['Follow-up of patients undergoing dextranomer/hyaluronic acid injection for vesico-ureteral reflux (VUR) is controversial. The purpose of our study was to test the hypothesis that patients undergoing the double hydrodistention-implantation technique (Double HIT) have a higher clinical and radiographic success rate.', 'Patients undergoing Double HIT endoscopic injection for VUR were prospectively identified. Patients underwent an ultrasound at 6 weeks to assess the implants, and, if visible, prophylactic antibiotics were discontinued and patients were scheduled for a 1-year voiding cystourethrogram (VCUG). Radiographic success was defined as a negative VCUG and clinical success as no febrile urinary tract infections at 1 year.', 'A total of 54 patients underwent endoscopic injection for VUR. Twenty-five (51%) were compliant with the 1 year follow-up; 18 non-compliant patients were contacted and their clinical status assessed. Thirty patients eventually completed the 1-year VCUG at a mean of 12.2 months (range 10-20). Among the 60% of patients with 1-year radiographic follow-up, 2 had persistent VUR for a radiologic success rate of 93%. All radiographic failures were infection-free. Of the 80% (43/54) of patients with available clinical data, 3 (7%) had afebrile UTI for a clinical success rate of 93%.'] Does intermediate to long-term follow-up indicate low risk of recurrence after Double HIT endoscopic treatment for primary vesico-ureteral reflux?