Hypothermic Machine Perfusion of the Liver: Is It More Complex than for the Kidney?

doi:10.1016/j.transproceed.2011.09.033

Transplantation Proceedings

Volume 43, Issue 9, November 2011, Pages 3445-3450

https://doi.org/10.1016/j.transproceed.2011.09.033 Get rights and content

Abstract

Background

Hypothermic machine perfusion (HMP) is superior to simple cold storage (SCS) for the preservation of kidney grafts. Whether HMP is superior to SCS for liver preservation is not known. Before a HMP system can be used clinically for the liver, its superiority to SCS needs to be demonstrated in an in vivo large animal transplant model.

Objective

The aim was to compare outcomes after liver transplantation (LT) following preservation by SCS or HMP using technology/perfusion conditions similar to those for kidney HMP.

Methods

Pig livers were perfused via the hepatic artery and portal vein for 4 hours with nonoxygenated 4°C University of Wisconsin machine perfusion solution. In the SCS group, flushed livers were stored in histidine-tryptophan-ketoglutarate solution. After preservation by SCS (n = 6) or HMP (n = 8) and LT, we assessed graft and recipient survivals, pH and lactate, hepatocellular damage [aspartate aminotransferase (AST)], Kupffer cell activation (β-galactosidase), tumor necrosis factor (TNF) α production, endothelial cell function (hyaluronic acid), and expression of Krüppel-like factor (KLF) 2 and 4, which are mediators of the flow-dependent vasoprotective endothelial phenotype.

Results

No primary graft nonfunction was observed; livers recovered equally well from the postanhepatic metabolic acidosis in both groups. Pig survival was 5/6 (83%) in the SCS versus 2/8 (12.5%) in the HMP group (P = .04). Livers from both groups recovered equally well from the postanhepatic metabolic acidosis. AST in liver rinse-out samples obtained before LT were lower in the HMP than in the SCS group (P < .05). After reperfusion, AST and β-galactosidase were equally increased in both groups (P = .13 and 0.962, respectively); TNF-α and hyaluronic acid levels were higher after HMP versus SCS (P = .001 and 0.043, respectively). KLF-2 and -4 expressions were equally up-regulated after reperfusion in the SCS and HMP groups.

Conclusions

In this in vivo model, liver HMP with subsequent transplantation was feasible. However, we did not demonstrate an advantage of HMP, using perfusion conditions shown to be effective for the kidney, over SCS. Despite similar immediate graft function, TNF-α generation, and endothelial cell dysfunction were more pronounced after HMP.

Section snippets

Animal Model

Fourteen inbred Landrace pigs (25–30 kg) were used as donors and another 14 as recipients. After standard procurement, donor livers preserved by either HMP (n = 8) or SCS (n = 6) for 4 hours were transplanted into size-matched recipients, as described previously.⁵ We recorded graft function and 3-day survival. Hemodynamic stability was achieved through adequate fluid management throughout the first 3 hours after reperfusion. Bile drained into a collection bag was readministered into the

Graft Function and Survival

No primary graft nonfunction was observed in either group; all livers displayed immediate graft function. After transplantation, all recipients were weaned from the ventilator. In the HMP group, 5 recipients died within 24 hours, and 1 other within 48 hours, all without a clear cause identified at autopsy. Recipient survival at POD 3 was 5/6 (83%) in the SCS versus 2/8 (25%) in the HMP group. The survival rate after LT was significantly different between the SCS and HMP groups (P = .04).

Biochemical Parameters in Blood

Livers

Discussion

Machine perfusion preservation seeks to bridge the time between organ procurement and transplantation. It was developed together with the first clinical transplantations but was later abandoned in most centers because of its complexity compared with SCS. With the increased use of higher-risk organs and the development of simple less cumbersome HMP systems, machine perfusion has regained in interest. The superiority of HMP over SCS, using well established protocols and perfusion settings, has

