Prosthetic valve fixation device and valve replacement device comprising same

Abstract

The present application relates to a prosthetic valve fixation device for fixing a prosthetic valve to a leaflet of a native valve, comprising: an inner stent having an open proximal end, an open distal end, and a tubular sidewall extending between the open proximal end and the open distal end along a longitudinal axis of the prosthetic valve fixation device; and an outer stent having a three-dimensional ring shape extending in an axial curvature and configured to be fitted radially outside the inner stent; wherein the inner stent and the outer stent are configured to clamp each leaflet of the native valve between the inner stent and the outer stent to fix the prosthetic valve fixation device on a leaflet of a native valve, and wherein the outer stent is fixedly connected to the inner stent in an axial direction along the longitudinal axis. The present application also relates to a valve replacement device comprising the above-mentioned prosthetic valve fixation device.

Description

Technical Field

[0001] One aspect of this application relates generally to an artificial valve fixation device, and more particularly, to a device for fixing an artificial valve to a native valve. Another aspect of this application relates to a valve replacement device incorporating the aforementioned artificial valve fixation device. Background Technology

[0002] Valvular diseases are common cardiovascular diseases, including malformations, stenosis, calcification, insufficiency, and regurgitation caused by congenital malformations, acquired diseases, and aging. These valvular diseases alter the normal hemodynamics of blood, leading to a range of symptoms such as palpitations, shortness of breath, fatigue, edema, angina, and syncope after exertion. In particular, aortic valve calcification, stenosis, insufficiency, and regurgitation are common valvular diseases.

[0003] For patients with aortic valve calcification and stenosis, transcatheter aortic valve implantation (TAVI) has become a common treatment in recent years. In TAVI, an interventional delivery device (such as a sheath) is used to deliver a balloon to the aortic valve region via, for example, the femoral artery. The balloon is radially inflated to displace the native valve and expose the annulus. An artificial valve (such as one made from porcine pericardium) is then contracted and contained within the interventional delivery device and delivered to the aortic valve region via, for example, the femoral artery. Upon reaching the aortic valve region, the balloon, again encased within the artificial valve fixation device, is radially inflated to force the device to expand radially, thereby radially supporting it within the aortic valve annulus. After removal of the balloon and interventional delivery device, the implanted artificial valve replaces the function of the native valve, opening and closing with the contraction and relaxation of the left ventricle. Because the annulus of the native aortic valve in patients with aortic valve calcification and stenosis can provide a strong reaction force for the radial support of the artificial valve fixation device, the aforementioned artificial valve fixation device can be firmly fixed within this type of annulus.

[0004] However, in patients with isolated aortic regurgitation (without aortic stenosis or calcification), the annular tissue of the native aortic valve is usually too soft to provide sufficient radial support. In such cases, it is often difficult to use the aforementioned prosthetic valve fixation device to secure the prosthetic valve to the native annulus through radial support. Furthermore, in patients with bicuspid aortic valve malformation accompanied by isolated regurgitation without stenosis or calcification, the aforementioned prosthetic valve fixation device is also difficult to use due to the typically soft annular tissue. Therefore, in the field of valve replacement devices, there is a need for prosthetic valve fixation devices with improved fixation methods, as well as valve replacement devices incorporating such devices, to address the problem of securing prosthetic valves in patients with valvular diseases without stenosis or calcification (such as isolated aortic or pulmonary valve regurgitation). Summary of the Invention

[0005] The artificial valve fixation device and valve replacement device including the present application, according to embodiments of this application, at least partially solve the above-mentioned problems and other problems discussed below. One aspect of this application relates to an artificial valve fixation device for fixing an artificial valve to the leaflets of a native valve. The artificial valve fixation device may include an inner stent and an outer stent. The inner stent may have a proximal opening, a distal opening, and a tubular sidewall extending along the longitudinal axis of the artificial valve fixation device between the proximal and distal openings. The outer stent may have a three-dimensional annular shape extending axially and may be configured to be fitted radially outside the inner stent. The inner and outer stents may be configured to clamp each leaflet of the native valve between the inner and outer stents to fix the artificial valve fixation device to the leaflets of the native valve. The outer stent may be connected to the inner stent in an axial direction along the longitudinal axis. By clamping the leaflets of the native valve, the artificial valve fixation device according to this application can position the carried artificial valve using the leaflets of the native valve, without relying on radial support forces to support it on the inner circumference of the valve annulus. Therefore, it is suitable for patients with valvular disease without calcification or stenosis. The overall three-dimensional annular shape of the outer stent allows it to "wrap" around the leaflets of the native valve from the outside, while the inner stent can push the leaflets towards the outer stent from the inside. In addition, the outer stent is fixedly connected to the inner stent in the axial direction along the longitudinal axis, eliminating axial relative movement between the inner and outer stents during implantation, thereby simplifying the complexity of the interventional delivery device and the implantation process, and reducing the risk of operational failure.

[0006] In some embodiments, the external stent is configured such that, after being radially compressed from an extended state to a compressed radial dimension under radial compressive force, the external stent at least partially self-expands to restore its original radial dimension in the extended state when the radial compressive force is removed from the external stent. By virtue of the self-expanding property of the external stent, the external stent of the artificial valve fixation device according to this application can at least partially self-restore its diameter when extended distally from the interventional delivery device during implantation. Therefore, only the circumferential angle of the artificial valve fixation device needs to be adjusted before capturing the leaflets of the native valve, without the need to use expansion devices such as balloons to restore or enlarge the diameter of the external stent.

