Use of embryonic human trachea grown in nude mice to patch-repair congenital tracheal stenosis

Background, Long congenital tracheal stenosis is a life-threatening conditi on, and the available surgical treatments do not give satisfactory long-ter m results. Methods. Human embryonic tracheas were implanted in the abdominal cavities of nude mice until their differentiation was completed. These differentiate d tracheas were used to patch-repair surgically induced tracheal stenosis i n piglets. The human, mouse, or pig origin, of all the cells in the two suc cessive xenotransplants in the nude mouse and the pig, was determined on ti ssue sections by in situ hybridization with species-specific DNA probes. Results, The transplanted pigs thrived and reached normal adulthood, irresp ective of the administration of immunosuppressive treatment. The human trac heal tissue developed in nude mice conserved human structures, with the exc eption of feeding capillaries, which were of mouse origin. The tracheal pat ch in the adult healthy pigs comprised only pig cells organized into a fibr ous scar, which was covered by normal pig epithelium. Conclusions. Results suggest that human embryonic trachea grown in nude mic e can be successfully used as patch tracheoplasty for long congenital trach eal stenosis without conventional immunosuppression.