Artificial valve stent and artificial valve prosthesis

Abstract

The invention relates to an artificial valve stent and an artificial valve prosthesis, the artificial valve stent is used for a valve-in-valve operation, and the artificial valve stent comprises a stent main body used for being accommodated in an original bioprosthetic valve in a body; all the positioning supporting arms are arranged at one end of the artificial valve stent and distributed in the circumferential direction of the stent body, one end of each positioning supporting arm is connected with the stent body, and the other end of each positioning supporting arm extends towards the other end of the artificial valve stent from the lateral outer portion of the stent body. And the clamp is used for clamping the original bioprosthetic valve. During a valve-in-valve operation, the artificial valve support can be stably and reliably anchored with an original bioprosthetic valve through a unique anchoring structure, and the artificial valve support is suitable for valve-in-valve replacement of a double-layer bioprosthetic valve.

Description

Technical Field

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

[0002] The heart contains four chambers, namely the right atrium (RA), right ventricle (RV), left atrium (LA) and left ventricle (LV). The pumping action of the left and right sides of the heart generally occurs synchronously throughout the cardiac cycle. The valves that separate the atria from the ventricles are called the atrioventricular valves, which act as one-way valves to ensure the normal flow of blood in the heart chambers. The atrioventricular valve between the left atrium and the left ventricle is the mitral valve, and the atrioventricular valve between the right atrium and the right ventricle is the tricuspid valve. The pulmonary valve directs blood flow to the pulmonary artery and from there to the lungs; blood returns to the left atrium through the pulmonary veins. The aortic valve directs blood flow through the aorta and from there to the periphery. There is usually no direct connection between the ventricles or between the atria. At the beginning of ventricular filling (diastole), the aortic valve and the pulmonary valve close to prevent backflow from the arteries into the ventricles. Shortly thereafter, the atrioventricular valve opens to allow unimpeded flow from the atria into the corresponding ventricle.

[0003] The tricuspid and mitral valves normally close shortly after the onset of ventricular systole (i.e., emptying of the ventricles), forming a seal that prevents backflow from the ventricles into the corresponding atria. The failure of the valve leaflets to seal during ventricular systole is called malcoaptation and can allow blood to flow backwards (regurgitation) through the valves. Heart valve insufficiency can have serious consequences for patients, often leading to heart failure, decreased blood flow, decreased blood pressure, and / or decreased oxygen flow to the body's tissues. Aortic valve insufficiency can also cause blood to flow back from the left atrium into the pulmonary veins, causing congestion. Severe valvular insufficiency, if not treated, can lead to permanent disability or death.

[0004] In recent years, biological valves have developed rapidly, but the durability of the valve leaflets is an issue that cannot be ignored. The "valve-in-valve" surgery requires valve replacement in the biological valve frame that has already been placed in the patient, that is, "putting a new valve in a bad valve"; in addition, if the first implantation is not ideal, "valve-in-valve" is also a remedy. In the valve-in-valve surgery, how to achieve the anchoring of the valve frame implanted for the second time with the valve frame implanted for the first time is very important, especially for the biological valve with double-layer stents that have appeared. Due to the complex structure of the double-layer stent, the irregular shape of the inner stent, and the large number of skirt structures, most of the valves in the existing technology are difficult to meet the surgical requirements of the "valve-in-valve" with double-layer stents.

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

[0006] The purpose of the present invention is to provide an artificial valve stent and an artificial valve prosthesis, which are suitable for valve-in-valve surgery and aim to achieve stable and reliable anchoring with the original biological valve in the body through a unique anchoring structure. Even if the original biological valve adopts a double-layer stent, it can meet the surgical requirements of valve-in-valve.

[0007] To achieve the above object, the present invention provides an artificial valve stent for valve-in-valve surgery, comprising:

[0008] A stent body, the stent body being used to be accommodated in an existing biological valve in the body; and

[0009] At least three positioning support arms, all of which are arranged at one end of the artificial valve stent and distributed along the circumference of the stent body, one end of each of the positioning support arms is connected to the stent body, and the other end of each of the positioning support arms is bent at the lateral outside of the stent body to extend toward the other end of the artificial valve stent and is used to clamp the original biological valve.

