大鼠肝脏缺血再灌注损伤后5′核苷酸酶和乳酸脱氢酶活性变化的研究

目的探讨大鼠肝脏经过UW、Celsior和HTK三种不同类型保存液低温保存和常温再灌注后5′核苷酸酶和乳酸脱氢酶活性的变化.方法将大鼠肝脏在UW、Celsior和HTK液中低温4℃保存0、8、16和24 h后,采用离体连续灌注模型,用Krebs-Henseleit液37℃连续循环灌注90 min,灌注结束后取肝脏组织标本测定5′核苷酸酶和乳酸脱氢酶活性,并测定胆汁分泌量的变化.结果经过16和24 h的UW和Celsior低温保存后的肝组织5′核苷酸酶和乳酸脱氢酶的活性出现降低;HTK组8 h就出现降低.UW和Celsior组经过24 h的低温保存后,胆汁分泌量开始明显降低;在HTK组16 h后,胆汁分泌量就显著降低.结论 5′核苷酸酶和乳酸脱氢酶的活性随着低温缺血时间的延长逐渐降低;UW和Celsior液对肝窦内皮细胞和肝实质细胞的保护作用均强于HTK.     

大鼠肝脏缺血再灌注损伤后5′核苷酸酶和乳酸脱氢酶活化变化的研究

目的 探讨大鼠肝脏经过UW、Celsior和HTK三种不同类型保存液低浊保存和常温再灌注后5′核苷酸酶和乳酸脱氢酶活性的变化。方法 将大鼠肝脏在UW、Celsior和HTK液中低温4℃保存0、8、16、和24h后,采用离体连续灌注模型,用Krebs-Henseleit液37℃连续循环灌注90min,灌注结束后取肝脏组织标本测定5′核苷酸酶和乳酸脱氢酶活性,并测定胆汁分泌量的变化。结果 经过16和24h的UW和Celsior低温保存后的肝组织5′核式酸酶和乳酸脱氢酶的活性出现降低;HTK组8h就出现降低,UW和Celsior组经过24h的低温保存后,胆汁分泌量开始明显;在HTK组16h后,胆汁分泌量就显著降低。结论 5′核苷酸酶和乳酸脱氢酶的活性随着低温缺血时间的延长逐渐降低;UW和Celsior液以肝窦内皮细胞和肝实质细胞的保护作用均强于HTK。     

不同器官保存液对大鼠肝脏缺血再灌注损伤时嘌呤核苷磷酸酶活性和透明质酸吸收率的影响

目的 探讨大鼠肝脏低温保存及常温缺血再灌注过程中在不同的保存液中嘌呤核苷磷酸酶(PNP)活性和透明质酸(HA)吸收率的变化.方法 将大鼠肝脏在三种不同保存液中低温保存16 h和24 h后,用37℃Krebs-Henseleit液连续循环灌注90 min,分别于不同灌注时间检测灌洗液中PNP活性和外源性透明质酸的吸收率的变化.结果 经过16 h的低温保存后,再灌注60 min前,HTK保存的肝脏中PNP明显高于uw和Celsior;60 min后HTK和Celsior保存的肝脏中PNP明显高于UW;经过24 h的低温保存后,再灌注15 min后,HTK保存的肝脏中PNP明显高于Celsior,而Celsior又明显高于UW.低温保存16 h后,再灌注时,3种保存液保存的肝脏对外源性透明质酸的吸收率均为负值,表明肝窦内皮细胞受到一定程度的损伤;保存24 h者,UW液保存肝脏外源性透明质酸的吸收率明显高于Celsior液和HTK液.结论 随着低温保存和再灌注时间的延长,大鼠肝脏中PNP活性逐渐增高,而外源性透明质酸的吸收率下降;二者可作为评价肝脏缺血再灌注损伤的指标.     

