The prognostic impact of an abnormal initial renal ultrasound on early reflux resolution

Objective: In a group of children diagnosed with vesicoureteral reflux (VUR) we evaluated renal ultrasound findings, associated findings on renal scan, and prognostic impact on VUR resolution. Methods: Medical records were reviewed for children with primary reflux and no history of antenatal hydronephrosis who underwent an initial renal ultrasound. Abnormal renal ultrasound was defined as hydronephrosis or relative difference in renal size ≥1 cm. Reflux resolution was evaluated at 2 years post diagnosis. Results: In 129 children with VUR (111 girls, 18 boys), 39 (30%) had an abnormal renal ultrasound. Two-year VUR resolution in the abnormal renal ultrasound group was 21% versus 46% in the group with normal renal ultrasound (P = 0.01). Combining grade II and III reflux, an abnormal ultrasound was associated with a statistically significantly lower resolution rate (grade II-III 23% vs 47%, P = 0.049). For children with moderate hydronephrosis, 8/9 (89%) had abnormal initial renal scans and all failed to achieve resolution of reflux at 2 years. Conclusions: In this cohort of children with VUR, 30% had abnormalities on renal ultrasound. The presence of moderate hydronephrosis on ultrasound may indicate a high likelihood of abnormality on renal scan and failure to achieve early resolution of VUR.