Case Report: Vascular bypass for accessory renal artery-induced ureteropelvic junction obstruction after kidney transplantation

Extrinsic vascular compression is an uncommon cause of ureteropelvic junction obstruction after kidney transplantation. A 24-year-old woman developed recurrent hydronephrosis following living donor kidney transplantation. Ureteral stenting improved drainage, but hydronephrosis worsened after stent removal despite relatively stable serum creatinine. Computed tomography demonstrated a lower-pole accessory renal artery crossing the ureteropelvic junction. Exploration confirmed compression, and arterial division immediately decompressed the renal pelvis and restored urine flow into the distal ureter. Dense adhesions prevented relocation of the original arterial anastomosis. Therefore, a reversed autologous great saphenous vein bypass from the external iliac artery to the accessory artery was constructed, preserving lower-pole perfusion without ureteral reconstruction or further stenting. At nine months, hydronephrosis had been resolved and the bypass remained patent. This case shows the feasibility of vascular rerouting for selected cases of transplant ureteropelvic junction obstruction caused by an accessory artery, although longer follow-up is needed to assess durability.