Recyclable vascular stent

Abstract

The application provides a recyclable vascular stent, and belongs to the technical field of interventional treatment instruments; the stent comprises a first stent, a second stent and a separation component; the outer side wall of the first stent is used for directly supporting a blood vessel and can automatically contract in a radial direction; the second stent is coaxially arranged on the inner side of the first stent and is used for supporting the first stent to expand in a radial direction; the separation component is arranged on the first stent and / or the second stent and is used for reducing the friction between the first stent and the second stent; when the stent is taken out, the second stent is gradually taken out from the inner side of the first stent, and the first stent automatically contracts in a radial direction in the process of losing the support of the second stent to reduce the embedding force with the side wall of the blood vessel, so that the taking out of the whole stent is facilitated; and the technical problem that the existing technology has a large resistance and is not easy to take out when the vascular stent is taken out is solved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of interventional treatment instruments, and particularly relates to a retrievable vascular stent. BACKGROUND

[0002] The implantation scene of a vascular stent can be divided into a regular therapeutic scene (for example, treating vascular stenosis or solving the problem of ischemia caused by vascular occlusion, and protecting organ function) and a functional expansion scene (for example, collecting high-quality brain electrical signals by implanting a stent carrying electrodes in a cerebral blood vessel, assisting in the diagnosis of neurological diseases, long-term monitoring or optimizing treatment), and the core purpose is to improve the function of blood vessels by a minimally invasive method or to realize precision medicine by using a blood vessel passage.

[0003] No matter which therapeutic scene the vascular stent is in, when serious complications occur in stent implantation, the stent is allergic, the foreign body reaction is severe, or the electrode function on the stent fails and cannot complete the monitoring task, the stent needs to be removed from the blood vessel in time.

[0004] However, the stent usually needs to be expanded to adhere to the blood vessel wall after implantation. Because the blood vessel wall has elasticity, when the stent with a metal skeleton structure extrudes the blood vessel, it will sink into or embed in the plaque or stenotic tissue in the blood vessel, forming a mechanical "anchoring". For severe calcified vascular stenosis, the stent will extrude the calcified plaque when expanded, and part of the hard calcified tissue may be embedded in the stent grid, further enhancing the embedding force of the two. In this way, when the stent is axially pulled, the stent and the blood vessel generate a large friction force, especially at the curved part, the friction force between the stent and the blood vessel wall will further increase due to the angle relationship, resulting in a very large axial pulling resistance, and it is extremely difficult to remove the stent.

[0005] Therefore, it is necessary to provide an improved technical solution for the above-mentioned deficiencies of the prior art. SUMMARY

[0006] The purpose of the present application is to provide a retrievable vascular stent to solve the technical problems of large resistance and difficulty in removing the vascular stent in the prior art.

[0007] In order to achieve the above-mentioned purpose, the retrievable vascular stent of the present application provides the following technical solution:

[0008] A retrievable vascular stent, comprising:

[0009] A first stent, the outer side wall of the first stent is used to directly support the blood vessel, and can automatically contract radially;

[0010] A second stent, the second stent is coaxially arranged inside the first stent, and is used to support the radial expansion of the first stent;

[0011] An isolation component is arranged on the first stent and / or the second stent to reduce the friction between the first stent and the second stent.

[0012] When the stent is taken out, the second stent is gradually taken out from the inside of the first stent, and the first stent automatically shrinks radially during the process of losing the support of the second stent to reduce the embedding force with the sidewall of the blood vessel, facilitating the completion of the taking out of the whole stent.

[0013] As a further optimized technical solution, the isolation component includes a first isolation film and a second isolation film, the first isolation film is fixedly arranged on the inner sidewall of the first stent, and the second isolation film is fixedly arranged on the outer sidewall of the second stent.

[0014] As a further optimized technical solution, the recyclable vascular stent further includes a connecting unit for connecting the first stent and the second stent, for maintaining the integrity of the first stent and the second stent during the taking out of the second stent.

[0015] As a further optimized technical solution, the connecting unit includes a stop component and a hook-shaped component hung on the stop component, one of which is arranged on the first stent and the other is arranged on the second stent.

[0016] As a further optimized technical solution, the stop component is arranged at the proximal end of the inner sidewall of the first stent, and a plurality of hook-shaped components are arranged at the distal end of the second stent in a circumferential direction.

[0017] As a further optimized technical solution, the hook-shaped component includes a connecting rod and a protrusion arranged at the distal end of the connecting rod, and the protrusion and the connecting rod form a hook-shaped structure.

