Machine Perfusion Group Research Articles

The Potential Utilization of Machine Perfusion to Increase Transplantation of Macrosteatotic Livers.

The demand for liver transplantation has led to the utilization of marginal grafts including moderately macrosteatotic livers (macrosteatosis ≥30% [Mas30]), which are associated with an elevated risk of graft failure. Machine perfusion (MP) has emerged as a technique for organ preservation and viability testing; however, little is known about MP in Mas30 livers. This study evaluates the utilization and outcomes of Mas30 livers in the era of MP. The Organ Procurement and Transplantation Network database was queried to identify biopsy-proven Mas30 deceased donor liver grafts between June 1, 2016, and June 23, 2023. Univariable and multivariable models were constructed to study the association between MP and graft utilization and survival. The final cohort with 3317 Mas30 livers was identified, of which 72 underwent MP and were compared with 3245 non-MP livers. Among Mas30 livers, 62 (MP) and 1832 (non-MP) were transplanted (utilization of 86.1% versus 56.4%, P < 0.001). Donor and recipient characteristics were comparable between MP and non-MP groups. In adjusted analyses, MP was associated with significantly increased Mas30 graft utilization (odds ratio, 7.89; 95% confidence interval [CI], 3.76-16.58; P < 0.001). In log-rank tests, MP was not associated with 1- and 3-y graft failure (hazard ratio, 0.49; 95% CI, 0.12-1.99; P = 0.319 and hazard ratio 0.43; 95% CI, 0.11-1.73; P = 0.235, respectively). The utilization rate of Mas30 grafts increases with MP without detriment to graft survival. This early experience may have implications for increasing the available donor pool of Mas30 livers.

Hypothermia or Machine Perfusion in Kidney Donors

BackgroundTherapeutic hypothermia in brain-dead organ donors has been shown to reduce delayed graft function in kidney recipients after transplantation. Data are needed on the effect of hypothermia as compared with machine perfusion on outcomes after kidney transplantation.MethodsAt six organ-procurement facilities in the United States, we randomly assigned brain-dead kidney donors to undergo therapeutic hypothermia (hypothermia group), ex situ kidney hypothermic machine perfusion (machine-perfusion group), or both (combination-therapy group). The primary outcome was delayed graft function in the kidney transplant recipients (defined as the initiation of dialysis during the first 7 days after transplantation). We also evaluated whether hypothermia alone was noninferior to machine perfusion alone and whether the combination of both methods was superior to each of the individual therapies. Secondary outcomes included graft survival at 1 year after transplantation.ResultsFrom 725 enrolled donors, 1349 kidneys were transplanted: 359 kidneys in the hypothermia group, 511 in the machine-perfusion group, and 479 in the combined-therapy group. Delayed graft function occurred in 109 patients (30%) in the hypothermia group, in 99 patients (19%) in the machine-perfusion group, and in 103 patients (22%) in the combination-therapy group. Adjusted risk ratios for delayed graft function were 1.72 (95% confidence interval [CI], 1.35 to 2.17) for hypothermia as compared with machine perfusion, 1.57 (95% CI, 1.26 to 1.96) for hypothermia as compared with combination therapy, and 1.09 (95% CI, 0.85 to 1.40) for combination therapy as compared with machine perfusion. At 1 year, the frequency of graft survival was similar in the three groups. A total of 10 adverse events were reported, including cardiovascular instability in 9 donors and organ loss in 1 donor owing to perfusion malfunction.ConclusionsAmong brain-dead organ donors, therapeutic hypothermia was inferior to machine perfusion of the kidney in reducing delayed graft function after transplantation. The combination of hypothermia and machine perfusion did not provide additional protection. (Funded by Arnold Ventures; ClinicalTrials.gov number, NCT02525510.)

Trends and Outcomes of Hypothermic Machine Perfusion Preservation of Kidney Allografts in Simultaneous Liver and Kidney Transplantation in the United States.

