Anchoring hook, valve stent and valve prosthesis

Abstract

The application discloses an anchoring hook, a valve stent and a valve prosthesis. The anchoring hook body comprises a straight rod segment, a bending segment and a free segment arranged in sequence from a root to a head. A slit has a starting point in the root area of the straight rod segment, and the slit extends from the starting point along the length direction of the anchoring hook body through the straight rod segment, the bending segment and at least a part of the free segment. The slit penetrates the anchoring hook body in the thickness direction of the anchoring hook body, and the width of the slit in the width direction of the anchoring hook body satisfies that the bending stiffness of the anchoring hook body changes within a predetermined threshold range compared with that before the slit is formed. The anchoring hook in the application is slit on the body, and the slit can enhance the torsional compliance of the whole anchoring hook without affecting the bending stiffness of the anchoring hook body. When subjected to multi-dimensional interaction force caused by continuous contraction of the heart or subjected to torsional force that makes the anchoring hook have a lateral bending or torsional tendency, the anchoring hook in the application has good fatigue performance.

Description

An anchoring hook, valve stent and valve prosthesis Technical Field

[0001] This invention relates to the field of medical devices, specifically to an anchoring hook and a valve prosthesis using the anchoring hook. Background Technology

[0002] The heart can develop various valvular diseases due to congenital or acquired causes. These diseases can directly or indirectly affect people's physical and mental health. For example, the mitral valve, located between the left ventricle and left atrium, is susceptible to diseases such as mitral stenosis and mitral regurgitation. Mitral stenosis is characterized by a reduced mitral valve opening area, leading to restricted blood outflow. Mitral regurgitation is characterized by incomplete valvular closure, resulting in blood backflow. Similarly, the tricuspid valve, located between the right ventricle and right atrium, can cause tricuspid regurgitation (TR) when certain factors lead to tricuspid regurgitation. Severe TR can cause or worsen right heart failure, leading to increased systemic venous pressure, abdominal organ congestion, and inducing clinical manifestations such as hepatosplenomegaly, ascites, peripheral edema, chest tightness, and fatigue. Valvular diseases significantly reduce patients' quality of life and life expectancy.

[0003] Currently, percutaneous minimally invasive surgery is rapidly developing, and transcatheter interventional treatment for valvular diseases is mainly divided into two categories: repair and replacement. Transcatheter tricuspid valve repair techniques mainly include annulusoplasty and edge-to-edge repair. Annulusoplasty reduces the diameter of the valve annulus by implanting a shrinking device. Edge-to-edge repair uses a clamping device to hold the valve leaflets to reduce regurgitation. Transcatheter tricuspid valve replacement (TTVR) involves delivering an artificial valve to the in situ tricuspid valve via a catheter and releasing it to replace the function of the diseased valve. Its core structural features include stent design and anchoring structure. The stent often uses a self-expanding nickel-titanium alloy stent to adapt to the large tricuspid valve annulus (diameter often >40mm) and dynamic deformation; the anchoring structure relies on radial support force to fit the valve annulus, and some designs are supplemented with barbs or anchoring arms for anchoring.

[0004] Edwards has disclosed a self-expanding tricuspid valve prosthesis, as shown in Figure 1. It consists of a self-expanding nickel-titanium alloy stent 10, bovine pericardial leaflets (not shown due to obstruction), a woven skirt 20, and a leaflet clamping device 30. Its fixation primarily relies on the hook-shaped leaflet clamping device 30. During delivery, the clamping device is straight; after being inserted into the delivery sheath, the hooks are turned inward towards the atrium, creating a clamping force between the clamping device and the radial support of the valve stent to hold the leaflet in place. During operation, the valve prosthesis is delivered to the tricuspid valve position via the femoral vein through a multi-directional adjustable bend delivery system and then released coaxially. During valve release, the clamping device is first extended to firmly grasp the leaflet, and after position adjustment, the stent is slowly released.

[0005] In this type of valve prosthesis, which is fixed by a barbed leaflet clamp, the barbed valve clamp may twist as the clamping device is gradually released due to the obstruction of the chordae tendineae or the multidimensional interaction force brought about by the heartbeat. During the repeated compression of the heart, the root of the twisted clamp is prone to breakage. After the clamp breaks, the valve stent will cause valve displacement and deflection due to uneven force. Summary of the Invention

[0006] The purpose of this invention is to provide an anchoring hook and a valve stent and valve prosthesis using the anchoring hook. The anchoring hook provided in this application can adapt well to torsion during the release of the valve prosthesis; and after being anchored to the original valve annulus, the root of the anchoring hook is not prone to breakage under the multidimensional interaction forces brought about by the continuous contraction of the heart, exhibiting good fatigue performance. This can avoid problems such as component detachment due to breakage and valve displacement or deflection caused by uneven stress on the valve stent after the anchoring hook breaks.

