Investigation of the Hemodynamics of Coronary Arteries - Effect of Stenting

Cardiovascular diseases (CVD) are the leading cause of death in the world. According to the World Health Organization (WHO) 17.3 million people died from cardiovascular disease in 2008, representing 30% of all global deaths. The most common modality of treatment of occluded arteries is the use of stents. Despite the widespread use of stents, the incidence of post-stent restenosis is still high. The study of stents in conditions that are similar to in-vivo conditions is limited. This work tries to address the behavior of stents in conditions similar to in-vivo conditions in a generalized framework, thus providing insights for stent design and deployment. Three dimensional, time accurate computational fluid dynamics (CFD) simulations in a pulsatile flow with fluid-structure interaction (FSI) were carried out in realistic coronary arteries, with physiologically relevant flow parameters and dynamics due to induced motion of the heart. In addition, the geometric effects of the stent on the artery were studied to point towards possible beneficial stent deployment strategies. The results suggest that discontinuities in compliance and dynamic geometry cause critical changes in local hemodynamics, namely altering the local pressure and velocity gradients. Increasing the stent length, reducing the transition length and increasing the overexpansion caused adverse flow conditions. From this work, detailed flow characteristics and hemodynamic characteristics due to the compliance mismatch and applied motion were obtained that gave insights towards better stent design and deployment.