Comparison of histidine-tryptophan ketoglutarate and University of Wisconsin solutions as primary preservation in renal allografts undergoing pulsatile perfusion

INTRODUCTION: University of Wisconsin (UW) solution is the standard preservation solution for organ transplantation. Histidine-tryptophan ketogluatarate (HTK) solution has been used increasingly for kidney, pancreas, and liver transplantation. This study compared HTK and UW used during kidney procurement with subsequent pulsatile perfusion. METHODS: Between January and October 2003, 91 deceased renal and simultaneous kidney pancreas transplants were performed (UW, n = 41, and HTK, n = 50). There were no differences with regard to donor and recipient demographics or cold ischemia. RESULTS: Delayed graft function occurred in 3 (7%) of UW and 4 (8%) of HTK-preserved kidneys (P = NS). There were no significant differences between patient or graft survival. There was an anticipated difference between total preservative volumes used (HTK: 4.1 +/- 1.0 vs UW: 3.0 +/- 0.5; P < .005). CONCLUSION: UW and HTK appear to have similar efficacy in kidney preservation with pulsatile perfusion. HTK preservation solution can be used safely in conjunction with pulsatile preservation for cold storage of renal allografts.     

Initial experience using histidine-tryptophan-ketoglutarate solution in clinical pancreas transplantation

BACKGROUND: The colloid-based University of Wisconsin (UW) preservation solution has been used extensively in clinical pancreas transplantation. Experimental studies support the use of the crystalloid-based histidine-tryptophan-ketoglutarate (HTK) preservation solution for this purpose. AIM: We report our initial experience with HTK for pancreas allograft preservation and compare this to a contemporary experience with UW solution in conventional multiorgan deceased donors (<50 yr). MATERIALS AND METHODS: Retrospectively collected information on 33 pancreas transplants between September 2001 and October 2002 were analyzed for early graft function and complications up to 30 d after procurement and storage in either HTK or UW solutions. During multi-organ recovery, either UW solution (4-5 L) or HTK solution (8-10 L) was used for aortic perfusion and subsequent back-table flush and storage. Exocrine drainage of 31 pancreas allografts was enteric, while the bladder was used for drainage in two cases. Patient outcomes were analyzed according to the preservation solution used. Sixteen pancreata were used in combination with a kidney allograft (SPK), seven were used in patients after prior kidney transplantation (PAK), while 10 were used in patients who were not in renal failure (PTA). RESULTS: The UW group consisted of 17 patients (10 SPK, three PAK, four PTA) with a mean donor age of 29.5 +/- 10.7, and a mean cold ischemia time of 15.1 +/- 2.1 h. The mean post-transplant pancreas and kidney function on days 1 and 10 were amylase (315 and 99 IU/L), lipase (1727 and 346 IU/L), glucose (121 and 100 mg/dL) and creatinine (5.01 and 1.77 mg/dL). Patient and graft survival was 100% at 1-month post transplant. In the HTK group there were 16 patients (six SPK, four PAK, six PTA) with a mean donor age 21.9 +/- 5.7 and a mean cold ischemia time 14.0 +/- 1.3 h. The mean post-transplant pancreas and kidney function on days 1 and 10 were amylase (588 and 126 IU/L), lipase (4711 and 441 IU/L), glucose (97 and 109 mg/dL) and creatinine (5.28 and 2.42 mg/dL). Patient survival was 100% while graft survival was 94% at 1-month post-transplant. CONCLUSIONS: Early graft function and complications are comparable with HTK and UW solutions for pancreas allograft preservation.     

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.     

Comparison of Preservation Solutions for Washout of Kidney Grafts: An Experimental Study

Objective

The impact of different preservation solutions for washout of kidney grafts was evaluated regarding temperature, kidney weight, remaining red blood cells (RBCs) and histological evaluation after ex vivo washout using 500 mL cold preservation solution at 4°C followed by 24 hours cold storage (CS).

