Anchoring hook, valve stent and valve prosthesis

Abstract

The invention discloses an anchoring hook, a valve stent and a valve prosthesis. The anchoring hook body comprises a straight rod section, a bent section and a free section which are sequentially arranged from the root to the head. The starting point of the open seam is located in the root area of the straight rod section, the open seam passes through the straight rod section and the bent section in the length direction of the anchoring hook body from the starting point and extends to at least one part of the free section, and the open seam penetrates through the anchoring hook body in the thickness direction of the anchoring hook body. The width of the slit in the width direction of the anchoring hook body meets the condition that the variation of the bending rigidity of the anchoring hook body is within a preset threshold value range compared with that before the slit is formed. According to the anchoring hook, slotting is conducted on the body of the anchoring hook, and the overall torsion compliance of the anchoring hook can be enhanced under the condition that the bending rigidity of the anchoring hook body is not affected through slotting. When the anchoring hook is subjected to multi-dimensional interaction force caused by continuous contraction of the heart or torsional force enabling the anchoring hook to have a lateral bending or torsional tendency, the anchoring hook has good fatigue performance.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and particularly to an anchoring hook and a valve prosthesis using the anchoring hook. Background Art

[0002] Due to congenital or acquired reasons, the heart can develop various valve diseases, which will directly or indirectly affect people's physical and mental health. For example, the mitral valve located between the left ventricle and the left atrium, valve diseases usually include mitral stenosis, mitral insufficiency, etc. Mitral stenosis is manifested as a reduction in the opening area of the mitral valve, resulting in restricted blood outflow. Mitral insufficiency is manifested as incomplete valve closure and blood reflux. Another example is the tricuspid valve located between the right ventricle and the right atrium. When some etiologies cause tricuspid insufficiency, blood flows back from the right ventricle through the insufficient tricuspid valve into the right atrium, that is, tricuspid regurgitation (TR). Severe TR causes or exacerbates right heart failure, leading to increased systemic venous pressure, congestion of abdominal organs, and inducing clinical manifestations such as hepatosplenomegaly, ascites, peripheral edema, chest tightness, and fatigue. Valve diseases lead to a significant decline in the quality of life and life expectancy of patients.

[0003] At the present stage, percutaneous minimally invasive surgery is developing rapidly. Transcatheter interventional treatment of valve diseases is mainly divided into two categories: repair and replacement. Transcatheter tricuspid repair techniques mainly include annuloplasty and edge-to-edge repair. Among them, annuloplasty reduces the annulus diameter by implanting a ring reduction device. Edge-to-Edge repair uses a clamping device to clamp the leaflets to reduce regurgitation. Transcatheter tricuspid valve replacement (TTVR) delivers an artificial valve to the original tricuspid valve through a catheter and releases it to replace the function of the diseased valve. Its core structural features include stent design and anchoring structure. The stent mostly uses a self-expanding nitinol stent, which adapts to the large tricuspid annulus (diameter often > 40 mm) and dynamic deformation; the anchoring structure relies on radial support force to fit the annulus, and some designs are supplemented with barbs or anchoring arms for anchoring.

[0004] An Edwards company publicly disclosed a self-expanding tricuspid valve prosthesis, see Figure 1 , which consists of a self-expanding nitinol stent 10, bovine pericardium leaflets (not shown due to occlusion), a woven skirt 20, and a leaflet clamping device 30. Its fixing method mainly relies on the hook-shaped leaflet clamping device 30. When in the delivery state, the clamping member is straightened. After being sent into the delivery sheath, the clamping member hooks towards the atrium, and a clamping force is formed between it and the radial support of its own valve stent to clamp the leaflets. During the operation, through the transfemoral venous approach, the valve prosthesis is sent to the tricuspid position through a multi-directionally adjustable bending delivery system and released coaxially. When the valve is released, the clamping device is first protruded to firmly grasp the leaflets, and then the valve frame is slowly released after position adjustment.

