Ureteropelvic junction obstruction in the newborn.

Ureteropelvic junction (UPJ) obstruction is a common cause of hydronephrosis in infants. Newborns with severe obstruction often have marked improvement following correction; therefore early diagnosis and operation is important. From 1973 to 1983, 21 patients were operated on for UPJ obstruction diagnosed under 6 weeks of age. Six patients (29%) had antenatal ultrasonographic diagnosis. The remaining patients were diagnosed by IVP or radionuclide scan for palpable renal enlargment or for associated anomalies. Seventeen had unilateral and four had bilateral obstruction. Twenty-three pyeloplasties, one primary nephrectomy, and one cutaneous pyelostomy with subsequent nephrectomy were done. All pyeloplasties were dismembered, with tailoring of the renal pelvis. Postoperative renal function was followed with radionuclide scan or IVP. Postoperative complications included a single urinary tract infection in three patients and two bowel obstructions. One early postoperative death occurred in an infant with bilateral obstruction who developed congestive heart failure secondary to severe uncontrollable hypertension. There were two other unrelated late deaths. Documented functional improvement with minimal complications follow unilateral or simultaneous bilateral pyeloplasty in newborns with UPJ obstruction.