CRITICAL IMPORTANCE OF THE FIRST 10 MINUTES OF LUNG GRAFT REPERFUSIONAFTER HYPOTHERMIC STORAGE

Background. We have shown previously that lung graft function can be i mproved by achieving reperfusion with stepwise increments of perfusion pressure over 60 minutes. This study aimed to establish whether simil ar benefit could be achieved with a shorter, simpler protocol and diff erent storage conditions. Methods. Rat lungs were flushed with Univers ity of Wisconsin or modified Euro-Collins solution and reperfused for 1 hour with blood from a support animal. Grafts were reperfused immedi ately or after storage at 4 degrees C for 24 hours (University of Wisc onsin solution) or 6 hours (Euro-Collins solution). Stored-graft reper fusion was initiated with a 0-, 5-, or 10-minute period during which r eperfusion pressure was reduced by 50%. Results. Stored grafts receivi ng 0 or 5 minutes of initial low-pressure reperfusion performed poorly , with reduced oxygenation and blood flow and elevated pulmonary arter y pressure, airway pressure, and wet/dry weight ratio. In contrast, 10 minutes of initial 50%-pressure reperfusion yielded function comparab le with that in controls with both storage conditions. Conclusions. An initial 10-minute period of 50%-pressure reperfusion improves the fun ction of stored rat lung grafts, whereas 5 minutes is insufficient.