Intravascular bending-adjustable recovery hook for interventional operation

Abstract

The invention belongs to the technical field of medical instruments, and relates to an intravascular bending-adjustable recovery hook for an interventional operation. The adjustable bending recovery hook comprises a guide pipe and a hook pull rod, the hook pull rod is slidably and adjustably arranged in the guide pipe in a penetrating mode, and the front end of the hook pull rod is an elastic hook pull section. The front end of the catheter is a hard tube section, and when the hooking and pulling rod is located in the catheter, the elastic hooking and pulling section is limited to be in a straight state by the inner wall of the catheter; after the front end of the hook pull rod slides and extends out along the axial direction of the catheter, the elastic hook pull section is naturally bent into a hook state; the middle of the catheter is an adjustable bent pipe section, two stay wires are distributed in the catheter at intervals, one end of each stay wire is connected with the front end of the catheter, the other end of each stay wire extends to the outside of the catheter, and the bending degree of the middle of the catheter can be adjusted by applying different pulling forces to the two stay wires. The adjustable bending recovery hook can adapt to the complex blood vessel environment and can accurately grab the filter attached to the wall or with the abnormal posture.

Description

Technical Field

[0001] The present application belongs to the technical field of medical devices and relates to an intravascular adjustable bend retrieval hook for interventional surgery. Background Art

[0002] Deep vein thrombosis (DVT) and pulmonary embolism (PE) are common vascular obstructive diseases. Pulmonary embolism, the most serious complication of DVT, can cause sudden dyspnea, chest pain, and even sudden death, seriously endangering patients' lives. For high-risk patients who cannot tolerate long-term anticoagulation or who continue to develop PE during anticoagulation, implanting a vena cava filter in the inferior vena cava to intercept thrombi is a key approach to reducing the risk of PE.

[0003] However, while vena cava filters can provide a short-term solution to the risk of thromboembolism, their long-term indwelling can lead to numerous complications, including filter migration, fracture, perforation, inferior vena cava thrombosis or occlusion, and localized vascular stenosis. These complications not only impact patients' quality of life but can also lead to serious consequences such as secondary embolism or massive bleeding. Therefore, clinical guidelines generally recommend that vena cava filters be removed as soon as possible after the patient's thrombotic risk is reduced (e.g., acute DVT stabilization and anticoagulation therapy is effective) to minimize long-term complications and restore normal physiologic function of the inferior vena cava. Currently, vena cava filter removal has become a routine procedure in interventional radiology and endovascular surgery.

[0004] Despite the urgent clinical need for vena cava filter removal, the performance of existing retrieval devices is insufficient to meet the requirements of complex clinical scenarios. Currently, the mainstream filter retrieval device is primarily a snare, whose core structure is a rigid wire loop. Retrieval is accomplished by mechanically expanding the filter and then entrapping the filter with a hook or loop at the end. However, these devices have significant drawbacks. First, when the filter is displaced, adhered to the vessel wall, or wrapped by tissue, causing the hook (or loop) at the end of the filter to cling to the vessel wall, the rigid snare is difficult to adjust to the filter shape, significantly reducing the success rate of retrieval. Second, the snare's large size makes it prone to friction with the vessel wall during intravascular insertion, especially in tortuous vessels or when the filter is positioned abnormally (such as tilted or inverted). This increases forward resistance and may cause vascular damage. Third, traditional devices lack a flexible angle adjustment mechanism and are unable to adapt to the physiological curvature of the inferior vena cava and the complex spatial structure surrounding the filter. This makes the operation difficult and the procedure time lengthy. Repeated attempts may even lead to intimal damage or further displacement of the filter. The above problems directly lead to an increased failure rate of filter removal surgery and an increased risk of complications (such as vascular rupture and thrombosis), which seriously restricts the safety and effectiveness of the clinical application of vena cava filters. Therefore, improvements are urgently needed. Summary of the Invention

[0005] In response to the defects or improvement needs of the existing technology, the present application provides an intravascular adjustable curved retrieval hook for interventional surgery, which aims to improve the problem that the retrieval instrument is difficult to adapt to the complex vascular environment and difficult to accurately grasp the filter that is adhered to the wall or has abnormal posture.

