Anesthetic Cases of Carotid Endarterectomy

Abstract

We report consecutive carotid endarterectomy for 10 stroke patients, who were protected from cerebral ischemia with the aid of an indwelling shunt and monitoring by electroencephalogram (EEG) under general anesthesia with isoflurane.
During the cross-clamping of the carotid arteries for the insertion of an indwelling shunt catheter, eight patients showed slowed frequencies on the EEG and three of them exhibited lowered amplitudes, indicating cerebral ischemia. These changes in the EEG patterns were soon recovered with the blood supply started from the shunt. The same abnormalities were observed during the cross-clamping for withdrawal of the shunt. Unfortunately, two patients who showed lowered amplitudes on the EEG suffered transient motor paralysis, and one patient developed a small cerebral infarction caused by the relatively long clamping time reguired for suturing the hemorrhagic carotid artery. We conclude that carotid endarterectomy should be performed with a shunt that is indwelled and withdrawn within a possibly shortened clamping time of the carotid artery and that EEG monitoring is indispensable for detecting cerebral ischemia during the course of surgery and anesthesia.