[0010] Optionally, one end of the artificial valve stent is the inflow end, and the other end of the artificial valve stent is the outflow end, all the positioning support arms are arranged at the inflow end, and the other end of each positioning support arm extends toward the outflow end of the artificial valve stent on the lateral outside of the stent body, and is used to clamp on the inflow end of the original biological valve.

[0011] Optionally, one end of the artificial valve stent is the outflow end, and the other end of the artificial valve stent is the inflow end, all the positioning support arms are arranged at the outflow end, and the other end of each positioning support arm extends toward the inflow end of the artificial valve stent on the lateral outside of the stent body and is used to clamp on the outflow end of the original biological valve.

[0012] Optionally, the outer diameter of the stent body after expansion is greater than the inner diameter of the original biological valve after expansion in vivo.

[0013] Optionally, the number of the positioning support arms is three, and the three positioning support arms are evenly distributed along the circumference of the bracket body.

[0014] Optionally, it further comprises a plurality of barbs, wherein the barbs protrude from the lateral outer wall of the bracket body, and the barbs and the positioning support arm are arranged facing each other.

[0015] Optionally, the positioning support arm can be folded and unfolded, and the positioning support arm is connected to the bracket body in an integral or separate manner.

[0016] Optionally, one end of the positioning support arm is smoothly connected to the bracket body, and / or the other end of the positioning support arm is of a smooth structure.

[0017] Optionally, the original biological valve is a double-layer stent or a single-layer stent. When the original biological valve is a double-layer stent, the stent body is used to be accommodated in an inner stent of the double-layer stent, and the other end of the positioning support arm is used to clamp the inner stent.

[0018] Based on the same inventive concept, the present invention also provides an artificial valve prosthesis, which is provided with any one of the artificial valve stents described.

[0019] The above-mentioned artificial valve stent includes: a stent body, which is used to be accommodated in the original biological valve in the body; and at least three positioning support arms, all of which are arranged at one end of the artificial valve stent and distributed along the circumference of the stent body, one end of each of the positioning support arms is connected to the stent body, and the other end of each of the positioning support arms extends from the lateral outside of the stent body toward the other end of the artificial valve stent, and is used to clamp the original biological valve. After such configuration, the present invention can realize valve-in-valve replacement for the original biological valve implanted in the body. During the replacement, it is only necessary to place the stent body of the artificial valve stent in the original biological valve in the body, and clamp the original biological valve through multiple positioning support arms to realize positioning and anchoring. This structure is simple, positioning is accurate, the surgical operation is not complicated and the reliability is high, and it has a small size and does not affect the positioning performance of the original biological valve in the body.

[0020] Since the artificial valve prosthesis provided in the present application and the artificial valve stent provided in the present application belong to the same inventive concept, the artificial valve prosthesis provided in the present application has all the advantages of the artificial valve stent provided in the present application. Therefore, the beneficial effects of the artificial valve prosthesis provided in the present application will not be described one by one here. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Those skilled in the art will appreciate that the accompanying drawings are provided for a better understanding of the present invention and do not constitute any limitation on the scope of the present invention.

[0022] Figure 1 1 is a schematic diagram of the overall structure of an artificial valve stent provided according to an embodiment of the present invention, wherein a positioning support arm is arranged at the inflow end of the artificial valve stent;

[0023] Figure 2 yes Figure 1 A schematic diagram of the local structure of the artificial valve stent;

[0024] Figure 3 yes Figure 1 A top view of the artificial valve stent when viewed from the inflow end to the outflow end;

[0025] Figure 4 It is a schematic diagram of an application scenario of delivering an artificial valve stent for valve-in-valve replacement of a mitral valve through a delivery system provided according to an embodiment of the present invention, wherein a positioning support arm is arranged at the inflow end of the artificial valve stent;

[0026] Figure 5 It is a schematic diagram of a scene of placing an artificial valve stent in an existing biological valve in the body according to an embodiment of the present invention, wherein the positioning support arm is positioned on the inflow end of the existing biological valve;

[0027] Figure 6 It is a schematic diagram of an application scenario of delivering an artificial valve stent for valve-in-valve replacement of a mitral valve through a delivery system according to another embodiment of the present invention, wherein a positioning support arm is arranged at the outflow end of the artificial valve stent;