[0005] For the valve prosthesis fixed by the barb-shaped leaflet clamp, during the gradual release of the clamping device, due to the obstruction of the chordae tendineae or the multi-dimensional interaction forces brought about by the heartbeat, the barb-shaped valve clamp will twist. During the repeated compression of the heart, the root of the twisted clamp is prone to fracture. After the clamp fractures, the valve stent will cause the valve to shift and deflect due to uneven force. Summary of the Invention

[0006] The purpose of the present invention is to provide an anchoring hook, a valve stent and a valve prosthesis using the anchoring hook. The anchoring hook provided in this application can better adapt to torsion during the release of the valve prosthesis; and after being anchored to the native valve annulus, when subjected to multi-dimensional interaction forces brought about by continuous contraction of the heart, the root of the anchoring hook is not prone to fracture, has good fatigue performance, and can avoid problems such as component detachment caused by fracture and valve displacement and deflection caused by uneven force of the valve stent after the anchoring hook fractures.

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

[0008] An anchoring hook body, including a straight rod section, a bent section and a free section arranged in sequence from the root to the head;

[0009] A slit, the starting point of which is located in the root area of the straight rod section. The slit extends along the length direction of the anchoring hook body from the starting point through the straight rod section, the bent section and extends to at least a part of the free section. The slit penetrates the anchoring hook body in the thickness direction of the anchoring hook body. The width of the slit in the width direction of the anchoring hook body satisfies that the change amount of the bending stiffness of the anchoring hook body compared with that before the slit is opened is within a predetermined threshold range.

[0010] In an implementable solution, the width of the slit is 0.15 - 0.1 mm.

[0011] In an implementable solution, the slit is opened at the center line of the anchoring hook body parallel to its length direction.

[0012] In some implementable solutions, the free section is provided with a plurality of discontinuous strip holes distributed along the length direction of the anchoring 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 anchoring hook body into a parallel double-rod-like structure.

[0013] In a further implementable solution, the junction of the bent section and the free section is a gradually expanding structure.

[0014] In a further implementable solution, the head of the free section gradually expands outward to form a blunt end.

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

[0016] In some feasible embodiments, at the root of the straight rod section, connection sections with a symmetrical design are provided on both sides in the width direction of the straight rod section; the hole-shaped structure is located on one side of the central connection line of the two connection sections, and this side is close to the root of the straight rod section.

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

[0018] An outer stent;

[0019] An inner stent, placed inside the outer stent and maintaining a predetermined gap with the outer stent; the top of the inner stent is detachably connected to the top of the outer stent;

[0020] An anchoring assembly, including a plurality of anchoring hooks as described in any one of the above, and the plurality of anchoring hooks are installed at the bottom of the outer stent or the bottom of the inner stent, and the bending angles and lengths of each anchoring hook are different from those of other anchoring hooks.

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

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

[0023] In the present application, the anchoring hook is slit on its body, and the slit divides the torsional cross-section of the anchoring hook body into two parts. The torsional stiffness of each single rod is less than that of the non-slit anchoring hook body. Since the slit design can reduce the torsional cross-sectional area of the anchoring hook body when it is subjected to a torsional force, the overall torsional stiffness of the anchoring hook body is reduced. Therefore, the slit anchoring hook body can better adapt to torsion.

[0024] At the same time, the size design of the slit does not affect the bending stiffness of the anchoring hook. Therefore, the anchoring hook provided in the present application can enhance the overall torsional compliance of the anchoring hook without affecting the anchoring effect. When it has a tendency to bend or twist due to the multi-dimensional interaction force brought about by the continuous contraction of the heart, the anchoring hook in the present application has good fatigue performance, and its root is not prone to fracture, avoiding problems such as component detachment caused by fracture and valve displacement and deflection caused by uneven force after fracture. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0026] Figure 2 It is a structural design diagram of an anchoring hook shown according to an embodiment of the present application;

[0027] Figure 3 It is a schematic diagram of the state of an anchoring hook after being shaped shown according to an embodiment of the present application;

[0028] Figure 4 It is a connection schematic diagram of an anchoring hook connecting to a valve stent shown according to an embodiment of the present application;

