Preservation of bronchial artery circulation on ex-vivo lung perfusion

Lungs receive blood supply from the pulmonary and bronchial arteries. After transplantation, lungs uniquely suffer from ischemia and injury to the airways, in part due to the surgical sacrifice of the bronchial artery circulation during procurement and implantation. Ex-vivo lung perfusion (EVLP) offers a platform to rehabilitate and assess donor lungs; however, it traditionally excludes bronchial circulation. We hypothesized that bronchial artery perfusion during EVLP may enhance airway preservation. A dual-circulation EVLP platform was developed using swine donor lungs with preserved bronchial arteries. Blood was separately routed to the pulmonary artery and to the bronchial arteries. Laser speckle contrast imaging (LASCA) was performed pre- and post-initiation of bronchial perfusion, and perfusion units were compared within lungs. Endpoint lung function and tissue integrity were assessed via histology and TUNEL staining after 6 h of perfusion. Six porcine lungs were successfully mounted on the dual-circulation EVLP system. Bronchial perfusion significantly increased airway perfusion (p = 0.03), with trends toward improved parenchymal perfusion as well. Histology demonstrated preserved architecture and less necrosis in the airways of dually perfused lungs. TUNEL staining demonstrated significantly reduced bronchial epithelial apoptosis in dual-perfused lungs compared to PA-only perfusion (p < 0.001). This study demonstrates the feasibility of dual-circulation EVLP in a large animal model and reveals early protective effects of bronchial artery perfusion on airway tissues. These findings suggest that incorporating bronchial perfusion into EVLP platforms may mitigate early ischemic airway injury, a key contributor to post-transplant complications and chronic lung allograft dysfunction. Further investigation is warranted to assess functional outcomes and long-term benefits, and to evaluate integration with bronchial artery revascularization strategies.