Hypothermic Machine Perfusion Of Kidneys Research Articles

Mesenchymal stromal cell treatment of donor kidneys during ex vivo normothermic machine perfusion: A porcine renal autotransplantation study.

Normothermic machine perfusion (NMP) of injured kidneys offers the opportunity for interventions to metabolically active organs prior to transplantation. Mesenchymal stromal cells (MSCs) can exert regenerative and anti-inflammatory effects in ischemia-reperfusion injury. The aims of this study were to evaluate the safety and feasibility of MSC treatment of kidneys during NMP using a porcine autotransplantation model, and examine potential MSC treatment-associated kidney improvements up to 14days posttransplant. After 75min of kidney warm ischemia, four experimental groups of n=7 underwent 14h of oxygenated hypothermic machine perfusion. In three groups this was followed by 240min of NMP with infusion of vehicle, 10million porcine, or 10million human adipose-derived MSCs. All kidneys were autotransplanted after contralateral nephrectomy. MSC treatment did not affect perfusion hemodynamics during NMP or cause adverse effects at reperfusion, with 100% animal survival. MSCs did not affect plasma creatinine, glomerular filtration rate, neutrophil gelatinase-associated lipocalin concentrations or kidney damage assessed by histology during the 14days, and MSCs retention was demonstrated in renal cortex. Infusing MSCs during ex vivo NMP of porcine kidneys was safe and feasible. Within the short posttransplant follow-up period, no beneficial effects of ex vivo MSC therapy could be demonstrated.

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

IntroductionDelayed graft function (DGF) adversely affects graft survival and function. Machine perfusion (MP) improves DGF rate and may compensate for extended storage time. Material and MethodsIn 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. ResultsMedian 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. ConclusionsHypothermic 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.

Novel Organ Perfusion and Preservation Strategies in Transplantation - Where Are We Going in the United Kingdom?

This review article focuses on current clinical outcomes with novel perfusion strategies in organ transplantation. Broadly, these approaches can be divided into in situ regional perfusion in the donor and ex situ machine perfusion of individual organs. In both settings, hypothermic and normothermic techniques are in clinical use. Evidence from full text articles, abstracts, and data presented at scientific meetings has been considered. Animal studies have been excluded. The review focuses on kidney, liver, pancreas, heart, and lungs. The level of evidence ranges from quasi-experimental work in human pancreas to multiple meta-analyses of Randomized Controlled Trials for hypothermic machine perfusion of kidneys. The data in this review were presented to experts in organ perfusion and preservation at the National Health Service Blood and Transplant Preservation and Perfusion Future Strategy Summit in London in October 2018. The outcomes of the meeting are discussed in the review after due consideration of the available evidence base.

Comparison of the Outcome of Kidney Transplant After Pulsatile or Continuous Ex Vivo Hypothermic Machine Perfusion of Kidneys Donated After Cardiac Death: Analysis of Kidney Pairs

BackgroundHypothermic machine perfusion is used to improve renal perfusion and reduce the rate of early and late graft dysfunction. It has been used in our unit since 2001. It has 2 modes of flow: continuous or pulsatile. The aim of this study is to compare the modes of perfusion in terms of perfusion-related parameters, graft survival, and estimated glomerular filtration rate. MethodsAll donation after cardiac death kidneys between 2002 and 2014 were reviewed. A total of 64 pairs of kidneys were identified of which one kidney underwent pulsatile and the other continuous perfusion. Machine parameters including resistance and perfusion flow index levels at 0, 1, 2, 3, and 4 hours were recorded and glutathione S-transferase was measured in perfusate. Estimated glomerular filtration rate from the first week of transplant until the fifth year and graft survival rates were determined. ResultsMachine parameters were similar at all time points. Estimated glomerular filtration rates and graft survival were the same irrespective of perfusion mode. ConclusionPulsatile perfusion may be regarded as more physiological. However, we could not identify difference in outcome following transplant of kidneys from the same donor that had been perfused under pulsatile or continuous conditions.

The effect on early renal function of various dynamic preservation strategies in a preclinical pig ischemia-reperfusion autotransplant model.