环孢霉素A预处理对大鼠移植肝脏影响的实验研究

目的：研究环孢霉素A（CsA）预处理保存大鼠肝脏对原位移植后的植肝功能影响。方法：将大鼠随机分为A组（对照组，HTK液保存组）和B组（实验组，HTK液＋CsA保存组），两组均保存12h后行原位肝移植，分别于供肝保存0h、12h及植术后7d检测各组血清谷丙转氨酶（AST），谷草转氨酶（AST），乳酸脱氢酶（LDH）浓度及各时间段线粒体呼吸功能RCR及P／O值。通过HE染色及原位凋亡染色观察各组肝脏组织细胞形态学改变及凋亡情况。结果：B组血清ALT、AST、LDH活性于保存12h显著低于A组，B组各时间段RCR及P／O值于保存12h，移植术后0．5h及术后7d均高于A组。细胞形态学检查B组移植肝组织细胞结构改变轻微，凋亡指数于保存12h．术后0．5h均低于A组。结论：CsA预处理供肝主要通过保护线粒体功能减轻冷保存期和再灌注对大鼠供肝的损伤及抑制肝细胞的凋亡，使大鼠原位肝移植后存活率升高。     

冷冻保存大鼠肝脏离体再灌注时嘌呤核苷磷酸酶活性和透明质酸吸收率的变化

目的探讨不同保存液保存大鼠肝脏后离体再灌注时嘌呤核苷磷酸酶(PNP)活性和透明质酸吸收率的变化及意义。方法分别采用UW液、HTK液和Celsior液灌洗、冷保存Wistar大鼠肝脏16及24 h,然后用37℃的Kreb-Henseleit液在常温下连续灌注90 min,分别于灌注0、15、30、60和90 min时,从灌注液中取样,测定嘌呤核苷磷酸酶活性和外源性透明质酸吸收率的变化,据此评价肝窦内皮细胞的状况。结果经过16 h的低温保存,在再灌注60 min以前,HTK液组灌注液中PNP的含量明显高于UW液组和Celsior液组(P<0.01);再灌注60 min后,HTK液组和Celsior液组灌注液中PNP的含量明显高于UW液组(P<0.01)。经过24 h的低温保存,在再灌注15 min后,HTK液组灌注液中PNP含量明显高于Celsior液组(P<0.01),而Celsior液组又明显高于UW液组(P<0.01)。透明质酸的吸收率均为负值,说明内源性透明质酸的释放大于外源性透明质酸的吸收,且随着保存时间和再灌注时间的延长,这一趋势更加明显,其中HTK液组最明显,Celsior液组次之。结论随着低温保存和再灌注时间的延长,肝脏中PNP活性逐渐升高,外源性透明质酸的吸收率下降,二者可作为评价肝脏缺血-再灌注损伤的指标。     

腺苷A2受体激动剂对大鼠肝脏缺血再灌注损伤时细胞凋亡的影响

目的:研究腺苷A2受体激动剂对大鼠缺血再灌注损伤（I/R）时肝细胞凋亡的影响。方法:通过门静脉插管，分别用60 mL 4℃ HTK保存液和含有腺苷A2受体激动剂CGS21680（30 μg/100 mL）HTK保存液灌注大鼠肝脏, 然后切取肝脏4℃ HTK液中保存24h，Krebs-Henseleit缓冲液常温连续再灌注45 min。检测灌注期间丙氨酸氨基转移酶（ALT）和谷氨酸乳酸脱氢酶(GLDH)及门静脉压力（PVP）的变化。灌注结束时检测灌洗液中细胞凋亡、脂质过氧化物（LPO）和胆汁分泌量的变化。结果:与对照组相比, CGS21680组大鼠灌注液中ALT，GLDH 和PVP明显降低(均P<0.01)， 胆汁分泌量明显增加 (P<0.01), LPO含量明显降低(P<0.05)，细胞凋亡明显减少(P<0.05)。结论:腺苷A2受体激动剂可减轻离体大鼠肝脏I/R损伤和细胞凋亡的发生率，其作用机制可能与氧自由基的减少有关。     

