Convertible vena cava filter and assembly thereof

Abstract

The invention relates to the technical field of medical equipment, in particular to a convertible vena cava filter and a combination thereof. The convertible vena cava filter comprises a supporting device and a restraining ring. The supporting device comprises a plurality of supporting parts, one end of each supporting part can be limited by the restraint ring to form a contraction structure, and the other end of each supporting part forms an expansion structure; the restraint ring is made of a degradable material and comprises a plurality of limiting parts and a plurality of connecting parts, every two adjacent limiting parts are connected through the corresponding connecting part, and the limiting parts are fixed to the supporting part; the connecting part is made to be degraded prior to the limiting part. According to the convertible vena cava filter and the combination thereof, the connecting part is degraded prior to the limiting part, the supporting part is bounced off and supported on the blood vessel wall, the risk that degradable materials fall off is reduced, the problem that an umbrella-shaped structure and a lantern-shaped structure are difficult to recycle is solved, and the convertible vena cava filter and the combination thereof have the advantages of the umbrella-shaped structure and the barrel-shaped structure at the same time; and the problem of pulmonary embolism caused by falling of the degradable material is also avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a convertible inferior vena cava filter and its assembly. Background Art

[0002] An inferior vena cava filter (English full name: Inferior Vena Cava Filter; English abbreviation: IVCF) is a device used to prevent pulmonary embolism caused by the detachment of emboli formed by deep vein thrombosis in the inferior vena cava system. The main function of the filter is to capture emboli and prevent pulmonary thrombus. Currently, interventional surgery is generally used to implant the filter: usually, puncture is performed in the iliac vein or jugular vein, etc., and the filter is transmitted to the placement site via the vein using a delivery device and then released. The placement site can be above or below the kidney, etc. The inferior vena cava filter plays an important role in clinical applications. However, long-term retention of the filter in the body may cause obstruction of the inferior vena cava, affect blood flow, increase the recurrence of pulmonary embolism, recurrence of deep vein thrombosis in the lower extremities, and the risk related to thrombus syndrome. Clinically, the filter is generally removed at an appropriate time to reduce the complications caused by long-term retention.

[0003] Currently, the filters sold on the market are mainly divided into umbrella-shaped and lantern-shaped according to their shapes. After the umbrella-shaped filter is released, it is prone to tilt. After the filter topples, the recovery hook will stick to the wall, resulting in the capture device being unable to catch the recovery hook and the recovery failure. The lantern-shaped filter has a certain anti-tilting ability after being released. However, because the contact area between the filter and the blood vessel wall is large, endothelial cells will grow on the filter generally within 2 - 3 weeks. Theoretically, within 2 weeks is the best recovery time, but many patients cannot recover the filter within this time. After the lantern-shaped filter is implanted for a long time, the filter is wrapped by endothelial cells, and forced recovery will cause venous injury / rupture, and even recovery failure. Summary of the Invention

[0004] The present invention provides a convertible inferior vena cava filter and its assembly to solve the defect of difficult recovery of the inferior vena cava filter in the prior art.

[0005] The present invention provides a convertible inferior vena cava filter, including: a support device and a restraint ring; The support device includes a plurality of support parts and recovery hooks. One end of the support part can be limited by the restraint ring to form a contraction structure, and the other end of the support part forms an expansion structure. The recovery hook is provided at least at one end of one of the support parts; The restraint ring is made of a biodegradable material, and the restraint ring is a rigid structure before degradation. The restraint ring includes a plurality of limiting parts and a plurality of connecting parts. The plurality of limiting parts are arranged along the circumferential direction of the restraint ring, and adjacent two limiting parts are connected by a connecting part. The limiting part is fixed at one end of the support part for limiting and restraining the support part; The connecting part is made to degrade prior to the limiting part; After the connecting part degrades and fails, the limiting part expands along with one end of the supporting part and supports on the blood vessel wall.

[0006] According to the convertible inferior vena cava filter provided by the present invention, the connecting part is a first groove formed on the inner wall and / or the outer wall of the restraining ring, and the thickness of the first groove is less than that of the limiting part.

[0007] According to the convertible inferior vena cava filter provided by the present invention, the depth direction of the first groove is arranged parallel to the radial direction of the restraining ring.

[0008] According to the convertible inferior vena cava filter provided by the present invention, the limiting part is a second groove formed on the inner wall of the restraining ring, and one end of the supporting part is embedded in the second groove.

