Preventative effect of PGE1 for postoperative liver damage

The efficacy of a low dose of PGE₁-use on the postoperative liver damage was evaluated. PGE₁ was infused in with the mean rate of 0.026µg·kg^–1·min^–1 during surgical procedure to 93 patients under GO-enflurane anesthesia (the PG). Serum GOT, GPT and total bilirubin (TBIL) values measured before, at the end of (End) and 3 days (3d) after the operation were compared to those obtained from 43 patients without PGE₁ administration (the control).This dose of PGE₁ did not change blood pressure and heart rate, but slightly decreased Pa_{O 2}. In patients with preoperative normal values of GOT, GPT and TBIL, increases in GOT, GPT and TBIL observed at End in the PG were significantly lower than those in the control (31.9 vs 72.2IU, 25.9 vs 61.9IU, 0.68 vs 0.83mg·dl^–1, respectively). GOT, GPT and TBIL at 3d significantly increased in both groups, and these levels were identical between the two groups. In patients with preoperative abnormal values, only GOT at End increased in both groups, while no significant difference between the PG and the control group was noted. GOT at 3d and GPT at End and 3d did not significantly changed in either group. These results suggest that the low dose of PGE₁ administered during an operation prevents the development of postoperative liver damage, but does not treat the damaged hepatic cells.(Iwatsuki N, Yasuda A, Tokutomi S, et al.: Preventative effects of PGE₁ for postoperative liver damage. J Anesth 6: 131–137, 1992)     

Microcirculatory disturbances and leucocyte adherence in transplanted livers after cold storage in Euro-Collins,UW and HTK solutions

Integrity of the hepatic microcirculation and maintenance of endothelial cell viability are critical components in preventing primary non-function after liver transplantation. Therefore, hepatic microcirculation and leucocyte-endothelial interaction were studied in rat livers stored for 1 h in Euro-Collins (EC), University of Wisconsin (UW), and histidine-tryptophan-ketoglutarate (HTK) solutions and subsequently transplanted. One hour after transplantation surgery, the livers were exposed under an intravital fluorescence microscope. After injection of the leucocyte marker acridine orange (1 mol/kg), six pericentral fields were observed for 30 s and experiments were recorded continuously. The percentage of perfused sinusoids was reduced in the livers in the EC group (82.9%) in contrast to the UW (93.2%) and HTK groups (91.0%). Livers in the EC group showed a reduction in the diameters of pericentral sinusoids (7.3±0.2 m; mean±SEM) compared with the UW group (9.5±0.2 m; P<0.05) and HTK group (10.2±0.8 m; P<0.05), indicating substantial cell swelling in livers stored in EC solution. Permanent adherence of leucocytes was most frequently observed in the EC group (33.5±1%), while this phenomenon was less pronounced in the UW group (14.5+1.1%; P<0.05) and HTK group (16.3±0.7%; P<0.05). Conversely, temporary adherence of leucocytes was reduced in the EC group (19.7+1.3%) compared with the UW group (30.5+2.1%) and the HTK group (34.4+0.8%). Microcirculatory failure and cell swelling in the EC group might be due to the lack of osmotic substances or oxygen radical scavengers included in UW (allopurinol, glutathione) and HTK (mannitol) solutions. In conclusion, cold storage of livers in UW and HTK solutions results in better preservation of the microcirculation and prevention of adhesion of leucocytes after transplantation compared with the EC solution.     

The effects of intraportal prostaglandin E1 administration on hepatic warm ischemia and reperfusion injury in dogs

To determine the route of prostaglandin E₁ (PGE₁) administration which would have the greatest protective effect against hepatic warm ischemia, two experiments were performed using dogs. The pharmacokinetics of PGE₁ were investigated in a preliminary study, after which, the effects of PGE₁ in a 90-min warm ischemic liver model were examined. The dogs were divided into three groups of ten, according to the treatment given: group A was an untreated control group, group B received PGE₁ intravenously, and group C received PGE₁ intraportally. The PGE₁ was infused continuously at a rate of 0.02 g/kg/min before and after ischemia. All the dogs in groups A and B died within 24 h of induced ischemia. Whereas, six of the ten dogs in group C survived for over 3 days. The arterial ketone body ratio was not maintained in groups A and B, but it was in group C. Furthermore, in group C the serum lipid peroxide level, which reflects hepatocellular membrane damage, was maintained at a lower level than that in the other groups after ischemia. Electron microscopy revealed sinusoid destruction and changes in both the plasma membrane and parenchymal cell mitochondria in groups A and B, while in group C these structures were well preserved. These findings confirmed that intraportally administered PGE₁ improved the hepatic microcirculation and stabilized the hepatocellular membranes. Our results indicate that intraportal administration of PGE₁ has a greater protective effect than intravenous administration against warm ischemic liver injury.     

