Perspectives on abdominal organ preservation solutions: a comparative literature review

Melatonin in preservation solutions prevents ischemic injury in rat kidneys

Transplantation is lifesaving and the most effective treatment for end-stage organ failure. The transplantation success depends on the functional preservation of organs prior to transplantation. Currently, the University of Wisconsin (UW) and histidine-tryptophan-ketoglutarate (HTK) are the most commonly used preservation solutions. Despite intensive efforts, the functional preservation of solid organs prior to transplantation is limited to hours. In this study, we modified the UW solution containing components from both the UW and HTK solutions and analyzed their tissue-protective effect against ischemic injury. The composition of the UW solution was changed by reducing hydroxyethyl starch concentration and adding Histidine/Histidine-HCl which is the main component of HTK solution. Additionally, the preservation solutions were supplemented with melatonin and glucosamine. The protective effects of the preservation solutions were assessed by biochemical and microscopical analysis at 2, 10, 24, and 72 h after preserving the rat kidneys with static cold storage. Lactate dehydrogenase (LDH) activity in preservation solutions was measured at 2, 10, 24, and 72. It was not detectable at 2 h of preservation in all groups and 10 h of preservation in modified UW+melatonin (mUW-m) and modified UW+glucosamine (mUW-g) groups. At the 72nd hour, the lowest LDH activity (0.91 IU/g (0.63–1.17)) was measured in the mUW-m group. In comparison to the UW group, histopathological damage score was low in modified UW (mUW), mUW-m, and mUW-g groups at 10, 24, and 72 hours. The mUW-m solution at low temperature was an effective and suitable solution to protect renal tissue for up to 72 h.

Gluconate-Lactobionate-Dextran Perfusion Solutions Attenuate Ischemic Injury and Improve Function in a Murine Cardiac Transplant Model

Static cold storage is the cheapest and easiest method and current gold standard to store and preserve donor organs. This study aimed to compare the preservative capacity of gluconate-lactobionate-dextran (Unisol) solutions to histidine-tryptophan-ketoglutarate (HTK) solution. Murine syngeneic heterotopic heart transplantations (Balb/c-Balb/c) were carried out after 18 h of static cold storage. Cardiac grafts were either flushed and stored with Unisol-based solutions with high-(UHK) and low-potassium (ULK) ± glutathione, or HTK. Cardiac grafts were assessed for rebeating and functionality, histomorphologic alterations, and cytokine expression. Unisol-based solutions demonstrated a faster rebeating time (UHK 56 s, UHK + Glut 44 s, ULK 45 s, ULK + Glut 47 s) compared to HTK (119.5 s) along with a better contractility early after reperfusion and at the endpoint on POD 3. Ischemic injury led to a significantly increased leukocyte recruitment, with similar degrees of tissue damage and inflammatory infiltrate in all groups, yet the number of apoptotic cells tended to be lower in ULK compared to HTK. In UHK- and ULK-treated animals, a trend toward decreased expression of proinflammatory markers was seen when compared to HTK. Unisol-based solutions showed an improved preservative capacity compared with the gold standard HTK early after cardiac transplantation. Supplemented glutathione did not further improve tissue-protective properties.

Perioperative management of adult living donor liver transplantation: Part 1 - recipients

Living donor liver transplantation was first developed to mitigate the limited access to deceased donor organs in Asia in the 1990s. This alternative liver transplantation option has become an established and widely practiced transplantation method for adult patients suffering from end-stage liver disease. It has successfully addressed the shortage of deceased donors. The Society for the Advancement of Transplant Anesthesia and the Korean Society of Transplant Anesthesia jointly reviewed published studies on the perioperative management of live donor liver transplant recipients. The review aims to offer transplant anesthesiologists and critical care physicians a comprehensive overview of the perioperative management of adult live liver transplantation recipients. We feature the status, outcomes, surgical procedure, portal venous decompression, anesthetic management, prevention of acute kidney injury, avoidance of blood transfusion, monitoring and therapeutic strategies of hemodynamic derangements, and Enhanced Recovery After Surgery protocols for liver transplant recipients. This article is protected by copyright. All rights reserved.

