Partial Distal Ureteral Obstruction After Pediatric Kidney Transplantation: A Diagnostic Challenge.

Ureteral complications are a significant source of morbidity after kidney transplantation. While complete ureteral obstruction is typically identified with standard imaging, partial obstruction may be more difficult to diagnose. We report the case of an eight-year-old girl who developed progressive hydronephrosis and graft dysfunction following kidney transplantation. Imaging studies, including ultrasound and retrograde pyelography, were inconclusive and failed to clearly localize the obstruction. Due to persistent graft dysfunction, surgical exploration was performed, revealing a short-segment distal ureteral stenosis approximately 1 cm from the vesical implantation site, consistent with segmental ischemia. The ureterovesical anastomosis was intact. Ureteral reimplantation resulted in the resolution of obstruction and recovery of graft function. Partial ureteral obstruction may be difficult to detect with standard imaging and should be considered in cases of unexplained graft dysfunction.