[0029] Figure 5a It is a schematic diagram of a hole-shaped structure at a first position and the corresponding torsional cross-sectional area when being twisted shown according to an embodiment of the present application;

[0030] Figure 5b It is a schematic diagram of a hole-shaped structure at a second position and the corresponding torsional cross-sectional area when being twisted shown according to another embodiment of the present application;

[0031] Figure 6 It is a schematic structural diagram of an anchoring hook constituting a control group shown according to an embodiment of the present application;

[0032] Figure 7 It is a schematic structural diagram of an anchoring assembly composed of multiple anchoring hooks installed on a valve stent shown according to an embodiment of the present application;

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

[0034] Figure 9 It is a schematic structural diagram of a valve stent shown according to an embodiment of the present application.

[0035] Reference numerals:

[0036] 100 - anchoring hook body; 110 - straight rod section; 111 - connection section; 120 - bent section; 122 - first tapered structure; 130 - free section; 131 - strip hole; 132 - second tapered structure; 200 - slit; 210 - hole-shaped structure; 300 - expandable stent; 700 - anchoring assembly; 800 - valve stent; 810 - outer stent; 820 - inner stent; 830 - anchoring hook; 840 - bump; 850 - suture membrane. Detailed implementation manners

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

[0038] It should be clear that the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present application.

[0039] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The singular forms "a", "the", and "said" used in the embodiments of the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0040] The orientation or positional relationship indicated by terms such as "bottom", "top", "lower", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present invention.

[0041] Unless otherwise clearly defined and limited, the terms "connected" and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] As used in this specification, the singular forms "a", "an", and "the" include plural objects unless the context clearly dictates otherwise. The terms "first", "second", "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The term "or" is generally used in the sense of including "and / or" unless the context clearly dictates otherwise.

[0043] As used herein, the term "axial direction" refers to the axial direction of the stent body, "above" means directly above, the vertical projection refers to the projection along the axial direction, and the lateral projection refers to the projection along the direction parallel to the axial direction.

[0044] As used herein, the term "abut" means direct physical contact with each other.

[0045] Cardiac Physiology

[0046] The anatomical structure of the heart is described below to assist in understanding certain inventive concepts disclosed herein.

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

[0048] The mitral valve and the tricuspid valve are located in the connective tissue between the atrium and the ventricle and are collectively referred to as the atrioventricular valves. The structures of both the mitral valve and the tricuspid valve consist of four parts: leaflets, annulus, chordae tendineae, and papillary muscles. The leaflets are the "valves" between the atrium and the ventricle. The atrium-valve junction is the junction from the atrium to the leaflets, and the most important structure among them is the fibrous annulus, which is generally D-shaped rather than circular and is mainly used to fix the leaflets. The papillary muscles are located at the roots of the mitral valve and the tricuspid valve; the chordae tendineae are thin connective tissue cords connecting the papillary muscles and the atrioventricular valves and play a role in restraining the leaflets. When the ventricle contracts, the papillary muscles contract, causing the leaflets of the mitral valve and the tricuspid valve to close, preventing blood from flowing back into the atrium, and the chordae tendineae restrain the leaflets from flipping into the atrium. When the ventricle relaxes, the papillary muscles relax, causing the leaflets of the mitral valve and the tricuspid valve to open, allowing blood to flow smoothly back into the atrium.

[0049] The chordae tendineae plexus below the atrioventricular valves is usually densely distributed. During transcatheter mitral or tricuspid valve replacement (TMVR / TTVR) surgery, thick, calcified, or abnormally thickened chordae tendineae may occupy the anatomical space of the sub-valvular apparatus (such as the left ventricular inflow tract below the mitral valve or the right ventricular cavity below the tricuspid valve), forming a "mesh barrier", which in turn hinders the passage of the delivery system or interferes with the full deployment of the prosthesis, resulting in positioning deviation or bending / twisting of the clamping members (such as barbs, reverse hooks, clamping arms, etc.) in the clamping device. When the bent or twisted clamping members are continuously subjected to multi-dimensional interaction forces brought about by the heartbeat, the roots thereof are prone to breakage, and the valve stent after the breakage of the clamping member will cause valve displacement and deflection due to uneven force.

