Vena cava filter

Abstract

The utility model discloses a vena cava filter which comprises a filter body and a plurality of supporting assemblies arranged outside the filter body and supported on a blood vessel wall, the supporting assemblies are arranged in the circumferential direction of the filter body at intervals, and each supporting assembly comprises a wall attaching piece attached to the blood vessel wall and a connecting piece connected between the filter body and the wall attaching piece. The connecting piece is made of a degradable metal material, the wall attaching piece is made of a degradable high polymer material, and the filter main body is made of a metal material; when the vena cava filter is arranged in a blood vessel, the filter main body is not in contact with blood in the blood vessel, and a spacing distance is formed between the outer contour surface of the filter main body and the blood vessel wall; the connecting piece is in direct contact with blood in a blood vessel, the filter main body and the connecting piece can be indirectly communicated with a positive electrode and a negative electrode of a power supply respectively, and when current passes through the connecting piece, the connecting piece can be electrolyzed to separate the filter main body from the connecting piece. The vena cava filter can be implanted into the blood vessel of a patient for a long time and cannot damage the blood vessel when taken out.

Description

Technical Field

[0001] The utility model relates to the technical field of medical devices, and particularly relates to an inferior vena cava filter. Background Art

[0002] In order to prevent the occurrence of deep vein thrombosis and pulmonary embolism, an inferior vena cava filter can be placed in the body. In the existing technology, when encountering cases that require relatively long-term implantation of the inferior vena cava filter, due to the long-term implantation of the inferior vena cava filter, the inferior vena cava filter will be wrapped by the newly formed intima, making it impossible to pull out the inferior vena cava filter from the blood vessel wall. If pulled out forcibly, the newly formed intima of the blood vessel will be torn, and in severe cases, blood vessel rupture may occur. Summary of the Utility Model

[0003] The purpose of the utility model is to provide an inferior vena cava filter that can be implanted for a long time and will not damage the blood vessel intima when removed, aiming at the problems in the existing technology.

[0004] To achieve the above purpose, the technical solution adopted by the utility model is:

[0005] An inferior vena cava filter includes a filter main body, and further includes a support assembly disposed outside the filter main body and supported on the blood vessel wall. A plurality of the support assemblies are circumferentially and spaced apart from each other along the filter main body. The support assembly includes a wall-attaching member that fits with the blood vessel wall and a connecting member connected between the filter main body and the wall-attaching member. The connecting member is made of a biodegradable metal material, the wall-attaching member is made of a biodegradable polymer material, and the filter main body is made of a metal material;

[0006] When the inferior vena cava filter is placed in a blood vessel, the filter main body is not in contact with the blood in the blood vessel, and there is a spacing distance between the outer contour surface of the filter main body and the blood vessel wall; the connecting member is in direct contact with the blood in the blood vessel, and the filter main body and the connecting member can be indirectly connected to the positive and negative electrodes of a power supply respectively. When there is an electric current passing through the connecting member, the connecting member can be electrolyzed to separate the filter main body from the connecting member.

[0007] In some embodiments, the inferior vena cava filter further includes a recovery assembly for recovering the filter main body. The recovery assembly includes a recovery hook disposed at the end of the filter main body and a capture ring detachably connected to the recovery hook. Both the capture ring and the recovery hook are made of a metal material, and when recovering the filter main body, both the capture ring and the recovery hook are isolated from the blood in the blood vessel;

[0008] When one of the positive and negative electrodes of the power supply is connected to the capture ring and the other is connected to the human body, a current loop is formed among the capture ring, the recovery hook, the filter main body, the connecting member, and the human body.

[0009] In some embodiments, the recovery assembly further includes a recovery sheath made of a polymer material. When recovering the filter body, the capture ring and the recovery hook are both received inside the recovery sheath.

[0010] In some embodiments, the capture ring includes a ring body detachably connected to the recovery hook and a guide wire with one end disposed on the ring body. Both the ring body and the guide wire are made of a metal material, and the other end of the guide wire extends outside the human body and is connected to the positive or negative pole of a power source.

[0011] In some embodiments, the filter body is coated with an insulating layer so that the filter body does not contact the blood in the blood vessel, and the insulating layer is a polymer coating.

[0012] In some embodiments, the material of the connecting member is one of magnesium alloy, zinc alloy, and ferroalloy, and the material of the wall-attaching member is one of polylactic acid, polyglycolide, and polycaprolactone.

[0013] In some embodiments, in the blood environment in the blood vessel, the degradation periods of both the wall-attaching member and the connecting member are not less than 180 days.

