Safety and efficacy of living donor liver preservation with HTK solution

Evaluating the Performance of a Nonelectronic, Versatile Oxygenating Perfusion System across Viscosities Representative of Clinical Perfusion Solutions Used for Organ Preservation

Introduction: On the United States' Organ Transplantation Waitlist, approximately 17 people die each day waiting for an organ. The situation continues to deteriorate as the discrepancy between harvested organs and the number of patients in need is increasing. Static cold storage is the clinical standard method for preserving a harvested organ but is associated with several drawbacks. Machine perfusion of an organ has been shown to improve preservation quality as well as preservation time over static cold storage. While there are machine perfusion devices clinically available, they are costly and limited to specific organs and preservation solutions. This study presents a versatile oxygenating perfusion system (VOPS) that supplies oxygen and pulsatile perfusion. Materials and Methods: Experiments evaluated the system's performance with a human kidney mimicking hydraulic analog using multiple compressed oxygen supply pressures and aqueous solutions with viscosities ranging from 1 to 6.5 cP, which simulated viscosities of commonly used organ preservation solutions. Results and Conclusions: The VOPS produced mean flow rates ranging from 0.6 to 28.2 mL/min and perfusion pressures from 4.8 to 96.8 mmHg, which successfully achieved the desired perfusion parameters for human kidneys. This work provides evidence that the VOPS described herein has the versatility to perfuse organs using many of the clinically available preservation solutions.

Compared efficacy of preservation solutions on the outcome of liver transplantation: Meta-analysis

AIM

To compare the effects of the four most commonly used preservation solutions on the outcome of liver transplantations.

METHODS

A systematic literature search was performed using MEDLINE, Scopus, EMBASE and the Cochrane Library databases up to January 31st, 2017. The inclusion criteria were comparative, randomized controlled trials (RCTs) for deceased donor liver (DDL) allografts with adult and pediatric donors using the gold standard University of Wisconsin (UW) solution or histidine-tryptophan-ketoglutarate (HTK), Celsior (CS) and Institut Georges Lopez (IGL-1) solutions. Fifteen RCTs (1830 livers) were included; the primary outcomes were primary non-function (PNF) and one-year post-transplant graft survival (OGS-1).

RESULTS

All trials were homogenous with respect to donor and recipient characteristics. There was no statistical difference in the incidence of PNF with the use of UW, HTK, CS and IGL-1 (RR = 0.02, 95%CI: 0.01-0.03, P = 0.356). Comparing OGS-1 also failed to reveal any difference between UW, HTK, CS and IGL-1 (RR = 0.80, 95%CI: 0.80-0.80, P = 0.369). Two trials demonstrated higher PNF levels for UW in comparison with the HTK group, and individual studies described higher rates of biliary complications where HTK and CS were used compared to the UW and IGL-1 solutions. However, the meta-analysis of the data did not prove a statistically significant difference: the UW, CS, HTK and IGL-1 solutions were associated with nearly equivalent outcomes.

CONCLUSION

Alternative solutions for UW yield the same degree of safety and effectiveness for the preservation of DDLs, but further well-designed clinical trials are warranted.

Preservation solutions used during abdominal transplantation: Current status and outcomes

Organ preservation remains an important contributing factor to graft and patient outcomes. During donor organ procurement and transportation, cellular injury is mitigated through the use of preservation solutions in conjunction with hypothermia. Various preservation solutions and protocols exist with widespread variability among transplant centers. In this review of abdominal organ preservation solutions, evolution of transplantation and graft preservation are discussed followed by classification of preservation solutions according to the composition of electrolytes, impermeants, buffers, antioxidants, and energy precursors. Lastly, pertinent clinical studies in the setting of hepatic, renal, pancreas, and intestinal transplantation are reviewed for patient and graft survival as well as financial considerations. In liver transplants there may be some benefit with the use of histidine-tryptophan-ketoglutarate (HTK) over University of Wisconsin solution in terms of biliary complications and potential cost savings. Renal grafts may experience increased initial graft dysfunction with the use of Euro-Collins thereby dissuading its use in support of HTK which can lead to substantial cost savings. University of Wisconsin solution and Celsior are favored in pancreas transplants given the concern for pancreatitis and graft thrombosis associated with HTK. No difference was observed with preservation solutions with respect to graft and patient survival in liver, renal, and pancreas transplants. Studies involving intestinal transplants are sparse but University of Wisconsin solution infused intraluminally in combination with an intra-vascular washout is a reasonable option until further evidence can be generated. Available literature can be used to ameliorate extensive variation across centers while potentially minimizing graft dysfunction and improving associated costs.

