Temperature dynamics of donor lungs from procurement to reperfusion: Static ice versus controlled hypothermic storage

Ischemia-reperfusion injury (IRI) remains an important challenge in lung transplantation (LTx). Ischemia can be divided into 3 phases: cooling during procurement, preservation, and rewarming during implantation. Temperature fluctuations influence metabolic processes, exacerbating IRI. However, actual lung temperatures have not been previously studied. Therefore, we aimed to characterize lung temperature dynamics in clinical LTx for static ice storage (SIS) and controlled hypothermic storage (CHS).

From December 2022 to February 2024, we included 35 SIS and 19 CHS bilateral LTx cases at a single center, resulting in 70 SIS and 38 CHS lungs. Surface temperature (surfaceT°) was measured with a thermography camera. Preservation temperature (preservationT°) was remotely recorded for 6 SIS and 6 CHS. Core temperature (coreT°) was measured with a flexible probe in the lower lobe bronchus after unpacking and every 10 minutes during implantation.

Regarding SIS, mean ± standard deviation (SD) surfaceT° was 30°C ± 3.3°C before flushing, 17°C ± 4.1 °C after extraction, 8.6°C ± 3.3°C before packing. PreservationT° reached 4°C after 98 minutes and 0°C after 266 minutes. After unpacking, surfaceT° was 1.8°C ± 2.3°C, coreT° was 1.6°C ± 1.2°C. At 30 minutes implantation, surfaceT° was 25.0°C ± 2.9°C, coreT° was 22.0°C ± 4.4°C. CHS surfaceT° was 30.0°C ± 2.5°C before flushing, 17°C ± 3.8°C after extraction, and 11°C ± 3.5°C before packing. After unpacking, surfaceT° was 7.9°C ± 2.0°C, and coreT° was 7.1°C ± 1.1°C. At 30 minutes of implantation, surfaceT° was 26.0°C ± 1.7°C, and coreT° was 24.0°C ± 3.6°C. Postoperative outcome was comparable between both groups.

We characterized temperature dynamics in clinical LTx, revealing a rapid temperature drop with pulmonary flushing, potential freezing injury with SIS, and rapid rewarming during implantation.