A comparison of some simplified lactobionate preservation solutions with standard UW solution and Eurocollins solution for pancreas preservation.

Fifty-two rat pancreas transplants were performed to investigate which components of the UW solution were essential for successful pancreas preservation. LEW rats were used and the pancreata stored at 4 degrees C for 48 hr after flushing with commercial UW solution (ViaSpan, DuPont Pharmaceuticals) or a number of simplified solutions. Following storage the pancreata were transplanted into syngeneic recipient animals with streptozotocin-induced diabetes mellitus. Graft function was assessed by regular postoperative blood sugar measurements and a glucose tolerance test on the 14th postoperative day. With commercial UW solution, 4 of 9 recipients (44%) showed satisfactory graft function, while only one of 5 pancreata preserved using Eurocollins solution demonstrated satisfactory function. With solution A, in which hydroxyethyl starch and insulin were omitted from the standard UW solution, 3 of 7 recipients (43%) showed satisfactory function. Omission of glutathione, allopurinol, and adenosine from this solution (solution B) gave satisfactory function in 4 of 8 cases (50%). Substitution of raffinose in solution B with an equimolar concentration of glucose (solution C) resulted in acceptable function in 5 of 8 cases (62%). Increasing the raffinose concentration in solution B to 100 mM/L resulted in only 2 of 8 grafts (25%) with adequate function. By contrast, reversing the Na/K concentrations in solution A resulted in 100% (7/7) satisfactory graft function. We conclude that the rat pancreas can be successfully transplanted following 48-hr cold preservation using UW solution and some simplified versions, and that a substantially simplified lactobionate-based solution with a reversed sodium/potassium ratio improved survival.     

Rat liver preservation: II. Combining UW solution with Eurocollins solution or Ringer's lactate abrogates its protective effect

Abstract. The mechanisms by which cold preservation solutions exert their protective effects are only partially understood. The consequences of mixing different solutions, with presumably different modes of action, may be additive and beneficial or may be deleterious. It is commonplace in clinical liver preservation to use Ringer's lactate (RL), Eurocollins (EC), and University of Wisconsin (UW) solution in sequence for washout of blood, precooling, and cold storage of the organ. In this study, 114 Sprague Dawley rats received orthotopic liver transplants that were flushed in various sequences with RL, EC, and UW solutions. One-week animal survival served as the criterion of preservation success. The results demonstrated that liver preservation with UW solution alone is significantly superior ( P < 0. 01) to any combination of RL, EC, and UW solutions and may explain some of the instances of primary nonfunction in clinical liver transplantation.     

A comparison of histidine-lactobionate and UW solution in 48-hour dog liver preservation.

Many modifications of the UW solution have been reported to yield successful results in rat liver preservation and transplantation. One solution used histidine, in combination with lactobionate (HL-I), and gave superior preservation of the rat liver when compared with the UW solution. In this study we have compared the HL-I solution with 90 mM histidine, HL-II solution with 30 mM histidine, and the UW solution in dog liver preservation and transplantation. Dog livers were preserved for 48 hr in one of the three solutions and transplanted. The peak AST and ALT values were highest in livers preserved in HL-I, intermediate in UW solution, and lowest in HL-II. However, there were no significant differences among survival rates (average 5-7 days per group), posttransplant serum concentration of liver enzymes (AST, ALT, LDH, and alk-phos), clotting factors (PT and PTT), bilirubin, and fibrinogen concentration for each group. Dogs were sacrificed or died within 5-7 days due to rejection in nonimmunosuppressed dogs. Also, rat livers were preserved in the HL-II solution or in a solution in which histidine was replaced by isoleucine (IL-I). Isoleucine is an amino acid with a molecular mass similar to that of histidine, but is not as good a hydrogen ion buffer as histidine at the pH used for liver preservation (7.4). The buffer capacity of the IL-I solution was similar to the UW solution, but about one-half as much as the HL-II solution. Rats receiving a liver preserved for 30 hr in HL-II or IL-I were 100% viable. Rats receiving a liver preserved for 40-44 hr in HL-II or IL-I showed less survival (33% and 25%, respectively). This shows that histidine can be effectively replaced by isoleucine in a preservation solution and gives equivalent preservation results. Thus, the mechanism of improvement of liver preservation with histidine is not due to its action as a hydrogen ion buffer. These studies show that, although the HL solutions are superior for preservation of the rat liver, they are not superior to the UW solution for preservation of the dog liver. However, as others have shown in the rat liver transplant model, a simplified UW solution (HL-II) appears effective in dog liver preservation. The dog liver transplant model remains a more appropriate model for testing new preservation solutions prior to initiation of clinical trials.     

HX—3液和UW液保存大鼠肝脏效果的比较

采用大鼠肝脏非循环离体灌注模型比较自制的ＨＸ－３液和ＵＷ液对大鼠肝脏的保存效果。实验结果显示，经ＨＸ－３液原位灌洗并保存４８小时的肝脏肝组织含水量正常，而同等条件下换用ＵＷ液，肝组织的含水量虽无明显变化，但都低于正常值；随着保存时间的延长，两组肝窦内皮细胞死亡率逐渐上升，但在２４小时以内两组肝窥内皮细胞死亡率的差异不显著．     

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.     

