[Revitalization of bovine xenograft used for repair of experimental tracheal defects (author's transl)].

In 12 mongrel dogs tracheal defects of different size were covered by bovine xenografts. The grafts were subjected to electronmicroscopic examination 2 to 19 months after implantation. Following the ingrowht of fibroblasts and capillaries a basal membrane is formed on the side of the previous graft lumen. After 4 to 5 months this membrane is covered from the tracheal margins by microvillous cells. After 8 months ciliated epithelia and goblet cells are developed by cell metaplasia. Although the graft becomes revitalized and integrated into the tracheal wall, the layer of ciliated epithelia is interrupted by less differentiated cells. The possible causes for this phenomenon are discussed. Thus bovine xenograft used for the repair of tracheal defects has the following advantages: total revitalization, no shrinkage, less prone to infection and formations of ciliated epithelia.