CAROTID-ARTERY STENOSIS - PREOPERATIVE NONINVASIVE EVALUATION IN A COMMUNITY-HOSPITAL

Purpose: The purpose of this study was to determine whether noninvasiv e evaluation with duplex ultrasonography and magnetic resonance angiog raphy of patients with carotid artery stenosis can replace contrast an giography at our institution. Methods: This study consisted of a retro spective chart review of 40 patients (74 carotid arteries) in combinat ion with a blinded reanalysis of original data. Contrast angiography w as compared with duplex ultrasonography and magnetic resonance angiogr aphy. The overall diagnostic accuracy of duplex ultrasonography and ma gnetic resonance angiography was determined individually and concordan tly in patients being evaluated for carotid artery stenosis. Results: The overall sensitivity of duplex ultrasonography was 88.5%, and the s pecificity was 91.7% (Spearman correlation coefficient = 0.8456; p < 0 .001). For magnetic resonance angiography the sensitivity was 92.3%, a nd the specificity was 97.9% (Spearman correlation coefficient = 0.908 6; p < 0.001). In the presence of concordance, the noninvasive studies exhibited a sensitivity of 100%, (correlation coefficient = 0.9661; k appa value = 0.9655). No occlusions or severe lesions were missed by b oth studies. In only one vessel (1.52%) was a false-positive concordan ce noted. Conclusions: Carotid endarterectomy may be undertaken with a high degree of confidence that the operation will be appropriate if t he noninvasive evaluations are concordant. In the absence of concordan ce of the noninvasive studies, contrast angiography should be consider ed.