Elimination of Kupffer cells and nafamostat mesilate rinse prevent reperfusion injury in liver grafts from agonal non-heart-beating donors

Cytoprotective Effects of Mesenchymal Stem Cells During Liver Transplantation from Donors After Cardiac Death in Rats

BACKGROUND

Liver transplantation from donors after cardiac death (DCD) might increase the pool of available organs. Recently, some investigators reported the potential use of mesenchymal stem cells (MSCs) to improve the outcome of liver transplantation from DCD. The aim of this study was to evaluate the cytoprotective effects and safety of MSC transplantation on liver grafts from DCD.

METHODS

Rats were divided into 4 groups (n = 5) as follows: 1. the heart-beating group, in which liver grafts were retrieved from heart-beating donors; 2. the DCD group, in which liver grafts were retrieved from DCD that had experienced apnea-induced agonal conditions; 3. the MSC-1 group, and 4. the MSC-2 group, in which liver grafts were retrieved as with the DCD group, but were infused MSCs (2.0 × 10⁵ or 1.0 × 10⁶, respectively). The retrieved livers were perfused with oxygenated Krebs-Henseleit bicarbonate buffer (37°C) through the portal vein for 2 hours after 6 hours of cold preservation. Perfusate, bile, and liver tissues were then investigated.

RESULTS

Bile production in the MSC-2 group was significantly improved compared with that in the DCD group. Based on histologic findings, narrowing of the sinusoidal space in the both MSC groups was improved compared with that in the DCD group.

CONCLUSIONS

MSCs could protect the function of liver grafts from warm ischemia-reperfusion injury and improve the viability of DCD liver grafts. In addition, we found that the infusion of 1.0 × 10⁶ MSCs does not obstruct the hepatic sinusoids of grafts from DCD.

A new liver graft preparation method for uncontrolled non-heart-beating donors, combining short oxygenated warm perfusion and prostaglandin E1

BACKGROUND

To resolve the shortage of donors associated with liver transplantation, the potential uncontrolled non-heart-beating donor (UNHBD) pool is expected to increase. However, warm ischemia-reperfusion injury leads to inferior survival in transplantation using the grafts from UNHBD compared with those from heart-beating donors. To overcome this problem, we developed a new method for preparation of liver grafts from UNHBDs consisting of a combination of short oxygenated warm perfusion (SOWP) and prostaglandin E1 (PGE1).

METHODS

Using an ex vivo perfusion rat model, we examined the effectiveness of this new method.

RESULTS

Using SOWP and PGE1 treatment, the total amount of bile production during reperfusion in UNHBD grafts was increased to the same level as that in the heart-beating donor grafts. The addition of PGE1 to SOWP buffer decreased aspartate aminotransferase/alanine aminotransferase and tumor necrosis factor α levels during 1 h of reperfusion. Necrosis and apoptosis were significantly decreased by SOWP + PGE1 treatment. SOWP + PGE1 ameliorated induction of mitochondrial permeability transition, and the total amount of mitochondrial cytochrome c in the SOWP + PGE1 group after reperfusion was kept significantly higher than that in the no treatment group. Cytosolic c-Jun N-terminal protein kinase activation was significantly suppressed by SOWP + PGE1. Decrease in mitochondrial Bcl-2 was suppressed by SOWP alone and SOWP + PGE1 treatment, and Bax in the mitochondria was significantly suppressed by SOWP + PGE1.

CONCLUSION

SOWP and PGE1 prior to cold preservation significantly improved the function of liver grafts that underwent warm ischemia-reperfusion injury. Therefore, this method might be useful in liver transplantation using UNHBD grafts.

The effects of gabexate mesilate on the microsurgical reconstruction of the hepatic artery in living donor liver transplantation

OBJECTIVES

Microsurgical reconstruction of hepatic artery is essential but require challenging techniques especially for living donor liver transplantation (LDLT), because the recipient artery is short, located deep, and usable vessel grafts are limited. Furthermore, hepatic artery thrombosis (HAT) can be a lethal complication. Therefore, we began the systemic administration of gabexate mesilate, a strong serine protease inhibitor. It has often been effective to treat disseminated intravascular coagulation. The purpose of this study was to examine the effects of gabexate mesilate on the microvascular reconstruction.