Methods

Kidneys retrieved from Landrace pigs (20–30 kg) were immediately washed (warm ischemic time 0 min [WIT 0]), using 500 mL cold University of Wisconsin solution (UW), histidine-tryptophan-ketoglutarate (HTK), or Polysol (PS) followed by 24 hours, CS. Also, kidneys were retrieved after a WIT of 30 minutes followed by washout using HTK or PS.

Results

After washout, the weight of kidneys washed out with HTK had increased, whereas that of organs in the UW or PS group had decreased. After washout with UW, the core temperature of WIT 0 kidneys was lower than that with HTK. The time needed for washout using 500 mL solution was shorter using PS compared with HTK for both WIT 0 and WIT 30 groups. The amount of remaining RBCs was similar between all WIT 0 groups; whereas in the WIT 30 groups the amount was higher in kidneys washed out using HTK compared with PS. Histological evaluation showed less tissue injury among PS-washed kidneys compared with UW or HTK.

Conclusion

Overall, kidneys washed-out with PS showed better preservation of structural integrity after 24 hours, CS compared with either UW or HTK. Washout of warm ischemically damaged kidneys was more effective using PS compared with HTK.     

Eurotransplant randomized multicenter kidney graft preservation study comparing HTK with UW and Euro-Collins

The aim was to evaluate the effect of HTK compared to UW and Euro-Collins (EC) on the initial graft function and long term graft survival in two prospective randomized studies. Only kidneys from heart-beating, kidney-only or kidney + heart donors were eligible for entry. Initial non-function (INF) was defined as the absence of life-sustaining renal function, requiring dialysis treatment on two or more occasions, during the first week after transplantation. To evaluate the contribution of the preservation solutions on INF in relation to other factors, a multivariate, 2-step logistic regression model was used. Randomization was performed between July 1990 and September 1992. The UW-HTK study comprised 342 donors and 611 transplants (UW: 168 donors and 297 transplants, HTK: 174 donors and 314 transplants). In the EC-HTK study 317 donors and 569 transplants were included (EC: 155 donors and 277 transplants, HTK: 162 donors and 292 transplants). INF occurred in 33 % of either HTK-(n = 105) or UW-(n = 99) preserved kidneys (P = NS), and in 29 % of the HTK-(n = 85) and in 43 % of the EC-(n = 119) preserved kidneys (P = 0.001). Multivariate analysis showed no significant influence of the preservation solution on the incidence of INF in the UW-HTK study, but factors contributing to INF were donor age, cause of death, retransplantation, and cold ischemic period. The EC-HTK study showed a significantly higher risk of INF, using EC as preservation, in addition to cold ischemic period and donor quality. The 3-year graft survival of HTK-preserved kidneys was 73 %, compared to 68 % for UW-preserved kidneys in the UW-HTK study (P = NS); while the 3-year graft survival of HTK preserved kidneys was 70 % compared to 67 % for EC-preserved kidneys in the EC-HTK study (P = NS). We can conclude that HTK is comparable to UW in its preservative abilities, using kidneys from heart-beating kidney-only donors, whereas EC as renal preservation solution should be avoided. Received: 2 November 1998 Received after revision: 10 August 1999 Accepted: 16 September 1999     

Evaluation of cysteine effect on redox potential of porcine liver preserved by simple hypothermia

Introduction

Cysteine (cys), a thiol amino-acid, is involved in de novo glutathione (GSH) synthesis in the extra- and intracellular space. It is also probably involved in the anaerobic glycolysis process. Both these facts may affect the metabolic condition of the liver preserved by simple hypothermia for transplantation. The aim of the study was to verify whether cysteine addition to histidine-tryptophan-ketoglutarate (HTK) organ preservation solution showed a positive effect on liver redox potential after 12-hour preservation in simple hypothermia.

