Long-term outcome of kidneys with initially poor drainage or no drainage following pyeloplasty

Pyeloplasty for congenital ureteropelvic junction (UPJ) obstruction enjoys a 90-95% success rate. Although treatment of the failed pyeloplasty has been addressed in the literature, management of the poorly draining or nondraining renal unit in the immediate postoperative period has not received any attention. For this purpose the medical records of 33 consecutive children (37 renal units) treated by dismembered pyeloplasty between 1986 and 1992 were reviewed. All of our pyeloplasties were stented and urine was diverted via a nephrostomy tube. All patients underwent a nephrostogram following stent removal 1 week postoperatively. These studies showed poor drainage, or no, across the newly reconstructed anastomosis in 7 of 37 renal units (19%). The ages of these 4 boys and 3 girls at the time of pyeloplasty ranged between 7 weeks and 5 years (mean 22 months). In four patients, good drainage occurred without intervention by 2-4 weeks postoperation. In two patients, percutaneous balloon dilation of the anastomosis via the intraoperatively placed nephrostomy tube was required at 3 and 6 weeks, respectively. The remaining patient failed percutaneous dilation, necessitating a ureterocalycostomy at 9 weeks following pyeloplasty. The long-term follow-up for the entire group of 33 children averaged 30 months and consisted of radionuclide diuresis renography in 84% of cases or intravenous pyelography in the remainder. All patients had excellent long-term outcomes as assessed by comparison of the postoperative studies with the baseline studies obtained preoperatively. Our results show that kidneys with initially poor drainage, or even no drainage, across the newly reconstructed anastomosis following pyeloplasty can be salvaged with an excellent long-term outcome comparable with that of the group with initially good drainage. In addition, intervention was necessary in only 43% of renal units with initial compromise and was facilitated by the intraoperatively placed nephrostomy tube. We recommend that percutaneous dilation be done at between 4 and 6 weeks postpyeloplasty, as the waiting period was long enough to allow for spontaneous improvement without precluding a successful outcome if drainage failed to occur. Ureterocalycostomy was rarely necessary.