METHODS

From 1991 to 2009, we performed 134 microsurgical reconstructions of LDLT. This retrospective investigation of those cases divided them into four groups: group I, anticoagulation with heparin (n = 3); group II, heparin and gabexate mesilate (20 mg/kg/d; n = 26); group III, heparin and full-dose gabexate mesilate (40 mg/kg/d; n = 72); and group IV, full-dose gabexate mesilate alone (n = 33). Groups I and II were mainly pediatric cases (left lobe grafts only); groups III and IV, adult cases (left: right = 57:48). Using ultrasonography to 14 days, we investigated HAT by examining pulsatile index, resistive index, and acceleration time.

RESULTS

HAT occurred in groups I, II, III, and IV at 33.3% (1/3), 11.5% (3/26), 6.9% (5/72), and 0% (0/33), respectively. The 5-year survival rates of groups III + IV versus groups I + II were 82.4% and 71.1%, respectively (P < .05). In HAT cases, even before the event the acceleration times were delayed to over 100 milliseconds.

CONCLUSION

Gabexate mesilate administration was safe for and protective of microvascular reconstructions in LDLT.

Effects of serine protease inhibitor and prostaglandin I2 on liver transplantation from non-heart-beating rat donors

OBJECTIVES

We sought to preserve the microcirculation as a keystone in liver transplantation from a non-heart-beating donor (NHBD). The purpose of this study was to investigate the cytoprotective effects of a serine protease inhibitor, nafamostat mesilate, and prostaglandin I2 (PGI2) on livers transplanted from NHBDs.

METHODS

Male Wistar rats were used in five groups of nine rats each. In group 1, livers were retrieved from heart-beating donors (HB group); in group 2, livers were retrieved from NHBDs that had experienced agonal apnea (NHB group); in group 3, livers were retrieved in the same manner as in the NHBD group but were pretreated with nafamostat mesilate (NM), 0.2 mg/kg/h, (NM group); in group 4, livers were retrieved in the same manner as in the NHBD group but were pretreated with prostaglandin (PG) I2, 33 ng/kg/h for 30 minutes (PG group); and in group 5, livers were retrieved in the same manner as in the NHBD group but were pretreated with NM plus PG, (NM+PG group). Livers were perfused for 60 minutes with Krebs-Henseleit bicarbonate buffer after 6 hours of cold preservation, after which the perfusate and liver tissue were analyzed in one set of experiments. In another set of experiments, livers retrieved and after 1 hour of cold preservation were transplanted according to the Kamada method.

RESULTS

In the NM+PG group, the values of interleukin-1beta, tumor necrosis factor-alpha, and thromboxane B2 were significantly lower than those in the NHB group. At histologic analysis, sinusoidal endothelial cells were well preserved in the NM+PG group. The number of survivors at 7 days after liver transplantation in the 5 groups were 9, 0, 1, 1, and 3, respectively.

CONCLUSION

The serine protease inhibitor, NM, and PGI2 supported sinusoidal endothelial cells and preserved microcirculation.

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.

Reperfusion injury in liver transplantation

Reperfusion injury occurring in the transplanted liver is a complex lesion and has been the focus of considerable research over the past decade. This section will review recent major developments in understanding the mechanisms involved and their application to clinical transplantation.

Primary graft nonfunction and Kupffer cell activation after liver transplantation from non-heart-beating donors in pigs

