Vena cava filter

Abstract

The present invention provides a vena cava filter, which relates to the field of medical devices, including a support frame and a filter body; the filter body includes a fixed arm, an anchoring arm and a retrieval hook; the proximal end of the fixed arm and the proximal end of the anchoring arm are both connected to the opposite end of the hook end of the retrieval hook, and the distal end of the anchoring arm is provided with an anchoring portion, which is anchored to the inner side of the support frame; in the released state: the support frame is expanded into a cylindrical shape, and the distal ends of the fixed arm and the anchoring arm are opened to all sides, so that the fixed arm and the anchoring arm are expanded into an umbrella shape; the anchoring portion can be detached from the support frame when the retrieval hook is subjected to an external force dragging toward the proximal end. The present invention solves the problems in the prior art that the vena cava filter is prone to bleeding at the implantation site after being released into a blood vessel, the filter implantation time is short, and the filter is difficult to remove safely. At the same time, it can avoid the displacement of the filter after the vena cava filter is released into a blood vessel.

Description

Technical Field

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

[0002] Venous Thromboembolism (VTE) refers to the formation of blood plaques in the veins, most commonly in the deep veins of the lower extremities, which is called deep vein thrombosis. The embolus may break off from the site where it is generated and enter the blood circulation, a situation called embolism. VTE has many clinical manifestations. Venous thrombosis is generally asymptomatic, with occasional pain and lower extremity edema. Some emboli may enter the lungs, causing potentially fatal pulmonary embolism; symptomatic venous thrombosis often leads to a series of complications; chronic venous insufficiency can cause long-term symptoms, resulting in venous ulcers and changes in the limbs after embolism, manifested as chronic pain, swelling and skin changes, and severe cases can lead to pulmonary embolism.

[0003] Pulmonary embolism refers to a pathological process caused by the obstruction of the pulmonary artery or its branches by emboli. Its diagnosis rate is low, and the misdiagnosis rate and mortality rate are high. Some scholars believe that 80% to 90% of pulmonary embolism emboli come from lower extremity venous thrombosis, especially during thrombolytic therapy, the chance of emboli falling off is higher, and large emboli can cause death within a few minutes. It has been reported that the mortality rate of pulmonary embolism caused by iliofemoral vein thrombosis is as high as 20% to 30%. The typical symptoms of pulmonary embolism are dyspnea, chest pain, cough, and hemoptysis. The three major signs are pulmonary rales and hyperactive gallop rhythm of the second sound in the pulmonary valve area. Therefore, clinically, the prevention of pulmonary embolism is more important than treatment.

[0004] At present, the most common clinical method for preventing pulmonary embolism is to implant a vena cava filter into the inferior vena cava. The vena cava filter is a device made of metal wire that is placed into the vein under the kidney through a special delivery device to intercept larger blood clots in the blood flow and prevent them from entering the pulmonary artery with the blood flow and causing fatal pulmonary embolism.

[0005] The existing vena cava filter mainly includes a filter arm composed of a fixed arm and an anchoring arm, and a retrieval hook connected to the proximal end of the filter arm. The distal end of the anchoring arm is provided with an anchoring hook. The function of the retrieval hook is to capture the retrieval hook in the blood vessel through a retrieval device after the filter is implanted in the human body for a period of time, and then pull it out of the body to realize the recovery of the filter; the anchoring hook is a barb structure, and its function is to insert the barb of the filter into the venous vessel wall after the filter is released in the blood vessel to prevent the filter from shifting.

[0006] However, existing vena cava filters have at least the following problems:

[0007] Since veins are very thin, the anchor hook’s barbed anti-displacement structure can easily puncture or pierce the blood vessels, causing bleeding at the implant site, which causes significant damage to the blood vessels. At the same time, the barbed anti-displacement structure pierces the blood vessel wall, causing endothelial hyperplasia. The endothelial tissue will gradually cover the vena cava filter after a period of time, causing the filter and blood vessels to grow together, which will make it difficult to withdraw the filter from the blood vessel. The larger the contact area between the filter and the blood vessel tissue and the longer the contact time, the more difficult it will be to recover the filter from the blood vessel. If the recovery time is too short, the filter will only function for a short time in the blood vessel, which will far from achieve the desired therapeutic effect. In addition, because the anchor hook pierces the blood vessel wall, after the filter is withdrawn from the blood vessel, there will be a large wound at the original contact site, which will cause significant damage to the blood vessel and is also very likely to accumulate thrombi again.

