Protective Effects of Different Hypothermal Preservation Solutions on Structure and Function of Isolated Rat Arteries

Objective:With the increasing application of vascular reconstruction in surgical procedures,allogeneic vessels are becoming more popular in clinical practice due to their abundant sources,precise diameter matching,improved histocompatibility,and higher long-term patency rate.This study aimed to investigate the protective effect of various preservation solutions on the function and structure of the isolated rat abdominal aorta preserved under hypothermal conditions.Methods:The study utilized a total of 150 Sprague-Dawley(SD)rats,with 144 rats allocated to the experimental groups and 6 rats allocated to the control groups.The abdominal aorta of the rats was chosen as the subject of our research.The aorta in the experimental groups were randomly assigned to 4 groups:University of Wisconsin(UW)solution group,histidine-tryptophan-ketoglutarate(HTK)solution group,normal saline(NS)group,and sodium lactate Ringer's solution(RS)group.Samples were subjected to examination after preservation periods of 1 day,3 days,5 days,7 days,14 days,30 days,and 90 days.Evaluation of vascular physiological function involved detecting and assessing vasoconstriction ability and measuring cell viability through the MTT test.Evaluation of the vascular wall structure involved tension tolerance tests and pathological staining.Results:The pathogen-positive rate in the HTK group and NS group at 1 month was 16.7%.Regarding the vascular skeleton structure,both the UW group and HTK group exhibited intact structures after 2 weeks of preservation,with slightly edematous collagen and elastic fibers,which was significantly better than that of the NS group and RS group.In terms of cell activity and contractile function,all preservation groups showed similar effects within 2 weeks.However,after 2 weeks,the UW group showed the most favorable preservation effect(P<0.05).In terms of vascular tension,different groups exhibited similar effects within 1 week.However,after 2 weeks,the UW group showed the best preservation effect(P<0.05).Conclusion:All 4 types of preservation solution had a preservation effect on the structure and function of isolated blood vessels during short-term hypothermal preservation.However,after 2-week preservation,the UW solution was found to be the most suitable solution for the preservation of blood vessels.

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 31^(st), 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 histidinetryptophan-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 posttransplant 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.

Current status and perspective of liver preservation solutions

BACKGROUND: A safe and effective preservation solution is a precondition for liver transplantation, which is accepted as the radical treatment for patients with end- stage liver disease. The increasing use of marginal donors and non-heart beating donors as well as the establishment of a national organ allocation network call for better preservation. New preservation solutions like histidine- tryptophan-ketoglutarate (HTK) solution and Celsior solution have been introduced to liver preservation, and protective gene intervention and other modifications have also been investigated. In this article, we review recent advances in liver preservation solutions. DATA SOURCES: An English-language literature search was conducted using MEDLINE (1990-2005) on liver preservation solution, biliary complication, protective gene and other related subjects. RESULTS: Although the high viscosity of the University of Wisconsin (UW) solution proved harmful to the hepatic microcirculation, three solutions showed equivalent preservation effects. When the cold ischemia time was short, there were no significant differences among the three solutions in the incidence of biliary complications. So far, modifications of preservation solutions have achieved great success. Several types of protective genes like A20, Bcl-2, Bcl-XL and HO-1 were reported to have definite liver protective effects. The addition of other substrates like TNF-α antibody, tacrolimus (FK506) and fructose-1, 6-bisphosphate (FBP) can also improve the preservation effect. However, addition of insulin to UW solution is harmful to the graft. CONCLUSIONS: In centers with highly-developed transplantation techniques, HTK and Celsior solutions are acceptable in liver preservation. Protective genemodification and addition of substrates like TNF-α antibody, FK506 and FBP are prominent approaches to improve liver preservation.

Amifostine enhances the antioxidant and hepatoprotective effects of UW and HTK preservation solutions

AIM: To investigate whether amifostine contributes to the antioxidant and cytoprotective effects of histidine-tryptophan-ketoglutarate (HTK) and University of Wisconsin (UW) preservation solutions.