[0009] According to the convertible inferior vena cava filter provided by the present invention, the limiting part is a first through hole formed on the side wall of the restraining ring, one end of the supporting part forms a first bent part, and the first bent part is inserted and limited in the first through hole.

[0010] According to the convertible inferior vena cava filter provided by the present invention, the supporting part fits on the inner side of the restraining ring, and the first bent part is inserted from the inner side of the restraining ring and extends to the outer side of the restraining ring; or, the supporting part fits on the outer side of the restraining ring, and the first bent part is inserted from the outer side of the restraining ring and extends to the inner side of the restraining ring.

[0011] According to the convertible inferior vena cava filter provided by the present invention, the limiting part includes a second through hole formed on the upper end wall of the restraining ring and a third through hole on the lower end wall of the restraining ring, one end of the supporting part forms a second bent part, and one end of the supporting part passes through the third through hole and the second bent part is limited in the second through hole.

[0012] According to the convertible inferior vena cava filter provided by the present invention, the connecting part includes: a first restraining wire; The limiting part includes: a second restraining wire, the second restraining wire is connected end to end with the first restraining wire to form a restraining collar, and the restraining collar is sleeved on two adjacent supporting parts; a thickening sleeve, which is sleeved on the supporting part along the thickness direction of the second restraining wire and is fixedly connected with the second restraining wire. According to the convertible inferior vena cava filter provided by the present invention, the supporting part includes: a support rod and a fixing hook; The support rod is made of non-degradable material; The fixed hook is provided at one end of the support rod and is made of a biodegradable material; The recovery hook is provided at least at the other end of the support rod of at least one of the support portions.

[0013] The present invention also provides a convertible vena cava filter assembly, comprising: a plurality of convertible vena cava filters in the embodiments of the present invention, and adjacent convertible vena cava filters are connected through the respective support devices.

[0014] A convertible vena cava filter provided by the present invention comprises: a support device and a restraint ring. The support device comprises a plurality of support portions and recovery hooks. One end of the support portion can be limited by the restraint ring to form a contracted structure, and the other end of the support portion forms an expanded structure. The recovery hook is provided at least at one end of one of the support portions; the restraint ring is made of a biodegradable material, and the restraint ring is a rigid structure before degradation. The restraint ring comprises a plurality of limiting portions and a plurality of connecting portions. The plurality of limiting portions are arranged along the circumferential direction of the restraint ring, and adjacent two limiting portions are connected through the connecting portion. The limiting portion is used to limit and restrain the support portion. For the convertible vena cava filter provided by the present invention, under the restraint and limitation of the restraint ring, the support device is integrally in an umbrella-shaped structure in the initial stage, and the thrombus capture effect has good stability; in the later stage, since the restraint ring is made of a biodegradable material, after its degradation, the restraint fails, and the support device self-expands and returns to a cylindrical structure, which can avoid the problem that the long-term indwelling of the filter hinders blood flow; the whole support device can be taken out by using the recovery hook, which is convenient for recovery. It can be seen that for the convertible vena cava filter provided by the present invention, the biodegradable restraint ring provides a restraint effect before degradation, and the support device is in an umbrella-shaped structure. The connecting portion degrades prior to the limiting portion. After the connecting portion degrades, the support portion springs open and supports on the blood vessel wall, and the limiting portion is fixed on the blood vessel wall along with the support portion, and endothelial cells creep on the degradable material, thereby reducing the risk of shedding of the degradable material. On the one hand, it overcomes the problem of difficult recovery existing in the umbrella-shaped structure and the lantern-shaped structure in the prior art, and simultaneously has the advantages of both the umbrella-shaped structure and the cylindrical structure. On the other hand, it avoids the problem of pulmonary embolism caused by the shedding of the degradable material.

[0015] Furthermore, a convertible vena cava filter assembly provided by the present invention comprises a plurality of convertible vena cava filters in the embodiments of the present invention, and thus has the same advantages as above. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0017] Figure 1 It is a schematic diagram of the overall structure of the convertible vena cava filter provided in Embodiment 2 of the present invention when it is in the umbrella structure.

[0018] Figure 2 It is a schematic diagram of the overall structure of the convertible vena cava filter provided in Embodiment 2 of the present invention when it is in the cylindrical structure.

[0019] Figure 3 It is a schematic diagram of the overall structure of the convertible vena cava filter with a double-umbrella structure provided in one of the embodiments of the present invention.

[0020] Figure 4 It is one of the schematic diagrams of the structure of the restraint ring and the support rod provided in Embodiment 1 of the present invention.