[0008] In addition, after the vena cava filter is released into the blood vessel, the filter is prone to tilting, and the retrieval hook contacts the blood vessel wall, making it difficult for the retrieval hook to be captured by the retrieval device and difficult to retrieve. Although some vena cava filters use a large-angle bend at the position of the fixed arm close to the retrieval hook to contact the blood vessel wall to prevent tilting, it is found in actual use that this type of vena cava filter cannot completely avoid tilting, but only reduces the incidence of filter tilting, because when the filter is released, the filter anchor only contacts at a few points, and the blood will impact the filter. Under such complex conditions, it is also easy to cause the filter to tilt when released, resulting in problems such as difficulty in safely removing the filter from the blood vessel after completing its mission.

[0009] In summary, in the prior art, after the vena cava filter is released into the blood vessel, bleeding at the implantation site is prone to occur, the filter implantation time is short, and the filter is difficult to remove safely. Summary of the invention

[0010] The purpose of the present invention is to provide a vena cava filter to avoid displacement of the filter after the vena cava filter is released into the blood vessel, thereby solving the problems in the prior art that the vena cava filter is prone to bleeding at the implantation site, the filter implantation time is short, and the filter is difficult to remove safely after being released into the blood vessel.

[0011] To achieve the above objectives, the embodiments of the present invention adopt the following technical solutions:

[0012] An embodiment of the present invention provides a vena cava filter, comprising a support frame and a filter body; the filter body comprises a fixed arm, an anchoring arm and a retrieval hook; the proximal end of the fixed arm and the proximal end of the anchoring arm are both connected to the opposite ends of the hooking end of the retrieval hook, and the distal end of the anchoring arm is provided with an anchoring portion, and the anchoring portion is anchored to the inner side surface of the support frame; in a released state: the support frame is expanded into a cylindrical shape, and the distal ends of the fixed arm and the anchoring arm are opened to all sides, so that the fixed arm and the anchoring arm are expanded into an umbrella shape; the anchoring portion can be detached from the support frame when the retrieval hook is subjected to an external force dragging toward the proximal end.

[0013] In an optional embodiment, a developing portion is provided on the support frame, and a developing coating is coated on the anchoring arm.

[0014] In an optional embodiment, the support frame includes a bare stent and a coating connected to the bare stent; the anchoring portion is anchored to the bare stent or the coating.

[0015] In an optional embodiment, the distal end of the anchoring arm is provided with a curved portion that bends in an opening direction when released, and the curved portion constitutes the anchoring portion; a fixing device is connected to the inner side surface of the coating, and the fixing device fixes the curved portion to the inner side surface of the coating; the curved portion can be detached from the fixing device when the retrieval hook is subjected to an external force that drags proximally.

[0016] In an optional embodiment, the fixing member includes a developing ring and / or a suture, wherein "and / or" indicates that the fixing member may be a developing ring or a suture, or that the developing ring and the suture are used simultaneously in the fixing member to fix different bending parts respectively.

[0017] In an optional embodiment, the length of the anchoring arm is greater than the length of the fixing arm, and the anchoring portion is provided at a position where the distal end of the anchoring arm is longer than the fixing arm.

[0018] In an optional embodiment, the distal end surface of the fixing arm and the distal end surface of the anchoring arm are both arc surfaces.

[0019] In an optional embodiment, the bare stent includes a plurality of stent rings, and the plurality of stent rings are connected to the coating in pairs and arranged at intervals from the distal end of the coating to the proximal end of the coating.

