Human Anterior Segment Perfusion Organ Culture.

The human anterior segment perfusion organ culture is an ex vivo model system for studying the human conventional outflow pathway with reference to pressure regulation. In this model, anterior segments dissected from human donor eyes can be fixed to a modified petri dish and perfused with media along with various study agents at the physiological flow rate of 2.5 µL/min. The model mimics the one-way flow of aqueous humor in human eyes and can be used to evaluate the effects of various drugs on eye pressure in real time. Using this model, cells and tissues of the anterior segment can be maintained for up to 28 days, enabling histological and molecular evaluations.

Human Corneal Rim Perfusion Culture.

Human anterior segment perfusion cultures are frequently used for trabecular meshwork research. However, this model requires the use of whole eye globes which are expensive. Here, we describe a method using human corneal rims as an alternative to anterior segments for perfusion culture. In this method, the human corneal rim is glued to a three-dimensional-printed perfusion plates instead of using mechanical compression in traditional perfusion culture setup. The corneal rim and perfusion plate are placed onto a special holder for perfusion culture. This method is affordable and easy to set up. The instruments for traditional perfusion culture studies can be used for this model without modification.

Microdialysis perfusion of COA-Cl enhances dopamine metabolism in the dorsal striatum of freely moving mice.

We performed a microdialysis study to examine the effects of local perfusion of COA­Cl on the extracellular levels of dopamine (DA) and its metabolites in the dorsal striatum of mice in vivo. The mice were perfused with Ringer's solution (control) and COA­Cl (0.05, 0.1, or 0.5 mM) into the dorsal striatum. Dialysate samples were collected every 30 min and then analyzed using high­performance liquid chromatography coupled with an electrochemical detector. We found that local perfusion of COA­Cl (0.1 or 0.5 mM) into the dorsal striatum of living mice produced a significant and dose­dependent increase in extracellular levels of DA, 3­methoxytyramine (3­MT), and homovanillic acid (HVA), where only 0.5 mM COA­Cl increased dihydroxyphenylacetic acid (DOPAC) levels. However, 0.05 mM of COA­Cl did not significantly affect either DA levels or its metabolites. Then, we administered the monoamine oxidase (MAO) inhibitor clorgyline alone or in combination with COA­Cl (0.1 mM) to test whether COA­Cl­induced increases in DOPAC and HVA are mediated by increased MAO activity. Clorgyline alone increased 3­MT levels and decreased DOPAC and HVA levels but not DA levels. When combined with COA­Cl, clorgyline increased 3­MT levels and reversed the decrease in DOPAC and HVA levels caused by clorgyline. The increase in DA metabolism induced by COA­Cl suggests that some DA was further metabolized into DOPAC, 3­MT, and HVA. This indicates that COA­Cl plays a role in DA metabolism via increased DA release and/or activation of MAO, offering new insights into the effects of COA­Cl on DA metabolism in the brain.

Assessing Biomarkers of Porcine Kidneys under Normothermic Machine Perfusion-Can We Gain Insight into a Marginal Organ?

To identify potentially transplantable organs in a pool of marginal kidneys, 33 porcine slaughterhouse kidneys were perfused for 4 h with whole blood. During the normothermic perfusion, plasma, urine, and tissue samples were taken. Several biomarkers for tubule injury, endothelial activation, and inflammatory response were evaluated for a potential correlation with macroscopic appearance, histology, and filtration activity. Generally, biomarker levels increased during perfusion. TLR-4, EDN-1, and NGAL were not associated with any classification. In contrast, a steeper increase in NAG and IL-6 in plasma correlated with a poor macroscopic appearance at 4 h, indicating a higher inflammatory response in the kidneys with worse macroscopy early on, potentially due to more damage at the tubules. Although long-term effects on the graft could not be assessed in this setting, early observation under machine perfusion with whole blood was feasible. It allowed the assessment of kidneys under conditions comparable to reperfusion. This setting could give surgeons further insight into the quality of marginal kidneys and an opportunity to pre-treat them.