Comparative Study on the Effects of Self-made Liver Preservation Solution on Secretion of ICAM-1 and NO in Rats

In order to study the effect of self-made liver preservation solution on liver preservation by comparing with UW solution and HC-A solution, the self-made liver preservation solution （SM） and perfusion solution were prepared under the aseptic conditions. The isolated non-circulated perfusion rat liver model was established. According to the different preservation solutions, the rats were randomly divided into UW group, SM group and HC-A group. The three groups were divided into 6 subgroups according to the preservation duration （n=6 in each group）. The transferase in liver perfusion solution and intercellular adhesion molecule-1 （ICAM-1） and nitric oxide （NO） in liver tissues were determined at 2, 8 and 24 h respectively. The results showed that the levels of alanine aminotransferase （ALT） and aspartate aminotransferase （AST） had no significant difference between SM group and UW group, but significantly lower than in HC-A group. The levels of ICAM-1 and NO were increased simultaneously in SM group and UW group （P〉0.05）, but there was significant difference as compared with HC-A group （P〈0.05）. At the same time point, the level of ICAM-1 was higher in SM group than in UW group, but NO was lower. The preservation effect of SM solution is the same as UW solution, but better than HC-A solution.

Effect of Sperm Preservation Solution of Pseudobagrus hwanghoensis in Artificial Reproduction Based on SCSA

The quality of fish sperm is an important factor affecting artificial reproduction.Since the sexual maturation of male and female is not synchronized or for the fish that need to kill the male fish for sperm,sperm preservation solution is used to preserve the sperm temporarily during reproduction,in order to meet the needs of large-scale reproduction.Therefore,the preservation effect of sperm preservation solution directly affects the artificial reproduction.The quality of sperm in the preservation solution can be judged macroscopically by microscopic examination,but it is not accurate,while sperm chromatin structure analysis(SCSA)can quantitatively judge the quality of sperm in the preservation solution,thus providing guarantee for reproduction.The Zhaos sperm preservation solution of Pseudobagrus hwanghoensis has been verified by artificial breeding and SCSA analysis for many times,and it is better than Hanks sperm preservation solution.When the DNA fragmentation index is less than or equal to 0.15,the sperm is vigorous and the effect is obvious.

Apoptosis of rat liver in cold preservation with custom-designed KYL solution

BACKGROUND: A suitable perfusate is very important in reducing various problems in liver preservation, prolonging the time of organ preservation and enhancing the quality of donor tissue. University of Wisconsin (UW) solution is the most successful solution for preserving multiple organs at present, but it has many shortcomings. We set out to develop a new liver preservation solution (KYL solution) and study its effects on apoptosis in rat liver undergoing cold preservation. METHODS: Using non-circulated isolated perfused rat liver (IPRL), we randomly preserved Sprague-Dawley rat livers for 0, 4, 8, 16, 24, and 48 hours with KYL solution or UW solution. The effects were assessed by measuring the content of free radicals in Krebs-Henseleit solution and the intracellular calcium content of hepatocytes, assessing hepatocellular apoptosis and related-gene expression, and observing the morphological changes in liver. To evaluate the protection by KYL and UW solutions in rat liver perfusion and preservation, we chosed normal saline for negative comparison. RESULTS: The intracellular calcium content of the liver preserved in KYL solution was less than that preserved in UW solution. At every different period of preservation, the malonaldehyde and superoxide dismutase content in Krebs-Henseleit solution, the percentage of apoptotic cells and the expression patterns of apoptosis-related-genes were similar in livers preserved in KYL and UW solutions. Morphological changes in the two groups were almost the same. The variables in both groups were better than those of livers preserved in normal saline. Both KYL and UW solutions protected rat liver from ischemia-reperfusion injury. CONCLUSIONS: KYL solution is superior to UW solution in preventing calcium overload. More severe hepatocyte damage may appear in the KYL group than in the UW group and the effect of KYL solution on apoptosis in rat liver preservation is similar to that of UW solution.

