Self-locking device for short-range recovery of stents, stent and method for short-range recovery of stents

Abstract

The embodiment of the present application provides a self-locking device for short-range recovery of a stent, the stent and a short-range recovery method of the stent. The self-locking device comprises a shrink line and a self-locking piece, the shrink line comprises a center line and two tail lines; the self-locking piece comprises a shell and a containing cavity, an elastic body is arranged in the containing cavity, the center line penetrates into one end of the shell, penetrates through the elastic body and then penetrates out from the other end of the shell, the part of the center line penetrating out of the shell is provided with a recovery hook taking coil, and the containing cavity comprises a free section, a self-locking section and a transition section. In the self-locking device for short-range recovery of the stent, the cooperation between the shrink line and the self-locking piece can make the stent be stably self-locked in a specified diameter state without being expanded and unfolded. Specifically, due to the different pressures of the two ends of the containing cavity on the elastic body, the stent can be stably self-locked during the recovery process, and due to the movement of the two tail lines at the same time, the shrinkage of the stent is realized, the recovery force is reduced, the required stroke of the self-locking of the stent is short, and the clinical operation is more friendly.

Description

Technical Field

[0001] This invention relates to the field of medical devices, and more specifically, to a self-locking device for short-range stent retrieval, a stent, and a method for short-range stent retrieval. Background Technology

[0002] Retrieval of complex stent structures remains a challenging problem in the current technological field. Stents with rivet-like structures, in particular, present significant difficulties during retrieval, and the longer the retrieval journey, the more complex the design of the retrieval equipment becomes. To address this issue, a retrieval line and its self-locking mechanism are typically required. However, existing technologies are complex, have poor reliability, and cannot meet engineering requirements.

[0003] Specifically, existing retrieval brackets with rivet structures often require complex retrieval lines and locking functions during the retrieval process. Implementing these lines and functions necessitates intricate engineering design and manufacturing processes, leading to increased production costs and decreased reliability. Furthermore, the complexity of these retrieval lines and locking functions makes them prone to malfunctions during actual use, further impacting project efficiency and safety. Additionally, even if some retrieval lines and their self-locking structures possess a certain degree of stability, the long stroke and large retrieval force required for the retrieval bracket's self-locking also cause inconvenience during retrieval.

[0004] In view of this, the present invention provides the following technical solution. Summary of the Invention

[0005] The present invention aims to provide, for example, a self-locking device for short-range retrieval of a stent, a stent, and a short-range retrieval method for the stent, which has a simple structure, high reliability, short stroke required for stent self-locking, and low retrieval force.

[0006] The embodiments of the present invention can be implemented as follows:

[0007] In a first aspect, the present invention provides a self-locking device for short-range retrieval of a support, comprising a retraction line and a self-locking component, wherein the retraction line comprises a center line and two tail lines disposed at both ends of the center line for winding around the support body to be retrieved.

[0008] The self-locking component includes a housing and a receiving cavity located within the housing. An elastomer is disposed within the receiving cavity. The centerline enters from one end of the housing, passes through the elastomer, and exits from the other end of the housing. A retrieval hook coil is disposed at the portion of the centerline that exits the housing. A free section of the retractable wire that can move relative to the elastomer is disposed at the end of the receiving cavity near the retrieval hook coil. A self-locking section that the retractable wire cannot move relative to the elastomer is disposed at the end of the receiving cavity away from the retrieval hook coil. A transition section is disposed between the free section and the self-locking section. The cross-sectional area of ​​the transition section gradually increases along the direction closer to the retrieval hook coil.

[0009] In an optional embodiment, the self-locking component includes a first housing and a second housing that are fixedly or detachably connected to each other, the first housing and the second housing forming a conical or frustum-shaped receiving cavity, and the centerline passing through the self-locking component from its axis.

[0010] In an optional embodiment, the elastic body is at least one of a sphere, a cone, and a frustum.

[0011] And / or, the material of the elastomer is silicone.

[0012] In an optional embodiment, the receiving cavity is a cone, the elastic body is a sphere, and the angle between the generatrix of the receiving cavity and the axis is 10°-30°.

[0013] In an optional embodiment, the portion of the centerline extending out of the housing is made into a double-strand single knot to form the recovery hook coil.

[0014] In an optional implementation, the two tail wires are of equal length.

