Preoperative risks predict neurological outcome of carotid endarterectomy related stroke

The aim of this study was to determine if preoperative risk factors are predictors of poor stroke outcome after carotid endarterectomy. In addition, the effect of other stroke risk factors on stroke severity was determined. A retrospective review of carotid endarterectomy results spanning 10 years, encompassing 561 patients, and reporting the combined results of all surgeons at our institution was performed. Patients were assigned to one of four groups. There were 227 patients with no preoperative risks (Group 1), 61 with angiographic risks (Group 2), 196 with medical risks with or without angiographic risks (Group 3), and 77 with neurological risks with or without medical/angiographic risks (Group 4). Other risks associated with stroke occurrence were recorded including: intraoperative risks (cross-clamp time, use of shunt, use of glucose solutions), surgical complications (carotid occlusion/thrombus or ligation), and medical complications (hypoxia, myocardial infarct). Stroke incidence was 5% with 2% (11 patients) and 3.4% (19 patients) having good and poor outcomes, respectively. Stroke incidence was highest in Groups 2 and 4 (10 and 14%, respectively), and Group 4 had the highest incidence of poor-outcome stroke (12%). Cross-clamp time, intraoperative shunt placement, and intraoperative glucose administration were similar among preoperative risk groups and were not primary determinants of stroke severity. The most common medical complication was myocardial infarction, which had the highest incidence in Groups 3 and 4 (6.1 and 5%, respectively). The highest incidence of surgical complications occurred in Groups 2 and 4, carotid thrombosis being the most common event (16 patients). Surgical complications were more commonly associated with stroke than were medical complications. Carotid reexploration was successful in improving the neurological outcome in only 2 of 9 patients. Our results show that the best predictor of both stroke occurrence and poor stroke outcome was the preoperative risk group. Within this general database, we could not identify any specific technical factors of surgery or anesthesia that were associated with the risk of stroke.