Title Comparison of extracellular-type-kyoto solution and perfadex as a preservation solution in a pig ex vivo lung perfusion model: impact of potassium level

Title: Comparison of ET-Kyoto Solution and Perfadex as a Preservation Solution in a Pig Ex Vivo Lung Perfusion Model: Impact of Potassium Level Bachground. The ex vivo lung-perfusion (EVLP) system has successfully been used for assessing donor lungs. Perfadex (PX) is usually used as the flush and preservation solution in EVLP system. We have used the extracellular-type-Kyoto (ET-K) solution containing 44 mEq/L potassium in clinical lung transplantation and investigated whether the use of this solution instead of PX affects the EVLP system. Methods. We used domestic pigs from a slaughterhouse and analyzed the EVLP system. After 20-min warm ischemia and 6-h cold ischemia, EVLP was performed for 2 h. Pig heart-lung blocks were classified into the PX (n = 5) and ET-K (n = 5) groups depending on the flush and cold preservation solution. At the beginning, we discarded the first 100 ml of effluent in the PX group and the first 200 ml in the ET-K group. Pulmonary physiological data and potassium levels were measured. Results. In both groups, perfusion was carried out for 2 h. The 2 groups did not differ with respect to the final flow, pulmonary arterial pressure, pulmonary vascular resistance, PaO2/FiO2, and shunt fraction. The potassium level of the perfusate was 4.4 mEq/L in the PX group and 5.4 mEq/L in the ET-K group. Conclusion. The pig EVLP system was not affected when ET-K was used instead of PX as the flush and preservation solution. The initial 200 ml of effluent should be discarded when using the ET-K to ensure that the potassium level does not increase. Abstract