Prosthetic valve stent and prosthetic valve endoprosthesis

Abstract

The present application relates to a kind of artificial valve stents and artificial valve prosthesis, artificial valve stent is used in valve-in-valve surgery, it includes: stent body, for accommodating in the original biological valve in body;And at least three positioning support arms, all positioning support arms are arranged in one end of artificial valve stent, and distribute along the circumference of stent body, one end of each positioning support arm is connected with stent body, the other end of each positioning support arm extends to the direction of the other end of artificial valve stent at the lateral exterior of stent body, and is used for clamping original biological valve.Valve-in-valve surgery, the artificial valve stent can be realized stable and reliable anchoring with original biological valve by unique anchoring structure, and it is suitable for the valve-in-valve replacement of double-layer biological 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: the right atrium (RA), right ventricle (RV), left atrium (LA), and left ventricle (LV). Throughout the cardiac cycle, the pumping action of the left and right sides of the heart generally occurs synchronously. The valves separating the atria from the ventricles are called the atrioventricular valves. They act as one-way valves, ensuring the normal flow of blood within the heart chambers. The atrioventricular valve between the left atrium and the left ventricle is the mitral valve, and the atrioventricular valve between the right atrium and the right ventricle is the tricuspid valve. The pulmonary valve directs blood flow to the pulmonary artery, from where it flows to the lungs; blood returns to the left atrium through the pulmonary veins. The aortic valve directs blood flow through the aorta, from where it flows to the pericardium. There are typically no direct connections between the ventricles or between the atria. At the beginning of ventricular filling (diastole), the aortic and pulmonary valves close to prevent backflow from the arteries into the ventricles. Shortly thereafter, the atrioventricular valves open to allow unimpeded flow from the atria into the corresponding ventricles.

[0003] Shortly after the onset of ventricular systole (i.e., when the ventricles empty), the tricuspid and mitral valves normally close, 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 backward through the valves (regurgitation). Heart valve insufficiency can have serious consequences for patients, often leading to heart failure, decreased blood flow, lowered 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 left untreated, can lead to permanent disability or death.

[0004] Bioprosthetic valves have advanced rapidly in recent years, but the durability of their leaflets remains a significant concern. "Valve-in-Valve" surgery involves replacing a valve within an existing bioprosthetic valve, essentially inserting a new valve within a damaged one. Furthermore, "Valve-in-Valve" surgery is a remedial measure if the initial implantation is unsatisfactory. During valve-in-valve surgery, anchoring the second implanted valve to the first is crucial, especially for currently available double-stent bioprosthetic valves. Due to the complex structure of the double-stent, the irregular shape of the inner stent, and the numerous skirt structures, most existing valves are unable to meet the requirements of double-stent "Valve-in-Valve" surgery.

[0005] It is to be understood that the information provided in the Background section of the present application is merely intended to provide an overview of the general background of the application and should not be considered as an admission that the information constitutes prior art to the present application. SUMMARY

[0006] The present application aims to provide an artificial valve stent and artificial valve prosthesis, which are suitable for valve-in-valve surgery, and are designed to achieve stable and reliable anchoring with the original biological valve in the body through a unique anchoring structure, and can meet the valve-in-valve surgery requirements even if the original biological valve uses a double-layer stent.

[0007] To achieve the above-mentioned purpose, the present application provides an artificial valve stent for valve-in-valve surgery, which comprises:

[0008] a stent body for accommodating in an original 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 towards the other end of the artificial valve stent and extends outside the stent body laterally, and is used for clamping the original biological valve.

[0010] Optionally, one end of the artificial valve stent is an inflow end, the other end of the artificial valve stent is an outflow end, all of the positioning support arms are arranged at the inflow end, and the other end of each of the positioning support arms extends outside the stent body laterally towards the outflow end of the artificial valve stent, and is used for clamping the inflow end of the original biological valve.

[0011] Optionally, one end of the artificial valve stent is an outflow end, the other end of the artificial valve stent is an inflow end, all of the positioning support arms are arranged at the outflow end, and the other end of each of the positioning support arms extends outside the stent body laterally towards the inflow end of the artificial valve stent, and is used for clamping the outflow end of the original biological valve.

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

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

[0014] Optionally, it further comprises a plurality of barbs protruding from the lateral outer wall of the stent body, and the barbs and the positioning support arms are oppositely arranged.

