A recyclable medical stent, its preparation method, and a recycling system

Abstract

The present invention relates to the technical field of medical devices, and discloses a retrievable medical stent, a preparation method thereof, and a recovery system. A retrievable medical stent includes a tubular body, and a plurality of layers of ring units are arranged along the length direction of the tubular body. The ring units are closed rings, and when the ring units are unfolded along the circumferential direction of the ring, they are in a wavy line structure. Compared with the existing medical stents made only of biodegradable materials, the present invention has better circumferential support and axial flexibility. Compared with the superelastic stents made only of materials such as nitinol, the present invention can be relatively easily recovered after being inserted into the human body, and will not remain in the human body after the treatment purpose is achieved, affecting the recovery of the human body. It solves the technical problem in the prior art that medical stents cannot achieve both overall retrievability or biodegradability by the human body while having good circumferential support and axial flexibility.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly to a retrievable medical stent, a preparation method thereof, and a recovery system. Background Art

[0002] In the medical field, stents have been widely used in implanting into human body lumens such as blood vessels, bile ducts, tracheas, etc. to maintain, open or expand the lumen. In order to enable the stent to have better support performance, the stent often uses materials with high elasticity such as nitinol alloy or cobalt-chromium alloy for preparation. Although these materials have good support performance, since they cannot be degraded, after the stent achieves the support purpose, it will still remain in the human body, which is not conducive to the recovery of the human body. Sometimes, it will even stimulate the human body to have an inflammatory reaction, and even a thrombus will appear in the stent, endangering life.

[0003] Currently, retrievable medical stents often use degradable materials such as magnesium alloy or zinc alloy for preparation. Since these stents have good degradable performance, they will degrade and be absorbed by the human body after completing the support task, thereby reducing the impact on the human body. However, the stents prepared with this kind of material usually have poor support performance due to insufficient elasticity.

[0004] Therefore, developing a retrievable stent with good support performance is a problem to be studied currently. Summary of the Invention

[0005] Aiming at the above defects, the purpose of the present invention is to provide a retrievable medical stent, a preparation method thereof, and a recovery system, to solve the technical problem in the prior art that the medical stent cannot achieve good circumferential support and axial flexibility while being integrally retrievable or degradable by the human body. The proposed retrievable medical stent is easy to recover and has good support performance.

[0006] To achieve this purpose, the present invention adopts the following technical solutions:

[0007] A retrievable medical stent includes a tubular body, and a plurality of layers of ring units are arranged along the length direction of the tubular body. The ring units are closed rings, and the ring units are unfolded into a wavy line structure along the circumferential direction of the ring;

[0008] The ring unit is provided with a wave crest part and a wave trough part along the axial direction, and connecting brackets are arranged between a plurality of layers of the ring units. The connecting brackets connect the wave crest parts and the wave trough parts between two adjacent ring units;

[0009] The ring unit is provided with a first connection point and a second connection point. The first connection point and the second connection point divide the ring unit into a first ring segment and a second ring segment. The first ring segment is made of a material that cannot be degraded in the human body, and the second ring segment is made of a material that can be degraded and absorbed by the human body in the human body;

[0010] The connecting bracket includes a first bracket and a second bracket. The first bracket connects the first connection point and the second connection point of adjacent ring units. The second bracket connects the peak part and the valley part of adjacent ring units that do not include the first connection point and the second connection point. The first bracket is made of a material that cannot be degraded in the human body, and the second bracket is made of a material that can be degraded and absorbed by the human body.

[0011] The tubular body is further provided with a recovery ring for connecting an external traction structure.

[0012] Preferably, the ring unit is composed of several structural units, the structural unit is V-shaped, the inflection point of the V-shaped structure of the structural unit is provided with an arc transition, the connection between adjacent structural units is provided with an arc transition, the structural units are sequentially connected in the same direction to form an annular wavy line structure, and adjacent two ring units are mirror-symmetrically arranged with respect to a cross-section B perpendicular to the axis A of the bracket. The connecting bracket is linear.

