Duplex ultrasound screening for carotid arteriosclerotic disease in asymptomatic patients.

Duplex carotid sonography was performed on 254 asymptomatic patients over the age of 55, yielding 500 adequate vessel examinations. Overall, 19.8 per cent of vessels were normal, 27 per cent had mild disease (less than 30 per cent diameter stenosis), 23 per cent had 30-49 per cent stenosis, 18.8 per cent had 50-69 per cent stenosis, 8.6 per cent had severe stenosis of 70-99 per cent, and 2.8 per cent of vessels were occluded. Many of the patients eventually underwent major surgical procedures and there were no cases of operative or perioperative morbidity or mortality. Only one of 254 patients has had a stroke in the two-year study period. Arteriosclerotic disease is common in patients over 55 years of age, but, in this series, does not seem to be of clinical significance. This supports the view that invasive tests and carotid endarterectomy should be reserved for symptomatic patients. Duplex sonography is an excellent noninvasive method of evaluation and follow-up of asymptomatic patients, and long-term studies with this modality should help to determine the natural history and clinical significance of extracranial carotid arteriosclerotic disease.