Optimising the use of carotid duplex sonography.

AIM: We analysed factors influencing diagnostic yield and treatment and their potential for optimising the use of carotid duplex sonography (CDS). METHOD: Patients referred for CDS were divided into three groups: 1: high likelihood of carotid symptoms, 2: suspected presence of asymptomatic carotid lesions, 3: other indications. Clinical data, the grading of stenosis and the therapeutic consequences were analysed. The efficiency of diagnosis was tested with an algorithm. RESULTS: 344 patients were included. Groups 1, 2 and 3 contained > or = 1 pathological finding in the carotid or vertebral system in 68%, 86% and 55% respectively, whereas high-grade stenoses or occlusions of the internal carotid artery (ICA) were detected in 10.8%, 16% and 3.6% respectively. Age > 50, > 1 risk factor, carotid murmur and concomitant vascular disease were associated with a significantly higher diagnostic yield. Subsequent treatment in groups 1, 2 and 3 involved carotid thromboendarterectomy in 6.4%, 2% and 0.7% respectively and the start of treatment with a platelet aggregation inhibitor in 9%, 30% and 17% respectively. The optimisation algorithm would have saved 21% of CDS scans. CONCLUSION: Clinical pre-selection criteria determine the diagnostic yield of CDS. The potential for optimisation depends on the treatment regimen chosen for asymptomatic stenoses and secondary prophylaxis.