Ultrasonografic monitoring of hemodynamic parameters in symptomatic and asymptomatic patients with high-grade carotid stenosis prior and following carotid endarterectomy

Abstract

Doppler ultrasonography is now a reliable diagnostic tool for noninvasive examination of the morphology and hemodynamic parameters of extracranial segments of blood vessels that participate in the brain vascularisation. This diagnostic modality in recent years become the only diagnostic tool prior to surgery. The aim of the study was to determine hemodynamic status in symptomatic and asymtomatic patients with severe carotid stenosis prior to and after carotid endarterectomy (CEA). A total of 124 symptomatic and 94 asymptomatic patients who had underwent CEA at the Clinic for Cardiovasculare Disease "Dedinje" in Belgrade were included in this study. Doppler ultrasonography examinations were performed one day before CEA and seven days after it. The peak systolic velocity (PSV), end-dyastolic velocity (EDV), time-averaged maximum blood flow velocity (MV), resistance index (RI) and the blood flow volume (BFV) of the ipsilateral and the contralateral internal carotid artery (ICA) were measured. Diabetes was the only risk factor found significantly more frequent in symptomatic patients. There were significantly more occluded contralateral ICAs in the group of symptomatic patients. There was a significant increase in PSV, EDV, MV and BFV of the ipsilateral ICA after CEA and a significant decrease in PSV, EDV, MV and BFV of the contralateral ICA after CEA. RI is the only hemodynamic parameter without significant changes after CEA in both groups of patients. Comparing the values of hemodynamic parameters after CEA between the group of symptomatic and the group of asymptomatic patients no significant differences were found. The occlusion of the contralateral ICA is an important factor differentiating between symptomatic and asymptomatic patients with severe carotid stenosis. Successful surgery provides good recovery of cerebral hemodynamics in both symtomatic and asymptomatic patients.