More extensive use of non-heart-beating donors (NHBD) could reduce mortality on liver transplantation waiting lists, but this is associated with more primary nonfunction (PNF). We assessed which parameters are involved in the development of PNF in livers from NHBD in a previously validated pig liver transplantation model, in which livers were transplanted after exposure to incremental periods of warm ischemia. The risk of PNF was unacceptably high (>50%) when livers were exposed to >30 minutes' warm ischemia before a short cold ischemic period. This study examined how PNF is affected by Kupffer cell activation (beta-galactosidase), the generation of cytokines tumor necrosis factor alpha and interleukin 6, antioxidant mechanisms (ascorbic acid, alpha-tocopherol, reduced glutathione), circulating redox-active iron, and sinusoidal endothelial cell function (hyaluronic acid clearance). Kupffer cells were more activated in PNF recipients, as suggested by higher beta-galactosidase levels (15 minutes after reperfusion), and secondarily, by higher production of tumor necrosis factor alpha and interleukin 6 (180 minutes after reperfusion). In addition, alpha-tocopherol and reduced glutathione were lower, and ascorbic acid and redox-active iron higher in PNF recipients. Finally, PNF grafts displayed progressively decreasing hyaluronic acid clearance (suggesting sinusoidal endothelial cell dysfunction) and parenchymal edema. Consequently, a reduced-flow phenomenon was documented. In grafts from NHBD that are destined to fail, beta-galactosidase activity (a surrogate of Kupffer cell activation) is higher, proinflammatory cytokines are overproduced, some antioxidant mechanisms fail, and circulating redox-active iron is more rapidly released. A no-flow phenomenon is eventually observed in these failing grafts.

The Effect of Perfusion Prior to Cold Preservation and Addition of Biliverdin on the Liver Graft from Non-Heart-Beating Donors

AIM

Our aim was to improve the energy status and viability of a liver graft from a non-heart-beating donor (NHBD), we investigated the effects of perfusion prior to cold preservation and the addition of an antioxidant, biliverdin.

METHODS

Rats were divided into five groups: group 1: without 30 minutes warm ischemia (WI) and cold preservation (control group); group 2 without WI and with 6 hours of cold preservation in UW solution (HBD group); group 3 with WI and cold preservation (NHBD group); group 4 with 30 minutes perfusion prior to cold preservation (PRE group); and group 5 with addition of biliverdin to precold preservation perfusion (BV group). Oxygenated Klebs-Henseleit solution was used as the perfusate prior to and after preservation. Portal flow and bile production during reperfusion, energy charge (EC), ATP level, GOT, and TNF-alpha were measured as well as a histological evaluation.

RESULTS

Portal flow of the PRE and BV groups during 1 hour of reperfusion was higher than of that the NHBD group. Bile production of the PRE group was also higher than that of the NHBD group, but bile production in the BV group was comparable to the NHBD group. EC of the PRE group was higher than that of the NHBD group prior to and after reperfusion. The EC and ATP levels of the BV group after reperfusion were higher than those of the NHBD and PRE groups. The GOT and TNF-alpha were reduced in the BV group.

CONCLUSIONS

Precold preservation perfusion improves the viability of grafts from NHBDs. Furthermore, biliverdin exerted an additive effect to ameliorate energy status.

Liver transplantation from non-heart-beating donors: current status and future prospects

Liver transplantation is the treatment of choice for many patients with acute and chronic liver failure, but its application is limited by a shortage of donor organs. Donor organ shortage is the principal cause of increasing waiting lists, and a number of patients die while awaiting transplantation. Non-heart-beating donor (NHBD) livers are a potential means of expanding the donor pool. This is not a new concept. Prior to the recognition of brainstem death, organs were retrieved from deceased donors only after cardiac arrest. Given the preservation techniques available at that time, this restricted the use of extrarenal organs for transplantation. In conclusion, after establishment of brain death criteria, deceased donor organs were almost exclusively from heart-beating donors (HBDs). To increase organ availability, there is now a resurgence of interest in NHBD liver transplantation. This review explores the basis for this and considers some of the published results.

Effects of anti-inflammatory cytokine agent (FR167653) and serine protease inhibitor on warm ischemia-reperfusion injury of the liver graft

BACKGROUND

The shortage of donors has become a serious problem. Some institutes have tried to use grafts retrieved from non-heart-beating donors (NHBDs), but the results have not been satisfactory. This study clarifies the effects of nafamostat mesilate (NM), a strong serine protease inhibitor, and FR167653, a suppressant of both tumor necrosis factor-alpha and interleukin-1beta release, on warm ischemia-reperfusion injury and establishes the procurement of the grafts for a successful liver transplant using uncontrolled NHBDs.

