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, a constraint line and a constraint piece, the restraint line is made of a non-degradable material, and the restraint piece is made of a degradable material so as to restrain the restraint line to form an annular structure; the supporting device comprises a plurality of supporting parts, one end of each supporting part can be limited by a constraint line to form a contraction structure, and the other end of each supporting part forms an expansion structure; and the constraint line is fixedly connected with the supporting part. According to the convertible vena cava filter provided by the invention, the restraint part provides a restraint effect for the restraint line, so that the supporting device is of an umbrella-shaped structure, after the restraint part is degraded and the restraint line loses efficacy, the supporting part is bounced off and is supported on a blood vessel wall, and the restraint line is fixed on the supporting part, so that the problem of pulmonary embolism caused by falling of the restraint line is avoided; the problem that an umbrella-shaped structure and a lantern-shaped structure are difficult to recycle is solved, and the advantages of the umbrella-shaped structure and the barrel-shaped structure are achieved at the same time.

Description

Technical Field

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

[0002] An inferior vena cava filter (full English 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. The umbrella-shaped filter is prone to tilt after release. After the filter topples, the retrieval hook will stick to the wall, resulting in the capture device being unable to catch the retrieval hook and retrieval failure. The lantern-shaped filter has a certain anti-tilting ability after release. However, because the contact area between the filter and the blood vessel wall is large, endothelial cell growth will occur on the filter after 2-3 weeks generally. Theoretically, within 2 weeks is the best retrieval time, but many patients cannot retrieve 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 retrieval will cause venous injury / rupture, and even retrieval 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 retrieval 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, a restraint wire, and a restraint member; The restraint wire is made of a non-degradable material, and the restraint member is made of a degradable material and is fixed at both ends of the restraint wire to restrain the restraint wire to form a ring structure; The support device includes a plurality of support parts. One end of the support part can be limited by the restraint wire to form a contraction structure, and the other end of the support part forms an expansion structure; At least a part of the restraint wire except for both ends is fixedly connected to any one of the support parts.

[0006] The convertible vena cava filter provided by the present invention further includes: a plurality of connecting blocks, each of the connecting blocks is fixed at one end of the supporting part, the plurality of connecting blocks are in a fan-shaped block structure, and two sides of the plurality of connecting blocks along the circumferential direction extend radially from the axis; And when the supporting part forms a contraction structure, the plurality of connecting blocks surround and are spliced into an annular structure.

[0007] For the convertible vena cava filter provided by the present invention, the restraining member includes a pin made of a biodegradable material, pin holes are respectively formed at both ends of the restraining wire, and the pin is inserted into the pin holes to restrain the restraining wire to form an annular structure.

[0008] For the convertible vena cava filter provided by the present invention, threading rings are formed on the inner wall of the supporting part, and the threading rings on the plurality of supporting parts surround to form an annular structure, and the restraining wire sequentially passes through the threading rings.

[0009] For the convertible vena cava filter provided by the present invention, the threading ring includes: a first threading ring and a second threading ring, the first threading ring and the second threading ring are sequentially arranged along the height direction of the supporting part, and the first threading ring and the second threading ring are alternately arranged in the circumferential direction.

[0010] For the convertible vena cava filter provided by the present invention, a limiting groove is formed on the connecting block, and the restraining wire is arranged in the limiting groove; an assembly groove is formed in at least one of the limiting grooves on the plurality of connecting blocks, and the pin is limited in the assembly groove.

[0011] For the convertible vena cava filter provided by the present invention, the limiting groove includes a first limiting groove arranged on the outer wall of the connecting block.

[0012] For the convertible vena cava filter provided by the present invention, the connecting blocks are arranged at least in two layers along the height direction of the supporting part, the limiting groove includes a second limiting groove arranged on the inner wall of the connecting block, and the second limiting grooves on the multi-layer connecting blocks are alternately arranged in the circumferential direction.

[0013] For the convertible vena cava filter provided by the present invention, the supporting part includes: A support rod, made of a non-degradable material; A fixing hook, correspondingly arranged at one end of the support rod and made of a biodegradable material; A recovery hook, arranged at the other end of the support rod of at least one of the supporting parts.

[0014] 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 to each other through the respective supporting devices.

