The natural history of reflux in the lower pole of duplicated collecting systems: a controlled study.

Thirty two children with reflux into the lower pole of duplicated collecting systems, followed non-operatively for one to five years, were compared to a carefully selected control group of similar children who had reflux into a single collecting system. There were no significant differences between the two groups, either in the outcome of reflux or in the incidence of new renal scars. We conclude that reflux into the lower pole of a duplex kidney does not in itself constitute an indication for early surgical treatment.