Enhanced hepatic portal blood flow induced by prostaglandin E1 following liver transplantation in pigs

Portal venous blood flow (PVF), hepatic arterial blood flow (HAF), and systemic arterial pressure (SAP) were examined after prostaglandin E₁ (PGE₁) was injected into the vena cava superior (VCS) of liver-transplanted pigs. The injection of PGE₁ at 0.2 g/kg/min for 2 min on the day of transplantation and 3 days later produced an increase in PVF without causing any change in HAF or SAP, the response in PVF being dose-dependent. However, no reliable change in PVF, HAF, or SAP was seen when the same dose of PGE₁ was administered 7 days after transplantation. Furthermore, no significant difference was noted among the values for PVF and total hepatic blood flow (THF) during the experimented days, although the HAF value had increased markedly 3 days after transplantation. These findings suggest that PGE₁ is effective in increasing PVF in the liver transplanted condition; however, the hepatic circulatory improvement attributed to this agent would be limited to the first few days following transplantation.     

Comparison of histidine-tryptophan-ketoglutarate (HTK) solution versus University of Wisconsin (UW) solution for organ preservation in human liver transplantation

Over a 30-month period, 60 patients (30 in each group) suffering from end-stage liver disease or primary hepatic malignancy and scheduled for liver transplantation were enrolled in a prospective, randomized study to compare two methods of liver preservation: histidinetryptophan-ketoglutarate (HTK) solution versus University of Wisconsin (UW) solution. Entry criteria for both groups were: age (18–65 years), elective surgery (transplantable or urgent category of the recipients), first transplantations and harvesting procedure performed by the same team. The parameters under investigation were the clinical and laboratory data preand post-transplantation, as well as follow-up data such as complications and survival. There were no significant differences in the two groups as far as the evaluation criteria were concerned, even when cold ischemia time was more than 15h (n=7). A slight, yet not significant, increase in late complications of the biliary anastomoses could be seen in the UW group. Hepatocellular injury (SGOT, SGPT, GLDH, lactate) appeared to be more marked in the HTK group. These results suggest that both HTK and UW solutions are appropriate for clinical use in liver transplantation, even if cold ischemia time is more than 15h.     

Donor pretreatment with gadolinium chloride improves early graft function and survival after porcine liver transplantation

Kupffer cell depletion by gadolinium chloride (GdCl₃) in rat livers has previously been proven to minimize hepatic ischemia/reperfusion injury after experimental liver transplantation (LTX). In the current study, we evaluated the effects of donor pretreatment with GdCl₃ on hepatic ischemia/reperfusion injury, macro- and microcirculation, and endotoxin clearance of the liver in a porcine model of experimental LTX. Two groups of 12 pigs were treated either with intravenous NaCl (0.9%; control) or GdCl₃ (20 mg/kg). Twenty-four hours after pretreatment, hepatic macrocirculation was quantified by Doppler flowmetry and liver parenchymous microcirculation by implanted thermodiffusion electrodes. The liver grafts were transplanted after 4–6 h of cold ischemia in University of Wisconsin (UW) solution. At 1 and 24 h after LTX, the perfusion values were re-evaluated and histology, biochemical (aspartate aminotransferase, AST) and functional parameters (partial thromboplastin time, prothrombin time, and bilirubin) were analyzed. Furthermore, endotoxin clearance of the liver was evaluated at all time points. In GdCl₃-treated animals 80% of the Kupffer cells were destroyed, and 24 h after LTX ischemia/reperfusion injury in treated grafts was significantly lower in comparison to controls, as shown by histology, AST levels (741±490 U/l in controls vs 379±159 U/l in treated grafts, P<0.05), survival (67% vs 92%), and enhanced macro- (total transhepatic blood flow [THBF]=112±22 ml/min per 100 g in controls vs 157±45 ml/min per 100 g in treated grafts, P0.05) and microcirculation (thermodiffusion [TD]=73±9 ml/min per 100 g in controls vs 90±16 ml/min per 100 g in treated grafts, P0.05). Despite destruction of the macrophage system in the liver, the transhepatic endotoxin gradient of treated livers was enhanced before and 1 h after transplantation (58% in controls vs 85% in treated grafts, P<0.05). Destruction of Kupffer cells of donors by pretreatment with GdCl₃ in pigs is effective in preventing liver graft dys- and nonfunction after LTX. Pretreatment with GdCl₃ does not diminish but increase hepatic endotoxin clearance.     

