Single lung allotransplantation in pigs. A morphologic study of tissue preservation with modified Euro-Collins and fluorocarbon solutions

In the present study the functional and morphologic effects of two pulmoplegic solutions are evaluated. Single left-lung allotransplantation with ligation of the right pulmonary artery was performed in 15 piglets (13-20 kg). The lungs were preserved after donor prostaglandin E-1 treatment with single pulmonary artery flush with either modified Euro-Collins solution (mECS) (9 pigs) or oxygenated fluorocarbon emulsion (FC-43) (6 pigs) and transplanted after 6-hr storage in cold Physiosol solution. Tidal volumes of 15 ml/kg x fr (18) with 40% inspired oxygen were used for ventilation during reperfusion. Function of the transplanted lung was monitored for 4 hr postoperatively by determining pa CO2 and pa O2 levels from arterial samples and by noninvasive monitoring of end-tidal CO2 values and arterial oxygen saturations. Sequential morphologic changes in pulmonary artery flow surface and lung tissue were studied after 6-hr storage and 4-hr reperfusion, using light, scanning, and transmission electron microscopy (LM, SEM, TEM). There was no mortality. After transplantation the mECS group experienced significant hypoxia and hypercarbia and had low end-tidal CO2 values as signs of defective oxygenation and gas exchange, whereas the FC-43 group was normoxic and normoventilated without disturbed elimination of carbon dioxide. After storage and reperfusion, LM showed signs of increased vascular permeability and reperfusion damage--more evident in the mECS group compared with the FC-43 group--while the lymphoid cell population was more intensely activated in the latter group. Electron microscopy after storage showed good overall preservation of structures in both groups. After reperfusion preservation of pulmonary artery flow surface and lung tissue was estimated to be moderate in the mECS group, whereas it was good-to-moderate in the FC-43 group by SEM (NS). TEM of lung tissue, however, showed significantly better-preserved alveolar epithelial lining in the FC-43 group compared with the mECS group. In conclusion, oxygenated fluorocarbon (FC-43) pulmoplegia gave better functional and morphologic preservation of lung grafts compared with modified Euro-Collins solution.     

Liver adenine nucleotide metabolism during hypothermic anoxia and a recovery period in perfusion

Reduction of the level of ATP and of the total adenine nucleotide pool has been studied during cold storage of livers initially flushed with Ringer's lactate (R-L), Collins' solution (CO), modified Collins' solution (CMg), and a new hyperosmolar “intracellular” solution containing sucrose (KMgS).The reduction of ATP and nucleotides after 24 hr of anoxia is not influenced by the composition of the flushing solution. When the preserved livers are reperfused with oxygenated blood, the remaining adenine nucleotides are rapidly rephosphorylated, attesting to the persistence of mitochondrial functions irrespective of the solution used. In contrast, a synthesis of adenine nucleotides during the first hours following the anoxic period can only be obtained with the two solutions which have the highest osmolarity and magnesium sulfate content, the CMg and KMgS solutions.     

The isolated perfused porcine liver: assessment of viability during and after six hours of perfusion

Isolated liver perfusion was developed for the study of liver physiology and preservation. The recent development of new perfusion devices and appropriate liver preservation solutions prompted us to reconsider liver perfusion for the specific purpose of evaluating viability in terms of biochemical changes, paying special attention to modifications in the histological ultrastructure. Twenty-two isolated pig livers were perfused with autologous blood. Arterio-portal perfusions were carried out using an extracorporeal perfusion circuit with a hollow fibre membrane oxygenator. Four groups of pig livers were studied using three different liver flushing solutions [Ringer's lactate, ELOHES, and University of Wisconsin (UW)] and two different oxygenation modalities. Liver function tests and histological studies were done. Our results revealed that a high partial oxygen pressure (PO₂) level was deleterious to the ultrastructural elements of hepatocytes, in particular to the mitochondria. It was also associated with deficient metabolic performance, i. e., poor bile production and lack of aerobic metabolism. Normal blood gas values could be obtained with the use of air for liver oxygenation. Flushing of the liver with Ringer's lactate or a macromolecular solution such as ELOHES was associated with severe liver cell injuries, as reflected by a marked rise in liver enzymes and histological lesions. Satisfactory results were obtained when UW solution was used for liver harvesting. We conclude that an appropriate liver preservation solution, normal blood gas values, and normal physiological arterio-portal pressure and blood flow are essential for appropriate liver function with preservation of liver architecture and of hepatocyte ultrastructures. Total bilirubin in bile and Factor V are sensitive indicators of good liver function. Received: 24 January 1997 Received after revision: 18 April 1997 Accepted: 24 April 1997     