[0007] In some embodiments, the outer diameter of the external support in its deployed state is not greater than the inner diameter of the valve annulus of the native valve, and the outer diameter is preferably 15mm to 30mm. The artificial valve fixation device according to this application does not rely on radial support force to support itself on the inner circumference of the valve annulus, thus ensuring that the artificial valve fixation device does not shift while avoiding any additional damage to the valve annulus.

[0008] In some embodiments, the external support is made of a shape memory material or a superelastic material. In some embodiments, the shape memory material is a shape memory nickel-titanium alloy. Shape memory nickel-titanium alloys, such as nitinol, have excellent shape memory properties, allowing the external support to largely recover to its original diameter in its unfolded state, such as recovering to more than 90%, preferably more than 95%, more preferably more than 99%, and most preferably completely recovering to its original diameter. Furthermore, this material also exhibits excellent biocompatibility to reduce rejection reactions.

[0009] In some embodiments, the three-dimensional annular shape of the external stent includes at least two distal protrusions, each of which is used to clamp a corresponding leaflet of the native valve between the corresponding distal protrusion and the internal stent. During implantation, the external stent laterally covers the leaflet of the native valve in a distal direction from proximal to distal. The distal protrusions face the leaflet distally to capture it within the space between the external stent and the contracted internal stent.

[0010] In some embodiments, each of at least two distal protrusions has a “U” shape. The “U” shape has rounded edges to avoid damaging or irritating the leaflets of the native valve.

[0011] In some embodiments, each pair of adjacent distal protrusions in at least two distal protrusions are joined together at the proximal connection portion to connect them to form a complete three-dimensional annular shape of the outer support.

[0012] In some embodiments, the proximal connection portion is fixedly connected to the inner support, thereby fixing the outer support to the inner support as a whole, particularly in the axial direction along the longitudinal axis.

[0013] In some embodiments, the outer support can be connected to the inner support by wire stitching or binding, welding or fusion.

[0014] In some embodiments, the stent has a compressible mesh structure to facilitate retraction and containment within an interventional delivery device such as a sheath.

[0015] In some embodiments, the stent is configured such that, after being radially compressed from an extended state to a compressed state under the action of a radial compressive force, the stent remains at least partially compressed when the radial compressive force is removed from the stent. During implantation, as it extends distally from the interventional delivery device, the external stent of the artificial valve fixation device according to this application can at least partially self-restore its diameter, while the internal stent can at least partially remain compressed at its diameter, thereby preserving space between them for capturing the leaflets of the native valve.

[0016] In some embodiments, the stent is configured such that, when a radially outward force is applied to the stent while it is in a compressed state, it radially expands from a compressed state to an expanded state. After the leaflets of the native valve are captured in the space between the stent and the outer stent, the outer diameter of the stent can be expanded to near the inner diameter of the outer stent by means of the radial expansion of a device such as a balloon disposed inside the stent, thereby clamping the leaflets between the two.

[0017] In some embodiments, the inner support is made of a non-shape memory material (i.e., a material that does not have shape memory properties or superelasticity), such as a cobalt-chromium alloy or stainless steel. Inner supports made of these materials are able to retain their compressed dimensions after being compressed and the compressive force is removed, and are able to recover their expanded dimensions when an expansion force is applied.

[0018] Another aspect of this application relates to a valve replacement device, including an artificial valve fixation device and an artificial valve according to any of the above embodiments. The periphery of the artificial valve is fixed to the inner surface of an inner stent. In some embodiments, the artificial valve may be made of natural materials such as porcine pericardium or bovine pericardium, or artificially synthesized biocompatible synthetic materials. Attached Figure Description

[0019] The following description, with reference to the accompanying drawings, illustrates various embodiments of an artificial valve fixation device and a valve replacement device according to this application. As used herein, the term "artificial valve" refers to a membranous one-way valve structure made of natural materials such as porcine pericardium or bovine pericardium, or of biocompatible synthetic materials, and which functions to open and close in response to the contraction and relaxation of the corresponding ventricles and atria of the heart, excluding any device for fixing the structure to the implantation site; the term "artificial valve fixation device" refers to a device for carrying such an "artificial valve" and fixing it to the implantation site; and the term "valve replacement device" refers to the entire assembly of such an "artificial valve fixation device" and such an "artificial valve," wherein the periphery of the "artificial valve" can be fixed to the inner side of the "artificial valve fixation device."

[0020] It should be understood that the accompanying drawings are for illustrative and explanatory purposes only and are not intended to limit the scope of protection of this application. Furthermore, the drawings only schematically show the positions and assembly relationships of the components and are not necessarily drawn to scale, wherein:

[0021] Figure 1 This is a schematic perspective view of an artificial valve fixation device in an deployed state according to an embodiment of this application;

[0022] Figure 2 This is a schematic perspective view of an artificial valve fixation device in a compressed state according to an embodiment of this application;

[0023] Figure 3 This is a schematic perspective view illustrating the valve replacement device retracting within the interventional delivery device according to an embodiment of this application;

[0024] Figure 4 This is a schematic perspective view illustrating a valve replacement device extending from an interventional delivery device according to an embodiment of this application;

[0025] Figure 5A This is a schematic perspective view of a valve replacement device according to an embodiment of the present application during the leaflet capture process;

[0026] Figure 5B This is a schematic bottom view illustrating a valve replacement device according to an embodiment of this application during the leaflet capture process;

[0027] Figure 5C This is a schematic bottom view of a valve replacement device according to another embodiment of this application during the leaflet capture process;

[0028] Figure 6A This is a schematic perspective view illustrating a valve replacement device according to an embodiment of the present application during the leaflet clamping process;

[0029] Figure 6B This is a schematic bottom view illustrating a valve replacement device according to an embodiment of the present application during the leaflet clamping process;

[0030] Figure 6C This is a schematic bottom view of a valve replacement device according to another embodiment of this application during the leaflet clamping process;

[0031] Figure 7A This is a schematic perspective view of the valve replacement device according to an embodiment of this application after implantation.

