INTRAOPERATIVE DUPLEX SCANNING FOR CAROTID ENDARTERECTOMY

Objectives: To evaluate the results of intraoperative duplex scans dur ing carotid endarterectomy. Design: Retrospective case review. Materia ls: One-hundred consecutive intraoperative carotid duplex scans perfor med during carotid endarterectomy between July 1993 and December 1995 at a university teaching hospital. Methods: Abnormalities of the B-mod e image and/or the Doppler flow analysis were classified. The results of intraoperative carotid duplex scans (ICDS) were related to the even ts of the intraoperative course, perioperative neurologic morbidity an d mortality, and to residual carotid stenosis. Results: Abnormalities of the ICDS were demonstrated in 13 cases (13%). Abnormalities were cl assified into four types: I, internal carotid artery spasm (n=9); II, high distal resistance flow (n=2); III, high grade residual stenosis ( n=1); IV, intraluminal thrombosis (n=1). Immediate intraoperative expl oration and revision of the endarterectomy was performed based on the ICDS in two cases (type III and IV) and the findings of ICDS were conf irmed. The other II cases with abnormal ICDS (types I, II) were not re vised and duplex scans done I month postoperatively (available in 10 c ases) showed normal carotid artery flow. Intraoperative angiography wa s performed selectively in five cases and confirmed the results of ICD S. Reversible abnormalities of the ICDS were not associated with perio perative morbidity or residual carotid stenosis. Conclusions: Intraope rative carotid duplex scanning can be used to assess the immediate tec hnical adequacy of carotid endarterectomy. B-mode image and Doppler fl ow abnormalities which are reversible can be distinguished from those which require immediate revision.