[0018] As a further optimized technical solution, the connecting rod is arranged obliquely, and the connecting rod gradually approaches the axis of the second stent from the end close to the second stent to the end away from the second stent, and the distance between the outer sidewall of all protrusions and the axis of the second stent is the same as the radius of the second stent.

[0019] As a further optimized technical solution, the stop component is a rope-shaped stop ring arranged on the first stent.

[0020] As a further optimized technical solution, the proximal end of the second stent is provided with a tensioning component for tensioning the second stent.

[0021] As a further optimized technical solution, the two ends of the tensioning component are respectively movably connected with two positions radially opposite to each other of the second stent, and the middle part of the tensioning component is provided with an engaging component matched with an external taking-out device.

[0022] Beneficial effects: The recyclable vascular stent of the present application is provided with a first stent capable of automatic radial contraction and a second stent for supporting the first stent. The first stent is mainly used for supporting the blood vessel, and the second stent does not directly contact the blood vessel, but is mainly used for making the first stent radially expand to meet the requirement of the first stent supporting the blood vessel. In this way, when the stent is taken out, the second stent is gradually taken out from the first stent, and the first stent automatically contracts radially after losing support, which can effectively reduce the embedding force with the side wall of the blood vessel, fundamentally reduce the resistance when the stent is taken out in the axial dragging manner in the prior art, and make the taking-out process more labor-saving and efficient. At the same time, the setting of the isolation component reduces the friction between the first stent and the second stent, so that the second stent is taken out more smoothly, avoids jamming due to excessive friction between the two, and further improves the smoothness of the operation.

[0023] Further, the design of the connecting unit not only ensures the integrity of the first stent and the second stent during the taking-out process of the second stent, but also avoids the danger of leaving the first stent alone in the blood vessel, and the cooperation mode of the hook-shaped component and the stop component enhances the reliability and adaptability of the structure, which can cope with different blood vessel environments and taking-out requirements.

[0024] Further, the setting of the tensioning component and the engaging component facilitates cooperation with external taking-out equipment, and thus the entire vascular stent can be smoothly taken out, greatly improving the safety and convenience of the vascular stent taking-out. In addition, the contraction of the first stent during the taking-out process can minimize the pulling and damage to the blood vessel wall, reducing the risk of complications such as blood vessel rupture and bleeding during the taking-out process, and providing good protection for the blood vessel.

[0025] The design of the recyclable vascular stent of the present application also expands the application range. Whether it is a complication that needs to be taken out in a conventional vascular stenosis treatment scenario, or a functional expansion scenario where the equipment fails and needs to be replaced, the operation can be efficiently and safely completed, providing a more flexible and reliable choice for clinical treatment, and having high clinical application value and promotion prospect. BRIEF DESCRIPTION OF DRAWINGS

[0026] The drawings accompanying the specification of this application serve to provide a further understanding of the present application, the illustrative embodiments of the present application and their descriptions serve to explain the present application, and do not constitute an improper limitation on the present application. Among them:

[0027] Figure 1 is a schematic view of the overall structure of an embodiment of the recyclable vascular stent of the present application;

[0028] Figure 2 is Figure 1 is a schematic view of the overall structure of an embodiment of the recyclable vascular stent of the present application;

[0029] Figure 3Second stent exploded view of one embodiment of the application;

[0030] Figure 4 First stent exploded view of one embodiment of the application;

[0031] Figure 5 Extraction view of one state of the second stent of one embodiment of the application;

[0032] Figure 6 Extraction view of another state of the second stent of one embodiment of the application;

[0033] In the figure: 100, first stent; 110, first isolation film; 120, stop component; 200, second stent; 210, second isolation film; 220, hook component; 221, connecting rod; 222, protruding block; 230, tension component; 240, joint component; 300, recovery sheath; 400, pulling wire. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the application will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art belong to the protection scope of the application.

[0035] In the description of the application, the orientations or positional relationships indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", and the like are based on the orientations or positional relationships shown in the drawings, and are only for the purpose of facilitating the description of the application and not for the purpose of requiring the application to be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application. The terms "connected", "connected" used in the application should be understood broadly, for example, can be fixed connection, can also be detachable connection; can be directly connected, can also be indirectly connected through intermediate components, and those skilled in the art can understand the specific meanings of the above terms according to the specific circumstances. In addition, the term "proximal end" refers to the end close to the operator, and the term "distal end" refers to the end away from the operator.

