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

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

冷保存大鼠部分肝移植模型的建立

目的　建立稳定的大鼠部分肝移植模型 ,研究冷保存对部分肝移植后肝再生的影响。方法　采用雄性SD大鼠 ,双袖套法行部分肝移植 ,观察不同冷保存时间受体生存状况以及各组手术情况。结果　各组移植肝平均体积为 62 % -64 % ,无肝期为 14 -15min。长时间冷保存后大鼠 7d存活率明显下降 ,生存分析显示各组间差异有显著性。 8h冷保存后大鼠 7d存活率为 40 % ,与临床辟裂式肝移植 1年生存率相似。结论　 8h保存大鼠部分肝移植模型是研究冷保存对部分肝移植肝再生影响的较好模型     

Effects of portal vein clamping time on rat liver microcirculation following extended cold preservation and transplantation

Orthotopic rat liver transplantation (ORLT) following extended cold preservation in University of Wisconsin (UW) solution has been shown to induce alterations of the hepatic microcirculation, mainly characterized by areas of no-reflow. The present study was performed to determine whether these alterations were related to the portal vein clamping time (PVCT), shown to be the main determinant of survival after ORLT. The hepatic microcirculation was evaluated using the multiple-indicator dilution curve (MIDC) technique after ORLT following 24-hour cold ischemia in UW solution. Two groups of rats were studied: one with PVCTs of less than 14 min (survival conditions) and one with PVCTs of more than 18 min (nonsurvival conditions). Four hours after ORLT, only long PVCTs were associated with small, but significant, nonperfused areas, about 10 % of the liver not being perfused by water; however, in both survival and nonsurvival conditions, the sinusoidal sieving function was well-maintained in perfused areas. In addition, liver viability parameters and hepatocyte function were similarly and minimally altered. The hepatic microcirculation is minimally altered 4 h after ORLT following extended cold preservation in UW solution, whatever the survival condition. Although only found after long PVCTs, the low magnitude of areas of no-reflow should not be associated with lethal injury of the transplanted liver, a finding further supporting the concept that survival after ORLT following 24-hour cold preservation in UW solution is mainly influenced by extrahepatic factors. Received: 1 December 1998 Received after revision: 6 May 1999 Accepted: 19 July 1999     

冷保存供肝肝移植大鼠肝窦内皮细胞损伤机制的研究

目的 探寻肝移植大鼠肝窦内皮细胞(SEC)损伤的详细过程、方式及机制,为冷保存再灌注损伤的保护研究开辟新的途径.方法 雄性SD大鼠随机分为假手术组(n=6)、UW 1 h肝移植组(n:48)、Uw 12 h肝移植组(n=48).大鼠原位肝移植采用双袖套法,分别于术后不同时相点采取血液及组织标本,检测血清丙氨酸氨基转移酶(ALT)及透明质酸(HA)水平;HE染色观察肝脏病理学变化;TUNEL法检测凋亡,免疫组化法检测Bcl-2及Cleaved Caspase-3的表达状况.结果 UW 1 h、UW 12 h组肝移植后血清ALT、HA均较假手术组明显升高(P<0.05),UW 12 h组又明显高于Uw 1 h组(P<0.05).UW 12 h组ALT水平于术后6 h达高峰,而HA水平却在术后1 h、24 h呈双峰表现.Uw 12 h组首先出现SEC的凋亡继而出现肝细胞的坏死,且UW 12 h组细胞凋亡指数(apoptosis index,AI)明显高于UW 1 h组(P<0.01).两组大鼠SEC的AI均于术后6 h达高峰,与血中ALT的高峰时相点一致.肝移植术后Bcl-2表达明显减弱(P相似文献   

Successful extended hypothermic cardiopulmonary preservation for heart-lung transplantation