[0013] Preferably, the number of the structural units in the ring unit is at least 4.

[0014] The first connection point and the second connection point in the same ring unit are located in the same structural unit. The first connection point and the second connection point are adjacent peak part and valley part. The second ring segment is the shorter side between the first connection point and the second connection point in the ring unit. Only one first connection point, one second connection point and one second ring segment are provided in each ring unit, and the first connection point, the second connection point and the second ring segment of adjacent ring units are mirror-symmetrically arranged with respect to a cross-section B perpendicular to the axis A of the bracket.

[0015] Preferably, two recovery rings are provided. The first connection point of adjacent ring units is connected to the first connection point, and the second connection point of adjacent ring units is connected to the second connection point. The recovery rings are respectively arranged at the outermost first connection point or second connection point along the axis of the ring units at the head and tail ends of the tubular body.

[0016] Preferably, one first bracket and several second brackets are provided between adjacent two ring units.

[0017] Preferably, the materials of the first ring segment, the first bracket and the recovery ring are tungsten, platinum, zirconium, nickel, titanium metal or their alloys, and the materials of the second ring segment and the second bracket are iron, zinc, magnesium metal or their alloys.

[0018] Preferably, the recovery loop is connected to the first connection point of the first loop unit along the length direction of the tubular body. The recovery loop is provided with X-ray imaging marker points, and the material of the X-ray imaging marker points is gold, platinum or their alloys.

[0019] Preferably, the surface of the tubular body is provided with a film layer, and the film layer is formed by coating with a biodegradable polymer material.

[0020] A recovery system for a recyclable medical stent, comprising a recovery hook, a sheath tube and the above-mentioned recyclable medical stent. The recovery hook is movably inserted into the lumen of the sheath tube. The recovery hook is used for hooking the recovery loop of the recyclable medical stent, and the recovery hook is also used for pulling the degraded recyclable medical stent. The diameter of the recovery hook is smaller than the inner diameter of the recovery loop, the inner diameter of the sheath tube is larger than the outer diameter of the recovery loop, and the diameter of the sheath tube is 1 mm to 3 mm.

[0021] A preparation method for a recyclable medical stent, used for preparing the above-mentioned recyclable medical stent, comprising the following steps:

[0022] S1. Integrally form a linear structure composed of a first ring segment, a first stent and a recovery loop;

[0023] S2. Connect the second ring segment and the second stent to corresponding positions to obtain a stent;

[0024] S3. Perform a polishing surface treatment on the stent to obtain a recyclable medical stent.

[0025] The technical solution provided by the present invention may include the following beneficial effects:

[0026] A stable network tubular structure is integrally formed. Compared with the recyclable medical stent whose overall structure is woven in the prior art, the medical stent of the present invention has better support. After the degradable second ring segment and the second stent are degraded in the human body, the recyclable medical stent will only remain a linear stent structure, and the recovery loop can be easily hooked by the recovery hook, and the sheath tube and the recovery hook are used to recover the medical stent. Compared with the existing medical stents made only of biodegradable materials, the present invention has better circumferential support and axial flexibility. Compared with the superelastic stents made only of materials such as nitinol alloy, the present invention can be more easily recovered after being introduced into the human body and will not remain in the human body to affect the recovery of the human body after the treatment purpose is achieved. It solves the technical problem in the prior art that the medical stent cannot achieve both the overall recyclability or biodegradability by the human body and has good circumferential support and axial flexibility.

[0027] The first connection point, the second connection point, the second ring segment, and the recovery ring are all arranged near the intersection line C along the length direction on the same side in the tubular body, ensuring the circumferential force balance of the tubular body and solving the problem that the recyclable medical stent is prone to overall twisting and rotational deformation due to uneven circumferential force during use.