[0028] Figure 7 It is a schematic diagram of placing an artificial valve stent in an existing biological valve in the body by clamping the positioning support arm on the outflow end of the original biological valve according to another embodiment of the present invention;

[0029] Figure 8 1 is a partial structural schematic diagram of a positioning support arm provided according to an embodiment of the present invention being clamped at a position corresponding to a support rod on a skirt, wherein a dotted line represents the support rod on the inner side of the skirt;

[0030] Fig. 9 is a partial structural schematic diagram of a positioning support arm provided in accordance with another embodiment of the present invention being clamped at a position corresponding to a grid hole on a skirt, wherein the dotted line represents a support rod on the inner side of the skirt;

[0031] Fig.10 It is a schematic diagram of a scenario in which a balloon-expandable stent is used for valve-in-valve replacement in a comparative embodiment.

[0032] The markings in the figure are as follows:

[0033] 1-balloon catheter; 2-balloon expandable stent; 100-artificial valve stent; 101-inflow end; 103-outflow end; 110-stent body; 120-positioning support arm; 121-clamping end; 130-barb; 140-connecting part; 200-delivery system; 210-sheath; 220-conical head; 230-catheter; 300-original biological valve; 301-stent rod; 302-grid hole; 310-inner stent; 320-outer stent; 330-skirt; 340-tie. DETAILED DESCRIPTION

[0034] In order to make the purpose, advantages and features of the present invention more clear, the present invention is further described in detail below with reference to the accompanying drawings. It should be noted that the accompanying drawings are all in a very simplified form and are not in precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0035] In this document, "top" and "bottom" are viewed from the direction of the heart's blood flow through the artificial valve prosthesis. Although "top" and "bottom" are not restrictive, "top" generally refers to the end close to the blood flow flowing into the artificial valve prosthesis, and "bottom" generally refers to the end close to the blood flow flowing out of the artificial valve prosthesis. As used in this specification, the singular forms "one", "an" and "the" include plural objects unless the content clearly indicates otherwise. As used in this specification, the term "or" is generally used in the sense of including "and / or" unless the content clearly indicates otherwise. In addition, the term "radial" or "transverse" refers to the direction perpendicular to the axis of the artificial valve prosthesis or artificial valve stent; "axial" refers to the direction parallel to the axis of the artificial valve prosthesis or artificial valve stent; "circumferential" refers to the direction around the axis of the artificial valve prosthesis or artificial valve stent.

[0036] The core of the present invention is to provide an artificial valve stent and an artificial valve prosthesis, which are suitable for transcatheter valve-in-valve surgery and for treating the aortic valve, mitral valve, tricuspid valve and pulmonary valve, and are particularly suitable for treating the mitral valve and tricuspid valve.

[0037] The artificial valve stent provided by the present invention can achieve stable and reliable anchoring with the original biological valve in the body through a unique anchoring structure, and for biological valves using double-layer stents, valve-in-valve replacement can also be achieved, reducing the difficulty of replacement.

[0038] Specifically, the artificial valve stent provided by the present invention includes a stent body and at least three positioning support arms, all of which are arranged at one end of the artificial valve stent and distributed along the circumference of the stent body, one end of each positioning support arm is connected to the stent body, and the other end of each positioning support arm extends from the lateral outside of the stent body toward the other end of the artificial valve stent. When valve-in-valve replacement is required, the stent body only needs to be placed in the original biological valve in the body, and the original biological valve is clamped by the other end of the positioning support arm, so as to achieve stable and reliable anchoring.

[0039] The positioning support arm can be arranged at any end of the artificial valve stent, for example, at the inflow end or outflow end of the artificial valve stent. It is understandable that when the positioning support arm is arranged at the inflow end of the artificial valve stent, the other end of the positioning support arm extends toward the outflow end of the artificial valve stent, so as to be positioned on the inflow end of the original biological valve to achieve stable and reliable anchoring; conversely, when the positioning support arm is arranged at the outflow end of the artificial valve stent, the other end of the positioning support arm extends toward the inflow end of the artificial valve stent, so as to be positioned on the outflow end of the original biological valve to achieve stable and reliable anchoring.