[0007] To achieve the above objectives, one aspect of the present invention provides an anchoring hook, comprising:

[0008] The anchoring hook body includes a straight rod section, a bent section and a free section arranged sequentially from the root to the head;

[0009] The slit begins at the root region of the straight rod segment. The slit extends from the starting point along the length of the anchor hook body through the straight rod segment, the bent segment, and to at least a portion of the free segment. The slit penetrates the anchor hook body in the thickness direction. The width of the slit in the width direction of the anchor hook body satisfies the following condition: the change in the bending stiffness of the anchor hook body compared to before the slit is made is within a predetermined threshold range.

[0010] In feasible solutions, the width of the slit is 0.15 to 0.1 mm.

[0011] In an feasible embodiment, the slit is located at the centerline of the anchor hook body, which is parallel to its length direction.

[0012] In some feasible solutions, the free section is provided with a plurality of discontinuous strip holes distributed along the length of the anchor hook body, the slit extends to the first strip hole near the root of the free section, and the slit and the plurality of discontinuous strip holes divide the anchor hook body into a parallel, quasi-double rod structure.

[0013] In a further feasible embodiment, the junction between the bent section and the free section is a gradually expanding structure.

[0014] In a further feasible embodiment, the head of the free segment gradually expands outward to form a passivated end.

[0015] In some feasible solutions, the starting end of the slit is a hole-shaped structure.

[0016] In some feasible solutions, a symmetrically designed connecting section is provided at the root of the straight rod segment on both sides in the width direction of the straight rod segment; the hole structure is located on one side of the line connecting the centers of the two connecting sections, which is close to the root of the straight rod segment.

[0017] According to another aspect of the present invention, a valve stent is also provided, comprising:

[0018] Outer support;

[0019] An inner support is placed inside the outer support and maintains a predetermined gap with the outer support; the top of the inner support is detachably connected to the top of the outer support.

[0020] An anchoring assembly includes a plurality of anchoring hooks as described in any of the preceding claims, wherein the plurality of anchoring hooks are mounted on the bottom of the outer support or the bottom of the inner support, and each anchoring hook has a different bending angle and length than the other anchoring hooks.

[0021] According to another aspect of the present invention, a valve prosthesis is also provided, comprising a valve stent as described in the above technical solution, a suture membrane and leaflets, wherein the suture membrane surrounds the outer stent and the inner stent to form a sealed structure or a non-sealed structure; the leaflets are fixedly connected to the suture membrane at the sidewall of the inner stent.

[0022] Compared with the prior art, the valve prosthesis of the present invention has the following beneficial effects:

[0023] The anchoring hook in this application has a slit in its body, which divides the torsional cross-section of the anchoring hook body into two parts. The torsional stiffness of each individual rod is less than that of the anchoring hook body without the slit. Because the slit design reduces the torsional cross-sectional area of ​​the anchoring hook body under torsional force, the overall torsional stiffness of the anchoring hook body is reduced. Therefore, the anchoring hook body with the slit can better adapt to torsion.

[0024] Meanwhile, the slit size design does not affect the bending stiffness of the anchor hook. Therefore, the anchor hook provided in this application can enhance the overall torsional compliance of the anchor hook without affecting the anchoring effect. When subjected to the multidimensional interaction forces brought about by the continuous contraction of the heart, causing it to have a tendency to bend or twist, the anchor hook in this application has good fatigue performance. Its root is not prone to fracture, avoiding problems such as component detachment due to fracture and valve displacement caused by uneven stress after fracture. Attached Figure Description

[0025] Figure 1 is a schematic diagram of the structure of a self-expanding tricuspid valve prosthesis in the prior art;

[0026] Figure 2 is a structural design diagram of an anchoring hook according to an embodiment of this application;

[0027] Figure 3 is a schematic diagram of the state of an anchoring hook after it has been shaped according to an embodiment of this application;

[0028] Figure 4 is a schematic diagram of an anchoring hook connecting a valve stent according to an embodiment of this application;

[0029] Figure 5a is a schematic diagram of a hole structure in a first position and the corresponding torsional cross-sectional area when subjected to torsion, according to an embodiment of the present application;

[0030] Figure 5b is a schematic diagram of a hole structure in a second position and the corresponding torsional cross-sectional area when subjected to torsion, according to another embodiment of this application;

[0031] Figure 6 is a schematic diagram of an anchoring hook constituting a control group according to an embodiment of this application;

[0032] Figure 7 is a schematic diagram of an anchoring assembly consisting of multiple anchoring hooks installed on a valve stent according to an embodiment of this application.