Use of IGL-1 preservation solution in liver transplantation

University of Wisconsin (UW) solution has been known as the standard solution for liver graft preservation. Alternative preservation solutions have been used in liver transplantation, such as histidine-tryptophan-ketoglutarate (HTK) and Celsior solution. Institut Georges Lopez-1 (IGL-1) is a new preservation solution with lower potassium and lower viscosity than UW solution that has recently been used in liver transplant. Data from 178 patients who received transplants from August 2008 to June 2013 at Hospital Santa Isabel, Blumenau, Brazil, were analyzed. All patients received grafts from brain death donors. In November 2011 we started to use IGL-1 as an alternate preservation solution. Therefore, 53 patients using IGL-1 preserved grafts were compared to 125 using HTK solution. The donor age in the HTK group ranged from 11-77 years, with a mean of 43.4 ± 4.8. In the IGL-1 group donor age ranged from 9-62 years, with a mean of 35.8 ± 4.5. Cold ischemia time in the HTK group ranged from 85-1145 minutes, mean 443.5 ± 183.5 minutes. In the IGL-1 group, cold ischemia time ranged from 85-670 minutes, mean 329.3 ± 134.8 minutes. The overall operative mortality rate was 14% (25 patients); in the HTK group, 14.4% (18 patients); and in the IGL-1 group, 13.4% (7 patients). One graft in the HTK group presented with primary non-function (PNF), 0.7%; there were none in the IGL-1 group. In our study, IGL-1 has been shown to be safe to use as a preservation solution for liver transplantation. Early post-transplant graft function was comparable to that observed with HTK solution, although a tendency for lower alanine aminotransferase levels was noticed. IGL-1 has been shown to be safe, cost efficient, and an effective preservation solution.

Comparative Effects of Phosphoenolpyruvate, a Glycolytic Intermediate, as an Organ Preservation Agent with Glucose and N-Acetylcysteine against Organ Damage during Cold Storage of Mouse Liver and Kidney

We evaluated the usefulness of phosphoenolpyruvate (PEP), a glycolytic intermediate with antioxidative and energy supplementation potentials, as an organ preservation agent. Using ex vivo mouse liver and kidney of a static cold storage model, we compared the effects of PEP against organ damage and oxidative stress during cold preservation with those of glucose or N-acetylcysteine (NAC). Lactate dehydrogenase (LDH) leakage, histological changes, and oxidative stress parameters (measured as thiobarbituric acid reactive substance and glutathione content) were determined. PEP (100 mM) significantly prevented an increase in LDH leakage, histological changes, such as tubulonecrosis and vacuolization, and changes in oxidative stress parameters during 72 h of cold preservation in mouse liver. Although glucose (100 mM) partly prevented LDH leakage and histological changes, no effects against oxidative stress were observed. By contrast, NAC inhibited oxidative stress in the liver and did not prevent LDH leakage or histological changes. PEP also significantly prevented kidney damage during cold preservation in a dose-dependent manner, and the protective effects were superior to those of glucose and NAC. We suggest that PEP, a functional carbohydrate with organ protective and antioxidative activities, may be useful as an organ preservation agent in clinical transplantation.

An experimental rat model of ex vivo lung perfusion for the assessment of lungs regarding histopathological findings and apoptosis: low-potassium dextran vs. histidine-tryptophan-ketoglutarate

OBJECTIVE

To compare histopathological findings and the degree of apoptosis among rat lungs preserved with low-potassium dextran (LPD) solution, histidine-tryptophan-ketoglutarate (HTK) solution, or normal saline (NS) at two ischemia periods (6 h and 12 h) using an experimental rat model of ex vivo lung perfusion.

METHODS

Sixty Wistar rats were anesthetized, randomized, and submitted to antegrade perfusion via pulmonary artery with one of the preservation solutions. Following en bloc extraction, the heart-lung blocks were preserved for 6 h or 12 h at 4 ºC and then reperfused with homologous blood for 60 min in an ex vivo lung perfusion system. At the end of the reperfusion, fragments of the middle lobe were extracted and processed for histopathological examination. The parameters evaluated were congestion, alveolar edema, alveolar hemorrhage, inflammatory infiltrate, and interstitial infiltrate. The degree of apoptosis was assessed using the TdT-mediated dUTP nick end labeling method.

RESULTS

The histopathological examination showed that all of the lungs preserved with NS presented alveolar edema after 12 h of ischemia. There were no statistically significant differences among the groups in terms of the degree of apoptosis.

