The Effects of Oxygenation on Ex Vivo Kidneys Undergoing Hypothermic Machine Perfusion

Ischemia-reperfusion injury (IRI) constitutes a significant source of morbidity and mortality after orthotopic liver transplantation (OLT). The allograft is metabolically impaired during warm and cold ischemia and is further damaged by a paradox reperfusion injury after revascularization and reoxygenation. Short-term and long-term complications including post-reperfusion syndrome, delayed graft function, and immune activation have been associated with IRI. Due to the current critical organ shortage, extended criteria grafts are increasingly considered for transplantation, however, with an elevated risk to develop significant features of IRI. In recent years, ex vivo machine perfusion (MP) of the donor liver has witnessed significant advancements. Here, we describe the concept of hypothermic (oxygenated) machine perfusion (HMP/HOPE) approaches and highlight which allografts may benefit from this technology. This review also summarizes clinical applications and the main aspects of ongoing randomized controlled trials on hypothermic perfusion. The mechanistic aspects of IRI and hypothermic MP—which include tissue energy replenishment, optimization of mitochondrial function, and the reduction of oxidative and inflammatory damage following reperfusion—will be comprehensively discussed within the context of current preclinical and clinical evidence. Finally, we highlight novel trends and future perspectives in the field of hypothermic MP in the context of recent findings of basic and translational research.

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A simple ex vivo model of human renal allograft preservation using the gonadal vein

Annals of The Royal College of Surgeons of England ◽

10.1308/rcsann.2019.0107 ◽

2019 ◽

Vol 101 (8) ◽

pp. 609-616

Author(s):

WP Ries ◽

Y Marie ◽

K Patel ◽

C Turnbull ◽

TB Smith ◽

...

Keyword(s):

Cold Storage ◽

Organ Preservation ◽

Caspase 3 ◽

Ex Vivo ◽

Human Model ◽

Machine Perfusion ◽

Flow Conditions ◽

Ex Vivo Perfusion ◽

Gonadal Vein ◽

Hypothermic Machine Perfusion

Introduction Hypothermic machine perfusion, an organ preservation modality, involves flow of chilled preservation fluid through an allograft’s vasculature. This study describes a simple, reproducible, human model that allows for interrogation of flow effects during ex vivo organ perfusion. Materials and methods Gonadal veins from deceased human renal allografts were subjected to either static cold storage or hypothermic machine perfusion for up to 24 hours. Caspase-3, Krüppel-like factor 2 expression and electron microscopic analysis were compared between ‘flow’ and ‘no-flow’ conditions, with living donor gonadal vein sections serving as negative controls. Results The increase in caspase-3 expression was less pronounced for hypothermic machine-perfused veins compared with static cold storage (median-fold increase 1.2 vs 2.3; P < 0.05). Transmission electron microscopy provided ultrastructural corroboration of endothelial cell apoptosis in static cold storage conditions. For static cold storage preserved veins, Krüppel-like factor 2 expression diminished in a time-dependent manner between baseline and 12 hours (P < 0.05) but was abrogated and reversed by hypothermic machine perfusion (P < 0.05). Conclusions Our methodology is a simple, reproducible and successful model of ex vivo perfusion in the context of human organ preservation. To demonstrate the model’s utility, we establish that two widely used markers of endothelial health (caspase-3 and Krüppel-like factor 2) differ between the flow and no-flow conditions of the two predominant kidney preservation modalities. These findings suggest that ex vivo perfusion may mediate the induction of a biochemically favourable endothelial niche which may contribute tohypothermic machine perfusion’s association with improved renal transplantation outcomes.

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Machine Perfusion of the Liver: A Review of Clinical Trials

Frontiers in Surgery ◽

10.3389/fsurg.2021.625394 ◽

2021 ◽

Vol 8 ◽

Author(s):

Nikolaos Serifis ◽

Rudy Matheson ◽

Daniel Cloonan ◽

Charles G. Rickert ◽

James F. Markmann ◽

...

Keyword(s):

Clinical Trials ◽

Animal Studies ◽

Ex Vivo ◽

Machine Perfusion ◽

Advantages And Disadvantages ◽

Hypothermic Machine Perfusion ◽

Normothermic Machine Perfusion ◽

Novel Strategy ◽

Liver Machine Perfusion

Although efforts have been made by transplant centers to increase the pool of available livers by extending the criteria of liver acceptance, this practice creates risks for recipients that include primary non-function of the graft, early allograft dysfunction and post-operative complications. Donor liver machine perfusion (MP) is a promising novel strategy that not only decreases cold ischemia time, but also serves as a method of assessing the viability of the graft. In this review, we summarize the data from liver machine perfusion clinical trials and discuss the various techniques available to date as well as future applications of machine perfusion. A variety of approaches have been reported including hypothermic machine perfusion (HMP) and normothermic machine perfusion (NMP); the advantages and disadvantages of each are just now beginning to be resolved. Important in this effort is developing markers of viability with lactate being the most predictive of graft functionality. The advent of machine perfusion has also permitted completely ischemia free transplantation by utilization of in situ NMP showed promising results. Animal studies that focus on defatting steatotic livers via NMP as well as groups that work on regenerating liver tissue ex vivo via MP. The broad incorporation of machine perfusion into routine clinical practice seems incredible.