[0006] The present application provides an intravascular adjustable bend retrieval hook for interventional surgery, comprising a catheter and a hook pull rod, wherein: The hook pull rod is slidably and adjustably arranged in the catheter, and the front end of the hook pull rod is an elastic hook pull section; The front end of the catheter is a hard tube section. When the hook pull rod is in the catheter, the elastic hook pull section is restricted by the inner wall of the catheter to a straight state. After the front end of the hook pull rod slides and extends along the axial direction of the catheter, the elastic hook pull section naturally bends into a hook state. The middle part of the catheter is an adjustable curved pipe section, and two pull wires are spaced apart inside the catheter. One end of each pull wire is connected to the front end of the catheter, and the other end extends to the outside of the catheter. By applying different pulling forces to the two pull wires, the degree of bending of the middle part of the catheter can be adjusted.

[0007] As a further preference, the elastic hook pull section is a flat rod, both ends of which in the width direction are respectively in contact with the inner wall of the catheter, and both ends of which in the thickness direction are respectively in clearance fit with the inner wall of the catheter.

[0008] As a further preferred embodiment, a protruding structure is provided inwardly of the port of the catheter, and both ends of the elastic hook section in the thickness direction are respectively fitted with the protruding structure.

[0009] As a further preference, the middle portion of the hook pull rod is a cylindrical section, and the end surface of the cylindrical section can form an interference limit with the protruding structure.

[0010] As a further preferred embodiment, the curved inner side of the hook pull rod is provided with a notch, and the open end surface of the conduit is provided with a limiting groove; When the hook rod slides along the axial direction of the catheter and extends to the opening of the catheter corresponding to the notch, a tip is formed at the transition between the inner wall of the notch and the wall of the hook rod to be embedded in the limiting groove.

[0011] As a further preferred embodiment, a notch is provided on the side wall of the hard tube section, and the cylindrical section of the hook pull rod is a flexible structure; After the cylindrical section and the protruding structure form an interference limit, pushing the hook rod can cause the cylindrical section to partially deform and protrude from the notch to form a protruding limit portion, which cooperates with the elastic hook section to limit the hooked object.

[0012] As a further preference, the diameter of the notch decreases from inside to outside along the wall thickness direction of the hard pipe section.

[0013] As a further preference, a plurality of tooth-shaped structures are provided at a portion of the curved inner side of the hook pull rod close to the notch, and a plurality of tooth grooves adapted to the tooth-shaped structures are provided at the open end surface of the conduit.

[0014] In general, the above technical solutions conceived by this application have the following technical advantages compared with the existing technologies: 1. The adjustable retrieval hook disclosed herein can be inserted into a blood vessel during surgery, allowing for the bending of the hook head and hook body to be adjusted. By flexibly adjusting the bending angle and direction of the hook based on the intravascular environment, it allows medical personnel to accurately retrieve and retrieve intravascular implants (such as inferior vena cava filters) that have dislocated, displaced, or adhered to the wall. This device is particularly suitable for retrieval of inferior vena cava filters in unusual positions, such as when the tail end is tilted or adhered to the wall.

