Seventy-two-hour preservation of porcine liver by continuous hypothermic perfusion with UW solution in comparison with simple cold storage

Porcine livers preserved for 72 hr using continuous hypothermic perfusion (CHP) were studied in order to compare the effects of CHP on energy metabolism with those of simple cold storage (SCS). The livers of the CHP group were perfused in situ for 72 hr at 7 degrees C with University of Wisconsin (UW) solution and FC-43 as an oxygen carrier, while those of the S1 group were stored ex situ for 48 hr at 4 degrees C in UW solution, and those of the S2 group for 72 hr. They were then recirculated with human blood at 37 degrees C for 2 hr for the evaluation of their viability. At the end of preservation, significantly higher levels of total adenine nucleotides (TAN) and energy charge (EC) were observed in the CHP group compared with the S1 and S2 groups. At 2 hr recirculation, the level of TAN was significantly higher in the CHP group than in the S1 and S2 groups. The EC level was also higher in the CHP group than in the S2 group. During recirculation, the ketone body ratio (acetoacetate/beta-hydroxybutyrate) was higher in the CHP group than in the S2 group. The values in the CHP group were above 1.0 after 45 min recirculation. There were no significant differences in the pyruvate/lactate ratio and lactate level between the CHP and S1 groups. However, these values were significantly different from those in the S2 group. The present findings demonstrate that CHP using UW solution and the oxygen carrier was better able to preserve the energy metabolism of the porcine liver for 72 hr than 48-hr SCS in UW solution.     

Biochemical and metabolic assessments of liver graft preserved with oncotic oxygen carrier

The effect of an oxygen-carrying agent, as a component of the preservation solution, on the biochemical viability and energy metabolism of the graft in liver preservation was evaluated. Two preservation methods, simple hypothermic storage and continuous machine perfusion, both performed at 4°C for 48 h, were studied in male Lewis rats. Pyridoxylated hemoglobin-polyoxyethylene conjugate (PHP) was used as the oncotic oxygen carrier. University of Wisconsin (UW) solution served as a control solution. The test solution (PHP+UW) was a 1∶1 mixture of PHP and UW solutions with 4.0g% of hemoglobin. We observed that oxygen consumption during perfusion was significantly higher in the PHP+UW than in the UW group. Hepatic mitochondrial function and tissue adenosine-5′-triphosphate (ATP) levels were better preserved in the PHP+UW than in the UW group, and were also better preserved in continuous machine perfusion than in simple hypothermic storage. No significant differences were observed in perfusate biochemical parameters. These results indicate that the incorporation of an oxygen-carrying agent into preservation solution provides significantly better oxygen delivery to liver grafts, and may improve hepatic viability.     

Seventy-two-hour preservation of the canine liver by machine perfusion

The UW solution effectively preserves the dog liver for up to 48 hr by simple cold storage. This solution contains lactobionate as the primary impermeant. Another solution developed for machine perfusion of the kidney is similar to the UW solution but contains gluconate in place of lactobionate. In this study the UW gluconate solution was used for the continuous hypothermic machine perfusion of dog livers for 72 hr. Dog livers were continuously perfused at 5 degrees C through the portal vein at a pressure of 16-18 mm Hg and transplanted. Seven of 8 dogs survived for 7 or more days following orthotopic transplantation. The livers functioned as well as those preserved for 48 hr by cold storage in the UW solution as indicated by various liver-function tests. Successful machine perfusion was only achieved when the perfusate contained a high concentration of potassium (125 mM) but not with a high concentration of sodium (125 mM). This study demonstrates the feasibility of machine-perfusion preservation of the liver that yields longer preservation of equal quality compared to simple cold storage. For the development of truly long-term preservation (5 or more days) and better quality short-term preservation, machine perfusion may be the method of choice.     

Improved rat liver preservation by hypothermic continuous machine perfusion using polysol, a new, enriched preservation solution.