[0014] In some embodiments, the extending direction of the wall-attaching member is the same as the extending direction of the blood vessel, and the cross-sectional area of the wall-attaching member is larger than the cross-sectional area of the connecting member.

[0015] In some embodiments, the filter body includes a main body portion located in the middle and contraction portions respectively disposed at both ends of the main body portion. The contraction portions are made of a plurality of nitinol wires, and one ends of the plurality of nitinol wires away from the main body portion are received together.

[0016] In some embodiments, the filter body has a wedge-shaped structure.

[0017] Due to the application of the above technical solutions, the inferior vena cava filter of the present utility model has the following advantages compared with the prior art:

[0018] (1) This inferior vena cava filter can be implanted in the blood vessel for a long time.

[0019] (2) When the inferior vena cava filter is taken out, an electric current can pass through the filter body and the connecting member. When the electric current passes through, since the filter body does not contact the blood in the blood vessel while the connecting member contacts the blood in the blood vessel, the connecting member can be electrolyzed, and the filter body and the connecting member can be separated. Since there is a spacing distance between the outer contour surface of the filter body and the blood vessel wall, the filter body will not be wrapped by the vascular intima, and the filter body will not damage the blood vessel when taken out. The wall-attaching member and the connecting member remaining in the human body will be completely degraded after a period of time, so that no foreign objects will be left in the blood vessel and no harm will be caused to the human body. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a front view schematic diagram of the inferior vena cava filter of this embodiment;

[0021] Figure 2 is a front view schematic diagram of the inferior vena cava filter of this embodiment after removing the capture ring and the retrieval sheath;

[0022] Figure 3 is a three-dimensional schematic diagram of the inferior vena cava filter of this embodiment after removing the capture ring and the retrieval sheath;

[0023] Figure 4 is a top view schematic diagram of the inferior vena cava filter of this embodiment after removing the capture ring and the retrieval sheath;

[0024] Figure 5 is a structural schematic diagram of the inferior vena cava filter of this embodiment placed in a blood vessel;

[0025] Figure 6 is a structural schematic diagram of the inferior vena cava filter of this embodiment placed in a blood vessel for a certain period of time with the blood vessel intima wrapping the wall attachment member;

[0026] Figure 7 is a structural schematic diagram of the power supply of this embodiment.

[0027] Wherein: 1. Filter main body; 11. Main body part; 12. Shrinkage part; 2. Retrieval assembly; 21. Retrieval hook; 22. Capture ring; 221. Ring body; 222. Guide wire; 23. Retrieval sheath; 3. Support assembly; 31. Wall attachment member; 32. Connecting member; 41. Blood vessel wall; 42. Blood vessel intima; 5. Power supply. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0029] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. is based on the orientation or positional relationship shown in the accompanying drawings. For example Figure 1In the figure, the left side of the figure is "front", the right side is "rear", the upper side is "up", the lower side is "down", and the direction perpendicular to the paper surface in the figure is "left" and "right". This is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0030] As Figure 1 shown, the inferior vena cava filter of this embodiment includes a filter main body 1, a recovery assembly 2, and a support assembly 3.

[0031] The filter main body 1 has a wedge-shaped structure and can contract and expand radially. When the filter main body 1 is placed in a patient's blood vessel for protection, the filter main body 1 is in an expanded state. During the process of implanting the filter main body 1 into the patient's blood vessel or during the recovery process, the filter main body 1 is in a contracted state.

[0032] Specifically, as Figure 1 and Figure 2 shown, the filter main body 1 includes a main body portion 11 and a contraction portion 12. The main body portion 11 is located in the middle of the filter main body 1, and the contraction portions 12 are respectively arranged at both ends of the main body portion 11. The filter main body 1 has a mesh structure. Specifically, the main body portion 11 is in the shape of a mesh cylinder, and the contraction portion 12 is in the shape of a mesh cone. The large end of the contraction portion 12 faces the main body portion 11, and the small end is away from the main body portion 11.

[0033] The material of the main body portion 11 is nitinol, and it can be formed by braiding nitinol metal wires or processed from nitinol material through a laser engraving process.

[0034] The contraction portion 12 is made of multiple nitinol wires, and one ends of the multiple nitinol wires away from the main body portion 11 are received together.

[0035] As Figure 1 shown, the recovery assembly 2 includes a recovery hook 21, a capture ring 22, and a recovery sheath 23.

[0036] The recovery hook 21 can be fixedly arranged at the small end of the contraction portion 12 at one end of the filter main body 1, or can be respectively arranged at the small ends of the contraction portions 12 at both ends of the filter main body 1. The recovery hook 21 is made of platinum material and is connected to the small end of the contraction portion 12 by welding or riveting.