[0015] 2. The front end of the adjustable retrieval hook of this application features an adjustable bend design, capable of hooking onto the mesh or tail ring of an intravascular implant device. The middle portion of the adjustable retrieval hook utilizes an adjustable tubular structure, enabling adjustment of the hook's overall bending angle and direction. During use, by pulling the pull wire at the tail of the adjustable retrieval hook and adjusting the hook pull rod by pushing and pulling, the adjustable retrieval hook can be bent in multiple positions, enabling precise positioning and effective retrieval. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic structural diagram of an adjustable bend recovery hook provided in an embodiment of the present application; Figure 2 is a cross-sectional view of an adjustable bend recovery hook provided in an embodiment of the present application; Figure 3 This is a diagram of the state of the adjustable bend recovery hook when the hook pull rod is slightly extended according to an embodiment of the present application; Figure 4 This is a diagram of the state of the adjustable bending recovery hook when the hook pull rod is greatly extended according to an embodiment of the present application; Figure 5 This is a partial enlarged view of the adjustable bend recovery hook provided in an embodiment of the present application; Figure 6 This is a layout diagram of the cylindrical section and the elastic hook section provided in an embodiment of the present application; Figure 7 This is another partially enlarged view of the adjustable bend recovery hook provided in an embodiment of the present application; Figure 8 Schematic diagram of the structure of the adjustable bending recovery hook with a notch provided in an embodiment of the present application; Figure 9 This is a schematic diagram of the use of an adjustable curved recovery hook with a notch provided in an embodiment of the present application; Figure 10 This is a schematic diagram of the bending state of the adjustable bending recovery hook provided in an embodiment of the present application.

[0017] Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein: 1. Catheter; 1-1. Hard pipe section; 1-2. Adjustable bend section; 1-3. Raised structure; 1-4. Limiting groove; 1-5. Tooth groove; 1-6. Notch; 1-7. First groove; 1-8. Second groove; 1-9. Guide sleeve; 2. Hook and pull rod; 2-1. Elastic hook and pull section; 2-2. Cylindrical section; 2-3. Missing corner; 2-4. Toothed structure; 2-5. Raised limiting part; 2-6. Tip; 3. Pull line; 4. Object to be hooked and pulled. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0019] The following is combined with Figures 1-10 This application is described in further detail.

[0020] The present application discloses an intravascular adjustable bend retrieval hook for interventional surgery. Figures 1-4 The intravascular adjustable bend retrieval hook includes a catheter 1 and a hook rod 2, wherein the hook rod 2 is slidably and adjustably arranged in the catheter 1, and the front end of the hook rod 2 is an elastic hook section 2-1; and the front end of the catheter 1 is a hard tube section 1-1. When the hook rod 2 is in the catheter 1, the front end of the hook rod 2 is restricted to a straight state by the inner wall of the catheter 1; after the front end of the hook rod 2 slides out along the axial direction of the catheter 1, the front end of the hook rod 2 naturally bends into a hook state; and the middle part of the catheter 1 is the adjustable bend tube section 1-2, and two pull wires 3 are spaced apart in the catheter 1, one end of the two pull wires 3 is connected to the front end of the catheter 1, and the other end extends to the outside of the catheter 1. By applying different pulling forces to the two pull wires 3, the bending degree of the middle part of the catheter 1 can be adjusted.

[0021] Further, such as Figure 2 As shown, in some embodiments, the elastic hook pull section 2-1 is a flat rod (usually made of memory metal), and its width direction (ie Figure 2 The two ends of the pipe 1 are respectively fitted with the inner wall of the pipe 1, and the thickness direction (ie Figure 2 The two ends of the elastic hook section 2-1 are respectively fitted with the inner wall of the catheter 1. When not limited by the catheter 1, the elastic hook section 2-1 can be Figure 3 As shown, the metal sheet is bent toward one side along its thickness direction to form a hook.

[0022] Generally speaking, the degree of bending of the elastic hook pull section 2-1 will change with the length of the elastic hook pull section 2-1 extending from the front end of the catheter 1. When the extended length is short, the hook pull rod 2 will bend to Figure 3 When the extended length is longer, the hook lever 2 will be further bent to present Figure 4 U-hook shown.

[0023] Further, such as Figure 5 As shown, in some embodiments, a protrusion structure 1-3 is provided inwardly from the front end of the catheter 1, and both ends of the elastic hook section 2-1 in the thickness direction are respectively in contact with the protrusion structure 1-3. The provision of the protrusion structure 1-3 can enhance the lateral restraining effect of the catheter 1 on the elastic hook section 2-1, ensuring that the elastic hook section 2-1 can be restrained by the inner wall of the catheter 1 in a substantially straight state.

