STENTS WITH LOW STRUT THICKNESS AND VARIABLE STRUT GEOMETRY

摘要

The invention disclosed herein is a balloon expandable metallic stent with low and uniform strut thickness for implantation in a body lumen such as artery. The stent consists of variable geometry of scaffold structure consisting of cells with open and closed configuration across its axial length to impart differential mechanical strength to different parts. The closed cell configuration is stronger than the open cell configuration and hence offers more resistance to radial expansion than the open cell configuration. The stent is divided into distinct sections of rows of closed and open cells. By providing closed cells in the end portions and open cells in the central portion of a stent, the dog-boning effect can be eliminated. Other configurations can be created by making only one end section of the stent with closed cells. The thickness of the stent made from cobalt-chromium alloy L-605 could be reduced to as low as 35 microns with adequate radial strength as well as fatigue resistance. The stent with thinner struts and elimination of dog-boning effect are known to reduce arterial injury.