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Methaemoglobinaemia Can Complicate Normothermic Machine Perfusion of Human Livers

Lookup NU author(s): Dr Sam Tingle, Dr Ibrahim Ibrahim, Dr Emily ThompsonORCiD, Lucy BatesORCiD, Dr Ashwin Sivaharan, Dr Yvonne BuryORCiD, Rodrigo Figueiredo, Colin Wilson



This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).


© Copyright © 2021 Tingle, Ibrahim, Thompson, Bates, Sivaharan, Bury, Figuereido and Wilson.Background: Although liver normothermic machine perfusion is increasingly used clinically, there are few reports of complications or adverse events. Many centers perform liver NMP to viability test suboptimal grafts, often for prolonged periods. In addition, several researchers are investigating NMP as a drug delivery platform, which usually necessitates prolonged perfusion of otherwise non-viable liver grafts. We describe two instances of methaemoglobinaemia during NMP of suboptimal livers. Methods: The NMP of eight human livers rejected for transplantation is described. Methaemoglobinaeima developed in two; one perfused using generic Medtronic™ perfusion equipment and one using the OrganOx Metra®. Results: The first liver (53 years DBD) developed methaemoglobinaemia (metHb = 2.4%) after 13 h of NMP, increasing to metHb = 19% at 16 h. Another liver (45 years DBD) developed methaemoglobinaemia at 25 h (metHb = 2.8%), which increased to metHb = 28.2% at 38 h. Development of methaemoglobinaemia was associated with large reductions in oxygen delivery and oxygen extraction. Both livers were steatotic and showed several suboptimal features on viability testing. Delivery of methylene blue failed to reverse the methaemoglobinaemia. Compared to a matched cohort of steatotic organs, livers which developed methaemoglobinaemia showed significantly higher levels of hemolysis at 12 h (prior to development of methaemoglobinaemia). Conclusions: Methaemglobinaemia is a complication of NMP of suboptimal liver grafts, not limited to a single machine or perfusion protocol. It can occur within 13 h (a timepoint frequently surpassed when NMP is used clinically) and renders further perfusion futile. Therefore, metHb should be monitored during NMP visually and using blood gas analysis.

Publication metadata

Author(s): Tingle SJ, Ibrahim I, Thompson ER, Bates L, Sivaharan A, Bury Y, Figuereido R, Wilson C

Publication type: Article

Publication status: Published

Journal: Frontiers in Surgery

Year: 2021

Volume: 8

Print publication date: 01/01/2021

Online publication date: 28/01/2021

Acceptance date: 04/01/2021

Date deposited: 07/04/2021

ISSN (electronic): 2296-875X

Publisher: Frontiers Media S.A.


DOI: 10.3389/fsurg.2021.634777


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