Degradable double-layer stent

Abstract

The invention provides a degradable double-layer stent which is of a double-layer structure formed by sequentially connecting a roughly cylindrical keel stent and a dense net stent in a sleeved mode from outside to inside, the keel stent and the dense net stent are net-shaped braided fabric or net-shaped cut objects or the combination of the net-shaped braided fabric and the net-shaped cut objects, and the double-layer stent can be completely or partially degraded, wherein the wire diameter of the keel stent is larger than that of the dense net stent, and the mesh size of the keel stent is larger than that of the dense net stent. According to the invention, the full coverage rate of the inner-layer dense net stent is ensured, and the contact area of the outer-layer keel stent and the micro-catheter wall is relatively small, so that the whole stent has smaller pushing resistance; compared with a degradable stent with a single-layer structure, the double-layer stent has better anchoring performance and lower retraction rate in a blood vessel; after endovascular interventional therapy is completed, the stent can be partially or completely degraded, so that chronic problems caused by long-term retention of the stent in the body are reduced.

Description

technical field [0001] The invention relates to the field of medical devices, in particular to a degradable double-layer stent. Background technique [0002] In the field of vascular interventional therapy, stent implantation is a common treatment method. At present, commonly used intravascular stents are mainly made of biologically inert metals or alloys, such as stainless steel and nickel-titanium alloys. The mechanical properties of metal stents are quite different from those of human blood vessels. Due to their non-degradable properties, the stents will remain in the human body for a long time after implantation, which will cause a series of chronic problems, such as vascular damage and hyperplasia. And when the implanted stent site relapses and requires secondary treatment, the early implanted stent that has not been removed will greatly increase the complexity of the operation situation. [0003] In order to solve these problems, an ideal intravascular stent should gi...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a degradable double-layer stent, thereby solving the long-term safety problem of the metal stent in the human body in the prior art, and the problem of insufficient strength of the single-layer degradable polymer stent

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