Cerebral protection during carotid endarterectomy

BACKGROUND: Perioperative stroke rates with carotid endarterectomy are 3.4% for asymptomatic and 5.2% for symptomatic patients. Several methods are used to limit perioperative stroke. METHODS: A retrospective chart review of consecutive carotid endarterectomies from January 1, 2000 to February, 28, 2003, was performed. Data were collected on patient demographics, operative procedure, intraoperative monitoring, and outcome. Comparative analysis of intraoperative monitoring and outcome was performed. RESULTS: Two hundred twenty-nine patients underwent 251 carotid endarterectomies. In 196 procedures decision to shunt was based on intraoperative monitoring, 129 by electroencephalogram (EEG), and 67 by stump pressures. Sixteen neurologic events occurred perioperatively, one transient ischemic attack and 15 strokes. The EEG group had 12 strokes, with a 38% event rate in procedures with EEG changes without shunting. The stump pressure group had one stroke. Stroke rate for intraoperative EEG monitoring was elevated (P = 0.02). CONCLUSIONS: Intraoperative EEG based decision to shunt may not be as effective as other methods for prevention of perioperative neurologic events. When EEG changes occur, shunting is necessary.