New type of tracheal bioartificial organ treated with detergent: maintaining cartilage viability is necessary for successful immunosuppressant free allotransplantation.

The present investigation examined the key factors in the preparation of low-antigenic tracheal allografts by detergent treatment in dogs. In group 1 (n = 5), the grafts were treated by detergent at room temperature for 48 h and rinsed with running water until use. In group 2 (n = 4), detergent treatment was performed at 4 degrees C for 48 h, but the rinsing step was omitted. In group 3 (n = 6), the grafts were treated at 4 degrees C for 48 h, rinsed thoroughly with physiologic saline, and stored at 4 degrees C. The grafts were then used for tracheal replacement without immunosuppressant in dogs. The epithelium and mixed glands had been removed completely from the grafts in groups 1 and 2, and in five of the six grafts of group 3. In groups 1 and 2, cartilage viability appeared to have been lost and all animals died of airway stenosis within 38 days. In group 3, the chondrocytes were viable and all animals survived uneventfully. These results suggest that maintaining cartilage viability in a tracheal graft is necessary for successful immunosuppressant-free allotransplantation and, consequently, to maintain an open airway. The treatment temperature and sufficient rinsing are key factors for maintaining cartilage viability of grafts.