Prophylactic effectiveness for the brain infarction of the administration of 20% Mannitol was reported in five consecutive cases carried out carotid endarterectomy. Clamping time of carotid arteries were ranged from 29 minutes to 62 minutes with 44.4 minutes in mean.
No neurological sequela has appeared after operation. Serial electroencephalogram during carotid endarterctomy and CT findings taken after the operation showed no significant abnormalities.