[0020] In an optional embodiment, the support ring is formed by connecting a plurality of V-shaped support units end to end.

[0021] In an optional embodiment, the filter body further comprises a connecting sleeve; one end of the connecting sleeve is connected to the opposite end of the hooking end of the recovery hook, and the proximal end of the fixing arm and the proximal end of the anchoring arm are both connected to the connecting sleeve.

[0022] The embodiments of the present invention can achieve the following beneficial effects:

[0023] An embodiment of the present invention provides a vena cava filter, comprising a support frame and a filter body; the filter body comprises a fixed arm, an anchoring arm and a retrieval hook; the proximal end of the fixed arm and the proximal end of the anchoring arm are both connected to the opposite ends of the hooking end of the retrieval hook, and the distal end of the anchoring arm is provided with an anchoring portion, which is anchored to the inner side surface of the support frame; in the released state: the support frame is expanded into a cylindrical shape, and the distal ends of the fixed arm and the anchoring arm are opened to all sides, so that the fixed arm and the anchoring arm are expanded into an umbrella shape; the anchoring portion can be detached from the support frame when the retrieval hook is subjected to an external force dragging toward the proximal end.

[0024] The embodiments of the present invention avoid displacement of the vena cava filter after it is released into a blood vessel, thereby solving the problems in the prior art of bleeding at the implantation site, short filter implantation time, and difficulty in safely removing the filter after the vena cava filter is released into a blood vessel. The specific structure and functional effects achieved are shown in the specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 A schematic diagram of the overall structure of a support frame in a vena cava filter provided in an embodiment of the present invention;

[0027] Figure 2 A schematic diagram of the overall structure of a filter body in a vena cava filter provided in an embodiment of the present invention;

[0028] Figure 3 A schematic diagram of the overall structure of the vena cava filter in a released state provided by an embodiment of the present invention;

[0029] Figure 4 for Figure 3 A magnified view of the local structure of part A.

[0030] Icons: 1-support frame; 11-bare support; 111-support ring; 12-coating; 2-filter body; 21-fixing arm; 22-anchoring arm; 221-bend part; 23-recovery hook; 24-connecting sleeve; 3-developing ring. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0034] In the description of the present invention, it should be noted that the terms "proximal", "distal", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply 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 on the present invention.

[0035] Particularly, in the present invention, the term "proximal end" refers to an end closer to the human heart during surgery, and the "distal end" refers to the other end opposite to the "proximal end".

[0036] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "setting", "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] Some embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0038] This embodiment provides a vena cava filter, referring to Figures 1 to 4, the vena cava filter includes a support frame 1 and a filter body 2. Specifically, the filter body 2 includes a fixed arm 21, an anchoring arm 22 and a retrieval hook 23; the proximal end of the fixed arm 21 and the proximal end of the anchoring arm 22 are both connected to the opposite end of the hook end of the retrieval hook 23, and the distal end of the anchoring arm 22 is provided with an anchoring portion, and the anchoring portion is anchored to the inner side of the support frame 1. In the released state: the support frame 1 is opened to form a cylindrical shape, and the distal ends of the fixed arm 21 and the distal ends of the anchoring arm 22 are opened to the surroundings, so that the fixed arm 21 and the anchoring arm 22 are opened to form an umbrella shape; the anchoring portion can be separated from the support frame 1 when the retrieval hook 23 is subjected to an external force dragging toward the proximal end. In this embodiment, the specific number of the fixed arm 21 and the anchoring arm 22 is not specifically limited, and can include but is not limited to 10 fixed arms 21 and 2 anchoring arms 22.

