A computational study on vascular damage caused by shape memory alloy self-expandable and balloon-expandable stents in a stenosed artery

Abstract

Atherosclerosis is one of the major types of cardiovascular diseases. Stent deployment into the stenosed artery is the most common treatment for atherosclerosis. Two common stent models based on two different expansion principles are balloon-expandable and self-expandable stents. Depending on the modality of the expansion, the material used for these two stents varies. Despite the extensive progress made in the field of stent construction, plaque fragmentation and in-stent restenosis are two of the problems that still cause complications in stenting. Computational modeling and finite element method help us predict the damage effects to the artery and plaque in the stenting process. In this article, we simulate the insertion of two stents (the stainless steel stent and the shape memory alloy stent) in a diseased artery with real geometry. Results are compared to account for the effects of these stents on the artery, especially, the maximum stress in the plaque and arterial layers and surgically induced damage as the main cause of plaque fracture during the stent deployment and in-stent restenosis. It is found that arising from superelasticity, the shape memory alloy stent induces less damage to the artery. In addition, the stress created in the artery by the shape memory alloy stent is smaller. Therefore, the risk of plaque fragmentation and in-stent restenosis is reduced in shape memory alloy stents.