Increased primary non-function in transplanted deceased-donor kidneys flushed with histidine-tryptophan-ketoglutarate solution

Advances in Kidney Preservation Techniques and Their Application in Clinical Practice

The use of cold preservation solutions to rapidly flush and cool the kidney followed by static cold storage in ice has been the standard kidney preservation technique for the last 50 y. Nonetheless, changing donor demographics that include organs from extended criteria donors and donation after circulatory death donors have led to the adoption of more diverse techniques of preservation. Comparison of hypothermic machine perfusion and static cold storage techniques for deceased donor kidneys has long been debated and is still contested by some. The recent modification of hypothermic machine perfusion techniques with the addition of oxygen or perfusion at subnormothermic or near-normothermic temperatures are promising strategies that are emerging in clinical practice. In addition, the use of normothermic regional perfusion to resuscitate abdominal organs of donation after circulatory death donors in situ before cold flushing is also increasingly being utilized. This review provides a synopsis of the different types of preservation techniques including their mechanistic effects and the outcome of their application in clinical practice for different types of donor kidney.

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.

Effect of preservation solutions for static cold storage on kidney transplantation outcomes: A National Registry Study

This study aimed to evaluate how 5 preservation solutions for static cold storage affected kidney transplant outcomes. It included all first single kidney transplants during 2010-2014 from donations after brain death in the French national transplant registry, excluding preemptive transplants and transplants of kidneys preserved with a hypothermic perfusion machine. The effects of each preservation solution on delayed graft function (DGF) and 1-year transplant failure were evaluated with hierarchical multivariable logistic regression models. The study finally included 7640 transplanted kidneys: 3473 (45.5%) preserved with Institut Georges Lopez-1 solution (IGL-1), 773 (10.1%) with University of Wisconsin solution, 731 (9.6%) with Solution de Conservation des Organes et Tissus (SCOT, organ and tissue preservation solution), 2215 (29.0%) with Celsior, and 448 (5.9%) with histidine-tryptophan-ketoglutarate. Primary nonfunction rates did not differ by solution. After adjustment for donor, recipient, and transplant characteristics, the DGF risk was significantly lower with IGL-1 than with all other solutions (odds ratio [OR] 0.55, 95% confidence interval [CI] 0.48-0.64). Conversely, SCOT was associated with a DGF risk significantly higher than the other solutions (OR 2.69, 95% CI 2.21-3.27) and triple that of IGL-1 (OR 3.37, 95% CI 2.72-4.16). One year after transplantation, the transplant failure rate did not differ significantly by preservation solution. The difference between the groups for 1-year mean creatinine clearance was not clinically relevant.

Renal Procurement: Techniques for Optimizing the Quality of the Graft in the Cadaveric Setting

PURPOSE OF REVIEW

Kidney transplantation is the best treatment for end-stage renal disease. However, due to organ shortage, suboptimal grafts are increasingly being used.

RECENT FINDINGS

We carried out a review on the methods and techniques of organ optimization in the cadaveric setting. Donor care is the first link in a chain of care. Right after brain death, there is a set of changes, of which hormonal and hemodynamic changes are the most relevant. Several studies have been conducted to determine which drugs to administer, although in most cases, the results are not definitive. The main goal seems rather achieve a set of biochemical and hemodynamic objectives. The ischemia-reperfusion injury is a critical factor for kidney damage in transplantation. One of the ways found to deal with this type of injury is preconditioning. Local and remote ischemic preconditioning has been studied for various organs, but studies on the kidney are scarce. A new promising area is pharmacological preconditioning, which is taking its first steps. Main surgical techniques were established in the late twentieth century. Some minor new features have been introduced to deal with anatomical variations or the emergence of donation after circulatory death. Finally, after harvesting, it is necessary to ensure the best conditions for the kidneys until the time of transplantation. Much has evolved since static cold preservation, but the best preservation conditions are yet to be determined. Conservation in the cold has come to be questioned, and great results have appeared at temperatures closer to physiological.

