Unilateral long-segment ureteral reconstruction using a bilateral Boari flap bridge: An experimental model in dogs.

Objective: The aim of this experimental study was to evaluate the feasibility of a bilateral Boari flap bridge as a novel method for unilateral long-segment ureteral reconstruction. Materials and methods: The study was conducted on eight dogs. After resection of 10 cm of right-sided distal ureter, bilateral Boari flaps were made from the anterior upper wall of the bladder and then anastomosed head to head, forming a flap bridge. The left base of the flap bridge was transected, and the free end was then anastomosed to the proximal stump of the ureter with a stent inside. A retrograde urography through a cystostomy was performed 8 weeks after the ureteral reconstruction. The animals were killed and the neoureters were examined histologically. Results: There were almost no obvious complications during the postoperative period. The urography suggested patent urine excretion and no obvious fistula or stenosis. Histopathological examinations showed an open lumen with complete urothelial lining and a healthy muscular layer with nutrient vessels. Conclusion: This study showed that ureteral reconstruction by a bilateral Boari flap bridge was anatomically possible in an animal model. Further studies are needed to confirm long-term functional efficacy.