[0033] Figure 8 is a schematic diagram showing the angle between the anchoring hook body and the valve stent axis according to some embodiments of this application;

[0034] Figure 9 is a schematic diagram of a valve stent according to an embodiment of this application.

[0035] Figure label:

[0036] 100-Anchor hook body; 110-Straight rod section; 111-Connecting section; 120-Bent section; 122-First gradually expanding structure; 130-Free section; 131-Strip hole; 132-Second gradually expanding structure; 200-Slit; 210-Hole structure; 300-Expandable stent; 700-Anchoring component; 800-Valve stent; 810-Outer stent; 820-Inner stent; 830-Anchor hook; 840-Protrusion; 850-Suture membrane. Detailed Implementation

[0037] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0038] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0039] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0040] The terms “bottom,” “top,” “lower,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0041] Unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0042] As used herein, the singular forms “a,” “an,” and “the” include plural objects unless otherwise expressly stated. The terms “first,” “second,” and “third” are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The term “or” is generally used to include the meaning of “and / or” unless otherwise expressly stated.

[0043] As used in this article, the term "axial" refers to the axial direction of the support body, "above" means directly above, "vertical projection" refers to the projection along the axial direction, and "lateral projection" refers to the projection along a direction parallel to the axial direction.

[0044] As used in this article, the term "contact" refers to direct physical contact between two parties.

[0045] Cardiac Physiology

[0046] The following description of the anatomy of the heart helps to understand some of the inventive concepts disclosed herein.

[0047] In humans and other vertebrates, the heart typically comprises a muscular organ with four pumping chambers, where blood flow is controlled at least in part by various cardiac valves (i.e., the aortic valve, mitral valve, tricuspid valve, and pulmonary valve). These valves can be configured to open and close in response to pressure gradients present during various phases of the cardiac cycle (e.g., diastole and systole) to at least partially control blood flow to corresponding areas of the heart and / or blood vessels (e.g., pulmonary vessels, aorta, etc.).

[0048] The mitral and tricuspid valves, located in the connective tissue between the atria and ventricles, are collectively known as atrioventricular valves. Both valves consist of four parts: leaflets, annulus, chordae tendineae, and papillary muscles. The leaflets act as the "valve" between the atria and ventricles. The atrial-valve junction is the connection between the atria and leaflets; the most important structure here is the fibrous annulus, typically D-shaped rather than circular, primarily used to secure the leaflets. The papillary muscles are located at the base of the mitral and tricuspid valves; the chordae tendineae are thin connective tissue cords connecting the papillary muscles to the atrioventricular valves, providing traction on the leaflets. When the ventricle contracts, the papillary muscles contract, closing the mitral and tricuspid valve leaflets to prevent backflow of blood into the atria, while the chordae tendineae prevent the leaflets from flipping into the atria. When the ventricle relaxes, the papillary muscles relax, opening the mitral and tricuspid valve leaflets to allow blood to flow smoothly back into the atria.

[0049] The chordae tendineae plexus beneath the atrioventricular valves is typically densely distributed. During transcatheter mitral or tricuspid valve replacement (TMVR / TTVR) procedures, large, calcified, or abnormally thickened chordae tendineae may occupy the anatomical space of subvalvular devices (such as the subvalvular left ventricular inflow tract or the subvalvular right ventricular cavity), forming a "mesh barrier." This can hinder the passage of the delivery system or interfere with the full deployment of the prosthesis, leading to positioning deviations or lateral bending / torsion of the clamping components (such as barbs, hooks, and clamping arms) in the clamping device. When laterally bent or tortuous clamping components are subjected to the multidimensional interaction forces from the continuous beating of the heart, their roots are prone to breakage. After the clamping component breaks, the valve stent, due to uneven stress, can cause valve displacement and deflection.