初始灌注液对离体低温保存大鼠肝脏的影响

目的 探讨缺血再灌注过程中初始灌注液对离体低温保存大鼠肝脏的影响。方法采用离体大鼠肝脏低温缺血保存再灌注模型90例,分别选择UW液、HC-A液和乳酸林格液作为不同的初始灌注液,观察大鼠肝脏在低温保存0、3、6、12、24 h后再灌注流出液中ALT、AST、LDH和ET的水平,同时比较3组之间肝脏细胞形态和细胞凋亡。结果 使用HC-A液作为初始灌注液的大鼠肝脏再灌注流出液中ALT、AST、LDH和ET水平较其他两组低(P<0.05),肝脏形态和细胞凋亡的发生3组差异无显著性。另外,上述指标均受低温保存时间的影响。结论 初始灌注液可影响离体低温保存大鼠肝脏的质量,细胞凋亡可能参与了肝脏的缺血再灌注损伤。     

Effect of cold aerobic perfusion on nonparenchymal cell viability of rat livers

Abstract We investigated the effect of oxygen supply on hepatic cellular viability during cold perfusion storage of rat livers- A perfluoro- N -methyldecahydroisoquinoline (FMIQ) emulsion is used as an oxygen carrier. The composition of the perfusate containing 20 w/v% FMIQ is essentially the same as the University of Wisconsin (UW) solution except for the exclusion of hydroxyethyl starch. Rat livers were perfused at 4°C for up to 24 h with either UW solution (group I, oxygenated; group II, unoxygenated) or FMIQ solution (group III, oxygenated; group IV, unoxygenated). After perfusion storage, the livers were reperfused with warm (37 °C) oxygenated or cold (4 °C) unoxygenated Krebs-Henseleit bicarbonate buffer, and nuclear trypan blue uptake was measured as the index of cell death. With warm oxygenated reperfusion, there remained less than 2% noviable parenchymal cells up to 24 h, regardless of perfusate or oxygenation. In UW-perfused livers, the proportion of nonviable nonprenchymal cells (NPC) increased progressively regardless of oxygenation, the values in groups I and II in the periportal field at 24 h being 39.9 ± 4.7% (mean ± SD) and 36.5 ± 4.2%, respectively. By contrast, in FMIQ-perfused livers, dye uptake by NPC was significantly reduced with oxygenation (16.9 ± 5.7% and 39.4%± 9.1% at 24 h in groups III and IV; P < 0.001). With cold unoxygenated reperfusion, livers in groups I, II, and IV showed a significant decrease of nonviable NPC, while those in group III showed no significant changes. These data indicate that oxygen supply during perfusion storage of the liver may ameliorate lethal injury to NPC precipitated during reperfusion.     

Pyridine nucleotide fluorometry in preserved porcine liver with fluorocarbon emulsion

