Influences of plaque eccentricity and composition on the stent-plaque-artery interaction during stent implantation

This work aims to investigate the effects of plaque eccentricity and composition on the stent performance and stress distributions of plaque and artery during stenting by the finite element method. Three-dimensional stent-plaque-artery models for plaques with five different eccentricities and four different compositions were simulated, and the influences on stent recoil, stent plastic strain, stent foreshortening, stress distributions of artery and plaque, and lumen gain were studied. The results show that greater plaque eccentricity leads to greater stent recoil, stent plastic strain, stent foreshortening, maximum von Mises stresses of artery and plaque, and volume percentage of plaque in higher stress. Plaque composition exerts a great effect on all indices except the maximum von Mises stress of artery. The lipid pool declines stent recoil, but increases the maximum plastic strain of stent due to its softness, while the fibrous cap reduces stent foreshortening. Because of the existence of fibrous cap/calcified zones, plaque with greater eccentricity and higher mixture of components is more vulnerable during stenting process; thus, a larger expanding pressure should be carefully applied and a slightly longer stent should be used. The present study suggests that the real plaque geometry and composition in numerical simulations should be considered as an integral part of stent design and development, also is useful in enhancing our understanding of the mechanics of stent-plaque-artery interaction during stent implantation to improve the stent's long-term clinical outcome.