Hypothermic Oxygenated machine PErfusion for high-risk liver grafts for transplantation: A systematic review and meta-analysis.

BACKGROUND: Hypothermic Oxygenated machine PErfusion (HOPE) can reduce ischemic reperfusion injury and improve outcomes for liver transplant recipients. However, the effect of HOPE on high-risk extended criteria donor (ECD) and donation after circulatory death determination (DCDD) grafts is incomplete, despite the expectation that this cohort benefit maximally from HOPE. Accordingly, this paper aims to characterize the effect of HOPE on ECD and DCDD grafts. METHODS: This study includes all papers comparing HOPE to static cold storage for high-risk ECD and DCDD grafts. Systematic searches of Medline, Embase, and Scopus were completed using the terms "HOPE" OR "hypothermic oxygenated machine perfusion" AND "liver transplantation". Data were extracted and analyzed using IBM SPSS to perform the meta-analysis. RESULTS: A total of 2286 records were identified, with 10 meeting the inclusion criteria. Overall, the quality of evidence is heterogenous with many papers relying on retrospective controls. However, pooled analysis demonstrates HOPE to significantly reduce the rate of early allograft dysfunction, 12-month graft failure, re-transplantation, total biliary complications, and non-anastomotic strictures for high-risk grafts. CONCLUSIONS: There is good evidence that HOPE improves outcomes following liver transplantation across a number of biochemical and clinical endpoints for high-risk grafts. Of note, the reduction in biliary complications and re-transplantation is particularly significant given the morbidity associated with these endpoints. However, further, high-quality prospective trials with contemporary controls and clinically relevant primary endpoints are needed to better define the impact of HOPE for this cohort of grafts.

Dynamic culture of cerebral organoids using a pillar/perfusion plate for the assessment of developmental neurotoxicity.

Despite the potential toxicity of commercial chemicals to the development of the nervous system (known as developmental neurotoxicity or DNT), conventionalin vitrocell models have primarily been employed for the assessment of acute neuronal toxicity. On the other hand, animal models used for the assessment of DNT are not physiologically relevant due to the heterogenic difference between humans and animals. In addition, animal models are low-throughput, time-consuming, expensive, and ethically questionable. Recently, human brain organoids have emerged as a promising alternative to assess the detrimental effects of chemicals on the developing brain. However, conventional organoid culture systems have several technical limitations including low throughput, lack of reproducibility, insufficient maturity of organoids, and the formation of the necrotic core due to limited diffusion of nutrients and oxygen. To address these issues and establish predictive DNT models, cerebral organoids were differentiated in a dynamic condition in a unique pillar/perfusion plate, which were exposed to test compounds to evaluate DNT potential. The pillar/perfusion plate facilitated uniform, dynamic culture of cerebral organoids with improved proliferation and maturity by rapid, bidirectional flow generated on a digital rocker. Day 9 cerebral organoids in the pillar/perfusion plate were exposed to ascorbic acid (DNT negative) and methylmercury (DNT positive) in a dynamic condition for 1 and 3 weeks, and changes in organoid morphology and neural gene expression were measured to determine DNT potential. As expected, ascorbic acid did not induce any changes in organoid morphology and neural gene expression. However, exposure of day 9 cerebral organoids to methylmercury resulted in significant changes in organoid morphology and neural gene expression. Interestingly, methylmercury did not induce adverse changes in cerebral organoids in a static condition, thus highlighting the importance of dynamic organoid culture in DNT assessment.

Normothermic Regional Perfusion Experience of Organ Procurement Organizations in the US.