[0039] Before thrombosis treatment: use the implantation device to implant the above-mentioned vena cava filter at the thrombus filtering position in the blood vessel, release the support frame 1 and the filter body 2, the support frame 1 is expanded into a cylindrical shape to support the inner wall of the blood vessel, and the fixed arm 21 and the anchoring arm 22 are expanded into an umbrella shape; then, the filter arm composed of the fixed arm 21 and the anchoring arm 22 of the filter body 2 is used to filter larger venous thrombi to prevent the occurrence of pulmonary embolism; after the treatment is completed, the filter body 2 is recovered from the blood vessel. Specifically, the filter body 2 is withdrawn in the proximal direction by dragging the recovery hook 23 toward the proximal end, so as to separate the filter body 2 containing the filtered thrombus from the support frame 1 and withdraw it outside the blood vessel, and the support frame 1 is permanently placed in the body.

[0040] In this embodiment, the anchoring portion of the filter body 2 is anchored to the inner side of the support frame 1, rather than directly anchored to the blood vessel wall. Thus, the vena cava filter provided in this embodiment can at least achieve the following beneficial effects:

[0041] (1) After release, the support frame 1 expands into a cylindrical shape to support the inner wall of the blood vessel, which has a good supporting and anti-displacement effect and can prevent the filter from shifting;

[0042] (2) The support frame 1 is expanded into a cylindrical shape. The implantation of the support frame 1 does not damage the blood vessels. After the vena cava filter is completely released, the filter body 2 does not directly contact the blood vessel wall, which can avoid stabbing or puncturing the blood vessel after the filter is implanted, thus solving the problem of bleeding at the implantation site after the vena cava filter is released into the blood vessel in the prior art;

[0043] (3) After the vena cava filter is completely released, the vascular endothelial proliferation process does not contact the filter body 2. After the filter body 2 has been implanted for a long time, it can still be pulled out of the support frame 1, thereby extending the removal time of the filter body 2. The recovery time is long enough, and the filter body 2 can filter large thrombi in the human body for a long time, solving the problem of short filter implantation time after the vena cava filter is released in the blood vessel in the prior art;

[0044] (4) After the vena cava filter is completely released, the blood vessel wall does not contact the filter body 2, so when the filter body 2 is withdrawn, the blood vessel will not be pulled, and the filter body 2 can be easily withdrawn, and the process of withdrawing the filter body 2 does not damage the blood vessel;

[0045] (5) After the vena cava filter is completely released, the contact area between the filter body 2 and the support frame 1 is large, and the fixed arm 21 and the anchoring arm 22 of the filter body 2 are supported on the support frame 1, thereby preventing the filter body 2 from tilting. In turn, it is beneficial for the filter body 2 to always maintain a filtering posture, and it is beneficial to capture the recovery hook 23 and withdraw the filter body 2. The process of withdrawing the filter body 2 does not damage the blood vessels.

[0046] In summary, this embodiment avoids displacement of the vena cava filter after it is released into a blood vessel, and solves the problems in the prior art that the vena cava filter is prone to bleeding at the implantation site, the filter implantation time is short, and the filter is difficult to remove safely after it is released into a blood vessel.

[0047] In order to accurately obtain the implantation position, in the present embodiment, a developing portion is provided on the support frame 1, and a developing coating is applied on the anchoring arm 22; wherein the developing portion preferably includes a distal developing portion, a middle developing portion and a proximal developing portion, which are respectively sewn or otherwise connected to the support frame 1, wherein the middle developing portion is preferably arranged at or near the pre-anchoring position of the anchoring portion 1, and the distal developing portion and the proximal developing portion are respectively correspondingly arranged at the position closest to the distal end of the support frame 1 and the position closest to the proximal end of the support frame 1, and the developing portion is used as a reference during the operation to ensure that the release position of the support frame 1 and the filter body 2 is accurate.

