Stent

Abstract

The present invention provides a stent which is flexible in the axial direction prior to the expansion of the stent, which shows no contraction in the axial length of the stent during expansion of the stent, which has an extremely large resistance to forces exerted by contracting blood vessels after expansion, which can cause uniform expansion of the struts of the stent, and in which there is no problem of the end portions of the stent warping to a greater diameter than the central portion of the stent at the time of expansion, furthermore a stent in which the size of the basic cells that constitute the stent is reduced so that bulging of endothelial cells of vascular tissues into the inside of the stent is suppressed, furthermore a stent which allows Y stenting into branched blood vessels while maintaining a high radial force and superior scaffold properties.

Description

technical field [0001] The present invention relates to a dilator to be placed or implanted in a vessel tissue in the body, for example, a dilator to be placed or implanted in a blood vessel in order to prevent restenosis of the narrowed or occluded part of the blood vessel after the dilation. Background technique [0002] The so-called dilator refers to a medical device placed there to maintain the size of the lumen to expand the stenosis or occlusion in order to treat various diseases caused by the stenosis or occlusion of blood vessels or other lumens in the living body. Among them, there are coils made of a single linear metal or polymer material, metal tubes are cut and processed by laser, linear components are assembled by laser welding, and multiple linear metals are braided. . These are disclosed in JP-A-8-332230. [0003] These are divided into those that are expanded by a stent fitted with a dilator and those that are self-expanding by externally removing a membe...

AI Technical Summary

Problems solved by technology

[0018] However, there is a disadvantage that the Y dilator cannot be transplanted to the above-mentioned bifurcated vessels.

That is, when the Y dilator is transplanted, even if the stent of the other dilator supply catheter is passed and expanded through the polygon forming the closed strut gap toward the side branch vessel, the polygon cannot be expanded because the perimeter of the polygon is limited. Larger opening, so there is a disadvantage of not being able to enter side branches

In order to solve it, it is also considered to increase the area of ​​the polygon, but this will sacrifice the structure (scaffold) like the open type

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