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Background: The global incidence of liver diseases is rising, yet there remains a dearth of precise research models to mimic these diseases. The use of normothermic machine perfusion (NMP) to study diseased livers recovered from liver transplantation (LT) recipients presents a promising avenue. Accordingly, we have developed a machine perfusion system tailored specifically for the human whole diseased livers and present our experience from the NMP of diseased livers., Methods: Six diseased livers recovered from LT recipients with different diagnoses were collected. The diseased livers were connected to the machine perfusion system that circulated tailored perfusate, providing oxygen and nutrients. The pressure and flow of the system were recorded, and blood gas analysis and laboratory tests of perfusate and bile were examined to analyze the function of the diseased livers. Liver tissues before and after NMP were collected for histological analysis., Results: Experiments showed that the system maintained the diseased livers in a physiological state, ensuring stable hemodynamics and a suitable partial pressure of oxygen and carbon dioxide. The results of blood gas analysis and laboratory tests demonstrated a restoration and sustenance of metabolism with minimal damage. Notably, a majority of the diseased livers exhibited bile production continuously, signifying their vivid functional integrity. The pathological characteristics remained stable before and after NMP., Conclusion: We successfully established the machine perfusion system tailored specifically for diseased human whole livers. Through the application of this system, we have developed a novel in vitro model that faithfully recapitulates the main features of human liver disease. This model holds immense promise as an advanced disease modeling platform, offering profound insights into liver diseases and potential implications for research and therapeutic development., (© 2024 The Authors. Artificial Organs published by International Center for Artificial Organ and Transplantation (ICAOT) and Wiley Periodicals LLC.)

Background: Normothermic machine perfusion (NMP) allows for the assessment and resuscitation of ex-vivo human livers prior to transplantation. Commercially available NMP systems are closed circuits that accumulate metabolic waste and cytokines over time, potentially limiting organ preservation times. Dialysis has been proposed as a method to remove waste and excess fluid from such systems. This study aimed to demonstrate the utility of integrating dialysis into a commercially available system by quantifying solute removal., Methods: A dialysis filter was attached in parallel to a commercially available liver perfusion system. Three livers declined for transplantation were split before undergoing long-term NMP with blood using the modified system. During perfusion, dialysate flow rates were set in the range of 100-600 mL/h for short periods of time. At each flow rate, perfusate and spent dialysate samples were collected and analyzed for solute clearance., Results: The addition of dialysis to a commercial NMP system removed water-soluble waste and helped regulate electrolyte concentrations. Interleukin-6 was successfully removed from the perfusate. Solute clearance was proportional to dialysate flow rate. A guide for our perfusion setup was created for the appropriate selection of dialysis flow rates and duration based on real-time perfusate composition., Conclusions: Dialysis circuits can efficiently remove waste and regulate perfusate composition, and can be easily incorporated to improve the performance of commercially available systems. Quantification of the effect of dialysis on perfusate composition enables refined dialysis control to optimize electrolyte profiles and avoid the over- or under-correction of key solutes., (© 2024 The Authors. Artificial Organs published by International Center for Artificial Organ and Transplantation (ICAOT) and Wiley Periodicals LLC.)

The use of machine perfusion in solid organ transplantation has developed tremendously worldwide in recent years. Although the number of randomized controlled trials in the field of organ preservation is still limited, machine perfusion has been shown to be superior to static cold storage of donor organs. Various devices for clinical use with hypothermia or normothermia are already available for most organs. Whether and which perfusion strategy is superior to the others is the subject of current clinical research. This also applies to the further evaluation of possible synergistic effects in the sequential use of the various protocols. The common goal of all dynamic perfusion technologies is to optimize organ preservation between removal and transplantation. By testing the quality of marginal donor organs prior to transplantation, it should also be possible to use these organs without exposing the patient to increased risk. This can lead to a significant expansion of the donor pool. This is particularly important in Germany, where there is an ongoing shortage of organs and restrictive legislation regarding the expansion of the donor pool. Furthermore, the perfusion technology offers the possibility to serve as a platform for other ex situ and in situ therapies on isolated organs. In addition to the conditioning of pre-damaged organs for transplantation, this could lead to further applications in the context of targeted organ therapies and also to improved transplant logistics in the future., (© 2024. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Purpose of Review: With changing donor characteristics (advanced age, obesity), an increase in the use of extended criteria donor (ECD) livers in liver transplantation is seen. Machine perfusion allows graft viability assessment, but still many donor livers are considered nontransplantable. Besides being used as graft viability assessment tool, ex situ machine perfusion offers a platform for therapeutic strategies to ameliorate grafts prior to transplantation. This review describes the current landscape of graft repair during machine perfusion., Recent Findings: Explored anti-inflammatory therapies, including inflammasome inhibitors, hemoabsorption, and cellular therapies mitigate the inflammatory response and improve hepatic function. Cholangiocyte organoids show promise in repairing the damaged biliary tree. Defatting during normothermic machine perfusion shows a reduction of steatosis and improved hepatobiliary function compared to nontreated livers. Uptake of RNA interference therapies during machine perfusion paves the way for an additional treatment modality., Summary: The possibility to repair injured donor livers during ex situ machine perfusion might increase the utilization of ECD-livers. Application of defatting agents is currently explored in clinical trials, whereas other therapeutics require further research or optimization before entering clinical research., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.)

Context: Clinical adoption of ex situ liver perfusion is growing. While hypothermic perfusion protects against ischemia-reperfusion injury in marginal grafts, normothermic perfusion enables organ viability assessment and therefore selection of borderline grafts. The combination of hypothermic and normothermic perfusion, known as "cold-to-warm," may be the optimal sequence for organ preservation, but is difficult to achieve with most commercial perfusion systems. We developed an adaptable customized circuit allowing uninterrupted "cold-to-warm" perfusion and conducted preclinical studies on healthy porcine livers and discarded human livers to demonstrate the circuit's efficacy., Methods: In collaboration with bioengineers, we developed a customized circuit that adapts to extracorporeal circulation consoles used in cardiovascular surgery and includes a proprietary reservoir enabling easy perfusate change without interrupting perfusion. This preclinical study was conducted on porcine and human livers. Perfusion parameters (pressures, flows, oxygenation) and organ viability were monitored., Results: The customized circuit was adapted to a LivaNova S5® console, and the perfusions were flow-driven with real-time pressure monitoring. Ten porcine liver and 12 discarded human liver perfusions were performed during 14 to 18 h and 7 to 25 h, respectively. No hyperpressure was observed (porcine and human portal pressure 2-6 and 2-8 mm Hg; arterial pressure 10-65 and 20-65 mm Hg, respectively). No severe histological tissue injury was observed (Suzuki score ≤ 3 at the end of perfusion). Seven (70%) porcine livers and five (42%) human livers met the UK viability criteria., Conclusion: The customized circuit and system design enables smooth uninterrupted "cold-to-warm" perfusion not present in current commercial perfusion systems., (© 2024 International Center for Artificial Organ and Transplantation (ICAOT) and Wiley Periodicals LLC.)