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H<inf>2</inf>S supplementation: A novel method for successful organ preservation at subnormothermic temperatures
2018, Nitric Oxide - Biology and Chemistry
Citation Excerpt :
To limit these negative effects, hypothermic machine perfusion (HMP), where the donor organ is continuously perfused with preservation solution, was introduced [16]. While the increased distribution of nutrients and the clearance of toxic metabolites with HMP are perceived benefits, studies comparing HMP to SCS are inconsistent [19–22]. There are additional drawbacks to HMP, such as expense and complexity, that make this approach less feasible than SCS [21,23].
Renal transplantation is the preferred treatment for end-stage renal disease. Currently, there is a large gap between the supply and demand for transplantable kidneys. The use of sub-optimal grafts obtained via donation after cardiac death (DCD) is on the rise. While static cold storage (SCS) in University of Wisconsin (UW) solution on ice (4°C) is the clinical standard of care for renal graft preservation, cold storage has been associated with negative graft outcomes. The alternative, normothermic machine perfusion, involves mechanical perfusion of the organ at physiological or normothermic temperature (37°C) and this technique is expensive, complicated and globally inaccessible. As such, simpler alternatives are of interest. Preliminary results revealed that UW solution is more protective at 21°C than 37°C and subnormothermic preservation is of interest because it may facilitate the use of existing solutions while preventing cold injury. We have previously shown that SCS in UW solution supplemented with mitochondria-targeted H₂S donor AP39 improves renal graft outcomes. As such, it was hypothesized subnormothermic preservation at 21°C with AP39 will also improve renal outcomes. Using an in vitro model of hypoxia and reoxygenation, we found that treating porcine tubular epithelial cells with UW+5 μM AP39 during 18 h hypoxia at 21°C significantly increased renal tubular epithelial cell viability after 24 h of reoxygenation at 37°C compared to UW alone. Also, AP39-supplemented UW solution was significantly more cytoprotective during hypoxia at 21°C than hypoxia at 37°C, regardless of AP39 concentration. Using an ex vivo DCD organ preservation model, we found that DCD porcine kidneys stored for 24 h in UW+200 nM AP39 at 21°C showed significantly lower tissue necrosis than DCD porcine kidneys preserved using SCS in UW solution, the clinical standard of care. Overall, our findings suggest that exogenous H₂S supplementation improves the viability of the gold standard organ preservation solution, UW solution, for subnormothermic preservation at 21°C.
Emerging Innovations in Liver Preservation and Resuscitation
2018, Transplantation Proceedings
The availability of marginal liver grafts represents a potential resource of orthotopic liver transplantation (OLT) in the era of organ shortage. However, an increased susceptibility to ischemia-reperfusion injury results in the increased risk for primary nonfunction and biliary complications. Novel methods of organ preservation and resuscitation are under investigation to improve outcomes of OLT with the use of marginal grafts. Machine perfusion (MP) in OLT is categorized based on the temperature setting. Hypothermic MP minimizes oxygen demand and uses single- or dual-vessel infusion with or without oxygenation. Normothermic MP increases the metabolic rate to the physiologic level, and requires dual-vessel infusion with a higher blood flow rate with oxygenation typically by blood as an oxygen carrier. Midthermic or subnormothermic MP uses medium temperature settings to allow metabolic activity to maintain cellular integrity as well as decrease oxygen demand. Since 2010, a total of 9 clinical trials have investigated the safety and feasibility of hypothermic and normothermic MP. The results suggest that the incidence of primary nonfunction was minimal even when marginal grafts were used. Organ preservation time could be reasonably increased. MP offers an opportunity to assess the viability and time to apply therapeutic interventions. This review highlights the history of MP, mechanisms of different temperature settings in MP, and recent large animal studies and clinical trials in OLT.
Oxygenated hypothermic machine perfusion after static cold storage improves endothelial function of extended criteria donor livers
2017, HPB
Citation Excerpt :
In previous studies, the shear stress regulatory effect of KLF2 has been shown to be flow-pattern specific.32 In cultured human endothelial cells, pulsatile flow with significant forward direction increased KLF2 expression, while oscillatory flow with little forward direction did not.33 Interestingly, our study demonstrates better preservation of the arterial endothelial cell morphology of HMP livers compared to SCS alone livers.