Celsior液与UW液对无心跳大鼠供肝保存效果的比较

目的 比较Celsior(CS)液与UW液对大鼠无心跳供者(NHBD)供肝的保存效果.方法 选取健康雄性SD大鼠作为肝移植的供、受者.通过阻断大鼠主动脉和膈上下腔静脉10 min的方法,制备和获取NHBD供肝,并采用不同的器官保存液灌注和冷保存供肝.随机将受者分为4组.CS8 h组:受者采用经CS液灌注和冷保存8 h的供肝移植;UW8 h组:受者采用经UW液灌注和冷保存8 h的供肝移植;CS16 h组:受者采用经CS液灌注和冷保存16 h的供肝移植;UW16 h组:受者采用经UW液灌注和冷保存16 h的供肝移植.受者门静脉开放前、开放后1、3及6 h,取各组受者的静脉血检测血清丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)、内皮素1(ET-1)、白细胞介素1(IL-1)及肿瘤坏死因子α(TNF-α)水平;观察和比较各组受者的胆汁生成量、移植肝组织病理学改变及术后7 d内的存活率.结果 NHBD供肝经UW液灌注后呈"花斑"状,肝叶边缘灌注不良,经CS液灌注后肝叶边缘灌注良好.CS8 h组和UW8 h组受者的胆汁生成量分别为(0.21±0.01)ml和(0.10±0.02)ml(P<0.05).门静脉开放后1、3及6 h,CS8 h组受者的血清ALT及AST水平明显低于UW8 h组(P<0.05),门静脉开放后1、3h,CS8 h组受者的血清ET-1、IL-1及TNF-α水平均明显低于UW8 h组(P<0.05);CS8 h组受者移植肝肝窦扩张、门静脉充血及炎症细胞浸润等病理学改变明显轻于UW8 h组,CS8 h组和UW8 h组受者术后7 d的存活率分别为58.3%和25.0%(P<0.05).CS16 h组和UW16 h组受者各时点的胆汁分泌量、血清ALT、AST、ET-1、IL-1及TNF-α水平的比较,差异均无统计学意义(P>0.05),两组受者均在术后3 d内死亡,两组受者移植肝组织病理学改变无明显差异.结论 CS液对大鼠NHBD供肝的保存效果优于UW液,这可能与UW液较CS液粘稠及CS液能够减少枯否细胞的激活有关;NHBD供肝的冷保存时间不宜超过16 h.     

肝移植供肝的保存

保持供体器官离体后的活力,对于移植后器官迅速恢复功能和存活是十分重要的.迄今为止,肝移植供肝的静态低温保存仍是普遍采用的方法.虽然这种方法简单而且有效,但是随着供体老年化、边缘化和心跳停止供肝数量的增加,导致供肝的质量日益恶化,静态低温保存能否继续保持供肝活力令人怀疑.本综述介绍供肝保存及器官保存液的发展历史及最新进展,包括低温机器灌注.尽管低温机器灌注可能优于静态低温保存,但是供肝仍然存在低温相关损伤.因此,最近已有科研机构开始重视常温机器灌注的研究,并有望成为肝脏移植保存的新方法.     

不同器官保存液对大鼠肝脏透明质酸吸收率的影响

目的　探讨不同器官保存液对大鼠肝脏透明质酸吸收率的影响 ,以评价它们对肝窦内皮细胞的保护作用。方法　大鼠肝脏原位灌洗后 ,分别在UW液、Celsior液或Histidine Tryptopan Ketoglutarate液 (HTK液 )中低温保存 16和 2 4h ,然后用含透明质酸的Kreb Henseleit液在 37℃下连续循环灌注 90min ,分别于灌注 0、15、30、6 0和 90min时检测肝脏对外源性透明质酸的吸收率。结果　低温保存 16h ,再灌注 0、15、30、6 0和 90min时 ,3种保存液保存的肝脏对外源性透明质酸的吸收率均为负值 ,表明肝窦内皮细胞受到一定程度的损伤 ,但UW液和Celsior液对肝窦内皮细胞的保护作用较HTK液为优 (P <0 .0 1) ;保存 2 4h者 ,UW液对肝窦内皮细胞的保护作用优于Celsior液和HTK液。结论　UW液对肝窦内皮细胞具有较强的保护作用     

