Experimental tracheal transplantation using a cryopreserved aortic allograft

Background: The tracheal reconstruction after wide resections remains a cri tical surgical problem. Our aim was to replace trachea with a tissue easy t o vascularize, which allows a simple reconstruction and does not require an immunosuppressive regimen. Materials and Methods: A segment of cryopreserv ed aorta was used in order to verify its adequacy as tracheal substitute. I n phase 1, the thoracic aorta of 10 rabbits was excised, obtaining 20 segme nts that were cryopreserved. Ten segments were implanted in the omentum of 10 rabbits that were sacrificed on postoperative days 7, 14 and 21, and the grafts were examined histologically. In phase 2, a segment of cryopreserve d aorta arranged with a silicone prosthesis was transplanted in 10 rabbits and wrapped with omentum. The animals were sacrificed on postoperative days 7, 14 and 21. Results: In phase 1,the neovascularization of the grafts was present after 7 days, and after 14 days the fibroblasts invaded the lumen of the aorta. In phase 2, 8 rabbits survived and the histologic examination after 7, 14 and 21 days showed neovascularization, the absence of rejectio n and the proliferation of fibroblasts inside the lumen of the aorta; this growth has been restrained by an endoluminal prosthesis. Conclusions: Our s tudy demonstrated that replacing the trachea with cryopreserved aorta is te chnically feasible and does not evoke immunologic reactions. It requires, h owever, a silicone tube inside the allograft to limit the colonization of f ibroblasts.