Preclinical research on the effect of thoraco-abdominal normothermic regional perfusion on pulmonary function: A comparison of 2 strategies.

Thoraco-abdominal normothermic regional perfusion (TA-NRP) is a novel technique to recover organs from donors after circulatory death by restoring regional circulation with extracorporeal support. However, its potential impact on pulmonary grafts remains unclear. This study compared pulmonary graft injuries across 2 TA-NRP protocols. In the original protocol group ("OG," n = 6), TA-NRP was initiated via central cannulation 15 minutes postcirculatory arrest, whereas in the vented protocol group ("VNT," n = 6), isolated abdominal normothermic regional perfusion and vented heart perfusion began after 15 minutes, converting to full TA-NRP after 75 minutes. Lungs were ventilated at the start of TA-NRP, extracorporeal circulation ceased after 85 minutes, and procurement occurred after an additional 80 minutes of in situ beating heart. Control lungs group (n = 4) underwent 15 minutes of warm ischemia before procurement. The partial pressure of oxygen in arterial blood to the fraction of inspiratory oxygen ratio was >400 in both lungs for VNT and OG. Pulmonary vascular resistance, computed tomography scan lung density, and histologic injury were comparable between control lungs group, OG, and VNT. In conclusion, pulmonary function remained satisfactory post-TA-NRP in both protocols. These results indicate that TA-NRP lung donation could yield grafts of acceptable quality. Further research should focus on translating these findings to the transplant setting using ex situ lung perfusion or transplant models.