Hemodynamic Impact of Stenting on Carotid Bifurcation: A Potential Role in the Stented Segment and External Carotid Artery

Carotid stenting near the bifurcation carina is associated with adverse events, especially in-stent restenosis, in-stent thrombosis, and side branch occlusion in clinical data. This study aims to determine the potential biomechanical mechanisms for these adverse events after carotid stenting. The patient-specific carotid models were constructed with different stenting scenarios to study the flow distribution and hemodynamic parameters, such as wall shear stress (WSS), flow velocity, relative residence time (RRT), and oscillating shear index (OSI) in the carotid bifurcation. The results suggested that existing stent obviously reduced blood flow to external carotid artery (ECA) but enhanced local flow disturbance both in ECA and stented internal carotid artery (ICA), and the inner-posterior wall of stented ICA and the outer-posterior wall of ECA might endure a relatively low level of WSS and remarkably elevated OSI and RRT. In addition, the implanted stent leads to more ECA adverse flow than stented ICA. While disturbed flow in the vicinity of strut increased as stent length increased, blood flow and areas of local flow disturbance in ECA slightly decreased as stent length increased. In conclusion, the results revealed that ECA might be in relatively high levels of abnormal local hemodynamics after stenting, followed by stented ICA, leading to potential adverse events after interventions.