18 Month patency of acellular bioengineered regenerative conduit as coronary artery bypass

Coronary artery bypass grafting remains the standard of care for complex coronary artery disease; however, outcomes are limited by failure or lack of suitable native vessels. Tissue-engineered vascular grafts have shown promise in peripheral applications, yet durable performance in coronary circulation remains unmet. In this study, tissue-engineered vessels are implanted with and without external support as coronary artery bypass grafts in an ovine model and anticoagulants are administered for 180 days. Unsupported vessels fail early due to kink-related thrombus, whereas external supported vessels achieve 100% patency at 180 days. Further, two animals are followed through 550 days without anticoagulant to maintain patency. The tissue engineered vessel explants demonstrate host-mediated remodeling including endothelium, no thrombus, minimal inflammatory response, and burst pressures exceeding native coronary bypass grafts. This study demonstrates preliminary, long-term patency after withdrawal of anticoagulation, with evidence of regenerative transformation into a living, functional vessel. Here the authors tested lab-grown blood vessels as heart bypass grafts in sheep, adding an external support to prevent kinking. The vessels stayed open for 18 months, even after blood thinners were stopped, while transforming into living, functional tissue.