CONCLUSIONS

In this study, the histopathological and apoptosis findings were similar with the use of either LPD or HTK solutions, whereas the occurrence of edema was significantly more common with the use of NS.

Preservation solutions for liver transplantation in adults: celsior versus custodiol: a systematic review and meta-analysis with an indirect comparison of randomized trials

BACKGROUND

The University of Wisconsin (UW) solution has been recognized as the gold standard for liver preservation; however, it possesses some limitations, and other solutions exist for organ preservation. The aim of this study was to compare the liver functions of transplanted grafts that had been stored in Celsior and Custodiol solutions.

METHODS

We searched the MEDLINE, EMBASE, LILACS, Cochrane Central Register of Controlled Trials, and SCIELO databases. We included randomized and quasi-randomized, controlled trials that compared the efficacy and safety of Celsior and Custodiol with UW solution for liver preservation in adults. The factors that were considered for analysis were their impacts on primary dysfunction (primary nonfunction and initial poor function), ischemic-type biliary lesions, and patient and graft survival rates. Because of the lack of direct evidence, an indirect comparison of Celsior and Custodiol was calculated.

RESULTS

We identified 3 randomized controlled trials and 1 quasi-randomized, controlled trial to pool in a meta-analysis of Celsior versus UW solutions. The number of episodes of primary dysfunction was lower in the Celsior group (7.4%) than in the UW group (9.8%), but the difference was not significant (relative risk [RR], 0.68; 95% confidence interval [CI], 0.22-1.97). Two randomized controlled trials compared Custodiol and Wisconsin solutions were identified. The number of episodes of primary dysfunction was also lower in the Custodiol group (3.0%) compared with the Wisconsin group (8.4%), but the difference was not significant (RR, 0.36; 95% CI, 0.08-1.70). An indirect comparison using data from the main analysis revealed no difference between the Celsior and Custodiol solutions (RR, 1.88; 95% CI, 0.57-6.16).

CONCLUSION

The Celsior and Custodiol solutions performed similarly to UW solution as preservation solutions in liver transplantation clinical settings.

Comparing the performance of rat lungs preserved for 6 or 12 hours after perfusion with low-potassium dextran or histidine-tryptophan-ketoglutarate

INTRODUCTION

In lung transplantation, graft dysfunction is a frequent cause of mortality; the etiopathogenesis is related to ischemia-reperfusion injury. We sought to compare the lung performance of rats after reperfusion after presentation with 3 solutions at 2 ischemia times.

METHODS

We randomized 60 male Wistar rats to undergo anterograde perfusion via the pulmonary artery with low-potassium dextran (LPD), histidine-tryptophan ketoglutarate (HTK), or saline. After extraction, the heart-lung blocks were preserved in a solution at hypothermia for 6 or 12 hours before perfusion with homologous blood for 60 minutes using ex vivo system Isolated Perfused Rat or Guinea Pig Lung System (Harvard Apparatus). Respiratory mechanics, pulmonary weight, pulmonary artery pressure (PAP), and relative lung oxygenation capacity (ROC) measurements were obtained every 10 minutes.

RESULTS

Comparing tidal volume (TV), compliance, resistance, ROC, PAP, and pulmonary weight the LPD, HTK, and saline group did not differ at 6 and 12 hours. The TV was higher in the lungs with 6-hour ischemia in the LPD, HTK, and saline groups. Compliance was higher in the lungs with 6-hour ischemia in the LPD and saline groups. There were no differences in ROC values comparing lungs with 6- versus 12-hour ischemia in the LPD group. A significant difference was observed between lungs in the HTK and saline groups. Resistance was higher in the lungs with 12-hour ischemia among the LPD, HTK, and saline groups. There was a gradual weight increase in the lungs, particularly those undergoing 12-hour ischemia, despite the absence of a significant difference between groups.

CONCLUSION

Rat lungs perfused with LPD and HTK preservation solutions showed similar reperfusion performances in this ex-vivo perfusion model.

Changes in mitochondrial respiratory enzyme activity after ischemia-reperfusion injury in living-donor liver transplantation

BACKGROUND

Ischemia-reperfusion (I-R) injury plays an important role in the immediate graft function in living-donor liver transplantation (LDLT). There is growing evidence that mitochondria play a pivotal role in I-R injury. Our aim was to evaluate changes in mitochondrial respiratory enzyme activities after I-R injury in LDLT.

METHODS

Specimens from 8 donor recipient pairs enrolled in this study were obtained from the donor livers before harvest (before I-R injury) and after vascular anastomosis in the recipient (after I-R injury). Histidine-tryptophan-ketoglutarate solution was used to perfuse the organ during the cold ischemic period between harvesting and transplantation. We correlated changes in mitochondrial respiratory enzyme complex activity (succinate cytochrome c reductase [SCCR]; NADH cytochrome c reductase [NCCR]) after I-R injury with clinical data and graft status.

