[Assessment of arterial occlusive disease with Duplex sonography. Prospective study]. / Avaliação da doença oclusiva das artérias renais com Triplex Scan. Estudo prospectivo.

Occlusive disease involving the renal arteries represent a major cause of curable hypertension and improvement of renal dysfunction. Angiography is still the major diagnostic procedure. Isotopic methods with Captopril and split-function studies have shown high incidence of false-positive and false-negative results. Colour flow Duplex-Scan renders possible the visualization of the aorta and renal arteries, is noninvasive and combines morphologic and hemodynamic evaluation. To assess its efficacy in the diagnosis of renal artery occlusive disease, a prospective blind study was undertaken in 24 patients, 48 renal arteries, 15 women and 9 men, with mean age of 44 years. Scans of the aorta and renal arteries at the origin, along its extension and at the renal hilum were obtained using and ATL Ultrmark 9 with 3.0 MHZ probe Velocity measurements were obtained at the aorta and along the renal arteries. Criteria for a positive examination were: focal acceleration with a reduction of the flow velocity at the hilum. Absence of flow in a properly visualized renal artery was considered as occlusion. All patients had digital subtraction arteriography. In 1 patient the non-invasive examination was inadequate. In the remain 23 patients the exam was considered adequate. False-positives were 4.8%; false-negatives 8.7%. Sensitivity, specificity and accuracy were respectively 91.7%, and 95.7% and 93.5%. These results suggest that non-invasive assessment of renal artery occlusive disease is feasible and accurate when compared to angiography, thus providing a useful tool for screening hypertensive patients.