The importance of follow-up of children with vesicoureteral reflux grade 1.
AIM: The objectives of this study were, first, to determine the probability of detecting vesicoureteral reflux (VUR) into the renal collecting system (VUR grade 2 or higher) by follow-up cyclic radionuclide cystography (CRC) in children with VUR 1 on initial examination, and in children without VUR and with the same clinical history; and secondly, to find out whether dividing VUR 1 into three subclasses, including possible reflux into the ureter, reflux into the lower ureter, and reflux into the whole length of the ureter, enhances detection of higher grade reflux in these children. METHODS: 275 children with VUR 1 found on initial CRC, and 31 children without reflux and with the same clinical history were studied. In total, 414 renal units with VUR 1 of different subclasses and 198 renal units without reflux were evaluated. RESULTS: Follow-up CRC disclosed reflux into the renal collecting system in 20% of children with VUR 1 on initial investigation, and in 23% of children with no reflux at the time of initial investigation. The probability that follow-up examination would disclose VUR 2 in 3 in renal units with different subclasses of grade 1 reflux was 8-16%, and did not differ significantly from the probability for detecting reflux in kidneys with no reflux on initial examination. CONCLUSION: In the absence of recurrent urinary tract infection, the management of children with VUR 1 identified by CRC can be the same as in children without reflux. Yet, in children with no reflux or with VUR 1 detected after urinary tract infection, the probability that reflux reaching the pylon was missed should not be underestimated. Dividing VUR 1 into subclasses does not seem to be of diagnostic value.