Possible Causes of Unsuccessful Endoscopic Collagen Treatment of Vesicoureteric Reflux in Children

Objective: The purpose of this prospective study was to identify possible causes of unsuccessful treatment of vesicoureteric reflux (VUR) in children by endoscopic collagen injection. Patients and Methods: Between February 1994 and September 1996, 130 primary VURs in 94 children aged 3–16 years were treated by endoscopic injection of collagen. Grade 2 VUR was found in 46 ureteric units, grade 3 in 55, and grade 4 in 11 ureteric units. Seventy-seven children had normal micturition, and 17 showed signs of an unstable bladder. The collagen injection was performed under general anasthesia. All children had a follow-up assessment on average 5.1 months after the first injection of collagen. They were evaluated by micturition cystography and ultrasound examination of the urinary tract. Results: A single injection of collagen eliminated VUR in 74 (56.9%) cases. There was a statistically significant correlation between the grade of VUR and the success rate of collagen therapy (p < 0.01). The average amount of collagen used in cured and in noncured children was 0.55 and 0.76 ml, respectively (p < 0.01). Children with normal appearance of the ureteric orifice had significantly better results as compared with other children (p < 0.01). There was no statistically significant correlation between the success rate of treatment and the place of collagen injection or the shape of ureteric orifice following the injection. A statistically significant association, however, was found between the function of the lower urinary tract and the results of endoscopic collagen treatment for VUR (p < 0.05). Ultrasound showed no obstruction of the upper urinary tract. Conclusion: High-grade VUR, incorrect technique of injection, and voiding dysfunction seem to be some of the possible causes of an unsuccessful endoscopic collagen treatment of VUR in children.