Metaplastic transformation of an aortic autograft into a tracheal tissue. Surgical implications

Tracheal reconstruction after extensive resection remains an unsolved surgi cal problem. Numerous attempts have been made using tracheal grafts or pros thetic conduits with disappointing results. In this study, we propose a new alternative using an aortic autograft as tracheal substitute. In a first s eries of experiments, a half circumference of two rings was replaced with a n autologous carotid artery patch. In a second series, a complete segment o f trachea was replaced with an autologous aortic graft supported by an endo luminal tracheal stent. No dehiscence or stenosis was observed. Microscopic examinations at 3 and 6 months showed the replacement of the aortic tissue by tracheal tissue comprising neoformation of cartilage and mucociliary or non-keratinizing metaplastic polystratified squamous epithelium. Although these results need to be confirmed by a larger series of experiments, they showed that a vascular tissue placed in a different environment with a diff erent function can be submitted to a metaplastic transformation which tends to restore a normal structure adapted to its new function. These remarkabl e findings offer new perspectives in tracheal reconstruction in human. (C) 2000 Academie des sciences/Editions scientifiques et medicales Elsevier SAS .