Normothermic ex vivo lung perfusion (EVLP) allows for assessment and reconditioning of donor lungs. Although a leukocyte filter (LF) is routinely incorporated into the EVLP circuit; its efficacy remains to be determined. Twelve pig lungs were perfused and ventilated ex vivo in a normothermic state for 12 hours. Lungs (n = 3) were allocated to four groups according to perfusate composition and the presence or absence of a LF in the circuit (acellular ± LF, cellular ± LF). Acceptable physiologic lung parameters were achieved during EVLP; however, increased amounts of pro-inflammatory cytokines (TNF-α and IL-6) and leukocytes in the perfusate were observed despite the presence or absence of a LF. Analysis of cells washed off the LF demonstrates that it trapped leukocytes although being ineffective throughout perfusion as it became saturated over 12 hours of EVLP. We conclude that there is no objective evidence to support the routine incorporation of a LF during EVLP as it does not provide further benefit and its removal does not appear to cause harm. The lack of hypothesized benefit to a LF may be because of the saturation of the LF with donor leukocytes, leading to similar amounts of circulating leukocytes still present in the perfusate with and without a LF.
From the *Division of Cardiac Surgery, Department of Surgery, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada; †Mazankowski Alberta Heart Institute, Edmonton, Canada; ‡Division of Cardiology, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada; §Cardiovascular Research Centre, Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada; ¶Division of Cardiovascular Surgery, Tohoku University Graduate School of Medicine, Sendai, Japan; ‖Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Canada; #Alberta Transplant Institute, Edmonton, Canada; and **Canadian National Transplant Research Program, Edmonton, Canada.
Submitted for consideration August 2016; accepted for publication in revised form February 2017.
Disclosure: The authors have no conflicts of interest to report.
This study was funded by the Alberta Transplant Institute (ATI), the University Hospital Foundation (UHF), and the Canadian Institutes of Health Research – Canadian National Transplant Research Program (CIHR – CNTRP). J G.Y. L – American Association of Thoracic Surgery Summer Intern Scholarship and the Alberta Innovates Health Solutions Summer Studentship. The funding organization had no role in the collection of data, its analysis and interpretation, or in the right to approve or disapprove the publication.
Correspondence: Jayan Nagendran, Division of Cardiac Surgery, Department of Surgery, University of Alberta and Mazankowski Alberta Heart Institute, 4-108A Li Ka Shing Health Research Centre, Edmonton, AB, T6G 2E1, Canada. Email: firstname.lastname@example.org.