Materials and methods

After collecting livers of Great White breed pigs that underwent 30 min of warm ischemia, before 30-min perfusion and cooling to 4°C with modified HTK solution containing cysteine prior to 12 h of preservation. Activity of glutathione reductase (GR), glutathione peroxidase (GPx), and superoxide dismutase (SOD) was determined in liver homogenates after perfusion and after the preservation period. The results were compared with pure HTK, Ringer's and reference University of Wisconsin (UW) solutions.

Results

30 min of perfusion and 12 h of cold preservation (CIT) in the Ringer's solution markedly increased GPx, SOD, and GR activities in liver homogenates compared with the activity using other fluids. After 12-h CIT the activities of GR, GPx and SOD were significantly higher in cys-modified HTK solution than the control HTK solution. They were comparable to the values recorded for the UW group.

Conclusions

Addition of cys to the HTK solution positively influenced the total pool of free radical scavengers in a liver undergoing 12-hour ischemia in the simple hypothermia, which was reflected in the elevated redox enzyme activity possibly due to cys participation in GSH synthesis.     

Evaluation of a novel cold storage solution (HBs) in a rat kidney transplant model.

We developed an improved solution for hypothermic storage (0-4 degrees C) of kidneys. The cold storage solution (HBS) was composed of macromolecules, high-energy cellular substrates, and a mixture of antiproteolytic amino acids, antioxidants, and anti-inflammatory compounds. The objectives in developing this solution were to achieve superior metabolic support of the kidney during cold storage and to protect against ischemic injury. Inbred Brown Norway rats, weighing 225-250 g, were subjected to orthotopic ultrarapid technique for kidney isotransplantation to minimize warm ischemia and to test the preservation process. The kidney was transplanted after 12 h of preservation. The animals were divided into three groups based upon the preservation solution utilized: HBS solution, HTK solution (Custodiol), and UW solution (UWS)(ViaSpan). Among the recipients, each group had two subsets. The first subset of animals was used to assess survival at 7 days as well as the reperfusion damage index (RDI) based on the macroscopic physical characteristics of the kidney at the time of transplantation. The second subset in each group was utilized to measure serum creatinine and blood urea nitrogen at 4 and 7 days, and histology at death or sacrifice. Mean +/- standard deviation (M +/- SD) was used for all parameters studied. The HBS solution showed significantly better protection at 12 h when compared to HTK and UW solutions. The reperfusion damage index (RDI) showed excellent preservation in the HBS (14 +/- 1), good preservation in UWS (13 +/- 1.5), and moderate preservation in the HTK (11 +/- 2) group. Histology was in concordance with the RDI, showing better histological findings with HBS and UW solutions than with the HTK group. Serum creatinine was significantly better in the HBS group when compared to HTK and UWS. Survival was statistically different, with 80% survival at 7 days in the HBS group, 20% survival in the HTK group, and 50% survival in the UWS group (p < .05). The HBS solution offered a new alternative for kidney cold storage with significantly better results when compared to the current gold standards of HTK and UW solutions in Brown Norway rats. This solution warrants further testing in other mammals.     

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.     

Comparison of histidine-tryptophan-ketoglutarate solution and University of Wisconsin solution for organ preservation in clinical pancreas transplantation

BACKGROUND: University of Wisconsin (UW) solution is currently the standard preservation solution used for abdominal organ transplantation. This study assesses the efficacy of histidine-tryptophan-ketoglutarate (HTK) compared with UW in pancreas transplantation. METHODS: Between October 2002 and August 2003, 20 pancreas transplants were performed. Patients were divided into two groups: UW (n=10) and HTK (n=10). Donor and recipient demographics were similar in both groups. The mean cold ischemia time for both groups was 11 +/-3 hr. RESULTS: There was an anticipated difference between total preservative volumes used (HTK: 4.5 +/- 1.2 L vs. UW: 3.4 +/-0.8 L; P =0.03). Patient and graft survivals to date were 100% in both groups. Serum fasting blood glucose, peak amylase, and serial amylase levels remained comparable at all intervals posttransplantation. CONCLUSIONS: Within this range of cold ischemia time, UW and HTK demonstrate similar efficacy in pancreas preservation.     