For experimental machine perfusion (MP) of the liver, the modified University of Wisconsin solution (UW-G) is most often used. In our search for an enriched MP preservation solution, Polysol was developed. Polysol is enriched with various amino acids, vitamins, and other nutrients for the liver metabolism. The aim of this study was to compare Polysol with UW-G for MP preservation of the liver. Rat livers were preserved during 24 hours with hypothermic MP using UW-G (n = 5) or Polysol (n = 5). Hepatocellular damage (aspartate aminotransferase [AST], alanine aminotransferase [ALT], lactate dehydrogenase [LDH], alpha-glutathione-S-transferase [alpha-GST]) and bile production were measured during 60 minutes of reperfusion (37 degrees C) with Krebs-Henseleit buffer. Control livers were reperfused after 24 hours of cold storage in UW (n = 5). MP using UW-G or Polysol showed less liver damage when compared with controls. Livers machine perfused with Polysol showed less enzyme release when compared to UW-G. Bile production was higher after MP using either UW-G or Polysol compared with controls. In conclusion, machine perfusion using Polysol results in better quality liver preservation than cold storage with UW and machine perfusion using UW-G.     

Rescue of the Cold Preserved Rat Liver by Hypothermic Oxygenated Machine Perfusion

The aim of the study was to investigate whether hypothermic oxygenated liver perfusion after cold liver preservation resuscitated metabolic parameters and whether this treatment had a benefit for liver viability upon reperfusion.
We preserved rat livers either by cold storage (UW) for 10 h, or by perfusion for 3 h (oxygenated modified UW) after 10 h cold storage. We assessed viability of livers after preservation and after ischemic rewarming + normothermic reperfusion ex vivo . Ten hour cold storage reduced mitochondrial cytochrome oxidase and metabolically depleted the livers. Oxygenated perfusion after cold storage resulted in uploaded cellular energy charge and oxidized mitochondrial cytochrome oxidase. Reperfusion after 10 h cold storage increased formation of superoxid anions, release of cytosolic LDH, lipid peroxidation, caspase activities and led to disruption of sinusoidal endothelial cells. In contrast, reperfusion after 10 h cold storage + 3 h hypothermic oxygenated perfusion resulted in no changes of lipid peroxidation, bile flow, energy charge, total glutathione, LDH release and of caspase activation, as compared to fresh resected livers.
This study demonstrates, that a metabolically depleted liver due to cold storage can be energy recharged by short-termed cold machine perfusion. The machine perfused graft exhibited improved viability and functional integrity.     

Preservation of bone graft vascularity with the University of Wisconsin cold storage solution

The preservation of the microcirculation of bone has been evaluated with use of an in vitro canine tibia perfusion model. The production of relaxing factors by the osseous vascular endothelium was used as a metabolic marker for viability. This endothelial eccrine function was preserved for 5 days (120 h) by cold storage without continuous perfusion after a washout with the University of Wisconsin (UW) solution. This synthetic perfusate was superior to Krebs Ringer solution (p < 0.05), but storage without perfusion failed to prevent a significant rise in vascular resistance. Two techniques were effective for the preservation of bone vascularity for 24 h: washout with UW solution followed by nonperfusion cold (4°C) storage, and vascular washout with mannitol solution followed by continuous hypothermic (5°C) microperfusion (0.03 ml/min) with UW solution. The most consistent, and lowest, vascular resistance was produced by the microperfusion technique. However, UW solution does not consistently prevent an increase in vascular resistance with hypothermic ischemia. This technique may prove useful for the preservation of vascularized bone grafts, but it needs to be evaluated in a transplantation model.     

