Negative Pressure Ventilation Ex-Situ Lung Perfusion Preserves Porcine and Human Lungs for 36-Hours.

Introduction: Preclinically, 24-hour continuous Ex-Situ Lung Perfusion (ESLP) is the longest duration achieved in large animal models and rejected human lungs. Here, we present our 36-hour Negative Pressure Ventilation (NPV)-ESLP protocol applied to porcine and rejected human lungs.

Methods: Five sets of donor domestic pig lungs (45-55 kg) underwent 36-hour NPV-ESLP. Two sets of clinically rejected human lungs were preserved on 36-hour NPV-ESLP. Graft function was assessed via physiologic parameters, edema formation, and cytokine profiles.

Results: Porcine and human lung function was stable with mean partial pressure of oxygen divided by the fraction of inspired oxygen (PaO2/FiO2; PF) ratios throughout preservation of 473±11.79 and 554.7±13.26, respectively (mean±standard error of the mean). In porcine lungs, mean compliance (Cdyn) during ESLP was 33.96±2.18, pulmonary artery pressure (PAP) 13.03±0.53, and pulmonary vascular resistance (PVR) 481.20 ±21.86. In human lungs, mean Cdyn was 82.68±3.54, PAP 6.00±0.33, and PVR 184.00±9.71. Average percentage weight-gain was 34.47±13.22 in porcine lungs and 116.3±6.65 in rejected human lungs.

Conclusion: NPV-ESLP can preserve porcine lungs and human lungs for 36-hours with acceptable physiologic function. Greater weight-gain in the human lungs is likely due to prolonged ischemic time prior to ESLP and use of an acellular perfusate. Continuous 36-hour NPV-ESLP could support therapies for endothelial protection and mitigate fluid accumulation.