Optimising the use of carotid duplex sonography

Aim: We analysed factors influencing diagnostic yield and treatment and the ir potential for optimising the use of carotid duplex sonography (CDS). Method: Patients referred for CDS were divided into three groups: 1: high l ikelihood of carotid symptoms, 2: suspected presence of asymptomatic caroti d lesions, 3: other indications. Clinical data, the grading of stenosis and the therapeutic consequences were analysed. The efficiency of diagnosis wa s tested with an algorithm. Results: 344 patients were included, Groups 1, 2 and 3 contained greater th an or equal to 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 va scular disease were associated with a significantly higher diagnostic yield . Subsequent treatment in groups 1, 2 and 3 involved carotid thromboendarte rectomy 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 optimi sation 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 cho sen for asymptomatic stenoses and secondary prophylaxis.