INTRAOPERATIVE DUPLEX SCANNING AND LATE CAROTID-ARTERY STENOSIS

Purpose: The purpose of this study was to assess the effect of intraop erative duplex scanning on early and late results after carotid endart erectomy. Methods: We reviewed 316 carotid arteries in 283 patients wh o underwent operation Since 1986. The results of intraoperative ultras onography were normal in 254 (80.4%) and abnormal in 62 (19.6%). We di d not reexplore 53 (85.5%) of the abnormalities because the defect was minor, 2 to 3 mm or less. These defects were retained atheroma in the common carotid artery (n = 35), internal carotid artery (ICA) (n = 5) , external carotid artery (n = 2), small frond in the bulb (n = 2), th ickened wall of the vein patch (n = 2), and ICA kink (n = 7), two of w hich were associated with retained atheroma. Nine defects (14.5%) were reexplored and repaired; there were seven flaps, one residual plaque, and one case with turbulent flow alone. Results: Patients with a norm al examination result had an early ICA occlusion rate of 0.79% (n = 2) , an early stroke rate of 1.6% (n = 4), and one death (0.4%). In the u nrepaired group these rates were 1.9% (n = 1) and 1.9% (n = 1), respec tively. No occlusion occurred in the repaired group, but one preexisti ng cerebrovascular accident worsened immediately after operation. freq uency analysis and B-mode imaging were performed after operation and e very 6 to 12 months in all patients (mean 21.6 months). A greater than 75% area stenosis was found in nine (17%) of the 53 unrepaired caroti d arteries, but in only four (4.3%) of the 254 carotid arteries lackin g defects and in one of the reopened group (p < 0.001). There have bee n no late strokes, and only three late transient ischemic attacks over all. Conclusions: A normal intraoperative scanning result obtained aft er carotid endarterectomy is associated with improved late patency rat es. Even small defects appear to be associated with an increased incid ence of late restenosis, reemphasizing the importance of technical per fection.