Natural history of vesicoureteral reflux associated with kidney anomalies.

Objectives: To evaluate the cystographic follow-up of patients with multicystic dysplastic kidney (MCDK), renal agenesis, and renal ectopia with associated primary vesicoureteral reflux (VUR).

Methods: Patients with primary associated VUR (grade 2 or more) and with a minimal follow-up of 24 months were included in this study.

Results: Of the children with renal agenesis, 24% had VUR. The median grade of VUR was significantly greater in the boys than in the girls (4 versus 2, respectively; P < 0.05). All girls and 34% of the boys experienced spontaneous resolution 1 year after diagnosis; 66% of the boys required operative treatment. Of the patients with MCDK, 16% had VUR. The median grade of VUR in the kidney contralateral to the MCDK was greater in the boys than in the girls (3.5 versus 2, respectively; P = 0.06). All girls and 60% of the boys had spontaneous resolution 1 year after diagnosis; 40% of the boys underwent operative treatment. Of the children with renal ectopia, 30% had VUR. The median grade of VUR for the refluxing unit was significantly greater in the girls than in the boys (3 versus 2, respectively; P < 0.05). Spontaneous resolution of VUR was observed in all boys (66% at 1 year) and in 40% of the girls; 60% of the girls required operative treatment.

Conclusions: Spontaneous resolution of VUR can be anticipated in girls with MCDK or renal agenesis and in boys with renal ectopia. These data can be used in planning the proper follow-up schedule for babies with a kidney anomaly detected by ultrasonography.