Long-term outcomes of dismembered pyeloplasty for midline-crossing giant hydronephrosis caused by ureteropelvic junction obstruction in children.

OBJECTIVES: To assess the long-term surgical outcomes of dismembered pyeloplasty for congenital midline-crossing giant hydronephrosis (GH) caused by ureteropelvic junction obstruction (UPJO).

METHODS: From June 1986 to September 2005, 167 unilateral UPJO pediatric patients who underwent dismembered pyeloplasty performed by a single surgeon were retrospectively analyzed. The patients were followed up for more than 5 years. Differential renal function (DRF) assessed by DTPA renal scan more than 3 years postoperatively was compared between GH and non-GH children. Improvement in renal parenchymal thickness (RPT) on ultrasonography at 5 years postsurgery was also compared. In GH children, surgical outcomes were compared based on the age at operation and whether preoperative nephrostomy was performed.

RESULTS: DRF measured more than 3 years postoperatively was 33 ± 14% versus 48 ± 12% (P < .05), and the improvement of RPT was 4 ± 2 mm (181%) versus 5 ± 4 mm (168%) in GH (n = 25) and non-GH (n = 142) children, respectively (P = .305). GH patients who underwent pyeloplasty before 12 months of age (n = 13) experienced more improvement in RPT (192% vs 102%) compared with GH patients who underwent surgery after 12 months of age (n = 12) (P < .05). The surgical outcomes for RPT improvement or long-term DRF were not different based on whether preoperative nephrostomy was performed. No children developed hypertension or elevated serum creatinine.

CONCLUSIONS: Long-term surgical outcomes after dismembered pyeloplasty for GH were satisfactory. In children with GH caused by UPJO, early relief of obstruction allows comparable nephron sparing.