Importance: Despite the unmet need for donor organs, organ use from donation after circulatory determination of death (DCD) donors has been limited by inferior transplant outcomes. Normothermic regional perfusion (NRP) improves recipient outcomes and organ utilization from DCD donors. There is variability in NRP policies and experience among US organ procurement organizations (OPOs). Objectives: To determine OPO experience, identify operational inconsistencies, and explore needs related to NRP. Design, Setting, and Participants: This survey study included 55 OPOs in the US that had recovered DCD organs and completed a survey on operational, administrative, and educational components related to NRP in November to December 2023. Data analysis was performed from February to April 2024. Main Outcome and Measures: The primary outcome was the number of OPOs participating in and/or anticipating NRP participation. Secondary outcomes were NRP implementation barriers, OPO education practices, and future needs regarding consensus NRP recommendations and standards. Results: Of 55 respondents, 11 (20%) were chief executive officers, 8 (15%) were chief operating officers, and 36 (65%) were medical directors or chief clinical officers. Forty-nine OPOs facilitated NRP cases: 26 OPOs (53%) facilitated both thoracoabdominal NRP (TA-NRP) and abdominal NRP (A-NRP) cases, 16 OPOs (33%) facilitated only TA-NRP, and 7 OPOs (14%) facilitated only A-NRP. OPOs reported 606 NRP cases (421 TA-NRP [69%], 185 A-NRP [31%]); median (range) case experience was 8 (1-52). Fifty-two of 55 OPOs (95%) thought standardized guidance documents would be helpful. All 49 OPOs facilitated NRP at a transplant center's request; 39 (80%) had NRP initiated by a nonlocal transplant center. Twenty-three of 49 OPOs (47%) participated in NRP without a policy and without a policy pending approval. Positive donor hospital feedback was received by 29 OPOs (59%), primarily focused on increased organs transplanted and prerecovery communication. Allocation challenges were experienced by 21 OPOs (43%); their median (range) case volume was higher than those with no reported allocation challenges (11 [3-52] vs 6.5 [1-29]; P = .03). Eleven OPOs (22%) had incorporated NRP into general donor hospital education. Conclusions: In this survey study of US OPOs, wide variation existed with respect to NRP experience and practice. Allocation challenges occurred more frequently with increased NRP experience. NRP guidelines and standardization were desired by most OPOs to decrease allocation challenges and maximize the gift of organ donation.

Changing Landscape of Open Offers in Liver Transplantation in the Machine Perfusion Era: Exposure, Equity, and Economics.

BACKGROUND: Open offers (OOs) in liver transplantation (LT) result from bypassing the traditional allocation system. Little is known about the trends of OOs or the differences in donor/recipient characteristics compared to traditionally placed organs. We aim to quantify modern practices regarding OOs and understand NMP's impact, focusing on social determinants of health (SDH), cost, and graft-associated risk. METHODS: LTs from 1/1/2018 to 12/31/2023 at a single center were included. NMP was implemented on 10/1/2022. The CDC (centers for disease control)-validated social vulnerability index (SVI) and donor risk index (DRI) were calculated. Comprehensive complications index (CCI), Clavien-Dindo grades, patient and graft survival, and costs of transplantation were included. RESULTS: 1162 LTs were performed; 193 (16.8%) from OOs. OOs were more common in the post-NMP era (26.5% vs. 13.3%, p < 0.001). Pre-NMP, patients receiving OOs had longer waitlist times (118 vs. 69 days, p < 0.001), lower MELDs (17 vs. 25 points, p < 0.001), and riskier grafts (DRI = 1.8 vs. 1.6, p = 0.004) compared to standard offers. Post-NMP, recipients receiving OOs demonstrated no difference in waitlist time (27 vs. 20 days, p = 0.21) or graft risk (DRI = 2.03 vs. 2.23, p = 0.17). OO recipient MELD remained lower (16 vs. 22, p < 0.001). OO recipients were more socially vulnerable (SVI), pre-NMP (0.41 vs. 0.36, p = 0.004), but less vulnerable after NMP (0.23 vs. 0.36, p = 0.019). Despite increased graft risk, pre-NMP OO-LTs were less expensive in the 90-day global period ($154 939 vs. $178 970, p = 0.002) and the 180-days pre-/post-LT ($208 807 vs. $228 091, p = 0.021). Cost trends remained similar with NMP. CONCLUSION: OOs are increasingly utilized and may be appealing due to demonstrated cost reductions even with NMP. Although most OO-related metrics in our center remain similar before and after machine perfusion, programs should take caution that increasing use does not worsen organ access for socially vulnerable populations.

