Early Pyeloplasty for Recovery of Parenchymal Thickness in Children with Unilateral Ureteropelvic Junction Obstruction

Abstract

Objective: We compared renal function before and after pyeloplasty in children with unilateral ureteropelvic junction obstruction (UPJO) according to the children's age. Methods: We reviewed the medical records of 36 children with UPJO who had undergone pyeloplasty and showed improved urine drainage on postoperative diuretic renal scan. The children were divided into two groups according to their age at the time of surgery: group I, ≤1 year of age (n = 15), and group II, >1 year of age (n = 21). Parenchymal thickness (PT) and pelvic anteroposterior diameter measured by ultrasonography and renal function measured by ^99mTc-MAG3 renal scan were compared before and after surgery. Results: Group I patients, who underwent pyeloplasty within 1 year of birth, showed significant recovery of the PT ratio at follow-up evaluation (from 0.50 ± 0.13 preoperatively to 0.83 ± 0.23 postoperatively; p = 0.029) compared with that in group II (from 0.74 ± 0.23 preoperatively to 0.75 ± 0.18 postoperatively; NS). The mean differences in the PT ratio before and after surgery were 0.29 ± 0.25 and 0.02 ± 0.18 in groups I and II, respectively. Conclusion: This result suggests that early surgery improves subsequent parenchymal growth of the involved renal unit.