[0015] A convertible vena cava filter provided by the present invention comprises: a supporting device, a restraining wire and a restraining member. The restraining wire is made of a non-degradable material, and the restraining member is made of a degradable material and is fixed at both ends of the restraining wire to restrain the restraining wire to form an annular structure; the supporting device comprises a plurality of supporting parts, one end of the supporting part can be limited by the restraining wire to form a contracted structure, and the other end of the supporting part forms an expanded structure; at least a part of the restraining wire except both ends is fixedly connected to any one of the supporting parts. For the convertible vena cava filter provided by the present invention, before the restraining member degrades and fails, the restraining wire is restrained into an annular structure. Under the restraint and limitation of the restraining wire, the supporting device is initially in an umbrella-shaped structure as a whole, and the thrombus capture effect is stable; later, since the restraining member is made of a degradable material, after it degrades, the restraint fails, and the supporting 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. It can be seen that for the convertible vena cava filter provided by the present invention, the degradable restraining member provides a restraining effect on the restraining wire before degradation, so that the supporting device is in an umbrella-shaped structure. After the restraining member degrades, the restraining wire loses the restraining effect on the supporting part, the supporting part bounces open and supports on the blood vessel wall, and the restraining wire is fixed on the supporting part to avoid the risk of its falling off. On the one hand, the problem of difficult recovery existing in the umbrella-shaped structure and the lantern-shaped structure in the prior art is overcome, and at the same time, the advantages of both the umbrella-shaped structure and the cylindrical structure are possessed. On the other hand, the problem of pulmonary embolism caused by the falling off of the restraining wire is avoided.

[0016] 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

[0017] 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, other drawings can be obtained based on these drawings without creative efforts.

[0018] Figure 1 It is a schematic diagram of the overall structure of the convertible vena cava filter provided in the embodiment of the present invention when it is in the umbrella-shaped structure.

[0019] Figure 2 It is a schematic diagram of the overall structure of the convertible vena cava filter provided in the embodiment of the present invention when it is in the cylindrical structure.

[0020] 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 embodiment of the present invention.

[0021] Figure 4 It is a schematic diagram of the structure of the support part, the first threading loop, the second threading loop, the restraint wire and the restraint member in Embodiment 1 of the present invention.

[0022] Figure 5 It is a schematic diagram of the structure of the support part, the first threading loop and the connecting block in Embodiment 1 of the present invention.

[0023] Figure 6 It is a schematic diagram of the structure of the support part, the first limiting groove, the assembly groove, the restraint wire and the restraint member in Embodiment 2 of the present invention.

[0024] Figure 7 It is a schematic diagram of the partial structure of the first limiting groove, the assembly groove, the restraint wire and the restraint member in Embodiment 2 of the present invention.

[0025] Figure 8 It is a schematic diagram of the structure of the support part, the second limiting groove, the assembly groove and the restraint wire in Embodiment 3 of the present invention.

[0026] Figure 9 It is a schematic diagram of the structure of the support part, the second limiting groove, the assembly groove, the restraint wire and the restraint member in Embodiment 3 of the present invention.

[0027] Figure 10 It is Figure 1 a partial structure schematic diagram of A in

[0028] Figure 11 It is a schematic diagram of the structure of the convertible vena cava filter assembly provided in the embodiment of the present invention.

[0029] Reference signs: 100: restraint wire; 101: restraint member; 200: support device; 210: support part; 211: support rod; 212: fixing hook; 213: retrieval hook; 214: connecting block; 2151: first threading loop; 2152: second threading loop; 216: first limiting groove; 217: assembly groove; 218: second limiting groove. Detailed implementation manners

[0030] 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 with reference to the accompanying drawings in the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without making creative efforts fall within the scope of protection of the present invention.

[0031] In the description of this embodiment, it should be understood that the orientation or positional relationship indicated by the terms "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 drawings. It is only for the convenience of describing this embodiment 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. Therefore, it should not be construed as a limitation to this embodiment.

[0032] 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 specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of these features. In the description of this embodiment, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0033] In this embodiment, unless otherwise clearly specified and limited, the terms "set", "install", "connect", "join", "fix", 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 it 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 embodiment can be understood according to specific circumstances.

