Machine Perfusion of Donor Livers for Transplantation: A Proposal for Standardized Nomenclature and Reporting Guidelines

Abstract

With increasing demand for donor organs for transplantation, machine perfusion (MP) promises to be a beneficial alternative preservation method for donor livers, particularly those considered to be of suboptimal quality, also known as extended criteria donor livers. Over the last decade, numerous studies researching MP of donor livers have been published and incredible advances have been made in both experimental and clinical research in this area. With numerous research groups working on MP, various techniques are being explored, often applying different nomenclature. The objective of this review is to catalog the differences observed in the nomenclature used in the current literature to denote various MP techniques and the manner in which methodology is reported. From this analysis, we propose a standardization of nomenclature on liver MP to maximize consistency and to enable reliable comparison and meta‐analyses of studies. In addition, we propose a standardized set of guidelines for reporting the methodology of future studies on liver MP that will facilitate comparison as well as clinical implementation of liver MP procedures.

Organ Preservation into the 2020s: The Era of Dynamic Intervention

“…Terms such as hypothermic, subnormothermic, or normothermic were frequently used to describe perfusion temperatures, and the absence of a standardized criterion to describe technical details led to great heterogeneity between studies. In 2016, a group of distinguished researchers in the field of liver preservation proposed a nomenclature of perfusion temperature ranges that facilitates the comparison of different studies, meta-analysis realization, and criteria homogenization [113]. Much work in this area has focused on liver perfusion, although the same broad concepts apply to other organs.…”

“…The proposed cutoff point for HMP at 12°C is supported by the observation of numerous energy-dependent reactions of mitochondrial liver enzymes which exhibit significant rate changes at this temperature [113]. …”

“…In view of the fact that the broad range of temperatures, between 12 and 33°C, shows a great difference in the rate of metabolism, Karangwa et al [113] considered more appropriate to subdivide this interval and proposed the term midthermic machine perfusion.…”

Perfusion machines and hepatocellular carcinoma: a good match between a marginal organ and an advanced disease?

“…Ex situ perfusion of donor livers, both in clinical o r e x p e r i m e n t a l a c t i v i t i e s , c a n b e p e r f o r m e d a t four different temperature ranges: (I) hypothermia (41). Studies using HMP are generally performed at temperatures ranging from 4 to 10 ℃ in order to decrease metabolism and enzymatic reactions rate in mammalian cells as low as 20% or less (42,43).…”

The first case of ischemia-free organ transplantation in humans: A proof of concept

“…He is to be commended for this great achievement, which we consider a milestone in the history of organ transplantation. Even though the field of ex‐situ machine perfusion in organ transplantation is rapidly emerging, all currently used protocols still include periods of cold or warm ischemia before and after the period of machine perfusion 2. With their innovative surgical technique, He and colleagues have demonstrated that organ transplantation can be performed without any meaningful ischemia‐reperfusion (IR) injury, and they have taken machine perfusion to a different level.…”