[0024] Further, such as Figure 6 As shown, in some embodiments, the middle portion of the hook pull rod 2 is a cylindrical section 2-2, and the cylindrical section 2-2 can form a stepped surface with the flat elastic hook pull section 2-1, so that the end face of the cylindrical section 2-2 can form a conflict limit with the protruding structure 1-3. Under this design, through the conflict limit effect between the cylindrical section 2-2 and the protruding structure 1-3, the hook pull rod 2 in the adjustable bend recovery hook can be extended outward along the catheter 1 to a specified length, so that the final bend hook shape reaches a standard state. It should be noted that the stepped surface formed should be able to smoothly pass through the end port of the hard pipe section 1-1 away from the protruding structure 1-3, so as to ensure that the hook pull rod 2 can be smoothly stretched and adjusted without hindrance. Generally speaking, the stepped surface or the end port of the hard pipe section 1-1 away from the protruding structure 1-3 can be chamfered.

[0025] Further, refer to Figure 7 In some embodiments, the curved inner side of the hook rod 2 is provided with a notch 2-3, and the open end surface of the catheter 1 is provided with a limit groove 1-4. When the hook rod 2 slides axially along the catheter 1 and extends until the notch 2-3 corresponds to the opening of the catheter 1, the hook rod 2 bends toward the side where the notch 2-3 is located, forming a relatively sharp hook. A tip 2-6 is formed at the transition point between the inner wall of the notch 2-3 and the wall of the hook rod 2, which engages the limit groove 1-4. The geometric constraint and friction between the tip 2-6 and the limit groove 1-4 prevent the hook rod 2 from retreating axially. Furthermore, the design of the notch 2-3 allows the hook rod 2 to form a greater degree of curvature. Of course, in some embodiments, multiple notches 2-3 can be provided along the axial direction of the hook rod 2.

[0026] Furthermore, in some embodiments, the curved inner side of the hook lever 2 is provided with a plurality of tooth-shaped structures 2-4, distributed sequentially along the length of the hook lever 2. The open end surface of the catheter 1 is formed with a plurality of tooth grooves 1-5, the contours of which match the surfaces of the tooth-shaped structures 2-4. After the elastic hook section 2-1 of the hook lever 2 is bent toward the catheter 1 into a hook shape, the tooth-shaped structures 2-4 on the curved inner side can gradually and roughly fit into the tooth grooves 1-5, thereby enhancing the anti-backward capability of the hook lever 2.

[0027] Further, such as Figure 8-Figure 9 As shown, in some embodiments, the side wall of the hard tube section 1-1 is provided with a notch 1-6, and the cylindrical section 2-2 of the hook pull rod 2 is a flexible structure (such as a medical silicone rod); after the cylindrical section 2-2 and the protruding structure 1-3 form a conflicting limit, pushing the hook pull rod 2 can cause the cylindrical section 2-2 to partially deform and protrude out of the notch 1-6 to form Figure 9 The raised stopper 2-5 forms a lateral stop for the object 4 (only a partial cross-section of the object 4 is shown for ease of understanding) within the curved hook, thereby cooperating with the elastic hook section 2-1 to retain the object 4. With this design, the adjustable bend recovery hook is particularly suitable for hooking and pulling the filter tail, effectively contacting the side walls of the hook body at the filter tail, thereby improving the hooking stability of the filter tail.

[0028] As a preferred Figure 8 As shown, the diameter of the notch 1-6 decreases from the inside to the outside along the wall thickness of the hard pipe section 1-1. With this design, the resulting raised stopper is generally arc-shaped, which can guide the cylindrical section 2-2 of the hook pull rod 2 to produce a more uniform stress distribution during deformation, reducing the risk of deformation overload.

[0029] Furthermore, in some embodiments, the hook lever 2, except for the front end, is comprised of a flexible, bendable cylindrical section 2-2. During bending adjustment of the flexible section, the curved flexible section causes the hook lever 2 to deform accordingly, ensuring that the entire middle portion of the adjustable recovery hook can bend and adjust. Of course, in some embodiments, the rear end of the hook lever 2 can also be configured as a rigid, thin rod.

