CN113208772A

CN113208772A - Vena cava filter

Info

Publication number: CN113208772A
Application number: CN202110599635.8A
Authority: CN
Inventors: 郑殿会; 董永贺; 霍春青; 刘颖
Original assignee: Beijing Huamai Taike Medical Instrument Co ltd
Current assignee: Beijing Huamai Taike Medical Instrument Co ltd
Priority date: 2021-05-31
Filing date: 2021-05-31
Publication date: 2021-08-06

Abstract

The invention provides a vena cava filter, which relates to the field of medical instruments and comprises a support frame and a filter body; the filter body comprises a fixed arm, an anchoring arm and a recovery hook; the near end of the fixed arm and the near end of the anchoring arm are both connected to the opposite ends of the hook end of the recovery hook, the far end of the anchoring arm is provided with an anchoring part, and the anchoring part is anchored on the inner side surface of the support frame; in the released state: the support frame is unfolded to be cylindrical, and the far end of the fixing arm and the far end of the anchoring arm are opened towards the periphery, so that the fixing arm and the anchoring arm are unfolded to be umbrella-shaped; the anchoring portion can be disengaged from the support frame when the recovery hook receives an external force dragging towards the near end. The invention solves the problems that the hemorrhages of the implanted part are easy to occur after the vena cava filter is released in the blood vessel, the implantation time of the filter is short, and the filter is difficult to be safely taken out in the prior art, and simultaneously, the displacement of the filter after the vena cava filter is released in the blood vessel can be avoided.

Description

Vena cava filter

Technical Field

The invention relates to the technical field of medical instruments, in particular to a vena cava filter.

Background

Venous Thromboembolism (VTE) refers to the formation of Venous blood plaques, most commonly found in the deep veins of the lower extremities, called deep vein thrombosis. Emboli may be dislodged from the site where it was created and enter the blood circulation, a condition known as embolism. VTE has many clinical manifestations, venous thrombosis is generally asymptomatic, with occasional pain and edema in the lower extremities, and a proportion of emboli can enter the lungs, leading to potentially fatal pulmonary embolism; symptomatic venous thrombosis, which often leads to a series of complications; chronic venous dysfunction can cause long-term symptoms, thus leading to venous ulceration and limb changes after emboli have occurred, manifested as chronic pain, swelling and skin changes, and in severe cases, pulmonary embolism.

Pulmonary embolism refers to a pathological process caused by the occlusion of a pulmonary artery or branch thereof by an embolus. The diagnosis rate is low, the misdiagnosis rate is high, and the fatality rate is high. The scholars believe that 80-90% of pulmonary embolism comes from lower limb venous thrombosis, especially the probability of embolus falling off is higher in the process of thrombolytic therapy, and the large embolus can cause death of patients within minutes. The death rate of pulmonary embolism caused by iliac femoral vein thrombosis is reported to be up to 20% -30%. The typical symptoms of pulmonary embolism are three major signs of dyspnea, chest pain, cough and hemoptysis. Is the second hyperfibrino tramadol in pulmonary valve area with rales, so the prevention of pulmonary embolism is more important than the treatment in clinic.

At present, the pulmonary embolism prevention is mainly realized by adopting a mode of implanting a vena cava filter into a lower cavity in clinic. The vena cava filter is an instrument made of metal wires and is placed into the infrarenal veins through a special conveying device to intercept large thrombus in blood flow and avoid entering pulmonary artery along with the blood flow to cause lethal pulmonary embolism.

The existing vena cava filter mainly comprises a filtering arm consisting of a fixed arm and an anchoring arm and a recovery hook connected with the near end of the filtering arm, wherein the far end of the anchoring arm is provided with the anchoring hook, and the recovery hook is used for capturing the recovery hook in a blood vessel and then pulling out the blood vessel to realize the recovery of the filter after the filter is implanted into a human body for a period of time; the anchoring hook is of a barb structure, and the barb of the filter is inserted into the vein blood vessel wall to prevent the filter from being displaced after the filter is released in the blood vessel.