[0028] After the surface of the recyclable medical stent is coated with a film, firstly, the mechanical properties of the recyclable medical stent can be enhanced. Secondly, it can prevent tissue cells from proliferating inside the stent and blocking the recyclable medical stent after the recyclable medical stent is implanted into the human body. Thirdly, during the degradation of the coating film, a part of it will remain on the recyclable medical stent, providing a certain lubricating effect during the recovery of the recyclable medical stent and making the recovery easier.

[0029] The recyclable medical stent can be processed and prepared by using laser engraving, lathe cutting, and 3D printing technologies, and the preparation method has low difficulty. Brief Description of the Drawings

[0030] Figure 1 It is a schematic structural diagram of the recyclable medical stent before degradation according to an embodiment of the present invention.

[0031] Figure 2 It is a schematic structural diagram of the recyclable medical stent after degradation according to an embodiment of the present invention.

[0032] Figure 3 It is a schematic unfolded structural diagram of the recyclable medical stent before degradation according to an embodiment of the present invention.

[0033] Figure 4 It is a schematic unfolded structural diagram of the recyclable medical stent after degradation according to an embodiment of the present invention.

[0034] Figure 5 It is a schematic unfolded structural diagram of the recyclable medical stent before degradation according to another embodiment of the present invention.

[0035] Figure 6 It is a schematic unfolded structural diagram of the recyclable medical stent after degradation according to another embodiment of the present invention.

[0036] Figure 7 It is a schematic diagram of the use of the recovery system according to an embodiment of the present invention.

[0037] Wherein: ring unit 1, structural unit 10, peak portion 11, valley portion 12, connecting stent 2, first stent 21, second stent 22, first connection point 31, second connection point 32, first ring segment 41, second ring segment 42, recovery ring 5, recovery hook 61, sheath 62, stent axis A, cross-section B, intersection line C. Detailed Embodiments

[0038] Embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention.

[0039] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the features defined as "first" and "second" may explicitly or implicitly include one or more of such features, which are used to distinguish and describe the features, without order or importance.

[0040] In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

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

[0042] Embodiments of the present invention will be described below with reference to the accompanying drawings.

[0043] A recyclable medical stent includes a tubular body. Along the length direction of the tubular body, there are provided several layers of ring units 1. The ring units 1 are closed rings, and when the ring units 1 are unfolded along the circumferential direction of the ring, they are in a wavy line structure;

[0044] The ring units 1 are provided with wave crest portions 11 and wave trough portions 12 along the axial direction. Between several layers of the ring units 1, there are provided connection brackets 2. The connection brackets 2 connect the wave crest portions 11 and the wave trough portions 12 between adjacent two of the ring units 1;

[0045] The ring unit 1 is provided with a first connection point 31 and a second connection point 32. The first connection point 31 and the second connection point 32 divide the ring unit 1 into a first ring segment 41 and a second ring segment 42. The first ring segment 41 is made of a material that cannot be degraded in the human body, and the second ring segment 42 is made of a material that can be degraded and absorbed by the human body in the human body;

[0046] The connection bracket 2 includes a first bracket 21 and a second bracket 22. The first bracket 21 connects the first connection point 31 and the second connection point 32 of adjacent ring units 1. The second bracket 22 connects the peak portion 11 and the valley portion 12 of adjacent ring units 1 that do not include the first connection point 31 and the second connection point 32. The first bracket 21 is made of a material that cannot be degraded in the human body, and the second bracket 22 is made of a material that can be degraded and absorbed by the human body in the human body;

[0047] The tubular body is further provided with a recovery ring 5 for connecting an external traction structure.