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Hypothermic machine perfusion with metformin-University of Wisconsin solution for ex vivo preservation of standard and marginal liver grafts in a rat model

World Journal of Gastroenterology ◽

10.3748/wjg.v23.i40.7221 ◽

2017 ◽

Vol 23 (40) ◽

pp. 7221-7231 ◽

Cited By ~ 4

Author(s):

Yi-Chao Chai ◽

Guo-Xin Dang ◽

Hai-Qi He ◽

Jian-Hua Shi ◽

Hong-Ke Zhang ◽

...

Keyword(s):

Rat Model ◽

Ex Vivo ◽

Machine Perfusion ◽

University Of Wisconsin Solution ◽

University Of Wisconsin ◽

Hypothermic Machine Perfusion ◽

Wisconsin Solution

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High Oxygen Pressure during Continuous Hypothermic Machine Perfusion is Associated with a Better Ex Vivo Renal Blood Flow and Early Graft Function in a Porcine DCD Auto-Transplant Model

Transplantation Journal ◽

10.1097/01.tp.0000543661.39716.31 ◽

2018 ◽

Vol 102 ◽

pp. S701

Author(s):

Tom Darius ◽

Pierre Gianello ◽

Antoine Buemi ◽

Martine de Meyer ◽

Michel Mourad

Keyword(s):

Blood Flow ◽

Renal Blood Flow ◽

Oxygen Pressure ◽

Ex Vivo ◽

Graft Function ◽

Machine Perfusion ◽

Hypothermic Machine Perfusion ◽

High Oxygen Pressure ◽

Early Graft ◽

Transplant Model

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Development of ex vivo normothermic perfusion as an innovative method to assess pancreases after preservation

Journal of the Nuffield Department of Surgical Sciences ◽

10.37707/jnds.v2i4.198 ◽

2021 ◽

Vol 2 (4) ◽

Author(s):

Ann Ogbemudia

Keyword(s):

Cold Storage ◽

Ex Vivo ◽

Gas Analysis ◽

Machine Perfusion ◽

Assessment Strategy ◽

Hypothermic Machine Perfusion ◽

Normothermic Perfusion ◽

Pancreas Preservation ◽

Normothermic Machine Perfusion ◽

Lactate Levels

Ann Ogbemudia, Julien Branchereau (Joint first authors), Gabriella Hakim, Fungai Dengu, FaysalEl-Gilani, John Mulvey, Kaithlyn Rozenberg, Thomas Prudhomme, Letizia Lo Faro, James Hunter,Paul Johnson, Rutger Ploeg and Peter Friend Objective Static cold storage (SCS) is the standard method for pancreas preservation but does not facilitate objective organ assessment prior to transplantation. Normothermic machine perfusion (NMP) has been used to test other abdominal and thoracic organs’ function and viability in transplantation settings. Our aim was to develop a NMP protocol specific for pancreases and then investigate its potential as an organ assessment strategy. Method 8 porcine pancreases were procured in conditions replicating donation after circulatory death with warm ischaemia time of 25 minutes. After 3 hours of static cold storage (SCS) the pancreases were divided into 3 experimental groups 1) the feasibility group (n=2) that underwent 2.5 hours of NMP 2) the SCS group (n = 2) that underwent an additional 6 hours of SCS prior to assessment on NMP for an hour and 3) the Oxygenated Hypothermic Machine Perfusion (oxyHMP) group (n = 4) that underwent 6 hours of oxyHMP followed by 1-hour assessment on NMP. The NMP protocol used autologous, leucodepleted blood delivered at a mean arterial pressure of 40mmHg with a temperature of 37oC. At timed intervals during NMP, perfusate samples were collected for gas analysis and perfusion parameters were recorded. Results The feasibility group was used to develop the NMP protocol and demonstrated stable perfusion parameters throughout NMP. Compared to the SCS group the oxyHMP group demonstrated better average perfusion characteristics with lower resistances, higher flow rates, lower mean lactate levels and physiological pH. The oxyHMP group maintained normal macroscopic appearances during NMP. At the end of NMP the SCS group had an average 32% weight increase compared to the oxyHMP group that were found to have a 17% weight reduction. Conclusion Normothermic machine perfusion of whole pancreases is feasible after cold preservation and potentially useful as an assessment strategy. Furthermore, it demonstrated that oxygenated HMP may be beneficial for pancreas preservation compared to SCS.

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