[0034] In the embodiments of the present invention, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature can be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0035] The following will be combined with Figures 1-10 Describe a convertible vena cava filter of the present invention. It includes: a support device 200, a restraint wire 100, and a restraint member 101.

[0036] Among them, the restraint line 100 is made of non-degradable material, and the restraint member 101 is made of degradable material and is fixed at both ends of the restraint line 100 to restrain the restraint line 100 to form an annular structure; the support device 200 includes a plurality of support portions 210, and one end of the support portion 210 can be limited by the restraint line 100 to form a contraction structure, and the other end of the support portion 210 forms an expansion structure; at least a part of the restraint line 100 except for both ends is fixedly connected to any one of the support portions 210.

[0037] Specifically, the support device 200 is supported on the inner wall of the blood vessel. A circular structure is formed by connecting a plurality of support portions 210. The upper end (or lower end) of the support portion 210 is restricted by the restraint line 100, so that the upper ends (or lower ends) of the plurality of support portions 210 form a contraction structure, and the other ends form an expansion structure. That is to say, the outer diameter of the circular structure formed by the support device 200 at one end is smaller than the outer diameter of the circular structure formed at the other end. Under the limit restraint of the restraint line 100, the support device 200 is in an umbrella-shaped structure as a whole.

[0038] The restraint line 100 forms an annular structure under the restraint of the restraint member 101. The restraint member 101 is made of degradable material, and the restraint line 100 is made of non-degradable material. When the restraint member 101 has not degraded, it exerts a restraint effect on the restraint line 100, making the restraint line 100 form an annular structure and restraining the upper end (or lower end) of the support portion 210 to form an annular structure; when the restraint member 101 degrades and fails, the restraint line 100 bounces off and loses the restraint effect on the support portion 210, and the support portion 210 immediately bounces and expands and supports on the blood vessel wall. Since at least a part of the restraint line 100 except for both ends is fixedly connected to one of the support portions 210, even after the restraint line 100 loses its restraint effect, it will not fall off, avoiding the problem of pulmonary embolism caused by the fall of the restraint line 100. Along with the bounce of the support portion 210, it adheres to the blood vessel wall. After that, the whole convertible inferior vena cava filter can be taken out. The limiting portion also adheres to the blood vessel wall as the support portion 210 bounces, and 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.

[0039] Regarding the materials of the support device 200, the restraint line 100 and the restraint member 101: 1. The main structure of the support 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, but the fixing hook 212 should lag behind the degradation of the restraint member 101 to ensure that the restraint member 101 degrades first, and then the fixing hook 212 degrades. The method that can be adopted is to increase the size of the fixing hook 212, so that under the same degradation speed, the fixing hook 212 degrades later.

[0040] 2. The restraining wire 100 is made of non-degradable material, but its restraining effect only takes effect before the restraint member 101 degrades and fails.

[0041] Of course, the restraint member 101 can be entirely made of degradable material or partially made of degradable material. If it is partially made of degradable material, it is necessary to ensure that the part connecting the two ends of the restraining wire 100 is made of degradable material, and other parts such as those playing the positioning role of the restraint member 101 can use non-degradable material.

[0042] Since the restraint member 101 in this embodiment is made of degradable material, before the restraint member 101 degrades and fails, the restraining wire 100 provides a restraining and limiting effect for the support device 200, making the overall support device 200 in an umbrella-shaped structure. When the restraint member 101 degrades and fails, the restraining wire 100 bounces off and releases its restraint effect, 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-shaped structure, and the overall is in a cylindrical structure. It can be seen that in this embodiment, by making the restraint member 101 of degradable material, the restraining wire 100 is used to restrain and cancel the restraint on the support device 200 at different stages, thereby realizing the morphological conversion of the support device 200.

[0043] When the restraint member 101 has not degraded and the support device 200 is in an umbrella-shaped 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 allow smaller non-fatal thrombi to pass through, and it is not easy to cause excessive thrombus accumulation.

[0044] (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 thrombi. Thrombi tend 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 legs to the filter.