[0048] As Figure 1 、 Figure 2 、 Figure 3 and Figure 4 As shown, with this structure, the peak portions 11 and valley portions 12 between multiple ring units 1 are directly opposite and fixedly connected through the connection bracket 2, forming a stable network tubular structure as a whole. Compared with the prior art recyclable medical stent whose overall structure is woven, the medical stent of the present invention has better supportability. After the degradable second ring segment 42 and the second bracket 22 are degraded in the human body, the recyclable medical stent will only remain a linear stent structure, and the recovery ring 5 can be easily hooked by the recovery hook 61, and the medical stent can be recovered by using the sheath tube and the recovery hook 61. Compared with the existing medical stents made only of degradable materials, the present invention has better circumferential supportability and axial flexibility. Compared with the superelastic stents made only of materials such as nitinol alloy, the present invention can be relatively easily recovered after being inserted into the human body and will not remain in the human body to affect the recovery of the human body after the treatment purpose is achieved. It solves the technical problem in the prior art that the medical stent cannot achieve both overall recyclability or degradation by the human body and has good circumferential supportability and axial flexibility.

[0049] Preferably, the ring unit 1 is composed of a plurality of structural units 10. The structural unit 10 is V-shaped. The inflection point of the V-shaped structure of the structural unit 10 is provided with an arc transition, and the connection between adjacent structural units 10 is provided with an arc transition. The structural units 10 are sequentially connected in the same direction to form a ring-shaped wavy line structure. Adjacent two ring units 1 are mirror-symmetrically arranged with respect to a cross-section B perpendicular to the axis A of the stent, and the connection bracket 2 is linear.

[0050] AsFigure 3 As shown, in a specific embodiment, the connecting bracket 2 is in the shape of a short rod. In the same layer of ring units 1, the structural units 10 are arranged in the same V-shaped direction. In adjacent two layers of ring units 1, the V-shapes of the structural units 10 are arranged in opposite directions. The connecting bracket 2 connects the tops of the V-shapes of the structural units 10 in adjacent two layers of ring units 1, forming a net-shaped tubular body with a mesh similar to a rhombus. With this structure, the overall bracket has good circumferential support and axial flexibility.

[0051] Preferably, the number of the structural units 10 in the ring unit 1 is at least 4;

[0052] The first connection point 31 and the second connection point 32 in the same ring unit 1 are located in the same structural unit 10. The first connection point 31 and the second connection point 32 are adjacent peak portions 11 and valley portions 12. The second ring segment 42 is the shorter side between the first connection point 31 and the second connection point 32 in the ring unit 1. Only one first connection point 31, one second connection point 32 and one second ring segment 42 are provided in each ring unit 1, and the first connection point 31, the second connection point 32 and the second ring segment 42 of adjacent ring units 1 are arranged symmetrically with respect to a cross-section B perpendicular to the axis A of the bracket.

[0053] Preferably, two recovery rings 5 are provided. The first connection point 31 of adjacent ring units 1 is connected to the first connection point 31, and the second connection point 32 of adjacent ring units 1 is connected to the second connection point 32. The recovery rings 5 are respectively arranged at the first connection point 31 or the second connection point 32 on the outermost side along the axis at the head and tail ends of the tubular body.

[0054] As Figure 3 shown, with this structure, the first connection point 31, the second connection point 32, the second ring segment 42 and the recovery ring 5 are all arranged near an intersection line C along the length direction on the same side of the tubular body, ensuring the circumferential force balance of the tubular body and solving the problem that the bracket is prone to overall twisting and rotational deformation due to uneven circumferential force during use.

[0055] As Figure 6 shown, with the structure of two recovery rings 5 at the head and tail, the medical stent can be recovered from a better direction according to the actual situation.

[0056] Preferably, one first bracket 21 and several second brackets 22 are provided between two adjacent ring units 1.

[0057] With this structure, after the degradable second ring segment 42 and the second stent 22 in the tubular body are completely degraded, the remaining first ring segment 41 and the first stent 21 are connected into a meandering curve structure. At the same time, the recovery rings 5 are located at both end points of the head and tail of the curve. The recovery hook 61 is used to pass through the sheath tube to hook one of the recovery rings 5, and a pulling force is applied to deform the stent of the curve structure into a structure closer to a straight line and pull it into the sheath tube for easy recovery.

[0058] As Figure 3 shown, in one embodiment, the number of the second stents 22 between adjacent ring units 1 is five.

