[Duplex Doppler ultrasound value in upper urinary tract obstruction ].

UNLABELLED: Our prospective study aimed to establish the duplex Doppler ultrasonography (DDU) value in patient's investigative protocol with acute or chronic ureteral obstruction. A. DDU IN ACUTE URETERAL STONE OBSTRUCTION: Between October 1988 and January 2001 we applied DDU evaluation for 177 cases with ureteral lithiasis in which we also studied gray scale echography, resistive index (RI), the difference between affected kidney and contralateral kidney (delta RI) and the characteristics features (amplitude, velocity and frequency) of the ureteral jets (intravesical evaluation in color Doppler mode). a. For 65 cases with RI < 0.70, delta RI < or = 0.06 we didn't find obstruction and 95.4% of the patients had spontaneous passage of the stones. b. For 109 cases with RI > 0.70, delta RI > or = 0.06 the spontaneous passage of the stone was found in 40 cases (36.7%). DDU associated with ureteral jet evaluation increased the predictive value of this method. So, the presence of the ureteral jet on the obstructed side of the upper urinary tract was associated with 63% of spontaneous passage of the stone while the absence of the jet was followed by 5% of spontaneous passage of the stone. The RI was sensitive in 74% and specific in 81% and delta RI was sensitive in 85% and specific in 91%. B. DDU IN CHRONIC URETERAL OBSTRUCTION: Between October 1988 and January 2001 we evaluated the DDU value in chronical ureteral obstruction on 78 cases with operated and/or irradiated genital neoplasm's and retroperitoneal involvement. Our results found RI sensitive in 63% and specific in 70% and delta RI was sensitive in 72% and specific in 78%. After double J stenting (indwelling) RI varied from 0.74 to 0.66 (0.08), with a significative decrease (over 10%) in 61.5% of the cases in which preoperator RI was greater than 0.70. After 1 month we found an increase of RI with 0.02 and after 3 months with 0.05.

IN CONCLUSION: We consider DDU a functional imagistic method with an important place in the investigative protocol of the obstructive uropathy.