The purpose of this review is to explore the lessons learned from experimental and human tracheal transplantation to determine if this information may be applied to lung transplantation. Experimental work in animal models and the recent human tracheal transplantation suggests that a robust tracheal vascular supply prevents anastomotic complications. Further, this work demonstrates that tracheal allografts undergo a progressive chimerism as recipient epithelium repopulates the allograft. In contrast to most vascularized composite allografts such as hand and face transplantation that experience high rates of rejection, the tracheal allograft did not demonstrate rejection. This may suggest that tissue chimerism plays a role in evading immune-mediated allograft rejection. While anastomotic complications and chronic allograft rejection are the most common complications related to lung transplantation, the findings associated with tracheal transplantation may have implications for both reducing complications associated with lung transplantation.
Read full abstract