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

[0051] Anchoring 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 will be shaped after being produced. Refer to Figure 2 , Figure 2 FIG. is a structural design drawing (also known as a cutting drawing) of an anchoring hook before production according to an embodiment of the present application. Figure 3 FIG. is a schematic diagram of the state of an anchoring hook after being shaped according to an embodiment of the present application. Refer to Figure 2 and Figure 3 , the anchoring hook body 100 includes a straight rod section 110, a bent section 120, and a free section 130 arranged in sequence from the root to the head. The starting point of the slit 200 is located in the root area of the straight rod section 110. The slit 200 extends from the starting point along the length direction of the anchoring hook body 100 through the straight rod section 110, the bent section 120, and at least a part of the free section 130. The slit 200 penetrates the anchoring hook body 100 in the thickness direction of the anchoring hook body 100. The anchoring hook is in a bent state after being shaped.

[0053] In an embodiment of the anchoring hook with a slit 200, forming a slit 200 on the anchoring hook body can reduce the torsional cross-section of the anchoring hook body and lower the torsional stiffness. Making a slit on the anchoring hook body divides the anchoring hook body into a double-rod structure in the width direction. When the anchoring hook body is subjected to a lateral torque, the slit divides the torsional cross-section of the anchoring hook body into two parts. Since the torsional cross-section of each single rod is smaller than that of the anchoring hook body without a slit, the torsional stiffness of each single rod is smaller than that of the anchoring hook body without a slit. Since the slit can reduce the torsional cross-sectional area of the anchoring hook body when subjected to a torsional force, the overall torsional stiffness of the anchoring hook body is reduced. Therefore, the anchoring hook body after slitting can better adapt to torsion.

[0054] In some embodiments, the anchoring hook body 100 can be made of a nickel-titanium alloy. The present application does not specifically limit the manufacturing material of the anchoring hook body 100. Any material that can enable the anchoring hook to be shaped into the required structure falls within the protection scope of the present application.

[0055] The width of the slit in the width direction of the anchoring hook body satisfies that the change amount of the bending stiffness of the anchoring hook body compared with that before slitting is within a small change range. In specific implementation, the smaller the change amount of the bending stiffness compared with that before slitting, the better. After the anchoring hook is applied to structures such as valve stents and sent to the specified anatomical position, its function is to clamp and anchor the native tissue through the bending stiffness of the anchoring hook. Therefore, while reducing the torsional stiffness of the anchoring hook, it is not desired that the bending stiffness is greatly changed after slitting. The best effect is that the bending stiffness is hardly affected after slitting. In some feasible embodiments, the change amount of the bending stiffness compared with that before slitting is between 0-2%.

[0056] In some embodiments, the width of the slit 200 is 0.15 - 0.1 mm. The slit 200 within this numerical range includes, but is not limited to, being cut using a laser cutting machine. The width of the slit 200 is affected by the size of the cutting light spot, and the diameter of the cutting light spot is the width of the slit. Compared with the width of the anchoring hook body 100, the width of the slit 200 is very small and hardly affects the flexural strength of the cross-section of the anchoring hook body 100. When the anchoring hook of this structure is subjected to the multi-dimensional interaction forces brought about by the continuous beating of the heart, the bending stiffness of the anchoring hook body 100 is hardly affected. That is, after the anchoring hook is in its original state, when subjected to multi-dimensional interaction forces such as those brought about by heart beating, its ability to resist bending deformation remains almost unchanged, and thus it can maintain a good anchoring effect.