Vitrification and Nanowarming of Kidneys

Vitrification can dramatically increase the storage of viable biomaterials in the cryogenic state for years. Unfortunately, vitrified systems ≥3 mL like large tissues and organs, cannot currently be rewarmed sufficiently rapidly or uniformly by convective approaches to avoid ice crystallization or cracking failures. A new volumetric rewarming technology entitled "nanowarming" addresses this problem by using radiofrequency excited iron oxide nanoparticles to rewarm vitrified systems rapidly and uniformly. Here, for the first time, successful recovery of a rat kidney from the vitrified state using nanowarming, is shown. First, kidneys are perfused via the renal artery with a cryoprotective cocktail (CPA) and silica-coated iron oxide nanoparticles (sIONPs). After cooling at -40 °C min-1 in a controlled rate freezer, microcomputed tomography (µCT) imaging is used to verify the distribution of the sIONPs and the vitrified state of the kidneys. By applying a radiofrequency field to excite the distributed sIONPs, the vitrified kidneys are nanowarmed at a mean rate of 63.7 °C min-1 . Experiments and modeling show the avoidance of both ice crystallization and cracking during these processes. Histology and confocal imaging show that nanowarmed kidneys are dramatically better than convective rewarming controls. This work suggests that kidney nanowarming holds tremendous promise for transplantation.

Histidine buffered media maintains pH stabile during cooled transportation of human ovarian tissue

The aim of this study was to investigate whether pH is stable when transporting ovarian tissue in media buffered with either HEPES or histidine. Furthermore, if the choice of transport media impacts the in vitro maturation rate of oocytes collected in connection with ovarian tissue cryopreservation. Human ovaries (n = 34) collected for ovarian tissue cryopreservation were transported immersed in either 30 ml of HEPES buffered (follicle flushing media (Origio; Denmark)) or histidine buffered media (Custodiol®-HTK, Koehler-Chemie, Germany). Tissue was transported on ice for 4–5 h. At arrival, the ovary was weighed, and the pH of the media was measured at 0 °C. From 15 patients, immature oocytes were collected for in vitro maturation, oocytes that matured to metaphase II were evaluated. The pH measured in the HEPES buffered media (pH = 7.5 ± 0.13, n = 18) was significantly higher (p < 0.001) than the pH measured in the histidine buffered media (pH = 7.2 ± 0.05, n = 16). The standard deviation of pH measurements for the histidine buffered media was significantly lower than for the HEPES buffered media measurements (p < 0.0001). A total of 170 and 247 immature oocytes were collected and in vitro matured from ovaries transported in HEPES and histidine buffered media, respectively. The maturation rate of immature oocytes after IVM was similar in the two groups. The results show that pH in the histidine buffered media is closer to the physiological level and more stable than in HEPES buffered medium and support the use of histidine buffered media for cooled transportation of human ovaries.

Development of a Cryoprotective Formula Based on the Fucose-Containing Polysaccharide FucoPol

This study reports the performance of the polysaccharide FucoPol as an enhancer of cryoprotective formulations. FucoPol at a concentration of 0.25% (w/v) was added to several normothermic Dulbecco-derived solutions and hypothermic Euro-Collins, Custodiol-HTK, and Unisol-CV media, substituting some constituents in the latter class to develop FucoPol-based formulations that were tested for their ability to cryopreserve Vero cells. Supplementation yielded post-thaw cell recovery enhancements of at least 70% and averaged at 82%. The FucoPol-supplemented formulations Dulbecco(+)^+FP and Unisol-CV_S3 achieved cell viabilities capable of competing with the commercial cryogenic formula CryoStor CS5. Particularly in Unisol-CV_S3, mannitol, glucose, gluconate, and dextran were all substituted by 0.25% FucoPol, and still, a similar viability was achieved. Multiparametric correlation clustering showed that FucoPol cryoprotection synergizes best with K⁺, Ca²⁺, and Cl^- in its microenvironment. Component substitution analysis demonstrated that FucoPol acts consistently as a cryoprotectant, an impermeant, and a colloidal stabilizer, providing a combined alternative to glucose, mannitol, gluconate, and dextran, thus highlighting its potential in the development of high-performing cryoprotective formulas.