[0050] In view of the shortcomings of the prior art, this application discloses an anchoring hook, a valve stent using the anchoring hook, and a valve prosthesis. The anchoring hook, valve stent, and valve prosthesis can be used in transcatheter mitral or tricuspid valve replacement surgery.

[0051] Anchor hook

[0052] The anchoring hook includes an anchoring hook body 100 and a slit 200 formed in the anchoring hook body 100. The anchoring hook body 100 in this application is shaped after production. Referring to Figure 2, Figure 2 is a structural design drawing (also known as a cutting drawing) of an anchoring hook before production according to an embodiment of this application. Figure 3 is a schematic diagram of the anchoring hook after shaping according to an embodiment of this application. Referring to Figures 2 and 3, the anchoring hook body 100 includes a straight rod segment 110, a bent segment 120, and a free segment 130 arranged sequentially from the root to the head. The starting point of the slit 200 is located in the root region of the straight rod segment 110. The slit 200 extends from the starting point along the length direction of the anchoring hook body 100, passing through the straight rod segment 110, the bent segment 120, and extending to at least a portion of the free segment 130. The slit 200 penetrates the anchoring hook body 100 in the thickness direction. The anchoring hook is in a bent state after shaping.

[0053] In an embodiment of an anchor hook with a slit 200, the slit 200 on the anchor hook body reduces the torsional cross-section and torsional stiffness of the anchor hook body. The slit in the anchor hook body divides it into a double-bar structure in the width direction. When the anchor hook body is subjected to lateral torque, the slit divides the torsional cross-section of the anchor hook body into two parts. Since the torsional cross-section of each bar is smaller than that of the unslit anchor hook body, the torsional stiffness of each bar is also smaller than that of the unslit anchor hook body. Because the slit reduces the torsional cross-sectional area of ​​the anchor hook body under torsional force, the overall torsional stiffness of the anchor hook body is reduced, thus the slit anchor hook body can better adapt to torsion.

[0054] In some embodiments, the anchor hook body 100 may be made of nickel-titanium alloy. This application does not specifically limit the material used to manufacture the anchor hook body 100; any material that enables the anchor hook to meet structural requirements falls within the scope of protection of this application.

[0055] The width of the slit in the width direction of the anchor hook body satisfies the following condition: the change in the bending stiffness of the anchor hook body compared to before the slit is within a small range. In specific implementations, the smaller the change in bending stiffness compared to before the slit, the better. After the anchor hook is applied to structures such as valve stents and inserted into the designated anatomical position, its function is to clamp and anchor the native tissue through the bending stiffness of the anchor hook. Therefore, while reducing the torsional stiffness of the anchor hook, it is not desirable for its bending stiffness to change significantly after the slit is opened. The best effect is that the bending stiffness is almost unaffected after the slit is opened. In some feasible embodiments, the change in bending stiffness compared to before the slit is between 0% and 2%.

[0056] In some embodiments, the width of the slit 200 is 0.15–0.1 mm. Slits 200 within this range include, but are not limited to, cutting using a laser cutter. The width of the slit 200 is affected by the size of the cutting spot, the diameter of which is equal to the width of the slit. Compared to the width of the anchor hook body 100, the width of the slit 200 is very small and has almost no impact on the flexural strength of the anchor hook body 100. When subjected to the multidimensional interaction forces caused by the continuous beating of the heart, the bending stiffness of the anchor hook body 100 is almost unaffected. That is, after the anchor hook is in its original state, its ability to resist bending deformation remains almost unchanged when subjected to multidimensional interaction forces such as heartbeats, thus maintaining good anchoring performance.

[0057] In some feasible embodiments, the free segment 130 is provided with a plurality of discontinuous strip-shaped holes 131, and the slit 200 extends to the first strip-shaped hole 131 near the root of the free segment 130. The slit 200 and the plurality of discontinuous strip-shaped holes 131 divide the anchor hook body into a parallel, quasi-double-bar structure. It should be noted that the root and head mentioned in this application refer to the two ends of a component. For example, the two ends of the free segment 130 along the length direction of the anchor hook body are the root and head of the free segment 130; the two ends of the straight rod segment 110 along the length direction of the anchor hook body are the root and head of the straight rod segment 110; and the two ends of the entire anchor hook body along its length direction are the root and head of the anchor hook body. In this application, the root of the anchor hook body coincides with the root of the straight rod segment 110.