Beneficial effects of administering intraportal prostaglandin E1 postoperatively to hepatectomy patients with massive intraoperative blood loss

Massive intraoperative blood loss is a major cause of complications following hepatectomy. To evaluate the efficacy of intraportal prostaglandin E₁ (PGE₁) for preventing liver deterioration in hepatectomy patients with an intraoperative blood loss of over 2000 ml, a retrospective analysis was conducted on 10 patients given intraportal PGE₁ (portal group), 6 given intravenous PGE₁ (venous group), and 10 given no treatment (control group). PGE₁ was infused at 250 or 500 g/day in the portal group and at 720 g/day in the venous group, and continued for 3 days postoperatively. Alanine aminotransferase (ALT) and total bilirubin (T.Bil) were measured on postoperative days (PODs) 1, 3, 5, and 7. ALT was lower in the portal group than in the other two groups on each POD, and significantly lower than in the control group on POD 3 (P<0.05). T.Bil was significantly lower in the portal group than in the control group on PODs 5 and 7 (P<0.05). T.Bil on POD 7 was under 1.5 mg/dl in 1 (10.0%), 6 (60.0%), and 2 (33.3%) of the control, portal, and venous group patients, respectively, with a significant difference between the control and portal groups (P<0.05). These results confirmed that intraportal PGE₁ was beneficial for improving hepatic function and preventing cholestasis in patients with a blood loss of over 2000 ml at risk of developing postoperative liver deterioration.     

Effect of prostaglandin E1 on arterial ketone body ratio in hepatectomy

We evaluated the effect of prostaglandin E₁ (PGE₁) administration during hepatectomy on arterial ketone body ratio (AKBR), which is an indicator of liver function, and on other liver functions in the postoperative period. Eighteen patients were divided into two groups: Continuous intravenous administration of PGE₁ (0.02 μg·kg⁻¹·h⁻¹) was started immediately before hepatic resection and ceased at the end of operation in nine patients (PGE₁ group); the other nine did not receive PGE₁ (control group). After hepatic resection, a significant increase in AKBR was observed in the PGE₁ group. However, no change was observed in the control group. In the PGE₁ group, total bilirubin and SGOT recovered more rapidly to the preoperative level than in the control group. These findings suggested that PGE₁ might have a protective effect on the liver.     

The effect of Intraportal PGE1 on Warm Ischemic Liver Damage

To determine the most effective route of administering prostaglandin E₁ (PGE₁) to inhibit warm ischemic liver damage, 90-min warm ischemia was established in a canine model. The dogs were divided into three groups according to the treatment given. Thus, group A (n = 10) was the control group which received no treatment, group B (n = 7) was administered PGE₁ intravenously, and group C (n = 7) was administered PGE₁ intraportally. PGE₁ was continuously administered before and after the ischemia at a rate of 0.02⦰/min. The branched-chain amino acid to aromatic amino acid ratio in the hepatic vein, and the arterial ketone body ratio of acetoacetic acid to -hydroxybutyric acid, were examined to observe the metabolism of each amino acid and the oxidation-reduction ability of hepatocytes. Both ratios were maintained only in the group C dogs, three of which survived for over 3 days, whereas in groups A and B, all the dogs died within 24h. The results of this study imply that the intraportal administration of PGEI was more effective against warm ischemic liver damage than the intravenous administration of PGE₁.     

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.     