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.

Hyperbranched polyglycerol as a colloid in cold organ preservation solutions

Hydroxyethyl starch (HES) is a common colloid in organ preservation solutions, such as in University of Wisconsin (UW) solution, for preventing graft interstitial edema and cell swelling during cold preservation of donor organs. However, HES has undesirable characteristics, such as high viscosity, causing kidney injury and aggregation of erythrocytes. Hyperbranched polyglycerol (HPG) is a branched compact polymer that has low intrinsic viscosity. This study investigated HPG (MW-0.5 to 119 kDa) as a potential alternative to HES for cold organ preservation. HPG was synthesized by ring-opening multibranching polymerization of glycidol. Both rat myocardiocytes and human endothelial cells were used as an in vitro model, and heart transplantation in mice as an in vivo model. Tissue damage or cell death was determined by both biochemical and histological analysis. HPG polymers were more compact with relatively low polydispersity index than HES in UW solution. Cold preservation of mouse hearts ex vivo in HPG solutions reduced organ damage in comparison to those in HES-based UW solution. Both size and concentration of HPGs contributed to the protection of the donor organs; 1 kDa HPG at 3 wt% solution was superior to HES-based UW solution and other HPGs. Heart transplants preserved with HPG solution (1 kDa, 3%) as compared with those with UW solution had a better functional recovery, less tissue injury and neutrophil infiltration in syngeneic recipients, and survived longer in allogeneic recipients. In cultured myocardiocytes or endothelial cells, significantly more cells survived after cold preservation with the HPG solution than those with the UW solution, which was positively correlated with the maintenance of intracellular adenosine triphosphate and cell membrane fluidity. In conclusion, HPG solution significantly enhanced the protection of hearts or cells during cold storage, suggesting that HPG is a promising colloid for the cold storage of donor organs and cells in transplantation.

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.

Perspectives on abdominal organ preservation solutions: a comparative literature review

Various preservation solutions are used for kidney, liver, pancreas, small intestine, and multiorgan recoveries and transplants. The effectiveness of these solutions, primarily measured by ability to preserve the organ and graft survival, was analyzed. The 2 most common solutions used for intra-abdominal organs are University of Wisconsin Solution (UW)/Viaspan and Histidine-tryptophan-ketoglutarate (HTK)/Custodiol solution. Outcomes for liver, pancreas, and kidney allografts preserved with these 2 solutions are similar. Although HTK solution shows conflicting results with respect to pancreatic cellular edema, researchers in several studies have noted that HTK solution may be more protective than UW solution against biliary complications in liver transplant. In kidney recoveries, HTK solution may be associated with higher graft loss and increased delayed graft function in marginal deceased donors but had lower incidence of delayed graft function in living donors when compared with UW. UW remains the reference standard for use during multiorgan recoveries but is experiencing strong competition from HTK and other alternative solutions. Some researchers suggest that Celsior's comparable results in abdominal organs and viability for thoracic organs makes it a strong competitor, especially in multiorgan recoveries. Each solution has benefits accompanied by disadvantages. Although it may not be feasible, when considering single-organ recoveries, consideration of alternative solutions may be warranted.

Summary of FDA workshop on ischemia reperfusion injury in kidney transplantation

The Food and Drug Administration (FDA) held an open public workshop in September 2011 to discuss the current state of science related to the effects of ischemia reperfusion injury (IRI) on outcomes in kidney transplantation. Topics included the development of IRI and delayed graft function (DGF), histology and biomarkers, donor factors, recipient factors, organ quality and organ preservation by means of cold storage solutions or machine perfusion. Various mechanisms of injury and maladaptive response to IRI were discussed as potential targets of intervention. Animal models evaluating specific pathophysiological pathways were presented, as were the limitations of extrapolating animal results to humans. Clinical trials of various drug products administered in the peri-transplant period were summarized; a few demonstrated early improvements in DGF, but none demonstrated an improvement in late graft function. Clinical trial design for IRI and DGF were also discussed.

