A Critical Analysis of Design, Development, and Failure of Existing Stents

Abstract

A lot of researches have contributed toward the design, optimization, and improvement of the stent from the last few decades. But, most of these stent designs have their limitations and drawbacks, which have been studied. This paper reviews some existent stents and suggests where and why does the structure of the stent fail. The key mechanical integrity, related to stent designing, and its deployment have been considered as an objective and constraint function of this analysis. Like stresses on the stent, equivalent plastic strain PEEQ, recoil, and foreshortening of stent, artery too have stress development and foreshortening, since arterial cells also have some constraints in both the longitudinal and circumferential directional stretch. The cause of failure of five stents structures, reported in the literature, is suggested in this work. To reduce the computational time, a unit cell of the stent and cylindrical artery has taken for simulation. The finite element method is employed for the analysis of all mechanical behavior at various load conditions throughout the percutaneous coronary intervention PCI process, and the results are reported.