Stent Graft

Abstract

A covered stent, comprising an outer membrane (103), an inner membrane (100) and a bare stent (101) which is disposed between the outer membrane (103) and the inner membrane (100), at least one tying wire (102) being disposed on an outer surface of the outer membrane (103) or / and between the outer membrane (103) and the inner membrane (100). The tying wire (102) is wound in a ring or a spiral shape about an outer surface of the bare stent (101), an inner surface of the bare stent (101) or an outer surface of the inner membrane (100); or the tying wire (102) passes between an inner surface and an outer surface of two connection rods of the bare stent (101). By using an anti-extension function of the tying wire (102) and by means of a coating means of the tying wire (102), a covered stent is effectively prevented from expanding under the impact of high pressure blood flow, thereby reducing the risk of function loss of the covered stent due to the expansion of the covered stent.

Description

technical field [0001] The invention relates to the technical field of interventional medical devices, in particular to a covered stent. Background technique [0002] The covered stents currently on the market generally include a bare stent and a single-layer PET film structure or a double-layer ePTFE / PTFE film structure arranged on the bare stent. These covered stents isolate the blood flow from the lesion through the covering, and eliminate the influence of blood pressure on the lesion, so as to achieve the purpose of healing. After the single-layer PET covered stent is implanted in the body, the connecting rod of the bare stent of the covered stent will be directly exposed in the blood, and the metal ions released by the connecting rod (such as nickel ions released by the nickel-titanium alloy stent in the blood) enter the blood In the circulation, it will cause adverse effects on the human body, such as carcinogenic and so on. The single-layer PET membrane structure is...

AI Technical Summary

Problems solved by technology

[0003] Although the existing invasive double-layer ePTFE / PTFE / FEP covered stent can reduce the ion release of the connecting rod of the stent and strengthen the biocompatibility between the stent and the inner wall of the blood vessel to a certain extent, the ePTFE / PTFE / FEP covered stent (such as figure 1 The adventitia 802 and the intima 800 in the stent) have certain ductility in the circumferential direction, and after being impacted by high-pressure blood flow for a long time, the stent (such as figure 1 Both the bare stent 801) and the ePTFE / PTFE / FEP coating will expand to a certain extent, and in severe cases, the coating will rupture, and the isolation function of the stent will fail.

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