Ex vivo evaluation of the whole heart function allowing selective investigation of the right and left heart.

Objectives. The aim was to demonstrate a reliable ex vivo method to test the function of the whole heart. Design. Pigs of varying sizes (44-80 kg) were exposed to dose response of adrenaline. Blood pressures and cardiac output were measured. The explanted hearts were tested in a novel ex vivo system to see if we could replicate the in vivo values at maximal adrenaline stimulation. The perfusion solution was STEEN Solution™ with erythrocytes and continuous infusion of essential drugs. In contrast to normal body circulation which is sequential, the heart evaluation system is divided into left and right heart circuits which are operating in parallel, making it possible to test the right and left heart individually or as a whole. The system provides coronary flow measurements. The nonlinear dynamic resistances are constructed to stabilize systolic and diastolic pressures in a broad range and independently from cardiac output. It is important for the functional evaluation to avoid pumping help for the heart; therefore, atrial vortexes are constructed to minimize pump flow directionality and energy from entering atria. Results. Ex vivo evaluation was able to match the maximal in vivo effect of adrenaline on cardiac output and blood pressures. After 2 h of evaluation, the blood gases and lactate were normal and free haemoglobin was zero. Autopsy of the hearts showed no macroscopic pathology. Conclusions. The system is able to give a reliable functional evaluation of the heart ex vivo.

Cardioprotection by Preconditioning with Intralipid Is Sustained in a Model of Endothelial Dysfunction for Isolated-Perfused Hearts.

Endothelial dysfunction (ED) is closely associated with most cardiovascular diseases. Experimental models are needed to analyze the potential impact of ED on cardioprotection in constant pressure Langendorff systems (CPLS). One cardioprotective strategy against ischemia/reperfusion injury (I/RI) is conditioning with the lipid emulsion Intralipid (IL). Whether ED modulates the cardioprotective effect of IL remains unknown. The aim of the study was to transfer a protocol using a constant flow Langendorff system for the induction of ED into a CPLS, without the loss of smooth muscle cell functionality, and to analyze the cardioprotective effect of IL against I/RI under ED. In isolated hearts of male Wistar rats, ED was induced by 10 min perfusion of a Krebs-Henseleit buffer containing 60 mM KCl (K+), and the vasodilatory response to the vasodilators histamine (endothelial-dependent) and sodium-nitroprusside (SNP, endothelial-independent) was measured. A CPLS was employed to determine cardioprotection of pre- or postconditioning with 1% IL against I/RI. The constant flow perfusion of K+ reduced endothelial response to histamine but not to SNP, indicating reduced vasodilatory functionality of endothelial cells but not smooth muscle cells. Preconditioning with IL reduced infarct size and improved cardiac function while postconditioning with IL had no effect. The induction of ED neither influenced infarct size nor affected the cardioprotective effect by preconditioning with IL. This protocol allows for studies of cardioprotective strategies under ED in CLPS. The protection by preconditioning with IL seems to be mediated independently of a functional endothelium.

Low-Volume Ex Situ Lung Perfusion System for Single Lung Application in a Small Animal Model Enables Optimal Compliance With "Reduction" in 3R Principles of Animal Research.

Ex situ lung perfusion (ESLP) is used for organ reconditioning, repair, and re-evaluation prior to transplantation. Since valid preclinical animal models are required for translationally relevant studies, we developed a 17 mL low-volume ESLP for double- and single-lung application that enables cost-effective optimal compliance "reduction" of the 3R principles of animal research. In single-lung mode, ten Fischer344 and Lewis rat lungs were subjected to ESLP and static cold storage using STEEN or PerfadexPlus. Key perfusion parameters, thermal lung imaging, blood gas analysis (BGA), colloid oncotic pressure (COP), lung weight gain, histological work-up, and cytokine analysis were performed. Significant differences between perfusion solutions but not between the rat strains were detected. Most relevant perfusion parameters confirmed valid ESLP with homogeneous lung perfusion, evidenced by uniform lung surface temperature. BGA showed temperature-dependent metabolic activities with differences depending on perfusion solution composition. COP is not decisive for pulmonary oedema and associated weight gain, but possibly rather observed chemokine profile and dextran sensitivity of rats. Histological examination confirmed intact lung architecture without infarcts or hemorrhages due to optimal organ procurement and single-lung application protocol using our in-house-designed ESLP system.

