Computational Evaluation of Artery Damage in Stent Deployment

This paper aims to evaluate damage in an arterial wall and plaque caused by percutaneous coronary intervention using a finite-element (FE) method. Hyperelastic damage models, verified against experimental results, were used to describe stress-stretch responses of arterial layers and plaque in the lumen; these models are capable to simulate softening behaviour of the tissue due to damage. Abaqus CAE was employed to create the FE models for an artery wall with two constituent layers (media and adventitia), a symmetric uniform plaque, a bioresorbable polymeric stent and a tri-folded expansion balloon. The effect of percutaneous coronary intervention on vessel damage was investigated by simulating the processes of vessel pre-dilation, stent deployment and post-stenting dilation. Energy dissipation density was used to assess the extent of damage in the tissue. Overall, the plaque experienced the most severe damage due to its direct contact with the stent, followed by the media and adventitia layers. Softening of the plaque and the artery due to the pre-dilation-induced damage can facilitate the subsequent stent-deployment process. The plaque and artery experienced heterogeneous damage behaviour after the stent deployment, caused by non-uniform deformation. The post-stenting dilation was effective to achieve a full expansion of the stent but caused additional damage to the artery. The computational evaluation of artery damage can be also potentially used to assess the risk of in-stent restenosis after percutaneous coronary intervention.