However, the existing vena cava filter has at least the following problems:

since the vein is very thin, the barb anti-displacement structure of the anchoring hook can easily stab or pierce the blood vessel, so that the condition that the implanted part is bleeding is caused, the injury to the blood vessel is larger, meanwhile, the barb anti-displacement structure pierces the blood vessel wall, the endothelium of the blood vessel is proliferated, the endothelial tissue can gradually cover the vena cava filter after a period of time, the filter and the blood vessel are grown together, the filter is difficult to withdraw from the blood vessel, and the contact area between the filter and the blood vessel tissue is larger, the contact time is longer, and the filter is difficult to recover from the blood vessel. The recovery time is too short, the time for the filter to act in the blood vessel is short, and thus the treatment effect cannot be achieved; in addition, because the anchoring hook is punctured into the vessel wall, after the filter is withdrawn from the vessel, a large wound exists at the original contact part, the wound part has large damage to the vessel, and thrombus is easy to gather again;

in addition, after the vena cava filter is released in a blood vessel, the filter is easy to incline, the recovery hook is contacted with the blood vessel wall, the recovery hook is not easy to be caught by a recovery device, and recovery is difficult to realize.

In summary, in the prior art, the problems that the implantation part bleeds easily after the vena cava filter is released into the blood vessel, the implantation time of the filter is short, the filter is difficult to take out safely and the like occur.

Disclosure of Invention

The invention aims to provide a vena cava filter, which solves the problems that the vena cava filter is easy to bleed at the implanted part after being released in a blood vessel, the filter is short in implantation time and difficult to safely take out after being released in the blood vessel in the prior art on the basis of avoiding the filter from shifting after the vena cava filter is released in the blood vessel.

In order to achieve the above purpose, the embodiment of the invention adopts the following technical scheme:

the embodiment of the invention provides a vena cava filter, which comprises a support frame and a filter body; the filter body comprises a fixed arm, an anchoring arm and a recovery hook; the near end of the fixed arm and the near end of the anchoring arm are both connected to the opposite ends of the hooking end of the recovery hook, the far end of the anchoring arm is provided with an anchoring part, and the anchoring part is anchored on the inner side surface of the support frame; in the released state: the supporting frame is unfolded to be cylindrical, and the far end of the fixing arm and the far end of the anchoring arm are opened towards the periphery, so that the fixing arm and the anchoring arm are unfolded to be umbrella-shaped; the anchoring portion can be disengaged from the support frame when the recovery hook is subjected to an external force dragging towards the near end.

In an alternative embodiment, a developing portion is provided on the support frame, and a developing coating is provided on the anchor arm.

In an alternative embodiment, the scaffold comprises a bare stent and a cover membrane attached to the bare stent; the anchor is anchored to the bare stent or the cover.

In an alternative embodiment, the distal end of the anchoring arm is provided with a bend that bends towards the opening direction upon release, the bend constituting the anchoring portion; a fixing piece is connected to the inner side surface of the covering film, and the fixing piece fixes the bending part to the inner side surface of the covering film; the curved portion is capable of disengaging the fastener when the retrieval hook is subjected to a proximally-trailing external force.

In an alternative embodiment, the fixing member comprises a developing ring and/or a suture, wherein "and/or" means that the fixing member may be a developing ring or a suture, or in the fixing member, the developing ring and the suture are used at the same time, respectively, for fixing different bending portions.

In an alternative embodiment, the length of the anchoring arm is greater than the length of the fixing arm, and the anchoring portion is provided at a portion where the distal end of the anchoring arm is longer than the fixing arm.

In an alternative embodiment, the distal end surface of the fixation arm and the distal end surface of the anchoring arm are both curved surfaces.

In an alternative embodiment, the bare stent comprises a plurality of stent rings, and the stent rings are connected to the covering membrane in a pairwise spaced arrangement from the distal end of the covering membrane to the proximal end of the covering membrane.