A novel approach for perfusion process design based on a "Grey-Box" kinetic model.

Perfusion cell-culture mode has caught industrial interest in the field of biomanufacturing in recent years. Thanks to new technology, perfusion-culture processes can support higher cell densities, higher productivities and longer process times. However, due to the inherent operational complexity and high running costs, the development and design of perfusion-culture processes remain challenging. Here, we present a model-based approach to design optimized perfusion cultures of Chinese Hamster Ovary cells. Initially, four batches of bench-top reactor continuous-perfusion-culture data were used to fit the model parameters. Then, we proposed the model-based process design approach, aiming to quickly find out the "theoretically optimal" operational parameters combinations (perfusion rate and the proportion of feed medium in perfusion medium) which could achieve the target steady-state VCD while minimizing both medium cost and perfusion rate during steady state. Meanwhile, we proposed a model-based dynamic operational parameters-adjustment strategy to address the issue of cell-growth inhibition due to the high osmolality of concentrated perfusion medium. In addition, we employed a dynamic feedback control method to aid this strategy in preventing potential nutrient depletion scenarios. Finally, we test the feasibility of the model-based process design approach in both shake flask semi-perfusion culture (targeted at 5 × 107 cells/ml) and bench-top reactor continuous perfusion culture (targeted at 1.1 × 108 cells/ml). This approach significantly reduces the number of experiments needed for process design and development, thereby accelerating the advancement of perfusion-mode cell-culture processes.

Transcriptomic signatures during normothermic liver machine perfusion correspond with graft quality and predict the early graft function.

BACKGROUND: A better understanding of the molecular events during liver normothermic machine perfusion (NMP) is warranted to develop a data-based approach for the identification of biomarkers representative of graft quality and posttransplant outcome. We analysed the dynamic transcriptional changes during NMP and linked them to clinical and biochemical parameters. METHODS: 50 livers subjected to NMP for up to 24 h were enrolled. Bulk RNA sequencing was performed in serial biopsies collected pre and during NMP, and after reperfusion. Perfusate was sampled to monitor liver function. qPCR and immunohistochemistry were performed to validate findings. Molecular profiles were compared between transplanted and non-transplanted livers, and livers with and without early allograft dysfunction. FINDINGS: Pathways related to immune and cell stress responses, cell trafficking and cell regulation were activated during NMP, while cellular metabolism was downregulated over time. Anti-inflammatory responses and genes involved in tissue remodelling were induced at later time-points, suggesting a counter-response to the immediate damage. NMP strongly induced a gene signature associated with ischemia-reperfusion injury. A 7-gene signature corresponds with the benchmarking criteria for transplantation or discard at 6 h NMP (area under curve 0.99). CD274 gene expression (encoding programmed cell-death ligand-1) showed the highest predictive value. LEAP2 gene expression at 6 h NMP correlated with impaired graft function. INTERPRETATION: Assessment of gene expression markers could serve as a reliable tool to evaluate liver quality during NMP and predicts early graft function after transplantation. FUNDING: The research was supported by "In Memoriam Dr. Gabriel Salzner Stiftung", Tiroler Wissenschaftsfond, Jubiläumsfonds-Österreichische Nationalbank and MUI Start grant.

Ex-Vivo Human-Sized Organ Machine Perfusion: A Systematic Review on the Added Value of Medical Imaging for Organ Condition Assessment.