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

[0058] See Figure 2 , taking the example that three strip-shaped holes 131 are opened in the free section 130 for illustration. The part of the free section 130 at the junction with the bent section 120 has a first gradually expanding structure 122 that gradually expands along the length direction of the anchoring hook body 100. The head of the free section 130 gradually expands outward to form a blunt end, that is, a second gradually expanding structure 132 is formed. The design of the first gradually expanding structure 122 and the second gradually expanding structure 132 in the free section 130 can increase the contact area between the free section and the native structure, thereby increasing the anchoring area and achieving a better anchoring effect. The blunt end at the head of the free section 130 is set to have a gradually expanding trend, aiming to avoid the head of the free section 130 being too sharp and increasing the risk of inserting into the ventricular wall. In addition, the setting of the strip-shaped holes 131 makes the free section 130 also a parallel-like double-rod structure, and this structure can better sew and fix the skirt cloth.

[0059] In an implementable embodiment, the starting end of the slit 200 is provided with a hole-shaped structure 210. Designing the starting point of the slit 200 as a feature of the hole-shaped structure aims to change the problem of strain concentration at the root of the anchoring hook. It should be noted that the hole-shaped structure 210 at the starting section of the slit 200 can be adaptively selected as circular, square, semi-circular, etc. The present application does not specifically limit the shape of the hole-shaped structure. Any opening shape that can avoid strain concentration at the root of the anchoring hook falls within the protection scope of the present application.

[0060] Still referring to Figure 2 , on both sides of the root of the straight rod section 110 in the width direction of the straight rod section 110, symmetrically designed connecting sections 111 are provided. The connecting section 111 can be used to connect to a stent connecting joint such as a valve stent. Figure 4 FIG. is a schematic connection diagram of an anchoring hook connecting a valve stent according to an embodiment of the present application. Referring to Figure 4 , the connecting sections 111 on both sides of the straight rod section 110 are used to connect to the expandable stent 300 and form an integral structure with the expandable stent 300. Among them, when the structure of the valve stent includes an inner stent and an outer stent, the anchoring hook can be connected to the inner frame of the valve stent through the connecting section 111, or can be connected to the outer frame of the valve stent through the connecting section 111.

[0061] The hole-shaped structure on the anchoring hook body 100 is located on one side of the center line connecting the two connecting sections 111, and this side is close to the root of the straight rod section 110. The opening position of the hole-shaped structure 210 can prevent the phenomenon of strain concentration at the root during the release process of the anchoring hook and during the use of the valve frame. The reasons are as follows:

[0062] Figure 5a - 5b FIG. is a schematic diagram of the corresponding torsional cross-sectional area of a hole-shaped structure at different positions and when subjected to torsion according to an embodiment of the present application. Referring to Figure 5a , the center line connecting the two connecting sections 111 can be seen in Figure 5a as the dotted line L in. The center of the hole-shaped structure is located on the side of the dotted line L close to the head of the straight rod section 110, and the center of the hole-shaped structure 210 is located on the dotted line l, that is, the starting end of the slit starts at the dotted line l. When the anchoring hook is subjected to a torsional force during the release of the valve prosthesis or the anchoring body is subjected to multi-dimensional interaction forces brought about by the continuous contraction of the heart, the torsional cross-sectional area of the anchoring hook body at the root suddenly becomes smaller at the dotted line l. Referring to Figure 5a the schematic diagram of the right torsional cross-sectional area in, due to the sudden decrease in the torsional cross-sectional area, the strain at the root of the straight rod section 110 becomes abnormally concentrated, resulting in the anchoring hook body being easily broken at the dotted line l.

[0063] Make the position of the hole-shaped structure close to one side of the root of the straight rod section 110. Referring to Figure 5b, that is, the starting end of the slit is located on the side close to the root of the straight rod section 110. When the anchoring hook is subjected to a torsional force during the release of the valve prosthesis or the anchor body is subjected to multi-dimensional interaction forces brought about by the continuous contraction of the heart, the change trend of the torsional cross-sectional area at the root of the anchoring hook body is a slow decrease. Refer to Fig. Figure 5b The schematic diagram of the torsional cross-sectional area on the right side in it. Due to the slow decrease of the torsional cross-sectional area, the strain at the root of the straight rod section 110 will not cause abnormal concentration of strain at the root of the straight rod section 110 due to the sharp change of the cross-sectional area. Therefore, the anchoring hook body is not easily broken even when subjected to a large torsional force.