[0059] As Figure 5 shown, in a more preferred embodiment, the number of the second stents 22 between adjacent ring units 1 is two, which can greatly reduce the workload during stent welding.

[0060] Preferably, the materials of the first ring segment 41, the first stent 21 and the recovery ring 5 are tungsten, platinum, zirconium, nickel, titanium metal or their alloys, and the materials of the second ring segment 42 and the second stent 22 are iron, zinc, magnesium or their alloys.

[0061] With this structure, most of the support structures in the stent as a whole, namely the first ring segment 41, the first stent 21 and the recovery ring 5, are made of tungsten, platinum, zirconium, nickel, titanium and other metals or their alloys with good elasticity and non-degradable properties, while the second ring segment 42 and the second stent 22 are made of iron, zinc, magnesium and other or their alloys that can be degraded in the human body. Before degradation, the stent as a whole has better circumferential support and axial flexibility.

[0062] Preferably, the connection between the first ring segment 41 and the second ring segment 42, and between the first ring segment 41 and the second stent 22 is welded.

[0063] In a specific embodiment, after the structure of the recovery ring 5, the first ring segment 41 and the first stent 21 is integrally formed, the second ring segment 42 and the second stent 22 are welded by gas arc welding to form a network tubular structure. As a simple replacement, methods such as ion welding, laser welding and electron beam welding can be used for connection and fixation.

[0064] Preferably, the welding materials used for welding are iron, zinc, magnesium, gold, silver metal or their alloys.

[0065] Since the melting points of the non-degradable material used in the first ring segment 41 and the degradable materials used in the second ring segment 42 and the second bracket 22 differ significantly, to ensure a good connection, soldering is performed using soldering materials with relatively low melting points such as iron, zinc, magnesium, gold, silver metals or their alloys. The connection positions between the first ring segment 41, the second ring segment 42 and the second bracket 22 are completely covered in the molten soldering material, making the connection stronger. Moreover, using soldering materials for soldering requires lower equipment requirements compared to methods such as laser welding for solderless welding.

[0066] Preferably, the recovery ring 5 connects to the first connection point 31 of the first ring unit 1 along the length direction of the tubular body. The recovery ring 5 is provided with X-ray imaging marker points, and the material of the X-ray imaging marker points is gold, platinum or their alloys.

[0067] The X-ray imaging marker points facilitate positioning the recovery ring 5 in the human body and facilitate the recovery of the stent.

[0068] Preferably, the surface of the tubular body is provided with a film layer, and the film layer is formed by coating with a degradable polymer material.

[0069] In a specific embodiment, the coating material is selected from at least one of degradable polymer materials such as polylactic acid, polyglycolic acid, polycaprolactone and polyethylene glycol. After the surface of the retrievable medical stent is coated, firstly, it can increase the mechanical properties of the retrievable medical stent. Secondly, it can prevent tissue cells from proliferating inside the retrievable medical stent after the retrievable medical stent is implanted into the human body, thus blocking the stent. Thirdly, when the film layer degrades, part of it will remain on the retrievable medical stent, providing a certain lubricating effect during the recovery of the retrievable medical stent and making the recovery easier.

[0070] Specifically, the diameter of the tubular body is 2 mm to 10 mm, and the wire diameter of the tubular body is 0.04 mm to 0.3 mm.

[0071] After the tubular body is manufactured, surface treatments such as sandblasting and polishing need to be performed on the stent.

[0072] A recovery system for a retrievable medical stent includes a recovery hook 61, a sheath 62 and the above-mentioned retrievable medical stent. The recovery hook is movably disposed in the lumen of the sheath 62. The recovery hook is used to hook the recovery ring of the retrievable medical stent, and the recovery hook is also used to pull the degraded retrievable medical stent. The diameter of the recovery hook 61 is smaller than the inner diameter of the recovery ring 5, the inner diameter of the sheath 62 is larger than the outer diameter of the recovery ring 5, and the diameter of the sheath 62 is 1 mm to 3 mm.