The aims of this study were to determine the most optimal timing to start machine perfusion during kidney preservation to improve early graft function and to evaluate the impact of temperature and oxygen supply during machine perfusion in a porcine ischemia-reperfusion autotransplant model. The left kidney of an approximately 40-kg female Belgian Landrace pig was exposed to 30 minutes of warm ischemia via vascular clamping and randomized to 1 of 6 study groups: (1) 22-hour static cold storage (SCS) (n = 6), (2) 22-hour hypothermic machine perfusion (HMP) (n = 6), (3) 22-hour oxygenated HMP (n = 7), (4) 20-hour HMP plus 2-hour normothermic perfusion (NP) (n = 6), (5) 20-hour SCS plus 2-hour oxygenated HMP (n = 7), and (6) 20-hour SCS plus 2-hour NP (n = 6). Graft recovery measured by serum creatinine level was significantly faster for continuous HMP preservation strategies compared with SCS alone and for all end-ischemic strategies. The active oxygenated 22-hour HMP group demonstrated a significantly faster recovery from early graft function compared with the 22-hour nonactive oxygenated HMP group. Active oxygenation was also found to be an important modulator of a faster increase in renal flow during HMP preservation. Continuous oxygenated HMP applied from the time of kidney procurement until transplant might be the best preservation strategy to improve early graft function.

Comparing the Duration of Hypothermic Machine Perfusion of Kidneys

Comparing the Duration of Hypothermic Machine Perfusion of Kidneys

(13)C glucose labelling studies using 2D NMR are a useful tool for determining ex vivo whole organ metabolism during hypothermic machine perfusion of kidneys.

BackgroundThe aim of this study is to determine the feasibility of using nuclear magnetic resonance (NMR) tracer studies (13C-enriched glucose) to detect ex vivo de novo metabolism in the perfusion fluid and cortical tissue of porcine kidneys during hypothermic machine perfusion (HMP).MethodsPorcine kidneys (n = 6) were subjected to 24 h of HMP using the Organ Recovery Systems LifePort Kidney perfusion device. Glucose, uniformly enriched with the stable isotope 13C ([U-13C] glucose), was incorporated into KPS-1-like perfusion fluid at a concentration of 10 mM. Analysis of perfusate was performed using both 1D 1H and 2D 1H,13C heteronuclear single quantum coherence (HSQC) NMR spectroscopy. The metabolic activity was then studied by quantifying the proportion of key metabolites containing 13C in both perfusate and tissue samples.ResultsThere was significant enrichment of 13C in a number of central metabolites present in both the perfusate and tissue extracts and was most pronounced for lactate and alanine. The total amount of enriched lactate (per sample) in perfusion fluid increased during HMP (31.1 ± 12.2 nmol at 6 h vs 93.4 ± 25.6 nmol at 24 h p < 0.01). The total amount of enriched alanine increased in a similar fashion (1.73 ± 0.89 nmol at 6 h vs 6.80 ± 2.56 nmol at 24 h p < 0.05). In addition, small amounts of enriched acetate and glutamic acid were evident in some samples.ConclusionsThis study conclusively demonstrates that de novo metabolism occurs during HMP and highlights active metabolic pathways in this hypothermic, hypoxic environment. Whilst the majority of the 13C-enriched glucose is metabolised into glycolytic endpoint metabolites such as lactate, the presence of non-glycolytic pathway derivatives suggests that metabolism during HMP is more complex than previously thought. Isotopic labelled ex vivo organ perfusion studies using 2D NMR are feasible and informative.

Hypothermic machine perfusion of kidneys retrieved from standard and high-risk donors.

Hypothermic machine perfusion (HMP) of kidneys is a long-established alternative to static cold storage and has been suggested to be a better preservation method. Today, as our deceased donor profile continues to change towards higher-risk kidneys of lower quality, we are confronted with the limits of cold storage. Interest in HMP as a preservation technique is on the rise. Furthermore, HMP also creates a window of opportunity during which to assess the viability and quality of the graft before transplantation. The technology might also provide a platform during which the graft could be actively repaired, making it particularly attractive for higher-risk kidneys. We review the current evidence on HMP in kidney transplantation and provide an outlook for the use of the technology in the years to come.

