Prone ex vivo lung perfusion protects human lungs from reperfusion injury
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.
CET Conclusion
| Reviewer: | Mr Simon Knight, Centre for Evidence in Transplantation, Nuffield Department of Surgical Sciences University of Oxford |
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| Conclusion: | The small experimental study randomised 10 double-lung blocks declined for transplant to either prone ex-vivo perfusion (EVLP) or supine EVLP. EVLP was continued for 2 hours, following which lung function, compliance and weight were assessed ex-vivo. The authors report that function was improved, and weight lower, in the prone group, with 3/5 lung blocks deemed suitable for transplant compared to none in the supine group. These findings are very interesting, but there are of course some limitations. Declined organs are likely to have different characteristics and a greater degree of variability in quality than those utilised for transplant, and in such a small sample there is the possibility of a type 1 error. As none of the lungs were transplanted, it is not clear whether the improvement in ex-vivo assessment would translate to improved clinical outcomes. However, the results do support further evaluation of prone EVLP in clinical studies of lungs intended for transplantation. |
Methodological quality
| Jadad score | 2 |
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| Allocation concealment | NO |
| Data analysis | PER PROTOCOL |
Study Details
| Aims: | This study aimed to assess whether prone positioning during EVLP was advantageous in human donor lungs declined for clinical transplant. |
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| Interventions: | Human double lung blocs were randomly assigned to either prone ex vivo lung perfusion (EVLP) or supine EVLP. |
| Participants: | 10 human double lung blocs rejected for clinical transplant. |
| Outcomes: | Lung function, compliance, weight and transplant suitability. |
| Follow Up: | Following 2 hours of EVLP. |
Metadata
| Funding: | No funding was received for this study |
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| Publication type: | Randomised Controlled Trial |
| Organ: | Lung |
| Language: | English |
| Author email: | hiromichi.niikawa.c3@tohoku.ac.jp |
| MeSH terms: | Animals; Humans; Lung; Lung Transplantation; Oxygen; Perfusion; Reperfusion Injury; Swine; S88TT14065 (Oxygen) |