In an alternative embodiment, the stent ring is formed by connecting a plurality of V-shaped stent units end to end.

In an alternative embodiment, the strainer body further comprises a connection sleeve; one end of the connecting sleeve is connected to the opposite end of the hooking end of the recovery hook, and the near end of the fixed arm and the near end of the anchoring arm are both connected to the connecting sleeve.

The embodiment of the invention can realize the following beneficial effects:

the embodiment of the invention provides a vena cava filter, which comprises a support frame and a filter body; the filter body comprises a fixed arm, an anchoring arm and a recovery hook; the near end of the fixed arm and the near end of the anchoring arm are both connected to the opposite ends of the hook end of the recovery hook, the far end of the anchoring arm is provided with an anchoring part, and the anchoring part is anchored on the inner side surface of the support frame; in the released state: the support frame is unfolded to be cylindrical, and the far end of the fixing arm and the far end of the anchoring arm are opened towards the periphery, so that the fixing arm and the anchoring arm are unfolded to be umbrella-shaped; the anchoring portion can be disengaged from the support frame when the recovery hook receives an external force dragging towards the near end.

The embodiment of the invention solves the problems that the hemorrhaging of an implanted part is easy to occur after the vena cava filter is released in a blood vessel, the implantation time of the filter is short, and the filter is difficult to safely take out in the prior art on the basis of avoiding the filter from shifting after the vena cava filter is released in the blood vessel, and the specific structure and the obtained functional effect are shown in the specific implementation mode.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic diagram of the overall structure of a support frame in a vena cava filter according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of the overall structure of a filter body in a vena cava filter according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of the overall structure of a vena cava filter in a released state according to an embodiment of the present invention;

fig. 4 is a partial structure enlarged view of a portion a in fig. 3.

Icon: 1-a support frame; 11-a bare stent; 111-a scaffold ring; 12-coating a film; 2-filter body; 21-a fixed arm; 22-anchoring arms; 221-a curved portion; 23-a recovery hook; 24-connecting sleeves; 3-developing ring.

Detailed Description

In order to make the objects, 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 with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it should be noted that the terms "proximal", "distal", "inside", "outside", and the like refer to positions or positional relationships based on the positions or positional relationships shown in the drawings, or the positions or positional relationships that the products of the present invention conventionally use, and are used for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus should not be construed as limiting the present invention.

In particular, in the present invention, the term "proximal" refers to the end closer to the human heart during surgery, and "distal" refers to the end opposite the "proximal".

In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," and "connected" are to be construed broadly, e.g., as meaning fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Some embodiments of the invention are described in detail below with reference to the accompanying drawings. The embodiments described below and the features of the embodiments can be combined with each other without conflict.

The present embodiment provides a vena cava filter, which, with reference to fig. 1-4, comprises a support frame 1 and a filter body 2. Specifically, the strainer body 2 includes a fixing arm 21, an anchoring arm 22, and a recovery hook 23; the near end of fixed arm 21 and the near end of anchoring arm 22 all are connected in the opposite end of retrieving the hook end of hook 23, and the distal end of anchoring arm 22 is equipped with the anchor portion, and the anchor portion anchors in the medial surface of support frame 1. In the released state: the supporting frame 1 is expanded to be cylindrical, and the far ends of the fixing arms 21 and the far ends of the anchoring arms 22 are opened towards the periphery, so that the fixing arms 21 and the anchoring arms 22 are expanded to be umbrella-shaped; the anchor portion can be detached from the support frame 1 when the recovery hook 23 receives an external force dragging toward the near end. In the present embodiment, the specific number of the fixing arms 21 and the anchoring arms 22 is not particularly limited, and may include, but is not limited to, 10

fixing arms

21 and 2 anchoring arms 22.

