THE CAUSE OF PERIOPERATIVE STROKE AFTER CAROTID ENDARTERECTOMY

Purpose: The purpose of this study was to examine the cause of perioperative stroke after carotid endarterectomy. Methods: The records of 2365 patients undergoing 3062 carotid endarterectomies from 1965 through 1991 were reviewed. Sixty-six (2.2%) operations were associated with a perioperative stroke. The mechanism of stroke was determined in 63 of 66 cases. Patient risk factors and surgeon-dependent factors were analyzed. Results: More than 20 different mechanisms of perioperative stroke were identified, but most could be grouped into broad categories of ischemia during carotid artery clamping (n = 10), postoperative thrombosis and embolism (n = 25), intracerebral hemorrhage (n = 12), strokes from other mechanisms associated with the surgery (n = 8), and stroke unrelated to the reconstructed artery (n = 8). Dividing the operative experience approximately into thirds, during the years 1965 to 1979, 1980 to 1985, and 1986 to 1991 the perioperative stroke rates were 2.7%, 2.2%, and 1.5%, respectively. This, in part, is associated with a better selection of patients (more symptom free, fewer with neurologic deficits). There has been a notable decrease in perioperative stroke caused by ischemia during clamping and intracerebral hemorrhage, but postoperative thrombosis and embolism remain the major cause of neurologic complications. Conclusions: Although patient selection seems to play a role, most perioperative strokes were due to technical errors made during carotid endarterectomy or reconstruction and were preventable.