Hypothermic Machine Perfusion of Kidneys Compensates for Extended Storage Time: A Single Intervention With a Significant Impact

INTRODUCTION

Delayed graft function (DGF) adversely affects graft survival and function. Machine perfusion (MP) improves DGF rate and may compensate for extended storage time.

MATERIAL AND METHODS

In this single-center cohort study, we included 193 consecutive kidney transplantations. MP was used in 78 kidneys (36%) and static cold storage (CS) in 115 kidneys (64%). CS kidneys were transplanted first followed by MP kidneys if stored differently. Pairs of kidneys from the same donor were subjected for subgroup analysis and included 58 pairs. The primary endpoints were the rate of DGF and 1- and 5-year graft survival. The secondary endpoints were the rate of the primary nonfunction, mortality, acute rejection, duration of DGF, and 5-year estimated glomerular filtration rate.

RESULTS

Median cold ischemia time (CIT) was significantly different between the MP and CS groups (24 vs 20 hours, P < .05). MP significantly reduced the rate of DGF (MP vs CS: 21.8% vs 42.6%, P < .05, odds ratio 0.34, 95% confidence interval 0.17-0.67) with no impact on overall 1- and 5-year survival rates. Storage method did not affect the duration of DGF, mortality rate, acute rejection, or the 5-year estimated glomerular filtration rate.

CONCLUSIONS

Hypothermic pulsatile MP significantly reduced the rate of DGF in kidneys transplanted with CIT equal to or longer than 12 hours. It is safe and may compensate for longer storage time.

The effect of organ preservation solutions on short-term outcomes after liver transplantation: a single-center retrospective study

The effect of preservation solutions on outcomes has been subject of many debates but the relative benefits of the various solutions remain unclear. We retrospectively compared short-term outcomes of 885 liver transplantations performed between 1/2000 and 12/2017 and preserved with either Histidine-Tryptophan-Ketoglutarate (HTK, n = 190), University of Wisconsin (UW, n = 557), or Institute George Lopez 1 preservation solution (IGL-1, n = 139). Inverse probability of treatment weighting (IPTW) was performed to account for baseline differences between groups and analyses were adjusted for confounders. In the IPTW analyses, peak AST within 7 days was 44% higher (95% CI 15-81%, P < 0.001) in HTK than in UW. Mean model of early allograft function (MEAF) score was 0.61 points (95% CI 0.12-1.10, P = 0.01) higher in HTK than in UW. Early allograft dysfunction (EAD) was more likely to occur with HTK compared to IGL-1 (IPTW OR = 2.87, 95% CI = 1.00-8.19, P = 0.049) and UW (IPTW OR = 1.75, 95% CI = 1.06-2.88, P = 0.023). The type of preservation solution had no impact on hospital stay, ICU stay, incidence of biliary strictures, or graft and recipient survival. HTK was the least effective on reducing graft injury and increased the probability of graft dysfunction after transplantation. UW and IGL-1 were equally effective in reducing graft injury and dysfunction.

Complications during multiorgan retrieval and pancreas preservation

In pancreas transplantation, complications can arise at each step of the process, from the initial selection of donors and recipients through the surgical technique itself and the post-operative period, when lifelong immunosuppression is required. In the early steps, careful retrieval and preservation of the pancreas are crucial for the viability of the organ and ultimate success of the transplant. The pancreas is a low-flow gland, making it highly sensitive to transplantation conditions and presenting risk of pancreatitis due to periods of ischemia. The two groups of donors - after brain death (DBD) or after cardiac arrest (DCD) - require different strategies of retrieval and preservation to avoid or reduce the risk of complications developing during and after the transplantation. For DBD donor transplantation, multiorgan retrieval and cold preservation is the conventional technique. Asystole donor (DCD) transplantation, in contrast, can benefit from the newest technologies, such as hypothermic and especially normothermic preservation machines (referred to as NECMO), to optimize organ preservation. The latter has led to an increase in the pool of donors by facilitating recuperation of organs for transplantation that would have been discarded otherwise.