An underlying mechanism for improved liver preservation with a combined histidine-lactobionate-raffinose flush solution

In previous experimental liver transplant studies, it was possible to extend cold ischaemic time (CIT) by using a flush/storage solution combining histidine, lactobionate and raffinose (HLR). In this study, energy metabolism, glycolytic substrate (glucose) and anaerobic end-product (lactate) were examined in rat liver over 24 h of cold storage to determine the mechanism of action of the HLR solution. In livers subjected to simple flush and storage with the HLR solution. levels of ATP and ADP were considerably higher than livers stored with modified UW throughout 24 h of storage; at 4 h of storage, ATP and ADP levels were 1.1 and 3.1 mol/g for HLR solution versus 0.18 and 0.81 mol/g for UW solution. Total adenylate contents (TA=ATP+ADP+AMP) also remained 1–2 mol/g higher in HLR-treated livers than those preserved in UW; TA values ranged from 3.8 to 5.7 mol/g. Glucose increased to 20–35 mol/g by 10–24 h of storage (similar to the UW group). Lactate rose to almost twice that in livers stored in UW; total lactate accumulation was approximately 10.0 mol/g. This study demonstrated that the combined HLR solution is able to prolong the maximum safe CIT by increasing anaerobic metabolism and consequently preserving liver energetics. The second part of the experiment examined the effect of continuous perfusion (with/without O₂) over the 1st h of cold ischaemia. Under current methods of liver flushing and excision, the 1st h of cold storage may be the critical time of metabolic adjustment since most of the pH and ATP changes occur during this period. Therefore, we tested the hypothesis that the combination of a simple flush with an additional brief 1-h perfusion period prior to storage would enhance the maintenance of hepatic energetics. There was no beneficial effect of 1 h of perfusion without O₂ compared to simple HLR flush and storage. However, perfusion with O₂ resulted in prolonged maintenance of high energy adenylates and total adenylates; at 10 h of storage ATP was 1.0, ADP 3.3, and TA 5.7 mol/g. However, any improvement in ultimate viability following long-term storage of the livers in these two groups needs to be tested in an animal transplant model.     

Improved microcirculation by low‐viscosity histidine– tryptophan–ketoglutarate graft flush and subsequent cold storage in University of Wisconsin solution: results of an orthotopic rat liver transplantation model

As previously shown in a model of isolated rat liver perfusion, the combined use of an initial graft flush with low‐viscosity histidine–tryptophan–ketoglutarate (HTK) solution followed by cold storage in University of Wisconsin (UW) solution markedly improved the preservation during an extended cold storage period. In this study, we aimed to transfer our results into an in vivo model of orthotopic rat liver transplantation, and to elucidate the potential mechanism of the improved preservation by focusing on the hepatic microcirculation. Livers were harvested from male Wistar rats. Aortic perfusion with a pressure of 100 cm H₂O was performed with either UW (group UW) or HTK (groups UW and HTK_UW), followed by additional back‐table perfusion with UW (group HTK_UW). After 20‐h cold storage at 4 °C, livers were orthotopically transplanted with reconstructing the hepatic artery. As measured by bile flow and liver enzymes, HTK flush followed by UW storage was superior compared to single use of either UW or HTK solution. The hepatic microcirculation was significantly improved, as shown by the increased percentage of reperfused sinusoids and reduced sinusoidal leucostasis. HTK and UW effectively reduce ischaemia‐reperfusion injury after liver transplantation. By combining the comparative advantages of both solutions, a cumulative effect resulting in an improved preservation was shown. Thus, this mechanism improves microcirculatory reperfusion.     

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.     

Liberation of vasoactive substances and its prevention with thromboxane A2 synthase inhibitor in pig liver transplantation

There are multiple causes of liver graft nonfunction in the early post-transplant period. Since a severe microcirculatory disturbance based on ischemia-reperfusion liver injury is considered to be the main underlying pathophysiology, it is suspected that various vasoactive substances are liberated after reperfusion of the graft. In order to investigate this matter, we conducted an experimental study with pig liver allotransplantation. Two groups of animals received donor grafts with or without thromboxane synthase inhibitor (sodium ozagrel), 1.25 mg/kg body weight intravenously, given at the time of liver harvesting. All of the recipient animals in the treatment group (n=10) survived longer than 7 days whereas three of ten animals in the control group died within 7 days. Serum lactate dehydrogenase (LDH) in the recipient serum at 1 h after reperfusion was significantly lower in the treatment group (915.1±167.3 U/l) than in the control group (1264.4±134.7 U/l). Serum thromboxane B₂ (2261.7±1055.7 pg/ml) and endothelin-1 (6.3±2.2 pg/ml) after reperfusion in the treatment group were significantly lower than those in the control group (4220.0±1711.0 pg/ml and 11.2±3.1 pg/ml, respectively). Although serum angiotensin II after reperfusion tended to be lower in the treatment group than in the controls serum renin activity was less than 3 ng/ml in both groups of animals. There were no differences in the plasma endotoxin levels between the two groups. We conclude that the administration of sodium ozagrel to the donor animals provided better graft function in recipients than no such treatment. We speculate that the inhibition of thromboxane A₂ production suppresses the liberation of other vasoconstrictive substances, preventing microcirculatory disturbance and, thereby, contributing to improved graft function after liver transplantation.     

