Viability assessment of the liver during ex-situ machine perfusion prior to transplantation.

PURPOSE OF REVIEW: In an attempt to reduce waiting list mortality in liver transplantation, less-than-ideal quality donor livers from extended criteria donors are increasingly accepted. Predicting the outcome of these organs remains a challenge. Machine perfusion provides the unique possibility to assess donor liver viability pretransplantation and predict postreperfusion organ function. RECENT FINDINGS: Assessing liver viability during hypothermic machine perfusion remains challenging, as the liver is not metabolically active. Nevertheless, the levels of flavin mononucleotide, transaminases, lactate dehydrogenase, glucose and pH in the perfusate have proven to be predictors of liver viability. During normothermic machine perfusion, the liver is metabolically active and in addition to the perfusate levels of pH, transaminases, glucose and lactate, the production of bile is a crucial criterion for hepatocyte viability. Cholangiocyte viability can be determined by analyzing bile composition. The differences between perfusate and bile levels of pH, bicarbonate and glucose are good predictors of freedom from ischemic cholangiopathy. SUMMARY: Although consensus is lacking regarding precise cut-off values during machine perfusion, there is general consensus on the importance of evaluating both hepatocyte and cholangiocyte compartments. The challenge is to reach consensus for increased organ utilization, while at the same time pushing the boundaries by expanding the possibilities for viability testing.

Graft repair during machine perfusion: a current overview of strategies.

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.

Successful adult domino living donor liver transplantation in methylmalonic acidemia: case report.

Background: Liver transplantation (LT) is a therapeutic option in multiple inherited metabolic diseases (IMDs), including methylmalonic acidemia (MMA), as LT reduces the risk of acute metabolic decompensations and long-term complications associated with these diseases. In certain IMDs, such as maple syrup urine disease (MSUD), domino liver transplant (DLT) is an accepted and safe method which expands the donor pool. However, only one adult case of DLT using an MMA donor liver has been reported; outcome and safety are still unknown and questioned. Case Description: In this case report, we describe our experience with DLT using MMA livers. Two adult MMA patients underwent living donor liver transplant (LDLT); their MMA livers were consecutively transplanted into two patients on the liver transplant waiting list who had limited chance of receiving a liver transplant in the short term due to their low model for end-stage liver disease (MELD) scores. No severe peri- or postoperative complications occurred, however the recipients of the MMA livers biochemically now have mild MMA. Conclusions: DLT using MMA grafts is a feasible strategy to treat end-stage liver disease and expand the donor organ pool. However, the recipient of the MMA domino liver may develop mild MMA which could affect quality of life, and long-term safety remains unclear. Further long-term of outcomes for domino recipients of MMA livers, focusing on quality of life and any metabolic complications of transplantation are needed to better define the risks and benefits.

Endothelial Cell Replacement of Human Veins, Modeling Vascular Repair and Endothelial Cell Chimerism.

Allogeneic transplant organs are potentially highly immunogenic. The endothelial cells (ECs) located within the vascular system serve as the primary interface between the recipient's immune system and the donor organ, playing a key role in the alloimmune response. In this study, we investigated the potential use of recipient-derived ECs in a vein recellularization model. In this study, human iliac veins underwent complete decellularization using a Triton X-100 protocol. We demonstrated the feasibility of re-endothelializing acellular blood vessels using either human umbilical cord vein endothelial cell or human venous-derived ECs, with this re- endothelialization being sustainable for up to 28 days in vitro. The re-endothelialized veins exhibited the restoration of vascular barrier function, along with the restoration of innate immunoregulatory capabilities, evident through the facilitation of monocytic cell transmigration and their polarization toward a macrophage phenotype following transendothelial extravasation. Finally, we explored whether recellularization with EC of a different donor could prevent antibody-mediated rejection. We demonstrated that in chimeric vessels, allogeneic EC became a target of the humoral anti-donor response after activation of the classical immune complement pathway whereas autologous EC were spared, emphasizing their potential utility before transplantation. In conclusion, our study demonstrates that replacement of EC in transplants could reduce the immunological challenges associated with allogeneic grafts.

Impact of EUS in liver transplantation workup for patients with unresectable perihilar cholangiocarcinoma.

