Introduction: Lung transplantation is the treatment for end-stage lung disease patients. The most commonly used source are donation after brain death donors, however due to shortage, donation after circulatory death (DCD) donors are also used. In this group an agonal phase and a period of warm ischemia are inevitable. For DCD donors, a new technique called normothermic regional perfusion (NRP) presented with increased organ utilization rates.(1) Using an extracorporeal membrane oxygenation machine, abdominal circulation in-situ is restored post-mortem. This restores cellular energy substrates and enables one to assess organ function pre-procurement. First efforts in extending this technique to the thorax were highly beneficial for hearts, remarkably, almost no lungs were transplanted using an oxygen strategy of 21%.(2) Thoraco-abdominal NRP (TA-NRP) might be detrimental to the lungs, because the right ventricle is not loaded to create perfusion to the lungs. Furthermore, washout of inflammatory substances from other areas, into the lungs may cause significant harm. Here we present our first results on lungs comparing two oxygen strategies in TA-NRP Materials and Methods: Pigs were randomized into group 100% oxygen (n=6) and group 21% oxygen (n=6), anesthetized and centrally cannulated to a heart-lung machine. Ventilation was switched off to induce circulatory arrest (pulse <20 mmHg). After a no-touch period of 15 minutes, circulation and ventilation were restarted, sinus rhythm was restored, and the heart was gradually loaded to perfuse the lungs. After 35 minutes of reperfusion, pigs were weaned off of life support and oxygen went from 21% to 40% or 100% to 60%. A total reperfusion time of 3 hours post-circulatory arrest was upheld. Lung biopsies were taken at baseline, 10 minutes after no touch (No Touch 10), and 60 and 180 minutes after reperfusion (Post-R-60 and -180). Biopsies were dried for 24 hours at 60°C to determine oedema. Arterial and venous blood gases were taken throughout the procedure. Results: Dry weight as a percentage of wet weight did not differ significantly between 100% and 21% oxygen therapy group, respectively at baseline 87,5% and 88,4% (p = 0.74), NT10 84,1% and 84,5% (p = 0.93), R60 90,2% and 87,8% (p = 0,23), and R180 80,7% and 89,1% (p = 0,25).Arterial and venous blood gas saturation differed significantly starting at time point R3 until time point R25 (p <0.05).Arterial and venous pO2 (kPa) were also significantly higher in the 100% oxygen group, starting from R3 to R45.Conclusion: In our set-up, all lungs were able to reach 100% saturation and pO2 >14kPa, even after 15 minutes of circulatory arrest and TA-NRP treatment. No significant changes were seen in the dry weight/wet weight percentages. There seems to be no real harm done to the lungs, by either TA-NRP approach. However, the better venous pO2 in the 100% group indicates a better whole-body oxygenation.