Feasibility of staged allogeneic larynx transplantation in dogs / 中国组织工程研究

ABSTRACT

BACKGROUND: The key to success in laryngeal transplantation is to control the infection. In practice, how to minimize the risk of infection should be considered first, so that the laryngeal allograft can survive after revascularization under the immunosuppressive state. Then the therapeutics methods should be focused on the functional recovery of respiratory, swallowing and phonation.OBJECTIVE: To explore the feasibility of staged allogeneic larynx transplant for dogs in order to decrease the infection rate.METHODS: Ten male conspecific Beagle dogs were assigned into five pairs of donor and receptor according to body mass and the size of larynx. The allogeneic larynx was embedded under the neck skin by allotransplantation. The dogs were treated with immunosuppressant daily to resist immnological rejection. The pharynx and trachea were contraposed after larynx survived to establishⅡstage laryngeal transplantation animal model.RESULTS AND CONCLUSION: InⅠstage of laryngeal transplantation, the laryngeal allograft survived well, blood supply was passable. Receptor dog 1 with vertical midline incision in the neck, receptor dogs 4 and 5 with transverse incisions in the neck grew well. No infection phenomena was found in receptor dogs 4 and 5. The lastⅡstage laryngeal transplantation was performed in the 4th week afterⅠstage laryngeal transplantation. Skin flap necrosis occurred in receptor dogs 2 and 3 with U-shape incisions. The donor larynx had different degree infection. Laryngeal allograft of receptor dog 2 died; laryngeal allograft of receptor dog 3 survived after treatment. The survival period of donor larynx in receptors was as long as 4 weeks. These findings indicate that the larynx infection is avoid or reduced by staged larynx transplantation with pre-embed laryngeal allograft after total laryngectomy. The receptor dog is tolerant; the donor larynx is easy to survive. The main histological change occurs in the epithelial mucosae which can be used as an inspect index of immunosuppressive agents. However, glandular organ secretion is a troublesome problem and immunodepressant must be continuously administrated for a long time.