[0073] As Figure 7As shown, with this structure, when retrieving the degradable recyclable medical stent after degradation, the retrieval hook 61 is placed in the sheath 62 and inserted into the human body. The retrieval hook 61 hooks the retrieval ring 5 to retrieve the degradable recyclable medical stent. The overall shape of the degradable recyclable medical stent deforms into a linear shape and is retrieved into the sheath 62 and removed from the human body.

[0074] In a specific embodiment, the first ring segment 41 is made of nitinol alloy material with certain elasticity and can be bent and deformed to facilitate being received into the sheath 62.

[0075] A preparation method of a recyclable medical stent for preparing the above-mentioned recyclable medical stent includes the following steps:

[0076] S1. Integrally form a linear structure composed of the first ring segment 41, the first stent 21, and the retrieval ring 5;

[0077] S2. Connect the second ring segment 42 and the second stent 22 to the corresponding positions to obtain a stent;

[0078] S3. Perform a polishing surface treatment on the stent to obtain a recyclable medical stent.

[0079] In a specific embodiment, use laser engraving technology to engrave a nickel alloy tube into an overall linear structure composed of the first ring segment 41, the first stent 21, and the retrieval ring 5. Then weld the second ring segment 42 and the second stent 22 made of magnesium alloy material to the corresponding positions. Then inlay X-ray imaging marker points made of platinum material on the retrieval ring 5. Finally, perform sandblasting and polishing on the stent to grind off sharp edges and burrs, and perform film coating treatment. Manually bend, stretch, and compress the recyclable medical stent for inspection, requiring that the welded joints are not loose and the overall recyclable medical stent does not deform or break.

[0080] In another embodiment, the linear structure in step S1 is made by laser engraving on an alloy plate. With this preparation method, the requirements for equipment are lower. However, since the produced linear stent structure is in a planar state, it needs to be coated and fixed on a round bar with a suitable size for heat treatment and shaping. After obtaining a tubular linear stent structure, the second ring segment 42 and the second stent 22 are welded on.

[0081] As a simple replacement, alloy tubes or alloy plates can also be processed by machine tool turning.

[0082] In another embodiment, the linear structure in step S1 is made by metal 3D printing. With this preparation method, the process is the simplest and the cost is the lowest. However, since the recyclable medical stent is relatively small, the accuracy requirements for the 3D printer are relatively high. And because the parts printed by 3D printing are relatively rough, more time and cost are required for sandblasting and polishing surface treatment.

[0083] In a more preferred embodiment, when making a linear structure in step S1, an auxiliary bracket is made at the position where the second ring segment 42 and the second bracket 22 need to be welded at the same time to form a complete network tubular structure. Subsequently, the auxiliary brackets are cut off one by one and the second ring segment 42 or the second bracket 22 is welded accordingly. With this preparation method, since only one connection structure needs to be welded at a time and the bracket as a whole still maintains a network tubular shape, fixing and welding are easier.

[0084] Specifically, for the connection method in step S2, at least one of gas arc welding, ionic welding, laser welding, and electron beam welding can be used for connection and fixation.

[0085] Other components and operations according to the embodiments of the present invention are known to those of ordinary skill in the art and will not be described in detail here.

