Combined inflation and cooling method improves lung function in uncontrolled donation after circulatory death

Currently, the two methods used to preserve lungs from uncontrolled donation after circulatory death-topical cooling and inflation-result in the suboptimal utilization of lungs. This study aimed to introduce an approach that combines cooling and inflation to investigate whether it improves lung conditions in a swine model, even if the lungs had been damaged with long-term warm ischemia, such as in out-of-hospital cardiac arrest. Donor lungs subjected to 1.5 h of warm ischemia were divided into three groups: the Cooling group, Inflation group, and Inflation with Cooling group (n=5 per group). Lung preservation was performed for 3 h, followed by left lung transplantation. Functional assessments were conducted over 4 h after transplantation. The Inflation with Cooling group achieved significantly better oxygenation after 1 h of reperfusion. Dynamic lung compliance was higher in the Inflation with Cooling group than in the Cooling and Inflation groups. Additionally, the wet/dry weight ratio after lung transplantation in the Inflation with Cooling group was lower than that in the other two groups. The Inflation with Cooling group exhibited less severe post-transplantation pathological lung injury. The combination of inflation and cooling maintained superior pulmonary function compared with existing methods. This method has the potential to prevent the deterioration of lungs from uncontrolled donation after circulatory death, resulting in increased lung utilization.