Impact of Cold Ischemia Time on the Function of Liver Grafts Preserved With Custodiol

OBJECTIVE

This study aimed to evaluate how cold ischemia time (CIT) interferes with liver graft function in the first 7 days after surgery for Custodiol (HTK) preserved organs.

METHODS

This retrospective observational study analyzed the medical records of 38 transplantation patients at Hospital Leforte Liberdade, São Paulo, in 2018. The study population was divided into 2 groups (group A, CIT < 8 hours; group B, CIT > 8 hours). Postoperative parameters-such as international normalized ratio, total bilirubin, aspartate aminotransferase/alanine aminotransferase, alkaline phosphatase, gamma glutamyl transferase (GGT), lactate dehydrogenase, lactate, creatinine, red blood cell transfusion, need for hemodialysis, use of vasoactive drugs, endotracheal intubation time, length of stay in the intensive care unit (ICU), and length of hospital stay-were compared.

RESULTS

Group A (CIT < 8 hours) presented less need for red blood cell transfusions (odds ratio 0.29; confidence interval 0.06-0.98; P = .04), had a shorter hospital stay (P = .024), and had lower levels of total bilirubin (P = .05) and GGT (P = .05) in the first 7 postoperative days. The other variables showed no statistically significant difference.

CONCLUSION

In livers preserved with Custodiol, CIT > 8 hours generated higher levels of total bilirubin and GGT in the postoperative period, in addition to higher hospital costs; greater need for red blood cell transfusions; and longer hospitalization, including longer stays in the ICU.

Evaluation of hyperbranched polyglycerol for cold perfusion and storage of donor kidneys in a pig model of kidney autotransplantation

Hyperbranched polyglycerol (HPG) is a biocompatible polyether polymer that is a potential colloid component in a preservation solution for suppressing interstitial edema during cold storage of a donor organ. This study evaluated the outcomes of kidney transplants after cold perfusion and storage with a HPG‐based preservation solution (HPGS) in a pig model of kidney autotransplantation. The left kidneys of farm pigs (weighing 35–45 kg) were perfused with and stored in either cold HPGS or standard UW solution (UWS), followed by transplantation to the right side after right nephrectomy. The survival and function of transplants were determined by the urine output, and serum creatinine (SCr) and blood urea nitrogen (BUN) of recipients. Transplant injury was examined by histological analysis. Here, we showed that there was no significant difference between HPGS and UWS in the prevention of tissue edema, but HPGS was more effective than UWS for initial blood washout of kidney perfusion and for the prevention of cold ischemia injury during cold storage. After autotransplantation, the kidneys preserved with HPGS (HPG group) had better functional recovery than those with UWS (UW group), indicated by significantly more urine output and lower levels of SCr and BUN. The survived grafts in HPG group had less tissue damage than those in UW group. In conclusion, as compared to the UWS the HPGS has less negative impact on kidney cold ischemia during cold storage, resulting in improving immediate functional recovery after transplantation, suggesting that HPG is a promising colloid for donor kidney preservation.

Structure and Function of Porcine Arteries Are Preserved for up to 6 Days Using the HypoRP Cold-storage Solution

BACKGROUND

Maintaining functional vessels during preservation of vascularized composite allografts (VCAs) remains a major challenge. The University of Wisconsin (UW) solution has demonstrated significant short-term benefits (4-6 h). Here we determined whether the new hypothermic resuscitation and preservation solution HypoRP improves both structure, survival, and function of pig arteries during storage for up to 6 days.

METHODS

Using porcine swine mesenteric arteries, the effects of up to 6-day incubation in a saline (PBS), UW, or HypoRP solution on the structure, cell viability, metabolism, and function were determined.

RESULTS

After incubation at 4°C, for up to 6 days, the structures of the arteries were significantly disrupted, especially the tunica media, following incubation in PBS, in contrast with incubation in the HypoRP solution and to a lesser extent, in UW solution. Those disruptions were associated with increased active caspase 3 indicative of apoptosis. Additionally, while incubation in PBS led to a significant decrease in the metabolic activity, UW and HypoRP solutions allowed a stable to increased metabolic activity following 6 days of cold storage. Functional responsiveness to phenylephrine (PE) and sodium nitroprusside (SNP) decreased over time for artery rings stored in PBS and UW solution but not for those stored in HypoRP solution. Moreover, artery rings cold-stored in HypoRP solution were more sensitive to ATP.

