Background: Long congenital tracheal stenosis is a life-threatening condition, and the available surgical treatments do not give satisfactory long-term results.
Methods: Human embryonic tracheas were implanted in the abdominal cavities of nude mice until their differentiation was completed. These differentiated tracheas were used to patch-repair surgically induced tracheal stenosis in piglets. The human, mouse, or pig origin, of all the cells in the two successive xenotransplants in the nude mouse and the pig, was determined on tissue sections by in situ hybridization with species-specific DNA probes.
Results: The transplanted pigs thrived and reached normal adulthood, irrespective of the administration of immunosuppressive treatment. The human tracheal tissue developed in nude mice conserved human structures, with the exception of feeding capillaries, which were of mouse origin. The tracheal patch in the adult healthy pigs comprised only pig cells organized into a fibrous scar, which was covered by normal pig epithelium.
Conclusions: Results suggest that human embryonic trachea grown in nude mice can be successfully used as patch tracheoplasty for long congenital tracheal stenosis without conventional immunosuppression.