[0021] Figure 5 It is one of the schematic diagrams of the structure of the restraint ring and the support rod provided in Embodiment 1 of the present invention.

[0022] Figure 6 It is one of the schematic diagrams of the structure of the restraint ring and the support rod provided in Embodiment 2 of the present invention.

[0023] Figure 7 It is one of the schematic diagrams of the structure of the restraint ring and the support rod provided in Embodiment 2 of the present invention.

[0024] Figure 8 It is one of the schematic diagrams of the structure of the restraint ring and the support rod provided in Embodiment 3 of the present invention.

[0025] Figure 9 It is one of the schematic diagrams of the structure of the restraint ring and the support rod provided in Embodiment 3 of the present invention.

[0026] Figure 10 It is one of the schematic diagrams of the structure of the restraint ring and the support rod provided in Embodiment 4 of the present invention.

[0027] Figure 11 It is one of the schematic diagrams of the structure of the restraint ring and the support rod provided in Embodiment 4 of the present invention.

[0028] Figure 12 is Figure 1 a partial structural schematic diagram of A in

[0029] Figure 13 It is a schematic diagram of the structure of the restraint ring and the support rod provided in Embodiment 5 of the present invention.

[0030] Figure 14 It is a schematic diagram of the structure of the convertible vena cava filter assembly provided in the embodiments of the present invention.

[0031] Reference numerals: 100: Constraint ring; 101: First groove; 102: Second groove; 103: First through-hole; 104: Second through-hole; 105: Third through-hole; 106: First constraint line; 107: Second constraint line; 108: Thickening sleeve; 200: Support device; 210: Support part; 211: Support rod; 2111: Positioning groove; 2112: First bending part; 2113: Second bending part; 212: Fixed hook; 213: Recycling hook. Detailed implementation mode

[0032] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0033] In the description of this implementation mode, it should be understood that the orientation or positional relationship indicated by terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this implementation mode and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to this implementation mode.

[0034] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of this implementation mode, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0035] In this implementation mode, unless otherwise clearly specified and limited, terms such as "set", "installed", "connected", "connected", "fixed", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and can be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in this implementation mode can be understood according to specific circumstances.

[0036] In an embodiment of the present invention, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the horizontal height of the first feature is less than that of the second feature.

[0037] The following Figures 1 - 13 describes a convertible inferior vena cava filter of the present invention. The convertible inferior vena cava filter includes: a support device 200 and a restraint ring 100.

[0038] Wherein, the support device 200 includes a plurality of support portions 210 and a retrieval hook 213. One end of the support portion 210 can be limited by the restraint ring 100 to form a contraction structure, and the other end of the support portion 210 forms an expansion structure. The retrieval hook 213 is disposed at least at one end of one of the support portions 210; the restraint ring 100 is made of a biodegradable material, and the restraint ring 100 is a rigid structure before degradation. The restraint ring 100 includes a plurality of limiting portions and a plurality of connecting portions. The plurality of limiting portions are arranged along the circumferential direction of the restraint ring 100, and adjacent two limiting portions are connected by a connecting portion. The limiting portion is fixed at one end of the support portion 210 for limiting and restraining the support portion 210.

[0039] The connecting portion is made to degrade prior to the limiting portion. When the connecting portion degrades and fails, the limiting portion expands along with one end of the support portion 210 and supports on the blood vessel wall.

[0040] Specifically, the support device 200 is supported on the inner wall of the blood vessel. A ring structure is formed by connecting a plurality of support portions 210. The upper end (or lower end) of the support portion 210 is constrained by the restraint ring 100, so that the upper end (or lower end) of the plurality of support portions 210 forms a contraction structure, and the other end forms an expansion structure. That is to say, the outer diameter of the ring structure formed at one end of the support device 200 is smaller than the outer diameter of the ring structure formed at the other end. Under the limiting and restraining of the restraint ring 100, the support device 200 is in an umbrella-shaped structure as a whole.

[0041] The restraining ring 100 has an annular structure and is composed of a plurality of limiting parts and a plurality of connecting parts. Each limiting part forms a limiting restraint on a supporting part 210, and the adjacent limiting parts are connected by the connecting parts to form an annular structure, thereby realizing the limiting effect on the supporting device 200. Moreover, since the connecting parts degrade prior to the limiting parts, when the connecting parts degrade, the limiting parts have not completely degraded and still remain fixed on the supporting part 210. When the connecting parts degrade and fail, the supporting part 210 immediately springs open and expands to support against the blood vessel wall, and the limiting parts also adhere to the blood vessel wall along with the springing open of the supporting part 210. Endothelial cells crawl on the degradable material, thereby reducing the risk of shedding of the degradable material, and further avoiding the problem of pulmonary embolism caused by the shedding of the degradable material.

