Intravascular stent of composite structure

Abstract

The invention discloses an intravascular stent of a composite structure; the intravascular stent comprises a stent main body, wherein the distal end of the stent is restrained as an adducted form by virtue of a tightening wire, and the tightening wire is degradable magnesium alloy or degradable iron alloy; one or more auxiliary wires are woven on the stent main body; when the stent is applied to blood vessel of brain, the auxiliary wire is pure platinum or alloy thereof, pure gold or alloy thereof, pure tungsten or alloy thereof, or pure tantalum or alloy thereof; and when the stent is applied to peripheral blood vessel, the auxiliary wire is cobalt-chromium alloy or stainless steel or tungsten or tantalum. The stent, when serving as a thrombus removal system for treating cerebral apoplexy, not only can be used for removing thrombus effectively for several times but also can be used for catching small thrombus flowing to distal end so as to prevent distal blood vessels from getting blocked; and the stent can be used for dilating stenosis or blocked brain blood vessel or peripheral blood vessel, so as to take an effect of dredging and reconstructing a blood flow. The stent can be repositioned and released, with high controllability; and the stent can be used for reducing operation difficulty and greatly improving an operation success rate.

Description

technical field [0001] The invention relates to a composite structure intravascular stent, which belongs to the technical field of medical devices. Background technique [0002] Cerebral stroke is the most serious refractory disease that endangers human health and life safety. According to statistics, there are 3 million stroke patients in China every year, and 1.2 million stroke patients die every year. There are 8 million survivors of stroke, 6 million of whom have lost their labor force and are unable to take care of themselves to varying degrees. For patients with cerebral apoplexy who are sent to the hospital in time, the conventional treatment plan is drug thrombolysis, but the active ingredients of many drugs are difficult to reach the lesion, and it is difficult to ablate large thrombus, so that the intended treatment purpose cannot be achieved. Secondly, the best window time for drug thrombolysis (the time from the onset of the disease to the time of treatment) is ...

AI Technical Summary

Problems solved by technology

[0003] The Solitaire FRDevice of the American ev3 company and the TrevoRetriever of the American Stryker company have two common shortcomings in actual clinical use: 1) Both of them have no distal vascular protection design, and small thrombus will peel off from the main body and flow to the more distal end during use. blood vessels, thereby blocking smaller blood vessels, causing secondary strokes, and even endangering the patient's life

Larger braiding density will bring higher radial force, but the braiding density increases, the fore-shortening rate of the stent increases, and the release of the stent is difficult; on the other hand, if the braiding density is too small, it is difficult for the stent to maintain the design shape

A larger number of braided filaments will increase the radial force, but an increase in the number of braided filaments will require the use of a larger delivery catheter and increase the difficulty of the operation

Increasing the diameter of the braided wire will also increase the radial force, but the increase in the diameter of the braided wire will also require the use of a larger delivery catheter and increase the difficulty of the operation; on the other hand, the braided wire with a smaller diameter is more likely to break after long-term use

Braided wire with higher stiffness and elastic modulus will bring higher radial force; on the other hand, too high radial force of the stent will cause damage to the soft cerebral blood vessels

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