[0037] The capture loop 22 is detachably connected to the retrieval hook 21. When the capture loop 22 and the retrieval hook 21 are connected to retrieve the filter body 1, by pushing the retrieval sheath 23, the capture loop 22 and the retrieval hook 21 can both be received in the retrieval sheath 23, and the filter body 1 can be converted from the expanded state to the contracted state and enter the retrieval sheath 23, thus facilitating the removal from the blood vessel.

[0038] The capture loop 22 includes a loop body 221 and a guide wire 222. The loop body 221 is detachably connected to the retrieval hook 21. One end of the guide wire 222 is fixedly arranged on the loop body 221, and the other end of the guide wire 222 extends out of the human body.

[0039] In this embodiment, both the loop body 221 and the guide wire 222 are made of metal materials. Specifically, the outer layer material of the loop body 221 is gold-plated tungsten wire, and the inner core material is nitinol wire. The guide wire 222 can be made of nitinol alloy material.

[0040] As Figures 1 to 6 shown, the support assembly 3 is connected to the filter body 1 and is located outside the filter body 1. When the inferior vena cava filter is placed in the blood vessel, the support assembly 3 abuts against the blood vessel wall 41, thereby fixing the filter body 1 in the blood vessel. A plurality of support assemblies 3 are arranged at intervals along the circumference of the filter body 1, so as to better position the filter body 1 in the blood vessel, making the filter body 1 not prone to tilt and displacement, and improving the protection effect of the inferior vena cava filter.

[0041] Specifically, each support assembly 3 includes a wall-attaching member 31 and a connecting member 32. When the inferior vena cava filter is placed in the blood vessel, the wall-attaching member 31 fits against the blood vessel wall 41 for positioning. One end of the connecting member 32 is connected to the wall-attaching member 31, and the other end is connected to the main body part 11 of the filter body 1. The connecting member 32 extends radially outward from the connection part with the main body part 11, so that when the inferior vena cava filter is placed in the blood vessel, there is a certain distance between the outer contour surface of the filter body 1 and the blood vessel wall 41, so that when the filter body 1 is implanted in the patient's blood vessel for a long time, the filter body 1 will not be wrapped by the vascular intima 42, as Figure 6 shown, so that the blood vessel will not be damaged when the filter body 1 is taken out alone. In this way, the filter body 1 can achieve the effect of long-term implantation in the patient's blood vessel, thereby improving the protection effect.

[0042] The connecting member 32 is made of metal material, and the wall-attaching member 31 is made of polymer material. In this embodiment, the connecting member 32 is connected to the main body part 11 of the filter body 1 by welding, and the connecting member 32 is connected to the wall-attaching member 31 by hot melting.

[0043] The extending direction of the wall-attaching member 31 is consistent with the extending direction of the blood vessel, and the cross-sectional area of the wall-attaching member 31 is larger than that of the connecting member 32, so that a larger contact area is provided between the wall-attaching member 31 and the blood vessel wall 41, thereby providing a more stable supporting force within the blood vessel wall 41, effectively improving the stability of the filter body 1 in the blood vessel and preventing the filter body 1 from tilting.

[0044] The filter body 11 is coated with an insulating layer, which plays an insulating role, so that when the filter body 11 is placed in the blood vessel, it does not come into contact with the blood in the blood vessel. The insulating layer can be a polymer coating, and the polymer coating can be made of polytetrafluoroethylene, etc. The recovery sheath 23 is made of a polymer material, such as nylon, polyether block polyamide pebax, high-density polyethylene hdpe, etc.

[0045] When recovering the filter body 1, the ring body 221 of the capture ring 22 is sleeved on the recovery hook 21, and the recovery sheath 23 is pushed. The recovery sheath 23 covers the recovery hook 21, that is, the recovery hook 21, the ring body 221 and the guide wire 222 located in the blood vessel are all received in the recovery sheath 23. One of the positive and negative electrodes of the power supply 5 is connected to the guide wire 222 of the capture ring 22, and the other is connected to the human body. In this way, a current loop is formed among the guide wire 222, the ring body 221, the recovery hook 21, the filter body 1, the connecting member 32 and the human body. The power supply 5 can be a DC power supply of 8 - 24V, and the power supply 5 is as Figure 7 shown. When the power supply 5 is turned on, since the filter body 11 does not come into contact with the blood in the blood vessel, and at the same time, since the guide wire 222, the ring body 221 and the recovery hook 21 are all received in the recovery sheath 23, the recovery sheath 23 can shield the electric field environment in the external blood. In this way, the current is concentrated on the connecting member 32, and the connecting member 32 will be continuously electrolyzed until it breaks and separates from the filter body 11. At this time, the recovery sheath 23 can be continuously pushed to recover the filter body 1 into the recovery sheath 23 and taken out of the body. And part of the non-electrolyzed connecting member 32 and the wall-attaching member 31 will remain in the blood vessel. When taking out the filter body 1, since the filter body 1 is not wrapped by the blood vessel intima 42, the blood vessel will not be damaged during the removal.