The impact of liver preservation in HTK and UW solution on microcirculation after liver transplantation

Severe microcirculatory disturbances due to endothelial cell damage and leukocyte adherence during reperfusion of transplanted livers are considered to contribute to early graft failure. Since the degree of reperfusion injury after liver transplantation depends on the length of preservation time and the solution used for preservation, the aim of our study was to assess three solutions with respect to microvascular perfusion and leukocyte adhesion. Therefore, rat livers were stored up to 24 h in Euro-Collins (EC), University of Wisconsin (UW), or histidin-tryphtophan-ketoglutarate (HTK) solutions prior to orthotopic transplantation. The livers were studied in situ 60 min postoperatively using intravital fluorescence video microscopy. Using simple syringe flushing (10 ml), sinusoidal perfusion decreased below 50% in EC preserved livers after 8 h preservation, in HTK preserved livers after 16 h preservation, and remained higher than 70% in livers preserved in UW up to 24 h. Permanent adhesion of leukocytes was increased more rapidly in organs after 1, 8, 16, and 24 h preservation in HTK (16%, 15%, 34%, and 49.7% ± 4.7%) compared to those preserved in UW (15%, 18%, 17%; and 32.7% ± 3.3%; P < 0.05). Using a 10-fold volumn of the organ weight of HTK solution during the harvesting procedure, with an 8 min equilibration period, sinusoidal perfusion (39.6 ± 4.7%) and leukocyte adhesion (42.7 ± 3.1%) were not improved after 24 h. In contrast, equilibration with a volumn of approximately 40-times the liver weight improved sinusoidal perfusion (70.8% ± 2.7%; P < 0.01) and leukocyte adhesion (24.9% ± 3.1%; P < 0.01) significantly. Thus, using HTK solution, simple flushing prior to long-term cold storage resulted in microcirculatory disturbances when compared to UW solution. Larger volumns of HTK solution with an additional equilibration period of 8 min, however, reduced leukocyte adhesion and improved sinusoidal perfusion to a similar degree as UW solution.     

Machine perfusion preservation of the non-heart-beating donor rat livers using polysol, a new preservation solution

AIMS: The increasing shortage of donor organs has led to a focus on extended criteria donors, including the non-heart-beating donor (NHBD). An optimal preservation method is required to facilitate successful transplantation of these ischemically damaged organs. The recent literature has shown clear advantages of hypothermic machine perfusion (MP) over cold storage (CS). For MP, modified University of Wisconsin perfusion solution (UW-G) is often used, which, however, is known to cause microcirculatory obstruction, is difficult to obtain, and is expensive. Therefore, Polysol was developed as a MP preservation solution that contains specific nutrients for the liver, such as amino acids, energy substrates, and vitamins. The aim of this study was to compare Polysol with UW-G in a NHBD rat liver model. METHODS: After 24 hours hypothermic MP of NHBD rat livers using UW-G or Polysol, liver damage and function parameters were assessed during 60 minutes of reperfusion with Krebs-Henseleit buffer. Control livers were reperfused after 24 hours CS in UW. RESULTS: Liver enzyme release was significantly higher among the CS-UW group compared to MP using UW-G or Polysol. Flow during reperfusion was significantly higher when using Polysol compared to UW-G. Bile production and ammonia clearance were highest when using Polysol compared to UW-G. There was less cellular edema after preservation with Polysol compared to UW-G. CONCLUSIONS: MP of NHBD rat livers for 24 hours using UW-G or Polysol resulted in less hepatocellular damage than CS in UW. MP of NHBD livers for 24 hours using Polysol is superior to MP using UW-G.     

Maintenance of rat liver viability enhanced by cold flushing with oxygenated perfluorochemicals

The possible benefit of oxygenation during initial cold flushing was investigated as a means of improving the quality of liver preservation in rats. In five groups of animals (total 61 experiments), the livers were flushed with different perfusates. Non-oxygenated groups included controls, Collins’ solution alone and Collins’ solution containing perfluorotributylamine (FC-43). In the oxygenated groups, Collins’ solution alone and Collins’ solution containing FC-43 were oxygenated by bubbling. The hepatic ATP level and histopathological changes were used to assess the quality of liver preservation. Oxygenation during the initial cooling process proved to be effective in maintaining energy metabolism and preventing the characteristic microscopic changes of ischemic damage. Oxygenated Collins’ solution containing FC-43 showed a much longer lasting effect compared with oxygenated Collins’ solution alone, without FC-43. Under light microscopy, the integrity of the liver appeared to be well preserved up to eight hours with the former solution. It is concluded that enhanced oxygenation with FC-43 in the initial cold flushing period can improve the quality of liver preservation.     

