What are the factors affecting the mound displacement detected in endoscopic treatment failure of vesicoureteral reflux

INTRODUCTION: Success rates of endoscopic treatment for vesicoureteral reflux range from 50-100%. Various factors predict outcomes after endoscopic injection. Mound displacement is one of the most critical factors for failure.We observed mound displacement in most of the patients with endoscopic injection failure. We aimed to evaluate predisposing factors for mound displacement in patients with endoscopic injection for vesicoureteral reflux.
METHODS: In 2020, operative images were taken and archived in cases where the endoscopic injection was applied due to vesicoureteral reflux. The localization of the bulking agent was evaluated during the redo procedure in 11 patients who were re-admitted due to the failure of the injection procedure. In addition, age, gender, side and degree of reflux, bladder thickness in US, and bladder trabeculation were evaluated.
RESULTS: Local migration of bulking agent was seen in 11 patients at cystoscopy after initial treatment failure. Our repeat endoscopic injection rate was 11/80 (13.75%). Bladder wall thickness and/or trabeculation, constipation, and post-voiding residue (over 20 ml) were significantly higher in patients with mound displacement.
DISCUSSION AND CONCLUSION: Patients with thick bladder walls with increased PVR and accompanying constipation have the risk of mound displacement. Therefore, we recommend performing a cystoscopy in all cases with recurrence to evaluate the location of the bulking agent. If the mound displacement is noted, we recommend reinjection. Patients with a thick bladder wall, postvoiding residue, and concomitant constipation are at increased risk of bulking agent displacement. If migration of bulking agent is detected, we recommend reinjection with Double HIT or multi-site injection techniques.