[0036] The application will be described in detail below with reference to the drawings and in combination with the embodiments. It should be noted that the embodiments in the application and the features in the embodiments can be combined with each other without conflict.

[0037] The shapes and sizes of the components in the drawings do not reflect the true proportions of the product, but only serve to illustrate the content of the application.

[0038] The application provides a retrievable vascular stent, which comprises a first stent 100, a second stent 200, an isolation component, a connecting unit and a tensioning component 230. The first stent 100 is made of a material with shape memory characteristics and automatically shrinks radially in normal state; the second stent 200 is coaxially arranged inside the first stent 100 and provides support for the first stent 100; the isolation component reduces the friction between the two; the connecting unit ensures the integrity of the two during removal; and the tensioning component facilitates the cooperation with external equipment to remove the second stent 200. During removal, the second stent 200 is extracted, and the first stent 100 gradually shrinks to reduce the embedding force with the sidewall of the blood vessel, so that the removal is convenient. The application effectively solves the problem of large removal resistance of the existing vascular stent, improves the safety and efficiency of removal, is suitable for various treatment scenes and has high clinical application value.

[0039] Embodiment 1

[0040] As shown in Figure 1 , Figure 2 , the retrievable vascular stent comprises a first stent 100, a second stent 200 and an isolation component.

[0041] The outer sidewall of the first stent 100 directly contacts the blood vessel wall to support the blood vessel, is woven by a nickel-titanium alloy wire, has good shape memory characteristics and can automatically shrink radially without external support, and the shrinkage force is smaller than the support force of the second stent 200. A biocompatible coating such as polyethylene terephthalate can be sprayed on the outer sidewall of the first stent 100 to reduce the inflammatory reaction with the blood vessel wall. When the stent is used in a functional expansion scene (such as implanting a stent carrying an electrode in a cerebral blood vessel to collect high-quality brain electrical signals and assist in the diagnosis, long-term monitoring or optimization of treatment of neurological diseases), the electrode is arranged on the outer sidewall of the first stent 100.

[0042] The second stent 200 is also made of a nickel-titanium alloy material and is coaxially arranged inside the first stent 100. After being implanted in the blood vessel, the second stent 200 is in an expanded state, provides radial support for the first stent 100 and makes the first stent 100 remain expanded to support the blood vessel.

[0043] As shown in Figure 2 , Figure 3 , Figure 4 , the isolation component comprises a first isolation film 110 and a second isolation film 210. The first isolation film 110 is made of polytetrafluoroethylene material and is fixed on the inner sidewall of the first stent 100 by laser welding. The second isolation film 210 is also made of polytetrafluoroethylene material and is fixedly arranged on the outer sidewall of the second stent 200. The first isolation film 110 and the second isolation film 210 contact each other and can effectively reduce the friction between the first stent 100 and the second stent 200.

[0044] In the stent extraction operation, the second stent 200 is gradually extracted from the inside of the first stent 100 by an external device, and the first stent 100 gradually loses support with the extraction of the second stent 200, and then automatically shrinks radially to reduce the embedding force with the side wall of the blood vessel, so as to realize the convenient extraction of the overall stent.

[0045] In the present embodiment, the recoverable vascular stent further comprises a connecting unit for maintaining the integrity of the first stent 100 and the second stent 200 during the extraction of the second stent 200, so as to avoid the first stent 100 being directly washed away by the blood flow due to radial shrinkage caused by the loss of support when the second stent 200 is extracted, and to ensure the synchronous withdrawal of the two.