CONCLUSIONS

The HypoRP solution improved long-term cold storage of porcine arteries by limiting structural alterations, including the collagen matrix, reducing apoptosis, and maintaining artery contraction-relaxation functions for up to 6 days.

Preservation Solutions for Kidney Transplantation: History, Advances and Mechanisms

Solid organ transplantation was one of the greatest medical advances during the past few decades. Organ preservation solutions have been applied to diminish ischemic/hypoxic injury during cold storage and improve graft survival. In this article, we provide a general review of the history and advances of preservation solutions for kidney transplantation. Key components of commonly used solutions are listed, and effective supplementations for current available preservation solutions are discussed. At cellular and molecular levels, further insights were provided into the pathophysiological mechanisms of effective ingredients against ischemic/hypoxic renal injury during cold storage. We pay special attention to the cellular and molecular events during transplantation, including ATP depletion, acidosis, mitochondrial dysfunction, oxidative stress, inflammation, and other intracellular mechanisms.

Overnight ovarian tissue transportation for centralized cryobanking: a feasible option

RESEARCH QUESTION

Is overnight transportation of ovarian tissue before cryopreservation in a centralized cryobank from the FertiPROTEKT network feasible?

DESIGN

Data from 1810 women with cryopreserved ovarian tissue after overnight transportation from December 2000 to December 2017 were analysed with a focus on transportation, tissue activity parameters and pregnancy, and delivery rates after transplantation.

RESULTS

A total of 92.4% of tissue samples arrived at ideal temperatures of 2-8°C, 0.4% were transported at temperatures lower than ideal and 6.4% were transported at temperatures that were too high, generally due to mishandling of the inlayed cool packs of the transportation boxes. In 62 women, 78 tissue transplantations were carried out. A subgroup of 30 women who underwent a single orthotopic transplantation with fulfilled criteria of a complete follow-up after transplantation until the end of study, a premature ovarian insufficiency after gonadotoxic therapy as well as the absence of pelvic radiation, was further analysed. In this group, transplantations into a peritoneal pocket accounted for 90%. Transplants were still active at 1 year and above after transplantation in 93.3%. Pregnancy and delivery rates were 46.7% and 43.3%, respectively, with one ongoing pregnancy at the end of the study.

CONCLUSIONS

Overnight transportation for central cryobanking is a feasible concept that results in high reproducible success rates through standardized professional tissue freezing and storage.

Does the type of cardioplegia used during valve surgery influence operative nadir hematocrit and transfusion requirements?

INTRODUCTION

Myocardial protection is performed using diverse cardioplegic (CP) solutions with various combinations of chemical and blood constituents. Newer CP formulations that extend ischemic intervals may require greater asanguineous volume, contributing to hemodilution.

METHODS

We evaluated intraoperative hemodilution and red blood cell (RBC) transfusion rates among three common CP solutions during cardiac valve surgery. Data from 5,830 adult cardiac primary valve procedures where either four-to-one blood CP (4:1), del Nido solution (DN) or microplegia (MP) was used at 173 United States surgical centers. The primary outcome was the nadir hematocrit (Hct) during cardiopulmonary bypass (CPB), with a secondary outcome of total units of RBC transfused intraoperatively. Outcomes were assessed using mixed-effects regression, with controls for patient size, age, first Hct in the operating room, ultrafiltration volume, net bypass circuit priming volume, anesthesia and perfusion asanguineous volumes, cross-clamp and total procedure times, procedure type, reoperation, hospital, surgeon and twelve other patient and procedural variables.