BACKGROUND AND AIMS: For a highly selected group of patients with unresectable perihilar cholangiocarcinoma (pCCA), liver transplantation (LT) is a treatment option. The Dutch screening protocol comprises nonregional lymph node (LN) assessment by EUS, and whenever LN metastases are identified, further LT screening is precluded. The aim of this study is to investigate the yield of EUS in patients with pCCA who are potentially eligible for LT. METHODS: In this retrospective, nationwide cohort study, all consecutive patients with suspected unresectable pCCA who underwent EUS in the screening protocol for LT were included from 2011 to 2021. During EUS, sampling of a "suspicious" nonregional LN was performed based on the endoscopist's discretion. The primary outcome was the added value of EUS, defined as the number of patients who were precluded from further screening because of malignant LNs. RESULTS: A total of 75 patients were included in whom 84 EUS procedures were performed, with EUS-guided tissue acquisition confirming malignancy in LNs in 3 of 75 (4%) patients. In the 43 who underwent surgical staging according to the protocol, nonregional LNs with malignancy were identified in 6 (14%) patients. Positive regional LNs were found in 7 patients in post-LT-resected specimens. CONCLUSIONS: Our current EUS screening for the detection of malignant LNs in patients with pCCA eligible for LT shows a limited but clinically important yield. EUS with systematic screening of all LN stations, both regional and nonregional, and the sampling of suspicious lymph nodes according to defined and set criteria could potentially increase this yield.

Prevention of infections and fever to improve outcome in older patients with acute stroke (PRECIOUS): a randomised, open, phase III, multifactorial, clinical trial with blinded outcome assessment.

Background: Infections and fever after stroke are associated with poor functional outcome or death. We assessed whether prophylactic treatment with anti-emetic, antibiotic, or antipyretic medication would improve functional outcome in older patients with acute stroke. Methods: We conducted an international, 2∗2∗2-factorial, randomised, controlled, open-label trial with blinded outcome assessment in patients aged 66 years or older with acute ischaemic stroke or intracerebral haemorrhage and a score on the National Institutes of Health Stroke Scale ≥ 6. Patients were randomly allocated (1:1) to metoclopramide (oral, rectal, or intravenous; 10 mg thrice daily) vs. no metoclopramide, ceftriaxone (intravenous; 2000 mg once daily) vs. no ceftriaxone, and paracetamol (oral, rectal, or intravenous; 1000 mg four times daily) vs. no paracetamol, started within 24 h after symptom onset and continued for four days. All participants received standard of care. The target sample size was 3800 patients. The primary outcome was the score on the modified Rankin Scale (mRS) at 90 days analysed with ordinal logistic regression and reported as an adjusted common odds ratio (an acOR < 1 suggests benefit and an acOR > 1 harm). This trial is registered (ISRCTN82217627). Findings: From April 2016 through June 2022, 1493 patients from 67 European sites were randomised to metoclopramide (n = 704) or no metoclopramide (n = 709), ceftriaxone (n = 594) or no ceftriaxone (n = 482), and paracetamol (n = 706) or no paracetamol (n = 739), of whom 1471 were included in the intention-to-treat analysis. Prophylactic use of study medication did not significantly alter the primary outcome at 90 days: metoclopramide vs. no metoclopramide (adjusted common odds ratio [acOR], 1.01; 95% CI 0.81-1.25), ceftriaxone vs. no ceftriaxone (acOR 0.99; 95% CI 0.77-1.27), paracetamol vs. no paracetamol (acOR 1.19; 95% CI 0.96-1.47). The study drugs were safe and not associated with an increased incidence of serious adverse events. Interpretation: We observed no sign of benefit of prophylactic use of metoclopramide, ceftriaxone, or paracetamol during four days in older patients with a moderately severe to severe acute stroke. Funding: This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No: 634809.

The Yield of Routine Post-Operative Doppler Ultrasound to Detect Early Post-Liver Transplantation Vascular Complications.