Improved preservation of warm ischemic livers by hypothermic machine perfusion with supplemented University of Wisconsin solution.

Hypothermic machine perfusion (HMP) has the potential to improve recovery and preservation of Donation after Cardiac Death (DCD) livers, including uncontrolled DCD livers. However, current perfusion solutions lack the needed substrates to improve energy recovery and minimize hepatic injury, if warm ischemic time (WIT) is extended. This proof-of-concept study tested the hypothesis that the University of Wisconsin (UW) solution supplemented with anaplerotic substrates, calcium chloride, thromboxane A2 inhibitor, and antioxidants could improve HMP preservation and minimize reperfusion injury of warm ischemic livers. Preflushed rat livers subjected to 60 min WIT were preserved for 5 h with standard UW or supplemented UW (SUW) solution. Post preservation hepatic functions and viability were assessed during isolated perfusion with Krebs-Henseleit solution. Livers preserved with SUW showed significantly (p < .001) improved recovery of tissue ATP levels (micromol/g liver), 2.06 +/- 0.10 (mean +/- SE), as compared to the UW group, 0.70 +/- 0.10, and the level was 80% of that of fresh control livers (2.60 +/- 0.13). At the end of 1 h of rewarming, lactate dehydrogenase (U/L) in the perfusate was significantly (p < .05) lower in the SUW group (429 +/- 58) as compared to ischemia-reperfusion (IR) (781 +/- 12) and the UW group (1151 +/- 83). Bile production (microg/min/g liver) was significantly (p < .05) higher in the SUW group (280 +/- 13) as compared to the IR (224 +/- 24) and the UW group (114 +/- 14). The tissue edema formation assessed by tissue wet-dry ratio was significantly (p < .05) higher in UW group. Histology showed well-preserved hepatic structure in the SUW group. In conclusion, this study suggests that HMP with SUW solution has the potential to restore and preserve livers with extended WIT.     

Evaluation of kidney viability during hypothermic perfusion or cold storage

The effect of up to 6 days of hypothermic perfusion and up to 72 h of cold storage on tissue viability were studied from measurements of sodium potassium pump activity and adenosine nucleotide content. For the hypothermic perfusion two different albumin-based perfusates were used, one with, the other without addition of caprylic acid and amino acids. No difference could be found in the parameters studied between perfusion with these two perfusates. For both perfusates total adenine nucleotide content (TAN) decreased by approximately 60% during perfusion while energy charge potential (ECP) and the ATP/ADP ratio remained constant. During cold storage a decrease of both TAN and ECP and the ratio ATP/ADP was seen, the main decrease occurring within the 1st h. The transmembrane potassium influx as deduced from potassium content in incubated cortical slices during steady state conditions decreased during 6 days of hypothermic storage to 24.5 +/- 2.4 mumol/kg which was a significantly higher level than after 24 h of cold storage. Thus, addition of extra substrate to the perfusate does not seem to improve kidney cortex viability during hypothermic perfusion. Parenchymal viability is better preserved with continuous hypothermic perfusion, compared to simple cold storage in a solution of the same ionic composition as that used for perfusion.     