[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 split 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 the 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 above.

[0019] The artificial valve stent mentioned above 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 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 and is used to clamp the original biological valve. After being configured in this way, the present invention can achieve valve-in-valve replacement for the original biological valve that has been 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 by multiple positioning support arms to achieve positioning and anchoring. This structure is simple, accurate in positioning, uncomplicated in surgical operation and highly reliable, and has a small size, which does not affect the positioning performance of the original biological valve in the body.

[0020] Since the artificial valve prosthesis provided in this application and the artificial valve stent provided in this application belong to the same inventive concept, the artificial valve prosthesis provided in this application has all the advantages of the artificial valve stent provided in this application. Therefore, the beneficial effects of the artificial valve prosthesis provided in this 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 one embodiment of the present invention, wherein a positioning support arm is provided at the inflow end of the artificial valve stent;

[0023] Figure 2 yes Figure 1 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 1 is a schematic diagram of an application scenario of a mitral valve-in-valve replacement performed by delivering an artificial valve stent through a delivery system according to an embodiment of the present invention, wherein a positioning support arm is provided at the inflow end of the artificial valve stent;

[0026] Figure 5 1 is a schematic diagram of a scenario in which an artificial valve stent is placed 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 1 is a schematic diagram of an application scenario of a mitral valve-in-valve replacement performed by delivering an artificial valve stent through a delivery system according to another embodiment of the present invention, wherein a positioning support arm is provided at the outflow end of the artificial valve stent;

[0028] Figure 7 Schematic diagram of placing an artificial valve stent in an existing biological valve in vivo by positioning a support arm on the outflow end of the existing biological valve, according to another embodiment of the present invention;

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

[0030] Figure 9 2 is a partial structural diagram of a positioning support arm provided in accordance with another embodiment of the present invention, which is positioned at a position corresponding to a grid hole on a skirt. The dotted line represents the support rod on the inner side of the skirt.

[0031] Figure 10 It is a schematic diagram of the scenario of valve-in-valve replacement performed with a balloon-expandable stent 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] To make the objects, 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 drawings are all in a very simplified form and are not in exact proportions, and are only used to conveniently and clearly assist in illustrating the purpose of the embodiments of the present invention.

[0035] In this document, "top" and "bottom" are viewed from the direction of blood flow through the artificial valve prosthesis from the heart. 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 "a", "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; and "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 aortic valve, mitral valve, tricuspid valve and pulmonary valve, especially for treating 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. Moreover, 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 positioning support arms 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 laterally outward from the stent body toward the other end of the artificial valve stent. When a valve-in-valve replacement is required, the stent body is simply placed within the existing biological valve in the body, while the other ends of the positioning support arms clamp the existing biological valve, achieving 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 stent 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 stent 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, so that the force is evenly distributed and the stability is better. The number of positioning support arms 120 is three or more. Preferably, three positioning support arms 120 are used, so that the structure is not complicated and the size does 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 from the lateral outside of the stent body 110 toward the outflow end 103 of the artificial valve stent 100. 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 with 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 not only latches onto the existing bioprosthetic valve 300 in the body, but also uses its own elasticity to clamp the existing bioprosthetic valve 300. The existing bioprosthetic valve 300 is an old bioprosthetic valve that has been implanted in the body's native position. Those skilled in the art can refer to the existing art to understand the structure of the existing bioprosthetic valve 300, and this application will not further explain it.

[0044] See also Figure 4 and Figure 5 When the positioning support arm 120 is set at the inflow end 101 of the artificial valve stent 100 and 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 Figure 9 .

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

[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, 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 300.

[0047] Furthermore, the outer diameter of the stent body 110 after deployment is larger than the inner diameter of the original bioprosthetic valve 300 after deployment in vivo, allowing the stent body 110 to utilize its own radial expansion force for support, further reducing the risk of displacement of the stent body 110 relative to the original bioprosthetic valve 300. Here, the inner diameter of the original bioprosthetic valve 300 after deployment in vivo is the inner diameter squeezed by 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 a double-layer stent or a 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 with a double-layer stent. Figure 5 As shown, when using a double-layer stented bioprosthesis 300, the stent body 110 is placed within the inner stent 310 of the bioprosthesis 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 deployment is larger than the inner diameter of the inner stent 310 after deployment in vivo, so that the stent body 110 provides support force in its own radial direction. The inner diameter of the bioprosthesis 300 after deployment in vivo is the same as the inner diameter of the inner stent 310 after deployment in vivo.

