Porcine Model of Donation after Cardiac Death (DCD) and Evaluation of Pulmonary Function Using Ex-vivo Lung Perfusion (EVLP)

Objective The limiting factor when using lungs from donors after cardiac death (DCD) is the duration of warm ischemic time, which is linked to reperfusion edema. Within the context of lung shortages, and in order to avoid transplanting damaged lungs, ex-vivo lung perfusion (EVLP) has emerged as an innovative tool to preserve and recondition donor lungs. Using the EVLP technique in a porcine model, the purpose of this study is to determine the duration of warm ischemia that donor lungs can tolerate before they are viewed as non-viable for transplant. Methods This study is comprised of 5 groups (n=2-6/group). Four groups endured different warm ischemic times, whilst the fifth group underwent cold ischemia. The lungs were subsequently perfused outside the body using the EVLP platform for four hours. Results 120 minutes of warm ischemia is more damaging for lungs than 120 minutes of cold ischemia, even after being reconditioned on the EVLP platform (50,4 ± 8,9% vs. 3,3 ± 3,4% of weight gain). This would signify that two hours of warm ischemia is incompatible with transplantation. However, 90 minutes and 60 minutes of warm ischemia seems to have less of an effect on pulmonary functions. Indeed, the lungs of both these groups had less than 14% of weight gain and maintained oxygenating capacities (PaO2/FiO2 of 514 ± 12 and 586 ± 0 mmHg respectively.) Conclusion Lungs having been submitted to less than 90 minutes of warm ischemia and evaluated with EVLP may be suitable candidates for transplantation.