[0086] In the description of this specification, the descriptions with reference to terms such as "embodiment", "example", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0087] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and purposes of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A recyclable medical stent, characterized in that: It includes a tubular body, and several layers of ring units are arranged along the length direction of the tubular body. The ring units are closed rings, and the ring units are unfolded into a wavy line structure along the circumferential direction of the ring. The ring units are provided with wave crest parts and wave trough parts along the axial direction, and connecting brackets are arranged between several layers of the ring units. The connecting brackets connect the wave crest parts and the wave trough parts between two adjacent ring units. The ring units are provided with a first connection point and a second connection point. The first connection point and the second connection point divide the ring units into a first ring segment and a second ring segment. The first ring segment is made of a material that cannot be degraded in the human body, and the second ring segment is made of a material that can be degraded and absorbed by the human body in the human body. The connecting brackets include a first bracket and a second bracket. The first bracket connects the first connection point and the second connection point of adjacent ring units. The second bracket connects the wave crest parts and the wave trough parts of adjacent ring units that do not include the first connection point and the second connection point. The first bracket is made of a material that cannot be degraded in the human body, and the second bracket is made of a material that can be degraded and absorbed by the human body in the human body. The tubular body is further provided with recovery rings, and the recovery rings are used for connecting with an external traction structure. Each of the ring units is only provided with one first connection point, one second connection point and one second ring segment. One first bracket is arranged between two adjacent ring units. After all the degradable second ring segments and second brackets in the tubular body are degraded, the remaining first ring segments and first brackets are connected into a circuitous curve structure.

2. The recyclable medical stent according to claim 1, characterized in that: The ring units are composed of several structural units. The structural units are V-shaped. An arc transition is provided at the inflection point of the V-shaped structure of the structural units, and an arc transition is provided at the connection of adjacent structural units. The structural units are sequentially connected in the same direction to form a ring-shaped wavy line structure. Two adjacent ring units are mirror-symmetrically arranged with respect to a cross-section B perpendicular to the axis A of the bracket. The connecting brackets are linear.

3. The recyclable medical stent according to claim 2, wherein: The number of the structural units in the ring units is at least 4. The first connection point and the second connection point in the same ring unit are located in the same structural unit. The first connection point and the second connection point are adjacent wave crest parts and wave trough parts. The second ring segment is the shorter side between the first connection point and the second connection point in the ring unit. The first connection points, the second connection points and the second ring segments of adjacent ring units are mirror-symmetrically arranged with respect to a cross-section B perpendicular to the axis A of the bracket.

4. The recyclable medical stent according to claim 3, characterized in that: Two recovery rings are provided. The first connection points of adjacent ring units are connected to each other, and the second connection points of adjacent ring units are connected to each other. The recovery rings are respectively arranged at the first connection points or the second connection points on the outermost side along the axial direction of the ring units at the head and tail ends of the tubular body.

5. The recyclable medical stent according to claim 3, wherein: Several second brackets are arranged between two adjacent ring units.

6. The recyclable medical stent according to claim 1, wherein: The materials of the first ring segment, the first stent and the recovery ring are tungsten, platinum, zirconium, nickel, titanium metal or their alloys, and the materials of the second ring segment and the second stent are iron, zinc, magnesium metal or their alloys.

7. The recyclable medical stent according to claim 1, wherein: The recovery ring is connected to the first connection point of the first ring unit along the length direction of the tubular body, and the recovery ring is provided with X-ray imaging marker points, and the materials of the X-ray imaging marker points are gold, platinum or their alloys.

8. A recyclable medical stent according to any one of claims 1-7, characterized in that: The surface of the tubular body is provided with a coating layer, and the coating layer is formed by coating with a biodegradable polymer material.

9. A recycling system for a recyclable medical stent, characterized in that: It includes a recovery hook, a sheath tube and the retrievable medical stent according to any one of claims 1-8. The recovery hook is movably disposed in the lumen of the sheath tube. The recovery hook is used for hooking with the recovery ring of the retrievable medical stent, and the recovery hook is also used for pulling the degraded retrievable medical stent. The diameter of the recovery hook is smaller than the inner diameter of the recovery ring, the inner diameter of the sheath tube is larger than the outer diameter of the recovery ring, and the diameter of the sheath tube is 1 mm to 3 mm.

10. A preparation method of a recyclable medical stent for preparing the recyclable medical stent according to any one of claims 1-8, characterized in that It includes the following steps: S1. Integrally form a linear structure composed of a first ring segment, a first stent and a recovery ring; S2. Connect the second ring segment and the second stent to the corresponding positions to obtain a stent; S3. Perform a polishing surface treatment on the stent to obtain a retrievable medical stent.

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