The inability to obtain sufficiently extended hypothermic organ preservation is a major restriction on clinical heart-lung transplantation. We used core cooling, nonrecirculating retrograde heart perfusion, and lung immersion with liposomal recombinant human superoxide dismutase in an attempt to provide effective 12-hour cardiopulmonary preservation. Donor dogs supported by cardiopulmonary bypass were rapidly cooled to 15 degrees C with cardioplegic arrest, and heterotopic heart and unilateral left lung transplantations were performed. In control dogs (n = 7), hearts and lungs, harvested after core cooling and cardioplegic arrest, were transplanted with a total mean ischemic time of 88 +/- 5 minutes. In group II (n = 7), heart-lung blocks were similarly excised but preserved at 4 degrees C for 12 hours (756 +/- 30 minutes) and then transplanted. During preservation, the lungs were immersed in hyperosmolar extracellular solution. For the heart, retrograde coronary sinus perfusion was performed with intracellular solution containing perfluorochemicals at a temperature of 4 degrees C and a rate of 30 ml/hr for 12 hours. In group III (n = 7), donor organs were similarly excised and preserved for 12 hours (726 +/- 39 minutes), except that liposomal recombinant human superoxide dismutase was administered during harvest, preservation, and reperfusion. Myocardial function, assessed by the ratio of end-systolic pressure to end-systolic dimension, after the 12-hour preservation period in both experimental groups was similar to that of the control group 4 and 6 hours after transplantation. The mean arterial oxygen capacity of the transplanted left lung during ventilation with an inspired oxygen concentration of 40% was also similar in each group. In contrast, the 12-hour preservation of pulmonary function assessed by pulmonary vascular resistance, the accumulation of extravascular lung water, and histologic evidence of alveolar wall injury, interstitial edema, and perivascular hemorrhage were significantly impaired in the absence of liposal recombinant human superoxide dismutase. These findings suggest that successful extended cardiopulmonary preservation for heart-lung transplantation is possible with core cooling, nonrecirculating retrograde heart perfusion, and hypothermic lung immersion incorporating liposomal recombinant human superoxide dismutase.     

Apoptosis and regeneration of sinusoidal endothelial cells after extended cold preservation and transplantation of rat liver

BACKGROUND: Sinusoidal endothelial cells (SECs) are particularly susceptible to cold ischemia-reperfusion (I/R) injury. We have examined the process of injury and recovery of graft after cold-preserved liver transplantation, with special focus on the proliferation of SECs and regulatory mechanisms involved. METHODS: Male SD rats were divided into two groups according to length of cold preservation time in University of Wisconsin [UW] solution of graft: UW1h group and UW12h group. Graft function, incidence of apoptosis, proliferation of SECs and the expression of related regulatory factors were assessed after orthotopic liver transplantation (OLT). RESULTS: SECs are more sensitive to apoptosis induced by cold I/R injury compared with hepatocytes. Using bromodeoxyuridine and rat endothelial cell antigen-1 double immunostaining assay, SECs exhibited a delayed proliferation in comparison with hepatocytes, reaching a peak at 72 hr in UW1h group and 96 hr in UW12h group, respectively. Vascular endothelial growth factor increased at 24 hr after reperfusion, and peaked at 72 hr in both groups. Flt-1 and flk-1 expression was found to be mainly limited to SECs, with a peak in expression occurring between 72 and 96 hr, which coincided with the peak in SEC proliferation in UW1h group. However, flt-1 was found to be reduced significantly at any time throughout the experiments in UW12h group compared to sham. CONCLUSION: The delayed recovery of rat liver after extended cold preservation and transplantation correlates with a retarded regeneration of SECs due to increased apoptosis and reduced expression of flt-1. These results suggest that SECs play an important role in cold-preserved liver transplantation.     

The impact of liver reductions in pediatric liver transplantation

Reduced-size liver transplantation (RSLT) in children was introduced to alleviate a shortage of small-organ donors. The impact of RSLT on the waiting time for an organ and on morbidity and mortality was investigated. Between March 25, 1988, and August 11, 1990, 61 hepatic transplantations were performed in 55 children at the Pacific Transplant Institute in San Francisco, Calif. Full-size liver transplantation was performed in 41 cases and RSLT in 20 cases. The overall 30-month actuarial patient and graft survival rates were 89% and 73%, respectively. A comparison between full-size liver transplantation and RSLT showed no difference in patient and graft survival, reoperations, infections, or rejection. Benefits of RSLT were an increase in the donor pool size, a decrease in waiting time for a suitable donor, and a decrease in the rate of arterial thrombosis. The main morbidity of RSLT was an increase in perioperative blood requirement. We conclude that RSLT offers small children with end-stage liver disease a chance for long-term survival.     