[0040] The following description is given with reference to the accompanying drawings.

[0041] like Figures 1 to 9 As shown, the present invention relates to an artificial valve stent 100, which has an inflow end 101 and an outflow end 103 along its own axial direction. According to the normal flow direction of blood, the outflow end 103 is located downstream of the inflow end 101, and the direction from the inflow end 101 to the outflow end 103 can be defined as the axial direction of the artificial valve stent 100. For example, from Figure 1 In the illustrated orientation, the inflow end 101 is the top end, and the outflow end 103 is the bottom end. In more detail, the artificial valve stent 100 includes a stent body 110 and at least three positioning support arms 120 .

[0042] like Figures 1 to 5As shown, in one embodiment of the present invention, all positioning support arms 120 are arranged at the inflow end 101 of the artificial valve stent 100 and distributed along the circumference of the stent body 110. Preferably, all positioning support arms 120 are evenly distributed along the circumference of the stent body 110, the force is evenly applied, and the stability is better. The number of positioning support arms 120 is three or more. Preferably, three positioning support arms 120 are used, the structure is not complicated and the size will not increase too much. Further, one end (i.e., the fixed end) of each positioning support arm 120 is connected to the stent body 110, and the other end 121 (i.e., the clamping end) of each positioning support arm 120 extends toward the outflow end 103 of the artificial valve stent 100 on the lateral outside of the stent body 110. The length of the other end 121 of the positioning support arm 120 extending toward the outflow end 103 is not specifically limited. Generally speaking, the extension length of the other end 121 of the positioning support arm 120 will not be too long to avoid interference from the skirt 330 on the original biological valve 500.

[0043] The positioning support arm 120 is similar to a hook, but also provides a clamping function. In actual use, the other end 121 of the positioning support arm 120 can not only be clamped on the original biological valve 300 in the body, but also can use its own elasticity to clamp the original biological valve 300. The original biological valve 300 is an old biological valve that has been implanted in the native valve of the body. Here, those skilled in the art can refer to the prior art to understand the structure of the original biological valve 300, and this application will not elaborate on this.

[0044] See also Figure 4 and Figure 5 When the positioning support arm 120 is arranged at the inflow end 101 of the artificial valve stent 100, when valve-in-valve replacement is required, the stent body 110 is accommodated in the original biological valve 300 in the body. At this time, the other end 121 of the positioning support arm 120 clamps the original biological valve 300. In this embodiment, the other end 121 of the positioning support arm 120 is clamped at the inflow end of the original biological valve 300 to achieve anchoring and clamping. For more details, please refer to Figure 8 and Fig. 9 .

[0045] Reference Figure 6 and Figure 7 As shown, in another embodiment of the present invention, all positioning support arms 120 are arranged at the outflow end 103 of the artificial valve stent 100 and are distributed along the circumference of the stent body 110. At this time, the other end 121 of each positioning support arm 120 extends toward the inflow end 101 of the artificial valve stent 100 from the lateral outside of the stent body 110.

[0046] In this way, the present invention can achieve valve-in-valve replacement for the original biological valve 300 that has been implanted in the body. During the replacement, it is only necessary to place the stent body 110 of the artificial valve stent 100 in the original biological valve 300, and realize anchoring and clamping while positioning through multiple positioning support arms 120. This structure is simple, accurate in positioning, uncomplicated in surgical operation and highly reliable, and has a small size and does not affect the positioning performance of the original biological valve 300.

[0047] Furthermore, the outer diameter of the stent body 110 after expansion is larger than the inner diameter of the original biological valve 300 after expansion in vivo, so that the stent body 110 can also use its own radial expansion force for support, further reducing the risk of displacement of the stent body 110 relative to the original biological valve 300. Here, the inner diameter of the original biological valve 300 after expansion in vivo is the inner diameter squeezed by the native tissue.

[0048] It should also be noted that the artificial valve stent 100 of the present invention can achieve valve-in-valve replacement for the original biological valve 300 of the double-layer stent or the single-layer stent.