[0058] Referring to Figure 2, the example of a free segment 130 with three slotted holes 131 is explained below. The portion where the free segment 130 intersects the bent segment 120 has a first gradually expanding structure 122 that gradually widens along the length of the anchoring hook body 100. The head of the free segment 130 gradually widens outward to form a blunt end, i.e., forming a second gradually expanding structure 132. The design of the first and second gradually expanding structures 122 and 132 in the free segment 130 increases the contact area between the free segment and the original structure, thereby increasing the anchoring area and improving the anchoring effect. The blunt end of the head of the free segment 130 is designed with a gradually expanding trend to avoid the head of the free segment 130 being too sharp and increasing the risk of insertion into the ventricular wall. Furthermore, the slotted holes 131 make the free segment 130 also a quasi-double-rod structure, which allows for better sewing and fixing of the skirt fabric.

[0059] In one feasible embodiment, the starting end of the slot 200 is configured as a perforated structure 210. Designing the starting point of the slot 200 as a perforated structure aims to mitigate the strain concentration problem at the root of the anchor hook. It should be noted that the perforated structure 210 at the starting segment of the slot 200 can be adaptably selected as circular, square, semi-circular, etc. This application does not specifically limit the shape of the perforated structure; any opening shape that can avoid strain concentration at the root of the anchor hook falls within the protection scope of this application.

[0060] Referring again to Figure 2, symmetrically designed connecting sections 111 are provided at the root of the straight rod segment 110, on both sides of the straight rod segment 110 in the width direction. These connecting sections 111 can be used to connect with stent connectors such as valvular stents. Figure 4 is a schematic diagram of an anchoring hook connecting a valvular stent according to an embodiment of this application. Referring to Figure 4, the connecting sections 111 on both sides of the straight rod segment 110 are used to connect the expandable stent 300 and form an integral structure with the expandable stent 300. When the valvular stent structure includes an inner stent and an outer stent, the anchoring hook can be connected to the inner frame of the valvular stent via the connecting sections 111, or it can be connected to the outer frame of the valvular stent via the connecting sections 111.

[0061] The hole structure on the anchor hook body 100 is located on one side of the line connecting the centers of the two connecting sections 111, close to the root of the straight rod section 110. The position of the hole structure 210 prevents root strain concentration during the release of the anchor hook and during the use of the frame. The reason is as follows:

[0062] Figures 5a-5b are schematic diagrams illustrating the torsional cross-sectional area of ​​a perforated structure at different positions and under torsion according to embodiments of this application. Referring to Figure 5a, the line connecting the centers of the two connecting sections 111 can be seen as the dashed line L in Figure 5a. The center of the perforated structure is located on the side of the dashed line L near the head of the straight rod segment 110, and the center of the perforated structure 210 is located on the dashed line l, that is, the starting end of the slit begins at the dashed line l. When the anchoring hook is subjected to torsional force during the release of the valve prosthesis or when the anchor body is subjected to multidimensional interaction forces caused by the continuous contraction of the heart, the torsional cross-sectional area of ​​the anchoring hook body at the root decreases sharply at the dashed line l, as shown in the schematic diagram of the torsional cross-sectional area on the right side of Figure 5a. Due to the sharp decrease in the torsional cross-sectional area, the strain at the root of the straight rod segment 110 is abnormally concentrated, which makes the anchoring hook body prone to breakage at the dashed line l.

[0063] The hole structure is positioned close to the root of the straight rod segment 110, as shown in Figure 5b. That is, the starting end of the slit is located close to the root of the straight rod segment 110. When the anchor hook is subjected to torsional force during the release of the valve prosthesis or when the anchor body is subjected to multidimensional interaction forces caused by the continuous contraction of the heart, the torsional cross-sectional area of ​​the anchor hook body at the root tends to decrease slowly, as shown in the schematic diagram of the torsional cross-sectional area on the right side of Figure 5b. Because the torsional cross-sectional area decreases slowly, the strain at the root of the straight rod segment 110 will not be abnormally concentrated due to the rapid change in cross-sectional area. Therefore, the anchor hook body is not easy to break even when subjected to a large torsional force.