A comparison of a new solution combining histidine and lactobionate with UW solution and eurocollins for rat liver preservation

Forty-six rat liver transplants were performed to investigate the effectiveness of a simplified lactobionate solution containing histidine as a buffer (histidine-lactobionate solution) and to compare it with University of Wisconsin solution. This new solution is isoosmotic (320 mOsm/L) and has a higher sodium content and a lower potassium content (Na: 90 mEq/L, K: 45 mEq/L) than standard UW solution. Buffering capacity is increased by adding histidine (90 mM/L) together with KH2PO4 (20 mM/L) and is greater than that of Eurocollins solution or UW solution. Adenosine, insulin, hydroxyethyl starch, and dexamethasone that are included in UW solution are not included in the new solution. The 1-week survival rate of rats transplanted with livers preserved in this solutions at 4 degrees C was 85% (11/13) following 24-hr preservation and 33% (2/6) after 30-hr preservation. By contrast, UW solution gave only a 29% (5/17) survival rate after 24-hr preservation and 0% (0/6) survival after 30-hr preservation, demonstrating that this simplified UW solution with histidine is superior to UW solution in rat liver preservation. No rats (0/4) receiving livers preserved for 24 hr in Eurocollins solution survived. These findings show that the inclusion of histidine as a buffer dramatically improves the effectiveness of lactobionate-based preservation solutions and justify application in a large-animal model and subsequently in clinical liver transplantation.     

Seventy-two-hour preservation of porcine liver by continuous hypothermic perfusion with UW solution in comparison with simple cold storage

Porcine livers preserved for 72 hr using continuous hypothermic perfusion (CHP) were studied in order to compare the effects of CHP on energy metabolism with those of simple cold storage (SCS). The livers of the CHP group were perfused in situ for 72 hr at 7 degrees C with University of Wisconsin (UW) solution and FC-43 as an oxygen carrier, while those of the S1 group were stored ex situ for 48 hr at 4 degrees C in UW solution, and those of the S2 group for 72 hr. They were then recirculated with human blood at 37 degrees C for 2 hr for the evaluation of their viability. At the end of preservation, significantly higher levels of total adenine nucleotides (TAN) and energy charge (EC) were observed in the CHP group compared with the S1 and S2 groups. At 2 hr recirculation, the level of TAN was significantly higher in the CHP group than in the S1 and S2 groups. The EC level was also higher in the CHP group than in the S2 group. During recirculation, the ketone body ratio (acetoacetate/beta-hydroxybutyrate) was higher in the CHP group than in the S2 group. The values in the CHP group were above 1.0 after 45 min recirculation. There were no significant differences in the pyruvate/lactate ratio and lactate level between the CHP and S1 groups. However, these values were significantly different from those in the S2 group. The present findings demonstrate that CHP using UW solution and the oxygen carrier was better able to preserve the energy metabolism of the porcine liver for 72 hr than 48-hr SCS in UW solution.     

UW solution improves duration and quality of clinical liver preservation

Prolonged liver preservation (up to 17 hours) with UW solution had no adverse effect on perioperative blood loss or results of postoperative serum biochemistry studies. After use of this solution, biliary and vascular complications as well as evidence of histologic damage were less. The advantages of the extended preservation time permit liver transplantation to be done as a semi-elective procedure; more patients can be waiting at home instead of near the transplant center. The availability of UW solution also makes it possible to send grafts long distances throughout the nation. Furthermore, surgeons can arrange for backup patients in case the recipient proves to be inoperable. This capability should reduce organ wastage, even before the time limits of preservation with UW solution have been determined definitely. We feel that UW solution undoubtedly has improved both the duration and quality of liver graft preservation.     

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。     

Myocardial preservation with the UW solution. First European results in clinical heart transplantation

In recent years, there is a growing body of evidence that the University of Wisconsin (UW) solution offers many advantages in organ preservation with regard to preservation quality and time. We, therefore, conducted the first European prospective, randomized, clinical trial comparing myocardial performance after preservation with UW and St. Thomas Hospital (ST) solution. Preliminary results indicated superior heart function after preservation with UW solution.     

Verapamil improves rat hepatic preservation with UW solution

Verapamil, a calcium channel blocker, improves myocardial preservation during cold cardioplegia and protects against renal damage during periods of warm and cold ischemia. To determine if verapamil could prevent ischemic damage to livers during and after cold storage, harvested rat livers were flushed with either University of Wisconsin (UW) solution or UW solution with 25 mg/liter verapamil. Twenty rats were used in each group. After 24 hr of storage at 4 degrees C, livers were perfused with oxygenated blood through the portal veins for 2 hr at 37 degrees C and pH 7.4. Liver enzymes, electrolytes, and perfusate flow rate were determined at 30-min intervals. At 90 min of perfusion, the verapamil group of livers had less elevation of AST (110 +/- 17 IU/liter vs 172 +/- 25 IU/liter, P less than 0.05), ALT (115 +/- 21 IU/liter vs 210 +/- 34 IU/liter, P less than 0.05), and LDH (962 +/- 170 IU/liter vs 1452 +/- 253 IU/liter, NS). Verapamil livers produced more bile than controls (6.9 +/- 1.9 microliters/g vs 2.3 +/- 1.7 microliter/g, P less than 0.05) and maintained a higher portal flow rate throughout the perfusion. Both groups showed similar reduction in liver weights after storage (3.9 +/- 0.9% vs 2.8 +/- 0.7%) and required the same amount of bicarbonate for correction of acidosis during perfusion (2.6 +/- 0.2 mM vs 2.8 +/- 0.2 mM). Light microscopic exam after perfusion showed hepatocyte damage in 30% of control livers, but 0% of verapamil livers. We conclude that verapamil-treated rat livers showed less damage and better function upon reperfusion after 24 hr of cold storage. This agent may be clinically useful as an additive to the UW preservation solution for livers.