Oxidation-reduction changes in pyridine nucleotide fluorescence were investigated in perfused and preserved porcine liver. A fluorocarbon emulsion (FC-43) was administered to the perfusate as an oxygen carrier to obtain full oxidation level by portal perfusion at a physiological low flow rate. A satisfactory reading was obtained by portal perfusion with EuroCollins' solution containing 10% v/v FC-43 at a rate of 0.5 ml/min/g liver. The amplitude (R x A) and the changing velocity (R x V) from full oxidation to full reduction were determined in the resultant trace curve. Both R x A and R x V decreased in inverse proportion to the duration of preservation period (3, 6, 12 hr). Adenine nucleotide content, hepatic energy charge level, and ketone body ratio in the tissue were simultaneously measured, and they also decreased proportionally to the duration of preservation. There were close positive correlations between R x A and total adenine nucleotide concentration (r = 0.841, P less than 0.01), between R x V and energy charge (r = 0.787, P less than 0.01), and between R x V and tissue ketone body ratio (r = 0.881, P less than 0.01). These results suggest that pyridine nucleotide fluorometry can accurately follow the cellular function of isolated porcine liver by administration of FC-43 in perfusate. This fluorometry may also have potential application in evaluating viability of a large organ like the human liver graft.     

The use of the University of Wisconsin (UW) and Euro-Collins (EC) solutions either alone or in a combined method

From June 1988 to October 1990, a total of 100 orthotopic liver transplantations (OLTs) in 91 patients were performed at the Hospital Clínic of Barcelona. Euro-Collins (EC) solution was used as the flush and storage solution in 29 livers, and the University of Wisconsin (UW) solution was used in 24. A combined method, consisting of flushing and harvesting the liver with UW solution through the portal vein and with EC solution through the aorta, was used in the remaining 47 livers. Livers harvested using such a combined method showed substantially better postoperative function in terms of AST, ALT, and prothrombin activity than those harvested in EC solution alone. Although AST and ALT values were lower in patoents whose livers were harvested using the combined method than with UW alone, differences were not significant. On the other hand, prothrombin activity was consistently better in the UW group. Bilirubin levels, platelet count, and bile output showed no difference among the three groups. We conclude that the combined use of UW and EC solutions for flushing and harvesting is not hazardous to human liver preservation and, in fact, may considerably reduce the amount of UW solution needed and, consequently, the costs.Preliminary results from this study were presented at the First International Congress of the Society for Organ Sharing in Rome in June 1991 and will also appear in Transplantation Proceedings.     

The superiority of cold oxygenated dilute blood cardioplegia

It has been clearly shown, both in a laboratory model and in humans, that oxygenation of crystalloid cardioplegic solutions markedly enhances myocardial preservation. The addition of a small volume of red cells to a crystalloid perfusate improves capillary perfusion. Based on these results, we have changed our cardioplegic solution from cold crystalloid to cold oxygenated dilute blood. In the present study we retrospectively evaluate the results of 400 operative procedures to determine whether the addition of oxygenation and a small volume of blood to the cardioplegic solution enhances myocardial protection in the clinical setting. Two hundred consecutive patients who underwent operation with cardioplegic arrest using a cold crystalloid cardioplegic solution (group 1) were compared with a subsequent 200 patients who underwent operation with cold oxygenated dilute blood cardioplegia (group 2). Patients in group 2, who received cold oxygenated dilute blood cardioplegia, had a significantly reduced need for postoperative intraaortic balloon pump counterpulsation and for atrioventricular pacing. Also, patients in group 2 had a lower incidence of perioperative myocardial infarction and had improved early outcome. None of the 200 patients in group 2 had electrocardiographic evidence of perioperative infarction. We conclude that cold oxygenated dilute blood cardioplegia provides better preservation than does a nonoxygenated crystalloid solution during elective ischemic arrest, because a cold crystalloid solution is able to deliver oxygen and the red cells are able to enhance capillary perfusion.     

Preservation of the myocardium by means of cold physiological solutions, as assessed by ventricular function, histochemistry and birefringence

The efficacy of myocardial preservation by means of cold, oxygenated Hartmann's, Bretschneider's, Eagle's Minimum Electrolyte Medium, and micro- or coarsely filtered Krebs' solution has been compared with that afforded by cold alone and by cross-perfusion from a healthy animal. The experimental preparation was an isolated heart free of inherent deterioration over the experimental period of 3 hr when crossperfused. Assessment was by isovolumic ventricular function tests and histological, histochemical and birefringence examination of drill biopsies.No means of cold, in vitro preservation of the heart permitted it to retain its mechanical performance as well as did normothermic cross-perfusion from a healthy animal, but all cold, oxygenated physiological solutions infused into the coronary arteries performed better than cold alone. Although few statistical differences were shown among the solutions, microfiltered modified Krebs' solution and modified Eagle's Minimum Electrolyte Medium were consistently more effective.Histochemical and birefringence behavior of the myocardium was disappointing in predicting mechanical performance of the myocardium after cold preservation, presumably because cold permits histochemical appearances to be preserved when function is not. Nevertheless, the groups with the poorest residual function showed the most histological damage.     

