The significance of early postoperative duplex studies following carotid endarterectomy

This study was conducted to evaluate the significance of duplex ultrasound performed soon after carotid endarterectomy. The records of patients with 150 carotid endarterectomies and postoperative duplex ultrasound within 24 h were reviewed. Eleven (7.3%) had abnormal studies with > or =50% stenosis. Two patients with abnormal studies sustained a perioperative stroke and three patients underwent reoperation for persistent lesions (P<0.0001). Preoperative and postoperative cerebral imaging studies (computed tomography (CT) or magnetic resonance imaging (MRI)) were performed on 114 patients. Seven of these demonstrated areas of infarction and all seven had abnormal duplex ultrasound studies. Twenty-six CT scans were performed with two positive for cerebral infarction in the two patients with clinical stroke. In the 88 MRI studies, five demonstrated small, subcortical focal areas of ischemia, which were clinically silent. The relationship of infarction on postoperative cerebral studies and abnormal postoperative duplex ultrasound was significant (P<0.0001). It was concluded that early postoperative duplex ultrasound studies of > or =50% stenosis demonstrate significant association with postoperative stroke or reoperation, as well as with ischemic changes on brain imaging studies. Earlier detection with intraoperative duplex would probably be more advantageous than postoperative duplex ultrasound.