[0050] Furthermore, 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 valve 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 oriented in opposite directions, and the two are arranged opposite to each other. The barbs 130 can be straight or curved or other shapes, and are not specifically limited. The barbs 130 are not limited to being disposed on the grid nodes of the support body 110; barbs 130 may also be disposed on the mesh rods between the grid nodes. No fewer than three barbs 130 are arranged circumferentially around the support body 110, with the barbs 130 generally oriented toward the inflow end 101 or the outflow end 103 to prevent slippage. Neither the barbs 130 nor the positioning support arm 120 can be too long. If the barbs 130 are too long, they will not penetrate easily, while if the positioning support arm 120 is too long, it will be easily 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 constrained by the conveying system 200 and unfolds automatically after being released 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 to the original bioprosthesis 300, providing a strong anchor for the stent body 100 to prevent axial movement.

[0053] The positioning support arm 120 can be integrally formed and connected to the bracket body 110, or can be separately formed and connected to the bracket 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 bracket 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 bracket body 110 and can provide an elastic clamping function.

[0054] The positioning support arm 120 can be smoothly connected to the stent body 110 or non-smoothly connected to the stent body 110. 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 damage to the tissue at the connection site. 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, the stent body 110 is provided with a plurality of connecting parts 140, and the plurality of connecting parts 140 are distributed along the circumference of the stent body 110. Preferably, the plurality of connecting parts 140 are evenly distributed along the circumference of the stent body 110. The connecting parts 140 are arranged at the inflow end 101 of the artificial valve stent 100. In one embodiment of the present invention, the connecting parts 140 and the positioning support arms 120 which are also located at the inflow end 101 are staggered and do not overlap with each other. Each connecting 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 connecting parts 140, and a more suitable number is three. It should be noted that there are many ways to structure the connecting part 140, and at least one of them can be selected to be implemented, which is explained below as an example.

[0056] like Figure 2 As shown, in this embodiment, the connecting portion 140 is a lug with a hole, which can be used, for example, to pass a control wire provided by the delivery system 200 to achieve 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. Each lug can be provided with one or two holes. The lug can optionally have a T-shaped structure, but is not limited to this. In other embodiments, the connecting portion 140 can be snap-fitted or plugged into 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 artificial valve leaflets (not shown). The artificial valve leaflets are two or three, and the artificial valve leaflets are arranged in the stent body 110. The artificial valve leaflets are made of animal pericardium or other biocompatible polymer materials. In the working state, the artificial valve leaflets replace the native valve leaflets to achieve 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 it is better to ensure that the single channel of blood flows from the inflow end 101 of the artificial valve stent 100 to the outflow end 103 of the artificial valve stent 100. 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. It 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 takes 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 usage 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 one existing structure, a double-stent bioprosthesis includes an inner stent 310 and an outer stent 320, with the inner stent 310 connected to the outer stent 320. The inner stent 310 may also include a tether 340 disposed at its bottom end, configured to be secured to the heart wall or apex. In practice, the inner stent 310 primarily supports the valve leaflets and often lacks sufficient radial anchoring force. Therefore, the outer stent 320 is used for radial anchoring, ensuring the positioning of the bioprosthesis within the native tissue. Furthermore, a skirt 330 is provided between the inner stent 310 and the outer stent 320 to seal the gap between the inner stent 310 and the outer stent 320. However, it should be noted that the structure of existing double-stent bioprosthesis is not limited to the example shown here. As will be understood by those skilled in the art, other double-stent bioprosthesis with similar or similar functions are also suitable for this application, as long as the stent body 110 can be inserted into the inner stent 310 and the positioning support arm 120 can be locked onto the top of the inner stent 310.

[0062] According to the applicant's research, the traditional valve-in-valve stent is not suitable for valve-in-valve replacement of a double-layer stented bioprosthetic valve. On the one hand, it is limited by the skirt 330 between the inner and outer stents, which makes the traditional valve-in-valve stent anchoring space small, making it difficult to achieve stable and reliable anchoring. On the other hand, it is also limited by the length of the valve frame, making it difficult to anchor in place. In addition, the excessive radial force of some valve-in-valve stents will 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, which is not easily affected by the length of the valve frame and the skirt 330. In addition, the positioning support arm 120 is smaller in size and flexible in clamping, and can adapt to any shape of the inner stent 310 (including special-shaped inner stents). At the same time, the barbs 130 penetrate the skirt 330 or the leaflets of the native valve, locking the movement in both axial directions. At the same time, the barbs 130 are short and do not affect the normal function of the leaflets of the valve-in-valve.