Brief O2 uploading during continuous hypothermic machine perfusion is simple yet effective oxygenation method to improve initial kidney function in a porcine autotransplant model

With oxygenation proposed as a resuscitative measure during hypothermic models of preservation, the aim of this study was to evaluate the optimal start time of oxygenation during continuous hypothermic machine perfusion (HMP). In this porcine ischemia‐reperfusion autotransplant model, the left kidney of a ±40 kg pig was exposed to 30 minutes of warm ischemia prior to 22 hours of HMP and autotransplantation. Kidneys were randomized to receive 2 hours of oxygenation during HMP either at the start (n = 6), or end of the perfusion (n = 5) and outcomes were compared to standard, nonoxygenated HMP (n = 6) and continuous oxygenated HMP (n = 8). The brief initial and continuous oxygenated HMP groups were associated with superior graft recovery compared to either standard, nonoxygenated HMP or kidneys oxygenated at the end of HMP. This correlated with significant metabolic differences in perfusate (eg, lactate, succinate, flavin mononucleotide) and tissues (eg, succinate, adenosine triphosphate, hypoxia‐inducible factor‐1α, nuclear factor erythroid 2‐related factor 2) suggesting superior mitochondrial preservation with initial oxygenation. Brief initial O₂ uploading during HMP at procurement site might be an easy and effective preservation strategy to maintain aerobic metabolism, protect mitochondria, and achieve an improved early renal graft function compared with standard HMP or oxygen supply shortly at the end of HMP preservation.     

The significance of preserving the energy status and microcirculation in liver grafts from non-heart-beating donor

To complete a successful liver transplantation (LTx) from non-heart-beating donors (NHBD), it is necessary to both improve the energy status in liver grafts and to reduce the exposure to free radicals. This study investigated the effects of short perfusion with oxygenated buffer on the grafts prior to cold preservation. In addition, the effects of the antioxidant, biliverdin, for reduction of free radicals was investigated. Male Wistar rats were used. Livers were retrieved, preserved in UW solution, and perfused for 60 min with oxygenated Krebs-Henseleit solution. Rats were allocated to six groups as follows (n=5): (i) control group-no warm ischemia (WI) and cold preservation, (ii) HBD group--no WI with cold preservation for 6 h; (iii) NHBD group--with 30 min of WI and cold preservation, (iv) NM group--with WI including nafamostat mesilate infusion before cardiac arrest and cold preservation; (v) PRE group--with WI, 30-min pre-cold preservation perfusion with oxygenated buffer after cardiac arrest, and cold preservation, (vi) BV group-with the same treatment as the PRE group plus the addition of biliverdin to the pre-cold preservation perfusion. The portal flow volume, bile production, AST, and TNF-alpha in perfusate, energy charge (EC), and ATP level in the tissue, and histological findings were investigated. The portal flow volume in the NM, PRE, and BV groups were higher than in the NHBD group. The bile production in the PRE and BV groups were also higher than in the NHBD group. The EC and ATP level of the BV group after reperfusion were higher than those of the NHBD group. Pre-cold preservation perfusion and addition of biliverdin to perfusate improved viability of grafts from NHBD. The results indicate that the preservation of the energy status and microcirculation of the graft is important for successful LTx from NHBD.     

