Management of congenital hydronephrosis with ureteropelvic junction obstruction: the Vienna-AKH experience 1986-2001.

One of the most common causes of congenital hydronephrosis is obstruction of the ureteropelvic junction. The obstruction can be detected with prenatal ultrasonography screening and treated before renal function is reduced; the obstruction may also resolve spontaneously. Currently, there is no test for predicting the outcome of this obstruction. Management guidelines for neonates with asymptomatic obstruction of the ureteropelvic junction are based on expert opinions, but not on evidence-based data. In our retrospective study, we evaluated management and outcome of 26 renal units in 23 infants (15 boys, 8 girls) with congenital obstruction of the ureteropelvic junction treated in our institution between 1986 and 2001. These infants had isolated hydronephrosis on prenatal and postnatal sonography, showed an obstructive curve pattern in the postnatal diuretic nephrogram and had at least one follow-up nephrogram during a follow-up period of at least 1.5 years. Of these renal units, 16 demonstrated normal function (Group I), five moderate function (Group II) and five severely reduced function (Group III). In group I, 6 of 12 primarily conservatively managed kidneys resolved spontaneously and remained normal in function. In group II, all infants were operated and 83% improved their kidney function. In group III, all infants were operated but none demonstrated relevant improvement. These data support the current expert opinion of the Arbeitsgemeinschaft Pädiatrische Nephrologie (APN), that ureteropelvic junction obstruction in neonates with normal renal function can be managed primarily conservatively with close monitoring. In neonates with moderately--but not with severely--reduced renal function, early surgery is effective in the prevention of deterioration.