[0064] In some embodiments, the slit 200 is opened at the center line parallel to the length direction of the anchoring hook body 100. That is, the slit 200 bisects the anchoring hook body 100 in the width direction into two double-rod structures with the same width. Due to the same width, when the anchoring hook body 100 is twisted, the slit 200 can reduce the overall torsional cross-sectional area of the anchoring hook body. Therefore, the torsional stiffness of each of the two single rods constituting the double-rod structure decreases significantly, and the root strain of the anchoring hook body 100 decreases significantly accordingly. In some embodiments, when the anchoring hook is twisted, the maximum root strain is reduced to 2.3%-3.8%. Finite element analysis shows that after improvement, the maximum root strain decreases from 7% to 2.4% (a decrease of 64%).

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

[0066] Refer to Figure 6 In it, the anchoring hook without a slit in the straight rod section 110 and the bent section 120 is used as a control group for comparison.

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

[0068] Table 1 is a comparison table of the maximum strain of the anchoring hook body in the slit and non-slit structures.

[0069]

[0070] It can be seen from Table 1 that for the anchoring hook body with a slit structure, whether the angle of 90 degrees positive or 90 degrees negative is selected, the change in its maximum strain is significantly lower than that of the anchoring hook body without a slit.

[0071] Press down on the bent section of the anchoring hook body and pull down on the head end of the free section in its original state. Under the condition of using the same downward pressure or pulling force and the same displacement, the reaction forces of the anchoring hook body with the unsealed structure and the anchoring hook body with the slotted structure are shown in Table 2.

[0072] Table 2 is a comparison table of the reaction forces of the anchoring hook body in the slotted and unsealed structures.

[0073]

[0074]

[0075] As can be seen from Table 2, the reaction forces of the anchoring hook body with the slotted structure and the unsealed structure are very similar. Under the condition that other working conditions are the same, compared with the unsealed anchoring hook body, the reaction force of the slotted anchoring hook body hardly changes. Correspondingly, that is, compared with the unsealed anchoring hook body, the change in the bending stiffness of the slotted anchoring hook body is very close, and it can be approximately considered that the bending stiffness hardly changes.

[0076] From the above technical content and experimental data, it can be seen that the anchoring hook body in this application is slotted at its root. The slot divides the anchoring hook body into a double-rod structure in the width direction. When the anchoring hook body is twisted, the change trend of the torsional cross-sectional area at the root of the anchoring hook body is a slow change, so the strain at the root of the anchoring hook body can be reduced. After being anchored to the native annulus, when the anchoring hooks of this structure are subjected to multi-dimensional interaction forces brought about by the continuous contraction of the heart, due to the slotted design, the torsional cross-sectional area of the anchoring hook body can be reduced when it is subjected to torsional force, so the overall torsional stiffness of the anchoring hook body is reduced. Therefore, the slotted anchoring hook body can better adapt to torsion and can avoid problems such as component detachment caused by fracture and valve displacement and deflection caused by uneven force on the valve stent after the anchoring hook breaks. At the same time, the size design of the slot does not affect the bending stiffness of the anchoring hook. Therefore, the anchoring hook provided in this application can enhance the overall torsional compliance of the anchoring hook without affecting the anchoring effect.

[0077] Anchoring assembly

[0078] The anchoring assembly includes a plurality of anchoring hooks. The plurality of anchoring hooks are installed at the bottom of the stent of the valve stent. When the valve stent includes a structure of an outer stent and / or an inner stent, the plurality of anchoring hooks can be arranged on the outer stent or the inner stent. Figure 7 FIG. is a schematic structural diagram of an anchoring assembly composed of a plurality of anchoring hooks according to an embodiment of the present application installed on a valve stent. Reference can be made to Figure 7 , the anchoring assembly 700 includes a plurality of anchoring hooks. The plurality of anchoring hooks have different bending angles and lengths. The bending angle and length of each anchoring hook are different from those of other anchoring hooks.