Delivery of the bioactive gas hydrogen sulfide during cold preservation of rat liver: effects on hepatic function in an ex vivo model

The insults sustained by transplanted livers (hepatectomy, hypothermic preservation, and normothermic reperfusion) could compromise hepatic function. Hydrogen sulfide (H₂S) is a physiologic gaseous signaling molecule, like nitric oxide (NO) and carbon monoxide (CO). We examined the effect of diallyl disulfide as a H₂S donor during hypothermic preservation and reperfusion on intrahepatic resistance (IVR), lactate dehydrogenase (LDH) release, bile production, oxygen consumption, bromosulfophthalein (BSP) depuration and histology in an isolated perfused rat liver model (IPRL), after 48 h of hypothermic storage (4°C) in University of Wisconsin solution (UW, Viaspan). Livers were retrieved from male Wistar rats. Three experimental groups were analyzed: Control group (CON): IPRL was performed after surgery; UW: IPRL was performed in livers preserved (48 h—4°C) in UW; and UWS: IPRL was performed in livers preserved (48 h—4°C) in UW in the presence of 3.4 mM diallyl disulfide. Hypothermic preservation injuries were manifested at reperfusion by a slight increment in IHR and LDH release compared with the control group. Also, bile production for the control group (1.32 µL/min/g of liver) seemed to be diminished after preservation by 73% in UW and 69% in UW H₂S group at the end of normothermic reperfusion. Liver samples analyzed by hematoxylin/eosin clearly showed the deleterious effect of cold storage process, partially reversed (dilated sinusoids and vacuolization attenuation) by the addition of a H₂S delivery compound to the preservation solution. Hepatic clearance (HC) of BSP was affected by cold storage of livers, but there were no noticeable differences between livers preserved with or without diallyl disulfide. Meanwhile, livers preserved in the presence of H₂S donor showed an enhanced capacity for BSP uptake (k_ACON = 0.29 min^?1; k_AUW = 0.29 min^?1; k_AUWS = 0.36 min^?1). In summary, our animal model suggests that hepatic hypothermic preservation for transplantation affects liver function and hepatic depuration of BSP, and implies that the inclusion of an H₂S donor during hypothermic preservation could improve standard methods of preparing livers for transplant.     

自制CMU-1液保存大鼠肝脏的实验研究

目的　探讨CMU 1液保存大鼠肝脏的效果。方法　根据灌注液和保存液的种类将Wistar大鼠分为两组 :UW组和CMU 1组 ,每组分 6h、12h、2 4h 3个保存时限 ,每亚组 6只大鼠。采用离体循环灌注模型 ,研究CMU 1保存液对保存肝脏能量代谢、生化功能、胆汁分泌及形态学方面的影响。结果　随着保存时间延长 ,肝组织TAN含量及AEC逐渐降低 ,CMU 1组较UW组下降略缓慢 ,保存 2 4h后高于UW组 (P <0 0 5 )。再灌注 12 0min后CMU 1组的肝脏分泌胆汁量较UW组多 (P <0 0 5 )。相同时限相比 ,灌出液中ALT、LDH值两组之间无显著差异 (P >0 0 5 )。肝脏组织学变化两组间无明显差异。保存 6h后 ,保存液pH值无明显变化 ;保存 12h后pH值下降 ,两组无明显差异 ;保存2 4h后 ,UW组pH值下降较CMU 1组明显。结论　CMU 1保存液保存大鼠肝脏效果与UW液相似 ,在改善保存肝脏能量代谢、预防细胞内酸中毒、胆汁分泌方面略优于UW液。     

自制HYD液对大鼠肝脏低温保存后生化功能影响的研究

目的 研制自制ＨＹＤ液对大鼠肝脏低温保存后生化功能的影响。方法 采用大鼠肝脏非循环离体灌注模型，比较ＨＹＤ液，ＵＷ液和乳酸林格液（ＬＲ液）对大鼠肝脏６，１２，２４，３０，３６ｈ保存后生化功能的影响。结果 保存１２ｈ的肝脏，其各项生化功能ＨＹＤ组明显优于ＬＲ组。三磷酸腺苷，磷酸腺苷含量及Ａｔｋｉｎｓｏｎ能荷（ＡＥＣ），ＨＹＤ组略高于ＵＷ组，且保存３６ｈ差异有显著性。     

