Cardiac Surgery Resident University of Alberta Edmonton, Alberta, Canada
Background: Ischemia-reperfusion injury and graft dysfunction following lung transplantation is a significant cause of mortality. In the realm of ex vivo lung perfusion (EVLP), previous evidence has suggested that platelet activation and distal arterial thrombosis may play a role in both conditions.
METHODS AND RESULTS:
Methods: Lungs were procured from juvenile Yorkshire pigs for EVLP. The standard EVLP protocol included perfusate with common hospital ingredient perfusate (CHIP) and autologous packed red blood cells and lung protective ventilation over 12 hours. Every three hours, an evaluation is performed by increasing cardiac output from 30%->50% and applying mixed sweep gas through the de-oxygenator for 5 minutes. Standard lung performance characteristics are regularly assessed including PF ratio, pulmonary vascular resistance (PVR), dynamic compliance, and minute ventilation. The experimental group received dual antiplatelet therapy (DAPT) with 325mg of aspirin and 180mg of ticagrelor administered to the pig 30 minutes prior to pneumonectomy and the same dose added to the perfusate. Unpaired two-tailed T tests were used to compare differences in physiologic parameters. All statistical analyses were performed via GraphPad Prism (GraphPad Software, La Jolla, CA, USA).
Results: Dynamic compliance and minute ventilation were significantly higher in the group that received antiplatelets compared to the control group (p < 0.001). Other measures of lung function including PVR, pulmonary artery pressure, PF ratio, and lactate formation, were similar between groups (p=0.15-0.96).
Conclusion: The administration of DAPT during EVLP results in improved compliance and ventilation. Previous literature has identified platelet activation and distal arterial thrombosis as a potential contributor to graft dysfunction following lung transplantation. Clinical studies on EVLP prior to human transplantation are required to determine whether these findings will translate to improvement in outcomes following lung transplantation. Similar investigations should also be pursued for other solid organ transplantation, such as heart transplantation, to determine whether similar treatments impact function.