[0042] Regarding the materials of the supporting device 200 and the restraining ring 100: 1. The main structure of the supporting device 200, that is, the support rod 211 and the recovery hook 213 introduced in the following embodiments, are made of non-degradable materials, while the fixing hook 212 is made of degradable materials. However, the degradation of the fixing hook 212 should lag behind that of the connecting parts to ensure that the restraining ring 100 degrades first, and then the fixing hook 212 degrades. The way to achieve this can be to increase the size of the fixing hook 212 so that under the same degradation rate, the degradation of the fixing hook 212 is completed later.

[0043] 2. The restraining ring 100 is made of degradable materials, that is, both the limiting parts and the connecting parts can be made of degradable materials. Before degradation, it has a rigid structure and has a restraining effect on the supporting part 210. Preferably, the connecting parts degrade prior to the limiting parts, that is, after the connecting parts degrade first, the limiting parts still remain connected to the supporting part 210, and then the limiting parts gradually degrade.

[0044] Of course, the restraining ring 100 can be entirely made of degradable materials, or partially made of degradable materials.

[0045] Specifically, in order to achieve the degradation of the connecting parts prior to the limiting parts, two ideas can be adopted: 1. Made of materials with different degradation rates, and the connecting parts are made of materials with a fast degradation rate, while the limiting parts are made of materials with a slow degradation rate; 2. Made of the same material, and the volume / thickness of the connecting parts is made smaller, so that under the same material, the connecting parts are degraded first and lose their mechanical properties. When the connecting parts are completely degraded, the limiting parts have not been completely degraded. In the actual preparation process, because the second method can use the same material, it is convenient for material selection and preparation. Taking the second method as an example, it can be achieved by reducing the thickness of the connecting parts, or by constructing a hollow structure inside the connecting parts, etc., to make it degrade prior to the limiting parts.

[0046] Since the restraint ring 100 in this embodiment is made of a degradable material, before the restraint ring 100 degrades, it provides restraint and limitation for the support device 200, making the overall support device 200 in an umbrella-like structure; when the restraint ring 100 degrades, the connecting part degrades first, releasing the connection between the respective limiting parts, and the support part 210 is released from the restraint, causing its contracted structure to gradually expand. Eventually, both the upper and lower parts of the support part 210 are in a ring-like structure, and the overall is in a cylindrical structure. It can be seen that in this embodiment, by using a degradable material for the restraint ring 100, the support device 200 is restrained and the restraint is cancelled at different stages, thereby realizing the morphological conversion of the support device 200.

[0047] When the restraint ring 100 has not degraded and the support device 200 is in an umbrella-like structure, it has the following characteristics: (1) The symmetric brackets of the umbrella shape have uniform opening sizes, and the thrombus capture effect is stable. It can ensure that thrombi of a certain size cannot pass through, and allows smaller non-fatal thrombi to pass through, and it is not easy to cause excessive thrombus accumulation.

[0048] (2) It has a relatively large capture volume, and has a relatively small impact on the reduction of the blood passage area of the blood vessel after capturing a thrombus. The thrombus has a tendency to deposit and accumulate in the middle, and it also avoids a relatively common type of embolism that spreads from the blood vessel wall along the struts to the filter.

[0049] (3) Considering from the perspective of hemodynamics, the shear stress on the thrombus in the central part itself is relatively large, and capturing the thrombus in the center is beneficial to the self-dissolution process of the thrombus. If it is near the blood vessel wall, it is easy to form a thrombus.

[0050] (4) The recovery time window is long.

[0051] However, the umbrella-like structure has the following disadvantages: it is prone to tilt after release. After the filter topples, the recovery hook 213 will stick to the wall, and then the capturer cannot catch the recovery hook 213, resulting in a recovery failure.

[0052] When the restraint ring 100 degrades and the support device 200 is in a cylindrical structure, it has the following characteristics: After the degradable restraint ring 100 degrades and loses its mechanical properties, the restraint is released, and the non-degradable main body of the support device 200 bounces off and adheres to the wall, transforming into a cylindrical structure and remaining in the body. The formed cylindrical structure can avoid the problem that the long-term indwelling of the filter hinders blood flow, and it is not easy to topple, which is convenient for recovery or retention in the body.