Evaluation of a preservation solution containing fructose-1,6-diphosphate and mannitol using the isolated perfused rat kidney. Comparison with Euro-Collins and University of Wisconsin solutions

The renal preservation ability of a flushing solution (F-M)with fructose-1,6-diphosphate (1 g/dl) and mannitol (2 g/dl)during cold ischaemia was studied with the isolated perfusedrat kidney model and compared with the Euro-Collins (EC) andUniversity of Wisconsin (UW) solutions. Kidneys were storedin hypothermia for 4 and 18 h after initial flushing with thesolution being tested, and then reperfused at 37°C in anisolated perfusion circuit for 90 min with a Krebs-Henseleitsolution containing 4.5% albumin. Forty-four kidneys were studied and divided in a control groupand six study groups according to the cold ischaemia time andflushing solution used. Renal functional parameters of plasmaflow rate (PFR), renal vascular resistance (RVR), urine flowrate (UFR) glomerular filtration rate (GFR), fractional (FRNa)and net (TNa) sodium reabsortion were assessed during reperfusion.Conventional histology and malon-dialdehyde tissue levels (MDA)were also evaluated. Our results show that PFR, RVR, and UFR were similar in allstudy groups. After 4 and 18 h of cold ischaemia, GFR, FRNaand TNa were better, and conventional histology worse in F-Mthan in EC flushed kidneys. After 4 and 18 h of cold ischaemia,GFR, FRNa and TNa, in fact, were not different between F-M andUW flushed kidneys. After 4 h of cold ischaemia, conventionalhistology was similar in F-M and UW flushed kidneys. Nevertheless,after 18 h of cold ischaemia, UW flushed kidneys showed worsehistological parameters than F-M flushed kidneys. After 4 hof cold ischaemia, MDA was similar in kidneys flushed with thethree solutions. After 18 h of cold ischaemia MDA was higherin EC than in F-M or UW flushed kidneys. In summary, our newly developed cold storage solution showspromising results in renal preservation and its ability to preserveis at least as good as UW solution assessed in the isolatedperfused rat kidney.     

Extended preservation of non-heart-beating donor livers with normothermic machine perfusion

BACKGROUND: Non-heart-beating donor (NHBD) livers represent an important organ pool, but are seldom utilized clinically and require rapid retrieval and implantation. Experimental work with oxygenated perfusion during preservation has shown promising results by recovering function in these livers. This study compared sanguinous perfusion with cold storage for extended preservation of the NHBD liver in a porcine model. METHODS: Porcine livers were subjected to 60 min of in vivo total warm ischaemia before flushing, after which they were preserved by one of two methods: group 1 (n = 4), University of Wisconsin (UW) solution by standard cold storage for 24 h; group 2 (n = 4), oxygenated autologous blood perfusion on an extracorporeal circuit for 24 h. All livers were subsequently tested on the circuit during a 24-h reperfusion phase. RESULTS: Livers in group 1 showed no evidence of viability during the reperfusion phase with no bile production or glucose utilization; they also displayed massive necrosis. Livers in group 2 demonstrated recovery of function by synthetic function, substrate utilization and perfusion haemodynamics; these livers displayed less cellular injury by hepatocellular enzymes. All differences in parameters between the two groups were statistically significant (P < 0.05). These findings were supported by histological examination. CONCLUSION: Warm ischaemia for 1 h and simple cold storage (UW solution) for 24 h renders the liver non-viable. Oxygenated, sanguinous perfusion as a method of preservation recovers liver function to a viable level after 24 h of preservation.     

Reduced oxidative stress during acellular reperfusion of the rat liver after hypothermic oscillating perfusion.