RESULTS

NCCR and SCCR activities did not uniformly decrease after I-R injury. Two of 8 recipients experienced graft dysfunction after transplantation. The decrease in neither NCCR nor SCCR activity correlated with graft dysfunction in these 2 patients. Among the clinical factors, grafts from older donors tended to show decreased NCCR activity after I-R injury.

CONCLUSIONS

In this study, changes in mitochondrial respiratory enzyme activity failed to predict the severity of I-R injury in LDLT. The organ preservation solution may play a protective role on mitochondrial respiratory enzymes during I-R injury.

Greater hemodynamic instability with histidine-tryptophan-ketoglutarate solution than University of Wisconsin solution during the reperfusion period in living donor liver transplantation

OBJECTIVE

University of Wisconsin (UW) and histidine-tryptophan-ketoglutarate (HTK) solutions are the 2 most commonly used liver preservation solutions. The aim of this study was to compare cardiovascular stability, acid-base status, and potassium concentrations between patients who received grafts preserved in either UW or HTK solution in orthotopic liver transplantation (OLT).

PATIENTS AND METHODS

In this retrospective study, 87 patients who underwent living donor OLT were divided into 2 groups: UW (n = 28) and HTK (n = 59). Group HTK was subdivided into group NF-HTK (n = 31; nonflushed before reperfusion) and group F-HTK (n = 28; flushed before reperfusion). We determined mean arterial pressure (MAP) and heart rate every minute for 5 minutes after reperfusion and the maximum change in these values and incidence of postreperfusion syndrome (PRS). Body temperature, cardiovascular and acid-base parameters, as well as potassium concentrations were compared at 5 minutes before and 5 and 30 minutes after reperfusion.

RESULTS

The maximum decreases in MAP within 5 minutes after reperfusion were significantly greater in both the NF-HTK and the F-HTK groups. The rate of PRS was significantly greater in the NF-HTK compared with the UW group. Flushing with HTK solution decreased the rate of PRS; there was no significant difference between the F-HTK and UW groups. All serial changes in body temperature, cardiovascular and acid-base parameters, as well as potassium concentrations were similar among the 3 groups.

CONCLUSIONS

The incidence of PRS was greater using HTK compared with UW solution during the reperfusion period. Therefore, careful hemodynamic management is advised when using HTK solution.

Comparative Analysis of Clinical Efficacy and Cost between University of Wisconsin Solution and Histidine-Tryptophan-Ketoglutarate

Objective

To compare University of Wisconsin solution (Viaspan), the universal standard for organ preservation, with histidine-tryptophan-ketoglutarate solution. An analysis of each solution, in reference to clinical trials with specific organs, is presented and assessed to find the efficacy of each in a clinical environment. Also to view each solution from an economical standpoint, and in the end develop an overall understanding of the key similarities and differences between each solution in order to assess appropriate use of each in a clinical setting.

Data Sources

A literature search was conducted by using PubMed, MEDLINE, BIOSIS, Embase, and other online data bases to find the most recent studies of University of Wisconsin and histidine-tryptophan-ketoglutarate solutions. Search terms included University of Wisconsin solution, histidine-tryptophan-ketoglutarate, preservation solution, cost analysis, biliary complication, and other related subjects.

Study Selection

Previous research was selected from the literature search to provide basic information on the 2 solutions and also to provide clinical examples of each solution and the efficacy of each with specific organs.

Data Synthesis

Information and published articles on the 2 solutions were gathered for descriptive and comparative purposes.

Conclusions

The 2 solutions appear equally effective in organ preservation. Each solution has its own organ-specific qualities, and each has different complications. The studies reviewed here indicate that the differences are minor and thus suggest that the 2 solutions are equally acceptable for clinical use. Of the 2 solutions, histidine-tryptophan-ketoglutarate costs less than University of Wisconsin solution.

[Preparation and testing of solutions for organ perfusion and preservation in transplantation]

BACKGROUND/AIM

Histidine-tryptophan-ketoglutarate (HTK) solution is the most frequently used solution for the preservation of abdominal organs by leading transplant centers worldwide. The aim of the study was to investigate whether it is possible to prepare this kind of perfusion solution in the hospital pharmacy. In the hospital pharmacy setting we prepared HTK preservation solution and tested its quality, and in accordance with the obtained results recommended its shelf-life.