[0032] Figure 7B This is a schematic bottom view of a valve replacement device according to an embodiment of this application after implantation.

[0033] Figure 7C This is a schematic bottom view of a valve replacement device according to another embodiment of this application after implantation.

[0034] In some of these accompanying drawings, some components may have been omitted for purposes such as clarity of illustration or to avoid obscuring the view. This should not be construed as indicating that the corresponding components are not included in the illustrated embodiments. Detailed Implementation

[0035] The following detailed description, with reference to the accompanying drawings, illustrates an artificial valve fixation device and a valve replacement device including the same, and their implantation process, according to embodiments of the present application, wherein the same reference numerals refer to the same or corresponding elements in several views. As used herein, the term "far" refers to a direction in which the artificial valve fixation device, valve replacement device, interventional delivery device (such as a sheath), or its components are farther from the operator (such as a physician) (e.g., as shown in the schematic three-dimensional figures). Figure 1 , 2 The lower left and each schematic three-dimensional Figure 3 , 4 The lower right of 5A, 6A, and 7A; specifically, for the aortic valve, it indicates the direction perpendicular to the aortic valve plane from the aorta to the left ventricle, while the term "near" refers to the direction in which the artificial valve fixation device, valve replacement device, implantable device, interventional delivery device (such as a sheath), or its components are closer to the operator (such as a physician) (e.g., as shown in the schematic three-dimensional diagrams). Figure 1 , 2 The upper right and each schematic three-dimensional Figure 3 , 4The upper left of 5A, 6A, and 7A; specifically, for the aortic valve, it indicates the direction perpendicular to the aortic valve plane from the left ventricle to the aorta. In other words, during the implantation process, the "distal" end of the artificial valve fixation device, valve replacement device, implantable device (such as an interventional delivery device like a sheath), or internal stent, external stent, etc., is the end that enters the patient's body first, while the "proximal" end is the other end that enters the patient's body later. In this application, "valve" is used interchangeably with other valves such as the aortic valve and pulmonary valve, because the artificial valve fixation device and valve replacement device according to this application can be applied to repair various valves, only requiring adjustment of the specific configuration of the internal and external stents according to the number, size, shape, and treatment needs of the valve leaflets being treated. Therefore, while the following may explain the structure, function, role, and beneficial effects of the artificial valve fixation device and valve replacement device according to this application in the context of the treatment of bicuspid aortic valve malformation (hereinafter used interchangeably with "bicuspid valve"), it should be understood that these components, their role, and beneficial effects are equally applicable to the repair treatment of other valvular diseases.

[0036] One aspect of this application relates to an artificial valve fixation device 100. Figure 1 This is a schematic perspective view illustrating an artificial valve fixation device 100 in its deployed state according to an embodiment of this application. Figure 1 As shown, the artificial valve fixation device 100 may include an outer stent 120 and an inner stent 140, with the outer stent 120 radially fitted over the outer side of the inner stent 140. The inner stent 140 may have a proximal opening 146, a distal opening 142, and a tubular sidewall 144 extending along the longitudinal axis of the artificial valve fixation device 100 between the proximal opening 146 and the distal opening 142. The outer stent 120 may have a three-dimensional annular shape. In other words, the outer stent 120 generally surrounds the outer side of the inner stent 140, but the annular structure of the outer stent 120 may not be in the same plane, but may include distal and / or proximal undulations along the longitudinal axis of the artificial valve fixation device 100 to form an annular shape in three-dimensional space to facilitate capturing and clamping the leaflets of the native valve, as will be described in more detail below with reference to the accompanying drawings. In other words, the external support 120 can appear as a continuous ring in a top view along the longitudinal axis, while in a side view along the radial direction, it can present a non-planar structure that bulges distally and / or proximally along the longitudinal axis. By holding the leaflets of the native valve between the internal support 140 and the external support 120, the artificial valve fixation device 100 can position the carried artificial valve in the location of the native valve by means of the native leaflets, without relying entirely on radial support forces to support it on the inner circumference of the native valve annulus.

[0037] In some embodiments, the outer stent 120 may be fixedly connected to the inner stent 140 in the axial direction along the longitudinal axis. In this case, no significant axial relative movement will occur between the outer stent 120 and the inner stent 140 when changing between a contracted state (e.g., radially compressed to contract and be contained within the interventional delivery device) and an deployed state (e.g., extended from within the interventional delivery device and deployed to prepare for leaflet capture). Accordingly, the interventional delivery device does not need to be equipped with components for separately delivering and releasing the outer stent 120 and the inner stent 140, thereby simplifying the complexity of the interventional delivery device and the implantation process, and avoiding the impact of increased delivery outer diameter on delivery efficiency. In addition, this avoids relative axial position errors or misalignments that may be introduced when the outer stent 120 moves axially relative to the inner stent 140, thus reducing the risk of implantation failure. In some embodiments, the outer stent 120 may be axially fixedly sutured or bound to the inner stent 140 by a fine thread such as nickel-titanium wire, or may be completely fixedly connected to the inner stent 140 by means of fusion, welding, etc.

