Effects of residual stenosis on carotid artery after stent implantation: A numerical study

Stent deployments with residual stenosis (RS) were linked to increased risk of in-stent restenosis and thrombosis. The objective of the present work was to explore the underlying biomechanical mechanism(s) for adverse events with RS. The patient-specific carotid models with RS were constructed to investigate wall shear stress (WSS), velocity, relative residence time (RRT), and oscillating shear index (OSI) after stenting in the host artery. The results showed that stented artery accompanied by RS would result in evident vortex, stagnation and recirculation zone at the stenosis throat, where relatively more areas were at abnormal low level of TAWSS, high level of RRT and OSI. Moreover, effects of stenting with RS on velocity, WSS, RRT and OSI in host artery would be significantly enhanced by severe RS, long stent and common carotid artery (CCA) stenting. These results indicated that stenting with RS might aggravate adverse flow around the stent and the other region without stent, leading to increased adverse events in clinic. Therefore, to obtain better poststenting outcomes, stenting with RS requires caution and careful consideration, especially for the host artery with a severe RS, long stent and some locations of stenting.