Celsior液和UW液保存供肝的前瞻性随机对照研究

目的比较Celsior液和UW液保存供肝的效果。方法随机选取拟行肝移植的患者60例，平均分为两组，一组接受以Celsior液灌洗和冷保存的供肝（Celsior液组）移植，另一组接受以UW液灌洗和冷保存的供肝（UW液组）移植，两组在患者年龄、性别构成、肝功能分级以及原发病、肝移植术式等方面的差异无统计学意义。比较两组供肝组织学变化、术后早期肝功能恢复情况及术后3个月内缺血性胆道狭窄的发生率。结果Celsior液组供肝冷缺血时间为（8．83±1．53）h，UW液组为（9．08±1．85）h，差异无统计学意义（P〉0．05）。两组术后早期血清丙氨酸转氨酶、天冬氨酸转氨酶、γ-谷氨酰转移酶、胆红素总量、出血时间及胆汁量的差异无统计学意义（P〉0．05），术后3个月内，Celsior液组缺血性胆道狭窄发生率为6．7％（2／30），UW液组为13．3％（4／30），差异无统计学意义（P〉0．05）。两组移植肝的组织学改变相似。结论在冷缺血时间一致的情况下，Celsior液保存供肝的效果与UW液相同。     

肝移植供肝保存新途径：机械灌注

肝移植是治疗终末期肝病最有效的方法,但由于供肝短缺形势严峻,进一步发展并完善新的离体肝脏保存技术成为必然。机械灌注（MP）是一种新型的供肝保存方法,与传统的静态冷保存相比,能更好地保存离体肝脏,甚至可以挽救非标准供肝,从而进一步扩大供肝池。根据温度不同,MP可以分为低温、亚低温以及常温3种类型。目前针对肝移植的MP尚处于临床试验阶段,其主要技术参数仍需要进一步探索验证。总之,MP为解决供肝短缺提供了新思路,为了获得临床应用仍需要进一步研究,使其简化并合理优化灌注参数。     

肝移植供肝保护的研究进展

如何提高代肝保护质量、降低肝移植体保存一再灌注损伤、改善肝移植效果是当前学者关注的重要课题。本文从供肝保存液的合理配制、供肝保存方法的改进及供肝预处理三方面详细阐述了如何有效提高供肝保护质量。     

供肝的保存

安全有效的供肝保存是肝移植成功的先决条件，保存目的是使离体缺血的肝脏保持活力，以完成运送、供受体配型及手术。肝脏是生命支持器官．移植后必须立即恢复功能，所以对保存质量要求很高。     

大鼠供肝冷缺血时间与肝移植术后受者肺损伤的关系

目的 探讨大鼠供肝冷保存时间与肝移植术后受者肺损伤的关系。方法 用Wismr大鼠建立原位肝移植模型，按供肝冷保存时间的不同分为5组（n=10），A组为假手术组，B组、C组、D组及E组的供肝冷保存时间分别为45min、90min、120min及180min。各组大鼠在移植肝恢复血流180min后处死，观察肺组织病理学变化，测定肺组织湿干重比值（W／D）、肺组织中髓过氧化氢酶（MPO）的活性，同时检测肝脏流出道血清肿瘤坏死因子（TNF-α）和白细胞介素18（IL-1β）的水平以及肺组织中TNF-α和IL-1β的表达。结果随着供肝冷保存时间的延长，肝脏流出道血清TNF-α和IL-1β水平及肺组织中TNF-α和IL-1β的表达均逐渐升高，肺组织W／D和MPO活性逐渐增高，肺损伤加重。结论供肝冷缺血时间与肝移植术后受者肺损伤相关，肺损伤随供肝冷缺血时间的延长而加重；血清中TNF-α和IL-1β升高及肺组织中TNF-α和IL-1β表达上调可能与肝移植后的肺损伤有关。     

供肝保存与功能维护助力肝移植发展

肝移植作为终末期肝病的有效治疗方法已在世界范围内广泛开展,并逐渐取得普遍认可。随着肝移植手术技术趋于成熟,术后并发症发生率逐步降低,受者的短期和长期预后持续改善。然而,器官的供应与需求之间一直存在着巨大鸿沟,是限制肝移植手术开展的重要原因。国内肝移植手术量逐年上升,供肝短缺问题日益突出,边缘供肝越来越多地应用于临床。近年来,供者器官的选择标准、器官的保存及功能维护技术不断完善。本文将从供肝保存、功能维护两方面,结合二者近年来的技术发展和研究成果,评述不同技术的应用情况和发展趋势,为进一步提高移植物和受者生存率,促进我国肝移植的发展提供参考。     

