Vesicoureteral reflux: the RIVUR study and the way forward.

C ommon clinical practice has been that all children who present with a urinary tract infection (UTI) must be evaluated for vesicoureteral reflux with a voiding cystourethrogram (VCUG). The etiological association between reflux and infection was assumed since up to 40% of children with infection are found to have reflux. Evidence from the 1960s appeared to demonstrate that the diagnosis and treatment of reflux were necessary to prevent further infection and renal scarring from pyelonephritis. This literature is now being questioned, and conventional diagnostic and therapeutic recommendations are being challenged. Some specialists now allege that the radiographic detection of reflux is not necessary in all children after an infection. Furthermore, when reflux is detected the recommendations for treatment are controversial and contradictory. Depending on the consultant a child with reflux may be placed on long-term antibiotic prophylaxis, observed off prophylaxis, or undergo surgical procedures such as cystoscopic Deflux® injection, or open intravesical, extravesical or laparoscopic ureteral reimplantation. Pediatric urologists have been basing recommendations on 3 decades of poorly controlled studies. These studies suggest that episodic treatment of infections in patients with known reflux results in unacceptably high rates of new renal damage. These older studies were not blinded or well controlled, they relied on excretory urograms to detect scarring instead of radionuclide imaging, and did not use the International Classification System. The few prospective studies that were controlled compared surgery to continuous prophylaxis such as the International Reflux Study or the Birmingham Cooperative Study, but did not have an observation arm. Cooper and Thompson et al prospectively observed children with reflux on and off prophylaxis, and found similar rates of infection. However, in these 2 studies scarring was often assessed by renal ultrasound rather than dimercapto-succinic acid (DMSA) renal scans, and voiding function was not routinely or prospectively measured. Recently Garin et al reported on a small group of children with reflux off prophylaxis, and after 1 year the infection rate was similar to that of children on medication. Rates of renal disease secondary to reflux remained unchanged for 3 decades in an Australian study, suggesting that the identification and treatment of reflux have not reduced the incidence of clinically significant reflux nephropathy. In a recent meta-analysis only 8 randomized, controlled trials of children with reflux could be found, 1 of which compared prophylaxis to placebo. This small trial did not find an increased risk of renal scarring in children observed off prophylaxis. The authors of the meta-analysis concluded that properly designed placebo controlled trials