Hemodynamic analysis of carotid endarterectomy

Abstract

Atherosclerotic stenosis of the carotid artery may lead to cerebral infarction, stroke, and other serious consequences, and it is usually treated clinically with carotid endarterectomy. By comparing the pre- and postoperative flow fields, it can be shown that the operation improves hemodynamic parameters, such as the velocity, wall shear stress, and wall pressure of the local flow field of the carotid artery. However, previous studies have rarely considered the difference between postoperative and healthy carotid flow fields, and thus, the cause of any postoperative restenosis may remain hidden. Therefore, this study constructed preoperative, postoperative, and (hypothetically) healthy carotid artery models based on the real vascular structure data of a patient and applied numerical simulations verified by physical models to compare hemodynamic parameters, such as flow rate, flow state, and wall shear. The results showed that after the operation, the maximum carotid blood flow velocity decreased from 2.8 to 1.02 m/s, the maximum wall shear stress decreased from 190 to ∼75 Pa, the wall pressure of the carotid inlet recovered from 3000 to 400 Pa, and the vortex in the distal internal carotid artery disappeared. In addition, this study also found a vortex and the low-level wall shear stress of approximately 5 Pa remained in the carotid bifurcation after the operation, which also lacked spiral flow, unlike the healthy model. Therefore, due to the morphological differences between the postoperative and healthy carotid artery, adverse hemodynamic factors and a potential risk of postoperative restenosis will remain after the procedure.