Lung transplantation remains the only curative treatment for end-stage pulmonary disease. Lung ischemia-reperfusion injury (IRI) is a major contributor to primary allograft dysfunction and donor organ nonutilization. The alveolar macrophage is a key inflammatory mediator in IRI. Ex vivo lung perfusion (EVLP) has been investigated to rehabilitate lungs before transplant but has failed to provide significant improvements after IRI. We hypothesized that liquid ventilation (LV) could be utilized for ex vivo lung reconditioning in a rat IRI model. We compared EVLP with LV in an isolated ex vivo rat lung with an aqueous ventilant using quantitative physiological and immunological parameters. We observed improved physiological parameters and mechanical clearance of alveolar macrophages and cytokines halting the propagation of the inflammatory response in IRI. While the wide applicability to large animal or human transplantation have yet to be explored, these findings represent a method for lung reconditioning in the setting of significant IRI that could widen the lung organ donation pool and limit morbidity and mortality associated with ischemia-induced primary graft dysfunction.
Keywords: EVLP; ischemia–reperfusion injury; liquid ventilation; lung transplantation; macrophage.