A comparison of histadine lactobionate solution with University of Wisconsin solution for rat liver and heart preservation

We developed a new solution mainly composed of Na-lactobionate and histidine (HL) and compared the effectiveness of this solution with that of University of Wisconsin (UW) solution using orthotopic liver and heterotopic heart transplantation in rats. The new solution has a higher sodium content and a lower potassium content (Na, 90 mEq/l; K, 45 mEq/l) than UW. Hydroxyethyl starch, adenosine, dexamethasone and insulin are not included. Buffering capacity is increased by adding histidine (90 mm/l) together with KH₂PO₄ (20 mm/l). Rat liver was perserved in either UW or HL solution hypothermically for 24 h and then transplanted orthotopically into the recipient rat. The heart was preserved in either solution for 18 h and transplanted heterotopically into the recipient rat. The 1-week survival rate for rats receiving livers preserved in UW for 24 h at 4°C was 29% (5/17). In contrast, the new solution (HL) gave a 78% (11/14) survival rate (P < 0.01). The 1-week heart graft survival rate, using UW solution was 50% (3/6), following 18-h cold preservation, whereas all hearts (7/7) continued to beat for over a week using new HL solution (P < 0.05). These results demonstrated that the new HL solution, with a substantial buffering capacity, was superior to UW solution in rat liver and heart preservation.     

The protective effect of thromboxane A2 synthetase inhibitor against ischemic liver injury

To evaluate the role of thromboxane A₂ (TXA₂) in ischemic liver injury, the serum changes in thromboxane B₂ (TXB₂) and 6-keto-prostaglandin F₁ alpha (6-K-PGF₁) following warm ischemia of the total canine liver were examined, and the protective effect of a TXA₂ synthetase inhibitor was assessed. Total liver ischemia was performed for 60 min on two groups of dogs: a control group, in which ischemia alone was performed, and an OKY-046 group, which received a TXA₂ synthetase inhibitor. A temporary active portacaval shunt was used to eliminate the effects of splanchnic venous stasis during clamping of the hepatic pedicle. Postoperative changes in liver function, assessed by the transaminase enzyme levels, and in prostaglandins were recorded and the histologic liver findings of both groups 1 week after ischemia were compared. The levels of 6-K-PGF₁ increased after reperfusion in both groups, while those of TXB₂ increased in the control group but maintained low levels in the OKY-046 group. Liver function was better and histologic changes less marked in the OKY-046 group than in the control group, suggesting the important role of TXA₂ in ischemic liver injury and the usefulness of a TXA₂ synthetase inhibitor for protecting the liver against ischemic injury.     

In vitro evaluation of donor liver preservation fluids on human hepatocyte function

Successful liver transplantation depends on adequate preservation of cellular function. We therefore tested the effects of two currently used liver preservation fluids, Euro-Collins (EC) solution and University of Wisconsin (UW) solution, on the viability and some functional activities of hepatocytes isolated from human livers. Cells in primary culture were maintained under hypoxic (95% N₂/5% CO₂) and hypothermic (4°C) conditions for 24 h, either in EC or UW solution. This treatment did not result in significant hepatocyte damage, as judged by phase contrast microscopy, intracellular LDH release, and the MTT mitochondrial test. However, neutral red uptake indicated that lysosomal functions were slightly affected (35% decrease) when compared to control conditions. At the end of the hypoxia/hypothermia period, hepatocyte monolayers were incubated at 37°C under normoxic conditions for 24 h, in order to simulate the reperfusion of a transplanted liver. Three drugs-midazolam, diazepam, zidovudine-were used as diagnostic substrates to check the metabolic abilities of human hepatocytes replaced in normal conditions. Both phase I (hydroxylation, demethylation) and phase II (glucuronidation) metabolic reactions were affected by the hypoxia/hypothermia shock. Indeed, a 30%–50% decrease in these activities was observed as compared to values obtained in control hepatocytes. No difference could, however, be found at the cellular level regarding the solution used for cold storage. These results suggest that the superiority of UW over EC solution, already reported in clinical practice after transplantation of preserved human livers, was not due to a better preservation of the hepatocytes.     

