Effect of Thoraco-Abdominal Normothermic Regional Perfusion on Pulmonary Grafts in a Porcine Model of Warm Ischemic Injury

Abstract

<h3>Purpose</h3> Thoraco-abdominal normothermic regional perfusion (TA-NRP) is a novel technique to recover organs from donors after circulatory death (DCD). By restarting regional circulation with an extracorporeal support system, the effects of warm ischemia can be mitigated and suitability for transplantation of the organs can be assessed. Little is known of the potential injury of TA-NRP on the pulmonary graft. We developed a porcine model of DCD TA-NRP and compared the potential injury on the pulmonary graft with lungs subjected to a short warm ischemic interval without TA-NRP. <h3>Methods</h3> 15 minutes after circulatory arrest (n=7), TA-NRP was initiated via central cannulation with clamped supra-aortic vessels. Lungs were ventilated at the start of TA-NRP (tidal volume 8 mL/kg, FiO2 at 40%, PEEP of 5cmH2O, respiratory rate of 15). After 60 minutes, TA-NRP was weaned and lungs were explanted. Control lungs (n=4, CTRL) were subjected to 15 minutes warm ischemia and explanted. We performed histological analysis and ex-vivo CT imaging. <h3>Results</h3> CT density of the TA-NRP lungs were comparable between CTRL and TA-NRP, indicating similar levels of water accumulation. Data are expressed in figure 1. In addition, histological assessment (scoring for interstitial and alveolar edema, hemorrhage, interstitial cell infiltration, intra-alveolar neutrophil infiltration and hyaline membrane) of CTRL versus TA-NRP did not differ. <h3>Conclusion</h3> In our porcine DCD model, TA-NRP did not affect lung quality compared to lungs only subjected to 15 minutes of warm ischemia. As it is known that lungs are more resistant to warm ischemia than other organs and that the outcome of DCD lung donation without TA-NRP is comparable to DBD lung donation, our findings open perspectives to further explore the potential of TA-NRP in lung transplantation.