Optimal kidney graft outcomes after simultaneous liver-kidney (SLK) transplant may be threatened by the increased cold ischemia time and hemodynamic perturbations of dual organ transplantation. Hypothermic machine perfusion (MP) of kidney allografts may mitigate these effects. We analyzed U.S. trends and renal outcomes of hypothermic non-oxygenated MP vs. static cold storage (CS) of kidney grafts from 6,689 SLK transplants performed between 2005 and 2020 using the United Network for Organ Sharing database. Outcomes included delayed graft function (DGF), primary non-function (PNF), and kidney graft survival (GS). Overall, 17.2% of kidney allografts were placed on MP. Kidney cold ischemia time was longer in the MP group (median 12.8 vs. 10.0h; p < 0.001). Nationally, MP utilization in SLK increased from <3% in 2005 to >25% by 2019. Center preference was the primary determinant of whether a graft underwent MP vs. CS (intraclass correlation coefficient 65.0%). MP reduced DGF (adjusted OR 0.74; p = 0.008), but not PNF (p = 0.637). Improved GS with MP was only observed with Kidney Donor Profile Index <20% (HR 0.71; p = 0.030). Kidney MP has increased significantly in SLK in the U.S. in a heterogeneous manner and with variable short-term benefits. Additional studies are needed to determine the ideal utilization for MP in SLK.

Hypothermic Machine Perfusion in Liver Transplantation — A Randomized Trial

BackgroundTransplantation of livers obtained from donors after circulatory death is associated with an increased risk of nonanastomotic biliary strictures. Hypothermic oxygenated machine perfusion of livers may reduce the incidence of biliary complications, but data from prospective, controlled studies are limited.MethodsIn this multicenter, controlled trial, we randomly assigned patients who were undergoing transplantation of a liver obtained from a donor after circulatory death to receive that liver either after hypothermic oxygenated machine perfusion (machine-perfusion group) or after conventional static cold storage alone (control group). The primary end point was the incidence of nonanastomotic biliary strictures within 6 months after transplantation. Secondary end points included other graft-related and general complications.ResultsA total of 160 patients were enrolled, of whom 78 received a machine-perfused liver and 78 received a liver after static cold storage only (4 patients did not receive a liver in this trial). Nonanastomotic biliary strictures occurred in 6% of the patients in the machine-perfusion group and in 18% of those in the control group (risk ratio, 0.36; 95% confidence interval [CI], 0.14 to 0.94; P=0.03). Postreperfusion syndrome occurred in 12% of the recipients of a machine-perfused liver and in 27% of those in the control group (risk ratio, 0.43; 95% CI, 0.20 to 0.91). Early allograft dysfunction occurred in 26% of the machine-perfused livers, as compared with 40% of control livers (risk ratio, 0.61; 95% CI, 0.39 to 0.96). The cumulative number of treatments for nonanastomotic biliary strictures was lower by a factor of almost 4 after machine perfusion, as compared with control. The incidence of adverse events was similar in the two groups.ConclusionsHypothermic oxygenated machine perfusion led to a lower risk of nonanastomotic biliary strictures following the transplantation of livers obtained from donors after circulatory death than conventional static cold storage. (Funded by Fonds NutsOhra; DHOPE-DCD ClinicalTrials.gov number, NCT02584283.)

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.

A Randomized Controlled Trial of Dual Hypothermic Oxygenated Machine Perfusion in Donation after Circulatory Death Liver Transplantation

Purpose: Transplantation of livers from donation after circulatory death (DCD) donors is associated with an increased risk of non-anastomotic biliary strictures (NAS). Hypothermic oxygenated machine perfusion of livers may reduce the incidence of biliary complications, but data from prospective controlled studies are lacking. Method: In this multicenter, controlled trial we randomly assigned patients undergoing transplantation of a DCD liver to receive that liver after dual hypothermic oxygenated machine perfusion or conventional static cold storage alone (control group). The primary end point was the occurrence of NAS within 6 months after transplantation. Secondary end points included other graft-related and general complications. Results: A total of 156 patients were enrolled; 78 participants received a machine perfused liver and 78 received a liver after static cold storage only. NAS occurred in 6% of the patients in the machine perfusion group and 18% of the controls (risk ratio, 0.36; 95%CI, 0.14-0.94; P= 0.03). Post-reperfusion syndrome occurred in 13% of the recipients of a machine perfused liver and in 27% of the controls (risk ratio, 0.43; 95%CI, 0.20-0.91; P = 0.03). Early allograft dysfunction occurred in 26% of machine perfused livers vs. 40% of controls (risk ratio 0.61; 95%CI, 0.39-0.96; P = 0.03). Cumulative number of treatments for NAS was almost 4-fold lower after machine perfusion, compared to controls. There were no significant differences in adverse events. Conclusion: In this randomized trial, hypothermic oxygenated machine perfusion led to a lower risk of NAS, post-reperfusion syndrome and early allograft dysfunction after DCD liver transplantation than conventional static cold storage.