[0046] The connecting unit in the present embodiment comprises a stop component 120 and a hook component 220. The stop component 120 is a rope-shaped stop ring, which has good flexibility and can be smoothly curled with the reduction of the first stent 100. The rope-shaped stop ring is fixedly arranged at the proximal end of the inner side wall of the first stent 100. The hook component 220 has two, which are arranged at the distal end of the second stent 200 at equal intervals in the circumferential direction. Each hook component 220 comprises a connecting rod 221 and a protrusion 222, the connecting rod 221 is made of nickel-titanium alloy material and is integrally formed with the second stent 200, which is arranged obliquely, and gradually approaches the axis direction of the second stent 200 from the end close to the second stent 200 to the end away from the second stent 200. The protrusion 222 is arranged at the distal end of the connecting rod 221 and forms a hook structure with the connecting rod 221, and the distance from the outer side wall of all the protrusions 222 to the axis of the second stent 200 is the same as the radius of the second stent 200. The purpose of such design is that the outer side wall of the protrusion 222 and the outer side wall of the second stent 200 are basically in the same cylindrical surface. When the second stent 200 is loaded into the first stent 100, the protrusion 222 will not increase the radial size of the second stent 200, thereby avoiding excessive radial extrusion on the first stent 100, ensuring uniform stress on the first stent 100, and at the same time, when the second stent 200 needs to be taken out from the first stent 200, the hook component 220 will not hook the side wall of the first stent 100, facilitating the smooth extraction of the second stent 200. In addition, this will also make the overall structure of the hook component 220 more compact, and when the second stent 200 is loaded into the first stent 100, it can reduce the occupation of the inner space of the first stent 100, avoid unnecessary interference with the first stent 100, and ensure the smoothness of the assembly process.

[0047] Further, the outer side surface of the protrusion 222 is arc-shaped, and preferably the protrusion 222 is entirely spherical. In this way, the spherical or arc-shaped surface is smoother in contact with the blood vessel wall during the implantation and removal of the stent, which can significantly reduce the risk of scraping the endothelial cells of the blood vessel. Vascular endothelial injury is an important inducement for postoperative thrombosis and vascular restenosis, and this design can effectively improve the safety of the operation.

[0048] The proximal end of the second stent 200 is provided with a tensioning component 230, which is made of high-strength medical nylon rope or an arc-shaped metal rod, and the two ends thereof are respectively movably connected to two positions radially opposite to each other of the second stent 200 through annular buckles. The middle part of the tensioning component 230 is provided with an engaging component 240, which is a buckle capable of cooperating with the buckle of the external removal device to facilitate the external device to pull the tensioning component 230.

[0049] When it is necessary to remove the vascular stent, the external removal device is operated, which has a recovery sheath 300 and a pulling wire 400, and the distal end of the pulling wire 400 has a buckle cooperating with the engaging component 240. After the distal end of the pulling wire 400 is fixedly connected to the engaging component 240, the tensioning component 230 is slowly pulled. As shown in Figure 5 As shown in Figure 6 Due to the fact that the hook-shaped component 220 is hung on the stop component 120, the second stent 200 moves together with the first stent 100 during the withdrawal process. At the same time, with the withdrawal of the second stent 200, the second stent 200 is gradually retracted into the recovery sheath 300, and the inner cavity of the recovery sheath 300 is smaller than the outer diameter of the second stent 200. Therefore, during the gradual retraction of the second stent 200, the second stent 200 is gradually retracted radially, and at this time, the first stent 100 supported by the second stent 200 is also gradually retracted radially to tightly adhere to the outer side wall of the second stent 200, and the embedding force thereof with the side wall of the blood vessel is gradually reduced. When the second stent 200 approaches the complete withdrawal of the first stent 100, the hook-shaped component 220 at the distal end of the second stent 200 contacts the stop component 120 at the proximal end of the first stent 100 and cooperates with the stop component 120. In this way, under the action of the connecting unit, the first stent 100 follows the second stent 200 to be pulled into the recovery sheath 300 and removed out of the body, thereby completing the entire stent removal process.

[0050] Example 2

[0051] The embodiment provides a structurally different connecting unit, which is different from that in the embodiment 1, in the embodiment, the connecting unit is a traction line made of medical high-strength polyester fiber, one end of the traction line is fixedly connected to the distal end of the second stent 200 through knotting, and the other end is also fixedly connected to the proximal end of the first stent 100 through knotting. When the second stent 200 is taken out from the first stent 100, the traction line is pulled tight to automatically contract the first stent 100 in the radial direction and is taken into the recovery sheath 300 together, so that the first stent 100 is prevented from remaining in the blood vessel.

[0052] Embodiment 3

[0053] The embodiment provides a different number of hook-shaped components, which is different from that in the embodiment 1, in the embodiment, the hook-shaped components 220 can be arranged at intervals along the circumference of the second stent 200.

[0054] Embodiment 4

[0055] The embodiment provides a different structure of the isolation component, which is different from that in the embodiment 1, in the embodiment, the first isolation film 110 is made of silica gel material and is fixedly arranged on the inner side wall of the first stent 100 through pasting, the outer side wall of the second stent 200 is not provided with an isolation film but is subjected to polishing treatment, and the surface is relatively smooth, so that the friction between the first isolation film 110 and the second stent 200 is reduced and the second stent 200 is ensured to be smoothly taken out.