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

[0080] The anchoring assembly is composed of anchoring hooks with different lengths to form an anchoring hook combination, that is, the anchoring assembly. The bending angle of each anchoring hook in the anchoring assembly is designed according to the native part to be adapted. Since the anchoring hooks in the anchoring assembly improve the adaptability, the anchoring assembly described in the present application can firmly anchor the valve stent at the native part.

[0081] In some embodiments, the number of the anchoring hooks is 6 - 9. In some embodiments, see Figure 8 The angle α between the center line of the straight rod section 110 of the anchoring hook body 100 and the axis of the valve stent ranges from 20° to 50°.

[0082] According to another aspect of the present application, a valve stent is further provided. Figure 9 It is a schematic structural diagram of a valve stent shown according to an embodiment of the present application. See Figure 9 , the valve stent 800 in the present application includes an outer stent 810 and an inner stent 820. The anchoring hook 830 is disposed on the outer stent 810.

[0083] The outer stent 810 in the embodiment of the present application has a compressed state and an expanded state. In some embodiments, the outer stent 810 is a hollow mesh structure with open ends at both ends, and this hollow mesh structure has the characteristics of being compressible and expandable. When the valve stent in the above - mentioned embodiment is used for 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 native annulus or the mitral native annulus, and the size is larger than or slightly larger than the native annulus, forming a radial interference structure relative to the native annulus, so that the valve prosthesis using this valve stent can form a good fitting effect with the position of the native valve. In some embodiments, the maximum support profile of the outer stent 810 is 1.05 - 1.2 times the profile of the native annulus.

[0084] In some embodiments, needles are provided on the outer stent 810. One end of the needle is connected to the outer surface of the outer stent 810, and the other end inclines towards the outside of the outer stent 810. The needles on the outer stent 810 can pierce 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 annulus.

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

[0086] Optionally, the outer stent 810 can also be made of an elastically or plastically deformable material, such as balloon-expandable, or can be a shape memory alloy that responds to temperature changes to transition between a contracted delivery state and an expanded deployed state.

[0087] The inner stent 820 is a cylindrical structure with open ends. This cylindrical structure has the characteristics of being able to be compressed and expanded. The vertical projection of the inner stent 820 is circular or annular; or the vertical projection of the inner stent 820 is elliptical or quasi-elliptical. The present application does not specifically limit the shape of the vertical projection of the inner stent 820. The inner stent 820 can adopt a layout structure that is the same as and parallel to the contour of the outer stent 810. In some embodiments, there are multiple cutouts on the main body part of the inner stent 820, which can be circular, grid-shaped, diamond-shaped, or other patterns. The material for forming the inner stent 820 can be selected from metals such as nitinol, titanium alloy, cobalt-chromium alloy, MP35n, 316 stainless steel, L605, Phynox / Elgiloy (cobalt-chromium-nickel alloy), platinum-chromium, or other biocompatible metals known to those skilled in the art.

[0088] The inner stent 820 is a cylindrical structure with open ends, and there are anchor points at the top of the cylindrical structure for point connection with the outer stent 810 ( Figure 9 obscured due to angle reasons in the figure). In some embodiments, the anchor point is an annular structure with a hole in the middle. In some embodiments, the bump on the outer stent 810 is an annular structure with a hole in the middle, and the bump 840 is located at the top of the outer stent 810. The outer stent 810 is sleeved outside the inner stent 820, and the connection methods between the bump 840 on the inner stent 820 and the anchor point on the outer stent 810 include one or a combination of welding, riveting, crimping, and suture connection.

[0089] In one embodiment, the inner stent 820 and the outer stent 810 can also be tied together by a flexible binding band (such as a metal or non-metal wire).

[0090] In some embodiments, a radiopaque marker is provided on the anchoring hook body. During the process of the valve stent being received into the interventional catheter and released from the interventional catheter to the native valve annulus, the spatial morphology and change trajectory of the anchoring hook can be displayed through the radiopaque marker, so as to achieve a better capturing and positioning effect of the anchoring hook.

