Vesicoureteral reflux (VUR) is believed to predispose patients to pyelonephritis, recurrent UTI, and renal scarring-a concept that has become the basis for using urinary antibiotic prophylaxis to treat VUR. Controlled studies are lacking to support the VUR-UTI association and the utility of prophylactic therapy, however, so investigators designed one.   

Patients with acute pyelonephritis, with or without mild or moderate VUR, were divided into two groups: One received urinary antibiotic prophylaxis (with either trimethoprim-sulfamethoxazole or nitrofurantoin) and one did not. Subjects, who were treated at four centers in Florida, Chile, and Spain, ranged in age from 3 months to 18 years. The 218 subjects who completed the study were monitored every three months for one year. Urinalysis and urine culture were performed at each clinic visit, and dimercaptosuccinic acid (DMSA) renal scans were repeated at six months or when a febrile UTI recurred. At the end of the one-year follow-up, renal ultrasonography and voiding cystourethrography were repeated. 

Most subjects, regardless of assignment, did not have another UTI; overall incidence of UTI after pyelonephritis was 20.1%. The most common type of UTI was cystitis. Recurrence patterns of UTI did not differ between subjects with VUR and those without VUR. Moreover, the rate of recurrence of acute pyelonephritis was low after one year of follow-up, and VUR did not appear to have an overall effect on its development. Furthermore, antibiotic prophylaxis did not affect the incidence of renal scarring.  

Our management of VUR is based more on tradition than on science; I give these investigators credit for trying to fill this evidence void. I believe, however, that their study will need to be repeated, on a larger scale and over a longer period, before we can relieve ourselves of that tradition. But this is a start.