Lung Injuries Induced by Gastric Acid Aspiration Are Attenuated by Exogenous Surfactant during Ex Vivo Reconditioning in Pigs

Purpose Gastric acid aspiration is a common reason for rejecting lungs for transplantation as it is associated with increased risks of graft dysfunction. We investigated Ex vivo lung perfusion (EVLP) reconditioning on lung injuries due to gastric acid aspiration and effects of surfactant administration. Methods and Materials 30 piglets were allocated to 5 groups. Aspiration lung injury (LI) was induced by infusing 1 ml/kg of autologous gastric juice into the left lower lobe (LLL). 24 hours later, the lungs were studied (LI group) or reconditioned using EVLP for 4 hours without additional treatment (LI-EVLP group) or after surfactant lavage (curosurf 100 mg/kg) in the LLL (Surf-EVLP group). Sham animals were studied 24 h after saline infusion and Sham-EVLP animals 24 h after saline infusion followed by 4 h of EVLP. Gross anatomy, hemodynamics, and aerodynamics were evaluated; neutrophil and bacterial counts in bronchoalveolar lavage (BAL) fluid and blood were determined. LLLs were evaluated by tissue wet/dry ratio; histology (semi-quantitative severity score); apoptotic cell using TUNEL; and IL-1, IL-6, IL-8, IL-10, and TNFa protein levels. Results There were no significant differences between the Sham and Sham-EVLP groups. Compared to Sham, LI animals had irreversible atelectasis, a higher lung infection rate (P 2 (P=0.0006), higher IL1 (P=0.022) and IL8 (P=0.006) levels and apoptotic cell percentage (P=0.007), and worse histology severity score (P Conclusions Although 4 hours EVLP worsened LI due to gastric acid aspiration, when preceded by local infusion of surfactant it allowed complete PaO2 and partial histology recovery.