Temporal Pattern of Vesicoureteral Reflux on Voiding Cystourethrogram Correlates with Dynamic Endoscopic Hydrodistention Grade of Ureteral Orifice

PurposeThe double hydrodistention implantation technique uses ureteral hydrodistention to visualize injection site(s) and determine required bulking agent volume. Along with grade, early vesicoureteral reflux on voiding cystourethrogram provides prognostic information regarding spontaneous resolution of reflux. We hypothesized that reflux timing is predictive of endoscopic hydrodistention grade.Materials and MethodsWe identified children undergoing the double hydrodistention implantation technique for primary vesicoureteral reflux between 2009 and 2012. Hydrodistention grade (0 to 3) was assigned prospectively, and compared to vesicoureteral reflux grade and timing on voiding cystourethrogram.ResultsA total of 196 children with a mean ± SD age of 3.94 ± 2.58 years underwent injection of 332 ureters. Mean ± SD vesicoureteral reflux grade was 2.8 ± 0.9. Of the ureters 52.4% demonstrated early to mid filling, 39.2% late filling and 8.4% voiding only reflux. Mean ± SD reflux grade was 3.1 ± 0.81 for early filling, 2.6 ± 0.81 for late filling and 2.1 ± 1.1 for voiding only (p <0.0001). Vesicoureteral reflux and hydrodistention grades correlated, with higher reflux grades associated with grade 3 hydrodistention (p <0.001). There was a significant relationship between reflux timing and hydrodistention grade (p <0.001), with a high percentage of ureters with grade 3 hydrodistention displaying early reflux compared to those with grade 1 disease. Significantly increased mean injected volume for ureters with grade 3 hydrodistention (1.6 ml) was observed compared to those with grade 1 or 2 disease (1.25 ml, p <0.001).ConclusionsHydrodistention grade correlates with vesicoureteral reflux grade, timing of reflux and injected volume. Early to mid filling vesicoureteral reflux is associated with abnormal hydrodistention (grade 2 to 3). Temporal pattern of vesicoureteral reflux on voiding cystourethrogram may be used to predict ureteral orifice competency and thus aid in predicting resolution of reflux.