[0091] Valve prosthesis

[0092] In another aspect of the present invention, there is provided a valve prosthesis, as can be seen in Figure 9 , including a valve stent 800, a suture membrane 850, and valve leaflets (not shown due to occlusion). The suture membrane surrounds the valve stent to form a sealed structure.

[0093] In another embodiment of the valve prosthesis, the valve prosthesis includes a valve stent 800, a suture membrane 850, and valve leaflets (not shown due to occlusion). The suture membranes are respectively disposed on an inner stent and an 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 material of the suture membrane may be selected from biocompatible materials that are easy to endothelialize, such as PET (polyethylene terephthalate), PTFE (polytetrafluoroethylene), ePTFE (expanded polytetrafluoroethylene), PU (polyurethane), or biological tissue materials such as porcine pericardium and bovine pericardium.

[0095] Under the condition of satisfying the function of blocking the blood flowing through the valve prosthesis from flowing out of the side wall of the outer stent 810, the suture membrane may be a grid shape with dense grid gaps made of yarns such as PET, PTFE, ePTFE, and PU.

[0096] Optionally, the suture membrane may be connected to the outer side wall or the inner side wall of the outer stent 810, for example, by tying with a non-metallic wire.

[0097] In some embodiments, the valve leaflets are fixedly connected to the suture membrane wrapped around the side wall of the inner stent 820.

[0098] Optionally, the valve leaflets are sutured to the suture membrane wrapped around the side wall of the inner stent 820.

[0099] The valve prosthesis includes two or three artificial valve leaflets. One end of the valve leaflet is stably connected to the suture membrane at the side wall of the inner stent 820, and the other end of the valve leaflet is a free end. In the working state, the artificial valve leaflets replace the native valve leaflets to realize the function of opening and closing the blood passage.

[0100] The production materials of the valve leaflet assembly include biological tissue materials or synthetic materials. For example, the biological tissue materials can be any one of bovine pericardium, sheep pericardium, porcine pericardium, or equine pericardium tissue, and the synthetic materials can be materials such as polyurethane, polytetrafluoroethylene, or silicone polyester.

[0101] The valve prosthesis has two forms: a compressed state and an expanded state. In the present invention, unless otherwise emphasized, the descriptions are all for the characteristics in the expanded state.

[0102] Obviously, many modifications and variations can be made in accordance with the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can make good use of the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. An anchoring hook, characterized in that, Comprising: An anchoring hook body, including a straight rod section, a bent section, and a free section arranged in sequence from the root to the head; A slit, the starting point of which is located in the root region of the straight rod section, and the slit extends along the length direction of the anchoring hook body from the starting point through the straight rod section, the bent section, and at least a part of the free section. 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 change amount of the bending stiffness of the anchoring hook body compared with that before the slit is opened is within a predetermined threshold range.

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

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

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

5. The anchoring hook according to claim 1, wherein, The junction of the bent section and the free section is a gradually expanding structure.

6. The anchoring hook according to claim 5, wherein, The head of the free section expands outward to form a blunt end.

7. The anchoring hook according to any one of claims 1 to 6, characterized in that, The starting end of the slit is a hole-shaped structure.

8. The anchoring hook according to claim 7, characterized in that, At the root of the straight rod section, connection sections with symmetrical design are provided on both sides in the width direction of the straight rod section; the hole-shaped structure is located on one side of the center line connecting the two connection sections, and this side is close to the root of the straight rod section.

9. A valve stent, characterized in that, Comprising: An outer stent; An inner stent, placed inside the outer stent and maintaining a predetermined gap with the outer stent; the top of the inner stent is detachably connected to the top of the outer stent; An anchoring assembly, including a plurality of anchoring hooks as described in any one of claims 1 to 8, and the plurality of anchoring hooks are installed at the bottom of the outer stent or the bottom of the inner stent, and the bending angle and length of each anchoring hook are different from those of other anchoring hooks.

10. A valve prosthesis, characterized in that, Comprising the valve stent as described in claim 9, as well as a suture membrane and leaflets, 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 side wall of the inner stent.

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