[0015] Secondly, the present invention provides a bracket, including a bracket body and a self-locking device as described in any of the foregoing embodiments, wherein two tail wires of the self-locking device are wound around the bracket body to form a retractable loop, and both ends of the retractable wires are fixed on the bracket body.

[0016] In an optional embodiment, the support body includes a wave-shaped frame with fixing spikes on the outer side of the frame.

[0017] In an optional embodiment, the shrink ring is provided 1-2 times around the support body;

[0018] And / or, the recovery hook coil is located inside the support body.

[0019] Thirdly, the present invention provides a short-range retrieval method for the stent described in any of the foregoing embodiments, comprising: using a retrieval hook to hook the retrieval hook coil, with an end cap located outside the retrieval hook abutting against the self-locking member; then pulling the retrieval hook to retract the stent body; then removing the tension applied by the retrieval hook to stabilize the stent body to a specified retracted state before retrieval, wherein the tension used when pulling the retrieval hook to retract the stent body satisfies F. 收 >F 摩擦 +F 弹 When the support body stabilizes to a specified contraction state, it satisfies F. 摩擦 >F 弹 F 摩擦 F is the frictional force between the contraction line and the elastomer. 弹 The elastic force that needs to be overcome for the contraction of the stent body.

[0020] The beneficial effects of the embodiments of the present invention include, for example:

[0021] In the self-locking device for short-range stent retrieval in this embodiment of the invention, the cooperation between the contraction line and the self-locking component allows the stent to stably lock at a specified diameter without expanding or unfolding. Specifically, due to the different pressures on the elastic element at both ends of the receiving cavity, the stent achieves stable self-locking during retrieval. Simultaneously, the stent contracts as both tail lines move, reducing the retrieval force and shortening the stroke required for stent self-locking, making it more user-friendly for clinical operations. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 A schematic diagram of a support structure with a self-locking device for short-range retrieval of the support.

[0024] Figure 2 This is a schematic diagram of the self-locking component;

[0025] Figure 3 A schematic diagram of a stent in its retracted state, featuring a self-locking device for short-range stent retrieval.

[0026] Figure 4 This is a schematic diagram of the support structure used in Experiment Example 2.

[0027] Icons: 100 - Shrink line; 110 - Center line; 111 - Recovering hook coil; 112 - Double strand single knot; 120 - Tail line; 121 - Single section; 200 - Self-locking component; 210 - Housing; 220 - Receiving cavity; 221 - Free section; 222 - Self-locking section; 223 - Transition section; 230 - Elastomer; 300 - Support body; 310 - Fixing spike; 400 - Recovering hook; 500 - End cap; 600 - Self-locking coil assembly. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0029] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0030] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0031] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed, they are only for the convenience of describing this 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, and therefore should not be construed as a limitation of this invention.

[0032] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0033] It should be noted that, where there is no conflict, the features in the embodiments of the present invention can be combined with each other.

[0034] Please refer to Figure 1-3This embodiment provides a self-locking device for short-range retrieval of a support, including a retraction line 100 and a self-locking component 200. The retraction line 100 includes a center line 110 and two tail lines 120 disposed at both ends of the center line 110 for winding around the support body to be retrieved.

[0035] The self-locking component 200 includes a housing 210 and a receiving cavity 220 located within the housing 210. An elastic body 230 is disposed within the receiving cavity 220. The centerline 110 enters from one end of the housing 210, passes through the elastic body 230, and exits from the other end of the housing 210. A retrieval hook coil 111 is disposed on the portion of the centerline 110 that exits the housing 210. A free segment 221, in which a retraction line 100 can move relative to the elastic body 230, is disposed at the end of the receiving cavity 220 near the retrieval hook coil 111. A self-locking segment 222, in which the retraction line 100 cannot move relative to the elastic body 230, is disposed at the end of the receiving cavity 220 away from the retrieval hook coil 111. A transition segment 223 is disposed between the free segment 221 and the self-locking segment 222. The cross-sectional area of ​​the transition segment 223 gradually increases along the direction closer to the retrieval hook coil 111.