Background: Portable ex vivo lung perfusion during lung transplantation is a resource-intensive technology. In light of its increasing use, we evaluated the cost-effectiveness of ex vivo lung perfusion at a low-volume lung transplant center in the USA., Methods: Patients listed for lung transplantation (2015-2021) in the United Network for Organ Sharing database were included. Quality-of-life was approximated by Karnofsky Performance Status scores 1-year post-transplant. Total transplantation encounter and 1-year follow-up costs accrued by our academic center for patients listed from 2018 to 2021 were obtained. Cost-effectiveness was calculated by evaluating the number of patients attaining various Karnofsky scores relative to cost., Results: Of the 13 930 adult patients who underwent lung transplant in the United Network for Organ Sharing database, 13 477 (96.7%) used static cold storage and 453 (3.3%) used ex vivo lung perfusion, compared to 30/58 (51.7%) and 28/58 (48.3%), respectively, at our center. Compared to static cold storage, median total costs at 1 year were higher for ex vivo lung perfusion ($918 000 vs. $516 000; p = 0.007) along with the cost of living 1 year with a Karnofsky functional status of 100 after transplant ($1 290 000 vs. $841 000). In simulated scenarios, each Karnofsky-adjusted life year gained by ex vivo lung perfusion was 1.00-1.72 times more expensive., Conclusions: Portable ex vivo lung perfusion is not currently cost-effective at a low-volume transplant centers in the USA, being 1.53 times more expensive per Karnofsky-adjusted life year. Improving donor lung and/or recipient biology during ex vivo lung perfusion may improve its utility for routine transplantation., (© 2024 The Author(s). Artificial Organs published by International Center for Artificial Organ and Transplantation (ICAOT) and Wiley Periodicals LLC.)

The global lack of donor shortage poses a major limitation for heart transplantation. New concepts with expanded donor inclusion criteria comprise extended transport distances and prolonged ischemic times with the aim of reaching a larger number of potential donors. Recent developments in cold storage solutions may allow more donor hearts with prolonged ischemic times to be use for transplantation in the future. We present our experience during a long-distance donor heart procurement with the longest reported transport distance and transport time in the current literature. This was made possible through the use of SherpaPak™, an innovative cold storage system which allows for controlled temperatures during transportation., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Split liver transplantation is a valuable means of mitigating organ scarcity but requires significant surgical and logistical effort. Ex vivo splitting is associated with prolonged cold ischemia, with potentially negative effects on organ viability. Machine perfusion can mitigate the effects of ischemia-reperfusion injury by restoring cellular energy and improving outcomes., Methods: We describe a novel technique of full-left/full-right liver splitting, with splitting and reconstruction of the vena cava and middle hepatic vein, with dual arterial and portal hypothermic oxygenated machine perfusion. The accompanying video depicts the main surgical passages, notably the splitting of the vena cava and middle hepatic vein, the parenchymal transection, and the venous reconstruction., Results: The left graft was allocated to a pediatric patient having methylmalonic aciduria, whereas the right graft was allocated to an adult patient affected by hepatocellular carcinoma and cirrhosis., Conclusions: This technique allows ex situ splitting, counterbalancing prolonged ischemia with the positive effects of hypothermic oxygenated machine perfusion on graft viability. The venous outflow is preserved, safeguarding both grafts from venous congestion; all reconstructions can be performed ex situ, minimizing warm ischemia. Moreover, there is no need for highly skilled surgeons to reach the donor hospital, thereby simplifying logistical aspects., Competing Interests: The authors declare no funding or conflicts of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Normothermic machine perfusion (NMP) has been proposed to preserve liver grafts in a less pro-inflammatory environment. However, the effect of NMP on liver inflammation remains unclear. Therefore, we aimed at characterizing the inflammatory response during continuous NMP with a comprehensive investigation of cytokine release during perfusion., Methods: Ten porcine livers underwent either 24 h NMP or whole blood-based NMP (WB-NMP) immediately after procurement. WB-NMP was used as a positive control to mimic early post-reperfusion inflammation. High mobility group box-1 (HMGB1), interleukin 1-beta (IL-1beta), tumor necrosis factor-alpha (TNFalpha), interleukin 6 (IL-6), 8 (IL-8), and 10 (IL-10), transforming growth factor-beta (TGFbeta), aspartate transferase (AST), and hyaluronic acid were measured in the perfusate. The area under the curve (AUC) of their perfusate concentration was compared between groups. Median (IQR) is given., Results: The AUC of HMGB1 and IL-1beta was similar between groups. Compared to WB-NMP, NMP inhibited the release of TNFalpha [NMP: 20275 (18402-32 152), WB-NMP: 242100 (203511-244 238); p = 0.01], IL-6 [NMP: 1206 (338.9-1686), WB-NMP: 8444 (7359-10 087); p = 0.03], and IL-8 [NMP: 1635 (106.90-2130), WB-NMP: 3951 (3090-4116); p = 0.008]. The release of TGFbeta remained unchanged but IL-10 release was lower in NMP [1612 (1313-1916), WB-NMP: 5591 (4312-6421); p = 0.01]. The ratios TGFbeta:TNFalpha and IL-10:TNFalpha were significantly higher in the NMP than in the WB-NMP group. Importantly, the AUC of AST was significantly lower during NMP [1960 (1950-2893)] than WB-NMP [6812 (6370-7916); p = 0.02]., Conclusions: Continuous NMP leads to the release of detectable levels of cytokines with a slow, linear increase over time and a shift toward anti-inflammatory signaling., (© 2024 International Center for Artificial Organ and Transplantation (ICAOT) and Wiley Periodicals LLC.)

