ABSTRACT
From 1992 to 1997, 982 calculus in the upper urinary tract (UUT) was removed. There were 10 acute renal failure and 75 chronic renal failures. The study deserves special commentaries. Renal failure occurred in both groups patients bilateral calculi (group I) and calculus in the single kidney (group II). The members of chronic renal failure were much higher than that of acute renal failure. Renal failure in group II was 2.24 time higher than in group I. The risk was equal for both sex. In group I, the rate of renal failure increased with long history of disease and patients in very short time. Among high - risk factors for renal failure we noted: calculus in many location, bilateral Staghorn calculus multiple bilateral calculi or calculi with calculi in the single kidney, calculi urinary tract infection. Roentgenography, ultrasound, and radioisotope examinations were used as non-invasive techniques for those patients