Preoperative IVU revealed good renal function in 46 cases (97.9%), mediocre renal function in 1 (2.1%), 17 cases with no hydronephrosis (36.2%), 17 cases with mild hydronephrosis (36.2%), 10 cases with moderate hydronephrosis (21.3%), and 3 cases with severe hydronephrosis (6.4%).