[0064] In some embodiments, the slit 200 is located at the centerline of the anchor hook body 100, parallel to its length direction. That is, the slit 200 divides the anchor hook body 100 into two equal-width double-bar structures in the width direction. Because the widths are equal, when the anchor hook body 100 is torn, the slit 200 reduces the overall torsional cross-sectional area of ​​the anchor hook body, thus significantly reducing the torsional stiffness of both individual bars constituting the double-bar structure, and consequently significantly reducing the root strain of the anchor hook body 100. In some embodiments, the maximum root strain of the anchor hook is reduced to 2.3%-3.8% when subjected to torsion. Finite element analysis shows that the improved maximum root strain decreased from 7% to 2.4% (a reduction of 64%).

[0065] The following experimental data further illustrates the characteristics of the anchor hook in this application in terms of bending stiffness and root strain.

[0066] Referring to Figure 6, the anchor hooks without slots in the straight section 110 and the bent section 120 are used as a control group for comparison.

[0067] Under the same boundary conditions and the same load (which is set according to the actual physical condition of the human body), the same rotation direction and rotation angle are applied to the anchor hook body 100 and the anchor hook body in the control group. The maximum strain of the entire anchor hook body is shown in Table 1.

[0068] Table 1 compares the maximum strain of the anchor hook body in the slotted and unslotted structures.

[0069]

[0070] As shown in Table 1, the maximum strain of the anchor hook body with the slotted structure decreases significantly compared to the anchor hook body without slots, regardless of whether the angle is positive 90 degrees or negative 90 degrees.

[0071] The reaction forces of the anchor hook body without slots and the anchor hook body with slots are shown in Table 2 under the conditions of applying downward pressure to the bent section of the anchor hook body and applying downward pull to the head end of the free section in its original state, with the same downward pressure or pull and the same displacement.

[0072] Table 2 is a comparison of the reaction forces of the anchor hook body in the slotted and unslotted structures.

[0073]

[0074]

[0075] As shown in Table 2, the reaction forces of the anchor hook bodies with and without slots are very similar. Under the same working conditions, the reaction force of the anchor hook body with slots is almost unchanged compared with that without slots. Correspondingly, the change in bending stiffness of the anchor hook body with slots is very similar compared with that without slots, and can be approximated as the bending stiffness being almost unchanged.

[0076] As can be seen from the above technical content and experimental data, the anchor hook body in this application has a slit at its root, which divides the anchor hook body into a double-bar structure in the width direction. When the anchor hook body is torsion, the torsional cross-sectional area at the root of the anchor hook body changes slowly, thus reducing the strain at the root of the anchor hook body. After anchoring to the original valve annulus, when the anchor hook of this structure is subjected to the multidimensional interaction force brought about by the continuous contraction of the heart, the slit design reduces the torsional cross-sectional area of ​​the anchor hook body under torsional force, thus reducing the overall torsional stiffness of the anchor hook body. Therefore, the anchor hook body after the slit can better adapt to torsion, avoiding problems such as component detachment due to fracture and valve displacement and deflection caused by uneven stress on the valve stent after the anchor hook breaks. At the same time, the size design of the slit does not affect the bending stiffness of the anchor hook. Therefore, the anchor hook provided by this application can enhance the overall torsional compliance of the anchor hook without affecting the anchoring function.

[0077] Anchoring components

[0078] The anchoring assembly includes multiple anchor hooks, which are installed at the bottom of the valve stent. When the valve stent includes an outer stent and / or an inner stent structure, the multiple anchor hooks can be disposed on the outer stent or the inner stent. Figure 7 is a schematic diagram of an anchoring assembly consisting of multiple anchor hooks installed on a valve stent according to an embodiment of this application. Referring to Figure 7, the anchoring assembly 700 includes multiple anchor hooks. The multiple anchor hooks have different bending angles and lengths. The bending angle and length of each anchor hook are different from those of the other anchor hooks.

[0079] In a preferred embodiment, each anchoring hook is integrally formed with the valve stent. This arrangement can reduce the sewing process of the valve stent, enhance the connection strength with the valve stent, and reduce the risk of the valve stent coming off the hook.

[0080] The anchoring assembly consists of anchoring hooks of different lengths forming an anchoring hook combination, i.e., the anchoring assembly. The bending angle of each anchoring hook in the anchoring assembly is designed according to the original site to be adapted. Since the anchoring hooks in the anchoring assembly improve the adaptability, the anchoring assembly described in this application enables the valve stent to be firmly anchored at the original site.