[0038] Figure 2 This is a schematic perspective view illustrating an artificial valve fixation device 100 in a compressed state according to an embodiment of this application. Figure 2 As shown, under radial compressive force, both the inner support 140 and the outer support 120 of the artificial valve fixation device 100 shrink to a smaller radial dimension in the radial direction. Still referring to... Figure 2 In some embodiments, since the outer support 120 can be fixedly connected to the inner support 140 in the axial direction along the longitudinal axis, it is compatible with... Figure 1 Compared to the deployed state, the relative axial position between the outer stent 120 and the inner stent 140 remains unchanged in the contracted state. Applying radial compressive force to the artificial valve fixation device 100 can be done using existing or yet-to-be-developed devices in the art, such as gripping devices or loading tools, to allow it to contract and be accommodated within an interventional delivery device such as a sheath. Figure 3 As shown. In some embodiments, the inner stent 140 in its contracted state may have an inflatable device, such as a balloon, inserted through its inner periphery, as will be described in more detail below with reference to the accompanying drawings.

[0039] In some embodiments, the artificial valve fixation device 100 contracts to the size of a radial compressive force. Figure 2 Following the contracted state, when the radial compressive force is removed from the artificial valve fixation device 100 (e.g., when the artificial valve fixation device 100 is extended distally from an interventional delivery device such as a sheath during implantation), the external stent 120 can self-inflate to at least partially return to its original position. Figure 1The original radial dimensions in the deployed state are shown. Due to its self-expanding properties, the outer support 120 of the artificial valve fixation device 100 according to this application can at least partially restore its diameter when extended from the distal end of the interventional delivery device during implantation, and each portion of the outer support 120 can at least partially restore its original shape in the deployed state. Therefore, only the circumferential angle of the artificial valve fixation device 100 needs to be adjusted before capturing the leaflets of the native valve, without the need to use expansion devices such as balloons to restore or enlarge the diameter of the outer support 120. Understandably, this simplifies the steps required during the implantation process and shortens the surgical time, thereby improving patient outcomes.

[0040] In some embodiments, the outer support 120 is made of a shape memory material or a hyperelastic material. In some embodiments, the shape memory material is a shape memory alloy, such as a shape memory nickel-titanium alloy, or a shape memory nickel-titanium alloy such as Nitinol, which has good shape memory properties. Alternatively, the outer support 120 may also be made of other shape memory materials or hyperelastic materials that are existing in the art or yet to be developed and have biocompatibility and durability, such as metals or polymers with shape memory or hyperelastic properties. The shape memory or hyperelastic properties of the material enable the outer support 120 to have the aforementioned self-expanding properties, that is, after the radial compressive force is removed, it can largely recover to its original radial dimensions in the unfolded state, such as recovering to more than 90%, preferably more than 95%, more preferably more than 99%, and most preferably completely recovering to the original diameter.

[0041] In some embodiments, the three-dimensional annular shape of the outer stent 120 may include at least two distal protrusions 122, each distal protrusion 122 projecting distally along the longitudinal axis of the artificial valve fixation device 100 in a radially lateral view. The distal protrusions 122 are used to capture and hold the corresponding leaflet of the native valve between themselves and the inner stent 140. During implantation, the outer stent 120 may laterally enclose the leaflet of the native valve in a distal direction from proximal to distal. The distal protrusions 122 may face the leaflet distally to capture it within the space between the outer stent 120 and the retracted inner stent 140, as will be referred to laterally. Figure 4-6C More detailed description. In some embodiments, each distal protrusion 122 may have a "U" shape, wherein the curved bottom of the "U" shape extends distally along the longitudinal axis. The "U" shape has rounded edges to avoid damage to or irritation to the leaflets of the native valve. In some embodiments, such as Figure 1 As shown, each pair of adjacent distal protrusions 122 can be connected together at the corresponding proximal connecting portion 124 to form a complete three-dimensional annular shape of the outer support 120. In some embodiments, such as Figure 1 As shown, each proximal connection portion 124 can be loosely or tightly sewn / bound with metal wire, or fixedly connected to the outer periphery of the inner support 140 by means of fusion, welding, etc., so that the outer support 120 is fixedly connected to the inner support 140 in the axial direction along the longitudinal axis.

[0042] Additionally, in some embodiments, the at least two distal protrusions 122 of the three-dimensional annular shape of the external support 120 may include a pair of opposing distal protrusions 122, which are connected together at a pair of proximal connecting portions 124, such as... Figure 1 and Figure 2 As shown. In this case, the pair of opposing distal protrusions 122 can be used to capture and hold the corresponding leaflet of the pair of leaflets between themselves and the inner stent 140. Therefore, the artificial valve fixation device 100 according to these embodiments is particularly suitable for the treatment of valvular diseases with two leaflets, such as the treatment of simple regurgitation bicuspid aortic valve malformation without stenosis or calcification. Even if the annulus of the bicuspid aortic valve in the patient with this disease is too soft for radial support alone to install the artificial valve fixation device 100, the artificial valve fixation device 100 according to these embodiments can also position the artificial valve at the location of the native aortic valve by holding the pair of leaflets between the pair of opposing distal protrusions 122 of the outer stent 120 and the inner stent 140.