Early detection of liver transplantation (LT) vascular complications enables timely management. Our aim was to assess if routine Doppler ultrasound (rDUS) improves the detection of hepatic artery thrombosis (HAT), portal vein thrombosis (PVT) and hepatic venous outflow obstruction (HVOO). We retrospectively analysed timing and outcomes, number needed to diagnose one complication (NND) and positive predictive value (PPV) of rDUS on post-operative day (POD) 0,1 and 7 in 708 adult patients who underwent primary LT between 2010-2022. We showed that HAT developed in 7.1%, PVT in 8.2% and HVOO in 3.1% of patients. Most early complications were diagnosed on POD 0 (26.9%), 1 (17.3%) and 5 (17.3%). rDUS correctly detected 21 out of 26 vascular events during the protocol days. PPV of rDUS was 53.8%, detection rate 1.1% and NND was 90.5. Median time to diagnosis was 4 days for HAT and 47 days for PVT and 21 days for HVOO. After intervention, liver grafts were preserved in 57.1%. In conclusion, rDUS protocol helps to detect first week's vascular events, but with low PPV and a high number of ultrasounds needed.

Endoscopic ultrasound in patients with resectable perihilar cholangiocarcinoma: impact on clinical decision-making.

Background and study aims Accurate assessment of the lymph node (LN) status is crucial in resectable perihilar cholangiocarcinoma (pCCA) to prevent major surgery in patients with extraregional metastatic LNs (MLNs). This study investigates the added value of preoperative endoscopic ultrasound (EUS) with or without tissue acquisition (TA) for the detection of MLNs in patients with resectable pCCA. Patients and methods In this retrospective, multicenter cohort study, patients with potentially resectable pCCA who underwent EUS preoperatively between 2010-2020, were included. The clinical impact of EUS-TA was defined as the percentage of patients who did not undergo surgical resection due to MLNs found with EUS-TA. Findings of cross-sectional imaging were compared with EUS-TA findings and surgery. Results EUS was performed on 141 patients, of whom 107 (76 %) had suspicious LNs on cross-sectional imaging. Surgical exploration was prevented in 20 patients (14 %) because EUS-TA detected MLNs, of which 17 (85 %) were extraregional. Finally, 74 patients (52 %) underwent surgical exploration followed by complete resection in 40 (28 %). MLNs were identified at definitive pathology in 24 (33 %) patients, of which 9 (38 %) were extraregional and 15 (63 %) regional. Conclusions EUS-TA may be of value in patients with potentially resectable pCCA based on preoperative cross-sectional imaging, regardless of lymphadenopathy at cross-sectional imaging. A prospective study in which a comprehensive EUS investigation with LN assessment and EUS-TA of LNs is performed routinely should confirm this promise.

Utilization of livers donated after circulatory death for transplantation - An international comparison.

BACKGROUND & AIMS: Liver graft utilization rates are a hot topic due to the worldwide organ shortage and the increasing number of transplant candidates on waiting lists. Liver perfusion techniques have been introduced in several countries, and may help to increase the organ supply, as they potentially enable the assessment of livers before use. METHODS: Liver offers were counted from donation after circulatory death (DCD) donors (Maastricht type III) arising during the past decade in eight countries, including Belgium, France, Italy, the Netherlands, Spain, Switzerland, the UK, and the US. Initial type-III DCD liver offers were correlated with accepted, recovered and implanted livers. RESULTS: A total number of 34,269 DCD livers were offered, resulting in 9,780 liver transplants (28.5%). The discard rates were highest in the UK and US, ranging between 70 and 80%. In contrast, much lower DCD liver discard rates, e.g. between 30-40%, were found in Belgium, France, Italy, Spain and Switzerland. In addition, we observed large differences in the use of various machine perfusion techniques, as well as in graft and donor risk factors. For example, the median donor age and functional donor warm ischemia time were highest in Italy, e.g. >40 min, followed by Switzerland, France, and the Netherlands. Importantly, such varying risk profiles of accepted DCD livers between countries did not translate into large differences in 5-year graft survival rates, which ranged between 60-82% in this analysis. CONCLUSIONS: Overall, DCD liver discard rates across the eight countries were high, although this primarily reflects the situation in the Netherlands, the UK and the US. Countries where in situ and ex situ machine perfusion strategies were used routinely had better DCD utilization rates without compromised outcomes. IMPACT AND IMPLICATIONS: A significant number of Maastricht type III DCD livers are discarded across Europe and North America today. The overall utilization rate among eight Western countries is 28.5% but varies significantly between 18.9% and 74.2%. For example, the median DCD-III liver utilization in five countries, e.g. Belgium, France, Italy, Switzerland, and Spain is 65%, in contrast to 24% in the Netherlands, UK and US. Despite this, and despite different rules and strategies for organ acceptance and preservation, 1- and 5-year graft survival rates remain fairly similar among all participating countries. A highly varying experience with modern machine perfusion technology was observed. In situ and ex situ liver perfusion concepts, and application of assessment tools for type-III DCD livers before transplantation, may be a key explanation for the observed differences in DCD-III utilization.