UW solution for hypothermic machine perfusion of warm ischemic kidneys

BACKGROUND: Donation of kidneys from non-heart beating donors (NHBD) is increasingly being used to expand the donor pool. Warm ischemic injury of these kidneys suffered at harvest results in DGF at transplantation. In this study, we used hypothermic continuous machine perfusion preservation to mitigate this injury using two available solutions. METHODS: Dog kidneys (beagles) were exposed to 0, 60, or 75 min of in situ warm ischemia (37 degrees C), followed by 24 to 72 hr preservation by machine perfusion with Belzer MPS solution or the UW-solution (Viaspan). Auto-transplantation was performed with immediate contralateral nephrectomy. Survival and renal function (serum creatinine) were evaluated for up to 10 days posttransplant. RESULTS: Both solutions were equally effective for 72 hr machine perfusion preservation of dog kidneys giving 100% survival with only minor renal injury. Both solutions were also equally effective for preservation of kidneys exposed to 60 min of warm ischemia. However, only the UW solution gave reliable preservation (86% survival vs. 25% survival) in kidneys exposed to 75 min of warm ischemia and 24 hr machine perfusion. CONCLUSION: UW solution used with continuous hypothermic machine perfusion preservation can rescue canine kidneys from severe warm ischemic injury.     

A new transportable machine for the preservation of livers to be transplanted by means of hyperbaric oxygenation perfusion

The preservation of livers to be transplanted is currently obtained by static cold storage at 4 C degrees and flushing with UW solution. New methods of preservation are being studied that take advantage of machines for continuous hypothermic perfusion of the organ. Such machines have permitted a lengthening of preservation times and the use of livers from non-beating-heart donors. In an attempt to eliminate the damage due to hypothermia, to lengthen preservation times, and to extend the availability of livers to be transplanted, also using those subjected to short periods of warm ischaemia, we have constructed a transportable machine that produces a hyperbaric atmosphere and allows continuous perfusion of the liver. Ten pig livers from beating-heart donors were perfused with Ringer solution in hyperbaric conditions with oxygen at temperatures ranging from 10 to 25 degrees C for periods of up to 24 hours and studied by means of histopathological analysis and tests of mitochondrial activity (FAU) in order to verify cell viability. The group of livers perfused up to 15 hours yielded an FAU value of 169.40 +/- 5.5 compared to the value of the non-perfused livers (controls) established as 100 and those perfused up to 24 hours had a FAU value of 139.18 +/- 10.7 compared to the controls established as 100, thus demonstrating cell viability. The viability of the organs after preservation with our procedure in the hyperbaric oxygenation perfusion machine gives us good reason to believe that, after appropriate further confirmation of the results, it will be possible to use the machine for the transplantation both of livers subjected to warm ischaemia and of livers preserved for longer periods than is currently the case.     

Advantages of normothermic perfusion over cold storage in liver preservation

BACKGROUND: To minimize the ischemia-reperfusion injury that occurs to the liver with the current method of preservation and transplantation, we have used an extracorporeal circuit to preserve the liver with normothermic, oxygenated, sanguineous perfusion. In this study, we directly compared preservation by the standard method of simple cold storage in University of Wisconsin (UW) solution with preservation by perfusion. METHODS: Porcine livers were harvested from large white sows weighing between 30 and 50 kg by the standard procedure for human retrieval. The livers were preserved for 24 hr by either cold storage in UW solution (n=5) or by perfusion with oxygenated autologous blood at body temperature (n=5). The extracorporeal circuit used included a centrifugal pump, heat exchanger, and oxygenator. Both groups were then tested on the circuit for a 24 hr reperfusion phase, analyzing synthetic function, metabolic capacity, hemodynamics, markers of hepatocyte and reperfusion injury, and histology. RESULTS: Livers preserved with normothermic perfusion were significantly superior (P=0.05) to cold-stored livers in terms of bile production, factor V production, glucose metabolism, and galactose clearance. Cold-stored livers showed significantly higher levels of hepatocellular enzymes in the perfusate and were found to have significantly more damage by a blinded histological scoring system. CONCLUSIONS: Normothermic sanguineous oxygenated perfusion is a superior method of preservation compared with simple cold storage in UW solution. In addition, perfusion allows the possibility to assess viability of the graft before transplantation.     