Innovations in organ donation

The growing disparity between organ availability for transplantation and the number of patients in need has challenged the donation and transplantation community of practice to develop innovative processes, ideas, and techniques to bridge the gaps. Advances in the sharing of best practices in the donation community have contributed greatly over the last 8 years. Broader sharing of updated guidelines for declaration of brain death in conjunction with improvements in deceased donor management have increased opportunities for organ donation. New techniques for organ preservation and organ resuscitation have allowed for better utilization of the potential donor pool. This review will highlight processes, ideas, and techniques in organ donation.

Delayed graft function in the kidney transplant

Acute kidney injury occurs with kidney transplantation and too frequently progresses to the clinical diagnosis of delayed graft function (DGF). Poor kidney function in the first week of graft life is detrimental to the longevity of the allograft. Challenges to understand the root cause of DGF include several pathologic contributors derived from the donor (ischemic injury, inflammatory signaling) and recipient (reperfusion injury, the innate immune response and the adaptive immune response). Progressive demand for renal allografts has generated new organ categories that continue to carry high risk for DGF for deceased donor organ transplantation. New therapies seek to subdue the inflammatory response in organs with high likelihood to benefit from intervention. Future success in suppressing the development of DGF will require a concerted effort to anticipate and treat tissue injury throughout the arc of the transplantation process.

Primary nonfunction of renal allograft secondary to acute oxalate nephropathy

Primary nonfunction (PNF) accounts for 0.6 to 8% of renal allograft failure, and the focus on causes of PNF has changed from rejection to other causes. Calcium oxalate (CaOx) deposition is common in early allograft biopsies, and it contributes in moderate intensity to higher incidence of acute tubular necrosis and poor graft survival. A-49-year old male with ESRD secondary to polycystic kidney disease underwent extended criteria donor kidney transplantation. Posttransplant, patient developed delayed graft function (DGF), and the biopsy showed moderately intense CaOx deposition that persisted on subsequent biopsies for 16 weeks, eventually resulting in PNF. The serum oxalate level was 3 times more than normal at 85 μmol/L (normal <27 μmol/L). Allograft nephrectomy showed massive aggregates of CaOx crystal deposition in renal collecting system. In conclusion, acute oxalate nephropathy should be considered in the differential diagnosis of DGF since optimal management could change the outcome of the allograft.

UW is superior compared with HTK after prolonged preservation of renal grafts

BACKGROUND

In recent clinical studies, the efficacy of histidine-tryptophan-ketoglutarate (HTK) in kidney transplantation was questioned. This study compares the efficacy of University of Wisconsin (UW) and HTK solutions on transplantation outcome.

MATERIALS AND METHODS

Rat kidneys were preserved for different periods of cold ischemia (CIT). Heat capacity of the solutions, temperature of the grafts, renal function (RF), and histology were assessed before and after transplantation, respectively.

RESULTS

After prolonged CIT, recipient survival was superior in the UW - (100%) compared with the HTK group (10%). In the latter, severe tubular necrosis, DNA damage, and renal inflammation were observed, reflected by an increased KIM-1, IL6, and P-selectin expression. CIT correlated negatively with RF in both groups. RF recovered significantly faster in the UW group. LDH-release and ATP depletion after cold storage of tubular cells were lower in UW than in HTK. Heat capacity was significantly higher for UW than for HTK. Accordingly, renal temperature was lower.

CONCLUSIONS

Prolonged preservation in UW solution results in a better renal function and less tissue damage compared with HTK, possibly due to improved cooling and better cell viability of the graft. The use of HTK for renal allografts should therefore be reconsidered, particularly when CIT is expected to be long.

