Transplantation of the decellularized tracheal allograft in animal model (rabbit)

It has been difficult to perform tracheal allotransplantation without immunosuppression. To determine whether decellularized trachea can be used in tracheal replacement, we evaluated the viability of decellularized tracheal allografts in a rabbit model of immunosuppressant-free transplantation.

Half allograft (Group 1, n = 7) was harvested from adult New Zealand white rabbits, subjected to a detergent-enzymatic method (containing sodium deoxycholate/DNase lavations) of decellularization for as many cycles as needed, and the other half was stored in phosphate-buffered saline at 4°C as a control (Group 2, n = 7). Bioengineered and control tracheas were then implanted in 14 age-matched rabbits.

In Group 1 (decellularized), all rabbits survived, whereas in Group 2(control), all rabbits died of airway obstruction between 20 days and 45 days after operation. Histologically, the decellularized allografts displayed complete regeneration of epithelium and cartilage, but the fresh allografts showed inflammatory changes, no epithelium, and no cartilage.

Complete regeneration of epithelium and cartilage tracheal rings occurred after the implantation of decellularized tracheal allografts without immunosuppression. We demonstrate that the decellularized process reduces the allogeneic response to the trachea. Therefore, we believe that the decellularized tracheal allograft is an excellent choice for tracheal replacement. To our knowledge, this is the first study to observe the long-term (1 year) prognosis of this transplanted trachea.