Postoperative ureteral obstruction after endoscopic treatment for vesicoureteral reflux

PURPOSE We undertook this study to evaluate the incidence, risk factors, management, and outcome of postoperative ureteral obstruction after endoscopic treatment for vesicoureteral reflux (VUR). MATERIALS AND METHODS Ninety patients undergoing endoscopic treatment for VUR were retrospectively reviewed and classified into two groups according to ureteral obstruction: the nonobstruction group (83 cases, 122 ureters; mean age, 7.0 ± 2.8 years) and the obstruction group (7 cases, 10 ureters; mean age, 6.2 ± 8.1 years). We analyzed the following factors: age, sex, injection material, laterality, voiding dysfunction, constipation, renal scarring, preoperative and postoperative ultrasound findings, endoscopic findings, injection number, and injection volume. Additionally, we reviewed the clinical manifestations, natural course, management, and outcome of ureteral obstruction after endoscopic treatment. RESULTS The incidence of ureteral obstruction after endoscopic treatment was 7.6% (10/132 ureters). The type of bulking agent used and injection volume tended to be associated with ureteral obstruction. However, no significant risk factors for obstruction were identified between the two groups. Three patients showed no symptoms or signs after the onset of ureteral obstruction. Most of the patients with ureteral obstruction experienced spontaneous resolution within 1 month with conservative therapy. Two patients required temporary ureteral stents to release the ureteral obstruction. CONCLUSIONS In our experience, the incidence of ureteral obstruction was slightly higher than in previous reports. Our study identified no predictive risk factors for developing ureteral obstruction after endoscopic treatment. Although most of the ureteral obstructions resolved spontaneously within 1 month, some cases required drainage to relieve symptoms or to prevent renal function deterioration.