[0045] (3) Considering from the perspective of hemodynamics, the shear stress on the thrombi in the central part itself is relatively large, and capturing thrombi in the center is beneficial to the self-dissolution process of thrombi. If it is near the blood vessel wall, it is easy to form thrombi.

[0046] (4) The recovery time window is long.

[0047] However, the umbrella-shaped 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 recovery failure.

[0048] When the restraint member 101 degrades and the support device 200 is in a cylindrical structure, it has the following characteristics: After the constraint member 101 degrades, the constraint wire 100 simultaneously loses its mechanical constraint performance, the constraint on the support portion 210 is released, and the main body of the non-degradable support device 200 springs open and adheres to the wall, transforming into a cylindrical structure and remaining in the body. The formed cylindrical structure can prevent the filter from hindering blood flow during long-term indwelling, and is not easily toppled, facilitating the problems of recovery or retention in the body.

[0049] In the early stage of placing the convertible vena cava filter, due to the constraint effect of the constraint member 101 on the constraint wire 100, the overall support device 200 maintains an umbrella structure and has the above advantages; in the later stage of placement, due to the degradation of the constraint member 101, the constraint wire 100 loses its constraint effect, and the overall support device 200 is in a cylindrical structure and has the above advantages. Through the state change of the constraint member 101 and the constraint wire 100, the morphological conversion of the vena cava filter is realized, and at the same time, the advantages of both the umbrella structure and the cylindrical structure are possessed.

[0050] 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 constraint is removed.

[0051] A convertible vena cava filter provided by the present invention includes: a support device 200, a restraint wire 100, and a restraint member 101. The restraint wire 100 is made of a non-degradable material, and the restraint member 101 is made of a degradable material and is fixed at both ends of the restraint wire 100 to restrain the restraint wire 100 to form a ring structure; the support device 200 includes a plurality of support portions 210. One end of the support portion 210 can be limited by the restraint wire 100 to form a contracted structure, and the other end of the support portion 210 forms an expanded structure; at least a part of the restraint wire 100 except for both ends is fixedly connected to any one of the support portions 210. For the convertible vena cava filter provided by the present invention, before the restraint member 101 degrades and fails, the restraint wire 100 is restrained into a ring structure. Under the restraint and limitation of the restraint wire 100, the support device 200 is initially in an umbrella-shaped structure as a whole, and the thrombus capture effect is stable; later, since the restraint member 101 is made of a degradable material, after it degrades, the restraint fails, and the support device 200 self-expands and returns to a cylindrical structure, which can avoid the problem that the long-term indwelling of the filter hinders blood flow. It can be seen that for the convertible vena cava filter provided by the present invention, the degradable restraint member 101 provides a restraint effect on the restraint wire 100 when it has not degraded, so that the support device is in an umbrella-shaped structure. After the restraint member 101 degrades, the restraint wire 100 loses the restraint effect on the support portion 210, and the support portion 210 bounces open and supports on the blood vessel wall. Moreover, the restraint wire 100 is fixed on the support portion 210 to avoid the risk of its detachment. On the one hand, it overcomes the problem of difficult retrieval existing in the umbrella-shaped structure and the lantern-shaped structure in the prior art, and at the same time 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 detachment of the restraint wire 100.

[0052] In one embodiment of the present invention, the convertible vena cava filter further includes: a plurality of connecting blocks 214. Each connecting block 214 is fixed at one end of the support portion 210. The plurality of connecting blocks 214 are in a fan-shaped block structure, and the two circumferential sides of the plurality of connecting blocks 214 extend radially from the axis. And when the support portion forms a contracted structure, the plurality of connecting blocks 214 surround and are spliced into a ring structure. Specifically, by machining and designing a connecting block 214 at one end of the contracted structure of the support portion, the connecting block 214 can be spliced into a ring structure in the contracted state, which can limit the shape of the support portion when it contracts. Before being sleeved with the restraint wire 100 for restraint, the support portion is quickly spliced into a ring structure through the connecting block 214, and then the restraint wire 100 is sleeved and the restraint member 101 is installed, which can ensure that the support portion is restrained into a ring structure. Optionally, the connecting block 214 is in an arc structure, and the plurality of connecting blocks 214 are spliced to form a ring structure.

