Transplant ureteric obstruction is an uncommon but serious complication following renal transplantation. While conservative measures may restore patency, surgical revision is occasionally required. We present a unique case of transplant ureter obstruction successfully managed via total extraperitoneal Boari flap to the transplant renal pelvis.

A 58-year-old male with end-stage kidney disease due to IgA nephropathy underwent deceased donor renal transplantation. The graft had a single artery, vein, and ureter, and the transplant was uncomplicated. Ureteric anastomosis was performed via standard end-to-side neoureterocystostomy over a 6Fr stent. The patient had an uneventful recovery and was discharged on postoperative day 6. On day 33, following routine stent removal, the patient developed anuria and a marked rise in creatinine (716 µmol/L). Imaging revealed significant hydronephrosis. A percutaneous nephrostomy was placed, and creatinine normalized. Antegrade studies demonstrated a proximal ureteric kink with significant resistance to stenting. Despite intervention, the obstruction recurred upon nephrostomy clamping.

On postoperative day 71, the patient underwent ureteric revision via re-exploration of the original Rutherford Morrison incision. A significant angulation in the transplant ureter was identified below the uretero-pelvic junction. The renal pelvis was dissected and spatulated. A wide-based extraperitoneal Boari flap was created, and an end-to-end anastomosis was performed over a 7Fr 12cm stent. Bladder closure was completed in two layers. A 15Fr drain was placed, and the abdomen was closed in layers. Postoperative recovery was uneventful. A retrograde cystogram on day 11 showed no leakage. The catheter was removed on day 12, and the patient maintained adequate urine output. At follow-up, renal function remained stable (creatinine 160–200 µmol/L).

This case highlights the complexity of transplant ureteric obstruction and the feasibility of a total extraperitoneal Boari flap approach in carefully selected patients. Surgical reconstruction remains an effective option when conservative measures fail, particularly in anatomically suitable cases. Long-term graft function can be preserved with timely and meticulous reconstructive intervention.