[Results of heterologous tracheal transplants in animal experiments (author's transl)].

In the present study, 7 x 15 mm Cialit-preserved human tracheal segments were grafted to the tracheas of five 3-month old piglets. 72-120 days later, the animals were sacrificed and the grafts with proximal and distal control areas were removed. Tissues were then examined macroscopically and by light and scanning electron microscopy. We found that: (1) all grafts had taken well; (2) no animal suffered from clinical signs of respiratory obstruction or inflammation; (3) although luminal diameters of the tracheas increased from 8 mm to 22 mm, the size of the grafts remained unchanged but the resulting tracheal stenosis did not cause respiratory obstruction; (4) the graftet areas showed re-epithelialization. The nature of the re-epithelialization as well as the fate of the submucosa and tracheal cartilage will be reported in a subsequent publication.