Role of Doppler US in screening for carotid atherosclerotic disease

PURPOSE: To evaluate Doppler ultrasound (US) as a screening modality before arteriography for extracranial carotid artery disease. MATERIALS AND METHODS: The net benefit in stroke reduction from screening with Doppler US was calculated on the basis of literature estimates of disease prevalence, risk reduction data, and locally validated sensitivities and specificities for detection of carotid artery stenosis and occlusion in 215 patients. RESULTS: Screening a symptomatic population demonstrated a net stroke reduction. Screening asymptomatic populations with a 20% prevalence of ≥60% stenosis also yielded a net stroke reduction. Screening low-prevalence (5%) asymptomatic populations produced a small benefit, which was lost if arteriographic or surgical complications increased slightly. Arteriographic confirmation of the US diagnosis of occlusion produced a small benefit only in the symptomatic population. CONCLUSION: Screening symptomatic and high- prevalence asymptomatic populations with US reduces stroke. Increased arteriographic or surgical complication rates reduce the benefit of screening in any population.