The Impact of Hypothermic Pulsatile Machine Perfusion Versus Static Cold Storage: A Donor-Matched Paired Analysis in a Scenario of High Incidence of Delayed Kidney Graft Function.

BackgroundThe present study analyzed the impact of hypothermic pulsatile machine perfusion (MP) following a long period of static cold (SC) storage in the peculiar Brazilian scenario of high incidence of delayed graft function (DGF), despite good donor characteristics.Material/MethodsA retrospective analysis, with a 1-year follow-up, of 206 recipients of donor-matched paired kidneys was performed. Of the 206 donor kidneys, 103 were maintained exclusively in static cold storage (SC group) and 103 were kept on machine perfusion after a period of SC preservation (MP group). All donors were brain dead.ResultsOnly 4.9% of the kidneys were from expanded-criteria donors. Static cold ischemia time (CIT) in the SC group was 20.8±4.1 hours vs. 15.8±6.2 hours in the MP group (P<0.001). Dynamic CIT in the MP group was 12.3±5.7 hours. MP significantly reduced DGF incidence (29.1% vs. 55.3%, P<0.001), and this effect was confirmed in multivariable analysis (OR, 1.115; 95% CI, 1.033–1.204, P=0.001). No differences were observed between the groups with regard to DGF duration, length of hospital stay, incidence of primary nonfunction and acute rejection, graft loss, death, or renal function.ConclusionsIn this Brazilian setting, MP following a long period of SC preservation was associated with reduced DGF incidence in comparison with SC storage without MP.

Cold Pulsatile Machine Perfusion Versus Static Cold Storage for Kidneys Donated After Circulatory Death: A Multicenter Randomized Controlled Trial.

The benefits of cold pulsatile machine perfusion (MP) for the storage and transportation of kidneys donated after circulatory death are disputed. We conducted a UK-based multicenter, randomized controlled trial to compare outcomes of kidneys stored with MP versus static cold storage (CS). Fifty-one pairs of kidneys donated after circulatory death were randomly allocated to receive static CS or cold pulsatile MP. The primary endpoint, delayed graft function, was analyzed by "intention-to-treat" evaluation. There was no difference in the incidence of delayed graft function between CS and MP (32/51 (62.8%) and 30/51 (58.8%) P = 0.69, respectively), although the trial stopped early due to difficulty with recruitment. There was no difference in the incidence of acute rejection, or in graft or patient survival between the CS and MP groups. Median estimated glomerular filtration rate at 3 months following transplantation was significantly lower in the CS group compared with MP (CS 34 mL/min IQR 26-44 vs MP 45 mL/min IQR 36-60, P = 0.006), although there was no significant difference in estimated glomerular filtration rate between CS and MP at 12 months posttransplant. This study is underpowered, which limits definitive conclusions about the use of MP, as an alternative to static CS. It did not demonstrate that the use of MP reduces the incidence of delayed graft function in donation after circulatory death kidney transplantation.

Hypothermic Ex Situ Perfusion of Human Limbs With Acellular Solution for 24 Hours

Machine perfusion (MP) has evolved as a promising approach for the ex situ preservation in organ transplantation. However, the literature on the use of MP in human vascularized composite allografts is scarce. The aim of this study was to evaluate the effects of hypothermic MP with an acellular perfusate in human upper extremities and compare with the current gold standard of static cold storage (SCS). Six upper extremities were assigned to either MP (n = 3) or SCS (n = 3) conditions for 24 h. MP-extremities were perfused with oxygenated Steen solution at a constant pressure of 30 mm Hg and 10°C. Median total ischemia time was 213 min (range, 127-222 min). Myoglobin, creatine-kinase (CK) showed increased levels at the start of MP (medians: myoglobin: 4377 ng/mL, CK: 1442 U/L), peaking 6 h after perfusate exchange (medians: myoglobin: 9206 ng/mL, CK: 3995 U/L) at timepoint 24. Lactate levels decreased from a median of 6.9-2.8 mmol/L over time. Expression of hypoxia-inducible factor 1-alpha peaked in the SCS-group after 8 h, followed by a decrease. Increased hypoxia-inducible factor 1-alpha expression in the MP group was delayed until 20 h. Perfusion pressure, temperature, and circuit flow were maintained at median of 30.88 mm Hg, 9.77°C, and 31.13 mL/min, respectively. Weight increased 1.4% in the SCS group and 4.3% in the MP group over 24 h. Hypothermic ex situ perfusion with an oxygenated acellular Steen solution may extend the allowable extracorporeal preservation time by a factor of 4-6 compared to SCS and holds promise to be beneficial for vascularized composite allograft recipients and victims of traumatic major limb amputation.

