[Experimental tracheal reconstruction by allotransplantation]

Reconstruction using allotransplantation was successfully performed for large defects of the trachea. The defects of ten tracheal rings were surgically created in 28 mongrel dogs and they were repaired with allografts of 5 rings, using over-and-over continuous suture technique with 4-0 Prolene. After the completion of anastomosis, omental pedicle was used to wrap the allograft including both the ends of the graft. Immunosuppressant FR900506 (FK506) was daily administered with a dose of 0.1 mg/kg body weight intramuscularly. When the dogs were sacrificed or succumbed, all the grafts were excised and were examined microscopically and scanning electron microscopically. In some of them, the revascularization from the omental pedicle was examined by infusion of Indian ink from the feeding artery. Eleven dogs survived for more than 30 days and 3 of them did over 120 days. The longest survival is 202 days and the dog is now alive. Twenty out of the 28 allografts were proved to be viable with normal tracheal structure and also free of granulation or stricture. One dog died of perforation of the graft due to rejection. Another dog succumbed from other disease, but the graft was necrotized without the sign of rejection. The viability of the grafts of the remaining 6 dogs were not determined, because the survival time were not long enough, although the grafts were intact macroscopically and microscopically. Three or four weeks after transplantation, the surface of the graft was covered with ciliated epithelium and the tracheal architects were almost normalized. It was proved that revascularization of the tracheal graft from the omental pedicle was established within 7 days following the operation.(ABSTRACT TRUNCATED AT 250 WORDS)