Cerebral Perfusion In Patients With Carotid Stenosis Undergoing Carotid Endarterectomy

Objective:Asymptomatic patients with carotid stenosis benefit less from carotid endarterectomy (CEA) than symptomatic patients because the risk of embolic events is lower, but it is not known whether the hemodynamic effect of CEA is different between the groups. We evaluated hemodynamics of symptomatic and asymptomatic patientgroups before and after CEA. Methods:35 independent patients with a unilateral high-grade carotid stenosis,12asymptomatic and 23symptomatic, underwent dynamic susceptibility contrast MRI (DSC-MRI) evaluation before CEA and 7 and 180 days afterward. Quantitative perfusion parameters were calculated separately in selected regions of white and gray matter and watershed regions in each hemisphere, and mean transit time (MTT) maps were assessed visually by independent observers. Results:In contrast to the asymptomatic carotid stenosis group, symptomatic carotid stenosis patients had preoperatively increased MTT and lower cerebral blood flow values in the ipsilateral hemisphere, more in white matter and watershedregions than in gray matter. Visually detected perfusion deficits were associated with symptomatic status. The interhemispheric asymmetries were abolished by CEA. The improving trend over time was greater in the symptomaticcarotid stenosis group and was best seen in MTT. Conclusions:Patients with asymptomatic and symptomatic carotid stenosis differ significantly by means of DSC-MRI before and in response to CEA.