[0036] The self-locking device for short-range retrieval of the support in this embodiment of the invention includes a retraction line 100 for retracting the housing 210 and a self-locking member 200 for self-locking the retraction line 100. The structure of the self-locking member 200 is as follows: Figure 2 As shown, the retraction line 100 passes through the self-locking member 200. Within the self-locking member 200, when the retrieval hook coil 111 is pulled, the friction between the retraction line 100 and the elastic body 230 causes the elastic body 230 to move closer to the retrieval hook coil 111. At this time, the elastic body 230 is located in the free section 221, and the cross-sectional area of ​​the elastic body 230 is smaller than or slightly larger than the cross-sectional area of ​​the free section 221. The inner wall does not apply pressure to the elastic body 230 or applies only a small pressure. Under the pull of the retrieval hook 400, the retraction line 100 gradually passes through the self-locking member 200. This causes the length of the shrinkage line 100 wound around the bracket to gradually decrease, thereby achieving the purpose of causing the shrinkage line 100 to shrink. When the bracket shrinks to a specified degree, the retraction hook 400 is released, and the bracket will expand under its own elastic force. At this time, the portion of the shrinkage line 100 wound around the bracket gradually lengthens, and the shrinkage line 100 in the elastic body 230 moves away from the free section 221. At the same time, under the action of friction, the elastic body 230 gradually moves to the self-locking section 222, realizing the self-locking of the bracket. The structural diagram of the bracket in the self-locking state is shown below. Figure 3 As shown.

[0037] It should be noted that the contraction line 100 in this embodiment is a continuous line. The midline 110 and the tail line 120 are only for the convenience of segmenting the various parts of the contraction line 100. The material can be a flexible line that meets the implantation requirements, such as HDPE. The tail line 120 of the contraction line 100 can be wrapped around the stent. In this application, the stent includes, but is not limited to, gastric bypass stents, dense mesh esophageal stents, etc.

[0038] In this application, the self-locking device only needs to satisfy the condition that the frictional force on the contraction line 100 is greater than the elastic force required for the support to recover its deformation when the elastic body is in the self-locking section 222 to achieve self-locking.

[0039] In the self-locking device for short-range stent retrieval in this embodiment of the invention, the cooperation between the contraction line 100 and the self-locking component 200 allows the stent to stably self-lock at a specified diameter without expanding or unfolding. Specifically, due to the different pressures on the elastic element at both ends of the receiving cavity 220, the stent achieves stable self-locking during retrieval. Simultaneously, the two tail lines 120 move simultaneously to achieve stent contraction, reducing the retrieval force and shortening the stroke required for stent self-locking, making it more user-friendly for clinical operations.

[0040] In an optional embodiment, the self-locking member 200 includes a first housing 210 and a second housing 210 that are fixed or detachably connected to each other. The first housing 210 and the second housing 210 form a conical or frustoconical receiving cavity 220. The centerline 110 passes through the self-locking member 200 from the axis of the self-locking member 200.

[0041] In this embodiment, the housing 210 of the self-locking component 200 consists of two parts. During assembly, the elastic element can be placed inside the first housing 210 or the second housing 210 first, and then the first and second housings 210 are fixed to complete the assembly of the self-locking component 200. The first and second housings 210 can be made of metal or rigid plastic, and the fixing method between them can be conventional methods such as bonding or snap-fitting. The elastic element can be made of materials such as silicone that meet implantation requirements and have a certain degree of elasticity.

[0042] In an optional embodiment, the elastomer 230 is made of silicone.

[0043] Specifically, in this embodiment, the self-locking component 200 is provided with through holes on the first housing 210, the second housing 210, and the elastic component for the middle of the shrink line 100 to pass through. It should be noted that, in order to appropriately increase the friction between the shrink line 100 and the elastic component, the through hole can be pre-set on the housing 210 and the elastic component, or when the shrink line 100 is inserted, a thinner needle or hook (with a diameter smaller than the shrink line 100) can be used to directly guide the shrink line 100 through the housing 210 and the elastic component, forming a through hole at the same time as threading. In this way, the shrink line 100 and the elastic component can make fuller contact, which is beneficial to the full contact between the shrink line 100 and the elastic component, thereby improving the friction between the two, reducing the diameter of the bracket when self-locking, and improving the self-locking capability.

[0044] In an optional embodiment, the elastic body 230 is at least one of a sphere, a cone, and a frustum.

[0045] As for the shape of the elastomer 230, as long as it can cooperate with the receiving cavity 220 so that the elastomer 230 can be fully subjected to the pressure applied by the inner wall of the receiving cavity 220 in the transition section 223 and the self-locking section 222, and then transfer the pressure to the telescopic line to achieve the self-locking of the self-locking member 200.