Organs cryopreserved by vitrification are exposed to the lowest possible concentration of cryoprotectants for the least time necessary to successfully avoid ice formation. Faster cooling and warming rates enable lower concentrations and perfusion times, reducing toxicity. Since warming rates necessary to avoid ice formation during recovery from vitrification are typically faster than cooling rates necessary for vitrification, warming speed is a major determining factor for successful vitrification. Dielectric warming uses an oscillating electric field to directly heat water and cryoprotectant molecules inside organs to achieve warming that's faster and more uniform than can be achieved by heat conduction from the organ surface. This work studied 27 MHz dielectric warming of rabbit kidneys perfused with M22 vitrification solution. The 27 MHz frequency was chosen because its long wavelength and penetration depth are suitable for human organs, because it had an anticipated favorable temperature of maximum dielectric absorption in M22, and because it's an allocated frequency for industrial and amateur use with inexpensive amplifiers available. Previously vitrified kidneys were warmed from -100 °C by placement in a 27 MHz electric field formed between parallel capacitor plates in a resonant circuit. Power was varied during warming to maintain constant electric field amplitude between the plates. Maximum power absorption occurred near -70 °C, with a peak warming rate near 150 °C/min in 50 mL total volume with approximately 500 W power. After some optimization, it was possible to warm ∼13 g vitrified kidneys with unprecedentedly little injury from medullary ice formation and a favorable serum creatinine trend after transplant. Distinct behaviors of power absorption and system tuning observed as a function of temperature during warming are promising for non-invasive thermometry and future automated control of the warming process at even faster rates with user-defined temperature dependence., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: The persistent shortage of liver allografts contributes to significant waitlist mortality despite efforts to increase organ donation. Normothermic machine perfusion holds the potential to enhance graft preservation, extend viability, and allow liver function evaluation in organs previously discarded because considered too high-risk for transplant., Methods: Discarded livers from other transplant centers were transplanted after assessment and reconditioning with our institutionally developed normothermic machine perfusion device. We report here our preliminary data., Results: Twenty-one human livers declined for transplantation were enrolled for assessment with normothermic machine perfusion. Six livers (28.5%) were ultimately discarded after normothermic machine perfusion because of insufficient lactate clearance (>4.1 mmol/L after 4 hours), limited bile production (<0.5 mI/h), or moderate macrosteatosis, whereas 15 (71.5%) were considered suitable for transplantation. Normothermic machine perfusion duration was from 3 hours, 49 minutes to 10 hours, 29 minutes without technical problems or adverse events. No intraoperative or major early postoperative complications occurred in all transplanted recipients. No primary nonfunction occurred after transplantation. Seven livers had early allograft dysfunction with fast recovery, and 1 patient developed ischemic cholangiopathy after 4 months treated with biliary stents. All other patients had good liver function with a follow-up time of 8 weeks to 14 months., Conclusion: In total, 71.5% of discarded livers subjected to ex vivo normothermic machine perfusion were successfully transplanted after organ perfusion and assessment using an institutionally built device. This study challenges the current viability criteria reported in the literature and calls for a standardization of viability markers collection, an essential condition for the advancement of the field., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: There is a continued interest in ex situ heart perfusion as an alternative strategy for donor heart preservation. We hypothesize that oxygenated machine perfusion of donor hearts at a temperature that avoids both normothermia and deep hypothermia offers adequate and safe preservation., Methods: Cardioplegia-arrested porcine donor hearts were randomly assigned to six hours of preservation using cold storage (CS, n = 5) or machine perfusion using an oxygenated acellular perfusate at 21°C (MP, n = 5). Subsequently, all grafts were evaluated using the Langendorff method for 120 min. Metabolic parameters and histology were analyzed. Systolic function was assessed by contractility and elastance. Diastolic function was assessed by lusitropy and stiffness., Results: For both groups, in vivo baseline and post-Langendorff biopsies were comparable, as were lactate difference and myocardial oxygen consumption. Injury markers gradually increased and were comparable. Significant weight gain was seen in MP (p = 0.008). Diastolic function was not impaired in MP, and lusitropy was superior from 30 min up to 90 min of reperfusion. Contractility was superior in MP during the first hour of evaluation., Conclusion: We conclude that the initial functional outcome of MP-preserved hearts was transiently superior compared to CS, with no histological injury post-Langendorff. Our machine perfusion strategy could offer feasible and safe storage of hearts prior to transplantation. Future studies are warranted for further optimization., (© 2021 The Authors. Artificial Organs published by International Center for Artificial Organ and Transplantation (ICAOT) and Wiley Periodicals LLC.)

No single reliable parameter exists to assess liver graft function of extended criteria donors during ex-vivo normothermic machine perfusion (NMP). The liver maximum capacity (LiMAx) test is a clinically validated cytochromal breath test, measuring liver function based on 13CO2 production. As an innovative concept, we aimed to integrate the LiMAx breath test with NMP to assess organ function. Eleven human livers were perfused using NMP. After one hour of stabilization, LiMAx testing was performed. Injury markers (ALT, AST, miR-122, FMN, and Suzuki-score) and lactate clearance were measured and related to LiMAx values. LiMAx values ranged between 111 and 1838 µg/kg/h, and performing consecutive LiMAx tests during longer NMP was feasible. No correlation was found between LiMAx value and miR-122 and FMN levels in the perfusate. However, a significant inverse correlation was found between LiMAx value and histological injury (Suzuki-score, R = - 0.874, P < 0.001), AST (R = - 0.812, P = 0.004) and ALT (R = - 0.687, P = 0.028). Furthermore, a significant correlation was found with lactate clearance (R = 0.683, P = 0.043). We demonstrate, as proof of principle, that liver function during NMP can be quantified using the LiMAx test, illustrating a positive correlation with traditional injury markers. This new breath-test application separates livers with adequate cytochromal liver function from inadequate ones and may support decision-making in the safe utilization of extended criteria donor grafts., (© 2021. The Author(s).)

The advantages of oxygenated perfusion are continuing to be demonstrated by many groups focused on improving the efficacy of tissue preservation for transplant, bioreactors for studies of basic tissue physiology, and closed-loop resuscitation. This work presents a novel and portable device that supplies oxygenated and pulsatile perfusion, both of which are regulated by a single pump-oxygenator component comprised of silicone tubes that are cyclically inflated/deflated with compressed oxygen. In this study, pump variables (oxygen supply pressure and length of a silicone tube) were evaluated against hydraulic elements that mimicked the vascular resistance of kidneys, livers, and hearts. The perfusion pressures, flow rates, and oxygenation rates produced by the device were characterized for all configurations of pump variables, and the pulse rates were tuned to improve performance. The device supplied perfusion pressures ranging from 3.5 to 109 mmHg, flow rates ranging from 1.4 to 71.8 mL min -1 , and oxygenation rates up to 316.6 µmol min -1 . From those results, it was determined that the device was capable of achieving perfusion parameters used in previous kidney, liver, and heart preservation studies. Ultimately, this research demonstrated the efficacy of a novel device that is designed to supply oxygenated perfusion across a range of applications., (© 2021. Biomedical Engineering Society.)

Objective: The aim of this study was to evaluate peak serum alanine aminotransferase (ALT) and postoperative clinical outcomes after hypothermic oxygenated machine perfusion (HOPE) versus static cold storage (SCS) in extended criteria donation (ECD) liver transplantation (LT) from donation after brain death (DBD)., Background: HOPE might improve outcomes in LT, particularly in high-risk settings such as ECD organs after DBD, but this hypothesis has not yet been tested in a randomized controlled clinical trial (RCT)., Methods: Between September 2017 and September 2020, 46 patients undergoing ECD-DBD LT from four centers were randomly assigned to HOPE (n = 23) or SCS (n = 23). Peak-ALT levels within 7 days following LT constituted the primary endpoint. Secondary endpoints included incidence of postoperative complications [Clavien-Dindo classification (CD), Comprehensive Complication Index (CCI)], length of intensive care- (ICU) and hospital-stay, and incidence of early allograft dysfunction (EAD)., Results: Demographics were equally distributed between both groups [donor age: 72 (IQR: 59-78) years, recipient age: 62 (IQR: 55-65) years, labMELD: 15 (IQR: 9-25), 38 male and 8 female recipients]. HOPE resulted in a 47% decrease in serum peak ALT [418 (IQR: 221-828) vs 796 (IQR: 477-1195) IU/L, P = 0.030], a significant reduction in 90-day complications [44% vs 74% CD grade ≥3, P = 0.036; 32 (IQR: 12-56) vs 52 (IQR: 35-98) CCI, P = 0.021], and shorter ICU- and hospital-stays [5 (IQR: 4-8) vs 8 (IQR: 5-18) days, P = 0.045; 20 (IQR: 16-27) vs 36 (IQR: 23-62) days, P = 0.002] compared to SCS. A trend toward reduced EAD was observed for HOPE (17% vs 35%; P = 0.314)., Conclusion: This multicenter RCT demonstrates that HOPE, in comparison to SCS, significantly reduces early allograft injury and improves post-transplant outcomes in ECD-DBD liver transplantation., Competing Interests: The authors report no conflicts of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Given the susceptibility of organs to ischaemic injury, alternative preservation methods to static cold storage (SCS), such as normothermic machine perfusion (NMP) are emerging. The aim of this study was to perform a comparison between NMP and SCS in liver transplantation with particular attention to bile duct lesions., Methods: The outcomes of 59 consecutive NMP-preserved donor livers were compared in a 1 : 1 propensity score-matched fashion to SCS control livers. Postoperative complications, patient survival, graft survival and bile duct lesions were analysed., Results: While patients were matched for cold ischaemia time, the total preservation time was significantly longer in the NMP group (21 h versus 7 h, P < 0.001). Patient and graft survival rates at 1 year were 81 versus 82 per cent (P = 0.347) and 81 versus 79 per cent (P = 0.784) in the NMP and SCS groups, respectively. The postoperative complication rate was comparable (P = 0.086); 37 per cent NMP versus 34 per cent SCS patients had a Clavien-Dindo grade IIIb or above complication. There was no difference in early (30 days or less) (NMP 22 versus SCS 19 per cent, P = 0.647) and late (more than 30 days) (NMP 27 versus SCS 36 per cent, P = 0.321) biliary complications. However, NMP-preserved livers developed significantly fewer ischaemic-type bile duct lesions (NMP 3 versus SCS 14 per cent, P = 0.047)., Conclusion: The use of NMP allowed for a significantly prolonged organ preservation with a lower rate of observed ischaemic-type bile duct lesions., (© The Author(s) 2021. Published by Oxford University Press on behalf of BJS Society Ltd. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Competing Interests: The authors declare no funding or conflicts of interest.

