Children and adolescents with ureteropelvic junction obstruction: is an additional voiding cystourethrogram necessary? Results of a multicenter study

The incidence of ureteropelvic junction obstruction (UPJO) and concomitant vesicoureteral reflux (VUR) ranges from 14 to 18 %. Therefore, different guidelines recommend a voiding cystourethrogram (VCUG) to identify cases of VUR early in the diagnostic process. Aim of this multicenter study was to reassess the incidence of concomitant VUR and the need for additional VCUG in a large cohort of patients with UPJO. Furthermore, we asked for clinical objectives that defined the need for VCUG with the intention of minimizing radiation exposure and the need for invasive diagnostic procedures. Medical records for 266 patients (69 girls, 197 boys) with UPJO were analyzed retrospectively. Data were obtained on gender, clinical symptoms, results of pre- and postnatal ultrasound, VCUG and 99(m)Technetium-MAG3 (MAG3) scan. They were correlated with the incidence of concomitant VUR. One hundred and seventy-eight patients (67 %) underwent VCUG. Concomitant VUR was detected in 13 patients. Dilating VUR (dVUR) was observed in 11 patients. In our study, the overall incidence of a concomitant VUR was 7.3 %. In cases of proven VUR, we observed a positive predictive value for female gender, ureteral dilatation, renal insufficiency, and recurrent urinary tract infections (UTI). But there was no correlation between concomitant VUR and the severity of hydronephrosis. Our data suggest that the low incidence of concomitant VUR in cases of UPJO does not justify the routine use of VCUG as a routine diagnostic tool. Especially, ureteral dilatation and recurrent UTI have a positive predictive value for concomitant VUR.