心脏停跳大鼠肝脏过氧化亚硝酸介导的细胞凋亡变化

目的 该实验旨在研究过氧化亚硝酸对心脏停跳大鼠肝细胞凋亡的影响.方法 切取雄性Wistar大鼠肝脏后,通过门静脉插管灌注60 ml 4℃HTK保存液,其中心脏搏动组为立即插管;心脏停跳组为60 min后插管;另外一组为心脏停跳但灌注液中含有7500 IU超氧化物歧化酶(SOD).(n均=6).然后所有的大鼠肝脏均在4℃HTK液中保存24 h后置于循环灌注系统中,用Kreb-Henseleit缓冲液常温再灌注45 min.结果 同心脏停跳组相比,心脏搏动和SOD组大鼠灌注液中转氨酶(GPT和GLDH)的含量明显减少(均P<0.05);门静脉压力明显降低(均P<0.01);胆汁分泌量明显增加(均P<0.01),一氧化氮含量明显降低(均P<0.05);细胞凋亡明显减少(均P<0.05);灌洗液中硝基酪氨酸明显减少(P<0.01和P<0.05)且硝基酪氨酸免疫组化染色明显减弱.结论 氧自由基的代谢产物--过氧化亚硝酸与心脏停跳大鼠肝脏细胞凋亡的发生相关.     

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

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

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.     

Advantages of normothermic perfusion over cold storage in liver preservation

BACKGROUND: To minimize the ischemia-reperfusion injury that occurs to the liver with the current method of preservation and transplantation, we have used an extracorporeal circuit to preserve the liver with normothermic, oxygenated, sanguineous perfusion. In this study, we directly compared preservation by the standard method of simple cold storage in University of Wisconsin (UW) solution with preservation by perfusion. METHODS: Porcine livers were harvested from large white sows weighing between 30 and 50 kg by the standard procedure for human retrieval. The livers were preserved for 24 hr by either cold storage in UW solution (n=5) or by perfusion with oxygenated autologous blood at body temperature (n=5). The extracorporeal circuit used included a centrifugal pump, heat exchanger, and oxygenator. Both groups were then tested on the circuit for a 24 hr reperfusion phase, analyzing synthetic function, metabolic capacity, hemodynamics, markers of hepatocyte and reperfusion injury, and histology. RESULTS: Livers preserved with normothermic perfusion were significantly superior (P=0.05) to cold-stored livers in terms of bile production, factor V production, glucose metabolism, and galactose clearance. Cold-stored livers showed significantly higher levels of hepatocellular enzymes in the perfusate and were found to have significantly more damage by a blinded histological scoring system. CONCLUSIONS: Normothermic sanguineous oxygenated perfusion is a superior method of preservation compared with simple cold storage in UW solution. In addition, perfusion allows the possibility to assess viability of the graft before transplantation.     

Preservation of pig liver allografts after warm ischemia: normothermic perfusion versus cold storage

Warm ischemia is known to induce substantial damage to the liver parenchyma. With respect to clinical liver transplantation, the tolerance of the liver to warm ischemia and the preservation of these organs have not been studied in detail. In isolated reperfused pig livers we proceeded according to the following concept: Livers were subjected to 1 or 3 h of warm ischemia. Subsequently, these organs were preserved by either normothermic perfusion or cold storage (histidine-tryptophan-α-ketoglutarate, HTK) for 3 h each. After storage, liver function was assessed in a reperfusion circuit for another 3 h. Parameters under evaluation were bile flow, perfusion flow, oxygen consumption, enzyme release into the perfusate (creatine kinase, glutamic oxaloacetic transaminase (GOT), lactic dehydrogenase, and glutamic pyruvic transaminase), and histomorphology. Damage to the liver was lowest after warm ischemia of 1 h. The results after cold storage were superior to those after normothermic perfusion (GOT: 3.2±0.3 and 2.6±0.2 U/g liver; cumulative bile production: 14.7±2.1 and 9.4±1 ml, respectively;P<0.05). In contrast, we found substantial damage at the end of reperfusion in livers undergoing 3 h of warm ischemia under both preservation techniques with severe hepatocellular pyknoses and essentially altered nonparenchymal cells. The results suggest that pig livers undergoing 1 h of warm ischemia and cold storage for 3 h with HTK solution may lead to functioning after transplantation.     