Lack of oxygen and biomechanical stimulation during static cold storage (SCS) of donor livers compromises endothelial cell function. We investigated the effect of end-ischemic oxygenated hypothermic machine perfusion (HMP) on endothelial cell function of extended criteria donor (ECD) livers.
Eighteen livers, declined for transplantation, were transported to our center using static cold storage (SCS). After SCS, 6 livers underwent two hours of HMP, and subsequent normothermic machine perfusion (NMP) to assess viability. Twelve control livers underwent NMP immediately after SCS. mRNA expression of transcription factor Krüppel-like-factor 2 (KLF2), endothelial nitric oxide synthase (eNOS), and thrombomodulin (TM) was quantified by RT-PCR. Endothelial cell function and injury were assessed by nitric oxide (NO) production and release of TM into the perfusate.
In HMP livers, mRNA expression of KLF2 (p = 0.043), eNOS (p = 0.028), and TM (p = 0.028) increased significantly during NMP. In parallel, NO levels increased during NMP in HMP livers but not in controls. At the end of NMP cumulative TM release was significantly lower HMP livers, compared to controls (p = 0.028).
A short period of two hours oxygenated HMP restores endothelial cell viability after SCS and subsequent normothermic reoxygenation of ECD livers.
Machine perfusion of donor livers for transplantation: A proposal for standardized nomenclature and reporting guidelines
2016, American Journal of Transplantation
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.
Extracorporeal Perfusion for Resuscitation of Marginal Grafts
2015, Transplantation of the Liver: Third Edition
Best temperature for static liver graft storage is 1°C
2013, Journal of Surgical Research
Citation Excerpt :
Any improvement in graft quality through optimization of liver preservation would increase the number of viable organs and thus favor successful transplants. With this aim, several approaches have been explored that include ameliorating the composition of the preservation solution [7,8], refining the preservation method, static storage, or continuous perfusion [7,9–11], using protective reperfusion solutions [12], and optimizing the storage temperature [13,14]. Hypothermia was the earliest method used to store organs for transplant.
The best storage temperature in liver transplantation remains an unsolved question.
After storage for 24 h in University of Wisconsin solution at +4°C, +1°C, or −0.5°C, rat livers were subjected, or not, to 15 min of warm ischemia, rinsed with Ringer lactate, and subsequently reperfused with oxygenated Krebs-Henseleit buffer.
In the presence of warm ischemia, for livers stored at +4°C, creatine kinase (CK) peaked at 21 ± 5 IU g⁻¹ h⁻¹, hepatic resistance at 34,700 ± 1500 dyn s cm⁻⁵, bile flow reached 18 ± 4 μL g⁻¹ h⁻¹ after 10 min, and oxygen consumption stabilized at about 25 μmol g⁻¹ h⁻¹ after 20 min. When livers were stored at +1°C, CK and hepatic resistance were lowered, bile production was 33 ± 6 μL g⁻¹ h⁻¹ (P < 0.05 versus +4°C), and oxygen consumption was 105 ± 10 μmol g⁻¹ h⁻¹ (P < 0.001). For livers stored at −0.5°C, results were not statistically different from those of the +1°C group except for bile flow, which was significantly lower. Without warm ischemia, the peak of CK (P = 0.015) and the peak hepatic resistance (P < 0.001) of the +4°C group were significantly increased compared with the +1°C or −0.5°C groups. However, no difference in bile flow or oxygen consumption was observed. The number of trypan blue-positive nonparenchymal cells (P = 0.003) and the gain in liver weight during the reperfusion (P = 0.015) were minimal after storage at +1°C.
Static storage at +1°C improved liver function compared with +4°C or −0.5°C. Main beneficial effect was observed with parameters reflecting sinusoidal cells injury.

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: Diethard Monbaliu and Jacques Pirenne hold a chair of the Centrale Afdeling voor Fractionering (CAF) Vilvoorde, Belgium.

: Supported by a grant from the Institute for the Promotion of Innovation by Science and Technology in Flanders (IWT-project 040350) and unrestricted educational grants from Roche and Astellas, Belgium. Katrien Vekemans was supported by “Fonds Wetenschappelijk Onderzoek (FWO)–Vlaanderen,” Brussels, Belgium.

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Organ transplantationHypothermic Machine Perfusion of the Liver: Is It More Complex than for the Kidney?

Abstract

Background

Objective

Methods

Results

Conclusions

Section snippets

Animal Model

Graft Function and Survival

Biochemical Parameters in Blood

Discussion

Am J Transplant

Transplant Proc

J Biol Chem

Am J Pathol

Transplant Proc

Transplant Proc

Transplant Proc

Organ transplantation
Hypothermic Machine Perfusion of the Liver: Is It More Complex than for the Kidney?