Anti-displacement vena cava filter

Abstract

The invention provides an anti-displacement vena cava filter, and relates to the field of medical instruments. The anti-displacement vena cava filter comprises a covered stent, a filter main body and a recovery line; the filter main body comprises a recovery rod, a sleeve and a plurality of filter arms; the recovery rod penetrates through the sleeve, and the part, located in the sleeve, of the recovery rod is connected to the inner wall of the sleeve through a spring. The near ends of the plurality of filter arms are uniformly connected to the radial circumferential surface of the sleeve around the recovery rod; an anchoring ring is arranged at the far end of at least one filter arm, the near end of the recovery line is connected to the far end of the recovery rod, and the anchoring ring is connected to a covering film of the covered stent through the far end of the recovery line; in the release state, the spring is in a compressed state; under the condition that the near end of the recovery rod is subjected to external force dragging towards the near end, the spring can be further compressed, and the far end of the recovery wire can be separated from the anchoring circular ring. The technical problems that in the prior art, after the vena cava filter is released in a blood vessel, bleeding of an implanted part is likely to happen, the implanting time of the filter is short, and the filter is difficult to take out safely are solved.

Description

technical field [0001] The invention relates to the field of medical devices, in particular to an anti-displacement vena cava filter. Background technique [0002] At present, the method of implanting the vena cava filter into the inferior cavity is often used clinically to prevent pulmonary embolism. The vena cava filter is a device made of metal wire, which is placed into the subrenal vein through a special delivery device to intercept large thrombi in the blood flow and prevent them from entering the pulmonary artery with the blood flow and causing fatal pulmonary embolism. [0003] The existing vena cava filter mainly includes a filter arm composed of a fixed arm and an anchor arm, and a recovery hook fixedly connected to the proximal end of the filter arm. The distal end of the anchor arm is provided with an anchor hook. After being implanted in the human body for a period of time, the recovery hook is caught in the blood vessel through the recovery device, and then pu...

AI Technical Summary

Problems solved by technology

[0005] Because the veins are very thin, the barb anti-displacement structure of the anchor hook is easy to puncture or puncture the blood vessel, resulting in bleeding at the implantation site and greater damage to the blood vessel. At the same time, the anti-displacement structure of the barb The structure penetrates the vessel wall, the vessel endothelium proliferates, and the endothelial tissue will gradually cover the vena cava filter after a certain period of time, causing the filter and vessel to grow together, which will make it difficult to withdraw the filter from the vessel, and the filter and The larger the contact area of ​​blood vessel tissue and the longer the contact time, the more difficult it is for the filter to be recovered from the blood vessel. However, if the recovery time is too short, the time for the filter to function in the blood vessel is short, so the therapeutic effect is far from being achieved; in addition, due to the anchor hook Piercing into the blood vessel wall, after the filter is withdrawn from the blood vessel, there will be a large wound at the original contact site, the wound site will cause greater damage to the blood vessel, and it is very easy to gather thrombus again;

[0006] In addition, after the vena cava filter is released in the blood vessel, the filter is easy to tilt, and the recovery hook is in contact with the blood vessel wall, which makes the recovery hook difficult to be caught by the recovery device, and it is difficult to achieve recovery. The part of the hook is provided with a large-angle bending part, which is used to contact the blood vessel wall to prevent tilting. However, in actual use, it is found that this type of vena cava filter cannot completely avoid tilting, but only reduces the incidence of filter tilting. When the filter is anchored, there are only a few points of contact, and blood will impact the filter. Under such complicated conditions, it is also easy to cause the filter to tilt when it is released, making it difficult for the filter to be safely removed from the blood vessel after completing its mission. question etc.

[0007] In summary, in the prior art, after the vena cava filter is released in the blood vessel, it is prone to bleeding at the implantation site, the filter implantation time is short, and the filter is difficult to remove safely.

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