[0049] Figure 4 and Figure 5 The illustrated application scenario is the valve-in-valve replacement of the original biological valve 300 of the double-layer stent. Figure 5 As shown, when the original biological valve 300 with a double-layer stent is used, the stent body 110 is placed in the inner stent 310 of the original biological valve 300, and the other end 121 of the positioning support arm 120 clamps the inner stent 310. Preferably, the outer diameter of the stent body 110 after expansion is larger than the inner diameter of the inner stent 310 after expansion in vivo, so that the stent body 110 provides support force in its own radial direction. The inner diameter of the original biological valve 300 after expansion in vivo is the inner diameter of the inner stent 310 after expansion in vivo.

[0050] Further, on the basis of the radial anchoring force provided by the positioning support arm 120 and the stent body 110, if the barbs 130 are combined, the stability and reliability of the anchoring can be further increased. In this way, the stent body 110 is preferably provided with a plurality of barbs 130, the barbs 130 protrude from the lateral outer wall of the stent body 110, and the barbs 130 are arranged opposite to the positioning support arm 120. Arranged opposite to each other means that if the other end 121 of the positioning support arm 120 faces the outflow end 103, the barbs 130 face the inflow end 101, and if the other end 121 of the positioning support arm 120 faces the inflow end 101, the barbs 130 face the outflow end 103. The barbs 130 are used to anchor with the artificial leaflets on the original biological valve 300 in the body, and can play the role of barb anchoring. In this way, the barbs 130 and the positioning support arm 120 are in opposite directions, and the two are arranged opposite to each other. The barbs 130 can be straight or curved or in other shapes, and are not specifically limited. The barbs 130 are not limited to being arranged on the grid nodes of the support body 110, and the barbs 130 can also be arranged on the mesh rods between the grid nodes. No less than 3 barbs 130 are arranged in the circumferential direction of the support body 110, and the overall direction of the barbs 130 is toward the inflow end 101 or the outflow end 103, so that it is not easy to slip off. The barbs 130 and the positioning support arm 120 cannot be too long. When the barbs 130 are too long, it is not easy to penetrate. When the positioning support arm 120 is too long, it is easy to be affected by the skirt 330. Optionally, the length of the positioning support arm 120 is less than 20 mm.

[0051] The positioning support arm 120 can be folded and unfolded. When folded, it is restrained by the conveying system 200, and unfolds automatically after being separated from the conveying system 200. The positioning support arm 120 can be made of nickel-titanium alloy or other conventional biocompatible materials with shape memory properties.

[0052] The shape of the positioning support arm 120 includes but is not limited to a V-shape or a U-shape. The positioning support arm 120 has a simple structure, is easy to process, and is easily anchored on the original biological valve 300, which can provide a strong anchor for the stent body 100 to avoid axial movement.

[0053] The positioning support arm 120 can be integrally formed and connected with the support body 110, or can be separately formed and connected with the support body 110 by welding, riveting, bonding or other connection methods. In this embodiment, the positioning support arm 120 is cut and formed integrally with the support body 110, such as first laser engraving the pipe into mesh holes and mesh rods, and then bending some crossed mesh rods at the position corresponding to the inflow end 101 or the outflow end 103 to form the positioning support arm 120. In this way, the positioning support arm 120 is equivalent to a clamping arm composed of rods. However, it should also be recognized that the structure of the positioning support arm 120 is not limited to rods, for example, it can also be a mesh, sheet or other structure, as long as the positioning support arm 120 is connected to the support body 110 and can provide an elastic clamping function.

[0054] The positioning support arm 120 can be connected to the stent body 110 smoothly or non-smoothly. A more appropriate way is that the connection between the positioning support arm 120 and the stent body 110 is a smooth connection, such as a rounded connection, so as to reduce stress concentration at the connection and effectively prevent tissue damage at the connection. Preferably, the other end 121 of the positioning support arm 120 is a smooth structure to avoid sharp design and reduce damage to native tissue, skirt, leaflet and other structures. The smooth structure means that the surface of the other end 121 of the positioning support arm 120 is smooth and the shape is rounded without protruding edges and corners.

