Prospective analysis of carotid endarterectomy and silent cerebral infarction in 97 patients.

To determine the incidence of perioperative silent cerebral infarction, 97 patients who underwent carotid endarterectomy were prospectively studied with preoperative and postoperative computed tomograms. Thirty-one of 96 patients (32%) had findings of cerebral infarction on preoperative computed tomograms. Silent cerebral infarction was found preoperatively in 17 patients (18%) (lacunar infarction in 10, cortical infarction in five, both cortical and lacunar infarctions in one, and cerebellar infarction in one). Transient ischemic attacks occurred in 10 of the 17 patients with silent cerebral infarction; however, symptoms were appropriate to the site in only five of these 10 patients. Fourteen of the 17 patients with silent cerebral infarction had a hemodynamically significant carotid stenosis, and seven patients had an ulcerated plaque on preoperative angiogram. The incidence of these lesions was similar to that found in the group of 66 patients without cerebral infarction. Endarterectomy specimens revealed a higher but not significantly different incidence of ulcerated plaque in the silent cerebral infarction group. There were no perioperative deaths. Following surgery, one patient (1%) with a preoperative silent cerebral infarction suffered a transient ischemic attack, and two patients (2%) with normal preoperative computed tomograms developed permanent neurologic deficits with new cortical infarctions on postoperative computed tomograms. No new silent cerebral infarctions were found on postoperative computed tomograms in any of the 97 patients. Our data suggest that silent cerebral infarction is a common preoperative finding with an as-yet unclear etiology and that carotid endarterectomy does not appear to be a cause.