A prospective randomized multicenter trial comparing histidine–tryptophane–ketoglutarate versus University of Wisconsin perfusion solution in clinical pancreas transplantation

We aimed to evaluate early pancreas transplant graft function after histidine–tryptophan–ketoglutarate (HTK) versus University of Wisconsin (UW) perfusion. Prospective randomized multicenter study including 68 pancreas transplantations stratified according to preservation fluid used (27 HTK vs. 41 UW). Primary endpoint was pancreas graft survival at 6 months. Serum α-amylase, lipase, C-peptide, HbA1C and exogenous insulin requirement were compared at several time points. Mean pancreas cold ischemia time was 10.8 ± 3.7 (HTK) vs. 11.8 ± 3.4 h (UW) ( P  = 0.247). Simultaneous pancreas–kidney transplantation was performed in 95.6% of the patients, pancreas transplantation alone in 2.9%, and pancreas after kidney transplantation in 1.5%. Six months graft survival was 85.2% (HTK) vs. 90.2% (UW) ( P  = 0.703). Serum amylase and lipase values did not differ between both the groups during the observation period. C-peptide levels were elevated in both the groups without significant differences at each time point. Higher exogenous insulin requirement early after transplantation in the UW group had resolved at 3 months. Six month patient survival was 96.3% (HTK) vs. 100% (UW) ( P  = 0.397). With a mean cold ischemia time of 10 h in this study, HTK and UW solutions appear to be equally suitable for perfusion and organ preservation in clinical pancreas transplantation.     

Post-ischemia normal function of living related kidney transplants after preservation with HTK solution

This study reports on the first clinical use of HTK preservation solution devised by Bretschneider in renal transplantation. Using this HTK solution, nine living related donor kidneys subjected to cold ischemia for up to 4 h were consecutively transplanted between 1987 and 1989. The postoperative function of the donor and recipient kidneys is analyzed. The endogenous creatinine clearance and the plasma creatinine level are used as function parameters. Within 24-48 h after transplantation a postischemic normal graft function occurred. With triple drug therapy the transplanted kidneys showed an increase in renal function identical with that in the donor's single remaining kidney. Within 7 postoperative days no perfusion damage and no HTK or CyA nephrotoxicity was observed.     

Experimental liver preservation with Celsior: a novel alternative to University of Wisconsin and histidine-tryptophan-alpha-ketoglutarate solutions?

