In Silico Evaluation of Bilinear Elastoplastic Coronary Artery Stents

Mechanical responses of the endovascular stent determine the arterial homeostasis and vulnerability of the atherosclerotic plaque. Given the various plaque components when the stent is deployed, the stent may apply excessive stress to the lesion and cause plaque rupture. Herein, using the interaction between the Palmaz-Schatz stent with two stent biomaterials, stainless steel, and magnesium alloy, and three different types of plaque, namely hypocellular, hypercellular, and calcified, are studied. An implicit finite element method is used to simulate and analyze the stress and strain acting on the stents, artery, and plaques. The Mooney-Rivlin hyperelastic material model is considered to study the responses of each component. The results reveal that stainless-steel stents applied a higher level of stress to the plaques and vessel wall, which may lead to vascular damage and plaque rupture. However, a magnesium alloy stent with the similar design and geometrical parameters generates less stress on the plaque and artery. Interestingly, a minor improvement in magnesium alloy stents, increasing the strut thickness, can enhance the stent performance and lower the applied stresses to the vasculature and plaque, making them an ideal choice of material for stenting applications.