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

Abstract

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. 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% ofthe 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. The BETGs were implanted in 7 animals. There was adequate graft-native trachea size match at the operation. The trachea was successfully reconstructed inall 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. 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.