Donation after circulatory death (DCD) grafts are commonly used in liver transplantation. Attributable to the additional ischemic event during the donor warm ischemia time (DWIT), DCD grafts carry an increased risk for severe ischemia/reperfusion injury and postoperative complications, such as ischemic cholangiopathy. The actual ischemia during DWIT depends on the course of vital parameters after withdrawal of life support and varies widely between donors. The ischemic period (functional DWIT) starts when either Spo2 or blood pressure drop below a certain point and lasts until the start of cold perfusion during organ retrieval. Over the years, multiple definitions and thresholds of functional DWIT duration have been used. The International Liver Transplantation Society organized a Consensus Conference on DCD, Liver Preservation, and Machine Perfusion on January 31, 2020 in Venice, Italy. The aim of this conference was to reach consensus about various aspects of DCD liver transplantation in context of currently available evidence. Here we present the recommendations with regards to the definitions used for DWIT and functional DWIT, the importance of vital parameters after withdrawal of life support, and acceptable thresholds of duration of functional DWIT to proceed with liver transplantation., Competing Interests: The authors declare no funding or conflicts of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

In deceased donor kidney transplantation (KT), a prolonged cold ischemia time (CIT) is a negative prognostic factor for KT outcome, and the efficacy of hypothermic machine perfusion (HMP) in prolonging CIT without any additional hazard is highly debated. We conducted a retrospective study on a cohort of 154 single graft deceased donor KTs, in which a delayed HMP, after a preliminary period of static cold storage (SCS), was used to prolong CIT for logistic reasons. Primary outcomes were postoperative complications as well as 1 year graft survival and function. 73 cases (47.4%) were managed with HMP and planned KT, while 81 (52.6%) with SCS and urgent KT. The median CIT in HMP group and SCS group was 29 hour:57 minutes [27-31 hour:45 minutes] and 11 hour:25 minutes [9-14 hour:30 minutes], respectively (P < .001). The period of SCS in the HMP group was significantly shorter than in the SCS group (10 vs. 11 hour:25 minutes, P = .02) as well as the prevalence of expanded criteria donors was significantly higher (43.8% vs. 18.5%, P < .01). After propensity score matching for these two baseline characteristics, the HMP and SCS groups showed comparable outcomes in terms of delayed graft function, vascular, and urologic complications, infections, and episodes of graft rejection. At 1 year follow-up, serum creatinine levels were comparable between the groups. Therefore, the use of HMP to prolong the CIT and convert KT into a planned procedure seemed to have an adequate safety profile, with outcomes comparable to KT managed as an urgent procedure and a CIT nearly three time shorter., (© 2020 International Center for Artificial Organs and Transplantation and Wiley Periodicals LLC.)

In the Netherlands, the average quality of donor organs continues to decrease as a result of the increasing life expectancy, as well as higher incidence of obesity, diabetes mellitus, and other comorbidities in the general population. Storing donor organs on ice, the current standard practice, appears to be inadequate for preserving these high-risk donor livers. Consequently, an increasing number of donor organs is discarded for transplantation. Over the past years, a novel dynamic preservation technique using a machine perfusion device has been developed. Preservation by machine perfusion enables optimisation and viability testing of high-risk donor livers prior to liver transplantation. A large proportion of initially declined donor livers appeared to be suitable for transplantation after evaluation during machine perfusion. Testing of donor livers has led to a significant increase in the number of liver transplantations performed in the Netherlands. This technique has the potential for use in other organs, such as kidney allografts.

Nowadays, liver transplantation is the most effective treatment for end-stage liver disease. However, the increasing imbalance between growing demand for liver transplantation and the shortage of donor pool restricts the development of liver transplantation. How to expand the donor pool is a significant problem to be solved clinically. Many doctors have devoted themselves to marginal grafting, which introduces livers with barely passable quality but a high risk of transplant failure into the donor pool. However, existing common methods of preserving marginal grafts lead to both high risk of postoperative complications and high mortality. The application of machine perfusion allows surgeons to make marginal livers meet the standard criteria for transplant, which shows promising prospect in preserving and repairing donor livers and improving ischemia reperfusion injury. This review summarizes the progress of recent researches on hepatic machine perfusion., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

The possible reno-protective effect of a controlled brief heat-shock treatment during isolated ex vivo machine perfusion of donor grafts prior to reperfusion should be investigated in a primary in vitro study. Porcine kidneys (n = 14) were retrieved after 20 minutes of cardiac standstill of the donor and subjected to 20 hours of static cold storage in University of Wisconsin solution. Prior to reperfusion, kidneys were subjected to 2 hours of reconditioning machine perfusion with gradual increase in perfusion temperature up to 35°C. In half of the kidneys (n = 7), a brief hyperthermic impulse (10 minutes perfusion at 42°C) was implemented in the machine perfusion period. Functional recovery of the grafts was observed upon normothermic reperfusion in vitro. Hyperthermic treatment resulted in a 50% increase of heat shock protein (HSP) 70 and HSP 27 mRNA and was accompanied by ~ 50% improvement of tubular re-absorption of sodium and glucose upon reperfusion, compared with the controls. Furthermore, renal loss of aspartate aminotransferase was significantly reduced to one-third of the controls as was urinary protein loss, evaluated by the albumin to creatinine ratio. It is concluded that ex vivo heat-shock treatment seems to be an easily implementable and promising option to enhance renal self-defense machinery against reperfusion injury after preservation that merits further investigation in preclinical models., (© 2020 The Authors. Clinical and Translational Science published by Wiley Periodicals LLC on behalf of the American Society for Clinical Pharmacology and Therapeutics.)

End-stage renal disease is a major global health burden. The only definitive treatment existing is renal transplantation. Worldwide, the demand for donated kidneys by far exceeds the supply. A novel technique for organ preservation, normothermic machine perfusion (NMP), now promises to increase the potential pool of available organs by extending the spectrum of donors and reducing the incidence of graft failure. First studies in humans and large animals are being performed with promising results, but refinement of the technique, buffer, and machines involved is labor-intensive and expensive. To our knowledge, this is the first report of a small animal model of NMP and subsequent transplantation., (© 2020 The Authors. Artificial Organs published by International Center for Artificial Organ and Transplantation and Wiley Periodicals LLC.)

