The Role of Initial Relative Renal Function in Unilateral Hydronephrosis

Purpose: The information on the change of the relative renal function after operation is essential to set the initial treatment plan in unilateral hydronephrosis. So we analyzed the preoperative and postoperative relative renal function, and observed the functional changes by operation and reliability of the various factors in those changes. Materials and Methods: A retrospective trial was done of 81 patients, 35 ureteropelvic junction(UPJ) obstruction and 46 vesicoureteral reflux(VUR), among 393 patients undergoing operations at our institution from March. 1992 to February. 1997. The patients who had infravesical abnormalities, abnormal contralateral kidney and insufficient research data were excluded. We determined the relative renal functions using DTPA and MAG3 scan in UPJ obstruction and DMSA scan in VUR. The mean observation period after operation was 2.01(0.25-4) years. Results: A. UPJ Obstruction 1. The relative renal function was improved significantly after operation(P=0.0007). 2. The kidneys which have preoperative functions between 20% and 40% improved significantly in relative renal function comparing to the kidneys of the other functions(P=0.0046). B. VUR 1. The renal functions didn't improve significantly after operation(P>0.05). 2. There was no significant factor affecting the prognosis in renal functions. Conclusions: 1. The kidneys with UPJ Obstruction show the difference in functional improvement after operation according to the degree of the preoperative renal function, but more investigations about the exact value are needed. 2. In VUR there was no difference between preoperative and postoperative functions, the theoretical basis on objectives of the operation could be the symptoms or factors except the operation.ope