Machine perfused ex-vivo organs offer an excellent experimental platform, e.g., for studying organ physiology and for conducting pre-clinical trials for drug delivery. One main challenge in machine perfusion is the accurate assessment of organ condition. Assessment is often performed using viability markers, i.e., lactate concentrations and blood gas analysis. Nonetheless, existing markers for condition assessment can be inconclusive, and novel assessment methods remain of interest. Over the last decades, several imaging modalities have given unique insights into the assessment of organ condition. A systematic review was conducted according to accepted guidelines to evaluate these medical imaging methods, focussed on literature that use machine perfused human-sized organs, that determine organ condition with medical imaging. A total of 18 out of 1,465 studies were included that reported organ condition results in perfused hearts, kidneys, and livers, using both conventional viability markers and medical imaging. Laser speckle imaging, ultrasound, computed tomography, and magnetic resonance imaging were used to identify local ischemic regions and quantify intra-organ perfusion. A detailed investigation of metabolic activity was achieved using 31P magnetic resonance imaging and near-infrared spectroscopy. The current review shows that medical imaging is a powerful tool to assess organ condition.

Liver Graft Machine Perfusion: From History Perspective to Modern Approaches in Transplant Surgery.

The shortage of donor organs remains an unresolved issue in livertransplantation worldwide. Consequently, strategies for expanding the donor pool are currently being developed. Donors meeting extended criteria undergo thorough evaluation, as livers obtained from marginal donors yield poorer outcomes in recipients, including exacerbated reperfusion injury, acute kidney injury, early graft dysfunction, and primary nonfunctioning graft. However, the implementation of machine perfusion has shown excellent potential in preserving donor livers and improving their characteristics to achieve better outcomes for recipients. In this review, we analyzed the global experience of using machine perfusion in livertransplantation through the history ofthe development ofthis method to the latest trends and possibilities for increasing the number of liver transplants.

Normothermic ex vivo kidney perfusion preserves mitochondrial and graft function after warm ischemia and is further enhanced by AP39.

We previously reported that normothermic ex vivo kidney  perfusion (NEVKP) is superior in terms of organ protection compared to static cold storage (SCS), which is still the standard method of organ preservation, but the mechanisms are incompletely understood. We used a large animal kidney autotransplant model to evaluate mitochondrial function during organ preservation and after kidney transplantation, utilizing live cells extracted from fresh kidney tissue. Male porcine kidneys stored under normothermic perfusion showed preserved mitochondrial function and higher ATP levels compared to kidneys stored at 4 °C (SCS). Mitochondrial respiration and ATP levels were further enhanced when AP39, a mitochondria-targeted hydrogen sulfide donor, was administered during warm perfusion. Correspondingly, the combination of NEVKP and AP39 was associated with decreased oxidative stress and inflammation, and with improved graft function after transplantation. In conclusion, our findings suggest that the organ-protective effects of normothermic perfusion are mediated by maintenance of mitochondrial function and enhanced by AP39 administration. Activation of mitochondrial function through the combination of AP39 and normothermic perfusion could represent a new therapeutic strategy for long-term renal preservation.

Perfusate Exchange Does Not Improve Outcomes in 24-hour Ex Situ Lung Perfusion.

BACKGROUND: Reliable 24-hour preservation is required to optimize the rehabilitation potential of Ex Situ Lung Perfusion (ESLP). Other ESLP protocols include fresh perfusate replacement to counteract an accumulation of deleterious by-products. We describe the results of our reliable 24-hour negative pressure ventilation (NPV)-ESLP protocol with satisfactory acute post-transplant outcomes and investigate perfusate exchange (PE) as a modification to enhance prolonged ESLP. METHODS: Twelve pig lungs underwent 24 hours of NPV-ESLP using 1.5L of cellular perfusate (500 mL packed red blood cells and 1 L buffered perfusate). The Control (n = 6) had no PE; the PE (n = 6) had 500 mL replaced after 12 hours of NPV-ESLP with 1000 mL fresh perfusate. Three left lungs per group were transplanted. RESULTS: Results are reported as Control vs PE (mean ± SEM). Both groups demonstrated stable and acceptable oxygenation during 24 hours of ESLP with final PF ratios of 527.5 ± 42.19 and 488.4 ± 35.38 (P = .25). Final compliance measurements were 20.52 ± 3.59 and 18.55 ± 2.91 (P = .34). There were no significant differences in pulmonary artery pressure after 24 hours of ESLP (10.02 ± 2.69 vs 14.34 ± 1.64, P = .10), and pulmonary vascular resistance only differed significantly at T12 (417.6 ± 53.06 vs 685.4 ± 81.19, P = .02). Percentage weight gain between groups was similar (24.32 ± 8.4 and 45.33 ± 7.76, P = .07). Post-transplant left lung oxygenation was excellent (327.3 ± 14.62 and 313.3 ± 15.38, P = .28). There was no significant difference in % weight gain of lungs post-transplant (22.20 ± 7.22 vs 14.36 ± 9.96, P = .28). CONCLUSION: Acceptable lung function was maintained during 24-hour NPV-ESLP and post-transplant regardless of PE.