冷保存对肝移植术后肝内胆管微循环的影响

目的探讨供肝冷保存对肝移植术后肝内胆管微循环的影响。方法实验大鼠随机分为假手术组（SO组）、供肝冷保存1h组（CP1h组）、供肝冷保存24h组（CP24h组）。采用重建肝动脉的大鼠肝移植模型。在肝移植术后的不同时间点,观察肝内胆管组织损伤程度;经肝动脉注入微球,光镜下行肝组织汇管区内微球计数;采用间接免疫荧光双染技术检测肝组织汇管区微小血管内皮细胞eNOS、El＂-1和ICAM-1的表达,并采用原位杂交技术检测其mRNA的表达。结果冷保存再灌注可引起肝内胆管结构改变,冷保存时间越长损害程度越重。冷保存再灌注可引起肝组织汇管区内微球数量增加,且时间越长微球数量增加越明显。冷保存再灌注可引起汇管区微小血管内皮细胞eNOS蛋白及mRNA表达水平降低,而ET-1和ICAM-1的蛋白及mRNA表达水平升高。结论冷保存可引起大鼠移植肝脏肝内胆管微循环及其内皮细胞功能明显改变,微循环障碍可能在肝内胆管冷保存再灌注损伤中起重要作用。     

大鼠肝脏保存中不同器官保存液对肝细胞凋亡的影响

目的 研究３种目前国内常用的器官保存液对供肝细胞凋亡的影响。方法 分别用ＵＷ液、ＨＣ－Ａ液和ＷＭＯ－１号液灌洗并保存大鼠肝脏,于保存后０、１２、２４ｈ用原位末端标记法检测供肝细胞凋亡情况,并将保存２４ｈ的肝及行大鼠原位全肝移植,观察受者的３ｄ存活率。结果 ３种保存液保存的肝脏均在保存１２ｈ时出现细胞凋亡,ＨＣ－Ａ液级瑟ＷＭＯ－１号液组的凋亡指数（ＡＩ）高于ＵＷ液组（Ｐ〈０．００１）,而ＨＣ－Ａ液组     

自制多器官保存液对大鼠肝脏保存的效果

目的 探讨自制多器官保存液(self-designed multi-organ preservation solution,SMO)对大鼠肝脏低温保存的效果.方法 使用SMO液、UW液和肾脏保存液保存大鼠肝脏6、12和24 h后进行肝移植,观察移植后12 h肝功能改变和移植后14 d大鼠存活情况.结果 SMO液保存24 h之内,肝脏的形态学观测无明显改变.SMO液组与UW液组TB、ALT和血清透明质酸同步升高;肾脏保存液组显著升高,与SMO液组比较差异有统计学意义(F=49.027,70.280,34.349,71.532,446.544,303.408,P＜0.05).SMO液组肝移植后14 d大鼠存活情况良好.结论 大鼠原位肝移植模型证实,SMO液与UW液在保护肝脏功能方面作用相当,优于肾脏保存液.     

Hypothermic continuous machine perfusion improves metabolic preservation and functional recovery in heart grafts

The number of heart transplants is decreasing due to organ shortage, yet the donor pool could be enlarged by improving graft preservation. Hypothermic machine perfusion (MP) has been shown to improve kidney, liver, or lung graft preservation. Sixteen pig hearts were recovered following cardioplegia and randomized to two different groups of 4‐hour preservation using either static cold storage (CS) or MP (Modified LifePort© System, Organ Recovery Systems©, Itasca, Il). The grafts then underwent reperfusion on a Langendorff for 60 min. Energetic metabolism was quantified at baseline, postpreservation, and postreperfusion by measuring lactate and high‐energy phosphates. The contractility index (CI) was assessed both in vivo prior to cardioplegia and during reperfusion. Following reperfusion, the hearts preserved using CS exhibited higher lactate levels (56.63 ± 23.57 vs. 11.25 ± 3.92 μmol/g; P < 0.001), increased adenosine monophosphate/adenosine triphosphate (AMP/ATP) ratio (0.4 ± 0.23 vs. 0.04 ± 0.04; P < 0.001), and lower phosphocreatine/creatine (PCr/Cr) ratio (33.5 ± 12.6 vs. 55.3 ± 5.8; P <0.001). Coronary flow was similar in both groups during reperfusion (107 ± 9 vs. 125 + /‐9 ml/100 g/min heart; P = ns). CI decreased in the CS group, yet being well‐preserved in the MP group. Compared with CS, MP resulted in improved preservation of the energy state and more successful functional recovery of heart graft.     

