[Renal duplex: clinical usefulness]. / Duplex renal: utilidad clínica.

It is the purpose of this report to focus attention on the clinical usefulness of Renal Duplex for the diagnosis of patients with vasculo-renal diseases in terms of: 1. Accuracy of Duplex/Angiography in the measurement of the renal stenosis degree. 2. Correlationship between Duplex ans Isotopic Renogram with respect to the study of the parenchyma's perfusion. 3. The effect of the inhibitors of the conversor enzyme (Captopril) on the Doppler signal of the parenchyma, comparing it with the results from the captopril test about the peripheral plasmatic renin activity and the isotopic renogram, in patients with vasculo-renal HTA. Results obtains by Duplex and Angiography were compared in 92 renal arteries from 46 patients. For both technics, three degrees of stenosis were established: 0-59%, 60-99% and occlusion. The Duplex technique identified 49/54 stenosis < 60%, 28/33 stenosis > 60% and 5/5 occlusions (Kappa 0.8). Sensibility and specificity of Duplex for the diagnosis of stenosis > 60% were, respectively, 89.5% and 90.7%; with an exactness of 90.2%. The angiographies showed stenosis > 60% in 23 patients with HTA (diastolic pressures > 100 mmHg). In all of the patients, a measurement of the plasmatic renin activity, an isotopic renogram and a Doppler of the interlobar arteries basal and post-captopril, were performed. The correlationship between Duplex and isotopic renogram with respect to the measurement of the relative renal perfusion was statistically significant (r = 0.91; p < 0.0001). The captopril test for renin and isotopic renogram were positives for 5 patients (4 with unilateral stenosis an 1 with bilateral stenosis). All of them showed severe stenosis (> 80%).(ABSTRACT TRUNCATED AT 250 WORDS)