Challenging the Ex Vivo Lung Perfusion Procedure With Continuous Dialysis in a Pig Model

Background. Normothermic ex vivo lung perfusion (EVLP) increases the pool of donor lungs by requalifying marginal lungs refused for transplantation through the recovery of macroscopic and functional properties. However, the cell response and metabolism occurring during EVLP generate a nonphysiological accumulation of electrolytes, metabolites, cytokines, and other cellular byproducts which may have deleterious effects both at the organ and cell levels, with impact on transplantation outcomes. Methods. We analyzed the physiological, metabolic, and genome-wide response of lungs undergoing a 6-h EVLP procedure in a pig model in 4 experimental conditions: without perfusate modification, with partial replacement of fluid, and with adult or pediatric dialysis filters. Results. Adult and pediatric dialysis stabilized the electrolytic and metabolic profiles while maintaining acid-base and gas exchanges. Pediatric dialysis increased the level of IL-10 and IL-6 in the perfusate. Despite leading to modification of the perfusate composition, the 4 EVLP conditions did not affect the gene expression profiles, which were associated in all cases with increased cell survival, cell proliferation, inflammatory response and cell movement, and with inhibition of bleeding. Conclusions. Management of EVLP perfusate by periodic replacement and continuous dialysis has no significant effect on the lung function nor on the gene expression profiles ex vivo. These results suggest that the accumulation of dialyzable cell products does not significantly alter the lung cell response during EVLP, a finding that may have impact on EVLP management in the clinic.

Automated summary

This study investigated the effects of normothermic ex vivo lung perfusion (EVLP) on the physiological, metabolic, and genome-wide response in a pig model. The results showed that the management of EVLP perfusate by periodic replacement and continuous dialysis had no significant effect on lung function nor on the gene expression profiles ex vivo, suggesting that the accumulation of dialyzable cell products does not significantly alter the lung cell response during EVLP, which has implications for EVLP management in the clinic.