Trachea Replacement with Cryopreserved Tracheal Allograft: Experiment in Dogs

Kim, Do Hyung; Paik, Hyo Chae; Cho, Sang Ho; Cho, Kyu Seok; Lee, Doo Yun

Abstract

PURPOSE: Tracheal transplantation is necessary in patients with extensive tracheal stenosis caused by trauma, congenital disease, benign or malignant tumor. Results with the cryopreserved vascular homograft have prompted us to evaluate cryopreserved trachea. When trachea is cryopreserved, it maintains viability of the cartilage and allogenicity decreased because epithelium of trachea whitch has major allogenicity (MHC class II Antigen) is exfoliated after some periods of cryopreservation. We assessed the proper duration of cryopreservation and probability of trachea allotransplantation.
METHODS
The trachea were harvested from Mongrel dogs and frozen to 80degrees C for different length preservation (group 1: 1~10 week, group 2: 1 month, 2 months, 3 months, 6 months, 2 months). Ggoup 1 was thawed and tested epithelial viability, Group 2 was perfomed trachea transplantation with cryopreserved trachea allograft, after one months We checked gross appearance, viability of cartilage and grade of monocyte infiltration (rejection).
RESULTS
In group 1, Exfoliation of epithelium was begun after four weeks cryopreservation, in group 2, when allograft was extracted, trachea of 4 dogs was stenosed, and six months preserved trachea was not seen due to total necrosis. Cartilage viability of 4 case of transplantation, three of 4 case were mild infiltration of monocyte.
CONCLUSION
We conclude that more than 1 month cryopreservation for prevention of rejection and additional procedure (omentopexy) for graft vascular supply are needed for trachea transplatation. Although cryopreservation was performed, all case of transplantation happened some degree graft rejection. if trachea transplantation will be applied, immune suppress will be needed.