[0055] like Figure 2 As shown, a plurality of connection parts 140 are provided on the stent body 110, and the plurality of connection parts 140 are distributed along the circumference of the stent body 110. Preferably, the plurality of connection parts 140 are evenly distributed along the circumference of the stent body 110. The connection part 140 is arranged at the inflow end 101 of the artificial valve stent 100. In one embodiment of the present invention, the connection part 140 and the positioning support arm 120 which is also located at the inflow end 101 are staggered and do not overlap each other. Each connection part 140 is used to be detachably connected to the delivery system 200 to ensure that the relative position of the artificial valve prosthesis and the delivery system 200 remains unchanged when the artificial valve prosthesis is loaded into the delivery system 200, released from the delivery system 200, and delivered in the body. There are usually no less than three connection parts 140, and the more suitable number is three. It should be noted that there are many ways to structure the connection part 140, and at least one of them can be selected to be implemented, which is explained exemplarily below.

[0056] like Figure 2 As shown, in this embodiment, the connection portion 140 is a lug with a hole, which can be used to pass the control wire provided by the delivery system 200, for example, to achieve the connection between the artificial valve stent 100 and the delivery system 200, and the control wire can be pulled out of the lug at any time to achieve release. One or two holes can be set on each lug. The lug can be optionally a T-shaped structure, but it is not limited to this. In other embodiments, the connection portion 140 can be snap-connected or plugged with the delivery system 200.

[0057] In addition, based on the same inventive concept, the present invention also provides an artificial valve prosthesis, which includes the artificial valve stent 100 described in any embodiment, and also includes an artificial valve leaflet (not shown). The artificial valve leaflet is two or three pieces, and the artificial valve leaflet is arranged in the stent body 110. The artificial valve leaflet is made of animal pericardium or other biocompatible polymer materials. The artificial valve leaflet replaces the native valve leaflet in the working state to realize the function of opening and closing the blood channel.

[0058] Furthermore, the artificial valve prosthesis may also include a skirt (not shown). The skirt covers the inner side of the stent body 110 to form an inner skirt, or covers the outer side of the stent body 110 to form an outer skirt, or the inner side of the stent body 110 is covered with an inner skirt, and the outer side is covered with an outer skirt. After the skirt is set, paravalvular leakage can be prevented, and a single channel for blood to flow from the inflow end 101 of the artificial valve stent 100 to the outflow end 103 of the artificial valve stent 100 can be better ensured. The skirt is made of pericardium or other biocompatible polymer materials, such as PET (polyethylene terephthalate), PTFE (polytetrafluoroethylene) or other common materials.

[0059] The stent body 110 is woven or cut, preferably cut, for example, prepared by laser engraving. The stent body 110 is a three-dimensional mesh structure, generally cylindrical. The stent body 110 is mostly composed of a diamond grid, which is responsible for carrying artificial valve leaflets, skirts and other structures. The present application does not limit the processing material of the stent body 110, which can usually be made of nickel-titanium alloy or other biocompatible materials with shape memory properties, and can also be made of elastically or plastically deformable materials, such as balloon-expandable materials. Preferably, the stent body 110 is made of nickel-titanium alloy, which can provide strong radial support force and achieve stable and reliable anchoring.

[0060] The following uses a double-layer biological valve stent as an example, and combines the positioning support arm 120 of the inflow end 101 to further illustrate the use of the artificial valve stent 100 and the artificial valve prosthesis of the present invention.

[0061] Reference Figure 4 and Figure 5 As shown, in an existing structure, the biological valve of the double-layer stent includes an inner stent 310 and an outer stent 320, the inner stent 310 is connected to the outer stent 310, and the inner stent 310 may also include a tether 340 arranged at the bottom, and the tether 340 is configured to be fixed to the heart wall or the apex. In practice, the inner stent 310 is mainly used to carry the valve leaflets, and most of them cannot provide sufficient radial anchoring force. For this reason, the outer stent 320 is used for radial anchoring to ensure the positioning performance of the biological valve and the native tissue. In addition, a skirt 330 is provided between the inner stent 310 and the outer stent 320 to block the gap between the inner stent 310 and the outer stent 320. However, it should also be noted that the structure of the biological valve of the existing double-layer stent is not limited to the case exemplified here. As can be understood by those skilled in the art, as long as the stent body 110 can be inserted into the inner stent 310 and the positioning support arm 120 is clamped at the top of the inner stent 310, other biological valves of the double-layer stent with similar or similar functions can also be applied to the present application.