METHODS

A multicomponent HTK solution was prepared following standardized aseptic procedures for sterile products. Components of HTK solution were dissolved in water for injection under aseptic conditions and the obtained solution was sterilized by bacteriological membrane filtration (0.22 microm). The quality of the produced solution was examined using physical and physico-chemical methods and biological tests. Following pharmacopoeial regulations, we examined clarity, pH value, sterility and performed testing on pyrogens. The content of the amino acids histidine and triptophan was determined by using high pressure liquid chromatography (HPLC) method. The concentrations of chloride ions were investigated by retitration method. Atomic absorption spectrometry and ion-exchange chromatography with conductometric detection were used for determining the level of magnesium and calcium ions and the concentrations of sodium and potassium ions in HTK solution, respectively.

RESULT

It was shown that the quality of the prepared HTK solution complied with the regulation demands. Also, pH value of the solution as a function of storage temperature, remained in the physiological range (pH 7.4).

CONCLUSION

According to the obtained results of physico-chemical and biological testing it can be concluded that in the hospital pharmacy setting with the applied technological procedure, we can produce HTK preservation solution of the required quality. Keeping of HTK preservation solution in a refrigerator at 4 degrees C warrants its shelf-life of six months.

Hepatocytes isolated from neoplastic liver-immunomagnetic purging as a new source for transplantation

AIM: To investigate whether hepatocytes isolated from macroscopically normal liver during hepatic resection for neoplasia could provide a novel source of healthy hepatocytes, including the development of reliable protocols for malignant cells removal from the hepatocyte preparation.

METHODS: Hepatocytes were procured from resected liver of 18 patients with liver tumors using optimised digestion and cell-enrichment protocols. Suspensions of various known quantities of the HT-29 tumor cell line and patient hepatocytes were treated or not with Ep-CAM-antibody-coated immunomagnetic beads in order to investigate the efficacy of tumor-purging by immunomagnetic depletion, using a semi-quantitative RT-PCR method developed to detect tumor cells. Immunomagnetic bead-treated or bead-untreated tumor cell-hepatocyte suspensions were transplanted intra-peritoneally in Balb/C nude mice to assess the rates of tumor development.

RESULTS: Mean viable hepatocyte yield was 9.3 x 10⁶ cells per gram of digested liver with mean viability of 70.5%. Immunomagnetic depletion removed tumor cells to below the RT-PCR detection-threshold of 1 tumor cell in 10⁶ hepatocytes, representing a maximum tumor purging efficacy of greater than 400 000-fold. Transplanted, immunomagnetic bead-purged tumor cell-hepatocyte suspensions did not form peritoneal tumors in Balb/C nude mice. Co-transplantation of hepatocytes with tumor cells did not increase tumorigenesis of the tumor cells.

CONCLUSION: Immunomagnetic depletion appears to be an effective method of purging contaminating tumor cells to below threshold for likely tumorigenesis. Along with improved techniques for isolation of large numbers of viable hepatocytes, normal liver resected for neoplasia has potential as another clinically useful source of hepatocytes for transplantation.

Histidine-tryptophan-ketoglutarate solution vs. University of Wisconsin solution for liver transplantation: a systematic review

University of Wisconsin (UW) solution has been recognized as the gold standard in liver preservation, but its limitations are becoming obvious, such as risk of biliary complications and its high cost. Alternatively, the effects of histidine-tryptophan-ketoglutarate (HTK), such as improved biliary protection and low cost, have been observed. This systematic review is conducted to compare the efficacy and safety of these 2 solutions. Databases from 1966 to June 2006 were searched. Randomized clinical trials (RCTs) and cohort studies comparing HTK and UW solutions for liver transplantation were included. Ten articles including 11 comparisons (1,200 patients) met the inclusion criteria, containing 2 RCTs and 9 cohort studies. No marked differences existed between the 2 groups in patient and graft survival rates, acute rejection, primary nonfunction, primary dysfunction, delayed graft function, and ALT and AST levels after transplantation. The only positive result was observed in the bile production after deceased donor liver transplantation (DDLT), which was statistically significantly higher in HTK group than that of UW group (95% confidence interval, 18.65-57.47; P=0.0001). Although the difference in biliary complications between the 2 groups did not reach statistical significance, HTK was thought to be more effective for biliary tract flush and prevention of biliary complications in some studies. There was no statistically significant difference of effects (except bile production) between HTK and UW. But trends were documented in some studies for the superiority of HTK in biliary tract flush, prevention of biliary complications, and cost saving. Adequately powered RCTs with longer follow-up periods are required to evaluate the long-term effect of these 2 solutions.