[0081] In some embodiments, the number of anchor hooks is 6-9, as shown in Figure 8 in some embodiments. The angle α between the centerline of the straight rod segment 110 of the anchor hook body 100 and the axis of the valve stent ranges from 20-50°.

[0082] According to another aspect of this application, a valve stent is also provided. Figure 9 is a schematic diagram of a valve stent structure according to an embodiment of this application. Referring to Figure 9, the valve stent 800 in this application includes an outer stent 810 and an inner stent 820. An anchoring hook 830 is disposed on the outer stent 810.

[0083] The outer stent 810 in this embodiment has a compressed state and an expanded state. In some embodiments, the outer stent 810 is a hollow mesh structure with openings at both ends, which has the characteristic of being compressible and expandable. When the valve stent of the embodiment is used to perform transcatheter tricuspid / mitral valve intervention, the maximum radial support profile of the outer stent 810 is the same as or similar to the profile of the tricuspid or mitral valve annulus, and its size is larger or slightly larger than the original annulus, forming a radial interference structure relative to the original annulus. This allows the valve prosthesis using this stent to achieve a good fit with the original valve position. In some embodiments, the maximum support profile of the outer stent 810 is 1.05-1.2 times the profile of the original annulus.

[0084] In some embodiments, the outer stent 810 is provided with needles, one end of which is connected to the outer surface of the outer stent 810, and the other end is inclined toward the outer side of the outer stent 810. The needles on the outer stent 810 can penetrate into the native tissue after the valve stent is delivered to the predetermined position, so that the valve stent can be more firmly fixed at the native valve annulus.

[0085] The material forming the outer scaffold 810 can be selected from metals such as nickel-titanium, titanium alloy, cobalt-chromium alloy, MP35n, 316 stainless steel, L605, Phynox / Elgiloy (cobalt-chromium-nickel alloy), platinum-chromium, or other biocompatible metals known to those skilled in the art.

[0086] Alternatively, the outer support 810 may also be made of a material that is elastically or plastically deformable, such as an expandable balloon, or may be a shape memory alloy that responds to temperature changes to transition between a contracted delivery state and an expanded deployment state.

[0087] The inner scaffold 820 is a cylindrical structure open at both ends. This cylindrical structure has the characteristic of being compressible and expandable. The vertical projection of the inner scaffold 820 is circular or annular; or the vertical projection of the inner scaffold 820 is elliptical or quasi-elliptical. This application does not specifically limit the shape of the vertical projection of the inner scaffold 820. The inner scaffold 820 may adopt a layout structure with the same outline as and parallel to the outer scaffold 810. In some embodiments, the main body of the inner scaffold 820 has multiple cutouts, which can be circular, grid-shaped, rhomboid, or other patterns. The material forming the inner scaffold 820 can be selected from metals such as nickel-titanium, titanium alloy, cobalt-chromium alloy, MP35n, 316 stainless steel, L605, Phynox / Elgiloy (cobalt-chromium-nickel alloy), platinum-chromium, etc., or other biocompatible metals known to those skilled in the art.

[0088] The inner support 820 is a cylindrical structure open at both ends, with an anchor point (obscured in Figure 9 due to angle) at the top for connection with the outer support 810. In some embodiments, the anchor point is a ring-shaped structure with a central opening. In some embodiments, the protrusion 840 of the outer support 810 is a ring-shaped structure with a central opening, located at the top of the outer support 810. The outer support 810 is sleeved on the outside of the inner support 820, and the connection method between the protrusion 840 on the inner support 820 and the anchor point on the outer support 810 includes one or more combinations of welding, riveting, crimping, and sewing.

[0089] In one embodiment, the inner support 820 and the outer support 810 can also be connected by flexible binding straps (e.g., metal or non-metal wires).

[0090] In some embodiments, the anchoring hook body is provided with a radiopaque point. During the process of the valve stent being inserted into the interventional catheter and released from the interventional catheter into the native valve annulus, the spatial shape and trajectory of the anchoring hook can be displayed through the radiopaque point, thereby achieving better capture and positioning of the anchoring hook.

[0091] valve prosthesis

[0092] In another aspect, the present invention provides a valve prosthesis, as shown in Figure 9, comprising a valve stent 800, a suture membrane 850, and valve leaflets (not shown due to obstruction), wherein the suture membrane surrounds the valve stent to form a sealing structure.