[0030] Further, such as Figure 1As shown, in some embodiments, two groups of grooves are spaced apart in the diameter direction in the middle of the catheter 1, and the two groups of grooves correspond one to one to the two pull wires 3. Each group of grooves includes a first groove 1-7 and a second groove 1-8 spaced apart in the axial direction, and a guide sleeve 1-9 is fixedly provided at the second groove 1-8, and the axial ends of the guide sleeve 1-9 are gap-matched with the inner wall of the second groove 1-8. The pull wire 3 is axially inserted into the guide sleeve 1-9, and one axial end of the pull wire 3 is connected to the hard pipe section 1-1 (usually by bonding), and the other axial end of the pull wire 3 extends through the catheter 1. Based on the groove design, by pulling the pull wire 3, the middle part of the catheter 1 can be deformed (such as Figure 10 as shown) to achieve the mid-bend of the adjustable bend retrieval hook.

[0031] Furthermore, in some embodiments, the tail of the hook pull rod 2 (i.e., the end away from the elastic hook pull section 2-1) is connected to a handle (not shown in the figure), and the handle is provided with an adjustment structure for pushing and pulling the hook pull rod 2 and stretching. The adjustment structure can adopt an existing structure and will not be elaborated here.

[0032] In summary, in this design, the front end of the adjustable bend retrieval hook adopts a bend hook design with adjustable bending degree, which can hook the grid or tail ring of the implant device. In addition, the middle part of the adjustable bend retrieval hook adopts an adjustable bend tubular structure, which can adjust the overall bending angle and direction of the retrieval hook. By stretching the pull wire 3 and pushing and pulling the hook pull rod 2 at the tail of the adjustable bend retrieval hook, the bending degree of the front end bend hook and the middle tube section can be adjusted, so that medical staff can flexibly control the multi-posture bending of the instrument according to the intraoperative vascular morphology and implant position, and achieve precise positioning and effective recovery.

[0033] When the hook is actually used, the end of the hook pull rod 2 is pulled and adjusted. The front end of the hook pull rod 2 can extend out of the front end of the catheter 1 under the pulling action to adaptively form a curved hook state. When the front end of the hook pull rod 2 is completely inside the catheter 1, the hook pull rod 2 will cling to the inner wall of the catheter 1. At this time, the catheter 1 and the hook pull rod 2 are as follows Figure 1 The slender column shape shown in the figure makes it easy for the device to extend and move forward in the blood vessel. When the hook pull rod 2 is extended from the catheter 1, the hook pull rod 2 will deform and return to the bent state; when the hook pull rod 2 is initially extended to a certain length, the extension length and deformation amplitude of the elastic hook pull section 2-1 are relatively small, and it is roughly Figure 3 The hook rod 2 can be used to hook the filter, or when the filter is adhered to the blood vessel membrane, the front end of the hook rod 2 can be used to tear the blood vessel membrane to separate the filter from the blood vessel. Continue to push the end of the hook rod 2 at the tail of the hook filter to make the hook rod 2 continue to extend forward. The front end of the hook rod 2 will continue to deform to form a Figure 4The U-shaped hook shown can be used to pull the mesh or tail ring of the filter through the U-shaped hook pull rod 2.

[0034] In some special cases, such as when the filter posture is not good (recovery is ectopic, adhered to the wall, etc.), medical staff can try to extend the hook rod 2 to hook other parts of the filter (such as extending the hook rod 2 to the required bending amplitude, and using the bent part of the hook rod 2 to hook and move the filter network on the filter, and try to adjust the filter posture to return to the normal position), so that the filter can be corrected, which is conducive to the removal of the filter.

[0035] Therefore, the adjustable bend retrieval hook of the present application can be used in blood vessels for interventional surgery, and can flexibly adjust the bending angle and direction within the blood vessel. At the same time, the bending of the hook head and the hook body can be adjusted, which is convenient for medical staff to accurately hook the intravascular implant device (such as the inferior vena cava filter) that has slipped, displaced or adhered to the wall, and realize the recovery of the intravascular implant device. In particular, it is suitable for the recovery of the inferior vena cava filter with a tilted tail end or adhered to the wall.