Before thrombus treatment: the vena cava filter is implanted at the position of the intravascular thrombus filter by using an implanting device, the support frame 1 and the filter body 2 are released, the support frame 1 is expanded to be cylindrical to be supported on the inner wall of a blood vessel, and the fixing arm 21 and the anchoring arm 22 are expanded to be umbrella-shaped; then, a filtering arm consisting of the fixing arm 21 and the anchoring arm 22 of the filter body 2 is used for filtering larger venous thrombus to prevent 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 pulling the recovery hook 23 proximally, so that the filter body 2 containing the filtered thrombus is detached from the holder 1 and withdrawn outside the blood vessel, and the holder 1 is permanently placed in the body.

In this embodiment, the anchoring portion of the filter body 2 is anchored to the inner side surface of the support frame 1, rather than being directly anchored to the blood vessel wall, so that the vena cava filter provided by this embodiment can achieve at least the following beneficial effects:

(1) after release, the support frame 1 is expanded into a cylindrical shape to be supported on the inner wall of the blood vessel, so that the support frame has good supporting and displacement preventing effects and can prevent the filter from displacing;

(2) the supporting frame 1 is opened to be cylindrical, the blood vessel is not damaged by the implantation of the supporting frame 1, the filter body 2 is not in direct contact with the blood vessel wall after the vena cava filter is completely released, the blood vessel can be prevented from being punctured or punctured after the filter is implanted, and the problem that the implanted part of the vena cava filter is bled after the vena cava filter is released in the prior art is solved;

(3) after the vena cava filter is completely released, the vena cava filter is not contacted with the filter body 2 in the vascular endothelial hyperplasia process, and the filter body 2 can still be pulled out from the support frame 1 after being implanted for a long time, so that the taking-out time of the filter body 2 is prolonged, the recovery time is long enough, the filter body 2 can filter large thrombus in a human body for a long time, and the problem that the implantation time of the filter is short after the vena cava filter is released into a blood vessel in the prior art is solved;

(4) after the vena cava filter is completely released, the vascular wall is not contacted with the filter body 2, so that the blood vessel is not pulled when the filter body 2 is withdrawn, the filter body 2 is easy to withdraw, and the blood vessel is not damaged in the process of withdrawing the filter body 2;

(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 fixing arm 21 and the anchoring arm 22 of the filter body 2 are supported on the support frame 1, so that the filter body 2 can be prevented from inclining, and further, the filter body 2 can be kept in a filtering posture constantly, the catching and recovering hook 23 can be favorably caught, the filter body 2 can be favorably withdrawn, and the process of withdrawing the filter body 2 has no damage to blood vessels.

In conclusion, the embodiment solves the problems that the hemorrhaging of the implanted part is easy to occur after the vena cava filter is released in the blood vessel, the filter implantation time is short, and the filter is difficult to safely take out in the prior art on the basis of avoiding the vena cava filter from being released in the blood vessel and then the filter is displaced.

In order to accurately obtain the implantation position, in the present embodiment, a developing part is provided on the support frame 1, and a developing coating is applied on the anchoring arm 22; the developing part preferably comprises a far-end developing part, a middle developing part and a near-end developing part, which are respectively sewn or connected to the support frame 1 in other modes, the middle developing part is preferably arranged at or near a pre-anchoring position of the anchoring part 1, the far-end developing part and the near-end developing part are respectively and correspondingly arranged at the far end closest to the support frame 1 and the near end closest to the support frame 1, and the developing part is used as a reference contrast in the operation process to ensure that the release positions of the support frame 1 and the filter body 2 are accurate.

Referring to fig. 1 to 4, in an alternative embodiment of the present embodiment, preferably, the scaffold 1 includes a bare stent 11 and a covering membrane 12 connected to the bare stent 11; the anchoring part is anchored on the bare stent 11 or the tectorial membrane 12, preferably, the far ends of the fixing arms 21 and the far ends of the anchoring arms 22 do not exceed the far end part of the tectorial membrane 12, and after the vena cava filter is completely released, the far ends of the fixing arms 21 are spread on the outer side or the inner side of the tectorial membrane 12. The covering film 12 may be connected to the inner side of the bare stent 11 or connected to the outer side of the bare stent 11, and preferably, the bare stent 11 is connected to the outer side of the covering film 12 to increase the displacement resistance of the support frame 1, and meanwhile, the compliance of the bare stent 11 is improved, and the specific connection manner of the bare stent 11 and the covering film 12 includes, but is not limited to, as shown in fig. 1 to 4, the bare stent 11 is sewn to the covering film 12. In this alternative embodiment, the coating 12 may be a fabric coating or a polymer coating, and is preferably, but not limited to, a polymer coating that is more suitable for human body to reduce or avoid immunological rejection of human body to the coating 12.