[0053] In one embodiment of the present invention, the restraint member 101 includes a pin made of a biodegradable material. Pin holes are respectively formed at both ends of the restraint wire 100, and the pin is inserted into the pin holes to restrain the restraint wire 100 to form a ring structure. Specifically, pin holes are respectively formed at both ends of the restraint wire 100, and the biodegradable pin is inserted into the two pin holes to restrain the restraint wire 100 into a ring structure, thereby restraining the support portion 210.

[0054] In one embodiment of the present invention, as Figure 1 and Figure 10 shown, the support portion 210 includes: a support rod 211, a fixing hook 212, and a recovery hook 213. The support rod 211 is made of a non-biodegradable material; the fixing hook 212 is correspondingly arranged at one end of the support rod 211 and is made of a biodegradable 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 the recovery hook 213 is arranged on at least one support rod 211 among all the support portions 210. The support rod 211 can be a one-piece type or a multi-piece type. 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-biodegradable materials, and the fixing hook 212 is made of a biodegradable material. Moreover, the fixing hook 212 degrades later than the restraint member 101. When the restraint member 101 is completely degraded, the fixing hook 212 has not been completely degraded yet. The recovery hook 213 can be used to take out the entire support device 200.

[0055] Furthermore, the support rod 211 can be formed by laser cutting a tubular material; it can also be formed by bending and fixing a filamentous material. The support device 200 is provided with a plurality of support rods 211 for filtering blood clots. The support rods 211 can be straight or curved.

[0056] Regarding the restraint situation between the restraint wire 100 and the support portion 210, the present invention provides the following several embodiments for illustration.

[0057] Embodiment 1: As Figure 4 and Figure 5 shown, threading rings are formed on the inner wall of the support portion 210, and the threading rings on multiple support portions are surrounded to form a ring structure, and the restraint wire 100 sequentially passes through the threading rings.

[0058] Further, the wire threading loops include: a first wire threading loop 2151 and a second wire threading loop 2152. The first wire threading loop 2151 and the second wire threading loop 2152 are arranged in sequence along the height direction of the support portion, and the first wire threading loop 2151 and the second wire threading loop 2152 are alternately arranged in the circumferential direction.

[0059] Specifically, multiple constraint wires 100 can be adopted. In Figure 4 and Figure 5 In the illustrated embodiment, two constraint wires 100 are adopted to ensure stable constraint on the support portion 210. On this basis, the wire threading loops are also divided into a first wire threading loop 2151 and a second wire threading loop 2152 arranged along the height direction, and are alternately arranged in the circumferential direction. On the one hand, it ensures the stable constraint between the constraint wire 100 and the support portion 210, and on the other hand, it reduces the structural complexity.

[0060] Embodiment 2: A limiting groove is formed on the connecting block 214, and the constraint wire 100 is threaded through the limiting groove. An assembly groove 217 is formed in at least one of the limiting grooves on multiple connecting blocks 214, and a pin is limited in the assembly groove 217.

[0061] Further, the limiting groove includes a first limiting groove 216 provided on the outer wall of the connecting block 214.

[0062] Specifically, the assembly groove 217 has a lateral opening, which is beneficial to the degradation of the constraint member 101. The setting of the assembly groove 217 provides a positioning and installation position for the pin on the one hand, and on the other hand, during its degradation process, it ensures that it is located in the assembly groove 217 to avoid the problem of pulmonary embolism caused by the shedding of the degradable pin.

[0063] Optionally, in order to ensure that the pin is limited in the assembly groove 217, an inclined surface can be machined and designed in the assembly groove 217.

[0064] As Figure 6 and Figure 7 shown, the assembly groove 217 is located in the first limiting groove 216. The constraint wire 100 is sleeved in the first limiting groove 216, and after the pin is connected to the constraint wire 100, it is limited in the assembly groove 217. Optionally, through holes are machined and designed at the top and bottom of the assembly groove 217, and the pin can be vertically inserted downward from the through hole at the top of the assembly groove 217 into the assembly groove 217 to be connected to the pin hole and penetrate through to the through hole at the bottom, realizing the limitation of the pin and the constraint on the constraint wire 100.