[0053] Before the implanting of the convertible inferior vena cava filter, due to the restraint of the restraint ring 100, the whole support device 200 maintains an umbrella structure and has the above advantages; in the later stage of implantation, since the restraint ring 100 degrades, the whole support device 200 presents a cylindrical structure and has the above advantages. Through the restraint ring 100, the morphology conversion of the inferior vena cava filter is realized, and at the same time, the advantages of both the umbrella structure and the cylindrical structure are possessed.

[0054] It should be understood that the degradable material can be materials such as magnesium alloy, zinc alloy, and iron alloy; the non-degradable material can adopt materials such as nickel-titanium alloy, stainless steel, cobalt-based alloy material, and polytetrafluoroethylene. The superelastic material nickel-titanium alloy is preferably considered, and its shape can be fixed by heat treatment to ensure that it automatically returns to its original shape after the restraint is removed.

[0055] The support device 200 further includes a recovery hook 213, which is arranged at one end of the support part 210. The recovery hook 213 is made of non-degradable material, and the whole support device 200 can be taken out by using the recovery hook 213, which is convenient for recovery.

[0056] A convertible inferior vena cava filter provided by the present invention includes: a support device 200 and a restraint ring 100. The support device 200 includes a plurality of support parts 210 and a recovery hook 213. One end of the support part 210 can be limited by the restraint ring 100 to form a contracted structure, and the other end of the support part 210 forms an expanded structure. The recovery hook 213 is arranged at least at one end of one of the support parts 210; the restraint ring 100 is made of degradable material, and the restraint ring 100 is a rigid structure before degradation. The restraint ring 100 includes a plurality of limiting parts and a plurality of connecting parts. The plurality of limiting parts are arranged along the circumferential direction of the restraint ring 100, and adjacent two limiting parts are connected by a connecting part. The limiting parts are used to limit and restrain the support part 210. For the convertible inferior vena cava filter provided by the present invention, under the restraint and limitation of the restraint ring 100, the whole support device 200 initially presents an umbrella structure, and the thrombus capture effect is stable; in the later stage, since the restraint ring 100 is made of degradable material, after its degradation, the restraint fails, and the support device 200 self-expands and returns to the cylindrical structure, which can avoid the problem that the long-term indwelling of the filter hinders blood flow; the whole support device can be taken out by using the recovery hook 213, which is convenient for recovery. It can be seen that for the convertible inferior vena cava filter provided by the present invention, through the degradable restraint ring 100, when it is not degraded, it provides a restraint effect, and the support device 200 is in an umbrella shape. The connecting part degrades prior to the limiting part. After the connecting part degrades, the support part 210 pops open and supports on the blood vessel wall, and the limiting part is fixed on the blood vessel wall along with the support part 210. Endothelial cells crawl on the degradable material, thereby reducing the risk of shedding of the degradable material. On the one hand, it overcomes the problem of difficult recovery existing in the umbrella structure and the lantern structure in the prior art, and at the same time has the advantages of both the umbrella structure and the cylindrical structure. On the other hand, it avoids the problem of pulmonary embolism caused by the shedding of the degradable material.

[0057] In one embodiment of the present invention, the connecting portion is a first groove 101 formed on the inner wall and / or the outer wall of the restraint ring 100, and the thickness of the first groove 101 is smaller than that of the limiting portion. In this embodiment, by processing the first groove 101 on the inner wall and / or the outer wall of the restraint ring 100, its thickness is reduced and ensured to be smaller than that of the limiting portion. Therefore, the connecting portion degrades completely prior to the limiting portion. In the following several embodiments, regardless of whether the limiting portion is in the form of a groove or a through-hole, the thickness of the first groove 101 is smaller than the thickness of the limiting portion for limiting the restraint support portion 210.

[0058] In one embodiment of the present invention, the depth direction of the first groove 101 is arranged parallel to the radial direction of the restraint ring 100, and a plurality of limiting portions are connected and combined in a ring shape, and a plurality of first grooves 101 are arranged in a ring shape. When the first groove 101 fails due to degradation, the respective limiting portions still remain on the support portion 210 and bounce outward with the support portion 210.