Celsior, a low viscosity and low potassium preservation solution, has recently been tested successfully in the cold preservation of heart, lung, kidney and small intestine. The purpose of the present study was to evaluate the potential of Celsior in the cold preservation of the liver. Livers were harvested from male Wistar rats and then flushed with either Celsior (CE), University of Wisconsin solution (UW) or histidine-tryptophan-alpha-ketoglutarate solution (HTK) and stored for 24 h at 4 degrees C in the respective solution. The reperfusion was performed in vitro using a recirculating model with oxygenated (95% O(2), 5% CO(2)) Krebs-Henseleit buffer at 37 degrees C. To simulate the slow rewarming during the surgical implantation in vivo, all livers were stored for 30 min at room temperature prior to reperfusion. After ischemic storage and also after reperfusion some samples were freeze-clamped for analysis of tissue metabolites while others were tested for structural and functional integrity by the isolated perfusion. CE vs. UW vs. HTK: Metabolic preservation of tissue ATP (micromol/g dry weight) during cold storage was best with Celsior (0. 46 +/- 0.17 vs. 0.26 +/- 0.03 vs. 0.35 +/- 0.07; p < 0.05 CE vs. UW), but upon reperfusion energetic recovery was comparable in the three groups (3.45 +/- 0.66 vs. 4.27 +/- 0.41 vs. 3.63 +/- 0.64 micromol/g/dry weight). There appeared to be structural integrity during reoxygenation irrespective of the used preservation solution with comparable values of parenchymal enzyme release (ALT: 575 +/- 82 vs. 547 +/- 106 vs. 593 +/- 38 mU/g/l), bile production (18.0 +/- 1.0 vs. 18.5 +/- 2.5 vs. 18.7 +/- 1.4 microl/g/ min), and the release of acid phosphatase, an indicator for activated Kupffer cells (89 +/- 13 vs. 90 +/- 5 vs. 123 +/- 21 mU/g/l) in this in vitro model. Vascular flow characteristics were approximated by the portal perfusion pressure, which tended to be elevated upon initial reperfusion in the UW group (8.4 +/- 0.6 mm Hg) compared to 6.6 +/- 1.0 and 7.3 +/- 0.4 mm Hg in Celsior and HTK, respectively. However, the pressure values decreased to the normal range even in the UW group with ongoing perfusion. The sensitivity of our model in detecting protective effects of the tested solution was confirmed by a negative control group of livers stored in Ringer's solution at 4 degrees C, yielding an impaired recovery which differed by one magnitude from the three other groups. Within the limits of an in vitro study it is concluded from these results that Celsior may become a suitable alternative for liver preservation and further studies including a transplantation in vivo are strongly encouraged.     

Preservation injury of jejunal grafts and its modulation by custodiol and university of wisconsin perfusion solutions in wistar rats

BACKGROUND: The two preservation solutions most commonly used in human transplantation surgery are University of Wisconsin (UW) and Custodiol (histidine-tryptophan-ketoglutarate; HTK). The aim of our study was to compare the protective effect of UW and HTK solutions on preservation-induced injury of jejunal grafts, as evaluated by the histological changes (semiquantitative method) and small bowel mucosal serotonin levels (as a possible new quantitative method). METHODS: Male Wistar rats (n = 50) weighing 316 +/- 52 g were divided into two main groups according to which preservation solution was used, i.e. UW (n = 25) or HTK (n = 25), and each of these groups was divided into five subgroups according to cold ischemic time (0, 1, 6, 9 and 12 h). Jejunal mucosa biopsy specimens were obtained to determine the serotonin concentration in mucosa and for standard light histology. To grade histological changes in mucosa, Park's small bowel injury grading system was used. RESULTS: Histological examination revealed that injury increased with cold ischemic time in the UW as well as in the HTK group, and there were no significant differences in injury between the two groups, except for the 6-hour cold ischemic period (p < 0.05), when HTK-preserved grafts showed a lower degree of injury (0.97 +/- 0.41) compared with UW-preserved grafts (1.25 +/- 0.39). The mucosal serotonin concentration decreased with cold ischemic time in both groups, and there were significant differences (p < 0.05) in concentrations between the groups after 9 and 12 h of cold ischemia. A significantly higher concentration was measured in grafts preserved in UW solution at these time points. CONCLUSION: The concentration of mucosal serotonin in rat small bowel grafts preserved for 9 and 12 h in UW preservation solution was significantly higher than that in HTK solution. These findings indicate a better protective effect of UW solution on small bowel injury after 9 h of cold ischemia.     

Low viscosity histidine-tryptophan-ketoglutarate graft flush improves subsequent extended cold storage in University of Wisconsin solution in an extracorporeal rat liver perfusion and rat liver transplantation model.

