The impact of stenosis treatment on the hemodynamic crosstalk between carotid arteries.

Biomechanical analysis of crosstalk between the carotids remains poorly underexplored. This study aims to clarify the impact of severe carotid stenosis on the local hemodynamics of the opposite carotid artery, before and after treatment. Data from patients diagnosed with severe internal carotid artery stenosis (≥ 70%), treated with carotid artery stenting (CAS) or carotid endarterectomy (CEA) were analyzed. Both sides' anatomical and hemodynamic remodeling parameters were evaluated before and after treatment. Forty-two patients underwent computed tomography angiography (CTA) and phase-contrast magnetic resonance imaging (PC-MRI) to measure carotid diameters and flow rates in the common, internal, and external carotids (CCA, ICA, and ECA, respectively) before and after CAS or CEA. Additionally, patient-specific computational fluid dynamics (CFD) simulations were performed to calculate time-averaged wall shear stress (taWSS) before and after the treatment. Post-treatment analysis revealed anatomical and hemodynamic changes in the contralateral side. Specifically, there was a decrease in blood flow and an increase in vessel diameters, particularly in the CCA, of patients who had undergone CEA (pre vs. post: flow p = .029, diameter p = .007). Additionally, there was an increase in low taWSS areas in the SOI after the operation: CEA from 15.50 (10.80) % to 18.00 (20.25) %, CAS from 17.00 (15.55) % to 19.50 (20.50) %. The study revealed new anatomical and hemodynamic parameters changes in both carotids, offering insights into the interaction between stenotic and contralateral carotid arteries in post-operative conditions.