Background: The 5-year graft survival rate of donor kidneys transplanted in the Eurotransplant Senior Program (ESP) is only 47 per cent. Normothermic machine perfusion (NMP) may be a new preservation technique that improves graft outcome. This pilot study aimed to assess safety and feasibility of this technique within the ESP., Methods: Recipients were eligible for inclusion if they received a donor kidney within the ESP. Donor kidneys underwent 2 h of oxygenated NMP with a red cell-based solution at 37°C, additional to standard-of-care preservation (non-oxygenated hypothermic machine perfusion). The primary outcome was the safety and feasibility of NMP. As a secondary outcome, graft outcome was investigated and compared with that in a historical group of patients in the ESP and the contralateral kidneys., Results: Eleven patients were included in the NMP group; the function of eight kidneys could be compared with that of the contralateral kidney. Fifty-three patients in the ESP, transplanted consecutively between 2016 and 2018, were included as controls. No adverse events were noted, especially no arterial thrombosis or primary non-function of the transplants. After 120 min of oxygenated NMP, median flow increased from 117 (i.q.r. 80-126) to 215 (170-276) ml/min (P = 0.001). The incidence of immediate function was 64 per cent in the NMP group and 40 per cent in historical controls (P = 0.144). A significant difference in graft outcome was not observed., Discussion: This pilot study showed NMP to be safe and feasible in kidneys transplanted in the ESP. A well powered study is warranted to confirm these results and investigate the potential advantages of NMP on graft outcome., (© The Author(s) 2021. Published by Oxford University Press on behalf of BJS Society Ltd.)

Ex vivo lung perfusion (EVLP) allows the ventilation and perfusion of lungs to evaluate their viability for transplantation. The aim of this study is to compare the mechanical, morphologic and functional properties of lungs during EVLP with values obtained in vivo to guide a safe mechanical ventilation strategy. Lungs from 5 healthy pigs were studied in vivo and during 4 hours of EVLP. Lung compliance, airway resistance, gas exchange, and hemodynamic parameters were collected at positive end-expiratory pressure (PEEP) of 5 cm H 2 O. Computed tomography was performed at PEEP 0, PEEP 5, and total lung capacity (TLC). Lung pressure-volume (PV) curves were performed from PEEP 0 to TLC. Lung compliance decreased during EVLP (53 ± 5 mL/cm H 2 O vs 29 ± 7 mL/cm H 2 O, P < .05), and the PV curve showed a lower inflection point. Gas content (528 ± 118 mL vs 892 ± 402 mL at PEEP 0) and airway resistance (25 ± 5 vs 44 ± 9 cmH 2 O/L∗s -1 , P < .05) were higher during EVLP. Alveolar dead space (5% ± 2% vs 17% ± 6%, P < .05) and intrapulmonary shunt (9% ± 2% vs 28% ± 13%, P < .05) increased ex vivo compared to in vivo, while the partial pressure of oxygen to inspired oxygen fraction ratio (PO 2 /FiO 2 ) did not differ (468 ± 52 mm Hg vs 536 ± 14 mm Hg). In conclusion, during EVLP lungs show signs of air trapping and bronchoconstriction, resulting in low compliance and increased alveolar dead space. Intrapulmonary shunt is high despite oxygenation levels acceptable for transplantation., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Demand for heart transplants far exceeds supply of donated organs. This is attributed to the high percentage of donor hearts that are discarded and to the narrow six-hour time window currently available for transplantation. Ex-vivo heart perfusion (EVHP) provides the opportunity for resuscitation of damaged organs and extended transplantation time window by enabling functional assessment of the hearts in a near-physiologic state. Present work investigates the fluid mechanics of the ex-vivo flow loop and corresponding impact on cardiac performance. A mechanical flow loop is developed that is analogous to the region of the EVHP system that mimics in-vivo systemic circulation, including the body's largest and most compliant artery, the aorta. This investigation is focused on determining the effect of mock aortic tubing compliance on pump performance. A custom-made silicone mock aorta was developed to simulate a range of in-vivo conditions and a physiological flow was generated using a commercial ventricular assist device (VAD). Monitored parameters, including pressure, tube distension and downstream velocity, acquired using time-resolved particle imaging velocimetry (PIV), were applied to an unsteady Bernoulli analysis of the flow in a novel way to evaluate pump performance as a proxy for cardiac workload. When compared to the rigid case, the compliant mock aorta case demonstrated healthier physiologic pressure waveforms, steadier downstream flow and reduced energetic demands on the pump. These results provide experimental verification of Windkessel theory and support the need for a compliant mock aorta in the EVHP system., Competing Interests: The authors have declared that no competing interests exist.

Background: The role of machine perfusion (MP) in the evaluation of liver grafts with macrovesicular steatosis (MaS) remains ill-defined as only a limited number of studies has been reported. The objective of the current study was to provide a systematic review to evaluate the role of MP in the setting of MaS livers., Methods: A systematic review, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was performed. Eligible articles published up to April 2019 were included using the MEDLINE, Scopus, and Google Scholar databases., Results: Among the 422 articles screened, only 16 papers met the inclusion criteria. A total of 54 cases of MP use before liver transplantation were included. Sixteen (29.6%) grafts were from donors after circulatory death. In 22 (40.7%) cases, hypothermic machine perfusion was performed. Normothermic machine perfusion was done in the remaining 32 (59.3%) cases. According to the histological results of the donor core biopsy, a MaS value < 30% was observed in 41 (75.9%) cases, whereas 13 (24.1%) patients had moderate-to-severe (≥ 30%) MaS. Following categorization of the pooled population according to the presence of moderate-to-severe (≥ 30%) MaS in the donor graft, no differences were noted in terms of post-transplant death or severe complications following MP. There was no correlation between the proportion of MaS in the donor graft relative to post-transplant peak ALT among patients treated with MP. Among the entire pooled cohort, there was also no correlation between MaS values and ALT peak (R = 0.13; P = 0.42)., Conclusions: MP appears to be feasible and safe in MaS livers. Experience to date has been very limited, and the benefit of MP remains not determined. Prospective studies will need to define better the potential effect of "defatting" drugs used during the perfusion process on MaS.

Hypothermic machine perfusion (HMP) is a method that can be more effective in preserving donor organs compared with cold storage (CS). However, the optimal duration and the exact mechanisms of the protevtive effects of HMP remain unknow. The present study aimed to investigate the adequate perfusion time and mechanisms underlying HMP to protect livers donated after circulatory death (DCD). After circulatory death, adult male Sprague‑Dawley rat livers were subjected to 30 min of warm ischemia (WI) and were subsequently preserved by HMP or CS. To determine the optimal perfusion time, liver tissues were analyzed at 0, 1, 3, 5, 12 and 24 h post‑preservation to evaluate injury and assess the expression of relevant proteins. WI livers were preserved by HMP or CS for 3 h, and liver viability was evaluated by normothermic reperfusion (NR). During NR, oxygen consumption, bile production and the activities of hepatic enzymes in the perfusate were assessed. Following 2 h of NR, levels of inflammation and oxidative stress were determined in the livers and perfusate. HMP for 3 h resulted in the highest expression of myocyte enhancer factor 2C (MEF2C) and kruppel‑like factor 2 (KLF2) and the lowest expression of NF‑κB p65, tumor necrosis factor (TNF)‑α and interleukin (IL)‑1β among the different timepoints, which indicated that 3 h may be the optimal time for HMP induction of the KLF2‑dependent signaling pathway. Compared with CS‑preserved livers, HMP‑preserved livers displayed significantly higher oxygen consumption, lower hepatic enzyme levels in the perfusate following NR. Following HMP preservation, the expression levels of MEF2C, KLF2, endothelial nitric oxide synthase and nitric oxide were increased, whereas the expression levels of NF‑κB p65, IL‑1β and TNF‑α were decreased compared with CS preservation. The results indicated that 3 h may be the optimal time for HMP to protect DCD rat livers. Furthermore, HMP may significantly reduce liver inflammation and oxidative stress injury by mediating the KLF2/NF‑κB/eNOS‑dependent signaling pathway.