Outcomes of Deceased Donor Kidney Transplantation Using Expanded Criteria Donor Kidneys Following Pulsatile Preservation.

AimWe compared the outcomes of transplanting expanded criteria donor (ECD) kidneys undergoing machine perfusion (MP) versus cold storage (CS).Material and methodsData on all expanded criteria deceased donor kidney transplants performed at the University of Pittsburgh Medical Center from January 2003 through December 2012 were collected from an in-house electronic repository. There were 78 patients in the MP group and 101 patients in the CS group. The majority of the ECD kidneys were imported from other organ procurement organizations: 69 of 73 in the MP group (94.5%, 5 from unknown sources); and 90 of 99 in the CS group (91%), 2 from an unknown source). Most of the patients in the MP group (77 of 78) received a combination of MP and static CS. MP was performed just prior to transplantation in all MP patients. We used descriptive statistics to characterize our sample. We used logistic regression analysis to model the binary outcome of delayed graft function (DGF; i.e., “yes/no”) and Cox (proportional hazard) regression to model time until graft failure. The Kaplan-Meier product-limit method was used to estimate survival curves for graft and patient survival.ResultsA total of 179 transplants were done from ECD donors (MP, 78; CS, 101). The mean static cold storage time was 14 ± 4.1 hours and the mean machine perfusion time was 11.2 ± 6.3 hours in the MP group. The donor creatinine was higher (1.3 ± 0.6 mg/dl vs. 1.2 ± 0.4 mg/dl, p = 0.01) and the cold ischemia time was longer (28.9 ± 10 hours vs. 24 ± 7.9 hours, p = 0.0003) in the MP patients. There were no differences between the two groups in DGF rate (20.8% [MP] vs. 25.8% [CS], p = 0.46), six-year patient survival (74% [MP] vs. 63.2% [CS], p = 0.11), graft survival (64.3% [MP] vs. 51.5% [CS], p = 0.22), and serum creatinine levels (1.5 mg/dl vs. 1.5 mg/dl) on univariate analysis. On unadjusted analysis, MP subjects without DGF had longer graft survival compared to CS subjects with DGF (p < 0.0032) and MP subjects with DGF (p < 0.0005). MP subjects without DGF had longer death-censored graft survival compared to CS subjects with DGF (p < 0.0077) and MP subjects with DGF (p < 0.0016). However, on regression analysis, MP subjects had longer graft survival than CS subjects when DGF was not present. MP subjects without DGF had longer patient survival compared to CS subjects with DGF (p < 0.0289), on unadjusted analysis. MP subjects had a reduced risk of graft failure (hazard ratio [HR], 0.34; 95% confidence interval [CI], 0.17, 0.68) and death-censored graft failure (HR, 0.44; 95% CI, 0.19, 1.00), compared to CS subjects when DGF was not present.ConclusionsReduction of DGF rates for imported ECD kidneys is vital to optimize outcomes and increase their utilization. One strategy to decrease DGF rates may be to reduce static CS time during transportation, by utilizing a portable kidney perfusion machine.