[0093] In another embodiment of the valve prosthesis, the valve prosthesis includes a valve stent 800, a suture membrane 850, and leaflets (not shown due to obstruction). The suture membranes are respectively disposed on the inner stent and the outer stent, and the suture membranes on the inner stent and the outer stent are independently surrounded to form a non-sealed structure on the valve stent.

[0094] In some embodiments, the suture membrane may be made of biocompatible and easily endothelialized materials such as PET (polyethylene terephthalate), PTFE (polytetrafluoroethylene), ePTFE (expanded polytetrafluoroethylene), and PU (polyamide), or biological tissue materials such as porcine pericardium or bovine pericardium.

[0095] The suture membrane can be a densely meshed shape made of yarns such as PET, PTFE, ePTFE, and PU, provided that it can prevent blood flowing through the valve prosthesis from flowing out of the side wall of the outer stent 810.

[0096] Optionally, the suture membrane can be connected to the outer or inner wall of the outer support 810, for example, by binding with non-metallic wires.

[0097] In some embodiments, the leaflets are fixedly connected to a suture membrane wrapped around the sidewall of the inner support 820.

[0098] Optionally, the leaflets are sutured to a suture membrane wrapped around the sidewall of the inner support 820.

[0099] The valve prosthesis consists of two or three artificial leaflets. One end of each leaflet is stably connected to the suture membrane on the sidewall of the inner stent 820, while the other end is a free end. In operation, the artificial leaflets replace the native leaflets to open and close the blood flow channels.

[0100] The materials used to manufacture the leaflet assembly include biological tissue materials or synthetic materials. For example, biological tissue materials can be any one of bovine pericardium, sheep pericardium, pig pericardium or horse pericardium tissue, and synthetic materials can be polyurethane, polytetrafluoroethylene or organosilicon polyester, etc.

[0101] The valve prosthesis has two forms: a compressed state and an inflated state. Unless otherwise specified, the descriptions in this invention refer to the inflated state.

[0102] Obviously, many modifications and variations can be made based on the content of this specification. These embodiments have been selected and specifically described in this specification to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to make good use of the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. An anchoring hook, characterized in that, include: An anchor hook body includes a straight rod segment, a bent segment, and a free segment arranged sequentially from the root to the head; symmetrically designed connecting sections are provided at the root of the straight rod segment on both sides in the width direction of the straight rod segment; a slit, the starting point of which is located in the root region of the straight rod segment, the slit extends from the starting point along the length direction of the anchor hook body through the straight rod segment and the bent segment to at least a portion of the free segment, the slit penetrates the anchor hook body in the thickness direction, and the width of the slit in the width direction of the anchor hook body satisfies the following condition: the change in bending stiffness of the anchor hook body compared to before the slit is opened is within a predetermined threshold range; a hole structure is opened at the starting end of the slit and located on one side of the line connecting the centers of the two connecting sections, this side being close to the root of the straight rod segment, the opening position of the hole structure can prevent root strain concentration of the anchor hook during release and use.

2. The anchoring hook according to claim 1, characterized in that, The width of the slit is 0.15~0.1mm.

3. The anchoring hook according to claim 1, characterized in that, The slit is located at the center line of the anchor hook body, which is parallel to its length direction.

4. The anchoring hook according to claim 1, characterized in that, The free section is provided with a plurality of discontinuous strip holes distributed along the length of the anchor hook body. The slit extends to the first strip hole near the root of the free section. The slit and the plurality of discontinuous strip holes divide the anchor hook body into a parallel, double-rod-like structure.

5. The anchoring hook according to claim 1, characterized in that, The junction between the bent section and the free section has a gradually expanding structure.

6. The anchoring hook according to claim 5, characterized in that, The head of the free segment gradually expands outward to form a blunt end.

7. A valve stent, characterized in that, include: An outer support; an inner support, placed inside the outer support and maintaining a predetermined gap between them; the top of the inner support is detachably connected to the top of the outer support; an anchoring assembly, comprising a plurality of anchoring hooks as described in any one of claims 1 to 6, the plurality of anchoring hooks being installed at the bottom of the outer support or the bottom of the inner support, each anchoring hook having a different bending angle and length than the other anchoring hooks.

8. A valve prosthesis, characterized in that, The valve includes the valve stent of claim 7, as well as a suture membrane and leaflets, wherein the suture membrane surrounds the outer stent and the inner stent to form a sealed structure or a non-sealed structure; the leaflets are fixedly connected to the suture membrane at the sidewall of the inner stent.

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