[0046] In an optional embodiment, the receiving cavity 220 is a cone, the elastic body 230 is a sphere, and the angle between the generatrix of the receiving cavity 220 and the axis is 10°-30°.

[0047] The larger the angle (i.e., taper) between the generatrix of the receiving cavity 220 and the axis, the smaller the size of the self-locking component 200 will be. However, if the angle between the generatrix of the receiving cavity 220 and the axis is too large, the length of the transition section 223 will be too short. If the force applied by the recovery hook 400 to the recovery hook coil 111 during recovery is unstable, the elastic body 230 may enter the self-locking section 222 from the free section 221, resulting in an excessively large diameter of the bracket during self-locking. Therefore, the angle between the generatrix of the receiving cavity 220 and the axis, i.e., the rate of change of the cross-sectional area of ​​the receiving cavity 220, should be appropriate.

[0048] In an optional embodiment, the portion of the centerline 110 that extends out of the housing 210 is made into a double-strand single knot 112 to form the recovery hook coil 111.

[0049] In some embodiments, although an additional hook loop can be provided at the portion of the centerline 110 that extends beyond the housing 210, this would increase cost and assembly difficulty. Therefore, in this embodiment, a double-strand single knot 112 is fabricated to form the recovery hook coil 111, which facilitates processing and reduces costs. In an optional embodiment, the two tail lines 120 are of equal length.

[0050] The two tail wires 120 are of equal length, which makes the winding structure of the shrink wire 100 symmetrical. This makes the symmetry of the two tail wires 120 moving in both directions during retrieval better, and makes the shrinkage force on each position of the support relatively balanced.

[0051] It should be noted that if an additional hook ring is provided on the part of the center line 110 that extends out of the housing 210, then if the lengths of the two tail lines are not equal, the force on the two tail lines will be uneven during the contraction of the bracket. In this case, the hook ring will move relative to the contraction line, so that the lengths of the two tail lines will become nearly equal, thereby making the bracket body contract relatively evenly. However, it should be noted that since the hook ring is thin and the space it occupies is small, if the hook ring and the contraction line move relative to each other, the friction force on the contraction line will be large and it may break. Therefore, using a hook ring and making a double-strand single knot 112 each have their advantages and disadvantages.

[0052] This embodiment also provides a bracket, including a bracket body 300 and a self-locking device as described in any of the preceding embodiments. The two tail wires 120 of the self-locking device are wound around the bracket body 300 to form a retractable loop, and both ends of the retractable wire are fixed on the bracket body 300.

[0053] In this embodiment, the two tail wires 120 of the self-locking device are wound around the bracket body 300 to form a shrinkage loop. When the lengths of the two tail wires 120 are equal, the shrinkage loop formed by the two tail wires 120 is also symmetrically arranged about one diameter of the bracket. The two ends of the shrinkage wire 100 can be single sections 121 or other wire section structures that can fix the ends of the shrinkage wire 100 to the bracket. In some embodiments, additional connection structures can also be used to fix the two ends of the shrinkage wire 100 to the bracket body 300.

[0054] In an optional embodiment, the support body 300 includes a wave-shaped frame, and a fixing spike 310 is provided on the outer side of the frame.

[0055] It should be noted that when the support structure is as described, the shrinkage line 100 can be directly threaded around the support. Figure 1 As shown, when the support structure is otherwise inconvenient to fix the shrinkage line 100, the shrinkage line 100 can also be threaded around the membrane tube sleeved on the support.

[0056] In an optional embodiment, the shrink ring is arranged 1-2 times around the support body 300. It should be noted that when the shrink ring is less than one turn around the support body 300, the support not covered by the shrink ring will be stretched when the recovery hook 400 pulls to retrieve the coil, which is not conducive to the uniform shrinkage of the support. However, if the number of shrink rings is too large, the stroke required for the support to self-lock will increase. Therefore, the number of shrink rings around the support body 300 should not be too many or too few; preferably, the shrink ring is arranged 1-1.2 times around the support body 300. Figure 1 As shown.

[0057] In an optional embodiment, the retrieval hook coil 111 is located inside the support body 300. When the retrieval hook 400 pulls the retrieval hook coil 111 to move the support, it is easier to maintain the balance of the support.