[0043] In some embodiments, the three-dimensional annular shape of the outer support 120 forms part of the tubular sidewall 144 in the unfolded state. In other words, in, for example... Figure 5B , Figure 5C , Figure 6B , Figure 6C , Figure 7B and Figure 7C In the bottom view shown, viewed from the far side to the near side, the outer support 120 in its deployed state appears annular. As an example, the three-dimensional annular shape of the outer support 120 can be formed by cutting a cylindrical tube of material using processes such as laser cutting. Alternatively, when the inner wall of the native valve annulus deviates significantly from a cylindrical shape, a tube of material simulating the shape of the native valve annulus can also be cut to form the three-dimensional annular shape of the outer support 120. In this case, when the artificial valve fixation device 100 is implanted with its longitudinal axis perpendicular to the plane of the native valve, the three-dimensional annular shape of the outer support 120 in its deployed state can generally best match the shape of the inner wall of the native valve annulus, as will be referred to later. Figure 7A More detailed description.

[0044] Since it does not require radial support force to be applied to the inner circumference of the native valve annulus, the artificial valve fixation device 100 according to embodiments of this application can be used to treat valvular diseases without stenosis or calcification, even if the native valve annulus is too soft to provide sufficient reaction force for radial support of the artificial valve fixation device 100. Accordingly, in some embodiments, the outer diameter of the external stent 120 in the deployed state may not be greater than the inner diameter of the native valve annulus, thus generating virtually no radial outward support force after implantation to avoid any additional damage to the annulus. In other words, after implantation, the outer diameter of the external stent 120 may be exactly equal to the inner diameter of the native valve annulus to fit within the annulus without generating a radial expansion force on the annulus, or only generating a small radial expansion force; alternatively, the outer diameter of the external stent 120 may be slightly larger or slightly smaller than the inner diameter of the native valve annulus to facilitate positioning and manipulation during implantation. It is understood that the diameter of the external stent 120 should also not be too small to avoid paravalvular leakage. Preferably, the outer diameter of the outer support 120 in the unfolded state is 15mm to 30mm. Thus, when the inner diameter of the valve annulus of the original valve is fixed, the outer diameter of the artificial valve fixation device 100 in the embodiment of this application is smaller than the outer diameter of the artificial valve stent required in the prior art.

[0045] In some embodiments, the tubular sidewalls 144 of the stent 140 may have a mesh-like structure to improve radial compressibility, thereby allowing for easier retraction and reception within the interventional delivery device with a smaller delivery profile. In some embodiments, the mesh-like structure, in its unfolded state, may consist of polygonal meshes such as hexagonal meshes, quadrilateral meshes, or combinations thereof. It is understood that, compared to meshes of stable shapes such as triangular meshes, stents 140 composed of hexagonal and quadrilateral meshes are more easily compressed to a smaller radial dimension or expanded back to their original radial dimension.

[0046] In some embodiments, the inner stent 140 may be configured to remain at least partially compressed after being radially compressed from an extended state to a compressed state under the action of radial compressive force, when the radial compressive force is removed from the inner stent. In other words, the inner stent 140 does not have self-expanding properties, or at least does not spontaneously and completely expand back to its original radial dimensions in the extended state. During implantation, as it extends distally from the interventional delivery device, the outer stent 120 of the artificial valve fixation device 100 may at least partially and spontaneously return to its original diameter in the extended state, while the inner stent 140 may at least partially remain in its compressed radial dimensions without spontaneously and completely expanding back to its original radial dimensions in the extended state, thereby preserving space between the inner stent 140 and the outer stent 120 for capturing the leaflets of the native valve, as will be referred to later. Figures 4-5C More detailed description.

[0047] In some embodiments, the stent 140 can be configured such that, when a radially outward force is applied to the inner surface of the stent 140 in a compressed state, the stent 140 can radially expand from its compressed state to its original radial dimension in an expanded state. After the leaflets of the native valve are captured in the space between the stent 140 and the outer stent 120, the outer diameter of the stent 140 can be expanded to near the inner diameter of the outer stent 120 by means of the radial expansion of a device such as a balloon disposed inside the stent 140, thereby clamping the leaflets between them, as will be referred to below. Figures 6A-6C More detailed description.

[0048] In some embodiments, the stent 140 may be made of a non-shape memory material. In other words, the material used to manufacture the stent 140 may not possess self-expanding properties, shape memory properties, or superelasticity. In some embodiments, the material may be a cobalt-chromium alloy or stainless steel, or a high-stiffness material with biocompatibility and durability that is existing in the art or yet to be developed. It is understood that a stent 140 made of these materials can at least partially retain its radial dimensions in the compressed state after being compressed and the compressive force is removed, and can recover its radial dimensions in the expanded state when an expansion force is applied.

[0049] In some embodiments, the inner stent 140 and / or outer stent 120 may be coated with a biocompatible coating, such as polyethylene terephthalate (PET), to improve biocompatibility, reduce rejection reactions, and promote endothelialization.

