An orderly and completely degradable covered bilayer stent

Abstract

The invention discloses an overlay film dual-layer stent capable of being orderly and completely degraded, and belongs to the technical field of medical apparatuses. The overlay film dual-layer stentcomprises an outer layer naked stent and an inner layer overlay film stent, wherein the stent part adopts biodegradable metal and alloy thereof or biodegradable high molecular materials, the expansionmanner is saccule expansion; an overlay film adopts biodegradable high molecular materials; the outer layer naked stent is released in advance, and can firstly pass through a lesion narrow section; the position and the length of the inner layer overlay film stent can be decided according to the situation of an aneurism neck and the situation of an interlayer aneurism cut; when being released, theinner layer overlay film stent is pressed in and fixed on the outer layer naked stent, so that the aneurism which is near an important collateral blood vessel can be treated; and after the aneurism is subjected to thrombosis and is contracted to a nature condition, the overlay film dual-layer stent is sequentially degraded according to the below sequence: degrading the overlay film, degrading theinner layer stent, degrading the outer layer naked stent, and finally performing complete degrading, so that the situation that foreign matters exist in vitro for a long time is avoided, and the situation that a person takes anti-thrombotic medicines for a long term is avoided.

Description

technical field [0001] The invention relates to the technical field of medical devices, in particular to a film-covered double-layer stent that can be degraded orderly and completely. [0002] technical background [0003] Dissection aneurysms, aneurysms and other lesions in vascular diseases can be treated with covered stents. The treatment principle is that the covered stent forms a barrier at the breach of the dissecting aneurysm and at the neck of the aneurysm. When the blood no longer flows into the aneurysm, the remaining blood in the aneurysm forms a thrombus and organizes into vascular tissue. The aneurysm wall in the expanded state shrinks due to negative pressure, reducing the mass effect, thereby achieving the purpose of treating the aneurysm. [0004] Currently, commercial stent grafts include: intracranial stent grafts such as Willis, coronary stent grafts such as JOSTENT Graftmaster stent and Symbiot stent, aortic stent grafts such as Valiant Captivia stent and...

AI Technical Summary

Problems solved by technology

After the stent completes its therapeutic function, the covering film will degrade by itself, but the double-layer stent itself is not degradable and will remain in the blood vessel

[0006] Patent 2 discloses a degradable stent graft, which is a fully degradable single-layer stent graft, but there is a risk of blocking important collateral vessels, and the stent graft is less flexible and difficult to pass through curved blood vessels

[0007] The covered stents disclosed in Patent 3 and Patent 4 are both single-layer degradable covered stents with adjustable size and position of the covered area. Although they can avoid blocking side vessels, the flexibility of the whole covered stent is not as good as that of the bare stent, making it difficult to Through the diseased area of ​​the aneurysm due to arteriosclerosis, it is not conducive to the release of the stent graft

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