[0046] The connecting member 32 is made of a degradable metal material, such as magnesium alloy, zinc alloy, iron alloy, etc. The wall-attaching member 31 is made of a degradable polymer material, such as polylactic acid PLA, polyglycolide PGA, polycaprolactone PCL, etc. In this way, when the non-electrolyzed connecting member 32 and the wall-attaching member 31 remain in the blood vessel, they can be completely degraded within a certain period of time, and no foreign objects will be left in the blood vessel, thus not causing harm to the human body.

[0047] In the blood environment of the blood vessel, the degradation periods of both the wall-attaching member 31 and the connecting member 32 are not less than 180 days. This enables the filter body 1 to be implanted in the patient's blood vessel for a long time for protection.

[0048] The above embodiments are only used to illustrate the technical concept and features of the present invention. The purpose is to enable those skilled in the art to understand the content of the present invention and implement it, and it should not be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. An inferior vena cava filter, comprising a filter body, characterized in that: It further includes a support assembly disposed outside the filter body and supported on the blood vessel wall. A plurality of the support assemblies are circumferentially spaced along the filter body. The support assembly includes a wall-attaching member that fits against the blood vessel wall and a connecting member connected between the filter body and the wall-attaching member. The connecting member is made of a degradable metal material, the wall-attaching member is made of a degradable polymer material, and the filter body is made of a metal material; When the inferior vena cava filter is placed in a blood vessel, the filter body does not contact the blood in the blood vessel, and there is a spacing distance between the outer contour surface of the filter body and the blood vessel wall; the connecting member is in direct contact with the blood in the blood vessel, and the filter body and the connecting member can be indirectly connected to the positive and negative electrodes of a power supply respectively. When there is an electric current passing through the connecting member, the connecting member can be electrolyzed to separate the filter body from the connecting member.

2. The inferior vena cava filter according to claim 1, characterized in that: The inferior vena cava filter further includes a recovery assembly for recovering the filter body. The recovery assembly includes a recovery hook disposed at an end of the filter body and a capture ring detachably connected to the recovery hook. Both the capture ring and the recovery hook are made of a metal material, and when recovering the filter body, both the capture ring and the recovery hook are isolated from the blood in the blood vessel; When one of the positive and negative electrodes of the power supply is connected to the capture ring and the other is connected to the human body, a current loop is formed among the capture ring, the recovery hook, the filter body, the connecting member, and the human body.

3. The vena cava filter according to claim 2, wherein: The recovery assembly further includes a recovery sheath made of a polymer material. When recovering the filter body, both the capture ring and the recovery hook are received inside the recovery sheath.

4. The inferior vena cava filter according to claim 2, characterized in that: The capture ring includes a ring body detachably connected to the recovery hook and a guide wire with one end disposed on the ring body. Both the ring body and the guide wire are made of a metal material, and the other end of the guide wire extends outside the human body and is connected to the positive or negative electrode of the power supply.

5. The vena cava filter according to claim 1, wherein: The filter body is coated with an insulating layer so that the filter body does not contact the blood in the blood vessel, and the insulating layer is a polymer coating.

6. The inferior vena cava filter according to claim 1, wherein: The material of the connecting member is one of magnesium alloy, zinc alloy, and ferroalloy, and the material of the wall-attaching member is one of polylactic acid, polyglycolide, and polycaprolactone.

7. The inferior vena cava filter according to claim 1 or 6, characterized in that: In the blood environment in the blood vessel, the degradation period of both the wall-attaching member and the connecting member is not less than 180 days.

8. The inferior vena cava filter according to claim 1, wherein: The extending direction of the wall-attaching member is consistent with the extending direction of the blood vessel, and the cross-sectional area of the wall-attaching member is larger than the cross-sectional area of the connecting member.

9. The vena cava filter according to claim 1, characterized in that: The filter body includes a main body portion in the middle and contraction portions respectively disposed at both ends of the main body portion. The contraction portions are made of a plurality of nitinol wires, and one ends of the plurality of nitinol wires away from the main body portion are received together.

10. The inferior vena cava filter according to claim 9, characterized in that: The filter body has a wedge-shaped structure.

Images