METHODS

Male Wistar rats were divided into five groups as follows (n = 5): (1) heart-beating (HB) group, in which livers were retrieved from heart-beating donors; (2) non-heart-beating (NHB) group, in which livers were retrieved from NHBDs; (3) NM group, in which livers were retrieved from NHBDs pretreated with NM (0.2 mg/kg/hr, for 30 min); (4) FR group, in which livers were retrieved from NHBDs pretreated with FR167653 (2 mg/kg); and (5) FR+NM group, in which livers were retrieved from NHBDs pretreated with FR167653 and NM. The livers were perfused for 60 min with Krebs-Henseleit bicarbonate buffer after cold preservation 6 hr.

RESULTS

In the NHB group, the values of interleukin-1beta, tumor necrosis factor-alpha, thromboxane B2, and leukotriene B4, and the expressions of nuclear factor-kappaB, activating protein 1, and cyclooxygenase-2 were significantly higher than those in the HB group. In the FR+NM group, those values were low, the structure of the sinusoids was preserved, and the sinusoidal lumen was maintained (the same as observed in the HB group).

CONCLUSIONS

FR167653 and NM inhibited the induction of inflammatory cytokines and arachidonic acid cascade mediators. This combined therapy was effective in preserving sinusoidal microcirculation in the liver grafts from NHBDs.

Gadolinium chloride and salvia miltiorrhiza compound ameliorate reperfusion injury in hepatocellular mitochondria

AIM: To investigate the effect of gadolinium chloride (GaCl₃) and salvia miltiorrhiza compound (SMCo) on ischemia and reperfusion (I/R) injury in hepatocellular mitochondria.

METHODS: Wistar rats were randomly to divided into control group, GaCl₃ group, SMCo group and GaCl₃ + SMCo group (n = 15 each). GaCl₃ (7 mg·kg^-1) was injected into tail vein on d 1 and d 2 in contrast group. SMCo (2 mL·kg^-1) was injected into muscle on d 1 and d 2 in SMCo group. GaCl₃ + SMCo group received both GaCl₃ (iv) and SMCo (im) injection. Control group received saline injection only. On d 3, all the rats were subjected to 2 h ischemia in the middle and left lobes of the liver, followed by reperfusion for 2 h, 6 h and 18 h respectively. The level of serum alanine aminotransferase (ALT) and malondialdehyde (MDA) in hepatocellular mitochondria was measured. Pathological changes in hepatic tissue and in hepatocellular mitochondria were determined with optical microscope and electronic microscope, respectively.

RESULTS: Remarkablly pathohistological and biochemical changes were detected after 6 h of I/R. Compared with control, the level of ALT was decreased in GaCl₃, SMCo and GaCl₃ + SMCo treated groups (1314.0 ± 278.7 vs 809.4 ± 196.1, 716.6 ± 242.8 and 837.2 ± 190.6 IU·L^-1, respectively. P < 0.05). Similarly, the level of MDA was decreased in GaCl₃, SMCo and GaCl₃ + SMCo treated groups (293.1 ± 51.1 vs 190.8 ± 55.5, 214.3 ± 32.9 and 221.0 ± 47.3 nmol·g^-1, respectively, P < 0.05). Accordingly, in control group, swelling, degeneration, focal necrosis, infiltration of leucocyte were found in reperfused tissue under an optical microscope, and mitochondria swelling, rupture and even breakdown were seen under an electronic microscope. These pathohistological and ultrastructural damages caused by I/R were greatly attenuated in GaCl₃, SMCo and GaCl₃ + SMCo treated groups. However, there was no additive effect observed when GaCl₃ and SMCo were used together.

CONCLUSION: Both GaCl₃ and SMCo can alleviate the I/R injury in hepatocellular mitochondria.

