Children with febrile urinary tract infections should be evaluated with voiding cystourethrography and renal sonography, but it is unclear whether repeat ultrasonography is necessary. Lowe and associates attempted to determine the usefulness of performing follow-up ultrasonography in patients with documented primary vesicoureteral reflux and normal results on the initial ultrasound examination in otherwise healthy children.

Using a computerized scheduling database, the authors identified 64 children one month to 10 years of age with vesicoureteral reflux, who were scheduled for follow-up renal sonography. These 128 “renal units” (each renal unit signified one kidney) were normal on initial sonography and on follow-up, with the time from initial sonogram to last follow-up sonogram ranging from four months to slightly more than five years. The majority (81.3 percent) of the children had been treated with antibiotics. About two thirds (65.6 percent) of reflux cases resolved spontaneously, and about one third (34.4 percent) resolved with surgical intervention.

Concern about renal parenchymal scarring in children with vesicoureteral reflux has led to the recommendation for long-term antibiotic prophylaxis, which may explain why, in this 22-month study, renal sonography remained normal in all children, regardless of whether they had spontaneous or surgical resolution or recurrent infections.

The authors conclude that follow-up renal sonography serves little, if any, clinical purpose. These findings apply only to patients with mild- to moderate-grade reflux.