Experimental Study on the Cryopreservation of LLC-PK1 Epithelial Cells with Hypoxic UW Solution

The effects of oxygen partial pressure on cryopreservation of the cells with organ preservation solution were explored. Hypoxic UW solution was made by purging the UW solution with argon. The pig proximal tubule epithelial cells （LLC-PK1 cells） were cryopreserved in hypoxic UW solution （Ar-UW group） or standard UW solution （UW group） at 4℃ for 48 h. Trypan blue staining and LDH detection were performed to evaluate the injury of the cells. The results showed that the oxygen partial pressure in Ar-UW group was significantly declined from 242±6 mmHg to 83±10 mmHg. After cryopreservation at 4℃ for 48 h, LDH leakage rate and Trypan blue-stained rate in Ar-UW group were （11.3±3.4）% and （10.5±4.7）%, respectively, which were significantly lower than in UW group [（49.5±6.9）% and （47.6±9.3）% respectively, both P〈0.01]. It was concluded that lower oxygen partial pressure of UW solution was more beneficial to the cryopreservation of LLC.

Preparation and Preservation of Hypoxia UW Solution

In order to explore the method to prepare hypoxia UW solution and the stability and preservation of hypoxia UW solution, UW solution was purged by argon or air for 15 min or 60 at a flow rate of 0.8 or 2 L/min, and the oxygen partial pressure of UW solution was detected. The hypoxia UW solution was exposed to the air or sealed up to preserve by using different methods, and the changes of oxygen partial pressure was tested. The results showed that oxygen partial pressure of 50 mL UW solution, purged by argon for 15 min at a flow rate of 2 L/min, was declined from 242±6 mmHg to 83±10 mmHg. After exposure to the air, oxygen partial pressure of hypoxia UW solution was gradually increased to 160±7 mmHg at 48 h. After sealed up by the centrifuge tube and plastic bad filled with argon, oxygen partial pressure of hypoxia UW solution was stable, about 88±13 mmHg at 72 h. It was concluded that oxygen of UW solution could be purged by argon efficiently. Sealed up by the centrifuge tube and plastic bag filled with argon, oxygen partial pressure of UW solution could be stabilized.

Liver graft preservation methods during cold ischemia phase and normothermic machine perfusion

The growing demand for donor organs requires measures to expand donor pool.Those include extended criteria donors, such as elderly people, steatotic livers,donation after cardiac death, etc. Static cold storage to reduce metabolic requirements developed by Collins in late 1960 s is the mainstay and the golden standard for donated organ protection. Hypothermic machine perfusion provides dynamic organ preservation at 4°C with protracted infusion of metabolic substrates to the graft during the ex vivo period. It has been used instead of static cold storage or after it as short perfusion in transplant center. Normothermic machine perfusion(NMP) delivers oxygen, and nutrition at physiological temperature mimicking regular environment in order to support cellular function. This would minimize effects of ischemia/reperfusion injury.Potentially, NMP may help to estimate graft functionality before implantation into a recipient. Clinical studies demonstrated at least its non-inferiority or better outcomes vs static cold storage. Regular grafts donated after brain death could be safely preserved with convenient static cold storage. Except for prolonged ischemia time where hypothermic machine perfusion started in transplant center could be estimated to provide possible positive reconditioning effect. Use of hypothermic machine perfusion in regular donation instead of static cold storage or in extended criteria donors requires further investigation. Multicenter randomized clinical trial supposed to be completed in December 2021. Extended criteria donors need additional measures for graft storage and assessment until its implantation. NMP is actively evaluating promising method for this purpose.Future studies are necessary for precise estimation and confirmation to issue clinical practice recommendations.