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.     

Liver preservation with HTK: salutary effect of hypothermic aerobiosis by either gaseous oxygen or machine perfusion

The aim of the present study was to improve the viability of marginal livers from non-heart beating donors upon cold preservation using two different techniques for the provision of tissue aerobiosis. Livers from male Wistar rats (250-300 g bw) were harvested after 60 min of cardiac arrest, flushed via the portal vein with 20 mL of heparinized Ringer's solution and 60 mL of histidine-tryptophan-ketoglutarate (HTK) preservation solution. Control livers were then stored submerged in HTK for 24 h at 4 degrees C while other organs were subjected to aerobic conditions by either insufflation of gaseous oxygen via the venous vascular system of the cold stored organ (VSOP) or pulsatile machine perfusion (MP) with oxygenated HTK at 5 mL/min at 4 degrees C. Superoxide dismutase (SOD) (7500 IU) was added to the last 10 mL of HTK in order to prevent adverse effects of high oxygen tensions at hypothermia. Viability of the livers was assessed upon isolated perfusion in vitro with oxygenated Krebs-Henseleit buffer at constant flow. VSOP or MP, both significantly improved vascular conductivity upon reperfusion as evaluated by portal venous pressure, reduced hepatic enzyme release and led to a rise in hepatic bile production upon reperfusion. Induction of apoptosis was also looked for in tissue homogenates by Western analysis for cleavage of poly(ADP-ribose)polymerase (PARP). Expression of cleaved PARP fragment could be found in reperfused control livers but also, though to a lesser extend, after VSOP or MP. In conclusion, provision of oxygen during cold preservation significantly contributes to improve organ viability upon reperfusion and must be regarded as a useful adjunct for marginal or pre-damaged livers. HTK has been shown for the first time to be also suitable for long-term MP preservation of the liver, but, as inferred from these data, simple insufflation of gaseous O2 may be considered a feasible alternative.     

Protective effects of ambroxol in hypothermic liver preservation: a transplant study.

The bronchosecretolytic agent ambroxol added to histidine-tryptophan-ketoglutarate (HTK) solution has recently been shown to protect cold stored rat hepatocytes. The aim of the present study was to confirm these observations in a rat liver transplantation model. Before orthotopic liver transplantation, donor livers from 30 syngeneic Wistar rats were assigned to three groups (n = 10): (A) in situ flush (ISF) and 1/2-h cold storage (CS) with HTK solution, (B) ISF and 3-h CS with HTK, and (C) ISF and 3-h CS with HTK + 10(-3) mol/L ambroxol. The efficacy of the drug was evaluated by postoperative survival (> 14 days) and liver enzyme release (ALT), bile flow, histomorphological injury, and malondialdehyde (MDA) level in the grafts 15 min after reperfusion. After 1/2-h CS with HTK solution (A), 90% of the transplanted rats survived. In comparison with donor conditions, bile flow in the reperfused grafts decreased to 87 +/- 5.3%, whereas postoperative ALT levels slightly increased. After 3-h HTK preservation (B), the survival rate decreased to 60%, while ALT values markedly increased and bile flow after reperfusion declined to 82 +/- 6.6%. Ambroxol added to HTK solution (C) enhanced bile flow to 106 +/- 3.4%(p < .05), and reduced ALT and MDA levels and histomorphological injury of the transplanted livers, so that its beneficial effect in organ preservation has been confirmed in the transplant model. However, survival rate was not improved by the agent, probably because of the low cold ischemia tolerance of the Wistar rat livers used.     