RESULTS

A total of 2,641 patients received 4:1 (45.3%), 1,864 received DN (32.0%) and 1,325 received MP (22.7%). There were only slight differences in the central tendency (mean (SD)) for crude nadir Hct on CPB: 4:1, 25.5 (4.5), DN, 26.0 (4.6) and MP, 26.5 (4.7). After controlling for numerous operative and patient characteristics, the regression-adjusted estimate of the nadir Hct on CPB for MP was 26.2%, compared to 25.7% for 4:1 and 25.7% for DN; differences between MP and the other methods were statistically significant (p<0.01). Unadjusted mean RBC units transfused per patient was very similar across the groups (4:1, 2.2; MP, 2.3; DN, 2.4). Regression-adjusted estimates for the number of units of RBC transfused intraoperatively showed no statistically significant differences between CP methods.

CONCLUSIONS

In patients undergoing cardiac valve surgery, the type of CP did not have a strong clinical impact on hemodilution or transfusion. Choice of a myocardial preservation solution can be made independently of its effect on intraoperative Hct.

Organ preservation: from the past to the future

Organ transplantation is the most effective therapy for patients with end-stage disease. Preservation solutions and techniques are crucial for donor organ quality, which is directly related to morbidity and survival after transplantation. Currently, static cold storage (SCS) is the standard method for organ preservation. However, preservation time with SCS is limited as prolonged cold storage increases the risk of early graft dysfunction that contributes to chronic complications. Furthermore, the growing demand for the use of marginal donor organs requires methods for organ assessment and repair. Machine perfusion has resurfaced and dominates current research on organ preservation. It is credited to its dynamic nature and physiological-like environment. The development of more sophisticated machine perfusion techniques and better perfusates may lead to organ repair/reconditioning. This review describes the history of organ preservation, summarizes the progresses that has been made to date, and discusses future directions for organ preservation.

Liver Transplantation Using Prolonged Cold Ischemia Time Grafts Preserved With Institute George-Lopez-1 Solution

Institute George-Lopez-1 (IGL-1) solution is a preservation solution with lower potassium and lower viscosity than the University of Wisconsin solution that has been recently used in liver transplantation. In the present series, we compare the outcome of liver grafts from brain-dead donors preserved in IGL-1cold storage solution, with cold ischemia times (CITs) longer than 8 hours and those less than 8 hours. Two hundred fifty-two liver transplantations performed from January 2014 to December 2016 at Hospital Santa Isabel, Blumenau, Brazil, were retrospectively analyzed. The patients were divided in two groups according to the CIT. Group I patients (N = 155) had less than 8 hours of CIT with a mean age of 54 ± 11.35 years, whereas group II patients (N = 97) had more than 8 hours of CIT with a mean age of 52 ± 12.5 years. There was no difference between the groups related to indication for liver transplantation and donor characteristics. The only difference statically significant on laboratory data was between the levels of aspartate aminotransferase at day 1 after transplantation. On day 7 post-transplantation there was no difference statistically significant between aspartate aminotransferase, alanine aminotransferase, and bilirubin levels between the two groups. Similar 1-year patient survival rates were found in both groups, with 85.88% for group I and 85.75% in group II. The IGL-1 solution has been shown to be safe, effective, and with good results in liver transplantations. Early graft function and 1-year patient survival rates did not differ when grafts preserved for less than 8 hours were compared to those with CIT greater than 8 hours.

A systematic review and meta-analysis of cold in situ perfusion and preservation of the hepatic allograft: Working toward a unified approach

The efficacy of cold in situ perfusion and static storage of the liver is a possible determinant of transplantation outcomes. The aim of this study was to determine whether there is evidence to substantiate a preference for a particular perfusion route (aortic or dual) or perfusion/preservation solution in donation after brain death (DBD) liver transplantation. The Embase, MEDLINE, and Cochrane databases were used (1980-2017). Random effects modeling was used to estimate effects on transplantation outcomes based on (1) aortic or dual in situ perfusion and (2) the use of University of Wisconsin (UW), histidine tryptophan ketoglutarate (HTK), Celsior, and/or Institut Georges Lopez-1 (IGL-1) solutions for perfusion/preservation. A total of 22 articles were included (2294 liver transplants). The quality of evidence ranged from very low to moderate Grading of Recommendations, Assessment, Development and Evaluations score. Meta-analyses were conducted for 14 eligible studies. Although there was no difference in the primary nonfunction (PNF) rate, a higher peak alanine aminotransferase (ALT) was recorded in dual compared with aortic-only UW-perfused livers (standardized mean difference, 0.24; 95% confidence interval, 0.01-0.47); a back-table portal venous flush was undertaken in the majority of aortic-only perfused livers. There were no relevant differences in peak enzymes, PNF, thrombotic graft loss, biliary complications, or 1-year graft survival in comparisons between dual-perfused livers using UW, HTK, Celsior, or IGL-1. In conclusion, there is no significant evidence that aortic-only perfusion of the DBD liver compromises transplantation outcomes, and it may be favored because of its simplicity. However, there is currently insufficient evidence to advocate for the use of any particular perfusion/preservation fluid over the others. Liver Transplantation 23 1615-1627 2017 AASLD.

