RESUMEN
Duplex scanning of the extracranial carotid vessels is a highly reliable medical investigation for identifying atherosclerotic or other pathology in this vascular region. The introduction of this technique into hospital practice has posed the problem of when it is indicated. The present study has shown that almost half the examinations carried out (45.2%) were requested on the basis of what were defined as "general" symptoms (vertigo, lipothymia, migraine, etc.); this group showed a low prevalence of atheromatous plaques. 22.7% of the examinations were requested as a control in the presence of atherosclerosis in another vascular region (coronaries, arteries of the lower extremities, etc.) and in these patients the prevalence of carotid stenosis was high or very high. Patients examined subsequently to a neurological episode came to 15.3% of the total. There was a high prevalence of carotid atheromatous lesions. Numerous controls were requested in subjects with type 2A and 2B hyperlipoproteinaemia (6.7% of the total) with a prevalence of atheromatous lesions higher than the homogeneous-for-age group. A limited number of patients (2%) underwent the study following visual disturbances of presumable ischaemic origin. The prevalence of carotid stenoses in these subjects is high. Patients who underwent carotid TEA (8.1%) represent a special group in whom intervention brings a general improvement although the percentage of vessel restenosis exceeds 20%.