Single centre experience of hypothermic machine perfusion of kidneys from extended criteria deceased heart-beating donors: a comparative study

Kidneys from extended criteria donors are associated with higher rates of delayed graft function (DGF). Hypothermic machine perfusion (MP) for storage is associated with more favourable outcomes. A retrospective analysis was performed in 93 patients where the kidney was stored using hypothermic MP (LifePort(®)) and compared to an age-matched control group where the kidney was stored in cold static storage (CSS) using University of Wisconsin solution. Median age was similar in both groups (59.2 years in MP vs 59.9 years in CSS, p = 0.5598). Mean cold storage time was 15.6 h in MP vs 17.9 h in CSS. Post transplant mean serum creatinine was as follows; MP group-144.7 μmol/L at 1 month; 138.3 μmol/L at 3 months and 129.5 μmol/L at 12 months. In the CSS group-163 μmol/L at 1 month; 154.9 μmol/L at 3 months and 140.2 μmol/L at 12 months. There was a statistically significant difference at 1 month (p = 0.0096) and 3 months (p = 0.0236). DGF was defined as the need for haemodialysis within 7 days post transplant. In the MP group, DGF occurred in 17.2 % patients with mean of 6 days (range 1-18). In the CSS group, 25.8 % patients with mean of 8.1 days (range 3-25). One-year graft survival rate was better in the MP group (97.85 vs 96.77 %). Our experience to date recommends the use of hypothermic MP for storage of kidneys from extended criteria deceased heart-beating donors.

Benefits of active oxygenation during hypothermic machine perfusion of kidneys in a preclinical model of deceased after cardiac death donors

BackgroundDeceased after cardiac death donors (DCDs) represent a valuable source of organs; however, preventing poor outcome is difficult, even with the use of machine perfusion (MP). It is of paramount importance to improve this method. We proposed to evaluate the benefits of active oxygenation during kidney graft hypothermic MP using a novel perfusion machine: Kidney Assist (KA). MethodsWe used a pig model of DCD transplantation in Large White pigs. Cold preservation was performed by conventional non-oxygenated MP (KAnoO2) or oxygenated MP (KA). ResultsIn the first 2 wk post-transplant, KA grafts displayed a lower serum creatinine peak and a faster return to normal levels compared with KAnoO2 animals, translating into a smaller area under the curve. Urinary neutrophil gelatinase-associated lipocalin levels and serum aspartate amino transferase levels were lower in KA animals compared with the non-oxygenated group. These correlated with better chronic function. Longer follow-up of the animals (3 mo) permitted evaluation of chronic outcome lesions. Interstitial fibrosis was reduced in the KA group, and these kidneys also displayed significantly lower levels of vimentin staining. Further histologic investigation also showed a trend toward decreased chronic inflammation in kidneys preserved with oxygen. ConclusionsThis new MP system is efficient in preserving DCD kidneys, greatly enhancing the capacity of the graft to withstand preservation stress and improving outcome. Oxygen delivery during preservation is thus valuable for highly damaged organs and offers an important therapeutic tool for transplant teams faced with decreased quality of donor organs.

Initial Experience With Hypothermic Machine Perfusion of Kidneys From Deceased Donors in the Uppsala Region in Sweden

BackgroundSimple cold storage (CS) is the gold standard for organ preservation. Recently, evidence has been presented suggesting compared with CS hypothermic machine perfusion (HMP) improves the quality and outcome of kidneys for transplantation. Uppsala has used the LifePort Kidney Transporter to preserve deceased donor kidneys. We evaluated our first single-center 52 cases retrospectively. MethodsDeceased donor kidneys preserved with HMP between July 2010 and July 2012 (n = 52) were compared with a matched historical cohort of organs preserved by CS between January 2009 and July 2012 (n = 87). We evaluated delayed graft function (DGF), creatinine level at hospital discharge, length of hospital stay, incidence of acute rejection episodes during the first year after transplantation, and graft survival. ResultsBoth groups included approximately 69% expanded criteria donors (ECD). Median cold ischemia time (CIT) was 12.8 hours in the HMP group and 11.7 hours in the CS group. The incidence of DGF was 11.5% with HMP and 20.7% with CS. Compared with CS, HMP significantly reduced the occurrence of DGF from 21.4% to 0% using standard criteria kidneys (P = .046), whereas the use of HMP did not impact the occurrence of DGF with ECD kidneys. The creatinine level at hospital discharge was lower after HMP than after CS (P = .047). No difference in graft survival was observed between the groups. ConclusionsMachine perfusion resulted in a lower occurrence of DGF using kidneys from standard criteria donors with a lower creatinine at hospital discharge among the cohort with reasonably low CIT. Using machine perfusion seems to be safe; no adverse surgical events occurred during the study period.