Impact of Machine Perfusion on Delayed Graft Function and Graft Survival from High-Risk Donors

Introdution Kidney transplantation (KT) is the treatment of choice for patients with end-stage chronic kidney disease. After KT, the graft may not function immediately and the patient needs to undergo dialysis, characterizing delayed graft function (DGF). DGF increases length of hospital stay, costs and reduces graft survival. The incidence of DGF is higher in expanded criteria donor (ECD), prolonged cold ischemia time (CIT) and donors with renal dysfunction. There are two methods of renal preservation: the traditional, cold storage (CS) and machine perfusion (MP). MP is a high-cost technology, restricted to few hospitals and studies showed that it reduces the incidence of DGF. Objectives Analyze the incidence of DGF, its duration, CIT, length of hospital stay, graft and patient survival one year after transplantation and renal function estimated by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation at 1, 3, 6, 9 and 12 months in patients transplanted with CS kidneys compared to MP after CS. Methods: This study was retrospective cohort, in a single center. We included transplants from DCE or standard deceased donors if CIT ≥ 24 hours, cardiorespiratory arrest before donation or creatinine ≥1.8mg/dL prior to retrieval from January 2015 to December 2016 with 1 year follow up. Results Sample was 92 patients, 52 transplanted with kidneys in MP. Demographic characteristics were similar between groups except for age of recipient that was higher in the MP group, p=0.03 and donor creatinine prior to retrieval which was 0.7mg/dL higher in the CS group, p=0.01. The incidence of DGF was 86.5% in the MP group and 95% in the CS group, p=0.29. There was no difference in DGF duration between groups. The MP patients remained 7 days less hospitalized than the patients in CS, p = 0.15. CIT was 8.19 hours higher in the MP group, p<0.01. CIT of kidneys in MP was 13.63 hours. Graft survival was 90.4% in the MP group and 87.5% in the CS patients, p = 0.69. Patient survival was 94.2% in the MP group and 95% in the PE group, p = 0.86. There were no differences in creatinine clearances at 1, 3, 6, 9 and 12 months. One year after transplantation, 89.6% of MP patients and 66.7% of CS group had creatinine clearance higher than 30mL/min/1.73m2, p=0.01. In the multivariate analysis, risk factors for worse graft function at 1 year were: donor age (OR 1.11 CI95% 1.01-1.22; p=0,03) and CS preservation (OR 6.52 CI 95% 1.46-29.08; p=0.01). Conclusions: The incidence of DGF was high and there were no statistical differences between the groups. The higher CIT in the MP group did not increase incidence of DGF. Patients in the MP group were hospitalized 7 days less than the CS group, although there was no statistical difference. Patient and graft survival were high one year after KT, no differences between groups. MP showed better graft function one year after KT.

Outcome Improvement for Hypothermic Machine Perfusion Versus Cold Storage for Kidneys From Cardiac Death Donors.

Organ shortage has led to an increased use of kidneys from cardiac death donors (DCDs), but controversies about the methods of organ preservation still exist. This study aims to compare the effect of machine perfusion (MP) and cold storage (CS) in protecting kidneys harvested from DCDs. 141 kidney pairs from DCDs between July 2010 and July 2015 were included in this randomized controlled study. One kidney from each donor was randomly assigned to MP and the contralateral kidney was assigned to CS. Delayed graft function (DGF) rate, resistance index of renal arteries, early renal function, and survival rates were used to estimate the effect of preservation. The results showed that MP decreased the rate of DGF from 33.3 to 22.0% (P = 0.033). Ultrasound of the kidneys within 48 h after transplantation showed that the resistance index of renal main artery (0.673 ± 0.063 vs. 0.793 ± 0.124, P < 0.001), sub segmental artery (0.66 ± 0.062 vs. 0.764 ± 0.077, P < 0.001) and interlobular artery (0.648 ± 0.056 vs. 0.745 ± 0.111, P = 0.023) were all significantly lower in the MP group than those in the CS group. Furthermore, compared to the CS group, in the first 7 days following transplantation, the median urine volume was significantly higher (4080 mL vs. 3000 mL, P = 0.047) in kidneys sustained using MP and the median serum creatinine was remarkably lower (180 µmol/L vs. 390 µmol/L, P = 0.024). More importantly, MP group had higher 1- and 3-year graft survival rates (98% vs. 93%, P = 0.026; 93% vs. 82%, P = 0.036, respectively). Hypothermic MP improved the outcomes of DCD kidney transplantation.

Randomized Trial of Machine Perfusion Versus Cold Storage in Recipients of Deceased Donor Kidney Transplants With High Incidence of Delayed Graft Function.

