Resolution rates of low grade vesicoureteral reflux stratified by patient age at presentation

Purpose: Most children with grades I to III primary vesicoureteral reflux are monitored for years on antibiotic prophylaxis until reflux resolves. While the overall resolution rate of these grades is known, the rates for various patient ages at presentation are unknown. Therefore, we examined resolution rates of these grades for different ages at presentation. Materials and Methods: From 1985 through 1990, 168 boys (245 ureters) and 433 girls (590 ureters) with all grades of reflux were enrolled in the study and monitored through the end of 1993. Urine cultures were obtained every 4 months and contrast voiding cystourethrography was repeated every 18 months. Age at presentation was stratified into groups younger than 1, 1 to 3, 4 to 6, 7 to 9, and 10 years and older. Resolution rates were then calculated for grades I to III reflux for each age at presentation. Time to resolution was also evaluated for each age and grade. Results: There were no significant differences between rates of resolution at different ages for each grade. Children less than 10 years old had as high a likelihood of resolution as infants. Neither sex nor bilaterality versus unilaterality was a helpful predictor of resolution. Time to resolution varied widely and it was also not helpful for identifying the cases of reflux that resolved. Conclusions: Low grade vesicoureteral reflux may not resolve until adolescence and age at presentation is not a reliable predictive factor. Children should remain on prophylaxis for many years unless definitive correction is undertaken.