Prone ex vivo lung perfusion protects human lungs from reperfusion injury

• Published in: Artificial organs 2022-11, Vol.46 (11), p.2226-2233
• Main Authors: Niikawa, Hiromichi, Okamoto, Toshihiro, Ayyat, Kamal S., Itoda, Yoshifumi, Sakanoue, Ichiro, Farver, Carol F., Yun, James J., McCurry, Kenneth R.
• Format: Article
• Language: English
• Subjects: Cold storage; Cryopreservation; Cytokines; Inflammation; lobar lung function; Lobes; lower lobes; lung positioning; lung preservation; Lungs; marginal donor lungs; Oxygen; Partial pressure; Patient positioning; Perfusion; Reperfusion; Respiratory function; Supine position; Tumor necrosis factor-α
• ISSN: 0160-564X; 1525-1594
• DOI: 10.1111/aor.14328

Background We previously reported beneficial effects of prone positioning during ex vivo lung perfusion (EVLP) using porcine lungs. In this study, we sought to determine if prone positioning during EVLP was beneficial in human donor lungs rejected for clinical use. Methods Human double lung blocs were randomized to prone EVLP (n = 5) or supine EVLP (n = 5). Following 16 h of cold storage at 4°C and 2 h of cellular EVLP in either the prone or supine position. Lung function, compliance, and weight were evaluated and transplant suitability determined after 2 h of EVLP. Results Human lungs treated with prone EVLP had significantly higher partial pressure of oxygen/fraction of inspired oxygen (P/F) ratio [348 (291–402) vs. 199 (191–257) mm Hg, p = 0.022] and significantly lower lung weight [926(864–1078) vs. 1277(1029–1483) g, p = 0.037] after EVLP. 3/5 cases in the prone group were judged suitable for transplant after EVLP, while 0/5 cases in the supine group were suitable. When function of upper vs. lower lobes was evaluated, prone EVLP lungs showed similar P/F ratios and inflammatory cytokine levels in lower vs. upper lobes. In contrast, supine EVLP lungs showed significantly lower P/F ratios [68(59–150) vs. 467(407–515) mm Hg, p = 0.012] and higher tissue tumor necrosis factor alpha levels [100.5 (46.9–108.3) vs. 39.9 (17.0–61.0) ng/ml, p = 0.036] in lower vs. upper lobes. Conclusions Prone lung positioning during EVLP may optimize the outcome of EVLP in human donor lungs, possibly by improving lower lobe function. In this study, we sought to determine if prone positioning during ex vivo lung perfusion (EVLP) was beneficial in human donor lungs rejected for clinical use. Prone EVLP lungs showed similar P/F ratios and wet/dry ratio in lower vs. upper lobes. In contrast, supine EVLP lungs showed significantly lower P/F ratios and higher wet/dry ratio in lower vs. upper lobes. Prone EVLP may optimize the outcome of EVLP in human donor lungs, possibly by improving lower lobe function.