[0062] According to the applicant's research, the traditional valve-in-valve stent cannot be used for valve-in-valve replacement of a double-layer stent biological valve. On the one hand, it is limited by the skirt 330 between the inner and outer stents, so that the anchoring space of the traditional valve-in-valve stent is small, and it is difficult to achieve stable and reliable anchoring. On the other hand, it is also limited by the length of the valve frame, which is not easy to anchor and position. In addition, the excessive radial force of some valve-in-valve stents will also affect the positioning of the outer stent 320 and the native tissue. Therefore, the present application uses a shorter and smaller positioning support arm 120 to be clamped on the top of the inner stent 310 for anchoring and positioning, which is not easily affected by the length of the valve frame and the skirt 330. In addition, the positioning support arm 120 is small in size and flexible in clamping, and can be adapted to any shape of the inner stent 310 (including special-shaped inner stents). At the same time, the barb 130 penetrates into the skirt 330 or the leaflet of the native valve, locking the movement in both axial directions. At the same time, the barb 130 is short and does not affect the normal function of the leaflet of the valve-in-valve.

[0063] The specific implementation process is as follows Figure 4 and Figure 5 As shown, the mitral valve in valve surgery is taken as an example. The delivery system 200 enters above the mitral valve through the atrial septum, and then the tip position of the delivery system 200 is adjusted to align with the original biological valve frame 300. After alignment, the delivery system 200 is continuously pushed toward the mitral valve until it is inserted into the inner stent 310. Then, the sheath 210 of the delivery system 200 is pushed forward to release the positioning support arm 120 first and then pop out. At this time, the bottom end of the artificial valve stent 100 is still bound by the sheath 210, and the barb 130 has not been released. After determining that the bottom end of the artificial valve stent 100 enters the inner stent 310, the position of the artificial valve stent 100 is adjusted to allow the positioning support arm 120 to clamp the inner stent 310. Subsequently, the entire artificial valve stent 100 is completely released to allow the barb 130 to penetrate into the original biological valve to achieve anchoring, that is, the newly replaced artificial valve prosthesis replaces the old biological valve and starts to work. Finally, the delivery system 200 is withdrawn, and the valve-in-valve replacement is completed.

[0064] It can be understood that the delivery system 200 includes a sheath 210, a conical head 220 and a catheter 230, the distal end of the catheter 230 is connected to the conical head 220, the artificial valve prosthesis is sleeved on the catheter 230, the sheath 210 is slidably sleeved on the catheter 230 along the axial direction of the catheter 230, and a containing space for compressing the artificial valve prosthesis is formed between the sheath 210 and the catheter 230. Before use, the artificial valve prosthesis is stored between the sheath 210 and the catheter 230, so that the artificial valve prosthesis can smoothly pass through the body structure during delivery; when in use, the delivery system 200 is first delivered to a position such as the mitral valve, and then the sheath 210 is removed by operating the handle to release the compression of the sheath 210 on the artificial valve prosthesis, so that the artificial valve prosthesis is released, and after complete release, the delivery system 200 is withdrawn from the body. The conical head 220 can reduce the resistance of the distal end of the catheter in the human body lumen during transportation, making transportation easier, and is made of soft plastic to prevent puncture of human tissue.

[0065] It should be understood that when the positioning support arm 120 is set at the outflow end 103, its delivery and release methods are basically the same as those when it is set at the inflow end 101. The difference is that during the delivery process, all the positioning support arms 120 at the outflow end 103 are released first, so that the positioning support arms 120 are released and popped out first and stuck on the outflow end of the original biological valve 300, so that the top of the artificial valve stent 100 is still bound by the sheath tube 210 and not released. After the positioning support arm 120 is anchored and clamped, the sheath tube 210 is withdrawn to completely release the entire artificial valve stent 100. Finally, the delivery system 200 is withdrawn.

[0066] In practice, since the original biological valve 300 is often provided with a skirt 330, the positioning support arm 120 in any embodiment is directly clamped on the skirt 330 of the original biological valve 300. For example, the positioning support arm 120 is clamped on the skirt 330 at a position corresponding to the stent rod 301 of the original biological valve 500, which is conducive to enhancing anchoring. The positioning support arm 120 can also be clamped on the skirt 330 at a position corresponding to the grid hole 302 between the stent rods 301, which can achieve the same anchoring clamping effect.

