A rabbit model of free bladder mucosal grafting in a damaged urethral bed

Proximal and distal penile-urethral stomas were created in the rabbit and 1 to 3 months later a free bladder mucosal graft was placed in the damaged urethral bed. The graft adhered to a rapidly proliferating submucosa with active regeneration by post-transplantation day 5. All grafts were adherent and viable by days 10 to 14, during which time sham operated animals that had been stented only showed a degree of epithelial regeneration that was of variable quality and without submucosal proliferation. The graft may stimulate the subepithelial layer, and the most viable bladder mucosa may be associated with the most actively proliferating subepithelial layer, which is also the area of greatest neovascularity. Further studies may explain the apparent paradox of how a free bladder mucosal graft survives in a poorly vascularized, scarred urethral bed.