Successful tracheal autotransplantation with a vascularized omental flap

A major problem in tracheal transplantation is the restoration of an adequate vascular supply to the transplanted trachea. In 12 piglets, a segment (6 rings) of thoracic trachea was removed and the excised segment was then sutured back in place. In 9 animals (group A), a vascularized omental flap was wrapped around the autotransplanted trachea. In the other 3 pigs (group B), the omentum was not used. Eight of 9 group A pigs were killed, 1 or 2 months later, having had no signs of airway obstruction; the 9th pig was killed after 14 days because of airway obstruction. The 3 pigs in group B were killed after 11 to 13 days because of progressive respiratory obstruction. In the 8 asymptomatic pigs in group A, the omental flap was viable and tracheal growth was normal with no differences in diameter between normal and autotransplanted trachea. Histologically intact cartilage was lined with respiratory epithelium. In the one group A pig who was killed early, the omental flap was necrotic. In this pig and in the 3 group B animals, extensive tracheal necrosis and nonviable cartilage were observed. These findings indicate that in the pig, a 6-ring segment of trachea can be transplanted with vascularization provided by an omental flap.