Hepatocellular uptake of cyclodextrin-complexed curcumin during liver preservation: A feasibility study

The increasing demand for donor organs and the decreasing organ quality is prompting research toward new methods to reduce ischemia reperfusion injury (IRI). Several strategies have been proposed to protect preserved organs from this injury. Before curcumin/dextrin complex (CDC), a potent antioxidant and anti-inflammatory agent, can be used clinically we need to better understand the intracellular uptake under hypothermic conditions on a rat model of liver donation after circulatory death (DCD) and brain death (DBD). To be able to use the fluorescence of CDC for quantification the stability of CDC in different preservation solutions at 4°C or 37°C was investigated. Livers from Wistar rats were procured after being flushed-out through the portal vein using CDC-enriched preservation solutions and stored at 4°C for variable periods. The CDC signal was stable in different preservation solutions over a period of 4 h and allowed the rapid and lasting uptake of curcumin into cells. After 4 h of preservation, CDC was no longer visible microscopically, and HPLC analysis showed very low to non-detectable tissue levels of CDC, proving metabolization during preservation. However, the distribution of CDC was not affected by warm ischemia damage (p = 0.278) nor by flushing the livers before or after 4 h of cold storage and without a warm preflush. Finally, curcumin reduced oxidative stress, lowered histological injury and did not change gene expression after WI/cold storage. Therefore, the use of CDC flush solution for the initial organ flush can offer a promising approach to the enhancement of liver preservation and the maintenance of its quality.

Advantages of replacing hydroxyethyl starch in University of Wisconsin solution with hyperbranched polyglycerol for cold kidney perfusion

BACKGROUND

Efficient and effective perfusion during organ procurement is required for the best prevention of donor organ injury preceding transplantation. However, current organ preservation solutions, including hydroxyethyl starch (HES)-based University of Wisconsin (UW) solution, do not always yield the best outcomes. Our previous study demonstrated that replacing HES with hyperbranched polyglycerol (HPG) reduced donor heart injury during cold storage. The current research was designed to examine the advantages of HPG-based solution for cold kidney perfusion.

METHODS

Perfusion efficiency of HPG versus UW solution was tested using mouse kidneys at 4°C. The blood washout was evaluated by using a semiquantitative scoring system and tissue damage by histologic analysis. The interaction of HPG or UW solution with human red blood cells (RBCs) was examined by measuring RBC sedimentation and aggregation.

RESULTS

The lower viscosity of HPG solution was correlated with faster and more efficient perfusion through donor kidneys as compared with UW. HPG solution was also more effective than UW in removing RBCs from the kidney and was associated with less tissue damage to donor kidneys. In vitro UW solution caused significant RBC sedimentation and hyperaggregation, whereas HPG showed minimal impact on RBC sedimentation and prevented RBC aggregation.

CONCLUSIONS

This experimental study demonstrated that compared with UW, HPG solution was more efficient and effective in the removal of the blood from donor kidneys and offered better protection from donor tissue damage, suggesting that the HPG solution is a promising candidate to supplant standard UW solution for donor kidney perfusion in transplantation.

Organ preservation review: history of organ preservation

PURPOSE OF REVIEW

To summarize the history of organ preservation and place into this context the current trends in preservation.