Modeling bile duct ischemia and reoxygenation injury in human cholangiocyte organoids for screening of novel cholangio-protective agents.

BACKGROUND: Ischemia of the bile duct is a common feature in liver disease and transplantation, which represents a major cause of morbidity and mortality, especially after liver transplantation. Detailed knowledge of its pathogenesis remains incomplete due to the lack of appropriate in vitro models. METHODS: To recapitulate biliary damage induced by ischemia and reperfusion in vitro, human intrahepatic cholangiocyte organoids (ICOs) were grown at low oxygen levels of 1% up to 72 h, followed by re-oxygenation at normal levels. FINDINGS: ICOs stressed by ischemia and subsequent re-oxygenation represented the dynamic change in biliary cell proliferation, upregulation of epithelial-mesenchymal transition (EMT)-associated markers, and the evocation of phase-dependent cell death programs similar to what is described in patients. Clinical-grade alpha-1 antitrypsin was identified as a potent inhibitor of both ischemia-induced apoptosis and necroptosis. INTERPRETATION: These findings demonstrate that ICOs recapitulate ischemic cholangiopathy in vitro and enable drug assessment studies for the discovery of new therapeutics for ischemic cholangiopathies. FUNDING: Dutch Digestive FoundationMLDS D16-26; TKI-LSH (Topconsortium Kennis en Innovatie-Life Sciences & Health) grant RELOAD, EMC-LSH19002; Medical Delta program "Regenerative Medicine 4D"; China Scholarship Council No. 201706230252.

Major complications and mortality after resection of intrahepatic cholangiocarcinoma: A systematic review and meta-analysis.

BACKGROUND: Evaluation of morbidity and mortality after hepatic resection often lacks stratification by extent of resection or diagnosis. Although a liver resection for different indications may have technical similarities, postoperative outcomes differ. The aim of this systematic review and meta-analysis was to determine the risk of major complications and mortality after resection of intrahepatic cholangiocarcinoma. METHODS: Meta-analysis was performed to assess postoperative mortality (in-hospital, 30-, and 90-day) and major complications (Clavien-Dindo grade ≥III). RESULTS: A total of 32 studies that reported on 19,503 patients were included. Pooled in-hospital, 30-day, and 90-day mortality were 5.9% (95% confidence interval 4.1-8.4); 4.6% (95% confidence interval 4.0-5.2); and 6.1% (95% confidence interval 5.0-7.3), respectively. Pooled proportion of major complications was 22.2% (95% confidence interval 17.7-27.5) for all resections. The pooled 90-day mortality was 3.1% (95% confidence interval 1.8-5.2) for a minor resection, 7.4% (95% confidence interval 5.9-9.3) for all major resections, and 11.4% (95% confidence interval 6.9-18.7) for extended resections (P = .001). Major complications were 38.8% (95% confidence interval 29.5-49) after a major hepatectomy compared to 11.3% (95% confidence interval 5.0-24.0) after a minor hepatectomy (P = .001). Asian studies had a pooled 90-day mortality of 4.4% (95% confidence interval 3.3-5.9) compared to 6.8% (95% confidence interval 5.6-8.2) for Western studies (P = .02). Cohorts with patients included before 2000 had a pooled 90-day mortality of 5.9% (95% confidence interval 4.8-7.3) compared to 6.8% (95% confidence interval 5.1-9.1) after 2000 (P = .44). CONCLUSION: When informing patients or comparing outcomes across hospitals, postoperative mortality rates after liver resection should be reported for 90-days with consideration of the diagnosis and the extent of liver resection.

Scalable Production of Size-Controlled Cholangiocyte and Cholangiocarcinoma Organoids within Liver Extracellular Matrix-Containing Microcapsules.

