Pediatric pyeloplasty: is routine retrograde pyelography necessary?

To evaluate the necessity for retrograde pyelography in the preoperative evaluation of children undergoing pyeloplasty, we reviewed the records of 108 consecutive patients (age range 5 days to 18 years, median 1 year) who underwent pyeloplasty at our institution during a 6-year period. The routine preoperative evaluation consisted of a renal/bladder sonogram, furosemide renal scan (99mtechnetium-diethylenetriaminepentaacetic acid or 99mtechnetium-mercaptoacetyltriglycine) and voiding cystogram. No other imaging studies were obtained in 95 patients (88%). Other upper tract studies usually performed before referral included excretory urography in 9 cases and computerized tomography in 5. Preoperative retrograde pyelography was only performed in 1 symptomatic patient before referral to our institution. Surgical findings confirmed obstruction at the ureteropelvic junction in all patients. Undetected ureteral dilatation, which might suggest undiagnosed distal obstruction, was not encountered. After pyeloplasty 2 patients were lost to followup, renal drainage improved in 104 (98%) and drainage failed to improve in 2 of whom 1 (0.9%) required reoperation. All patients who presented with symptomatic uretero-pelvic junction obstruction experienced postoperative resolution of the presenting complaints. Our series demonstrates that routine retrograde pyelography to define the level of obstruction is not necessary for successful primary pyeloplasty. In experienced hands and with careful attention to detail, the combination of renal/bladder sonography and diuretic renography can reliably exclude the possibility of distal obstruction in children with hydronephrosis before pyeloplasty.