Primary vesicoureteral reflux: influence of age, laterality and grade of reflux on spontaneous resolution

Abstract

PURPOSE: We examined spontaneous resolution rates in 359 cases with primary vesicoureteral reflux (VUR). Effects of age, laterality and grade of reflux on resolution rate were evaluated.
MATERIALS AND METHODS: Subjects comprised 359 children (239 boys, 120 girls) with primary VUR. Bilateral reflux was seen in 53.2% of cases. Patients were followed-up through a program of repeat voiding cystourethrography (VCUG) observations. Cases with surgical intervention were excluded. Resolution rates were determined for 322 ureters. We evaluated the influence of age, laterality and grade of reflux on the resolution rate.
RESULTS: The spontaneous resolution rates for grade III or less, grade IV and grade V were 72%, 58%, and 40% respectively at the age of 5 years. No significant difference in VUR disappearance could be detected between unilateral and bilateral reflux, but for grade II or less the resolution rate in cases with unilateral reflux tended to be higher than that in cases with bilateral reflux.
CONCLUSIONS: The spontaneous resolution rate for low grade (grades III or less) primary VUR was 72% at the age of 5 years and it seemed that we can expect spontaneous resolution to occur over several years of age.