Successful liver transplantation from agonal non-heart-beating donors in pigs

An effective way to overcome shortage of donors in liver transplantation (LTx) is to consider such from non-heart-beating donors (NHBDs). We investigated how a liver graft should be treated before and/or after procurement for successful LTx from an NHBD. Porcine LTx was performed with FR167653 (FR), a dual inhibitor of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta), and/or prostaglandin E(1) (PG). Animals were allocated to an FR group (n=4, donors and recipients were treated with FR), a PG group (n=4, donors and recipients were treated with PG), or an FRPG group (n=4, donors and recipients were treated with both FR and PG). No recipients in the FR group and only two of four recipients in the PG group survived, whereas all recipients in the FRPG group survived. Suppression of TNF-alpha and IL-1beta and maintenance of microcirculation are the key to successful transplantation from NHBDs.

Prediction of graft viability from non-heart-beating donor pigs using hepatic microdialysate hypoxanthine levels

BACKGROUND

Non-heart-beating donors (NHBDs) are not yet acceptable in orthotopic liver transplantation (OLTX) because of the high frequency of primary graft nonfunction. In this study, we aimed to develop a new predictive method of graft viability in OLTX from NHBDs.

MATERIALS AND METHODS

(1) Pigs were subjected to 15 min of hepatic ischemia and reperfusion (I/R). (2) Porcine OLTX was performed using grafts obtained from NHBDs subjected to in situ warm ischemia (0, 30, and 60 min). During both operations, hepatic hypoxanthine levels were measured by a microdialysis method.

RESULTS

In the I/R model, hypoxanthine accumulated during ischemia and decreased after reperfusion, whereas marked xanthine and uric acid production were observed after reperfusion. In the NHBDs model, all of the 0-min group, 6 of 13 pigs in the 30-min group, and 1 of 6 pigs in the 60-min group survived more than 7 days. Significant increases of hypoxanthine levels were seen dependent on warm ischemic time. In the 30-min group, hypoxanthine levels were significantly higher in the pigs that died than in those that survived, and correlated with aspartate aminotransferase, lactate dehydrogenase, and adenosine triphosphate levels of recipients. Histological examination revealed that graft injury was severe in the pigs with higher hypoxanthine levels.

CONCLUSIONS

It is suggested that hepatic microdialysate hypoxanthine levels during warm ischemia in NHBDs were correlated with graft viability in the recipient. By using of this technique, prediction of the graft viability may be possible during donor operation.

Kupffer cells play an important role in the cytokine production and activation of nuclear factors of liver grafts from non-heart-beating donors

In the non-heart-beating donor (NHBD) deterioration of microcirculation of the liver graft is strongly associated with secretion of cytokines and eicosanoids. In this study we investigated the excretion of cytokines, eicosanoids, and DNA binding activity of transcription factors in the grafts from NHBD and evaluated the effects of the elimination of Kupffer cells on them. The purpose of this study was to clarify the impact of Kupffer cells on transcription factor activity and the that of cytokine and eicosanoid production on reperfusion injury of liver grafts from NHBD. Wistar rats were allocated to four groups: (a). control group: livers were extracted under heart-beating conditions and perfused without cold storage, (b). heart beating (HB) group: livers extracted under heart-beating conditions were perfused after 6 h of cold storage, (c). non-heart-beating (NHB) group: livers extracted after cardiac arrest were perfused after cold storage, (d). Kupffer cell eliminated (KE) group: liposome-encapsulated dichloromethylene diphosphonate was intravenously administered to eliminate Kupffer cells before extraction, and the liver was perfused after cold storage. Cytokines and eicosanoids in perfusate were measured. DNA binding activity of nuclear factor kappa B, activating protein 1, and nuclear factor-interleukin 6 of tissue were investigated. Concentrations of interleukin 1 beta and thromboxane B(2) in the perfusate were significantly higher in NHB group, but they were completely suppressed in the KE group. A rise in binding activity of nuclear factor kappa B and activating protein 1 was not observed during cold storage in any groups, but these activities did increase remarkably after reperfusion. Significant buildup of those activities were recognized in the NHB group, and this phenomenon was inhibited in the KE group. The histological structures of the sinusoid in the KE group were well maintained, as with those of the control group. These results indicate that cytokines, eicosanoids, and the DNA binding activity of the transcripton factor are strongly associated with reperfusion injury, and Kupffer cells play an important role in this mechanism in grafts from NHBDs.