RECENT FINDINGS

Multiple large retrospective studies have analyzed cold preservation solutions in an attempt to determine superiority with largely negative results. Experimental and some clinical studies have examined machine perfusion of procured grafts, in both hypothermic and normothermic contexts with variable, but promising, results. Lastly, there are experimental efforts to evaluate mesenchymal stem cell therapy on rehabilitation of marginal donor organs.

SUMMARY

New trends in organ preservation may soon translate into more efficient use of the limited donor pool.

Short term ex vivo storage of kidneys cause progressive nuclear ploidy changes of renal tubular epitheliocytes

In renal transplantation, there has been considerable success, mainly in term of post-transplant graft function. However, upon closer scrutiny, it is known that severe dysfunction, including persistence of renal failure is seen after transplantation. The major condition that potentially cause significant lesion may be hypothesized to be related to the hypothermic approach to storage. To systematically examine these issues, we stored mammalian (sheep) kidneys in UWS at 4 °C for four different time points (0, 1, 3 and 6 hours). We obtained renal histological sections and examined tubular architecture as well as nuclear characteristics of tubular epitheliocytes. The results of our preliminary investigations suggest that there are temporal changes of tubular epitheliocytes, as well as genomic changes. These changes were also seen in tissues stored at room temperature. Our observations suggest the need for additional studies for redesigning of improvised storage solutions. Pilot studies using Celsior also revealed similar kind of nuclear changes, suggesting that storage conditions are contributory, including perfusion versus static conditions. The results may explain persistence of tubular injury several days after orthotopic transplantation, and may potentially be contributory to delayed graft function (DGF).

Organ protective mechanisms common to extremes of physiology: a window through hibernation biology

Supply and demand relationships govern survival of animals in the wild and are also key determinants of clinical outcomes in critically ill patients. Most animals' survival strategies focus on the supply side of the equation by pursuing territory and resources, but hibernators are able to anticipate declining availability of nutrients by reducing their energetic needs through the seasonal use of torpor, a reversible state of suppressed metabolic demand and decreased body temperature. Similarly, in clinical medicine the majority of therapeutic interventions to care for critically ill or trauma patients remain focused on elevating physiologic supply above critical thresholds by increasing the main determinants of delivery of oxygen to the tissues (cardiac output, perfusion pressure, hemoglobin concentrations, and oxygen saturation), as well as increasing nutritional support, maintaining euthermia, and other general supportive measures. Techniques, such as induced hypothermia and preconditioning, aimed at diminishing a patient's physiologic requirements as a short-term strategy to match reduced supply and to stabilize their condition, are few and underutilized in clinical settings. Consequently, comparative approaches to understand the mechanistic adaptations that suppress metabolic demand and alter metabolic use of fuel as well as the application of concepts gleaned from studies of hibernation, to the care of critically ill and injured patients could create novel opportunities to improve outcomes in intensive care and perioperative medicine.

Preservation solutions for static cold storage of abdominal allografts: which is best?

PURPOSE OF REVIEW

To update the reader on the recent literature in liver, kidney, pancreas, and intestine static cold preservation, and to identify which solutions are most advantageous for each organ.

RECENT FINDINGS

The comparison of randomized trials of histidine-tryptophan-ketoglutarate (HTK), Celsior, and University of Wisconsin solutions has shown equivalent risk of delayed graft function after kidney transplantation. Similar outcomes have been observed after pancreas preservation with University of Wisconsin, HTK, and Celsior solution. In live-donor liver transplantation, University of Wisconsin and HTK solution have shown equivalent results, whereas in the recent trials of deceased-donor liver transplantation, University of Wisconsin, HTK, and Celsior solutions have shown equivalence. Contrary to the most clinical trials, national registry data in kidney, pancreas, and liver transplantation demonstrate more detrimental effects and earlier graft loss after preservation with HTK versus University of Wisconsin solution. Early outcomes after intestinal transplantation with University of Wisconsin or HTK solution have shown no significant difference and animal studies indicate intraluminal preservation may be beneficial.

SUMMARY

The University of Wisconsin solution is the standard criterion static cold preservation for the procurement of liver, kidney, pancreas, and intestine. University of Wisconsin, HTK, and Celsior solutions all provide similar allograft outcomes in most clinical trials, but subtle differences have become more apparent in the recent studies and registry reports.