Background: Combined liver-kidney transplantation (CLKT) improves survival for liver transplant recipients with renal dysfunction; however, the tenuous perioperative hemodynamic and metabolic milieu in high-acuity CLKT recipients increases delayed graft function and kidney allograft failure. We sought to analyze whether delayed KT through pumping would improve kidney outcomes following CLKT., Methods: A retrospective analysis (University of California Los Angeles [n = 145], Houston Methodist Hospital [n = 79]) was performed in all adults receiving CLKT at 2 high-volume transplant centers from February 2004 to January 2017, and recipients were analyzed for patient and allograft survival as well as renal outcomes following CLKT., Results: A total of 63 patients (28.1%) underwent delayed implantation of pumped kidneys during CLKT (dCLKT) and 161 patients (71.9%) received early implantation of nonpumped kidneys during CLKT (eCLKT). Most recipients were high-acuity with median biologic model of end-stage liver disease (MELD) score of, 35 for dCLKT and 34 for eCLKT (P = ns). Pretransplant, dCLKT had longer intensive care unit stay, were more often intubated, and had greater vasopressor use. Despite this, dCLKT exhibited improved 1-, 3-, and 5-year patient and kidney survival (P = 0.02) and decreased length of stay (P = 0.001), kidney allograft failure (P = 0.012), and dialysis duration (P = 0.031). This reduced kidney allograft futility (death or continued need for hemodialysis within 3 mo posttransplant) for dCLKT (6.3%) compared with eCLKT (19.9%) (P = 0.013)., Conclusions: Delayed implantation of pumped kidneys is associated with improved patient and renal allograft survival and decreased hospital length of stay despite longer kidney cold ischemia. These data should inform the ethical debate as to the futility of performing CLKT in high-acuity recipients.

The 25th Annual Congress of the International Liver Transplantation Society was held in Toronto, Canada, from May 15 to 18, 2019. Surgeons, hepatologists, anesthesiologists, critical care intensivists, radiologists, pathologists, and research scientists from all over the world came together with the common aim of improving care and outcomes for liver transplant recipients and living donors. Some of the featured topics at this year's conference included multidisciplinary perioperative care in liver transplantation, worldwide approaches to organ allocation, donor steatosis, and updates in pediatrics, immunology, and radiology. This report presents excerpts and highlights from invited lectures and select abstracts, reviewed and compiled by the Vanguard Committee of International Liver Transplantation Society. This will hopefully contribute to further advances in clinical practice and research in liver transplantation.

Background: Herpetic keratitis (HK) models using whole human corneas are essential for studying virus-host relationships, because of high species specificity and the role of interactions between corneal cell populations that cell culture cannot reproduce. Nevertheless, the two current corneal storage methods (hypothermia and organ culture (OC)) do not preserve corneas in good physiological condition, as they are characterized by epithelial abrasion, stromal oedema, and excessive endothelial mortality., Methods: To rehabilitate human corneas intended for scientific use, we used an active storage machine (ASM) that restores two physiological parameters that are essential for corneal homeostasis: intraocular pressure and storage medium renewal (21mmHg and 2.6 μL/min, respectively). ASM storage regenerates a normal multilayer epithelium in 2 weeks. We infected six pairs of corneas unsuitable for graft by inoculating the epithelium with herpes simplex virus type 1 (HSV-1), and compared each ASM-stored cornea with the other cornea stored in the same medium using the conventional OC method., Results: Only corneas in the ASM developed a dendritic (n = 3) or geographic (n = 2) epithelial ulcer reproducing typical HSV-1-induced clinical lesions. Corneas in OC showed only extensive desquamations. None of the uninfected controls showed epithelial damage. Histology, immunohistochemistry, transmission electron microscopy and polymerase chain reaction on corneal tissue confirmed infection in all cases (excluding negative controls)., Conclusions: The ASM provides an innovative ex vivo model of HK in whole human cornea that reproduces typical epithelial lesions., Competing Interests: Please note that PG and GT are inventors of the active storage machine on “patent US 20160029618A1” submitted by Jean Monnet University that covers “Medical device intended for long-term storage of a cornea, or for ex vivo experimentation on a human or animal cornea”. The other authors have no proprietary or commercial interest in any materials discussed in this article."I can confirm that this does not alter our adherence to PLOS ONE policies on sharing data and materials.

Pancreatic static cold storage (SCS) is the gold-standard method for pancreas preservation. Our main objective was to evaluate feasibility of hypothermic perfusion (HP) of nonhuman primates' pancreases for potential organ transplantation. Seven baboon pancreases were tested. Animals were included in a study approved by the French Research Ministry of Health. Two groups were compared: the control group (n = 2) was preserved using conventional SCS for 24-h and the perfusion group (n = 5) used HP for 24-h, with three different perfusion pressures (PP): 15 (n = 3), 20 (n = 1), and 25 mm Hg (n = 1). In the control group, focal congestion of islets was observed after 6-h. At 24-h, ischemic necrosis and multifocal congestion also occurred. In the HP group, at 15 mm Hg PP, multifocal congestion of islets was present at 24-h. At 20 mm Hg PP, no ischemic necrosis was found after 6-h. At 12-h and 24-h, focal congestion of islets was seen. At 25 mm Hg PP, focal congestion of islets appeared after 12-h. Immunostaining for insulin, glucagon, and somatostatin was normal and similar in controls and perfused pancreas transplants even after 24-h. Apoptosis index represented by cleaved caspase 3 activity, was less than 1% in perfusion and control groups, even after 24-h. HP of nonhuman primate pancreas is feasible and not deleterious as far as 24-h compared to SCS. SCS for more than 12-h was harmful for the transplants. Systolic perfusion pressure between 15-20 mm Hg did not cause any pathological injury of the tested organs., (© 2020 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.)

There is a need to improve the quality of donor liver from donation after circulatory death (DCD). The purpose of this study was to investigate the effects and mechanism of normothermic machine perfusion (NMP) combined with bone marrow mesenchymal stem cells (BMMSCs) on the oxidative stress and mitochondrial function in DCD livers. DCD livers were obtained, a rat NMP system was established, and BMMSCs were extracted and identified. The DCD livers were grouped by their preservation method: Normal, static cold storage (SCS), NMP (P), and NMP combined with BMMSCs (PB), and the preservation time was up to 8 h. An IAR20 cell oxidative stress injury model was established in vitro by simulating DCD oxidative stress injury and coculturing with BMMSCs for 6 h. Compared with SCS group, after 6 h in vitro, the PB and P groups had significantly improved liver function and liver histological damage, reduced hepatocyte apoptosis and oxidative stress, improved hepatocyte mitochondrial damage, and increased mitochondrial membrane potential. These indicators were significantly better in the PB group than in the P group. BMMSCs significantly inhibited reactive oxygen species release from the IAR20 cell oxidative stress model in vitro, ameliorated mitochondrial damage, and increased mitochondrial membrane potential level. BMMSCs also downregulated the JUN N-terminal kinase-nuclear factor kappa B (JNK-NF-κB) signaling pathway significantly in the IAR20 cell oxidative stress model and promoted AMP-activated protein kinase (AMPK) activation. We verified that NMP combined with BMMSCs also played the same role in the PB group. NMP combined with BMMSCs could improve liver quality by relieving oxidative stress injury and improving mitochondrial function in rat DCD livers. The mechanism of protective role might involve inhibiting the JNK-NF-κB pathway to reduce oxidative stress and promote AMPK activation, thereby reducing mitochondrial damage and increase mitochondrial function.

