Evaluation of Ventilation at 10°C as the Optimal Storage Condition for Donor Lungs in a Murine Model

Cold static preservation at 4°C is the clinical standard for donor lung storage but is limited to 6-8 hours 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 24h 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.