Adequate flushing for liver donation requires large fluid volumes delivered at a high flow. This can be achieved more effectively with crystalloid solutions than with colloid-based solutions. This study examined the combination of initial histidine-tryptophan-ketoglutarate solution (HTK) graft flush and subsequent storage in University of Wisconsin solution (UW) to that of the single use of each solution. Livers from inbred Wistar rats were procured using aortic perfusion with UW or HTK for initial perfusion and reflushed after 30 minutes using either solution. In a third group, after perfusion with HTK, organs were reflushed with UW. A 60-minute in-vitro recirculating perfusion was performed after 24 hours of cold storage in the subsequent solution, as well as allotransplantation after 18 and 24 hours of cold storage. In extracorporeal perfusion, the HTK flush followed by UW storage was superior compared to the single use of either UW or HTK solution, as measured by portal venous pressure, bile flow, liver enzymes released into the effluent perfusate, glycerol leakage, and histological examinations. These data were consistent with the transplantation study. Histological damage and enzyme release after 5-day survival were lowest in the HTK flush and subsequent UW storage groups following 18 hours of cold storage; likewise, the 5-day survival was superior following 24 hours of cold storage. In conclusion, the combined use of HTK solution for initial graft rinse and subsequent storage in UW solution resulted in a cumulative protection. Choosing low-viscosity HTK solution for the initial organ flush may represent a feasible improvement in liver preservation, which also further reduces the required amount of UW solution.     

UW is superior to Celsior and HTK in the protection of human liver endothelial cells against preservation injury.

Celsior solution (CS), a new preservation solution in thoracic organ transplantation, was evaluated for its efficacy in cold preservation of human liver endothelial cells (HLEC) and was compared to University of Wisconsin solution (UW) and histidine-tryptophan-ketoglutarate solution (HTK, Custodiol). HLEC cultures were preserved at 4 degrees C in CS, UW, and HTK, for 2, 6, 12, 24, and 48 hours, with 6 hours of reperfusion. Levels of lactate dehydrogenase (LDH), 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), and adenosine 5'-triphosphate (ATP) were measured after each interval of ischemia and the respective phase of reperfusion. Preservation injury of HLEC as measured by LDH release, intracellular ATP level, and MTT reduction were overall significantly (P CS > HTK.     

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.     

Celsior solution compared with University of Wisconsin solution (UW) and histidine–tryptophan–ketoglutarate solution (HTK) in the protection of human hepatocytes against ischemia–reperfusion injury

Celsior, a new preservation solution in thoracic organ transplantation was evaluated for efficacy in cold preservation of human hepatocytes and compared with University of Wisconsin solution (UW) and histidine-tryptophan-ketoglutarate solution (HTK, Custodiol). Human hepatocyte cultures were preserved at 4 degrees C in Celsior, UW and HTK for 2, 6, 12, 24 and 48 h with 6 h of reperfusion. Levels of lactate dehydrogenase (LDH; cell necrosis), 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT; mitochondrial function), and adenosine 5'-triphosphate (ATP; loss of intracellular energy) were measured. Cell necrosis, mitochondrial dysfunction, and loss of ATP were significantly ( P<0.001, P<0.001, P<0.002, respectively) lower in Celsior than in HTK. The amount of cell necrosis and mitochondrial dysfunction in Celsior solution (CS) and UW was equal ( P=n.s.) up to 24 h and significantly lower in UW after 48 h ( P<0.001). Additionally, the intracellular level of ATP was significantly higher after ischemia ( P<0.001) and reperfusion from long-term ischemia (24, 48 h) ( P<0.002). We can conclude that Celsior was superior to HTK and equal to UW in the protection of human hepatocytes against cold preservation injury from ischemia and reperfusion. Furthermore, Celsior was effective in long-term preservation of human hepatocytes.     