[0059] In one embodiment of the present invention, as Figure 1 and Figure 12 shown, the support portion 210 includes: a support rod 211 and a fixing hook 212. The support rod 211 is made of non-degradable material; the fixing hook 212 is correspondingly arranged at one end of the support rod 211 and is made of degradable material; the recovery hook 213 is arranged at least at the other end of the support rod 211 of one of the support portions 210. Specifically, each support portion 210 is composed of at least two parts, namely the support rod 211 and the fixing hook 212, and at least one support rod 211 among all the support portions 210 is provided with the recovery hook 213. The support rod 211 can be one-piece or multi-piece. The one-piece support rod 211 is as Figure 1 and Figure 2 shown, and the multi-piece type, such as the two-piece support rod 211, is sequentially connected to form a double-umbrella structure as Figure 3 shown. The support rod 211 and the recovery hook 213 are both made of non-degradable material, and the fixing hook 212 is made of degradable material. Moreover, the fixing hook 212 degrades later than the restraint ring 100. When the restraint ring 100 is completely degraded, the fixing hook 212 has not been completely degraded yet. The entire support device 200 can be taken out by using the recovery hook 213.

[0060] Furthermore, the support rod 211 can be made of tubular material by laser cutting; it can also be made of filamentous material by bending and fixing. The support device 200 is provided with a plurality of support rods 211 for filtering thrombus. The support rod 211 can be straight or curved; one end of the support rod 211 fixed to the restraint ring 100 is free, which is convenient for fixing with the restraint ring 100, and the processing technology is simple.

[0061] Embodiment 1: As Figure 4 and Figure 5 shown, in this embodiment, the limiting portion is a second groove 102 formed on the inner wall of the constraint ring 100, and one end of the support portion 210 is embedded in the second groove 102. The limiting and constraining of the support portion 210 is achieved through the second groove 102. Of course, in order to ensure that the connecting portion degrades prior to the limiting portion, it is only necessary to ensure that the thickness of the first groove 101 is less than that of the second groove 102. The first groove 101 degrades first, and the second groove 102 degrades later. It can be understood that the second groove 102 achieves the limiting and constraining of the support portion 210 through an interference fit method.

[0062] Specifically, since the constraint ring 100 is a ring structure, the support portion 210 can be clamped by the part of the second groove 102 close to the center of the constraint ring 100, thereby achieving its function of limiting and constraining.

[0063] The number of the second grooves 102 is the same as that of the support portions 210, and the support portions 210 are respectively and correspondingly embedded in the second grooves 102, so that one end of the support device 200 is constrained to form a necked-down structure.

[0064] In this embodiment, the second groove 102 is preferably a trapezoidal groove, which is matched and fixed with the support rod 211 to clamp the support portion 210. The thickness of the connecting section (i.e., the first groove 101) between the trapezoidal grooves on the degradable constraint ring 100 is less than that of the second groove 102. Under the same conditions, it degrades first. After losing its mechanical properties, the support rod 211 bounces outward, and the remaining limiting portion degrades after the support arm adheres to the wall.

[0065] Further, in order to better ensure the positioning and cooperation between the support rod 211 and the second groove 102, positioning grooves 2111 are machined on the front and rear sides of one end of the support rod 211. The positioning grooves 2111 are matched with the second groove 102, and during the assembly process, the positioning grooves 2111 can be quickly positioned and engaged with the second groove 102.

[0066] Embodiment 2: In this embodiment, the limiting portion is a first through hole 103 formed on the side wall of the constraint ring 100, and one end of the support portion 210 forms a first bending portion 2112, and the first bending portion 2112 is inserted and limited in the first through hole 103.

[0067] Specifically, by inserting the first bending portion 2112 into the first through hole 103 to form a snap connection with the first through hole 103, the function of limiting and constraining is achieved. In a structure as Figure 6 and Figure 7 shown, the first bending portion 2112 extends along the radial direction of the support rod 211, and after passing through the first through hole 103, one end of the support rod 211 is constrained and limited on the constraint ring 100.

[0068] Specifically, the supporting portion 210 is attached to the inner side of the restraining ring 100, and the first bent portion 2112 is inserted from the inner side of the restraining ring 100 and extends to the outer side of the restraining ring 100. That is to say, the restraining ring 100 is sleeved on the outer side of the support rod 211 to restrain and position it, and only the first bent portion 2112 needs to pass through the first through hole 103.

[0069] According to Figure 6 and Figure 7 the structure shown, the first bent portion 2112 is composed of two parts, a horizontal section and a vertical section. The horizontal section extends radially outward along the support rod 211, and the vertical section extends axially downward along the support rod 211 from the horizontal section; and, for the convenience of assembly and processing, the horizontal section is a radially contracting structure from the end close to the vertical section to the end far from the vertical section, that is, the radial dimension of the end of the horizontal section becomes smaller and smaller, forming a needle-like structure.