BackgroundThis study compared the use of static cold storage versus continuous hypothermic machine perfusion in a cohort of kidney transplant recipients at high risk for delayed graft function (DGF).MethodsIn this national, multicenter, and controlled trial, 80 pairs of kidneys recovered from brain-dead deceased donors were randomized to cold storage or machine perfusion, transplanted, and followed up for 12 months. The primary endpoint was the incidence of DGF. Secondary endpoints included the duration of DGF, hospital stay, primary nonfunction, estimated glomerular filtration rate, acute rejection, and allograft and patient survivals.ResultsMean cold ischemia time was high but not different between the 2 groups (25.6 ± 6.6 hours vs 25.05 ± 6.3 hours, 0.937). The incidence of DGF was lower in the machine perfusion compared with cold storage group (61% vs. 45%, P = 0.031). Machine perfusion was independently associated with a reduced risk of DGF (odds ratio, 0.49; 95% confidence interval, 0.26-0.95). Mean estimated glomerular filtration rate tended to be higher at day 28 (40.6 ± 19.9 mL/min per 1.73 m2 vs 49.0 ± 26.9 mL/min per 1.73 m2; P = 0.262) and 1 year (48.3 ± 19.8 mL/min per 1.73 m2 vs 54.4 ± 28.6 mL/min per 1.73 m2; P = 0.201) in the machine perfusion group. No differences in the incidence of acute rejection, primary nonfunction (0% vs 2.5%), graft loss (7.5% vs 10%), or death (8.8% vs 6.3%) were observed.ConclusionsIn this cohort of recipients of deceased donor kidneys with high mean cold ischemia time and high incidence of DGF, the use of continuous machine perfusion was associated with a reduced risk of DGF compared with the traditional cold storage preservation method.

Increased Expression of Aldehyde Dehydrogenase 2 Reduces Renal Cell Apoptosis During Ischemia/Reperfusion Injury After Hypothermic Machine Perfusion.

Hypothermic machine perfusion (MP) can reduce graft's injury after kidney transplantation; however, the mechanism has not been elucidated. In the past decade, many studies showed that aldehyde dehydrogenase 2 (ALDH2) is a protease which can inhibit cell apoptosis. Therefore, this study aims to explore whether ALDH2 takes part in reducing organ damage after MP. Eighteen healthy male New Zealand rabbits (12 weeks old, weight 3.0 ± 0.3 kg) were randomly divided into three groups: normal group, MP group, and cold storage (CS) group (n = 6). The left kidney of rabbits underwent warm ischemia for 35 min through clamping the left renal pedicle and then reperfusion for 1 h. Left kidneys were preserved by MP or CS (4°C for 4 h) in vivo followed by the right nephrectomy and 24-h reperfusion, and then the specimens and blood were collected. Finally, concentration of urine creatinine (Cr), blood urea nitrogen (BUN), and 4-HNE were tested. Renal apoptosis was detected by TUNEL staining, and the expression of ALDH2, cleaved-caspase 3, bcl-2/ bax, MAPK in renal tissue was detected by immunohistochemistry or Western blot; 24 h after surgery, the concentration of Cr in MP group was 355 ± 71μmol/L, in CS group was 511 ± 44 μmol/L (P < 0.05), while the BUN was 15.02 ± 2.34 mmol/L in MP group, 22.64 ± 3.58 mmol/L in CS group (P < 0.05). The rate of apoptosis and expression of cleaved caspase-3, p-P38, p-ERK, and p-JNK in MP group was significantly lower than that in CS group (P < 0.05), while expression of ALDH2 and bcl-2/bax in MP group was significantly higher than that in CS group (P < 0.05); expression of cleaved caspase-3 in both MP and CS group significantly increased as compared with that in normal group (P < 0.05). In conclusion, increased expression of ALDH2 can reduce the renal cell apoptosis through inhibiting MAPK pathway during ischemia/reperfusion injury (IRI) after hypothermic MP.

