In vivo Implantation of 3D Printed Customized Branched Tissue Engineered Vascular Graft in Porcine Model

Abstract Objectives The customized vascular graft offers potential to simplify the surgical procedure, optimize physiological function, and reduce morbidity and mortality. This experiment evaluated the feasibility of a flow dynamic optimized branched tissue engineered vascular graft (TEVG) customized based on medical imaging and manufactured by 3D printing for a porcine model. Methods We acquired magnetic resonance angiography (MRA) and 4D flow data for the native anatomy of the pigs (N=2) to design a custom-made, branched vascular graft of the pulmonary bifurcation. An optimal shape of the branched vascular graft was designed using computer aided design (CAD) system informed by computational flow dynamics (CFD) analysis. We manufactured and implanted the graft for pulmonary artery (PA) reconstruction in the porcine model. The graft was explanted four weeks after implantation for further evaluation. Results The custom-made branched PA graft had a wall shear stress and pressure drop (PD) from the main PA to the branch PA comparable to the native vessel. At the end point, , the MRI revealed comparable left/right pulmonary blood flow balance. PD from main PA to branch between before and after the graft implantation was unchanged. Immunohistochemistry showed evidence of endothelization and smooth muscle layer formation without calcification of the graft. Conclusion Our animal model demonstrates feasibility of design and implantation of image-guided, 3D printed, customized grafts. These grafts can be designed to optimize both anatomically fit and hemodynamic properties. This study demonstrates the tremendous potential structural and physiological advantages of a customized tissue engineered vascular graft in cardiac surgery.