RENAL HEMODYNAMICS IN PATIENTS WITH OBSTRUCTIVE UROPATHY EVALUATED BYCOLOR DOPPLER SONOGRAPHY

Objectives: Prior animal studies have shown through direct pressure me asurements that there is a definite rise in the renal vascular resista nce in obstruction. Therefore intrarenal. hemodynamic changes can be d etermined by the vascular impedance expressed as pulsatility and resis tive indexes (PI and RI) obtained from the Doppler waveforms of intrar enal arteries. We investigated whether various degrees of obstruction result in different hemodynamic responses according to color Doppler s onography. Methods: 22 kidneys with varied degrees of hydronephrosis a nd 19 normal kidneys were examined. The pulsatility and resistive inde x of Doppler waveforms from interlobar arteries were obtained. The gra de of hydronephrosis was based upon the width of parenchyma. Results: The mean resistive index in the study and controls were 0.70 +/- 0.07 and 0.60 +/- 0.03, respectively. The difference was significant (p < 0 .001). Pulsatility indexes in the study and controls were 1.07 +/- 0.3 4 and 0.98 +/- 0.23, respectively. The difference was not significant (p > 0.005). Significant difference was also noticed in the parenchyma l widths between both groups (p < 0.001). Conclusion: It appeared that intrarenal color Doppler sonography can provide physiologic informati on reflecting renal vascular resistance status by means of an easily o btained parameter: resistive index.