[Spontaneous resolution of reflux in children with primary VUR]

Although the adverse effects of vesicoureteral reflux on the renal function and renal growth have been well documented, there is still controversy regarding the factors for spontaneous cure of reflux and the time required for the resolution. We performed a retrospective analysis of 829 ureters in 541 children who have been followed for more than 3 years since 1973. Reflux was judged as spontaneously cured only after 2 micturition cystourethrograms (MCU) had shown no reflux. In total reflux resolved in 220 ureters (26.5%) of 182 children (33.6%). Resolution rate was 39.5% in boys and 28.0% in girls, and there was statistically significant difference between both sexes. In children who had underwent urethrotomy on congenital urethral stenosis, e.g. bulbous urethral stenosis in the boy and distal urethral stenosis in the girl, resolution rate was 43% in boys and 23% in girls. Resolution rate according to VUR-grade was 85.5% in grade I and II reflux, 45.8% in grade III, and 6.7% in grade IV and V. Of 92 children who underwent urodynamic evaluations, 37% showed findings of unstable bladder. Renal scarring was observed in 7.3% of renal units which was significantly less frequent than the incidence among total renal units with reflux. Reflux was resolved in 30% of renal units without scarring and 10% of renal units with scarring. The incidence of small kidney in the spontaneously resolved group was 3.6%, which was significantly lower compared to the total renal units with reflux. The mean age at resolution of reflux was 5.7 years in boys and 7.5 years in girls.(ABSTRACT TRUNCATED AT 250 WORDS)