, the valve prosthesis of the present application is a tricuspid valve prosthesis. When the valve prosthesis is implanted, it is limited on the tricuspid annulus 7, and the woven structure 12 is directed towards the atrioventricular node 8 position, which can adapt to the atrioventricular structure, avoid the compression damage of the structure with high strength outer frame body 11, and cause the occurrence of atrioventricular conduction abnormalities.

[0173] The mitral valve, also known as the left atrioventricular valve, is attached to the left fibrous atrioventricular ring and is formed by folds in the endocardium. There are two valves: the anterior mitral valve, located anteromedially, marks the boundary between the inflow and outflow tracts of the left ventricle; the posterior mitral valve, located posterolaterally, is smaller. Both valves are triangular in shape, with their apexes pointing towards the left ventricular cavity. The bases of the two valves often fuse together, and sometimes a small accessory valve appears between them. Numerous chordae tendineae connect the valve apex, margins, and ventricular surface to the papillary muscles. During ventricular contraction, the mitral valve tightly closes the atrioventricular orifice, preventing backflow of blood into the left atrium.

[0174] When the native mitral valve becomes diseased, an artificial valve can be implanted into the body through interventional procedures to replace the function of the native mitral valve. The artificial valve is delivered to the implantation site via a delivery system and secured to the corresponding valve annulus.

[0175] The left ventricular outflow tract is located on one side of the mitral valve annulus. When a mitral valve prosthesis is implanted, the valve assembly is open during diastole, and blood flows through the valve prosthesis into the left ventricle. During systole, the valve assembly is closed, and blood flows into the left ventricular outflow tract under the pressure of the heart.

[0176] Current mitral valve prostheses employ a radial interference design. After implantation, the stent's inflow tract is tightly fitted to the atrioventricular orifice at the junction of the atrium and ventricle, covering the original mitral valve annulus. Therefore, there is a risk of left ventricular outflow tract obstruction after mitral valve prosthesis implantation.

[0177] like Figure 12 As shown, in one embodiment, the valve prosthesis of the present invention is a mitral valve prosthesis. When implanted, the prosthesis is positioned on the mitral valve annulus 9. When the prosthesis is in operation, during diastole, the leaflet assembly 4 is open, allowing blood to flow through the prosthesis into the left ventricle; during systole, the leaflet assembly 4 is closed, allowing blood to flow into the left ventricular outflow tract 10 under the pressure of the heart. The braided structure 12 faces towards the side closest to the left ventricular outflow tract 10. Therefore, the braided structure 12 deforms under the compression of the native annulus, reducing its impact on the native outflow tract and facilitating blood flow out of the left ventricular outflow tract 10. This design maintains good radial support while minimizing damage to the patient's native tissues and preserving the overall stability of the valve prosthesis.

[0178] Obviously, many modifications and variations can be made based on the content of this specification. These embodiments have been selected and specifically described in this specification to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to make good use of the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A valve stent, characterized in that, Includes inner frame and outer frame; The outer frame is a hollow mesh structure with openings at both ends, including an outer frame body and woven structural members. The outer frame body includes a main support and a secondary support connected sequentially in the axial direction. The secondary support has an adaptive zone. The woven structural members are fixed to the secondary support and cover the adaptive zone. The support strength of the woven structural members 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 on the inner frame and fixedly connected to the inner frame. The circumferential length of the adaptive region does not exceed one-half of the circumference of the secondary support portion; The axial length of the adaptive zone does not exceed the axial length of the secondary support portion; The adaptive zone is the frameless area of ​​the secondary support.

2. The valve stent according to claim 1, characterized in that, The main support includes a curved structure connected to the secondary support and an inclined structure that converges from the top of the curved structure toward the axis of the outer frame body. The secondary support is a cylindrical structure with openings at both ends, and the adaptive region is located on the circumferential sidewall of the secondary support.

3. The valve stent according to claim 2, characterized in that, The ratio of the circumferential length of the adaptive region to the perimeter of the secondary support is 1:6 to 1:

3.

4. The valve stent according to claim 2, characterized in that, The ratio of the axial length of the adaptive zone to the axial length of the secondary support is 1:6-1:

1.

5. The valve stent according to claim 1, characterized in that, The woven structural component is fixedly connected to the secondary support portion.

6. The valve stent according to claim 5, characterized in that, The fixed connection method is to connect through fasteners or to wrap the braided wires forming the braided structure around the edge of the adaptive area of ​​the outer frame body.

7. The valve stent according to claim 1, characterized in that, The woven structural component is formed from nickel-titanium alloy braided wires.

8. The valve stent according to claim 1, characterized in that, The inner frame includes a first waveform structure portion, a main body portion, and a second waveform structure portion connected to each other, wherein the peaks of the first waveform structure portion and the second waveform structure portion are both far away from the main body portion.

9. The valve stent according to claim 8, characterized in that, When the inclined structure of the outer frame body is a waveform structure, the peak of the first or second waveform structure of the inner frame body abuts against the peak of the inclined structure.

10. The valve stent according to claim 8, characterized in that, The diameter of the main body of the inner frame is not less than half the diameter of the secondary support part of the outer frame.

11. The valve stent according to claim 10, characterized in that, The ratio of the diameter of the inner frame main body to the diameter of the outer frame secondary support part is 1:2 - 3:

5.

12. The valve stent according to claim 1, characterized in that, The maximum support diameter of the main support part of the outer frame is greater than the diameter of the petal ring.

13. The valve stent according to claim 12, characterized in that, The maximum support diameter of the main support part of the outer frame is 1.1-1.3 times the diameter of the petal ring.

14. The valve stent according to claim 12, characterized in that, The maximum support diameter of the main support part of the external frame is 1.1-1.2 times the diameter of the petal ring.

15. The valve stent according to any one of claims 1-14, characterized in that, The outer frame is provided with anchoring units, which protrude in the direction away from the valve stent.

16. The valve stent according to claim 15, characterized in that, 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 in a direction away from the valve stent, and then bends and extends towards the side of the valve stent.

17. The valve stent according to claim 15, characterized in that, The anchoring unit is a hook-claw structure.

18. The valve stent according to claim 17, characterized in that, The hook structure is an elastic structure.

19. The valve stent according to claim 15, characterized in that, The outer frame is equipped with needles.

20. The valve stent according to claim 19, characterized in that, One end of the needle is connected to the outer surface of the outer frame, and the other end is tilted towards the outside of the valve stent.

21. A valve prosthesis, characterized in that, The valve includes the valve stent, suture membrane, and leaflet as described in any one of claims 1-20, wherein the suture membrane surrounds the valve stent to form a sealing structure.

22. The valve prosthesis according to claim 21, characterized in that, The leaflets are fixedly connected to the suture membrane on the side wall of the inner frame.

23. The valve prosthesis according to claim 21, characterized in that, When the valve prosthesis is in working condition, the adaptive zone on the valve stent faces the left ventricular outflow tract or atrioventricular node.

24. Use of the valve stent according to any one of claims 1-20 or the valve prosthesis according to any one of claims 21-23 in the manufacture of a medical device.

25. The use according to claim 24, characterized in that, The medical device in question is a heart valve prosthesis.

26. The use according to claim 24, characterized in that, The medical device is a mitral valve prosthesis or a tricuspid valve prosthesis.

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