Role of Oxygenation in Hypothermic Machine Perfusion of Kidneys From Heart Beating Donors

Dynamic preservation of organ grafts by hypothermic machine perfusion (HMP) has regained broader interest to provide better outcome after transplantation. One pivotal aspect still under debate is the role of oxygenation during HMP. The present study investigates functional and molecular aspects of active oxygenation during HMP of kidneys from heart beating donors. Kidneys were retrieved from Landrace pigs (25-30 kg body weight) and preserved by pulsatile HMP for 21 hr. All kidneys were randomly assigned to either anoxic perfusion (MPanox) or active oxygenation of the perfusate (MPox). All grafts were then autotransplanted, and the remaining native kidney was removed at the same time. Renal integrity and function was evaluated during perfusion and for 1 week after the transplantation and the removal of the remaining native kidney. Oxygenation during HMP resulted in lower endischemic vascular resistance and slightly elevated free radical-mediatedtissue injury during HMP. After reperfusion, radical mediated lipid peroxidation was twofold higher in the MPanox group. Renal clearance of creatinine was found significantly better during the first 2 days after transplantation after MPanox than after MPox. Molecular expression of erythropoietin was increased threefold to baseline levels after MPanox, indicating renal hypoxia during preservation, but was remained unchanged after MPox. Gene expression of sodium-glucose transporter reflected similar functional outcome in both groups. Fractional excretion of Na(+), proteinuria, or serum levels of lactate dehydrogenase were similar in both groups. The present data do not support the use of active oxygenation during hypothermic perfusion of kidneys from donors with intact circulation.

Hemodynamic, Biochemical, and Morphological Characteristics During Preservation of Normal Porcine Livers by Hypothermic Machine Perfusion

In renal transplantation, hypothermic machine perfusion optimizes preservation of marginal grafts, assesses their quality prior to transplantation, improves outcome, and may contribute to an increased number of transplantations. Recently, hypothermic machine perfusion has become increasingly popular given the organ shortage and the “obligatory” utilization of marginal organs. Increasing mortality on the liver transplantation waiting list makes it urgent to develop machine perfusion systems for livers, trying to better preserve marginal livers and perhaps to recover currently discarded livers are for clinical transplantation without an increased risk of graft nonfunction. However, data on machine perfusion of livers and perfusion parameters capable of predicting viability are scarce. The aim of this study was to determine the baseline hemodynamic and metabolic profiles and morphology of livers during hypothermic machine perfusion in a porcine model. We used protocol similar to hypothermic machine perfusion of kidneys. Hemodynamic analysis revealed higher vascular resistance in the hepatic artery versus the portal vein. The arterial resistance gradually decreased during perfusion (similar to kidneys), suggesting progressive relaxation of the arterial vasculature, and perhaps better penetration of the microcirculation by the perfusion solution. During hypothermic machine perfusion, transaminases were gradually (but modestly) released, and livers displayed unequivocal signs of aerobic and anaerobic metabolism. After 24 hours, livers appeared morphologically well preserved. In conclusion, this study showed that hypothermic machine perfusion was feasible. During hypothermic machine perfusion, was easily assessed hemodynamic, biochemical, and morphological parameters.

Modulating biochemical perturbations during 72-hour machine perfusion of kidneys: Role of preservation solution

This study documents renal biochemistry during hypothermic machine perfusion of kidneys. It is intended to demonstrate that a comprehensive evaluation of organ viability during ex-vivo preservation is needed to increase the number of organs available for transplantation and to reduce the current renal discard rate. Porcine kidneys were hypothermically machine perfused for 72 h with either Unisol™-UHK or Belzer-Machine Perfusion Solution, (Belzer-MPS). Renal perfusate samples were periodically collected and biochemically analyzed. Significant differences were measured in the renal metabolic activity between the two experimental groups while similar values for traditional parameters such as renal flow rate and vascular resistance values were recorded. The effluent of UHK perfused kidneys showed strong metabolites and NH 4 + dynamics ( P < 0.05 vs. baseline), while the Belzer-MPS kidneys metabolic activity led to little or no change of the effluent biochemistry relative to baseline.