Hemodynamic and biochemical changes during normothermic and hypothermic sanguinous perfusion of the porcine hepatic graft

Using an ex vivo liver sanguinous perfusion system, hemodynamic and biochemical changes of the porcine livers were studied, which were preserved cold (4 degrees C) for 24 hr in University of Wisconsin solution and reperfused with normothermic (37 degrees C) (n = 8) or hypothermic (32 degrees C) (n = 8) blood for 3 hr. Six more livers were reperfused with normothermic blood (37 degrees C) immediately after procurement as controls. The total hepatic blood flow was adjusted to 1 ml/min/g liver weight, in which hepatic artery and portal vein flows were administered at a 1:2 ratio. In livers stored cold for 24 hr in UW solution and perfused normothermically, a statistically higher hepatic artery resistance was exhibited at 30 and 60 min after reperfusion (P less than 0.05), and there was lower bile output (P less than 0.05) at 90 and 120 min as compared to the controls. In livers stored cold for 24 hr in UW solution and perfused hypothermically, as compared to ones perfused normothermically, statistically higher hepatic-artery and portal-vein resistances (P less than 0.05) were observed throughout the perfusion period and 60 min after reperfusion, respectively. In addition, bile output and oxygen consumption of these livers were statistically lower than those of ones perfused normothermically (P less than 0.05). In contrast, chemistries of the perfusate of livers perfused hypothermically were comparable to ones perfused normothermically. Histologic examination of the liver perfused hypothermically demonstrated hepatic arterial and/or portal venous congestion and mild-to-moderate hemorrhage in the portal triads. This study suggests that livers preserved for a prolonged period of time demonstrate a high hepatic arterial resistance shortly after revascularization, and that recipient hypothermia after revascularization may be a risk factor for the development of hepatic arterial thrombosis following liver transplantation.     

Improved Preservation of Warm Ischemic Livers by Hypothermic Machine Perfusion with Supplemented University of Wisconsin Solution

Hypothermic machine perfusion (HMP) has the potential to improve recovery and preservation of Donation after Cardiac Death (DCD) livers, including uncontrolled DCD livers. However, current perfusion solutions lack the needed substrates to improve energy recovery and minimize hepatic injury, if warm ischemic time (WIT) is extended. This proof-of-concept study tested the hypothesis that the University of Wisconsin (UW) solution supplemented with anaplerotic substrates, calcium chloride, thromboxane A₂ inhibitor, and antioxidants could improve HMP preservation and minimize reperfusion injury of warm ischemic livers. Preflushed rat livers subjected to 60 min WIT were preserved for 5 h with standard UW or supplemented UW (SUW) solution. Post preservation hepatic functions and viability were assessed during isolated perfusion with Krebs–Henseleit solution. Livers preserved with SUW showed significantly (p <. 001) improved recovery of tissue ATP levels (μ mol/g liver), 2.06 ± 0.10 (mean ± SE), as compared to the UW group, 0.70 ± 0.10, and the level was 80% of that of fresh control livers (2.60 ± 0.13). At the end of 1 h of rewarming, lactate dehydrogenase (U/L) in the perfusate was significantly (p <. 05) lower in the SUW group (429 ± 58) as compared to ischemia–reperfusion (IR) (781 ± 12) and the UW group (1151 ± 83). Bile production (μ g/min/g liver) was significantly (p <. 05) higher in the SUW group (280 ± 13) as compared to the IR (224 ± 24) and the UW group (114 ± 14). The tissue edema formation assessed by tissue wet–dry ratio was significantly (p <. 05) higher in UW group. Histology showed well-preserved hepatic structure in the SUW group. In conclusion, this study suggests that HMP with SUW solution has the potential to restore and preserve livers with extended WIT.