Background: Lung injury (LI) due to gastric-acid aspiration is associated with poor posttransplantation outcomes. We investigated the effects of ex vivo lung perfusion (EVLP) reconditioning and surfactant administration on LI due to gastric-acid aspiration.
Methods: Thirty piglets were allocated at random to five groups: the lungs were studied 24 hr after gastric juice-induced LI of the left lower lobe (LLL), LI followed by EVLP (4 hr), or LI followed by LLL surfactant lavage immediately before EVLP; sham animals were studied 24 hr after saline infusion alone or followed by EVLP. Gross anatomy, hemodynamics, and aerodynamics were evaluated; neutrophil and bacterial counts were determined in bronchoalveolar lavage (BAL) fluid and blood. LLLs were evaluated based on a semi-quantitative histologic score, apoptotic cell death (TUNEL), and inflammatory cytokine levels.
Results: The sham and sham-EVLP groups were not significantly different. Compared with sham, LI animals had irreversible atelectasis, higher lung infection rates (P<0.0001) and BAL neutrophil percentages (P<0.0001), lower PaO2 (P=0.0006), higher IL-1 (P=0.022) and IL-8 (P=0.006), higher apoptotic cell percentages (P=0.007), and worse histologic severity scores (P<0.0001). EVLP alone did not improve these findings. Adding surfactant before EVLP returned PaO2, pulmonary vascular resistance, and apoptotic-cell percentage to sham-EVLP values but only partially improved the histologic severity score.
Conclusion: Local surfactant infusion immediately before EVLP improved the function of donor lungs injured by gastric juice aspiration. This strategy may hold promise for decreasing the shortage of donor lungs.