Spontaneous resolution of high grade infantile vesicoureteral reflux

Purpose: We studied the spontaneous resolution rate in a group of infants with high grade vesicoureteral reflux (VUR). The influence of gender, prenatal or postnatal diagnosis, recurrent urinary tract infections (UTIs) and bladder dysfunction on the resolution rate was also evaluated. Materials and Methods: This prospective study comprised 115 infants (80 boys and 35 girls) with high grade VUR (grades III to V). Bilateral reflux was seen in 70% of cases. The majority of patients (71%) were diagnosed after UTI during infancy and only 26% were prenatally diagnosed. Median age at diagnosis was 2.7 months. Patients were followed according to a program of repeat video cystometry and noninvasive 4-hour voiding observations. Median followup was 39 months. Results: The overall spontaneous resolution rate to grade II or less for all grades was 39% with no difference between boys and girls. However, when comparing the more severe grades IV and V, we found a significantly higher resolution rate in boys during the infant year. No difference in VUR disappearance could be detected when comparing the groups according to presentation, prenatal ultrasound or pyelonephritis. Breakthrough UTIs were seen in 47% of cases despite antibacterial prophylaxis and they significantly correlated with VUR nonresolution. Bladder dysfunction was found in 37% of patients and it also significantly correlated with nonresolution. Conclusions: The spontaneous resolution rate for high grade (grades IV and V) congenital VUR was high in boys during the infant year (29%), whereas in girls and boys after the infant year the resolution rate was 9% yearly during followup. Negative prognostic factors for resolution were recurrent UTIs and bladder dysfunction.