Hyaluronic acid uptake in the assessment of sinusoidal endothelial cell damage after cold storage and normothermic reperfusion of rat livers

The uptake of hyaluronic acid (HA) was used to assess preservation damage to sinusoidal endothelial cells (SEC) during cold storage and subsequent normothermic reperfusion of rat livers. After 8, 16, 24, and 48 h storage in University of Wisconsin (UW) solution, livers were gravity-flushed via the portal vein with a standard volume of cold UW solution containing 50 g/l HA. The effluent was collected for analysis of HA, aspartate aminotransferase (AST), and lactate dehydrogenase (LDH). The mean uptake of HA at 0 h was 59.1%±4.6% (mean±SEM). After 8 h of storage, HA uptake was similar (55.5%±7.3%), whereas after 16 h of storage it was reduced to 34.7%±5.8%. At 24 and 48 h of storage, no uptake of HA was found. In a second series of experiments, livers were stored in UW solution and subsequently reperfused for 90 min with a Krebs-Henseleit solution (37°C) in a recirculating system containing 150 g/l HA. Following 8 h of storage, 34.6%±8.0% of the initial HA concentration was taken up from the perfusate. After 16 and 24 h of storage, no uptake of HA was found. The results of this study indicate that damage to SEC occurs progressively during storage, leading to zero uptake of HA by the rat livers at 24 h of cold ischemia time. Additional reperfusion injury to the SEC was demonstrated by the reduced ability of the SEC to take up HA following normothermic reperfusion. The uptake of exogenous HA in preserved livers, used as a tool to assess SEC injury, enables the detection of early preservation damage.     

Effect of Short-term Administration of Prostaglandin E<Subscript>1 </Subscript>on Viability after Ischemia/Reperfusion Injury with Extended Hepatectomy in Cirrhotic Rat Liver

The cytoprotective effect of prostaglandin E₁ (PGE₁) has been demonstrated experimentally and clinically against hepatic ischemia and reperfusion injury and against the effects of partial hepatectomy in both individual and combined models of noncirrhotic livers. Cirrhotic livers are more vulnerable to ischemia/reperfusion injury during hepatectomy than are noncirrhotic livers, and postoperative malfunctioning complicates life with multiple organ failure. Cirrhotic livers with tumors have mostly been treated conservatively because extended hepatectomy with induced ischemia during surgery is impossible. The purpose of our study was to document postoperative surgical adaptation in inoperable cases with improved survival after extended hepatectomy in a rat model of cirrhosis treated by PGE₁. Cirrhosis was induced by intraperitoneal injections of 1% dimethylnitrosamine. The liver was subjected to 15 minutes of total ischemia by occluding the hepatoduodenal ligament. Hepatectomy was performed during ischemia. Pretreatment with PGE₁ (0.4 g/kg/min) (or without it in the controls) was given for 15 minutes by intravenous infusion prior to inducing ischemia and during reperfusion. Portal venous flow (PVF) and liver tissue blood flow (LTBF) were measured during reperfusion. At the end of 60 minutes of reperfusion, venous blood was collected for liver function tests. The animals were followed up regarding survival for 48 hours. The PVF and LTBF were significantly improved in the PGE₁ group. The blood chemical analysis indicated that PGE₁ significantly suppressed posthepatectomy liver dysfunction. Most importantly, PGE₁ treatment markedly improved the survival rate, from 42% in the controls to 75% in the test animals at 24 hours after hepatectomy and from 17% in the controls to 58% in the test animals at 48 hours. We concluded that short-term administration of PGE₁ makes extensive hepatectomy possible under ischemic conditions in cirrhotic livers.     

Combined Flush With Histidine-Tryptophan-Ketoglutarate and University of Wisconsin Solutions in Liver Transplantation: Preliminary Results

Introduction

Ischemia reperfusion injury (IRI) is the main cause of early allograft dysfunction (EAD) and subsequent primary allograft failure (PAF).