[0063] The specific implementation process is as follows Figure 4 and Figure 5 As shown, taking the mitral valve-in-valve surgery as an example, the delivery system 200 enters the upper part of the mitral valve through the atrial septum. Then, the tip of the delivery system 200 is adjusted to align with the original biological valve stent 300. After alignment, the delivery system 200 is further advanced 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, causing the positioning support arms 120 to be released and ejected. At this time, the bottom end of the artificial valve stent 100 is still restrained by the sheath 210, and the barbs 130 have not yet been released. After confirming that the bottom end of the artificial valve stent 100 has entered the inner stent 310, the position of the artificial valve stent 100 is adjusted so that the positioning support arms 120 clamp the inner stent 310. Then, the entire artificial valve stent 100 is fully released, allowing the barbs 130 to penetrate into the original biological valve and achieve anchoring. That is, the new artificial valve prosthesis replaces the old biological valve and begins to work. Finally, the delivery system 200 is withdrawn, completing the valve-in-valve replacement.

[0064] As can be understood, the delivery system 200 includes a sheath 210, a tapered head 220, and a catheter 230. The distal end of the catheter 230 is connected to the tapered head 220. The artificial valve prosthesis is sheathed on the catheter 230. The sheath 210 is slidably sheathed on the catheter 230 along the axial direction of the catheter 230. A storage space is formed between the sheath 210 and the catheter 230 to compress the artificial valve prosthesis. Before use, the artificial valve prosthesis is stored between the sheath 210 and the catheter 230, so that the artificial valve prosthesis can pass smoothly through the body structure during delivery. During use, the delivery system 200 is first delivered to a location such as the mitral valve. Then, the sheath 210 is removed by operating the handle to release the compression of the sheath 210 on the artificial valve prosthesis, allowing the artificial valve prosthesis to be released. 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 lumen during delivery, making delivery easier, and is made of soft plastic to prevent puncture of human tissue.

[0065] It should be understood that when the positioning support arms 120 are positioned at the outflow end 103, the delivery and release methods are essentially the same as when they are positioned at the inflow end 101. The difference is that during delivery, all positioning support arms 120 at the outflow end 103 are first released, allowing the positioning support arms 120 to be released and ejected and locked onto the outflow end of the original bioprosthetic valve 300, leaving the top end of the artificial valve stent 100 still bound by the sheath 210. After the positioning support arms 120 are anchored and clamped, the sheath 210 is withdrawn, completely releasing the entire artificial valve stent 100. Finally, the delivery system 200 is withdrawn.

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

[0067] The positioning support arm 120 of the inflow end 101 is used for schematic illustration. In one embodiment, 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 shown in FIG. Figure 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 this type of original biological valve. Figure 10This is because the front delivery portion of the balloon catheter 1 (including the balloon and tip) has a certain length and diameter, which is longer than the implant and smaller than the diameter of the original bioprosthetic valve's closure. Therefore, when the balloon-expandable stent 2 is delivered into the closure of the original bioprosthetic valve 500, the front end of the balloon catheter 1 cannot penetrate deeper into the closure, 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 certain heart valves with closure-type stent structures, such as apical tether anchoring of the original bioprosthetic valve 500.

[0069] It should be noted that those skilled in the art can make several improvements and additions without departing from the disclosure of this application, and these improvements and additions should also be considered as the scope of protection of this application. Any equivalent changes, modifications and evolutions made by those skilled in the art using the technical content disclosed above without departing from the spirit and scope of this application are equivalent embodiments of this application; at the same time, any equivalent changes, modifications and evolutions 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 laterally outside 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, wherein: 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 on the lateral outside of the stent body and is used to be positioned on the inflow end of the original biological valve.

3. The artificial valve stent according to claim 1, wherein: 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 on the lateral outside of the stent body and is used to be positioned 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 the body.

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 bracket body is provided with a plurality of barbs, the barbs protruding from the lateral outer wall of the bracket 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 split 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 according to any one of claims 1 to 9 is provided.

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