Evaluation of preservation solutions by ESR-spectroscopy: superior effects of University of Wisconsin over Histidine-Tryptophan-Ketoglutarate in reducing renal reactive oxygen species

Despite the causative role of oxidative stress in renal ischemia-reperfusion (I-R) injury effects of preservation solutions on reactive oxygen species (ROS) release have not been sufficiently evaluated. We compared the effects of most common solutions in kidney transplantation, University of Wisconsin (UW) and Histidine-Tryptophan-Ketoglutarate (HTK). ROS formation in isolated perfused rat kidney was detected by electron spin resonance spectroscopy using spin label 1-hydroxy-3-methoxycarbonyl-2,2,5,5-tetramethyl-pyrrolidine. Donor kidneys from Lewis rats were pretreated with saline (controls), in therapeutic groups, kidneys underwent 18 h of cold storage (CS) preserved by HTK or UW solution. Experimental protocol included a stabilization period followed by additional I-R. Kidneys preserved by HTK produced highest ROS values in the control period after CS, whereas levels in UW and control group did not vary significantly. A peak release induced by additional I-R was also significantly highest in HTK kidneys, and UW did not differ from controls. During reperfusion, levels in HTK exceeded control and UW values. Renal vascular resistance, caspase-3-activity, and tissue hydration were enhanced in HTK compared with UW group, whereas ATP concentration was less reduced in UW-preserved tissue. These data show the greater antioxidative potential of UW solution, which also attenuated organ impairment after CS in the early reperfusion period.     

Randomized clinical assay for hepatic grafts preservation with University of Wisconsin or histidine-tryptophan-ketoglutarate solutions in liver transplantation

University of Wisconsin (UW) solution has been the standard for preservation of liver transplantation grafts since 1989. However, some studies demonstrated that histidine-tryptophan-ketoglutarate (HTK) solution is also effective. The purpose of this study was to compare the efficacy of both solutions in liver transplantation. From January 2003 to August 2004 the livers of deceased donors were randomized into HTK and UW groups. The 102 studied patients included 65 (63.7%) in the UW group and 37 (36.3%) in the HTK group. Sex, race, hemodynamic state, use of adrenergic drugs, and presence of steatosis in the donor were similarly distributed in the two groups (P > .05). The mean age of the donors was 38.1 years (SD +/-14.4) in the UW group and 44.6 years (SD +/-14.2) in the HTK cohort (P = .036). Sex, race, age, etiology of the cirrhosis, retransplant, acute liver failure, portal thrombosis, and Child-Pugh and MELD scores in the recipients were similarly distributed in the two recipient samples (P > .05). Among 89 patients who completed 4 months of follow-up, the HTK group included eight cases (25.8%) of biliary complications versus five cases (8.6%) in the UW group (P = .033; OR = 2.0 95% CI = 1.2-3.5). The incidence of graft dysfunction was 2.8% in the HTK group and 9.4% in the UW group (P = .15). In conclusion, UW and HTK solutions were equally effective for the preservation of the hepatic graft. The routine use of HTK solution can reduce the costs of liver transplantation.     

Comparison of solutions for preservation of the rabbit liver as tested by isolated perfusion

The University of Wisconsin (UW) solution consists of a relatively complex mixture of agents. In this study we compared simpler preservation solutions, namely, histidine-tryptophan-ketoglutarate glutarate (HTK) and phosphatebuffered sucrose (PBS) with different compositions of UW solution in the isolated perfused rabbit liver model. Livers were stored cold for 24 and 48 h. After 24 h of preservation, the amount of bile produced in UW-preserved livers was significantly greater (P<0.05) than that in HTK-preserved livers. Also, there was less LDH released into the perfusate in UW-preserved livers. There was more edema and lower K+/Na+ rations in HTK-preserved livers than in UW-preserved livers (all data P<0.05). After 48 h of preservation, the differences between livers preserved in UW or HTK solution were less noticeable than at 24 h and bile production was similar. LDH and AST release were greater in HTK-preserved livers than in UW livers, but these differences were not statistically significant. Preservation in PBS for 48 h was worse than in either UW or HTK solution. Substitution of polyethylene glycol (PEG) for hydroxyethyl starch (HES) in 48-h UW-preserved livers was not effective. We conclude that solutions simpler in composition than UW solution may be effective in kidney transplantation but do not appear suitable for successuful liver preservation.