Organ Preservation: Current Concepts and New Strategies for the Next Decade

SUMMARY: Organ transplantation has developed over the past 50 years to reach the sophisticated and integrated clinical service of today through several advances in science. One of the most important of these has been the ability to apply organ preservation protocols to deliver donor organs of high quality, via a network of organ exchange to match the most suitable recipient patient to the best available organ, capable of rapid resumption of life-sustaining function in the recipient patient. This has only been possible by amassing a good understanding of the potential effects of hypoxic injury on donated organs, and how to prevent these by applying organ preservation. This review sets out the history of organ preservation, how applications of hypothermia have become central to the process, and what the current status is for the range of solid organs commonly transplanted. The science of organ preservation is constantly being updated with new knowledge and ideas, and the review also discusses what innovations are coming close to clinical reality to meet the growing demands for high quality organs in transplantation over the next few years.

Protective effect of Lifor solution in experimental renal ischemia-reperfusion injury

BACKGROUND

Improved kidney preservation methods are needed to reduce ischemia-reperfusion (IR) injury in kidney allografts. Lifor is an artificial preservation solution comprised of nutrients, growth factors, and a non-protein oxygen and nutrient carrier. The current study compared the effectiveness of Lifor to University of Wisconsin solution (UW) in protecting rat kidneys from warm IR and cold storage injury.

MATERIALS AND METHODS

In a warm IR model, rat kidneys were perfused in situ with either saline, UW, or Lifor for 45 min. Renal function and histology were assessed 24 h later. In a cold IR model, kidney slices were cold-stored in saline, UW, or Lifor at 4°C. Kidney injury was assessed by the release of lactate dehydrogenase (LDH) and immunoblot analysis for cleaved caspase-3.

RESULTS

Lifor perfusion significantly mitigated renal dysfunction and tubular injury at 24 h compared with saline or UW. Lifor and UW prevented LDH release in hypoxic kidney slices in vitro, however activation of caspase-3 following hypoxia-reoxygenation was attenuated only with Lifor. Cold storage with Lifor or UW significantly decreased LDH release from kidney slices or normal rat kidney cells in comparison to storage in saline or culture media. After 24 h of cold storage there was a significant decrease in cleaved caspase-3 in Lifor stored slices compared that seen following cold storage in saline or UW solution.

CONCLUSIONS

Lifor solution mitigates both warm and cold renal IR and appears to provide greater protection from apoptosis compared with UW solution.

A comparison of hypothermic machine perfusion versus static cold storage in an experimental model of renal ischemia reperfusion injury

INTRODUCTION

There is increasing support for the use of hypothermic machine perfusion (HMP) in an attempt to reduce preservation injury. However, experimental evidence is needed to further examine the effects of HMP on renal ischemia reperfusion injury.

METHODS

Porcine kidneys were subjected to 10 min of warm ischemia followed by 18 hr of static cold storage with hyperosomolar citrate (HOC), histidine-tryptophan-ketoglutarate (HTK), or University of Wisconsin (UW) solutions or 18 hr HMP with Kidney Perfusion Solution using the Lifeport perfusion system. Renal function, oxidative damage, and morphology were assessed during 3 hr of reperfusion with autologous blood using an isolated organ perfusion system.

RESULTS

During reperfusion, intrarenal resistance was significantly lower in the HMP group compared with HOC and UW (area under the curve; HMP 3.8+/-1.7, HOC 9.1+/-4.3, UW 7.7+/-2.2, HTK 5.6+/-1.9 mm Hg/min; P=0.006), and creatinine clearance was significantly higher compared with the UW group (area under the curve creatinine clearance; HMP 9.8+/-7.3, HOC 2.2+/-1.7, UW 1.8+/-1.0, HTK 2.1+/-1.8 mL/min/100 g; P=0.004). Tubular function was significantly improved in the HMP group (P<0.05); however, levels of lipid peroxidation were significantly higher (P=0.005).

CONCLUSION

HMP demonstrated a reduced level of preservation injury compared with the static techniques resulting in improved renal and tubular function and less tubular cell inflammation during reperfusion.