[0050] Another aspect of this application relates to a valve replacement device comprising the artificial valve fixation device 100 and the artificial valve as described in any of the embodiments above. In some embodiments, the periphery of the artificial valve may be fixed to the inner surface of the inner support 140 to form an integral structure with the artificial valve fixation device 100 and the annulus of the original valve to achieve the function of the repaired valve. In some embodiments, the artificial valve may have, for example, three leaflets and be sutured to the inner surface of the inner support 140 at several points around its periphery, or be fixed to the inner surface of the inner support 140 by a structure such as a base (not shown). In some embodiments, the artificial valve may be made of a material membrane existing in or yet to be developed in the art, such as natural materials like porcine pericardium or bovine pericardium, or biocompatible and durable synthetic materials.

[0051] The following is for reference Figures 3-7CThis document explains the implantation process of the artificial valve fixation device 100 and the valve replacement device comprising the artificial valve according to this application. Although the procedure for treating aortic valve bicuspidation is described in these figures and the following description, and the artificial valve fixation device 100 is illustrated and described as comprising a pair of distal protrusions 122, the artificial valve fixation device 100 and the valve replacement device according to this application may also comprise a greater number (e.g., three) of distal protrusions 122 and be used to treat valvular diseases of valves with three leaflets (such as aortic valves, pulmonary valves, tricuspid valves, etc., without bicuspidation). Additionally, in these figures, illustrations of the artificial valve may have been omitted for clarity and to avoid obstruction; only the artificial valve fixation device 100 is shown. This does not imply that an artificial valve is not included in these implantation procedures.

[0052] Figure 3 This is a schematic perspective view illustrating a valve replacement device retracted within an interventional delivery device 200 according to an embodiment of this application. Figure 3 In the contracted state shown, the valve replacement device is delivered to the vicinity of the aortic valve via a minimally invasive surgical procedure such as femoral artery intervention, using an interventional delivery device 200 such as a sheath. Figure 3 As shown, the artificial valve fixation device 100 is radially compressed to its contracted size and retracted within the interventional delivery device 200. At this time, both the inner stent 140 and the outer stent 120 of the artificial valve fixation device 100 can be radially compressed, and the inner stent 140 and outer stent 120 are positioned near the distal end of the interventional delivery device 200, such as a sheath. Although not shown, the artificial valve of the valve replacement device can also retract within the inner stent 140 at this time. Additionally, an expansion device such as a balloon can be fitted inside the retracted inner stent 140. Figure 3 (not shown) so that the non-self-expanding stent 140 can be inflated in subsequent operations to return to its radial dimensions in the deployed state. In some embodiments, a balloon may be attached to the distal end of a catheter (not shown) to form a balloon catheter, and the balloon catheter may also move axially along a guidewire (not shown) to deliver the valve replacement device and sheath to the target site.

[0053] Figure 4This is a schematic perspective view illustrating the valve replacement device extending from the interventional delivery device 200 according to an embodiment of this application. As an example, upon reaching the target position, the valve replacement device can be extended distally from the sheath via distal movement of the balloon catheter relative to the sheath. It should be understood that the valve replacement device remains proximal to the aortic valve at this time, i.e., on the aortic side and not crossing the aortic valve plane to the left ventricular side. At this time, due to the self-expansion properties of the shape memory material or hyperelastic material of the outer stent 120, the outer stent 120 self-expands to at least partially restore its original radial dimensions in the deployed state, while the inner stent 140 remains at least partially in its contracted radial dimensions in the contracted state. In this case, by rotating the valve replacement device, a pair of distal protrusions 122 of the outer stent 120 of the artificial valve fixation device 100 can be circumferentially aligned with a pair of native leaflets of the bicuspid aortic valve to prepare for capture of the native leaflets.

[0054] Figure 5A This is a schematic perspective view illustrating a valve replacement device according to an embodiment of this application during the leaflet capture process. Figure 5A As shown, after completing the above reference Figure 4 Following the described extension and alignment operations, the valve replacement device is moved distally (in the case of the aortic valve, from the aorta toward the left ventricle) until the distal ends of the external stent 120 and / or the internal stent 140 are substantially abutted against the proximal side (i.e., the aortic side) of the aortic valve, so that the pair of native leaflets are fitted into the space between the pair of distal protrusions 122 of the deployed external stent 120 and the contracted internal stent 140. At this point, the external stent 120 can substantially engage with the annulus 300 of the aortic valve, but does not rely on the radial support force between the external stent 120 and the annulus 300 to secure the artificial valve fixation device 100.

[0055] Figure 5B This is a schematic bottom view (viewed from the left ventricle towards the aorta, taking the aortic valve as an example) of a valve replacement device according to an embodiment of this application during the leaflet capture process. Figure 5B As shown, the inner stent 140, together with the artificial valve 500, is fitted onto the periphery of an inflator 400, such as a balloon, while the outer stent 120 has self-inflated to a radial dimension close to or equal to the inner diameter of the valve annulus 300. In this embodiment, the outer stent 120 and the inner stent 140 are fixedly connected to each other only in the axial direction, and not necessarily tightly fastened together in the radial direction. As an example, the outer stent 120 can be loosely bound / sewn to the corresponding positions of the inner stent 140 with wire at a pair of proximal connecting portions 124. In this case, a radial space d1 can be provided between the distal protrusion 122 of the outer stent 120 and the inner stent 140 to accommodate the native leaflet. Additionally, as... Figure 5B As shown, the artificial valve 500 can be expanded by an inflator 400, such as a balloon, to attach to the inside of the stent 140.

