Cold static preservation at 4 °C is the clinical standard for donor lung storage but is limited to 6–8 h of cold ischemia. Static storage at 10 °C has been shown to extend ischemia times and improve lung health. Given that lungs can maintain aerobic metabolism ex vivo, we hypothesized that adding ventilation at 10 °C would further prolong preservation by stimulating aerobic metabolism. Lungs were procured from C57Bl/6 mice and then stored for 24 h with ventilation at 10 °C ( n = 4), statically at 10 °C ( n = 4), or statically at 4 °C ( n = 4). Respiratory mechanics were evaluated using a FlexiVent system. Cellular viability was assessed via flow cytometry. Complement shedding was evaluated by enzyme-linked immunosorbent assay. Histologic evidence of lung injury was assessed by H&E staining. Donor lungs stored with ventilation at 10 °C exhibited significantly reduced histologic injury scores compared to static storage at 4 °C ( p = 0.0062). Ventilation also decreased complement C3 shedding ( p < 0.01), apoptosis ( p < 0.05), cytochrome c release ( p = 0.0014), and ROS production ( p = 0.0008) compared to statically stored lungs at 4 °C and 10 °C. Functionally, ventilated lungs demonstrated improved respiratory mechanics with lower airway resistance ( p = 0.021) and increased compliance ( p = 0.023) compared to static storage at 10 °C. Ventilating lungs at 10 °C compared to static cold storage appears to result in healthier and more functional lung tissue and may extend the preservation times of donor organs for lung transplantation.
Hill et al. (Wed,) studied this question.