The impact of donor age on living donor liver transplantation

BACKGROUND: The impact of the age of the donor on the outcome of living related liver transplantation is yet to be clarified. METHODS: During October 14, 1996 and December 20, 1999, 34 living related liver transplantations were performed. Of these, 26 cases were performed using the extended left lobe graft, which were classified into three groups; younger donor group (group Y, donor age < 30, n = 7), middle-aged donor group (group M, 30 < or = donor age <50, n=13), and older donor group (group O, donor age < 50, n = 6). Early allograft function and regeneration were compared between these groups. RESULTS: There was no difference in standard liver volume, and predicted or harvested graft size between the three groups. Although serum transaminase and total bilirubin levels within postoperative day 7 were not different between the groups, the prothrombin time on postoperative day 3 was significantly longer in group O than in group Y. One week after transplantation, group Y had significantly greater graft/standard liver volume ratio than group O, and greater graft volume than group M and O. One month after transplantation, however, there was no significant difference in such graft size parameters between the groups. Graft and patient survival were comparable between the three groups. CONCLUSION: Although function and regeneration of the allografts from older donors in living donor liver transplantation is worse than those of their younger counterparts, the outcome is not affected by the age of the liver.     

肝移植中应用ABO血型不合供肝的初步经验

目的 探讨急诊状况下ABO血型不合肝移植的疗效及其预后影响因素.方法 410例原位肝移植中有8例为ABO血型不合的急诊肝移植,其中受体血型O型5例、非O型3例.术后以四联免疫抑制剂抗排斥反应,观察受体急性排斥反应、血管、胆道并发症、感染和肝肾功能情况.结果 患者半年存活率为50%,围手术期死亡率为50%.受体血型O型和非O型、MELD（model for end-stage liver disease）评分＜30分和≥30分、CTP（Child-Turcotte-Pugh）评分＜13分和≥13分、重型肝炎和非重型肝炎、脾切除和非脾切除患者的半年存活率分别为80%和0%、50%和33%、75%和25%、25%和75%、33%和60%.术后并发症有：急性排斥反应1例;胆漏1例;肝叶坏死和肝脓肿2例;肾功能衰竭2例;感染6例（2例为曲霉菌感染）.结论 ABO血型不合肝移植预后不佳,围手术期死亡率高,因此仅适用于无法及时获得合适供肝的急诊肝移植.     

Successful transplantation of rat hearts subjected to extended cold preservation with a novel preservation solution

Since prolonged cold preservation of the heart deteriorates the outcome of heart transplantation, a more protective preservation solution is required. We therefore developed a new solution, named Dsol, and examined whether Dsol, in comparison to UW, could better inhibit myocardial injury resulting from prolonged cold preservation. Syngeneic heterotopic heart transplantation in Lewis rats was performed after cold preservation with UW or Dsol for 24 or 36 h. In addition to graft survival, myocardial injury, ATP content, and Ca(2+) -dependent proteases activity were assessed in the 24-h preservation group. The cytosolic Ca(2+) concentration of H9c2 cardiomyocytes after 24-h cold preservation was assessed. Dsol significantly improved 7-day graft survival after 36-h preservation. After 24-h preservation, Dsol was associated with significantly faster recovery of ATP content and less activation of calpain and caspase-3 after reperfusion. Dsol diminished graft injury significantly, as revealed by the lower levels of infarction, apoptosis, serum LDH and AST release, and graft fibrosis at 7-day. Dsol significantly inhibited Ca(2+) overload during cold preservation. Dsol inhibited myocardial injury and improved graft survival by suppressing Ca(2+) overload during the preservation and the activation of Ca(2+) -dependent proteases. Dsol is therefore considered a better alternative to UW to ameliorate the outcome of heart transplantation.     

自制肝脏保存液在大鼠原位肝移植模型中的应用

目的研制一种新型的专用于肝脏保存的溶液,以期达到价廉、专用、损伤小并能长时间保存的目标。方法自制肝脏保存液;建立大鼠原位肝移植模型;使用自制肝脏保存液(A组)、UW液(B组)和HC-A液(C组)保存大鼠肝脏2、8、24h后行大鼠原位肝移植,于移植后6 h比较各项肝脏功能。结果对于ALT、AST、HA,自制肝脏保存液组及其亚组与UW液组同步升高(P>0.05),与HC-A液组比较,前者的含量均低,差异有统计学意义(P<0.05)。对于LDH、STB,自制肝脏保存液组及其亚组与HC-A液组同步升高(P>0.05),与UW液组比较,前者的含量均高(P<0.05)。结论经大鼠原位肝移植模型证实,自制肝脏保存液与UW液在保护肝脏功能方面作用相当,优于HC-A液。