Comparison between cellular and acellular perfusates for ex vivo lung perfusion in a porcine model

Abstract

Background: Ex vivo lung perfusion with acellular solutions is an established technique for assessing marginal donor lungs. We evaluated the utility of a blood-based lung preservation fluid as an alternative perfusate.

Methods: Donor lungs from 50-kg donation after cardiac death pigs (n = 24) were randomized into 3 groups: acellular, commercial blood-based, and Papworth-Blood. Physiologic function was evaluated using conventional markers of pulmonary vascular resistance, pulmonary compliance, lactate excretion, partial pressure of oxygen/fraction of inspired oxygen, and wet-to-dry ratios. The immunologic profile was assessed by fluorescence-activated cell sorting analysis of bronchoalveolar lavage and cells entrapped in the leucocyte filter. Cytokines were quantified using a commercial platform.

Results: No significant difference was noted in pulmonary vascular resistance (p = 0.26), compliance (p = 0.12), partial pressure of oxygen/fraction of inspired oxygen (p = 0.06) and wet-to-dry ratios (p = 0.26) between groups. There was no difference between the percentages of lymphocytes (p = 0.51), macrophages (p = 0.87), monocytes (p = 0.68), and dendritic cells (p = 0.65) in the leukocyte filters. Interleukin (IL)-1β (p = 0.36), IL-6 (p = 0.08), IL-8 (p = 0.64), and IL-18 (p = 0.14) were elevated in all groups. In bronchoalveolar lavage, IL-8 was significantly higher in the acellular group (p = 0.04). Electron microscopy cell characteristics were similar among the groups.

Conclusions: This study demonstrated no significant difference in the physiologic, immunologic, or ultrastructural parameters between lungs perfused with cellular or acellular solutions. The Papworth-Blood solution is a potential alternative perfusate for ex vivo lung perfusion.

Keywords: Ex vivo lung perfusion; cellular immunology; electron microscopy; lung transplantation; organ perfusion; perfusates.