The impact of perfusate filtration or exchange on lung function during ex vivo lung perfusion (EVLP): a systematic review.

Background: Ex vivo lung perfusion (EVLP) supports assessment and rehabilitation of donor lungs. It runs as a closed circuit, so electrolytes and metabolites accumulate over the duration of perfusion. This systematic review investigates the impact of various dialysis or perfusate exchange (PE) techniques on electrolyte balance, inflammation and lung function during EVLP. Methods: A literature search of PubMed and Embase was conducted from database inception to September 17, 2025. We included all articles describing human or animal studies that tested dialysis or PE during EVLP. Outcomes included electrolytes, lactate, pH, edema formation, lung performance characteristics, and inflammatory markers. Results: Five studies met the inclusion criteria, one human and four porcine models, with a total of 57 subjects. Across studies, dialysis consistently improved solute clearance, lowering sodium, potassium, and chloride, while increasing calcium and glucose, reducing lactate accumulation, and maintaining physiologic pH. PE did not sustain physiologic pH and had limited impact on electrolyte homeostasis, with only transient effects on lactate. No differences were observed in lung function parameters including oxygenation, compliance, and airway pressure. Pro-inflammatory cytokine production was largely unchanged, however, interleukin (IL)-10 was elevated with dialysis in several studies. Conclusion: During EVLP, dialysis stabilized acid-base status and metabolites. These biochemical gains did not translate into consistent improvements in oxygenation or compliance. Smaller dialysis membranes were associated with higher pulmonary artery pressure (PAP) and increased cytokine profile. Future studies should extend EVLP duration with perfusate clearance to evaluate whether perfusate clearance strategies provide additional benefits with longer duration preservation.