Moderate-Flow Perfusion is Superior to Low-Flow Perfusion in Ex Situ Lung Perfusion.

BACKGROUND: Full-flow perfusion during prolonged ex situ lung perfusion (ESLP) results in unacceptable pulmonary edema formation. Clinical ESLP at 30% to 50% predicted cardiac output (CO) supports acceptable physiologic outcomes; however, progressive pulmonary edema still develops. Lower flow rates may provide equivalent physiologic preservation with less edema formation due to reduced hydrostatic pressures. We report our results of moderate-flow (MF; 30% CO) vs low-flow (LF; 10% CO) negative pressure ventilation (NPV)-ESLP with transplantation. METHODS: Twelve pig lungs underwent 12-hours of NPV-ESLP with 30% or 10% CO (n = 6/group). Three left lungs per group were transplanted post-ESLP and assessed in vivo over 4 hours. Lung function was assessed by physiologic parameters, weight-gain, and pro-inflammatory cytokine profiles. RESULTS: Results are MF vs LF (mean ± SEM). All lungs demonstrated acceptable oxygenation post-ESLP (454.2 ± 40.85 vs 422.7 ± 31.68, P = .28); however, after transplantation, the MF lungs demonstrated significantly better oxygenation (300.7 ± 52.26 vs 141.9 ± 36.75, P = .03). There was no significant difference in compliance after ESLP (21.38 ± 2.28 vs 16.48 ± 2.34, P = .08); however, pulmonary artery pressure (PAP; 10.89 ± 2.28 vs 21.11 ± 0.93, P = .06) and pulmonary vascular resistance (PVR; 438.60 ± 97.97 vs 782.20 ± 162.20, P = .05) were significantly higher in the LF group. Weight gain (%) post-ESLP and post-transplant was similar between groups (29.42 ± 5.72 vs 24.17 ± 4.42, P = .24; and 29.63 ± 7.23 vs 57.04 ± 15.78, P = .09). TNF-α and IL-6 were significantly greater throughout LF ESLP. CONCLUSIONS: The MF NPV-ESLP results in superior lung function with less inflammation compared to LF NPV-ESLP.

Ischemia-Free Liver Transplant: Technical Aspects and Considerations After First Case in Western Countries.

The use of marginal donor livers, particularly steatotic livers, could help to resolve the problem of organ shortage and wait list mortality. Ischemia-free liver transplant with the potential to avoid ischemiareperfusion injury and related complications, particularly early allograft dysfunction, could positively encourage the use of marginal donorlivers and extend the donor pool. Here, we describe the first case in a Western country of ischemia-free liver transplant of a marginal donor liver. To date, a research team in China is the only group to have described and used this technique. The technical and setup aspects are illustrated, and present controversies are discussed. A 58-year-old female patient received a transplant of a >60% steatotic donor liver. The transplant was accomplished with the ischemia-free liver transplant technique, and the donor liver was procured and transplanted under continuous normothermic machine perfusion. The donor liver functional parameters under normothermic machine perfusion were reassuring, and recipient recovery was uneventful. Although ischemia-free liver transplant is a technically and organizationally demanding procedure, our case demonstrates the feasibility of the ischemia-free liver transplant technique and encourages the development and expansion of its use.