BACKGROUND: ATP resynthesis during reperfusion after liver preservation has been shown to be well correlated with the function of transplanted grafts. Nevertheless, the advantages of a cellular energy charge loading during the preservation period are yet not fully understood. This study evaluates the effects of different nucleotide levels at the end of preservation on metabolic changes and oxidative stress during reperfusion. METHODS: Two experimental groups were chosen reflecting different energy charge states after preservation: static cold storage for 10 hr and hypothermic oxygenated oscillating perfusion for 10 hr. In both experimental groups, normothermic ex vivo acellular reperfusion over 40 min was performed. A third group consisted of nonpreserved livers similarly reperfused for 40 min. Superoxide formation was detected by the superoxide dismutase inhibitable reduction of ferricytochrome c added to the normothermic perfusate. RESULTS: Superoxide formation and lipid peroxidation malondialdehyde were significantly lower during reperfusion after the energy charge loading before reperfusion by the hypothermic oscillating perfusion technique. However, oxygen radical formation, liver cell injury (lactate dehydrogenase [LDH] release), and TNFalpha release were significantly higher in energy charge-depleted groups (nonpreserved and cold stored livers). CONCLUSIONS: Hypothermic oscillating oxygenated perfusion led to the elevated energy charge during preservation and led to reduced oxygen radical formation as well as less lipid peroxidation during reperfusion, in contrast to cold stored livers and nonpreserved livers. This suggests a correlation between the energy charge before reperfusion and oxygen radical formation as well as liver injury at reperfusion.     

Rat liver preservation

The mechanisms by which cold preservation solutions exert their protective effects are only partially understood. The consequences of mixing different solutions, with presumably different modes of action, may be additive and beneficial or may be deleterious. It is commonplace in clinical liver preservation to use Ringer's lactate (RL), Eurocollins (EC), and University of Wisconsin (UW) solution in sequence for washout of blood, precooling, and cold storage of the organ. In this study, 114 Sprague Dawley rats received orthotopic liver transplants that were flushed in various sequences with RL, EC, and UW solutions. One-week animal survival served as the criterion of preservation success. The results demonstrated that liver preservation with UW solution alone is significantly superior (P<0.01) to any combination of RL, EC, and UW solutions and may explain some of the instances of primary nonfunction in clinical liver transplantation.     

Liver transplantation from non–heart beating donors in rats: Influence of viscosity and temperature of initial flushing solutions on graft function

BACKGROUND: We evaluated the effect of warm (37 degrees C) versus cold (4 degrees C) solutions as the initial flush for liver preservation from non-heart beating donors in rats. METHODS: An initial flush was performed just before donor hepatectomy with cold or warm University of Wisconsin solution (UW), UW without hydroxyethyl starch, sodium lactobionate sucrose solution, or lactated Ringer's solution as the control group. A separate group also used as control received no initial flushing. Liver transplantation was performed, and the graft function was determined by survival and assessment of enzyme release. The viscosity of each solution and the vascular resistance of the graft were measured. RESULTS: The 7-day survival rate was 83% and 100% in the warm and cold sodium lactobionate sucrose solution groups and 60% and 50% in the warm and cold lactated Ringer's solution groups, respectively. In the no-initial-flush group, rats did not survive. The 7-day survival rate was 67% and 0% in the warm and cold UW groups, respectively. Eliminating the hydroxyethyl starch from the cold UW improved the survival to 67%. Serum alanine aminotransferase levels 1 day after transplantation in the no-initial-flush and the cold UW groups were significantly higher than those of the remaining groups. At 4 degrees C the viscosity was higher in the UW (86.2 cp) compared to hydroxyethyl starch-free UW solution (30.9 cp), lactated Ringer's solution (24.5 cp), and sodium lactobionate sucrose solution (32.7 cp). The viscosity of UW at 37 degrees C was 34.7 cp. Vascular resistance correlated well with the viscosity. Livers flushed with solutions with a low viscosity showed lower vascular resistance than those flushed with cold UW and led to better survival. CONCLUSIONS: These data suggest that the viscosity of the initial flushing solution may play an important role in determining the outcome of organ procurement from non- heart beating donors. (Liver Transpl Surg 1997 Jan;3(1):39-45)     

供肝保存液的演变和革新

器官保存液能够改善移植物冷缺血损伤和维持移植物良好的功能。目前,如何减少供肝在冷缺血期间引起的一系列损伤,改善和提高移植物的保存质量,是目前该领域研究的热点和难点。现阶段,临床上的保存液仍未达到理想的保存效果,尤其是对于边缘供器官的保护作用不尽如人意。在当今供者极度匮乏的情况下,为了改善移植物免受冷缺血损伤,其关键要素仍然是寻求最佳的供肝保存方案。本文总结了供肝在冷缺血期间的损伤机制,保存液的分类及供肝保存液的演变历程,探讨了供肝保存液的发展方向及面临的困境,为供肝保存液的研发提供新思路和参考。     

