Three-Dimensional-Printed Bioengineered Tracheal Grafts: Preclinical Results and Potential for Human Use

Background: We aimed to develop a process using three-dimensional (3D) printing to create bioengineered tracheal grafts (BETGs) for reconstruction of anterior tracheal defects in a large-animal model (porcine) that would have translational relevance for potential human use.

Methods: Preoperative computed tomographic scans were used to create virtual 3D models of the animal airways. Anatomically scaled tracheal grafts were subsequently developed using 3D-printed polycaprolactone and extracellular matrix. A 4-cm anterior tracheal defect (about 50% of the length of the subject trachea) was surgically created in 4-week-old female Yorkshire pigs and reconstructed using the customized grafts. Gross and microscopic analyses of the grafts were performed.

Results: The BETGs were implanted in 7 animals. There was adequate graft-native trachea size match at the operation. The trachea was successfully reconstructed in all cases. Gross examination at autopsy showed a structurally intact, well-incorporated graft. Histologic evaluation showed respiratory mucosal coverage and vascularity of the graft. Five of 7 animals outlived the 3-month study period. The animals had approximately 100% growth during the study period.

Conclusions: We report of a 3D-printed BETG to repair long-segment anterior tracheal defects in a large-animal model. Although the study duration is short, this work presents an efficient strategy for tracheal graft bioengineering with potential translational relevance for human use.