Role of oxygen during hypothermic machine perfusion preservation of the liver

Grafts from non‐heart‐beating donors are thought to be best preserved by hypothermic machine perfusion (HMP). Controversy exists concerning the role of oxygenation during HMP. In this study, we wanted to evaluate the relative role of oxygenation for graft integrity during and after HMP. Cardiac arrest was induced in male Wistar rats (250–300 g) by phrenotomy. Thirty minutes later, livers were flushed via the portal vein and subjected to 18 h of HMP at 5 ml/min at 4 °C. During HMP, the preservation solution was equilibrated with 100% oxygen (HMP100), with air (HMP20) or not oxygenated at all (HMP0). Graft integrity was assessed thereafter upon warm reperfusion in vitro. During preservation, oxygenation of the perfusate reduced alanine aminotransferase release by 50% compared with HMP0. HMP100 resulted in reduced oxygen free radical‐mediated lipid peroxidation upon warm reperfusion compared with both HMP20 and HMP0. One hundred per cent oxygenation during HMP also significantly enhanced the activation of AMPK salvage pathway, and upstream activation of protein kinase A when compared with HMP0. Enzyme release during reperfusion was reduced by approximately 40% (HMP20) or approximately 70% (HMP100) after oxygenation compared with HMP0. Functional recovery (bile production) was only enhanced by HMP100 (approximately twofold increase vs. HMP20 and HMP0, P < 0.05). Efficiency of HMP might be markedly increased by additional aeration of the perfusate, most successfully by equilibration with 100% oxygen.     

Advantages of Celsior solution in graft preservation from non-heart-beating donors in a canine liver transplantation model.

BACKGROUND: The optimal method for preserving livers from non-heart-beating donors (NHBD) is still unknown. We compared the Celsior solution, a new extracellular-type, low-potassium, low-viscosity preservation solution, with the University of Wisconsin (UW) solution in a canine orthotopic liver transplantation from NHBD. MATERIALS AND METHODS: Fourteen adult mongrel dogs, weighing 9 to 17 kg, were divided into two groups: the Celsior or the UW group (n = 7 each). The thoracic descending aorta and supradiaphragmatic inferior vena cava were cross-clamped for 20 min to induce warm ischemia as a NHBD model. The liver was flushed with the respective cold preservation solution and then stored at 4 degrees C for 4 h. The grafts were transplanted using the piggy-back technique under portal decompression by leaving the native right lobe as a temporary shunt. RESULTS: The duration of liver flushing out (min) was shorter (P < 0.05), and the serum glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, lactate dehydrogenase, lactate, and alpha-glutathione S-transferase concentrations 2 and 6 h after reperfusion of the graft (RPF) were lower (P < 0.05) in the Celsior group than in the UW group. Hepatic tissue blood flow (HTBF) did not deteriorate as much (P < 0.05) in the Celsior group. The serum endothelin-1 level was lower (P < 0.05) in the Celsior group 2 h after RPF. Histopathology of liver specimens revealed portal congestion and hepatocyte necrosis with neutrophil infiltration in the UW group, while these findings were mild in the Celsior group. CONCLUSIONS: The Celsior solution improves vascular endothelial injury in livers from NHBDs and may have advantages in graft flush and preservation of grafts from NHBDs.     

超冷器官保存技术及应用

在器官移植手术中, 器官保存的主要目的是保持离体器官内部组织细胞的活性, 为器官转运及分配、受者术前评估以及手术团队准备赢得时间。器官保存的主要方法可分为常温机械灌注保存和低温保存。其中低温保存是目前临床上最为常用的器官保存方法, 但在低温保存状态下, 组织细胞内部仍存在代谢活动, 这导致器官的长时间保存极为困难。超冷器官保存技术是一种新型的低温器官保存技术, 极大地延长了器官的保存时间, 未来有望成为器官保存的重要手段, 为“器官库”的建立提供技术支持。     

Cold flush after dynamic liver preservation protects against ischemic changes upon reperfusion – an experimental study

Ex vivo machine perfusion of the liver after cold storage has found to be most effective if combined with controlled oxygenated rewarming up to (sub)‐normothermia. On disconnection of the warm graft from the machine, most surgeons usually perform a cold flush of the organ as protection against the second warm ischemia incurred upon implantation. Experimental evidence, however, is lacking and protective effect of deep hypothermia has been challenged for limited periods of liver ischemia in other models. A first systematic test was carried out on porcine livers, excised 30 min after cardiac arrest, subjected to 18 h of cold storage in UW and then machine perfused for 90 min with Aqix‐RSI solution. During machine perfusion, livers were gradually rewarmed up to 20 °C. One group (n = 6) was then reflushed with 4 °C cold Belzer UW solution whereas the second group (n = 6) remained without cold flush. All livers were exposed to 45 min warm ischemia at room temperature to simulate the surgical implantation period. Organ function was evaluated in an established reperfusion model using diluted autologous blood. Cold reflush after disconnection from the machine resulted in a significant increase in bile production upon blood reperfusion, along with a significant reduction in transaminases release alanine aminotransferase and of the intramitochondrial enzyme glutamate dehydrogenase. Interestingly, free radical‐mediated lipid peroxidation was also found significantly lower after cold reflush. No differences between the groups could be evidenced concerning histological injury and recovery of hepatic energy metabolism (tissue content of adenosine triphosphate). Post‐machine preservation cold reflush seems to be beneficial in this particular setting, even if the organs are warmed up only to 20 °C, without notion of adverse effects, and should therefore be implemented in the protocol.     