[0036] It should be understood that expressions such as "include" and "may include" used in this application indicate the existence of the disclosed functions, operations, or constituent elements, and do not limit one or more additional functions, operations, and constituent elements. In this application, terms such as "include" and / or "have" may be interpreted as indicating a specific characteristic, number, operation, constituent element, component, or combination thereof, but may not be interpreted as excluding the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components, or combinations thereof.

[0037] It should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0038] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0039] In this application, unless otherwise specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they can refer to fixed connection, detachable connection, or integral connection; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0040] It is easy for those skilled in the art to understand that the above is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. An intravascular adjustable bend retrieval hook for interventional surgery, characterized in that: It comprises a catheter (1) and a hook pull rod (2), wherein: The hook pull rod (2) is slidably and adjustably arranged in the catheter (1), and the front end of the hook pull rod (2) is an elastic hook pull section (2-1); The front end of the catheter (1) is a hard tube section (1-1); when the hook pull rod (2) is in the catheter (1), the elastic hook pull section (2-1) is restricted by the inner wall of the catheter (1) to be in a straight state; after the front end of the hook pull rod (2) slides out along the axial direction of the catheter (1), the elastic hook pull section (2-1) naturally bends into a hook state; The middle portion of the catheter (1) is an adjustable curved pipe section (1-2), and two pull wires (3) are spaced apart inside the catheter (1). One end of each pull wire (3) is connected to the front end of the catheter (1), and the other end extends to the outside of the catheter (1). By applying different pulling forces to the two pull wires (3), the degree of bending of the middle portion of the catheter (1) can be adjusted.

2. The adjustable bend recovery hook according to claim 1, characterized in that: The elastic hook pull section (2-1) is a flat rod, and its two ends in the width direction are respectively fitted with the inner wall of the catheter (1), and its two ends in the thickness direction are respectively fitted with the inner wall of the catheter (1) in a clearance.

3. The adjustable bend recovery hook according to claim 2, characterized in that: A protruding structure (1-3) is provided inwardly at the port of the catheter (1), and both ends of the elastic hook section (2-1) in the thickness direction are respectively fitted with the protruding structure (1-3).

4. The adjustable bend recovery hook according to claim 3, characterized in that: The middle portion of the hook pull rod (2) is a cylindrical section (2-2), and the end surface of the cylindrical section (2-2) can form a conflicting limit with the protruding structure (1-3).

5. The adjustable bend recovery hook according to claim 3, characterized in that: The curved inner side of the hook pull rod (2) is provided with a notch (2-3), and the open end surface of the conduit (1) is provided with a limiting groove (1-4); When the hook pull rod (2) slides and extends along the axial direction of the catheter (1) to the opening of the catheter (1) corresponding to the notch (2-3), a tip (2-6) is formed at the transition point where the inner wall of the notch (2-3) and the outer wall of the hook pull rod (2) are connected to be embedded in the limiting groove (1-4).

6. The adjustable bend recovery hook according to claim 3, characterized in that: The curved inner side of the hook pull rod (2) is provided with a plurality of tooth-shaped structures (2-4), and the open end surface of the catheter (1) is provided with a plurality of tooth grooves (1-5) adapted to the tooth-shaped structures (2-4).

7. The adjustable bend recovery hook according to claim 3, characterized in that: The side wall of the hard pipe section (1-1) is provided with a notch (1-6), and the cylindrical section (2-2) of the hook pull rod (2) is a flexible structure; After the cylindrical section (2-2) and the raised structure (1-3) form a conflicting limit, the hooking rod (2) is pushed, so that the cylindrical section (2-2) is partially deformed and protrudes out of the notch (1-6) to form a raised limit portion (2-5), so as to cooperate with the elastic hooking section (2-1) to limit the hooked object (4).

8. The adjustable bend recovery hook according to claim 7, characterized in that: The diameter of the notch (1-6) decreases from inside to outside along the wall thickness direction of the hard pipe section (1-1).

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