[0070] Embodiment 3: The structure of this embodiment is similar to that of the embodiment, and only the differences from Embodiment 2 are pointed out: In this embodiment, as Figure 8 and Figure 9 shown, the supporting portion 210 is attached to the outer side of the restraining ring 100, and the first bent portion 2112 is inserted from the outer side of the restraining ring 100 and extends to the inner side of the restraining ring 100. That is to say, the support rod 211 is arranged on the outer side of the restraining ring 100, and the first bent portion 2112 is inserted from the outer side to the inner side of the support rod 211.

[0071] The first bent portion 2112 is also composed of two parts, a horizontal section and a vertical section. It is indicated that the horizontal section extends radially inward along the support rod 211, and the others are the same or similar to the arrangement in Embodiment 2, and will not be elaborated here.

[0072] Embodiment 4: In this embodiment, as Figure 10 and Figure 11 shown, the limiting portion includes a second through hole 104 formed in the upper end wall of the restraining ring 100 and a third through hole 105 in the lower end wall of the restraining ring 100. One end of the supporting portion 210 forms a second bent portion 2113, and one end of the supporting portion 210 passes through the third through hole 105 and limits the second bent portion 2113 in the second through hole 104.

[0073] Specifically, the limiting part in this embodiment is different from the cylindrical structures in Embodiments 1 to 3. Its overall structure is a lantern shape, formed by combining an upper end wall, side walls, and a lower end wall. The upper end wall and the lower end wall are respectively inclinedly connected to the upper and lower ends of the side walls. A second through hole 104 is formed in the upper end wall, and a third through hole 105 is formed in the lower end wall. During the assembly process, one end of the support rod 211 sequentially passes through the third through hole 105 and the second through hole 104. The third through hole 105 can limit the support rod 211, and the second through hole 104 engages with the second bent portion 2113 to achieve the restraint and limitation of the support rod 211.

[0074] In this embodiment, each support rod 211 is limited twice through two through holes, namely the third through hole 105 and the second through hole 104. By means of two-point limitation, the support rod 211 is ensured to be vertical, avoiding tipping and skewing. In addition, the second bent portion 2113 is a movable trapezoidal surface, and the horizontal dimension of the trapezoidal surface is larger than its vertical dimension. When passing through the second through hole 104, the trapezoidal surface can be bent manually or by machining to make it pass through the second through hole 104. After that, after resetting the trapezoidal surface, its restraint and limitation of the support rod 211 are achieved.

[0075] It should be understood that the above-mentioned assembly process of each part can be to assemble after producing the independent support rod 211, recovery hook 213, fixing hook 212, and restraint ring 100, or directly machining the recovery hook 213, fixing hook 212, and restraint ring 100 on the support rod 211.

[0076] Embodiment 5: As Figure 13 shown, the connecting part in this embodiment includes: a first restraint line 106. The limiting part includes: a second restraint line 107 and a thickening sleeve 108. Among them, the second restraint line 107 is connected end to end with the first restraint line 106 to form a restraint sleeve ring, and the restraint sleeve ring is sleeved on two adjacent support parts 210; the thickening sleeve 108 is sleeved on the support part 210 along the thickness direction of the second restraint line 107 and is fixedly connected with the second restraint line 107. In this embodiment, both the connecting part and the limiting part adopt the structure of restraint lines. The first restraint line 106 and the second restraint line 107 are connected end to end to form a closed sleeve ring structure, which is sleeved between two adjacent support parts 210, and the thickening sleeve 108 is fixed along the thickness direction of the second restraint line 107.

[0077] It can be understood that the first restraint line 106, the second restraint line 107, and the thickening sleeve 108 are all made of biodegradable materials. The function of the thickening sleeve 108 is to thicken the thickness of the second restraint line 107. And since the thickening sleeve 108 is sleeved on the support part 210 and fixedly connected with the second restraint line 107, it also has the function of fixing the second restraint line 107 on the support part 210.

[0078] The second restraint line 107 is wound around the end of the support portion 210, and the second restraint lines 107 wound around two adjacent support portions 210 are connected by the first restraint line 106. Since the first restraint line 106, the second restraint line 107, and the thickening sleeve 108 are all made of degradable materials and undergo degradation simultaneously, when the first restraint line 106 degrades and fails, the support portion 210 pops open and fits against the inner side of the blood vessel wall. However, due to the thickening effect of the thickening sleeve 108 on the second restraint line 107, the thickening sleeve 108 and the second restraint line 107 do not completely fall off and still remain sleeved on the support portion 210. Moreover, the thickening sleeve 108 fixes the second restraint line 107 on the support portion 210, preventing it from falling off and causing the problem of pulmonary embolism.

