AHA Scientific Sessions 2026 Abstract · Nov 2, 2026
Evaluation of Tissue Engineered Human Vessels in Porcine and Ovine Models of Coronary Artery Bypass Grafting
By Nash K, Williams A, Benkert A et al.
Introduction: Coronary artery bypass grafting (CABG) is performed using autologous blood vessels to revascularize multivessel coronary artery disease. Saphenous vein (SV) is utilized in 80-90% of CABG procedures despite a ~25% one-year failure rate and 50% patency at ten years. In this study, we developed large-animal CABG models to investigate the use of a novel small diameter vascular conduit, an acellular coronary tissue engineered vessel (CTEV) as a potential off-the-shelf alternative to SV grafts. Methods: CTEVs were grown using human vascular cells in a custom bioreactor manufacturing platform, decellularized, and tested for biological and mechanical attributes. CTEVs were successfully implanted to the LAD, RCA, and LCx territories at clinically-relevant graft lengths (6.0-11.5 cm) in adult porcine and immunosuppressed ovine CABG models. Durability, patency, and host recellularization were assessed using doppler flowmetry, serial fluoroscopic angiography and explant immunohistochemistry. Results: Four pigs were implanted with CTEV aorta-RCA or -LAD bypasses up to 5 weeks, the maximum duration achievable due to xenogeneic host-graft limitations. Only one porcine CTEV bypass was not patent at the study endpoint and was attributed to competitive coronary flow due to improper ligation of the native artery. Duration of CTEV implantation was extended using an immunosuppressed ovine CABG model in which 3 sheep received a CTEV aorta-LCx bypass for up to 3 months. All CTEVs implanted in sheep remained patent throughout the study duration and had minimal luminal narrowing. Overall, blood flow rates through CTEV bypasses in both animal models ranged from 68-190 mL/min and there was no evidence of structural failure in any CTEV implanted. Histology demonstrated host smooth muscle cell repopulation throughout the CTEV wall and luminal endothelial cells along the entire CTEV length, including near-complete endothelialization of the lumen in proximal and distal regions in the 3-month sheep model. Conclusion: In clinically relevant large-animal models, CTEVs demonstrated early patency, structural integrity, host cellular repopulation, and progressive endothelialization, supporting further development as a potential alternative to autologous SV for CABG.