Liver graft preservation:an overview

BACKGROUND: The quality of liver graft and outcome of liver transplantation is affected by the length of ischemia time during the donor operation. The retrieved graft may have a serious damage during the time of stoppage of the circulation in the donor until revascularization in the recipient. It is very important to develop a suitable preservation fluid to minimise the damage caused by the ischemic period and to make the surgical procedure semi- elective. DATA SOURCES: An English-language literature search was conducted using MEDLINE (1960-2006) on liver preservation solution, liver transplantation, kidney transplantation and other related subjects. RESULTS: Since 1960 until 2006 many preservation solutions have been introduced. Most of them are based on the effect of hypothermia to minimise the metabolic pathway in the liver graft. In the earlier studies electrolyte solutions were used to perfuse the liver through the portal vein. The first modification in preservation solution was done by Collins who was able to extend the kidney preservation time up to 30 hours. In recent years, the introduction of University of Wisconsin (UW) preservation solution has made a revolution in the field of organ preservation. The UW solution is based on lactobionate and raffinose as impermeants to suppress hypothermic-induced tissue swelling, replacing glucose and mannitol in Collin's solution and hypertonic citrate respectively. Recently a research group in Kyoto University works to produce a more reliable preservation solution. They investigated the importance of saccharides and electrolytes in lung preservation and developed their original ET-Kyoto solution. However, more studies are still needed to evaluate the new ET-Kyoto solution. CONCLUSIONS: The development of new preservation solutions represents a corner stone in the field of organtransplantation. In the future we might be able to extend the time of organ preservation from hours to days.

EXPERIMENTAL STUDY ON THE SEGMENTAL PERFUSION AND PRESERVATION OF SPLEEN

Objective. Spleen transplanlation has developed to be an effective strategy for hemophilia A. But it has not been reported up to date that which kind of established solutions is most suitable for perfusion and preservation of spleen. This study aimed to establish some experiences with the comparison among Hartmann’s solution, Collins’ solution and WMO I solution, in order to instruct the clinical spleen transplantation. Methods. After the splenic artery and vein were dissociated clearly, three kinds of perfusion solutions began to perfuse the corresponding segments of spleen with a randomized sequence. When the efferent fluids from the splenic vein became clear, the perfused spleen segments were preserved for different durations with the same perfusing solution to calculate the survival rate of splencocyte(SRS) and were examined with light and electron microscopy. Results. Among the three solutions, SRS with WMO I solution was significantly higher than those of the other two(P< 0.001). The perfused spleen with WMO I solution showed the slightest morphological changes and a significant longer preservation duration than those with the other two(P<0.05 or P< 0 01). Conclusion. Among the three solutions, WMO I solution was most suitable for perfusion and preservation of spleen.

Trimetazidine:Is it a promising drug for use in steatotic grafts?

AIM： Chronic organ-donor shortage has led to the acceptance of steatotic livers for transplantation, despite the higher risk of graft dysfunction or nonfunction associated with the ischemic preservation period of these organs. The present study evaluates the effects of trimetazidine （TMZ） on an isolated perfused liver model. METHODS： Steatotic and non-steatotic livers were preserved for 24 h in the University of Wisconsin （UW） solution with or without TMZ. Hepatic injury and function （transaminases, bile production and sulfobromophthalein （BSP） clearance） and factors potentially involved in the susceptibility of steatotic livers to ischemia-reperfusion （I/R） injury, including oxidative stress, mitochondrial damage, microcirculatory diseases, and ATP depletion were evaluated. RESULTS： Steatotic livers preserved in UW solution showed higher transaminase levels, lower bile production and BSP clearance compared with non-steatotic livers. Alterations in perfusion flow rate and vascular resistance, mitochondrial damage, and reduced ATP content were more evident in steatotic livers. TMZ addition to UW solution reduced hepatic injury and ameliorated hepatic functionality in both types of the liver and protected against the mechanisms potentially responsible for the poor tolerance of steatotic livers to I/R. CONCLUSION： TMZ may constitute a useful approach in fatty liver surgery, limiting the inherent risk of steatotic liver failure following transplantation.

