Some physicians believe that squamous metaplasia may be a forerunner of epidermoid bronchogenic carcinoma. An experimental method for producing squamous metaplasia of respiratory epithelium might have some value in investigating the etiology of bronchogenic carcinoma.
Review of Literature
In 1956 we reported the surgical reversal of the cervical trachea in the dog.1 That work was done primarily for the study of the properties of regeneration of respiratory epithelium. It demonstrated the following facts.The devascularized free graft of autologous trachea lost its ciliated columnar epithelium. The surviving portion of the epithelial lining of the tracheal graft was represented by islands of basal cells. The basal cells gave rise to normal-appearing respiratory epithelium as soon as the graft became revascularized, usually within three weeks. The regenerated cilia beat in the same direction as their predecessors, causing the mucous stream in the reversed graft to flow caudad.Two by-products of