[0065] Embodiment 3: This embodiment is similar in structure to Embodiment 2, with the only difference being the arrangement position of the limiting groove: In this embodiment, the connecting block 214 is provided with at least two layers along the height direction of the supporting portion 210. The limiting groove includes a second limiting groove 218 provided on the inner wall of the connecting block 214, and the second limiting groove 218 is alternately arranged in the circumferential direction on the multi-layer connecting blocks 214.

[0066] Preferably, two layers of second limiting grooves 218 are arranged in the height direction of the supporting portion 210, and two layers of constraint lines 100 are correspondingly configured. As Figure 8 and Figure 9 shown in the structure, two upper and lower layers of second limiting grooves 218 are arranged, and the two upper and lower layers of second limiting grooves 218 are alternately arranged in the circumferential direction of the supporting portion 210. Through holes for limiting the constraint line 100 are provided at positions where the second limiting groove 218 is not provided, and a constraint member 101 (i.e., a pin) is arranged inside the second limiting groove. By processing the size of the constraint member 101, the two upper and lower layers of constraint lines 100 are successively released from the constraint, so that the two upper and lower layers of connecting blocks 214 are elastically opened step by step. In addition to ensuring that the constraint line 100 is limited in the second limiting groove 218, the overall structural complexity is also reduced.

[0067] As Figure 11 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 through their respective supporting devices 200.

[0068] Specifically, two convertible vena cava filters can be connected at one end of the expansion structure through a support rod 211, so as to form a connection layout of a double vena cava filter.

[0069] 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.

[0070] 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.

[0071] 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 cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A switchable vena cava filter, characterized in that: include: A supporting device (200), a restraining line (100) and a restraining member (101); The restraining wire (100) is made of a non-degradable material, and the restraining member (101) is made of a degradable material and is fixed at both ends of the restraining wire (100) to restrain the restraining wire (100) to form a ring structure; The support device (200) comprises a plurality of support parts (210), one end of the support part (210) can be limited by the restraining line (100) to form a contraction structure, and the other end of the support part (210) forms an expansion structure; At least a portion of the restraining line (100) other than the two ends is fixedly connected to any one of the supporting parts (210).

2. The switchable vena cava filter according to claim 1, characterized in that: Also includes: A plurality of connection blocks (214), each of the connection blocks (214) being fixed to one end of the support portion (210), the plurality of connection blocks (214) being in a fan-shaped block structure, and the plurality of connection blocks (214) extending radially from the axis along two side edges in the circumferential direction; Furthermore, when the support portion forms a contraction structure, a plurality of the connection blocks (214) are surrounded and spliced ​​into a ring-shaped structure.

3. The switchable vena cava filter according to claim 2, characterized in that: The restraining member (101) comprises a pin made of a degradable material, and pin holes are respectively formed at both ends of the restraining line (100), and the pin is inserted into the pin holes to restrain the restraining line (100) to form a ring structure.

4. The switchable vena cava filter according to any one of claims 1 to 3, characterized in that: A threading ring is formed on the inner wall of the support portion (210), and a plurality of the threading rings on the support portion are arranged to form a ring structure, and the restraining wire (100) passes through the threading rings in sequence.

5. The switchable vena cava filter according to claim 4, characterized in that: The threading ring comprises: a first threading ring (2151) and a second threading ring (2152), wherein the first threading ring (2151) and the second threading ring (2152) are arranged in sequence along the height direction of the support portion, and the first threading ring (2151) and the second threading ring (2152) are alternately arranged in the circumferential direction.

6. The switchable vena cava filter according to claim 3, characterized in that: A limiting groove is formed on the connecting block (214), and the restraining line (100) is passed through the limiting groove; An assembly groove (217) is formed in at least one limiting groove on the plurality of connection blocks (214), and the pin is limitedly disposed in the assembly groove (217).

7. The switchable vena cava filter according to claim 6, characterized in that: The limiting groove comprises a first limiting groove (216) provided on the outer wall of the connecting block (214).

8. The switchable vena cava filter according to claim 6, characterized in that: The connection block (214) is provided with at least two layers along the height direction of the support portion (210); the limiting groove comprises a second limiting groove (218) provided on the inner wall of the connection block (214); and the second limiting groove (218) is alternately provided along the circumferential direction on the multiple layers of the connection block (214).

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