Advances in biomaterials, particularly in combination with encapsulation strategies, have provided excellent opportunities to increase reproducibility and standardization for cell culture applications. Herein, hybrid microcapsules are produced in a flow-focusing microfluidic droplet generator combined with enzymatic outside-in crosslinking of dextran-tyramine, enriched with human liver extracellular matrix (ECM). The microcapsules provide a physiologically relevant microenvironment for the culture of intrahepatic cholangiocyte organoids (ICO) and patient-derived cholangiocarcinoma organoids (CCAO). Micro-encapsulation allowed for the scalable and size-standardized production of organoids with sustained proliferation for at least 21 days in vitro. Healthy ICO (n = 5) expressed cholangiocyte markers, including KRT7 and KRT19, similar to standard basement membrane extract cultures. The CCAO microcapsules (n = 3) showed retention of stem cell phenotype and expressed LGR5 and PROM1. Furthermore, ITGB1 was upregulated, indicative of increased cell adhesion to ECM in microcapsules. Encapsulated CCAO were amendable to drug screening assays, showing a dose-response response to the clinically relevant anti-cancer drugs gemcitabine and cisplatin. High-throughput drug testing identified both pan-effective drugs as well as patient-specific resistance patterns. The results described herein show the feasibility of this one-step encapsulation approach to create size-standardized organoids for scalable production. The liver extracellular matrix-containing microcapsules can provide a powerful platform to build mini healthy and tumor tissues for potential future transplantation or personalized medicine applications.

[Heart donation after circulatory death: ethical and emotional aspect of central normothermic regional perfusion]. / Hoe behoud je een donorhart na circulatoir overlijden?

Heart transplantation after circulatory death is possible in different countries with the use of ex situ normothermic perfusion of the donor heart. Central normothermic regional perfusion, where the circulation in the donor is restarted using an extracorporeal life support system after circulatory death, may give a better 1-years survival and a reduction in costs compared to ex situ normothermic perfusion of the donor heart. However, restarting circulation in a donor that was just declared death by circulatory criteria may be controversial. The advantages described are, in our view, reason to consider central normothermic regional perfusion, in which case a debate on ethical and emotional aspects is of great importance. In this article, we describe two point of views and hope in this way to start the debate on central normothermic regional perfusion in the Netherlands.

Success, complication, and mortality rates of initial biliary drainage in patients with unresectable perihilar cholangiocarcinoma.

BACKGROUND: The patients with unresectable perihilar cholangiocarcinoma require biliary drainage to relieve symptoms and allow for palliative systemic chemotherapy. The aim of this study was to establish the success, complication, and mortality rates of the initial biliary drainage in patients with unresectable perihilar cholangiocarcinoma at presentation. METHODS: In this retrospective multicenter study, patients with unresectable perihilar cholangiocarcinoma who underwent initial endoscopic or percutaneous transhepatic biliary drainage between 2002 and 2014 were included. The success of drainage was defined as a successful biliary stent or drain placement, no unscheduled reintervention within 14 days, and serum bilirubin levels <50 µmol/L (ie, 2.9 mg/dL) or a >50% decrease in serum bilirubin after 14 days. Severe complications, and 90-day mortality were recorded. RESULTS: Included were 186 patients: 161 (87%) underwent initial endoscopic biliary drainage and 25 (13%) underwent initial percutaneous transhepatic biliary drainage. The success of initial drainage was observed in 73 patients (45%) after endoscopic biliary drainage and 6 (24%) after percutaneous transhepatic biliary drainage. The reasons for an unsuccessful initial drainage were: the failure to place a drain or stent in 39 patients (21%), an unplanned reintervention within 14 days in 52 patients (28%), and the bilirubin level >50 µmol/L (or not halved) after 14 days of initial drainage in 16 patients (9%). Severe drainage-related complications occurred in 19 patients (12%) after endoscopic biliary drainage and in 3 (12%) after percutaneous transhepatic biliary drainage. Overall, 66 patients (36%) died within 90 days after initial biliary drainage. CONCLUSION: Initial biliary drainage in patients with unresectable perihilar cholangiocarcinoma had a success rate of 45% and a 90-day mortality rate of 36%. Future studies for patients with perihilar cholangiocarcinoma should focus on improving biliary drainage.