Performance of cold-preserved rat liver Microorgans as the biological component of a simplified prototype model of bioartificial liver

AIMTo develop a simplified bioartificial liver (BAL) device prototype, suitable to use freshly and preserved liver Microorgans (LMOs) as biological component. METHODSThe system consists of 140 capillary fibers through which goat blood is pumped. The evolution of hematocrit, plasma and extra-fiber fluid osmolality was evaluated without any biological component, to characterize the prototype. LMOs were cut and cold stored 48 h in BG35 and ViaSpan® solutions. Fresh LMOs were used as controls. After preservation, LMOs were loaded into the BAL and an ammonia overload was added. To assess LMOs viability and functionality, samples were taken to determine lactate dehydrogenase (LDH) release and ammonia detoxification capacity. RESULTSThe concentrations of ammonia and glucose, and the fluids osmolalities were matched after the first hour of perfusion, showing a proper exchange between blood and the biological compartment in the minibioreactor. After 120 min of perfusion, LMOs cold preserved in BG35 and ViaSpan® were able to detoxify 52.9% ± 6.5% and 53.6% ± 6.0%, respectively, of the initial ammonia overload. No significant differences were found with Controls (49.3% ± 8.8%, P ® cold preserved LMOs, respectively (n = 6, P CONCLUSIONThis prototype relied on a simple design and excellent performance. It’s a practical tool to evaluate the detoxification ability of LMOs subjected to different preservation protocols.

A study on continuous low-flow perfusion with low-potassium dextran for donor isolated lung preservation

OBJECTIVE: To test the validity of continuous low-flow perfusion with low-potassium dextran (LPD) to preserve rabbit lung. METHODS: Isolated rabbit lungs were preserved for eight hours either in Ringer's solution by simple storage (Group I) or in continuous low-flow perfusion with LPD (Group II). After preservation, lung functions were assessed to compare these two methods. RESULTS: The water gain in Group I was higher than that in Group II. During reperfusion, the functional test values for the immersed lungs were lower than those for the perfused lungs. The lipid peroxidation product (MDA) was significantly decreased in perfused lungs during reperfusion. CONCLUSIONS: Low-flow perfusion with LPD is better than immersion for the lung preservation.

A modified CZ-1 preserving solution for organ transplantation： comparative study with UW preserving solution

Background The University of Wisconsin colloid based preserving solution （UW solution） is the most efficient preserving solution for multiorgan transplantation. Unfortunately, unavailability of delayed organ preserving solutions hindered further progression of cardinal organ transplantation in China. In this study, we validated an organ preserving Changzheng Organ Preserving Solution （CZ-1 solution） and compared it with UW solution. Methods A series of studies were conducted on how and how long CZ-1 solution could preserve the kidneys, livers, hearts, lungs and pancreas of New Zealand rabbits and SD rats. Morphology of transplanted organs was studied by visible microscopy and electron microscopy; biochemical and physiological functions and the survival rate of the organs during prolonged cold storage were studied. Results There was no significant difference between CZ-1 and UW solutions in preserving the kidneys, livers, hearts or lungs of rabbits; kidneys, livers, intestinal mucosa or pancreases of SD rats or five deceased donors＇ testicles. In some aspects, such as preserving rabbits＇ hearts, rats＇ intestinal mucosa and pancreases, the effect of CZ-1 solution was superior to UW solution. CZ-1 could safely preserve kidneys for 72 hours, livers for 24 hours, hearts for 18 hours and lungs for 8 hours for SD rats. Twelve kidneys preserved in cold CZ-1 solution for 22-31 hours were transplanted successfully and the mean renal function recovery time was （3.83±1.68） days. Conclusions CZ-1 solution is as effective as UW solution for organ preservation. The development of CZ-1 solution not only reduces costs and improves preservation of organs, but also promotes future development of organ transplantation in China.