Background: Corneal storage for the very long term, without degradation, would make it possible to optimize a very limited resource worldwide. We previously demonstrated the superiority, compared to conventional 4-week passive organ culture (OC), of an active storage machine (ASM) that restores intraocular pressure and medium renewal. Here, we investigate eye banking for up to 3 months., Methods: In a randomized preclinical trial with 24 paired corneas, 1 was stored in OC and the other in ASM, using the same medium. Assessments were done on the second day and at 3 months: endothelial cell density (ECD in cells/mm), corneal transparency and thickness. At day 86, OC corneas were deswelled in a common hyperosmotic medium, but not the ASM corneas, which had remained thin. In addition, at day 88, viable ECD was measured using a live/dead assay, and endothelial expression of Na/K ATPase, Cox IV, ZO-1, N-CAM, and CD166 was observed., Results: The ASM extended storage to 3 months with unprecedented endothelial cell quality: no OC corneas remained suitable for transplantation, but one-third of ASM corneas were compliant (ECD > 2000/mm). Given that corneas with ECD > 1600/mm were also usable for emergency, 58% of ASM corneas were usable versus 33% in OC. EC survival was 53% higher in ASM (P < 0.001), structural and functional proteins of ECs were much better preserved in ASM, and it prevented the constant major edema of OC., Conclusions: By extending graft survival to 3 months, the ASM will optimize eye banking and open up new perspectives in experimental research.

Preservation of human organs at subzero temperatures has been an elusive goal for decades. The major complication hindering successful subzero preservation is the formation of ice at temperatures below freezing. Supercooling, or subzero non-freezing, preservation completely avoids ice formation at subzero temperatures. We previously showed that rat livers can be viably preserved three times longer by supercooling as compared to hypothermic preservation at +4 °C. Scalability of supercooling preservation to human organs was intrinsically limited because of volume-dependent stochastic ice formation at subzero temperatures. However, we recently adapted the rat preservation approach so it could be applied to larger organs. Here, we describe a supercooling protocol that averts freezing of human livers by minimizing air-liquid interfaces as favorable sites of ice nucleation and uses preconditioning with cryoprotective agents to depress the freezing point of the liver tissue. Human livers are homogeneously preconditioned during multiple machine perfusion stages at different temperatures. Including preparation, the protocol takes 31 h to complete. Using this protocol, human livers can be stored free of ice at -4 °C, which substantially extends the ex vivo life of the organ. To our knowledge, this is the first detailed protocol describing how to perform subzero preservation of human organs.

Background: The Institut Georges Lopez 1 (IGL-1) solution was developed to improve the outcomes of solid organ transplantation. Nevertheless, follow-up of liver transplants using IGL-1-preserved organs is still scarce., Aim: To compare morbidity, postoperative complications, and early survival between liver grafts perfused with IGL-1 and those perfused with histidine-tryptophan-ketoglutarate (HTK) solutions., Methods: Prospective liver grafts perfused with IGL-1 (n = 65) were paired with a historical control group of recipients whose grafts were preserved with HTK solution (n = 130). The primary endpoint was the sum of the incidence of primary graft dysfunction (PGD) and primary graft nonfunction (PGNF). Secondary endpoints included resource utilization, complications, and survival analysis., Results: In the HTK group, 52 patients (40%) exhibited either PGD or PGNF, compared to 20 patients (31%) in the IGL-1 group (P = .208). Patients from the HTK group had higher mean values for cryoprecipitate transfusion (P = .0064), first day serum lactate (P = .0099), higher incidence of vascular complications (11% vs 2% in the IGL-1 group; P = .0226), but a lower incidence of infection (7% vs 28% in the IGL-1 group; P < .0001). The IGL-1 group presented a lower mean aspartate aminotransferase and alanine aminotransferase (ALT) on the first and second postoperative day and a lower ALT on the seventh day. Recipients of grafts perfused with IGL-1 had a better early survival than those whose grafts were perfused with HTK., Conclusions: Both solutions are safe and present good results. Grafts perfused with IGL-1 showed decreased enzymatic peaks and better short-term survival rates than the HTK group. The use of the IGL-1 solution might be preferable., (Copyright © 2020 Elsevier Inc. All rights reserved.)

There is a significant organ shortage in the field of liver transplantation, partly due to a high discard rate of steatotic livers from donors. These organs are known to function poorly if transplanted but make up a significant portion of the available pool of donated livers. This study demonstrates the ability to improve the function of steatotic rat livers using a combination of ex situ machine perfusion and a "defatting" drug cocktail. After 6 hours of perfusion, defatted livers demonstrated lower perfusate lactate levels and improved bile quality as demonstrated by higher bile bicarbonate and lower bile lactate. Furthermore, defatting was associated with decreased gene expression of pro-inflammatory cytokines and increased expression of enzymes involved in mitochondrial fatty acid oxidation. Rehabilitation of marginal or discarded steatotic livers using machine perfusion and tailored drug therapy can significantly increase the supply of donor livers for transplantation., Competing Interests: Dr. Uygun is inventor on pending patents relevant to this study (WO/2011/002926; WO/2011/35223) and has a provisional patent application relevant to this study (MGH 22743). Dr. Uygun has a financial interest in Organ Solutions, a company focused on developing organ preservation technology. Dr. Uygun’s interests are managed by the MGH and Partners HealthCare in accordance with their conflict of interest policies. This does not alter our adherence to PLOS ONE policies on sharing data and materials”.

With the aim to explore innovative tools for organ preservation, especially in marginal organs, we hereby describe a clinical trial of ex-vivo hypothermic oxygenated perfusion (HOPE) in the field of liver (LT) and kidney transplantation (KT) from Extended Criteria Donors (ECD) after brain death. A matched-case analysis of donor and recipient variables was developed: 10 HOPE-ECD livers and kidneys (HOPE-L and HOPE-K) were matched 1:3 with livers and kidneys preserved with static cold storage (SCS-L and SCS-K). HOPE and SCS groups resulted with similar basal characteristics, both for recipients and donors. Cumulative liver and kidney graft dysfunction were 10% (HOPE L-K) vs. 31.7%, in SCS group (p = 0.05). Primary non-function was 3.3% for SCS-L vs. 0% for HOPE-L. No primary non-function was reported in HOPE-K and SCS-K. Median peak aspartate aminotransferase within 7-days post-LT was significantly higher in SCS-L when compared to HOPE-L (637 vs.344 U/L, p = 0.007). Graft survival at 1-year post-transplant was 93.3% for SCS-L vs. 100% of HOPE-L and 90% for SCS-K vs. 100% of HOPE-K. Clinical outcomes support our hypothesis of machine perfusion being a safe and effective system to reduce ischemic preservation injuries in KT and in LT.

