TRACHEAL TRANSPLANTATION FOR CARINAL RECONSTRUCTION IN DOGS

Background: Experimental carinal allotransplantation has been performe d with tracheocarinal Y-shaped allografts in dogs. In this study we tr ied canine carinal reconstruction with cylindrical allografts, Materia l and methods: Carinal reconstruction was performed with allotransplan tation of cylindrical trachea in dogs, and graft healing was evaluated by bronchoscopic observation, mucosal blood flow measurement, and his tologic examination. A section of the recipient carina containing five tracheal rings and two main stem bronchi was removed, and a donor tra chea seven rings long was inserted between the recipient trachea and t he left main stem bronchus; then side-to-end anastomosis was performed between the graft midportion and recipient right main stem bronchus ( new carina), The grafts were wrapped with pedicled omentum, Fresh graf ts were transplanted into one group of dogs (n = 8), and grafts cryopr eserved for 1 week were transplanted into another group (n = 7), Resul ts: No anastomotic leakage occurred in any dog. Excellent healing of g rafts and graft anastomoses was observed by fiberoptic bronchoscopy in six dogs (75%) in the fresh graft group and in four dogs (57%) in the cryopreserved graft group. The mucosal blood flow in the new carina d ecreased remarkably and, although it recovered, mucosal blood flow rem ained under the preoperative level on day 28 after the operation. Conc lusion: Cylindrical tracheal allotransplantation is useful for carinal reconstruction, and the method of side-to-end anastomosis between the donor trachea and recipient bronchus is a feasible and accessible pro cedure in dogs.