Intraoperative duplex ultrasound during carotid endarterectomy.

The purpose of this study was to examine the technical aspects of intraoperative duplex ultrasound (DUS) following carotid endarterectomy (CEA), suggest criteria to differentiate significant lesions requiring immediate surgical revision from normal or benign defects, and evaluate how frequently intraoperative DUS provides useful or unsuspected information. A retrospective study was performed on all patients who had both CEA and intraoperative carotid DUS between January 1, 1990, and January 1, 1995. A total of 155 DUS examinations were performed in 149 patients. Findings were grouped into three categories: normal; minor/insignificant lesions; and hemodynamically significant lesions based on the presence or absence of elevated peak systolic velocities, visible stenosis/thrombus, or intimal flap/dissection. Postoperative status was correlated with intraoperative DUS findings. Ninety-one (59%) examinations performed on 87 patients produced normal findings. Forty-seven (30%) examinations performed on 45 patients showed minor abnormalities consisting of insignificant residual plaque, residual external carotid artery stenoses, small intimal flaps, elevated velocities with no associated anatomic lesion, or an arterial kink. Fourteen patients (9%) had significant findings requiring immediate surgical revision. These consisted of large intimal flaps or dissection in six patients, marked residual plaque and significant stenosis in five patients, thrombus in two patients, and a kink in one patient. Three additional patients (2%) had significant findings but were not revised for various reasons. No significant difference was identified in morbidity or mortality rates between those patients with normal findings, those patients with minor technical defects, and those patients with significant abnormalities undergoing immediate surgical revision. However, two of three patients who had significant abnormalities within the common carotid artery that were not revised suffered perioperative ipsilateral strokes. Intraoperative DUS is a safe and accurate method to assess the technical adequacy of CEA. Intraoperative DUS showed significant lesions in 11% of patients. Identification and immediate repair of significant technical defects may decrease perioperative complication rate and long-term restenosis rate.