Causes of Early Post Carotid Endartectomy Stroke in a Recent Series: The Increasing Importance of Hyperperfusion Syndrome

Early stroke occurs in 0.9% to 7% of patients undergoing carotid endarterectomy (CEA). These have been thought to be mostly due to embolization. However, in our recent clinical experience, we noted hyperperfusion syndrome to be a significant cause of postoperative strokes. Therefore, we reviewed our experience and investigated the distribution of causes of early postoperative strokes.A retrospective chart review of 444 consecutive patients who underwent CEA at our institution between June 1997 and October 1999 (500 operations) was performed to evaluate the incidence and etiology of early postoperative strokes. Indications for operation included history of stroke correlating with the side of ICA stenosis (50 patients or 10%), symptoms of transient ischemic attacks (84 patients or 16.8%), amaurosis fugax (18 patients or 3.6%), or asymptomatic stenosis (348 patients or 69.6%). All patients were evaluated with duplex scan preoperatively and postoperatively. Diagnosis of early postoperative strokes within one month after CEA was made based on clinical examination. Postoperative CT scan of the brain was available in 100% of patients with suspected diagnosis of CVA.Five patients (3 male and 2 female) were diagnosed with strokes postoperatively (1%). These five were symptomatic patients with ICA stenosis > or = 80% and moderate contralateral ICA stenosis. In two of those patients (40%), the reason for the stroke was considered embolization to the cerebral arteries; one patient suffered a shunt injury as a cause of stroke; two patients (40%) were diagnosed with hyperperfusion syndrome. In both patients diagnosis was made clinically, and in only one of those patients the clinical picture correlated with CT scan. Two patients (0.4%) had asymptomatic ICA occlusion at 2 weeks and 18 days postoperatively.Embolization to the cerebral arteries remains the leading cause of early postoperative strokes. However, hyperperfusion syndrome also accounts for a significant portion of these postoperative strokes. The percentage of patients with this syndrome might be even higher, once clinical picture is clearly defined. These data warrant further investigation of hyperperfusion syndrome.