NATURAL-HISTORY OF PELVIURETERIC OBSTRUCTION DETECTED BY PRENATAL SONOGRAPHY

Summary— Fifty‐six infants with prenatally diagnosed hydronephrosis are reported. In all instances the diagnosis was confirmed postnatal and at renography 45 were obstructed; 38 obstructed kidneys (84%) and all of the non‐obstructed kidneys had a differential function exceeding 40% of total function. Latterly we have come to recommend early pyeloplasty only if differential function of a renographically obstructed kidney is less than 40%; 6 early pyeloplasties were performed for this reason; 28 infants (30 renal units) were managed non‐operatively and 18 of these (19 renal units) were reassessed renographically. In 11 the obstruction persists. Sonography demonstrated improving hydronephrosis in 8 kidneys with resolution in 5 and no change in 6. Of the other 10 infants (11 renal units), the hydronephrosis has improved in 4, resolved in 1 and remains unchanged in 6. Our experience suggests that neonatal and early pyeloplasty can be restricted to a modest number of infants in whom there is impaired renal function. In cases with normal function the natural history appears essentially benign and does not justify routine pyeloplasty. © 1990 British Journal of Urology