Background: Heart transplantation is the most effective treatment for people experiencing end-stage heart failure whose quality of life and life expectancy are unacceptable. However, there is a chronic shortage of donor hearts to meet the demand, so it is essential to expand the donor pool and increase supply. Heart donation mainly occurs after brain death (neurological determination of death [NDD]), but it may also be feasible after cardiocirculatory death (when the heart has stopped beating and there is no longer blood flow or a pulse), provided specialized preservation techniques are used. An investigational device, a portable normothermic cardiac perfusion system, could make it possible to procure, preserve, and transport hearts donated after cardiocirculatory death (DCD). We conducted a health technology assessment of a portable normothermic cardiac perfusion system for the preservation and transportation of DCD hearts for adult transplantation. This included an evaluation of the effectiveness, safety, value for money, and budget impact of publicly funding this system, as well as an evaluation of patient preferences and values., Methods: We performed a systematic review of the clinical literature published since 1998 that examined the clinical safety and effectiveness of a portable normothermic cardiac perfusion system for DCD heart transplantation. We assessed the risk of bias of each included study and the quality of the body of evidence according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. We also reviewed the economic evidence published during the same time period for the cost-effectiveness of a portable normothermic cardiac perfusion system for DCD hearts compared with cold storage for NDD hearts. We further estimated the 5-year net budget impact of publicly funding a normothermic cardiac perfusion system for DCD heart transplantation for adults on Ontario's waitlist. To contextualize the potential value of a portable normothermic cardiac perfusion system, we spoke with people waiting for a heart transplant, people who had received a heart transplant, and family members of organ donors., Results: We screened 2,386 clinical citations. One study and two case reports met the inclusion criteria. The survival of recipients of DCD hearts procured with a portable normothermic cardiac perfusion system did not differ significantly from the survival of recipients of hearts donated after NDD at 30 days or 90 days, nor was there a significant difference in cumulative survival at 1 year post-transplant (GRADE: Very Low). The occurrence of rejection and graft failure also did not significantly differ between the groups (GRADE: Very Low). Cardiac function in the early post-operative period was better in DCD hearts than NDD hearts (GRADE: Very Low). There were no differences in outcomes between DCD procurement techniques.The economic literature search yielded 62 citations. One report met the inclusion criteria but was not directly applicable to the Ontario context. Given the lack of clinical and economic evidence on long-term outcomes, we did not conduct a primary economic evaluation. In the budget impact analysis, based on the number of DCD donors under 40 years of age in the last 5 years, we estimated that the increased availability of donor hearts made possible by the technology would result in an additional seven transplants in year 1, increasing to 12 in year 5. The annual net budget impact of publicly funding a normothermic cardiac perfusion system for the transplantation of DCD hearts in Ontario over the next 5 years is about $2.0 million in the first year and about $0.9 million in each of years 2 through 5, yielding a total net budget impact of about $5.6 million. This number increases to about $10.3 million if the transplant volume increases to 18 hearts in year 1 (meaning a subsequent increase of up to 21 hearts in year 5). If transplantation were limited to people who do not qualify for a ventricular assistive device or who qualify but do not wish to receive one, the total 5-year net budget impact would be about $7.9 million.People waiting for a heart transplant or who had received a heart transplant and family members of organ donors expressed no substantial concerns about the potential use of a portable normothermic cardiac perfusion system. They hope that it may increase the number of donor hearts available for transplant. For family members of organ donors, a perfusion system may provide comfort and value if it can increase the successful procurement of donor hearts., Conclusions: Based on very low quality of evidence, the outcomes for recipients of DCD hearts preserved using a portable normothermic cardiac perfusion system appear to be similar to outcomes for recipients of NDD hearts. Owing to a lack of evidence relevant to the Ontario context, we were unable to determine whether a portable normothermic perfusion system may be cost-effective. We estimate that publicly funding a portable normothermic cardiac perfusion system for DCD heart transplantation over the next 5 years will cost about $5.6 million. The people we spoke with believe that the system may increase the number of hearts available for transplant and therefore increase the number of heart transplants that can be done., (Copyright © Queen's Printer for Ontario, 2020.)

Background: The optimal method of oxygen delivery to donor kidneys during ex vivo machine perfusion has not been established. We have recently reported the beneficial effects of subnormothermic (22°C) blood perfusion in the preservation of porcine donation after circulatory death kidneys. Since using blood as a clinical perfusate has limitations, including matching availability and potential presence of pathogen, we sought to assess hemoglobin-based oxygen carrier (HBOC-201) in oxygen delivery to the kidney for renal protection., Methods: Pig kidneys (n = 5) were procured after 30 minutes of warm in situ ischemia by cross-clamping the renal arteries. Organs were flushed with histidine tryptophan ketoglutarate solution and subjected to static cold storage or pulsatile perfusion with an RM3 pump at 22°C for 4 hours with HBOC-201 and blood. Thereafter, kidneys were reperfused with normothermic (37°C) oxygenated blood for 4 hours. Blood and urine were subjected to biochemical analysis. Total urine output, urinary protein, albumin/creatinine ratio, flow rate, resistance were measured. Acute tubular necrosis, apoptosis, urinary kidney damage markers, neutrophil gelatinase-associated lipocalin 1, and interleukin 6 were also assessed., Results: HBOC-201 achieved tissues oxygen saturation equivalent to blood. Furthermore, upon reperfusion, HBOC-201 treated kidneys had similar renal blood flow and function compared with blood-treated kidneys. Histologically, HBOC-201 and blood-perfused kidneys had vastly reduced acute tubular necrosis scores and degrees of terminal deoxynucleotidyl transferase 2'-deoxyuridine, 5'-triphosphate nick end labeling staining versus kidneys treated with cold storage. Urinary damage markers and IL6 levels were similarly reduced by both blood and HBOC-201., Conclusions: HBOC-201 is an excellent alternative to blood as an oxygen-carrying molecule in an ex vivo subnormothermic machine perfusion platform in kidneys.

Ex vivo testing is a fundamental step in the development of new medical devices; indeed without it, it is impossible to proceed with in vivo tests. At the University of Florence, a robotic tool for microwave thermal ablation is under development. Up to now, the thermoablation tests for the validation of the tool were carried out on non-perfused ex vivo livers, providing results that inevitably differ from those obtainable with an in vivo liver. The aim is to design, and consequently create, a compact and transportable system which allows to perfuse a swine liver with physiological solution and heparin. This device should also allow the organ to be transported from the explantation place to the laboratory, keeping it under normothermal condition. The perfusor was designed to simulate the physiological flow within the liver in the most realistic way possible. The design, construction, and optimization of the perfusor have been addressed using the physiological values of hepatic flow and pressure identified in the literature, neglecting in the first instance any load losses. Therefore, open circuit tests were conducted, validated through perfusion tests on freshly explanted pig liver; during these tests, the surface temperature of the organ was recorded using an infrared camera, and the fluid temperature was verified using an immersion probe. The perfusion test showed a good alignment with the open circuit tests, demonstrating the validity of the simplifications adopted to treat the complex vascular structure of the liver.

The criteria for donor organ acceptance are broadening. We describe a successful lung transplantation following donation after circulatory death of extended criteria donor supported with biventricular assist devices. During the redo sternotomy, we used the biventricular assist devices cannulae to perfuse the lungs through the pulmonary artery cannula and draining via the left and right ventricle cannula, significantly minimizing the ischaemic time. Following procurement, we utilized portable ex vivo lung system (Transmedics™ Lung OCS) to optimize, assess and eventually to proceed to a successful transplant., (© The Author(s) 2019. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)