Comparison of intraoperative and postoperative duplex ultrasound for carotid endarterectomy

Intraoperative (IO) duplex ultrasound (DU) is used to identify correctable technical defects at the time of carotid endarterectomy (CEA). Postoperativ e (PC) DU is used to evaluate recurrent or residual stenosis. We compared I O and PC DU to determine the value and significance of these studies in the management of patients undergoing CEA. We performed completion 10 DU follo wing CEA and PC DU a mean of 8 weeks after surgery in 78 patients. 10 studi es were performed by the operating surgeon and PO studies were performed in an accredited vascular laboratory. Peak systolic velocity (PSV) was measur ed in the internal carotid (ICA), external carotid, and common carotid (CCA ) arteries. The criteria used for an abnormal study were an ICA PSV > 150 c m/sec and a ratio of ICA to CCA PSVs(ICA/CCA) >3.0. Completion angiograms w ere also performed on all patients intraoperatively. Technical defects iden tified on DU or angiogram were corrected whenever possible. From our result s, we concluded that in many patients, early PO DU will demonstrate an elev ated ICA PSV compared to the 10 PSV. If the ICA/CCA remains normal, this in crease is unlikely to represent a clinically relevant recurrent or residual stenosis, A postoperative ICA/CCA ratio >3.0 may be a more reliable indica tor of significant stenosis and a lesion that is likely to progress or occl ude than PSVs alone.