Tracheal Replacement by Allogenic Aorta in the Pig

Tracheal Replacement by Allogenic Aorta in the PigPathologic processes involving the trachea and the carina pose major difficulties for chest physicians. Although techniques have been developed enabling primary resection and reconstruction, extensive tracheal resections remains challenging and many nonresectable tumors are still managed palliatively by stenting and radiation.
Fifteen years ago, at a time of major advances in organ transplantation, Hermes Grillo2 said “we have to remain very imaginative and open-minded about this thus far unresolved dilemma – replacement of the tracheal conduit.” Twelve years later, the same author, when critically reviewing the numerous pathways used in the search for an ideal tracheal substitute, skeptically pointed out that no technique had produced results reliable enough to permit tracheobronchial replacement in a clinical setting.
However, work by Martinod et al and Seguin et al in the Laboratory of Heart Transplantation and Prostheses in Paris seems promising. This group showed that in a sheep model, fresh aortic grafts could act as a scaffold, promoting regeneration of a “neotrachea.” This neotrachea is comprised of a normal tracheal epithelium with basal, secretory, and ciliated cells; a posterior membrane; and, above all, cartilaginous rings strong enough to enable withdrawal of the indwelling silicone stent placed to prevent airway collapse. This newly described biological process opens up a therapeutic horizon for patients with extensive tracheal lesions; however, it remains subject to considerable caution and some skepticism.
Prior to considering tracheal replacement in patients, it is essential to verify whether this technique can be reproduced in another species. The experimentation reported herein was carried out to address this question. Tracheal replacement with a fresh aortic allograft (AA) was performed in 21 male, nonsyngeneic, adult minipigs (Pannier SA; Wylder, France) weighing 25 to 30 kg. Tracheobronchial size in such pigs is equivalent to that of a human adult, and thus permits bronchoscopy using the same instruments as used in humans. Aortic grafts were removed from healthy, female, large white-landrace piglets. The animals received care in accordance with French regulations and institutional ethical committee guidelines for animal research, and were housed in our institution at the University Hospital Department of Experimental Research.

This entry was posted in Allogenic Aorta and tagged airway, lung cancer, transplants.