Role of perfusion medium, oxygen and rheology for endoplasmic reticulum stress-induced cell death after hypothermic machine preservation of the liver.

Recently, the endoplasmic reticulum (ER) has been disclosed as subcellular target reactive to ischaemia/reperfusion and possibly influenced by hypothermic machine preservation. Here, the respective role of perfusate, perfusion itself, and the effect of continuous oxygenation to trigger ER-stress in the graft should be investigated. Livers were retrieved 30 min after cardiac arrest of male Wistar rats and preserved by cold storage (CS) in histidine-tryptophan-ketoglutarate (HTK) for 18 h at 4 degrees C. Other organs were subjected to aerobic conditions either by oxygenated machine perfusion with HTK (MP-HTK) or Belzer solution (MP-Belzer) at 4 degrees C or by venous insufflation of gaseous oxygen during cold storage (VSOP). Viability of livers was evaluated upon reperfusion in vitro according to previously validated techniques for 120 min at 37 degrees C. Oxygenation during preservation (MP-HTK, MP-Belzer or VSOP) concordantly improved functional recovery (bile flow, ammonia clearance), reduced parenchymal enzyme leakage and histological signs of necrosis and significantly attenuated mitochondrial induction of apoptosis (cleavage of caspase 9) compared to CS. However, MP with either medium produced about 500% elevated protein expression of CHOP/GADD153, suggesting pro-apoptotic ER-stress responses, paralleled by a significant elevation of caspase-12 enzyme activity compared to CS or VSOP. Although MP also promoted a slight (20%) induction of the cytoprotective ER-protein Bax inhibitor protein (BI-1), prevailing of proapoptotic reactions was seen by increased cleavage of caspase-3 and poly (ADP-Ribase)-polymerase (PARP) in both MP-groups. Endoplasmic stress activation is conjectured a specific side effect of long-term machine preservation irrespective of the medium, actually promoting cellular apoptosis via activation of caspase-12. The simple insufflation of gaseous O2 may be considered a feasible alternative, apparently indifferent to the endoplasmic reticulum.     

Hypothermic Machine Preservation in Human Liver Transplantation: The First Clinical Series

Hypothermic machine perfusion (HMP) is widely used to preserve kidneys for transplantation with improved results over cold storage (CS). To date, successful transplantation of livers preserved with HMP has been reported only in animal models. In this, the first prospective liver HMP study, 20 adults received HMP‐preserved livers and were compared to a matched group transplanted with CS livers. HMP was performed for 3–7 h using centrifugal perfusion with Vasosol^® solution at 4–6°C. There were no cases of primary nonfunction in either group. Early allograft dysfunction rates were 5% in the HMP group versus 25% in controls (p = 0.08). At 12 months, there were two deaths in each group, all unrelated to preservation or graft function. There were no vascular complications in HMP livers. Two biliary complications were observed in HMP livers compared with four in the CS group. Serum injury markers were significantly lower in the HMP group. Mean hospital stay was shorter in the HMP group (10.9 ± 4.7 days vs. 15.3 ± 4.9 days in the CS group, p = 0.006). HMP of donor livers provided safe and reliable preservation in this pilot case‐controlled series. Further multicenter HMP trials are now warranted.     

Machine perfusion organ preservation: Highlights from the American Transplant Congress 2022

The American Transplant Congress 2022, which took place between June 4th and June 8th of 2022, was a hybrid meeting with in-person attendance in Boston-MA and a real-time virtual experience via an online platform. First, we identified abstracts discussing machine perfusion preservation for all organs, a hot topic and approach that may develop into the new gold standard of organ preservation in the near future. A total of 39 abstracts on organ machine preservation were presented at the meeting. Next, we selected abstracts which focus on advances including new approaches to organ preservation, promising biomarkers, ex-situ treatment including cellular therapies, and novel research areas. Here, we summarized the latest developments on machine perfusion preservation in both experimental and clinical studies.