Machine Perfusion: Not Just for Marginal Kidney Donors

Interest in machine perfusion (MP) for donated kidneys has markedly increased in the past decade as a means to improve graft function, although the donor populations in which it should be applied have not yet been resolved. All adults undergoing de-novo isolated kidney transplantation from standard-criteria donors in the UNOS database 2005 to 2011 were reviewed with the primary endpoint of delayed graft function (DGF), defined as dialysis within seven days of transplantation, in those who received kidneys that underwent MP versus cold storage (CS) alone. Three methods were used to control for differences between groups. Multivariable logistic regression was performed, adjusting for donor and recipient characteristics significantly associated with DGF. Rates were also compared in a cohort of propensity-matched MP vs CS recipients. Finally, a paired-kidney study was performed, where one kidney underwent MP and the contralateral underwent CS. There were 36,323 patients, with unadjusted DGF rates of 18.6 per cent (n = 1830/9882) and 22.4 per cent (n = 5931/26,441; P < 0.001) in the MP vs CS groups, respectively. After multivariable analysis, the odds ratio for DGF in the MP group was 0.59 (P < 0.001) versus CS. In the propensity-matched cohort, there were 8929 patients each in the MP and CS groups. DGF occurred in 16.8 per cent of the MP group vs 25.3 per cent with CS (P < 0.001, OR 0.59). In the paired-kidney study, rates of DGF were 16.7 per cent vs 24.3 per cent (P < 0.001) in the 1665 recipients each in the MP versus CS groups (OR 0.6). In conclusion, machine perfusion is beneficial in reducing DGF even when standard donors are utilized, and thus should not be limited to marginal kidneys.

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.

Hypothermic continuous machine perfusion improves metabolic preservation and functional recovery in heart grafts

The number of heart transplants is decreasing due to organ shortage, yet the donor pool could be enlarged by improving graft preservation. Hypothermic machine perfusion (MP) has been shown to improve kidney, liver, or lung graft preservation. Sixteen pig hearts were recovered following cardioplegia and randomized to two different groups of 4-hour preservation using either static cold storage (CS) or MP (Modified LifePort© System, Organ Recovery Systems, Itasca, Il). The grafts then underwent reperfusion on a Langendorff for 60 min. Energetic metabolism was quantified at baseline, postpreservation, and postreperfusion by measuring lactate and high-energy phosphates. The contractility index (CI) was assessed both in vivo prior to cardioplegia and during reperfusion. Following reperfusion, the hearts preserved using CS exhibited higher lactate levels (56.63 ± 23.57 vs. 11.25 ± 3.92 μmol/g; P < 0.001), increased adenosine monophosphate/adenosine triphosphate (AMP/ATP) ratio (0.4 ± 0.23 vs. 0.04 ± 0.04; P < 0.001), and lower phosphocreatine/creatine (PCr/Cr) ratio (33.5 ± 12.6 vs. 55.3 ± 5.8; P <0.001). Coronary flow was similar in both groups during reperfusion (107 ± 9 vs. 125 + /-9 ml/100 g/min heart; P = ns). CI decreased in the CS group, yet being well-preserved in the MP group. Compared with CS, MP resulted in improved preservation of the energy state and more successful functional recovery of heart graft.

Hypothermic Machine Perfusion Improves Kidney Viability Through Alleviation of Vasospasm and Edema of Sertoli Cell and Renal Tubular Epithelial Cell.

Background: There has been some controversy whether hypothermic machine perfusion (MP) can reduce rate of delayed graft function (DGF) as compared with static cold storage, and the mechanism of MP remains not well understood. This study was aimed to research the preservation effect in clinical trial, and then to expound the mechanism of MP in basic research. Method: In the clinical trial, we randomly assigned one kidney from 50 donors after cardiac death (DCD) to MP and the other to cold storage (CS) to study clinical preservation effect. In the basic research, one kidney from 5 New Zealand rabbits was randomly assigned to MP and the other to CS, the morphological and histological changes were observed to explore the mechanism of MP by immunohistochemical detection and transmission electron microscopy (TEM). Results: MP decreased DGF rate (12%) as compared to CS (32%) in kidneys (P=0.016). Compared with those in CS group, expression of alpha smooth muscle actin (alpha-SMA) in vascular smooth muscle in MP group from DCD were significantly lower (P<0.001), and diameters of renal tubular epithelial cell (0.011±0.001mm) in MP group reduced when compared with CS (0.020±0.003mm) (P<0.001). To expound the mechanism of MP, basic research in rabbits showed that average diameters of arcuate artery in MP group (0.117±0.034mm) were bigger when compared with CS group (0.088±0.026mm) (P=0.007), MP reduced diameters of renal tubular epithelial cell (0.012±0.002mm) when compared with CS (0.018±0.002mm) (P<0.001), TEM showed that MP group had lighter degree of structure damage and edema of mitochondria of sertoli cell and renal tubular epithelial cell.Figure: No Caption available.Conclusion: DGF rate reduced and kidney viability improved in MP group due to the alleviation vasospasm and reduced edema of sertoli cell and renal tubular epithelial cell by maintaining mitochondria morphology.