Effect of normothermic perfusion using fructose-1,6-bisphosphate for maintenance of liver function during in situ extended hepatectomy by the total hepatic vascular exclusion technique

BACKGROUND: Recently, hepatic surgery has made remarkable progress, and it is important to use appropriate liver perfusion. We evaluated the effect of normothermic liver perfusion with the addition of fructose-1, 6-bisphosphate (FBP) and oxygenation to maintain liver parenchymal, non-parenchymal, and Kupffer cell function. MATERIALS AND METHODS: The rats were divided into five groups according to the perfusate and continuous perfusion was performed: Control group = 4 degrees C lactate Ringer with 10% glucose (LRG) solution; normothermic group = 25 degrees C LRG solution; normothermic oxygenated group = 25 degrees C oxygenated LRG solution; normothermic FBP group = 25 degrees C LRG solution with addition of 10 mmol/L FBP; normothermic oxygenated FBP group = 25 degrees C oxygenated LRG solution with addition of 10 mmol/L FBP. Parameters under evaluation were oxygen consumption, liver energy level (adenosine triphosphate, total adenine nucleotide), glutathione, lipid peroxide, hyaluronic acid uptake ratio, apoptosis, and histomorphology. Moreover, we studied the effect of FBP and normothermia on Kupffer cells activation in vitro. RESULTS: Liver energy level was lower in the normothermic group than the control group. But, it was improved by oxidation or addition of FBP, and it was satisfactorily maintained up to 120 min in the group with normothermic oxygenated FBP. Hyaluronic acid uptake was maintained highly at all times as measured in normothermic oxygenated FBP group. The uptake of lipopolysaccharide was significantly higher as a result of adding FBP, compared with that in the control group and the normothermic group. Moreover, the apoptotic index in the liver was decreased in normothermic FBP group compared to control group. CONCLUSIONS: The normothermic liver perfusion under additional FBP and oxygenation protects both parenchymal and non-parenchymal cells from reperfusion injury.     

Comparison of University of Wisconsin (UW) and Eurocollins (EC) preservation solutions in a rat liver transplant model

The Eurocollins (EC) and University of Wisconsin (UW) preservation solutions were compared in a rat liver transplant model. After hepatectomy, 48 rat livers were flushed with either EC or UW preservation solution and were randomly assigned to 1, 12, 24, and 30 h of preservation at 4°C, resulting in eight groups each containing six livers. Following preservation, orthotopic liver transplantation with reconstruction of the hepatic artery was performed. The efficacy of the preservation solution was assessed at 48 h post-transplantation by survival histological features and aspartate transaminase assay (AST) values. None of the rats survived 30 h of liver preservation with EC whereas five out of six rats did with UW preservation. After 24 h of liver preservation, three of the six rats in the EC group survived, compared to all six rats in the UW group. Histological evidence of severe ischemia was found in both groups in all but one survivor (UW, 24 h). After 12 h of EC preservation, one rat died within 48 h and severe ischemic changes were found in the remaining five rats. Among the rats with 12 h of UW preservation, only two out of six showed ischemic changes, and all six rats survived beyond 48 h. Without preservation (1 h), ischemic damage was found in two out of six rats in each group and all rats survived. The median AST values were higher in the EC groups than in the UW groups; the difference became significant after 12-h preservation (EC 900 IU/l versus UW 465 IU/l) and 24-h preservation (EC 5220 IU/l versus UW 631 IU/l). However, the median AST value in the five surviving rats whose livers had been preserved for 30 h in UW climbed to 1880 (950–2240) IU/l.. We conclude that UW solution provides better long-term preservation than EC solution. However, even with UW solution, the observed mortality, the severity of ischemic changes, and the pronounced increase in the median AST value cast doubt upon the safety of liver preservation beyond 24 h.