In the optional embodiment of this embodiment, the specific structure of the anchoring portion has a variety of structures, including but not limited to a hook or barb structure that is bent toward the opening direction when releasing, and 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 on the inner side surface of the support frame 1, and although the anchoring portion is the hook or barb structure, its anchoring position is located on the support frame 1, not the blood vessel wall, and thus, the blood vessel will not be damaged, and the specific structure of the anchoring portion may also be other structures. Among the plurality of alternative structures of the anchoring portion, it is preferable that, in the strainer body 2, the distal end of the anchoring arm 22 is provided with a bent portion 221 bent toward the releasing-time opening direction, the bent portion 221 constituting the anchoring portion; a fixing member is connected to the inner surface of the coating 12, and the fixing member fixes the bending portion 221 to the inner surface of the coating 12; the curved portion 221 can be disengaged from the fixing member when the recovery hook 23 receives an external force dragging toward the proximal end; the fixing member includes, but is not limited to, a development ring 3 or a suture as shown in fig. 4.

When the fixing member is the developing ring 3, specifically: the developing ring 3 can be but not limited to be sewn on the inner side surface of the covering film 12 through a suture, the developing ring 3 is positioned in a groove of the bending part 221, so that the bending part 221 is clamped and fixed on the inner side surface of the covering film 12 through the developing ring 3, after the vena cava filter is implanted into a blood vessel, the support frame 1 and the filter body 2 are released for filtering, when the filter body 2 needs to be retracted, the recovery hook 23 is pulled towards the proximal direction through proper external force, the bending part 221 can be pulled out of the developing ring 3, the filter body 2 is further separated from the support frame 1, and further, the filter body 2 is withdrawn to the outside of the blood vessel.

When the anchoring element is a suture, in particular: the curved part 221 is sutured to the bare stent 11 and/or the covering membrane 12 by a suture thread in a way that the thread end part is not fixed, after the vena cava filter is implanted into the blood vessel, the support frame 1 and the filter body 2 are released for filtering and embolization, when the filter body 2 needs to be withdrawn, the recovery hook 23 is dragged towards the proximal direction by proper external force, the suture thread on the curved part 221 can be pulled off from the bare stent 11 and the covering membrane 12, the filter body 2 is further separated from the support frame 1, and further, the filter body 2 is withdrawn to the outside of the blood vessel.

In an alternative embodiment of this embodiment, it is preferred that the distal end of each anchoring arm 22 is provided with at least one bend 221, and to further avoid displacement or tilting of the filter body 2 for increased anchoring stability, it is preferred that at least two bends 221 are provided spaced apart from each other.

In an alternative embodiment of this embodiment, it is preferable that the anchoring arm 22 has a length greater than that of the fixing arm 21, and the anchoring portion is provided at a position where the distal end of the anchoring arm 22 is longer than the fixing arm 21, for the purpose of anchoring.

In addition, in order to avoid the fixed arm 21 and the anchoring arm 22 from scratching blood vessels during implantation or withdrawal, in an alternative embodiment of the present embodiment, it is preferable that the distal end surface of the fixed arm 21 and the distal end surface of the anchoring arm 22 are both curved surfaces, preferably hemispherical surfaces.