Resuscitation of Marginal Hearts Using Ex Vivo Perfusion.

Introduction: Increasing the usage of hearts from marginal donors and from donors after circulatory death (DCD) has the potential to expand the donor pool. Such hearts may be resuscitated when subjected to ex vivo perfusion. In addition, this may provide an opportunity for viability testing prior to transplant. We describe a novel ex vivo perfusion system designed to reanimate porcine DCD hearts. The same system was subsequently tested using a human heart from a marginal brainstem-dead donor. Method: In the first phase of the study 23 porcine hearts were procured following circulatory death. All hearts were subjected to a period of primary warm ischemia followed by 120 minutes of hypothermic preservation. The period of hypothermic preservation was initially static cold storage (SCS); then oxygenated machine perfusion and finally a combination of static cold storage and oxygen persufflation via the coronary sinus. Ex vivo perfusion of the hearts was performed with a normothermic, oxygenated blood-based solution in our Langendorff system. In the second phase of the study the same system was used to perfuse a human heart from a marginal brainstem-dead donor. This donor had not met criteria for consideration of heart donation. Results: 15 of the 23 (65.2%) DCD porcine hearts reanimated following reperfusion on the ex vivo system. Reanimation was achieved with 63.6% (7/11) in the SCS group; 33.3% (2/6) in the machine perfusion group and 100% (6/6) in the persufflation group. The human heart was placed in the system after a cold ischemic period of 7 hours 4 minutes and perfused with a mid-thermic temperature solution for a further 2 hours 40 minutes to allow for correction of hyperkalemia before warming. The heart started to work after a further hour and then maintained until the experiment was terminated after a further two hours. Conclusion: The ex vivo perfusion system described can potentially resuscitate marginal hearts including those from DCD. The system devised in this study could also be used as a platform to functionally assess marginal human hearts. This mode of viability testing would be an essential step to determine suitability for transplant.

Gene network analysis of liver allografts preserved with machine perfusion (649.10)

Machine perfusion (MP) with a cell‐free oxygen carrier solution (CFOCS) was compared to cold static preservation (CSP) in a porcine model. Methods: Two groups of 6 animals underwent liver transplantation after 9 hours of cold ischemia time. Clinical and laboratorial data was obtained in additional to serial histological and electron microscopy analysis. Affymetrix gene‐arrays were performed on liver tissues from both groups. A cytokine profile was obtained from liver tissues and perfusate with Luminex. Additional metabolomics analysis (Metabolon) was performed. Results: The MP group had 100% survival and the CSP group had 33% survival. A significant (p&lt;0.004) benefit of MP was detected after 16 different variables were analyzed. Over‐expression of genes associated with general metabolic functions, anti‐inflammatory, regenerative and protective mechanisms against free radicals were observed in the MP group. Genes associated with hepatic system development and cellular proliferation were significantly up‐regulated in the MP group. Genes associated with critical metabolic networks were significantly down regulated in the CSP group compared to MP livers. The lipid metabolic pathway was up regulated in the CSP group. Signaling pathways that are critical for liver growth (NF‐kB, PI3K/AT, ErbB) were significantly up‐regulated in MP liver samples when compared to CSP group. INF‐α, IL‐1β, IL‐1RA, IL‐4, IL‐10, IL‐12p40, IL‐18 and TNF‐α showed significant differences between the groups in liver tissues analyzed during preservation. Ingenuity® pathway analysis of functional groups revealed that genes associated with liver damage were significantly down regulated in the MP group. The CSP group showed significant up‐regulation of genes associated with liver pathology when compared to the MP group. Conclusions: MP with a CFOCS up‐regulated a regenerative and prosurvival response when compared to CSP.Grant Funding Source: NIH GrantNo.CA35373,CA103958 &amp; Rangos Fund for Enhancement of Researchin Pathology.