Comparison of HTK- and UW-solution for liver preservation tested in an orthotopic liver transplantation model in the pig

The aim of this experimental study was to compare the preservation potency of University of Wisconsin (UW) and HTK (Bretschneider) solutions in an orthotopic liver transplantation (OLT) model in pigs. Livers were harvested using an in situ perfusion technique, where organs were flushed with the solution being tested, stored on ice — cold storage (CS) — for 2 or 24 h and then transplanted. Parameters monitored were liver enzymes in serum, hepatic water content, high energy phosphates, nuclear magnetic resonance (NMR) relaxation time T2, light microscopy and bile production. CS for 24 h is an extreme in pig liver preservation and is not compatible with animal survival. Biopsies showed drastic morphological changes and grafts did not produce bile in either group. (Bile production 2 h CS: HTK, 5.6 ± 1.8 ml/h; UW, 4.7 ± 2.3 ml/h) Enzyme release after reperfusion (ASGOT, ?LDH) was higher in long-term preservation. Hepatic tissue water content significantly decreased during CS in UW preserved livers. Edema alter reperfusion (?H₂0: HTK 24 h = + 5.6%, UW 24 h= + 4.8%) and regeneration capacity after reperfusion (UW 2 h = 63%, HTK 2 h = 55%, UW 24 h = 30%, HTK 24 h = 30%) were not significantly different. However, we did not observe major differences in preservation potency between the solutions tested. Differences were correlated, rather, with length 9 time of CS, than with the solution used. Therefore, HTK solution seemed to be a low potassium containing alternative to UW solution.     

Fibrinolytic preflush upon liver retrieval from non-heart beating donors to enhance postpreservation viability and energetic recovery upon reperfusion.

BACKGROUND: Our objective was to evaluate graft equilibration with high viscosity (University of Wisconsin solution [UW]) or low viscosity (Bretschneider's histidine-tryptophan-ketoglutarate [HTK]) during liver procurement from non-heart beating donors (NHBD) and the potential impact of a preceding fibrinolysis with streptokinase on postpreservation viability. METHODS: After 60 min of cardiac arrest, rat livers were perfused by gravity (60 cm H2O) via the portal vein with either 60 ml of HTK, 20 ml of UW, or 20 ml of Ringer's solution (22 degrees C including 7500U of streptokinase) and, subsequently, 20 ml of UW. After 24 h of storage at 4 degrees C, viability of the livers was assessed upon isolated reperfusion in vitro. RESULTS: Magnetic resonance imaging revealed severe perfusion deficits, which were mildly attenuated with HTK, upon flush-out with UW. After preflush with streptokinase, a mostly homogenous distribution of the preservation solution was observed throughout the liver tissue. The choice of the flush-out solution (UW or HTK) had no influence on parenchymal enzyme leakage, hepatic bile production, or tissue levels of ATP after reperfusion of the livers. Fibrinolytic preflush, however, resulted in a relevant and significant improvement of structural integrity as well as functional and metabolic recovery. CONCLUSIONS: Compromised vascular tissue perfusion upon organ harvest in NHBD triggers graft dysfunction after cold storage and can easily be circumvented by temporary fibrinolysis before graft retrieval.     

Optimising post-conditioning time of marginal donor livers

Background Due to the discrepancy between organ donors and receptors, the use of marginal livers (e.g., non-heart-beating-donor grafts) for transplantation purpose increased. The potential of a short-term aerobic machine perfusion (post-conditioning) for “less than optimal” grafts after cold storage (CS) was recently demonstrated. In our study, the optimal time course of post-conditioning (PC) is to be evaluated. Materials and methods Livers from male Wistar rats were withdrawn 30 min after cardiac arrest and flushed with histidine tryptophan ketoglutarate (HTK) solution. Then they were stored in HTK at 4°C for 18 h. After 16 h, some livers were put on PC by cold perfusion with HTK for 0.5, 1, 2 or 3 h. Afterwards, the viability of the organs was estimated by warm reperfusion (2 h) in vitro. Results After 1 h of PC, a significant increase in bile production and a decrease in enzyme release could be detected in comparison to CS. The adenosine triphosphate content of the PC livers after 1 h of treatment was significant higher than in CS organs. No markers for apoptosis could be detected after 1 h PC. Conclusion It can be concluded that a PC of 1 h after cold storage can ameliorate the organ viability of marginal livers. The extension or abbreviation of PC time seems to have no further beneficial effects. German Society of Surgery, Surgical Forum 2008, Best of Abstracts