[0058] This embodiment also provides a short-range retrieval method for the stent described in any of the foregoing embodiments, comprising: using a retrieval hook 400 to hook the retrieval hook coil 111, with the end cap 500 located outside the retrieval hook 400 abutting against the self-locking member 200; then pulling the retrieval hook 400 to retract the stent body; then removing the tension applied by the retrieval hook to stabilize the stent body to a specified retracted state before retrieval; wherein the tension used to pull the retrieval hook 400 to retract the stent body satisfies F. 收 >F 摩擦 +F 弹 When the support body stabilizes to a specified contraction state, it satisfies F. 摩擦 >F 弹 F 摩擦 F is the frictional force between the contraction line 100 and the elastic body 230. 弹 The elastic force that needs to be overcome for the contraction of the stent body.

[0059] In this embodiment, when the pulling force applied by the retrieval hook 400 to the retrieval hook coil is greater than the sum of the frictional force between the retraction line 100 and the elastic body 230 and the elastic force that the support needs to overcome to retract, the support can be retracted, and the retrieval of the support can continue after the support is retracted.

[0060] First Experimental Example

[0061] This embodiment provides a Figure 1The short-range retrieval method for the stent includes: using a retrieval hook 400 to hook the retrieval hook coil 111, with the end cap 500 located outside the retrieval hook 400 abutting against the self-locking member 200; then pulling the retrieval hook 400 to retract the stent body; subsequently, removing the tension applied by the retrieval hook to stabilize the stent body to a specified retracted state before retrieval, wherein the tension used to pull the retrieval hook 400 to retract the stent body satisfies Fretrieval > Fretract. 摩擦 +F 弹 When the support body stabilizes to a specified contraction state, it satisfies F. 摩擦 >F 弹 F 摩擦 F is the frictional force between the contraction line 100 and the elastic body 230. 弹 The elastic force that the support needs to overcome during contraction is represented by a silicone ball, and the receiving cavity 220 is shaped like a frustum of a cone. Figure 1 Some parameters of the bracket are shown in Table 1, wherein F is adjusted by modifying the inner diameter of the preset through hole of the elastic element and the taper of the receiving cavity. 摩擦 Size.

[0062]

[0063]

[0064] Remark:

[0065] 1. The inner diameter of the pre-set through hole of the elastic element “\” means that there is no pre-set through hole on the elastic element, and the shrinkage line 100 is directly inserted into it later using a needle that is thinner than the shrinkage line 100.

[0066] 2. Required stroke for bracket self-locking: During the bracket retrieval process, the length by which the retrieval hook moves backward from its natural state to when the bracket is compressed to its minimum diameter. The measuring tool is a ruler.

[0067] 3. Average recovery force: Using the recovery hook 400, pull the recovery hook to the coil 111 until the bracket is compressed to the minimum diameter. Let the initial diameter of the bracket be a, and the minimum compressed diameter be b. Record the tensile force curve during this process using a tensile testing machine. Take the tensile force value when the bracket diameter decreases by (ab) / 2 as the average recovery force.

[0068] 4. Self-locking diameter: After the stent is compressed to its minimum diameter, release the retrieval hook 400, and the stent will expand and rebound. When the rebound force of the stent is balanced with the self-locking force, it reaches a stable state. At this time, measure the diameter of the root of the stent body, which is the self-locking diameter.

[0069] 5. If, during the retrieval process, the external tension is removed, the support can maintain a stable, balanced, and static state under a certain contraction state (i.e., the support diameter is smaller than its diameter when no external force is applied), this can be defined as self-locking. At this point, F can be achieved. 摩擦 Greater than F 弹 .