[0048] Reference Figures 1 to 4 In the optional implementation of this embodiment, it is more preferred that the support frame 1 includes a bare stent 11 and a coating 12 connected to the bare stent 11; the anchoring portion is anchored to the bare stent 11 or the coating 12, preferably, the distal end of the fixed arm 21 and the distal end of the anchoring arm 22 do not exceed the distal end of the coating 12, and after the vena cava filter is completely released, the distal end of the fixed arm 21 is stretched out to the outside or inside of the coating 12. Among them, the coating 12 can be connected to the inside of the bare stent 11 or to the outside of the bare stent 11. It is more preferred that the bare stent 11 is connected to the outside of the coating 12 to increase the anti-displacement function of the support frame 1 and at the same time improve the compliance of the bare stent 11. The specific connection method between the bare stent 11 and the coating 12 includes but is not limited to the following. Figures 1 to 4 As shown, the bare stent 11 is sewn to the coating 12. In this optional embodiment, the coating 12 can be a fabric coating or a polymer coating, etc., preferably but not limited to a polymer coating with better adaptability to the human body, so as to reduce or avoid the immune rejection reaction of the human body to the coating 12.

[0049] In the optional implementation manner of this embodiment, the specific structure of the anchoring portion has various types, including but not limited to a hook or barb structure that is bent in the direction of opening when released. In the released state, the distal end of the anchoring arm 22 is located inside the support frame 1, and the anchoring portion is anchored to the inner side of the support frame 1. Although the anchoring portion is a hook or barb structure, its anchoring position is located on the support frame 1, not the blood vessel wall, so that it will not cause damage to the blood vessel. The specific structure of the anchoring portion can also be other structures. Among them, among the multiple optional structures of the anchoring portion, it is more preferred that in the filter body 2, the distal end of the anchoring arm 22 is provided with a curved portion 221 that is bent in the direction of opening when released, and the curved portion 221 constitutes the anchoring portion; a fixing member is connected to the inner side of the coating 12, and the fixing member fixes the curved portion 221 to the inner side of the coating 12; the curved portion 221 can be detached from the fixing member when the retrieval hook 23 is subjected to an external force that drags toward the proximal end; the fixing member includes but is not limited to the following. Figure 4 The developing ring 3 or the stitching shown.

[0050] When the fixing part is a developing ring 3, specifically: the developing ring 3 can be but is not limited to being sewn on the inner side of the coating 12 by sutures, and the developing ring 3 is located in the groove of the curved portion 221, so that the curved portion 221 can be fixed to the inner side of the coating 12 by using the developing ring 3. After the vena cava filter is implanted into the blood vessel, the support frame 1 and the filter body 2 are released to filter the plug. When the filter body 2 needs to be withdrawn, the recovery hook 23 is dragged in the proximal direction with appropriate external force, so that the curved portion 221 can be pulled off the developing ring 3, thereby making the filter body 2 detached from the support frame 1. Further, the filter body 2 is withdrawn to the outside of the blood vessel.

[0051] When the fixing member is a suture, specifically: the curved portion 221 is sutured to the bare stent 11 and / or the coating 12 with the suture ends not fixed, and after the vena cava filter is implanted into the blood vessel, the support frame 1 and the filter body 2 are released to filter the thrombus, and when the filter body 2 needs to be withdrawn, the recovery hook 23 is dragged in the proximal direction with appropriate external force, so that the suture on the curved portion 221 can be pulled off the bare stent 11 and the coating 12, thereby separating the filter body 2 from the support frame 1, and further, the filter body 2 is withdrawn to the outside of the blood vessel.

[0052] In an optional implementation manner of the present embodiment, more preferably, at least one bend 221 is respectively provided at the distal end of each anchoring arm 22. To increase the anchoring stability and further prevent the filter body 2 from shifting or tilting, at least two bends 221 spaced apart from each other are preferably provided.

[0053] To facilitate anchoring, in an optional implementation of this embodiment, it is more preferred that the length of the anchoring arm 22 is greater than the length of the fixed arm 21, and the anchoring portion is provided at a position where the distal end of the anchoring arm 22 is longer than the fixed arm 21.

[0054] In addition, in order to prevent the fixing arm 21 and the anchoring arm 22 from scratching the blood vessels during the implantation or withdrawal process, in an optional implementation of the present embodiment, it is more preferred that the distal end surfaces of the fixing arm 21 and the anchoring arm 22 are both curved surfaces, preferably hemispherical surfaces.

