Efficacy of Bladder Ultrasound in Prediction of Resolution of Vesicoureteral Reflux after Endoscopic Subureteral Hyaluronic Acid/Dextranome (Deflux®) Injection

Abstract BACKGROUND: We evaluated the efficacy of bladder ultrasound to predict resolution of vesicoureteral reflux after subureteral endoscopic Hyaluronic acid/dextranome (Deflux) injection.METHODS: Between 2010 and 2018, 120 patients (220 ureters) underwent Subureteral Deflux injection for reflux in children. Male/female ratio was 1: 5. All patients had voiding cystourethrography and bladder ultrasound at 3 months and one year after surgery. Outcome analysis included: Success rates and presence/ absence of Deflux mount by bladder ultrasound. RESULTS: Mean follow-up was 48 months. Mean age at surgery 72 months. Grades of reflux were grade II in 100 ureters (45.4%), III in 90 ureters (41%) and IV-V in 30 ureters (13.6%). Bilateral surgery was performed in 40 patients. Single Deflux injection cured reflux (Success rate) in 85% (187 ureters) at 3 months which improved to 88.2% (194 ureters) at last follow-up. Ultrasound was able to detect Deflux mounts at the base of the bladder in 200 ureters (91%). Sensitivity and specificity of ultrasound was 92.68% and 20% of the correction of reflux at the last follow up. Positive Predictive Value of bladder ultrasound was 94 % and accuracy was 87.7 % at the last follow up. Ultrasound did not detect the mount in 20 ureters (9 %) and 8 of these ureters (3.6%) had persistence of their reflux. Ultrasound was able to detect bilateral mounts as well as unilateral mounts.CONCLUSION: Bladder-US was highly sensitive for detection of Deflux implants and can predict resolution of reflux in 82.7% of refluxing ureters. Postoperative bladder-US could be adjusted as a screening tool in the follow-up of patients with primary low-grade VUR patients treated by Deflux injection, while VCUG could be preserved for follow-up of high-grade VUR patients.