[0079] As Figure 14 shown, the present invention also provides a convertible vena cava filter assembly, which includes: a plurality of convertible vena cava filters in the embodiments of the present invention, and adjacent convertible vena cava filters are connected by their respective support devices 200.

[0080] Specifically, two convertible vena cava filters can be connected at one end of the expansion structure through a support rod 211, thereby forming a connection layout of a double vena cava filter.

[0081] The convertible vena cava filter assembly provided by the present invention includes a plurality of convertible vena cava filters in the embodiments of the present invention. Therefore, it has the same advantages as above.

[0082] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art can understand and implement it without creative labor.

[0083] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A switchable vena cava filter, characterized in that: include: A support device (200) and a restraining ring (100); The support device (200) comprises a plurality of support parts (210) and a recovery hook (213); one end of the support part (210) can be limited by the constraint ring (100) to form a contraction structure, and the other end of the support part (210) forms an expansion structure; the recovery hook (213) is at least arranged at one end of one of the support parts (210); The constraint ring (100) is made of a degradable material and is a rigid structure before degradation. The constraint ring (100) comprises a plurality of limiting portions and a plurality of connecting portions. The plurality of limiting portions are arranged along the circumferential direction of the constraint ring (100), and two adjacent limiting portions are connected via a connecting portion. The limiting portion is fixed to one end of the support portion (210) and is used to limit and constrain the support portion (210). The connecting portion is configured to be degraded prior to the limiting portion; When the connection portion degrades and fails, the limiting portion expands along with one end of the supporting portion (210) and is supported on the blood vessel wall.

2. The switchable vena cava filter according to claim 1, characterized in that: The connecting portion is a first groove (101) formed on the inner wall of the restraint ring (100) and / or the outer wall of the restraint ring (100), and the thickness of the first groove (101) is smaller than that of the limiting portion.

3. The switchable vena cava filter according to claim 2, characterized in that: The depth direction of the first groove (101) is arranged parallel to the radial direction of the confinement ring (100).

4. The switchable vena cava filter according to any one of claims 1 to 3, characterized in that: The limiting portion is a second groove (102) formed on the inner wall of the restraining ring (100), and one end of the supporting portion (210) is embedded in the second groove (102).

5. The switchable vena cava filter according to any one of claims 1 to 3, characterized in that: The limiting portion is a first through hole (103) formed on the side wall of the restraining ring (100), and one end of the supporting portion (210) forms a first bent portion (2112), and the first bent portion (2112) is inserted into and limited in the first through hole (103).

6. The switchable vena cava filter according to claim 5, characterized in that: The support portion (210) is fitted onto the inner side of the restraint ring (100), and the first bent portion (2112) is inserted from the inner side of the restraint ring (100) and extends to the outer side of the restraint ring (100); or, the support portion (210) is fitted onto the outer side of the restraint ring (100), and the first bent portion (2112) is inserted from the outer side of the restraint ring (100) and extends to the inner side of the restraint ring (100).

7. The switchable vena cava filter according to any one of claims 1 to 3, characterized in that: The limiting portion comprises a second through hole (104) formed on the upper end wall of the restraining ring (100) and a third through hole (105) formed on the lower end wall of the restraining ring (100); a second bending portion (2113) is formed at one end of the supporting portion (210); one end of the supporting portion (210) passes through the third through hole (105) and limits the second bending portion (2113) in the second through hole (104).

8. The switchable vena cava filter according to claim 1, characterized in that: The connecting portion comprises: a first restraining line (106); The limiting part comprises: A second restraining line (107), the second restraining line (107) being connected end to end with the first restraining line (106) to form a restraining ring, the restraining ring being sleeved on two adjacent support portions (210); The thickened sleeve (108) is sleeved on the support portion (210) along the thickness direction of the second restraining line (107) and is fixedly connected to the second restraining line (107).

9. The switchable vena cava filter according to claim 1, characterized in that: The support portion (210) comprises: a support rod (211) and a fixing hook (212); The support rod (211) is made of a non-degradable material; The fixing hook (212) is arranged at one end of the supporting rod (211) and is made of a degradable material; The recovery hook (213) is arranged at least at the other end of the support rod (211) of one of the support parts (210).

10. A switchable vena cava filter assembly, characterized in that: include: The switchable vena cava filter according to any one of claims 1 to 9, wherein adjacent switchable vena cava filters are connected via the supporting device (200) to each other.

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