Prospective Study of Polydimethylsiloxane vs Dextranomer/Hyaluronic Acid Injection for Treatment of Vesicoureteral Reflux

Purpose: Endoscopic injection of a bulking agent is becoming a first-line treatment for low grade vesicoureteral reflux. We prospectively compared the efficacy of 2 such products commercially available in Canada. Materials and Methods: A total of 275 patients with documented grade I to V vesicoureteral reflux were prospectively enrolled in a comparative study between April 2005 and February 2011 to be randomly treated endoscopically with either polydimethylsiloxane (Macroplastique (R)) or dextranomer/hyaluronic acid copolymer (Deflux (R)). Of the ureters 202 were treated with polydimethylsiloxane and 197 with dextranomer/hyaluronic acid copolymer. Patients were followed with voiding cystourethrography at 3 months and renal ultrasonography at 3 months and at 1 year. Median followup was 4.3 years. The primary outcome was surgical success (resolution vs nonresolution), and secondary outcomes included occurrence of adverse events. Results: Vesicoureteral reflux was fully corrected in 182 of 202 ureters (90%) treated with polydimethylsiloxane, compared to 159 of 197 (81%) treated with dextranomer/hyaluronic acid copolymer (p < 0.05). Obstruction was found in 5 ureters. Univariate and multivariate analyses did not allow identification of any characteristics that could explain the significant difference in the success rates except for the type of product used. Conclusions: We present the largest known prospective evaluation comparing 2 bulking agents for the treatment of vesicoureteral reflux. Endoscopic injection of polydimethylsiloxane resulted in a better success rate than dextranomer/hyaluronic acid copolymer. The rate of resolution obtained with the latter is lower than those previously published due to the inclusion of high grade reflux.