[0055] In an optional implementation of this embodiment, preferably, the bare stent 11 includes a plurality of stent rings 111, and the plurality of stent rings 111 are arranged in pairs from the distal end of the coating 12 to the proximal end of the coating 12 and connected to the coating 12. The arrangement of the plurality of stent rings 111 increases the wall adhesion of the coating 12, which can prevent large thrombi from leaking from between the coating 12 and the blood vessel wall, thereby improving the effectiveness of thrombus filtering. To increase the supporting force of the stent ring 111, preferably, the stent ring 111 is formed by connecting a plurality of V-shaped stent units end to end.

[0056] In addition, in an optional implementation of the present embodiment, more preferably, the filter body 2 also includes a connecting sleeve 24; one end of the connecting sleeve 24 is connected to the opposite end of the hooking end of the recovery hook 23, and the proximal end of the fixed arm 21 and the proximal end of the anchoring arm 22 are both connected to the connecting sleeve 24. The connecting sleeve 24 can be but is not limited to a steel sleeve structure, and the opposite end of the hooking end of the recovery hook 23, the proximal end of the fixed arm 21 and the proximal end of the anchoring arm 22 are all welded to the connecting sleeve 24.

[0057] In this embodiment, the filter body 2 is preferably made entirely of steel or other metals.

[0058] Finally, it should be noted that: the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referenced to each other; the above embodiments in this specification are only used to illustrate the technical solution of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that: it is still possible to modify the technical solutions recorded in the aforementioned embodiments, or to replace some or all of the technical features therein with equivalents; and these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the present invention.

Claims

1. A vena cava filter, characterized in that: It comprises a support frame (1) and a filter body (2); The filter body (2) comprises a fixing arm (21), an anchoring arm (22) and a recovery hook (23); The proximal end of the fixing arm (21) and the proximal end of the anchoring arm (22) are both connected to the ends opposite to the hooking end of the retrieval hook (23); the distal end of the anchoring arm (22) is provided with a bent portion (221) bent in the direction of opening when released, the bent portion (221) constituting an anchoring portion, and the length of the anchoring arm (22) is greater than the length of the fixing arm (21), and the anchoring portion is provided at a portion of the distal end of the anchoring arm (22) that is longer than the fixing arm (21); The support frame (1) comprises a bare support frame (11) and a coating (12) connected to the bare support frame (11), and a fixing piece is connected to the inner side surface of the coating (12); the fixing piece fixes the curved portion (221) to the inner side surface of the coating (12); In the released state: the support frame (1) is expanded to form a cylindrical shape, and the distal ends of the fixing arms (21) and the anchoring arms (22) are opened in all directions, so that the fixing arms (21) and the anchoring arms (22) are expanded to form an umbrella shape; The bent portion (221) can be separated from the fixing member and then from the support frame (1) when the recovery hook (23) is subjected to an external force dragging toward the proximal end.

2. The vena cava filter according to claim 1, characterized in that: A developing portion is provided on the support frame (1), and a developing coating is coated on the anchoring arm (22).

3. The vena cava filter according to claim 1, characterized in that: The fixing element comprises a developing ring (3) and / or a suture.

4. The vena cava filter according to claim 1, characterized in that: The distal end surface of the fixing arm (21) and the distal end surface of the anchoring arm (22) are both arc surfaces.

5. The vena cava filter according to claim 1, characterized in that: The bare stent (11) comprises a plurality of stent rings (111), and the plurality of stent rings (111) are connected to the coating (12) in an arranged manner in pairs from the distal end of the coating (12) to the proximal end of the coating (12).

6. The vena cava filter according to claim 5, characterized in that: The support ring (111) is formed by connecting a plurality of V-shaped support units end to end.

7. The vena cava filter according to any one of claims 1 to 6, characterized in that: The filter body (2) further comprises a connecting sleeve (24); one end of the connecting sleeve (24) is connected to the end opposite to the hooking end of the recovery hook (23), and the proximal end of the fixing arm (21) and the proximal end of the anchoring arm (22) are both connected to the connecting sleeve (24).

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