Influence of humoral immunoreaction on hepatic nonparenchymal cells in ex situ xenoperfused rat livers

BACKGROUND

The influence of xenogeneic humoral immunoreaction on hepatic nonparenchymal cells (NPCs) was evaluated ex situ in xenoperfused rat livers.

METHODS

Isolated rat livers were perfused via the portal vein (PV) for 240 min. The perfusates consisted of fresh rat blood (group 1), fresh human blood (group 2), and fresh human blood containing 5 microg/mL soluble complement receptor type 1 (Group 3).

RESULTS

Deposition of human IgM and C(5b-9) complement was observed in group 2, although only human IgM deposition was detected in group 3. Portal vein pressure in group 2 rose drastically during the first 10 min. Creatine kinase BB component gradually increased in all groups, followed by an elevation in alanine aminotransferase and both parameters were significantly higher in group 2 than in groups 1 and 3. In group 2, platelet thrombi in the peripheral PVs and periportal hemorrhage were observed after 10 min, and massive necrosis around the central veins after 240 min; these changes were not observed in group 1 or 3. Production of tumor necrosis factor alpha and alpha interferon and expression of intercellular adhesion molecule 1 (ICAM-1) were lower in group 2 than in groups 1 and 3. In group 2, there were negative areas for ICAM-1 and tumor necrosis factor alpha staining around the central veins after 240 min, which were consistent with necrotic areas.

CONCLUSIONS

In xenoperfused rat livers, humoral mediators initially caused the disturbance of microcirculation, which would induce long ischemia in the pericentral areas, resulting in massive necrosis. NPC necrosis may be responsible for less production of cytokines and adhesion molecules in the xenoperfused livers.

Susceptibility of liver allografts to high or low concentrations of preformed antibodies as measured by flow cytometry

Liver grafts are more resistant to damage by HLA antibodies than other organ allografts, but it is not clear if the antibodies are associated with graft rejection or graft loss, or if different antibody concentrations have different effects. To explore potential associations between antibody concentrations and outcome, preformed IgG antibodies against donor cells were quantified by flow cytometry in 465 consecutive liver transplant recipients. Antibody-positive patients were classified according to whether they had high or low antibody concentrations and analyzed for possible correlation with graft rejection or graft loss. The results showed that the incidence of rejection was not significantly different between antibody-positive and negative patients. However, patients with high antibody concentrations had a higher incidence of steroid-resistant rejections (31% at 1 year) than patients with low antibody (4%) or no antibody (8%, p < 0.0004). These effects were mainly due to T-cell (HLA class 1) antibodies. The overall incidence of rejection at 1 year was 69% for high antibody patients, 51% for patients with low antibodies and 53% for patients with no antibodies (p not significant). In an apparent paradox, antibody-positive patients underwent fewer early graft losses. Thus, the associations of preformed antibodies and outcome depend, on the one hand, on antibody concentrations, and on the other hand on whether the outcome measured is steroid-sensitive rejection, steroid-resistant rejection or graft survival. These complex interactions may explain the controversial results observed in previous studies.

Role of hepatocytes and bile duct cells in preservation-reperfusion injury of liver grafts

In liver transplantation, it is currently hypothesized that nonparenchymal cell damage and/or activation is the major cause of preservation-related graft injury. Because parenchymal cells (hepatocytes) appear morphologically well preserved even after extended cold preservation, their injury after warm reperfusion is ascribed to the consequences of nonparenchymal cell damage and/or activation. However, accumulating evidence over the past decade indicated that the current hypothesis cannot fully explain preservation-related liver graft injury. We review data obtained in animal and human liver transplantation and isolated perfused animal livers, as well as isolated cell models to highlight growing evidence of the importance of hepatocyte disturbances in the pathogenesis of normal and fatty graft injury. Particular attention is given to preservation time-dependent decreases in high-energy adenine nucleotide levels in liver cells, a circumstance that (1) sensitizes hepatocytes to various stimuli and insults, (2) correlates well with graft function after liver transplantation, and (3) may also underlie the preservation time-dependent increase in endothelial cell damage. We also review damage to bile duct cells, which is increasingly being recognized as important in the long-lasting phase of reperfusion injury. The role of hydrophobic bile salts in that context is particularly assessed. Finally, a number of avenues aimed at preserving hepatocyte and bile duct cell integrity are discussed in the context of liver transplantation therapy as a complement to reducing nonparenchymal cell damage and/or activation.