[0056] Figure 5C This is a schematic bottom view (viewed from the left ventricle towards the aorta, taking the aortic valve as an example) of a valve replacement device according to another embodiment of this application during the leaflet capture process. Figure 5B Compared to the embodiments shown, Figure 5C In the illustrated embodiment, the outer stent 120 can be secured to the inner stent 140 at a pair of proximal connecting portions 124 by means such as fusion, welding, or tight binding / sewing with wires. Therefore, when the outer stent 120 extends out of the sheath and self-inflates, the inner stent 140 also inflates at least partially in the direction corresponding to the pair of proximal connecting portions 124 of the outer stent 120. In contrast, the inner stent 140 remains at least partially in its contracted radial dimension in the direction corresponding to the pair of distal protrusions 122 of the outer stent 120, leaving a radial space of d2 between itself and the distal protrusions 122 of the outer stent 120 for accommodating the leaflets that capture the native valve. It is understood that in this case, the artificial valve 500 also at least partially unfolds along with the inner stent 140 in the direction corresponding to the pair of proximal connecting portions 124 of the outer stent 120, and remains abutting against the uninflated balloon.

[0057] Figure 6A This is a schematic perspective view illustrating a valve replacement device according to an embodiment of the present application during the leaflet clamping process, wherein the artificial valve is omitted to show the arrangement of the balloon. After capturing and positioning a pair of native leaflets in the space between a pair of distal protrusions 122 of the deployed outer stent 120 and the retracted inner stent 140, as Figure 6A As shown, an inflator 400, such as a balloon, enlarged radially within the inner stent 140, expands the inner stent 140 radially to at least partially restore its deployed state, thereby securely clamping the captured native leaflets v1, v2 between the outer stent 120 and the inner stent 140. Thereafter, the native leaflets v1, v2, being clamped, will remain in an open state and will no longer perform the valve opening and closing function, and the valve replacement device will be fixed at the location of the native valve by clamping the native leaflets v1, v2.

[0058] Figure 6B This is a schematic bottom view (viewed from the left ventricle towards the aorta, taking the aortic valve as an example) of a valve replacement device according to an embodiment of this application during the leaflet clamping process. Figure 5B The illustrated embodiments correspond to, in Figure 6BIn the illustrated embodiment, the outer support 120 can be loosely bound / sewed to the corresponding position of the inner support 140 with wire at a pair of proximal connecting portions 124. For example... Figure 6B As shown, in Figure 6A During the leaflet clamping process shown, an inflator 400, such as a balloon, expands, causing the inner stent 140 to expand radially until it approaches the inner diameter of the outer stent 120. At this time, the radial space between the inner stent 140 and the pair of distal protrusions 122 of the outer stent 120 decreases to d3, so as to securely clamp the captured native leaflets v1, v2 between the inner stent 140 and the distal protrusions 122. It can be understood that during this process, the artificial valve 500 is pushed by the inflator 400 against the inner wall of the inner stent 140. After this process, by clamping the native leaflets v1, v2, the artificial valve fixation device 100, together with the carried artificial valve 500, is fixed in the position of the native valve.

[0059] Figure 6C This is a schematic bottom view (viewed from the left ventricle towards the aorta, taking the aortic valve as an example) of a valve replacement device according to another embodiment of this application during the leaflet clamping process. (Corresponding to...) Figure 5B The illustrated embodiment Figure 6B The illustrated embodiments are similar. Figure 6C The illustrated embodiments may correspond to Figure 5C In the illustrated embodiment, the outer support 120 can be fastened to the inner support 140 at a pair of proximal connecting portions 124 by means of, for example, fusion, welding, or tight binding / sewing with wire. Similarly, after the inner support 140 is expanded using the expansion device 400, the radial space between the inner support 140 and the pair of distal protrusions 122 of the outer support 120 is reduced to d4 to securely clamp the captured native leaflets v1, v2 between the inner support 140 and the distal protrusions 122.

[0060] Figure 7A This is a schematic perspective view of the valve replacement device according to an embodiment of this application after implantation, wherein the artificial valve is omitted to clearly show the stent 140 and the valve annulus 300. After clamping the native leaflets v1, v2, the inflator 400, such as a balloon, is deflated, and interventional delivery devices such as guidewires, sheaths, and balloon catheters are delivered. Figure 7A (Not shown) is removed from the patient's body. At this point, the implantation process of the valve replacement device according to an embodiment of this application is complete. After the expansion device 400 contracts, the artificial valve ( Figure 7A (Not shown) The aortic valve is restored to its normal working state by the inner wall of the stent 140, thereby replacing the function of the original aortic valve, that is, opening and closing with the contraction and relaxation of the left ventricle.

[0061] Figure 7B This is a schematic bottom view (view from the left ventricle towards the aorta, taking the aortic valve as an example) of a valve replacement device according to an embodiment of this application after implantation. Figure 5B , 6B The illustrated embodiments correspond to, in Figure 7B In the illustrated embodiment, the outer support 120 can be loosely bound / sewed to the corresponding position of the inner support 140 with wire at a pair of proximal connecting portions 124. For example... Figure 7B As shown, after implantation is completed and instruments such as the expansion device 400, guide wire, and sheath are removed, the artificial valve 500 returns to its normal working state and opens inside the inner support 140 of the artificial valve fixation device 100.

