Carotid endarterectomy. The unreliability of intraoperative monitoring in patients having had stroke or reversible ischemic neurologic deficit

D. Rosenthal, P. E. Stanton Jr and P. A. Lamis

We reviewed 125 patients who had had stroke or reversible ischemic neurologic deficits (RIND) and who underwent carotid endarterectomy, with follow-up extending to six years. Phase I patients (n = 36) had endarterectomy and shunt placement at operation by surgeons' preference. The rate of postoperative neurologic deficit was 8%. Phase II patients (n = 36) had endarterectomy monitored by EEG and stump pressures. Postoperative deficits occurred in 9%. The EEGs and stump pressures in these patients were "normal"; therefore, no shunt was used. Phase III patients (n = 41) had endarterectomy again monitored by EEG and stump pressure. Despite normal EEGs or stump by EEG and stump pressure. Despite normal EEGs or stump pressure, all patients underwent endarterectomy with a temporary indwelling shunt. No complications occurred. In 368 patients operated on for transient ischemic attacks alone, the operative stroke rate was 1.6%. Stump pressure and EEG are unreliable indicators of cerebral perfusion during carotid endarterectomy in patients who have suffered stroke or RIND. Use of a temporary shunt is indicated in all of these patients.