Controlled non-heart-beating donor liver transplantation: a successful single center experience, with topic update

BACKGROUND

The critical shortage of transplantable organs necessitates utilization of unconventional donors. We describe a successful experience of controlled non-heart-beating donor (NHBD) liver transplantation.

METHODS

Controlled NHBDs had catastrophic head injury, prognosis for no meaningful recovery, decision to withdraw life support, and subsequent consent for donation. After stopping mechanical ventilation in the operating room, death determination by a nontransplant caregiver, and rapid aortic cannulation, liver and kidneys were recovered.

RESULTS

Controlled NHBDs contributed 5% of hepatic allografts (8/164) from August 1996 through June 1999 (9% in 1998). Sixteen NHBDs afforded 8 livers and 24 kidneys. Liver donors (n=8) were 11-66 years old; half were >50 years old. Premortem alanine aminotransferase was 25-157 U/L. Arrest occurred 3-27 min after stopping ventilation. Perfusion started 3-5 min after incision, and <22 min after hypotension (mean arterial pressure: <50 mmHg). Patient and graft survivals are 100% at 18+/-12 months follow-up. There was no intraoperative complication, reperfusion syndrome, poor graft function, primary nonfunction, arterial thrombosis, biliary complication, or serious infection. Postoperative day 2 prothrombin time was 13+/-1 sec. Peak alanine aminotransferase was 980+/-601 U/L. Intensive care unit and posttransplant lengths of stay were 2+/-2 and 10+/-7 days, respectively. Soon after transplantation there was frequent temporary hyperbilirubinemia (five of eight recipients; bilirubin peak: 7-29 mg/dl, 2-3 weeks after transplantation) and rejection (4/8 recipients, <3 weeks after transplantation).

CONCLUSIONS

NHBDs significantly and safely expanded our donor pool. NHBD surgeons must be capable of rapid procurement. Cautious liberalization of criteria for accepting livers from NHBDs with confounding risk factors is justified. Refined ethics guidelines would broaden approval of NHBDs.

Pharmacologic graft protection without donor pretreatment in liver transplantation from non-heart-beating donors

BACKGROUND

Non-heart-beating donors (NHBDs) are considered potential sources of transplant organs in an effort to alleviate the problem of donor shortage in clinical liver transplantation. We investigated the possibility of pharmacologic protection of hepatic allograft function from NHBDs without donor pretreatment.

METHODS

Orthotopic liver transplantation was performed using pigs. In donors, cardiac arrest was induced by stopping the respirator. Forty-five minutes after cessation of the respirator, the liver was flushed with cold lactated Ringer's solution including heparin and with the University of Wisconsin (UW) solution, and then preserved for 8 hr at 4 degrees C in the UW solution. The pigs were divided into two groups: a control group and a treated group. In the treated group, an endothelin antagonist TAK-044 was added to the UW solutions (10 mg/L), and TAK-044 (10 mg/kg body weight) and a platelet activating factor antagonist E5880 (0.3 mg/kg body weight) were also administered to the recipients.

RESULTS

TAK-044 and E5880 treatment significantly increased the 7-day survival rate of the recipients (100% vs. 17%, P<0.05). In the treated group, portal venous pressure immediately after reperfusion of the graft was significantly lower than in the control group, and postoperative increase in serum concentrations of glutamic oxaloacetic transaminase and total bilirubin was attenuated. Moreover, the energy charge and adenosine triphosphate concentration of the liver were rapidly restored after reperfusion.

CONCLUSIONS

Pharmacologic modulation with TAK-044 and E5880 avoiding donor pretreatment can improve the viability of hepatic allografts procured from NHBDs.