[0062] Figure 7C This is a schematic bottom view (view viewed from the left ventricle towards the aorta, taking the aortic valve as an example) of a valve replacement device according to another embodiment of this application after implantation. (Corresponding to...) Figure 5B , 6B The illustrated embodiment Figure 7B Compared to the embodiments shown, Figure 7C The illustrated embodiments may correspond to Figure 5C , 6C In the illustrated embodiment, the outer support 120 can be fastened to the inner support 140 at a pair of proximal connection portions 124 by means of, for example, fusion, welding or wire binding / sewing.

[0063] like Figure 5B , Figure 5C , Figure 6B , Figure 6C , Figure 7B and Figure 7CAs shown, since the artificial valve fixation device 100 according to this application does not rely on the radial support force between the external stent 120 and the valve annulus 300 to fix the artificial valve, the outer diameter of the external stent 120 after implantation can be no greater than the inner diameter of the valve annulus 300 of the native valve. In other words, after implantation, the outer diameter of the external stent 120 can be exactly equal to the inner diameter of the valve annulus 300 of the native valve to fit the inner circumference of the valve annulus 300 without applying a high radial expansion force to the valve annulus 300. Thus, the artificial valve fixation device 100 can be stably positioned without using a stent with high stiffness and radial support force, while maintaining good flexibility and wall apposition, thereby avoiding displacement and reducing risks such as paravalvular leakage and damage to the valve annulus. Alternatively, after implantation, the outer diameter of the external stent 120 can also be slightly larger or slightly smaller than the inner diameter of the valve annulus 300 of the native valve. Preferably, after implantation, the outer diameter of the external stent 120 ranges from 15mm to 30mm. Additionally, the implantation process is illustrated in the diagram. Figures 3-7C As shown, no axial (i.e., distal or proximal) relative movement occurs between the inner stent 140 and the outer stent 120 during the implantation process. This simplifies the complexity of the interventional delivery device 200 and the implantation procedure. Furthermore, by avoiding errors or misalignments that might be introduced by relative axial movement between the outer stent 120 and the inner stent 140, the risk of implantation failure is reduced.

[0064] It should be understood that various modifications can be made to the disclosed apparatus. Therefore, the above description should not be construed as limiting, but merely as examples of embodiments of this disclosure. Other modifications within the scope and spirit of this disclosure will be conceived by those skilled in the art. For example, any and all features of one described embodiment may be suitably integrated into another embodiment, and the beneficial effects of such features in one embodiment may be expected to be achieved in another embodiment.

Claims

1. An artificial valve fixation device, characterized in that, The artificial valve fixation device is used to fix the artificial valve to the leaflet of the native valve, including: An internal stent, having a proximal opening, a distal opening, and a tubular sidewall extending along the longitudinal axis of the artificial valve fixation device between the proximal and distal openings; and The outer support has a three-dimensional annular shape that bends and extends axially, and is configured to be fitted on the radially outer side of the inner support; The inner stent and the outer stent are configured to hold each leaflet of the native valve between the inner stent and the outer stent to fix the artificial valve fixation device to the leaflet of the native valve. The outer support is connected to the inner support in an axial direction along the longitudinal axis, the outer support extending from the proximal end to the distal end of the inner support in the axial direction; the inner support is made of a non-shape memory material and is configured such that, after being radially compressed from an unfolded state to a compressed state under the action of a radial compressive force, the inner support retains at least partially the compressed state when the radial compressive force is removed from the inner support.

2. The artificial valve fixation device according to claim 1, characterized in that, The outer support is configured such that, after being radially compressed from an expanded state to a contracted radial dimension under the action of a radial compressive force, when the radial compressive force is removed from the outer support, the outer support at least partially self-expands to restore its original radial dimension to the expanded state.

3. The artificial valve fixation device according to claim 2, characterized in that, The outer diameter of the outer support in the unfolded state is 15mm~30mm.

4. The artificial valve fixation device according to claim 2, characterized in that, The outer support is made of shape memory material or superelastic material.

5. The artificial valve fixation device according to claim 4, characterized in that, The shape memory material is a shape memory nickel-titanium alloy.

6. The artificial valve fixation device according to claim 1, characterized in that, The three-dimensional annular shape of the external stent includes at least two distal protrusions, each of which protrudes distally along the longitudinal axis to clamp the corresponding leaflet of the native valve between the corresponding distal protrusion and the internal stent.

7. The artificial valve fixation device according to claim 5, characterized in that, Each of the at least two distal protrusions has a "U" shape.

8. The artificial valve fixation device according to claim 5, characterized in that, Each pair of adjacent distal protrusions in the at least two distal protrusions are joined together at the proximal connection portion.

9. The artificial valve fixation device according to claim 8, characterized in that, The proximal connection portion is fixedly connected to the inner support.

10. The artificial valve fixation device according to claim 1, characterized in that, The outer support is connected to the inner support by stitching or binding, welding or fusion of metal wires.

11. The artificial valve fixation device according to claim 1, characterized in that, The internal support has a compressible mesh structure.

12. The artificial valve fixation device according to claim 1, characterized in that, The inner support is configured such that, when a radially outward force is applied to the inner support while it is in the compressed state, the inner support radially expands from the compressed state to the unfolded state.

13. The artificial valve fixation device according to claim 11, characterized in that, The material of the internal support is cobalt-chromium alloy or stainless steel.

14. A valve replacement device, characterized in that, include: Artificial valve fixation device according to any one of claims 1-13; as well as Artificial valve, The periphery of the artificial valve is fixed to the inner surface of the internal stent.

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