Polyacrylamide Hydrogel as a Bulking Agent for the Endoscopic Treatment of Vesicoureteral Reflux: Long-Term Results and Safety

Abstract

Polyacrylamide hydrogel has been shown to offer good short-term success for the endoscopic treatment of vesicoureteral reflux. Our objective was to provide long-term results of its efficacy and safety. We performed a prospective study using polyacrylamide hydrogel to treat all grades of vesicoureteral reflux. Every patient underwent endoscopic injection of polyacrylamide hydrogel followed by 3-month postoperative renal ultrasound and voiding cystourethrogram. Renal ultrasound was repeated at 12 and 36 months. Treatment success was defined as the absence of de novo or worsening hydronephrosis and the absence of reflux. Safety elements included new or worsening hydronephrosis, calcifications of the injected material and urinary tract infections. A total of 76 patients (123 refluxing renal units) were assessed. Median age at surgery was 45 months and median followup was 36 months. Median injected volume of hydrogel per refluxing renal unit was 1.0 ml. The overall success rate 3 months after a single injection was 71%. During long-term followup 68 of 70 eligible patients underwent 12-month ultrasound and 40 of 46 underwent 36-month ultrasound. No upper tract deterioration or bulking agent calcifications were reported. Nine (12%) and 2 patients (3%) presented with nonfebrile and febrile urinary tract infections, respectively. The success rate of polyacrylamide hydrogel for endoscopic treatment of vesicoureteral reflux is comparable to published results of dextranomer hyaluronic acid. The long-term safety data and potential lower cost of polyacrylamide hydrogel provide further support for the use of this nonparticulate bulking agent to treat reflux.