[0070] Second Experimental Example

[0071] This embodiment provides a Figure 4 The short-range retrieval method for the stent includes: using a retrieval hook 400 to hook the retrieval hook coil 111; the end cap 500 located outside the retrieval hook 400 abuts against the self-locking coil assembly 600; then pulling the retrieval hook 400 to retract the stent body; then removing the tension applied by the retrieval hook to stabilize the stent body to a specified retracted state before retrieval; wherein the tension used to pull the retrieval hook 400 to retract the stent body satisfies F1. 收 >F1 摩擦 +F1 弹 When the support body stabilizes to a specified contraction state, it satisfies F. 摩擦 >F 弹 F1 摩擦 F1 is the frictional force between the shrinkage wire 100 and the self-locking coil assembly 600. 弹 This refers to the elastic force that the stent needs to overcome during contraction. The stent body specifications and materials, as well as the contraction line specifications and materials, are the same as those used in the first experimental example. Figure 4 The bracket and Figure 1 The only difference in the bracket shown is that the self-locking component 200 is replaced with a self-locking coil assembly 600 (where a take-back hook coil 111 is provided at one end of the retraction wire 100, and then a take-back loop is formed around the bracket body 300, which is then wound around the retraction wire 100 near the take-back hook coil 111 to form a self-locking coil assembly 600, and the other end is fixed to the bracket body 300). Some parameters of the bracket are shown in Table 2, wherein F is adjusted by adjusting the number of turns of the self-locking coil assembly. 摩擦 Size.

[0072]

[0073] Remark:

[0074] 1. Required stroke for bracket self-locking: During the bracket retrieval process, the length by which the retrieval hook moves backward from its natural state to when the bracket is compressed to its minimum diameter. The measuring tool is a ruler.

[0075] 2. Average recovery force: Using the recovery hook 400, pull the recovery hook to take the coil 111 until the bracket is compressed to the minimum diameter. Let the initial diameter of the bracket be a, and the minimum compressed diameter be b. Record the tensile force curve during this process using a tensile testing machine. Take the tensile force value when the bracket diameter decreases by (ab) / 2 as the average recovery force.

[0076] 3. Self-locking diameter: After the stent is compressed to its minimum diameter, release the retrieval hook 400, and the stent will expand and rebound. When the rebound force of the stent is balanced with the self-locking force, it reaches a stable state. At this time, measure the diameter of the root of the stent body, which is the self-locking diameter.

[0077] 4. If, during the retrieval process, the external tension is removed, the support can maintain a stable, balanced, and static state under a certain contraction state (i.e., the support diameter is smaller than its diameter when no external force is applied), this can be defined as self-locking, i.e., F. 摩擦 Greater than F 弹 .

[0078] A comparison of Examples 1-5 with Comparative Examples 5-7 shows that, compared with the stent in this application, the retrieval force and the stroke required for stent self-locking can be effectively reduced, and the force on the stent is more balanced when the contraction line 100 contracts, which is more user-friendly for clinical operation.

[0079] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A stent, characterized by, The self-locking device comprises a shrinkable line and a self-locking part. The self-locking part comprises a housing and a receiving cavity in the housing, and an elastic body is arranged in the receiving cavity. The middle part of the middle line penetrates into the housing from one end of the housing, penetrates through the elastic body, and then penetrates out from the other end of the housing. The part of the middle line penetrating out of the housing is provided with a recovery hook taking coil.

2. The stent of claim 1, wherein The end of the receiving cavity close to the recovery hook taking coil is provided with a free section of the shrinkable line capable of moving relative to the elastic body.

3. The stent of claim 1, wherein The end of the receiving cavity away from the recovery hook taking coil is provided with a self-locking section of the shrinkable line incapable of moving relative to the elastic body. The free section and the self-locking section are provided with a transition section therebetween.

4. The stent of claim 1, wherein The cross-sectional area of the transition section gradually increases along the direction close to the recovery hook taking coil.

5. The stent defined in Claim 1, wherein, The two tail lines of the self-locking device are wound around the stent body to form a shrinkable ring, and the two ends of the shrinkable line are fixed on the stent body.

6. The stent defined in Claim 1, wherein, The self-locking part comprises a first housing and a second housing fixed or detachably connected with each other.

7. The stent defined in Claim 1, wherein, The first housing and the second housing enclose a conical or frustoconical receiving cavity, and the middle line penetrates through the self-locking part from the axis of the self-locking part.

8. The stent defined in Claim 1, wherein, The elastic body is at least one of a sphere, a cone, and a frustum. The material of the elastic body is silica gel. The receiving cavity is a cone, the elastic body is a sphere, and the included angle between the generatrix of the receiving cavity and the axis is 10°-30°. The part of the middle line penetrating out of the housing is made into a double-stranded single knot to form the recovery hook taking coil. The lengths of the two tail lines are equal. The stent body comprises a wave-shaped frame, and the outer side of the frame is provided with a fixing thorn. The shrinkable ring is arranged around the stent body for 1-2 turns. The recovery hook taking coil is located inside the stent body.

Images