Complications of carotid endarterectomy: the influence of case load

We reviewed the records of 508 consecutive carotid endarterectomies done by 19 surgeons during a five-year period in one medical center to evaluate postoperative complications (stroke and death). Each of 16 surgeons did 32 operations or fewer, with case loads ranging from one to 32. Three surgeons did 70, 98, and 172 respectively. The incidence of stroke among patients of the 16 surgeons combined who did 32 cases or fewer in five years (fewer than ten cases per year) was 7%, with a combined stroke and death rate of 8%; in contrast, patients of the combined surgeons who did more than 32 operations in five years (more than ten cases per year) had a stroke rate of 3%, with a combined stroke and death rate of 3%. When the carotid disease was examined separately, it was apparent that the adverse event rate among patients with asymptomatic or nonhemispheric disease accounted for the difference. Patients of surgeons with fewer cases had 18% adverse events, whereas those of more experienced surgeons had 2% adverse events. The adverse events were similar for both groups in patients with focal transient ischemic attacks or stroke. Seven of the 16 surgeons who did fewer than 32 cases had no patients who had stroke, despite the few carotid endarterectomies they had done. Thus, the stroke rate was somewhat lower in the hands of those surgeons who did endarterectomy more often, but the number of carotid endarterectomies done by a surgeon is not the only factor to decrease the stroke rate. Proper selection of patients and attention to risk factors and technique are essential.