Distal ureteroureterostomy in children with duplex kidney anomalies: Safety and preservation of the recipient lower moiety.

OBJECTIVE: Distal ureteroureterostomy (UU) has become an increasingly accepted renal-preserving reconstructive option for children with duplex kidney anomalies and ectopic or obstructed upper moiety ureters. However, concerns persist that UU may compromise the healthy recipient lower moiety. The aim of this study was to evaluate the outcomes after distal UU in children with duplex kidney anomalies. METHODS: A retrospective review was performed of all children who underwent distal UU for duplex kidney anomalies at our institution between 2008 and 2025. RESULTS: Fifty-three children underwent distal UU with a median age at surgery of 15 months. Median operative time was 118 min. No intraoperative complications occurred. Early postoperative febrile urinary tract infections developed in 3/53 patients (5.7%). Forty-five children had available follow-up, with a median duration of 45 months. In patients with preoperative upper moiety hydronephrosis, significant postoperative improvement was observed (p < 0.001). No patient developed clinically relevant obstruction of the recipient lower moiety or required reoperation. Mild asymptomatic lower moiety hydronephrosis developed in only two children, both demonstrating unobstructed drainage on postoperative scintigraphy. Initial donor ureter diameter was not associated with adverse postoperative outcomes. CONCLUSION: Distal UU is a safe, effective, and definitive reconstructive option for duplex kidney anomalies. After a median follow-up of 45 months, no clinically relevant recipient lower moiety obstruction was observed and no reoperation was required.