[0056] Embodiment 5

[0057] The embodiment provides a different structure of the isolation component, which is different from that in the embodiment 1, in the embodiment, the isolation component only includes the second isolation film 210, the second isolation film 210 is fixedly arranged on the outer side wall of the second stent 200, the second isolation film 210 is made of polytetrafluoroethylene material, and the inner side wall of the first stent 100 is not provided with an isolation film but is subjected to polishing treatment and the surface is relatively smooth. In this way, when the second stent 200 is taken out, the sliding friction between the second stent 200 and the first stent 100 can be reduced.

[0058] Embodiment 6

[0059] The embodiment provides a different arrangement of the connecting unit, which is different from that in the embodiment 1, in the embodiment, the stop component 120 is arranged on the outer side wall of the distal end of the second stent 200, and the hook-shaped component 220 is arranged on the inner side wall of the proximal end of the first stent 100.

[0060] In summary, the recyclable vascular stent provided by the application effectively solves the problem that the existing vascular stent is difficult to take out, improves the safety and efficiency of taking out the vascular stent, and has a good clinical application prospect.

[0061] It can be understood that the above description is only exemplary, and the embodiments of the present application are not limited thereto.

[0062] The above is only the preferred embodiment of the present application, and is not used to limit the present application, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application is within the scope of the claims of the present application.

Claims

1. A recoverable vascular stent, characterized by, The application relates to a recoverable vascular stent, which comprises the following parts: a first stent (100), the outer side wall of which is used for directly supporting a blood vessel and can automatically contract in a radial direction; a second stent (200), which is coaxially arranged on the inner side of the first stent (100) and is used for supporting the first stent (100) to expand in a radial direction; an isolating part, which is arranged on the first stent (100) and / or the second stent (200) and is used for reducing the friction between the first stent (100) and the second stent (200); when the stent is taken out, the second stent (200) is gradually taken out from the inner side of the first stent (100), and the first stent (100) automatically contracts in a radial direction during the process of losing the support of the second stent (200) to reduce the embedding force with the side wall of the blood vessel, so that the taking out of the whole stent is facilitated.

2. The recoverable vascular stent of claim 1, wherein, The isolating part comprises a first isolating film (110) and a second isolating film (210), the first isolating film (110) is fixedly arranged on the inner side wall of the first stent (100), and the second isolating film (210) is fixedly arranged on the outer side wall of the second stent (200).

3. The recoverable vascular stent of claim 1, wherein, The recoverable vascular stent further comprises a connecting unit used for connecting the first stent (100) and the second stent (200) and used for keeping the first stent (100) and the second stent (200) in integrity during the process of taking out the second stent (200).

4. The recoverable vascular stent according to claim 3, wherein The connecting unit comprises stop parts (120) and hook-shaped parts (220) hung on the stop parts (120), one of the stop parts (120) and the hook-shaped parts (220) is arranged on the first stent (100), and the other is arranged on the second stent (200).

5. The recoverable vascular stent of claim 4, wherein, The stop parts (120) are arranged on the proximal end of the inner side wall of the first stent (100), and a plurality of the hook-shaped parts (220) are arranged on the distal end of the second stent (200) in a circumferential direction.

6. The recoverable vascular stent of claim 5, wherein, The hook-shaped parts (220) comprise connecting rods (221) and protrusions (222) arranged on the distal end of the connecting rods (221), and the protrusions (222) and the connecting rods (221) form a hook-shaped structure.

7. The recoverable vascular stent of claim 6, wherein, The connecting rods (221) are arranged in an inclined manner, and the connecting rods (221) gradually approach the axis of the second stent (200) from one end close to the second stent (200) to the other end away from the second stent (200), and the distance between the outer side wall of all the protrusions (222) and the axis of the second stent (200) is the same as the radius of the second stent (200).

8. The biorenewable vascular stent of claim 4, wherein, The stop parts (120) are rope-shaped stop rings arranged on the first stent (100).

9. The biorenewable vascular stent of any one of claims 1-8, wherein, The proximal end of the second stent (200) is provided with a tensioning part (230) used for tensioning the second stent (200).

10. The recoverable vascular stent of claim 9, wherein, The two ends of the tensioning part (230) are movably connected with two positions radially opposite to each other of the second stent (200), and the middle part of the tensioning part (230) is provided with an engaging part (240) matched with an external taking-out device.

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