[0067] The positioning support arm 120 of the inflow end 101 is used as a schematic illustration. Figure 8 As shown, the positioning support arm 120 is positioned on the skirt 330 corresponding to the support rod 301. In another embodiment, as Fig. 9 As shown, the positioning support arm 120 is positioned on the skirt 330 at a position corresponding to the grid hole 302 .

[0068] It should also be noted that the conventional balloon-expandable stent 2 for valve-in-valve has a great obstacle when entering such existing biological valves. Fig.10As shown. This is because the front delivery part of the balloon catheter 1 (including the balloon and the tip) has a certain length and diameter, which is longer than the implant and smaller than the diameter of the closing part of the original biological valve. Therefore, when the balloon-expandable stent 2 is delivered into the closing part of the original biological valve 500, the front end of the balloon catheter 1 cannot enter the closing part more deeply, and thus cannot release the balloon-expandable stent 2 at the appropriate position to achieve valve-in-valve replacement. The anchoring method provided by the present invention is particularly suitable for heart valves with certain closing stent structures, such as the original biological valve 500 anchored by the apex drawstring.

[0069] It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the content disclosed in this application, and these improvements and supplements should also be regarded as the protection scope of this application. Any technician familiar with this profession can make some changes, modifications and evolutions of the technical content disclosed above without departing from the spirit and scope of this application, which are equivalent embodiments of this application; at the same time, any changes, modifications and evolutions of any equivalent changes made to the above embodiments based on the essential technology of this application are still within the scope of the technical solution of this application.

Claims

1. An artificial valve stent for valve-in-valve surgery, characterized in that: include: A stent body, the stent body being used to be accommodated in an existing biological valve in the body; as well as, At least three positioning support arms, all of which are arranged at one end of the artificial valve stent and distributed along the circumference of the stent body, one end of each of the positioning support arms is connected to the stent body, and the other end of each of the positioning support arms extends from the lateral outside of the stent body toward the other end of the artificial valve stent and is used to clamp the original biological valve.

2. The artificial valve stent according to claim 1, characterized in that: One end of the artificial valve stent is the inflow end, and the other end of the artificial valve stent is the outflow end. All the positioning support arms are arranged at the inflow end. The other end of each positioning support arm extends toward the outflow end of the artificial valve stent at the lateral outside of the stent body and is used to clamp on the inflow end of the original biological valve.

3. The artificial valve stent according to claim 1, characterized in that: One end of the artificial valve stent is the outflow end, and the other end of the artificial valve stent is the inflow end. All the positioning support arms are arranged at the outflow end. The other end of each positioning support arm extends toward the inflow end of the artificial valve stent at the lateral outside of the stent body and is used to clamp on the outflow end of the original biological valve.

4. The artificial valve stent according to any one of claims 1 to 3, characterized in that: The outer diameter of the stent body after expansion is greater than the inner diameter of the original biological valve after expansion in vivo.

5. The artificial valve stent according to any one of claims 1 to 3, characterized in that: The number of the positioning support arms is three, and the three positioning support arms are evenly distributed along the circumference of the bracket body.

6. The artificial valve stent according to any one of claims 1 to 3, characterized in that: The support body is provided with a plurality of barbs, the barbs protrude from the lateral outer wall of the support body, and the barbs and the positioning support arm are arranged facing each other.

7. The artificial valve stent according to any one of claims 1 to 3, characterized in that: The positioning support arm can be folded and unfolded, and the positioning support arm is connected to the bracket body in an integral or separate manner.

8. The artificial valve stent according to any one of claims 1 to 3, characterized in that: One end of the positioning support arm is smoothly connected to the bracket body, and / or the other end of the positioning support arm is of a smooth structure.

9. The artificial valve stent according to any one of claims 1 to 3, characterized in that: The original biological valve is a double-layer stent or a single-layer stent. When the original biological valve is a double-layer stent, the stent body is used to be accommodated in the inner stent of the double-layer stent, and the other end of the positioning support arm is used to clamp the inner stent.

10. An artificial valve prosthesis, characterized in that: An artificial valve stent as described in any one of claims 1 to 9 is provided.

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