In an optional embodiment of the present embodiment, it is preferable that the bare stent 11 includes a plurality of stent rings 111, the stent rings 111 are connected to the covering membrane 12 in a spaced arrangement from the distal end of the covering membrane 12 to the proximal end of the covering membrane 12, and the arrangement of the stent rings 111 increases the adherence of the covering membrane 12, so as to prevent large thrombi from leaking out from between the covering membrane 12 and the blood vessel wall, and improve the effectiveness of thrombus filtration. To increase the supporting force of the support ring 111, it is preferable that the support ring 111 is formed by connecting a plurality of V-shaped support units end to end.

In addition, in an optional embodiment of the present embodiment, it is preferable that the strainer body 2 further includes a connection sleeve 24; one end of the connecting sleeve 24 is connected to the opposite end of the hooking end of the recovery hook 23, the proximal ends of the fixing arms 21 and the proximal ends of the anchoring arms 22 are connected to the connecting sleeve 24, the connecting sleeve 24 may 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 fixing arm 21 and the proximal end of the anchoring arm 22 are welded to the connecting sleeve 24.

In this embodiment, the entire filter body 2 is preferably made of steel or other metal.

Finally, it should be noted that: the embodiments in the present description are all described in a progressive manner, each embodiment focuses on the differences from the other embodiments, and the same and similar parts among the embodiments can be referred to each other; the above embodiments in the present specification are only used for illustrating the technical solutions of the present invention, and not for limiting the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A vena cava filter, characterized by comprising a support frame (1) and a filter body (2);

the filter body (2) comprises a fixed arm (21), an anchoring arm (22) and a recovery hook (23);

the near end of the fixed arm (21) and the near end of the anchoring arm (22) are both connected to the opposite ends of the hooking end of the recovery hook (23), the far end of the anchoring arm (22) is provided with an anchoring part, and the anchoring part is anchored on the inner side surface of the support frame (1);

in the released state: the supporting frame (1) is unfolded to be cylindrical, and the far ends of the fixing arms (21) and the far ends of the anchoring arms (22) are opened towards the periphery, so that the fixing arms (21) and the anchoring arms (22) are unfolded to be umbrella-shaped;

the anchoring portion can be detached from the support frame (1) when the recovery hook (23) receives an external force dragging toward the near end.

2. Vena cava filter according to claim 1, characterized in that a visualization portion is provided on the support frame (1) and a visualization coating is provided on the anchoring arms (22).

3. The vena cava filter according to claim 1,

the support frame (1) comprises a bare stent (11) and a covering film (12) connected to the bare stent (11);

the anchoring portion is anchored to the bare stent (11) or the cover film (12).

4. A vena cava filter according to claim 3,

the distal end of the anchoring arm (22) is provided with a bent portion (221) bent toward the opening direction upon release, the bent portion (221) constituting the anchoring portion;

a fixing piece is connected to the inner side surface of the covering film (12), and the bending part (221) is fixed to the inner side surface of the covering film (12) by the fixing piece;

the curved portion (221) can be disengaged from the fixing member when the recovery hook (23) receives an external force dragging toward the proximal end.

5. Vena cava filter according to claim 4, characterized in that the fixation means comprise a visualization ring (3) and/or a suture.

6. Vena cava filter according to claim 1, characterized in that the length of said anchoring arm (22) is greater than the length of said fixation arm (21), said anchoring portion being provided at a location where the distal end of said anchoring arm (22) is longer than said fixation arm (21).

7. Vena cava filter according to claim 1, characterized in that the distal end face of the fixation arm (21) and the distal end face of the anchoring arm (22) are both cambered surfaces.

8. The vena cava filter according to claim 3, wherein the bare stent (11) comprises a plurality of stent loops (111), the plurality of stent loops (111) being attached to the membrane (12) in a spaced-apart arrangement from a distal end of the membrane (12) to a proximal end of the membrane (12).

9. Vena cava filter according to claim 8, characterized in that the stent ring (111) is formed by a plurality of V-shaped stent units connected end to end.

10. A vena cava filter according to any of claims 1-9, characterized in that the filter body (2) further comprises a connection 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 near end of the fixing arm (21) and the near end of the anchoring arm (22) are both connected to the connecting sleeve (24).