Finite-element analysis of a stenotic artery revascularization through a stent insertion

Short-term and long-term clinical follow-up data clearly indicate the superiority of stenting techniques within the family of mechanical treatments for percutaneous coronary revascularizations. However, restenosis phenomena are in general still present, representing the major drawback for this innovative non-invasive approach. Experimental evidence indicates the mechanical interaction between the stent and the artery as a significant cause for the activation of stent-related restenosis. At the same time, the literature shows a significant lack of computational investigations within this field, possibly as consequence of the complexity of the problem. According to these considerations, the aim of the present work is to study the biomechanical interaction between a balloon-expandable stent and a stenotic artery, highlighting considerations able to improve the general understanding of the problem. In particular, given an initial stent design (J&J Palmaz-Schatz like), we show the presence of possible areas of artery injury during the stent deployment and areas of nonuniform contact pressure after the stent apposition, due to a non-uniform stent expansion. Since these concentrated mechanical actions can play an important role in the activation of restenosis mechanisms, we propose a modified stent design, which shows a more uniform expansion and for which typical stenting parameters (i.e., residual stenosis, elastic recoil, foreshortening) are computed and presented.