Ureteropelvic junction obstruction in infants and children.

An important question that needs to be answered in larger numbers of children is the potential recoverability of function in those followed up until function decreases. Most series involve small numbers. Some investigators claim that the function, once lost, does not return; others believe that early repair yields better improvement than does repair after 1 year. In the meantime, the authors continue to recommend a restrained interventional approach. The authors use surgical therapy early for infants with grade 3 or 4 dilatation and decreased function in the involved kidney or, overall, those with solitary kidneys or bilateral involvement. Those followed up undergo surgery if they show increased dilatation or loss of function, develop symptoms, or have dilatation that does not improve beyond the second year of life. The authors prefer to operate before there is loss of function, even at the risk of operating in a few infants that might have remained stable, because the long-term outcome of those who remain dilated is unknown and follow-up in some environments is not always reliable. Whether improved analysis of the excretory pattern on renography will prove to have prognostic value is unknown.