Salvage of Declined Extended-criteria DCD Livers Using In Situ Normothermic Regional Perfusion.

OBJECTIVE: This study investigates whether liver grafts donated after circulatory death (DCD) that are declined by the entire Eurotransplant region can be salvaged with abdominal normothermic regional perfusion (aNRP). BACKGROUND: aNRP is increasingly used for DCD liver grafts because it prevents typical complications. However, it is unclear whether aNRP is capable to rescue pretransplant declined liver grafts by providing the opportunity to test function during donation. METHODS: Donor livers from DCD donors, declined by all centers in the Eurotransplant region, were included for this study. The comparator cohort included standard DCD livers and livers donated after brain death, transplanted in the same time period. RESULTS: After the withdrawal of life-sustaining treatment, 28 from the 43 donors had a circulatory death within 2 hours, in which case aNRP was initiated. Of these 28 cases, in 3 cases perfusion problems occurred, 5 grafts were declined based on liver assessment, and 20 liver grafts were transplanted. The main differences during aNRP between the transplanted grafts and the assessed nontransplanted grafts were alanine transaminase levels of 53 U/L (34-68 U/L) versus 367 U/L (318-488 U/L) ( P =0.001) and bile production in 100% versus 50% of the grafts ( P =0.024). The 12-month graft and patient survival were both 95%, similar to the comparator cohort. The incidence of ischemic cholangiopathy was 11%, which was lower than in the standard DCD cohort (18%). CONCLUSION: aNRP can safely select and thus is able to rescue DCD liver grafts that were deemed unsuitable for transplantation, while preventing primary nonfunction and minimizing ischemic cholangiopathy.

The current status of stem cell-based therapies during ex vivo graft perfusion: An integrated review of four organs.

The use of extended criteria donor grafts is a promising strategy to increase the number of organ transplantations and reduce waitlist mortality. However, these organs are often compromised and/or damaged, are more susceptible to preservation injury, and are at risk for developing post-transplant complications. Ex vivo organ perfusion is a novel technology to preserve donor organs while providing oxygen and nutrients at distinct perfusion temperatures. This preservation method allows to resuscitate grafts and optimize function with therapeutic interventions prior to solid organ transplantation. Stem cell-based therapies are increasingly explored for their ability to promote regeneration and reduce the inflammatory response associated with in vivo reperfusion. The aim of this review is to describe the current state of stem cell-based therapies during ex vivo organ perfusion for the kidney, liver, lung, and heart. We discuss different strategies, including type of cells, route of administration, mechanisms of action, efficacy, and safety. The progress made within lung transplantation justifies the initiation of clinical trials, whereas more research is likely required for the kidney, liver, and heart to progress into clinical application. We emphasize the need for standardization of methodology to increase comparability between future (clinical) studies.

Liver Ischemia and Reperfusion Induce Periportal Expression of Necroptosis Executor pMLKL Which Is Associated With Early Allograft Dysfunction After Transplantation.

Background: Early allograft dysfunction (EAD) following liver transplantation (LT) remains a major threat to the survival of liver grafts and recipients. In animal models, it is shown that hepatic ischemia-reperfusion injury (IRI) triggers phosphorylation of Mixed Lineage Kinase domain-like protein (pMLKL) inducing necroptotic cell death. However, the clinical implication of pMLKL-mediated cell death in human hepatic IRI remains largely unexplored. In this study, we aimed to investigate the expression of pMLKL in human liver grafts and its association with EAD after LT. Methods: The expression of pMLKL was determined by immunohistochemistry in liver biopsies obtained from both human and rat LT. Human liver biopsies were obtained at the end of preservation (T0) and ~1 hour after reperfusion (T1). The positivity of pMLKL was quantified electronically and compared in rat and human livers and post-LT outcomes. Multiplex immunofluorescence staining was performed to characterize the pMLKL-expressing cells. Results: In the rat LT model, significant pMLKL expression was observed in livers after IRI as compared to livers of sham-operation animals. Similarly, the pMLKL score was highest after IRI in human liver grafts (in T1 biopsies). Both in rats and humans, the pMLKL expression is mostly observed in the portal triads. In grafts who developed EAD after LT (n=24), the pMLKL score at T1 was significantly higher as compared to non-EAD grafts (n=40). ROC curve revealed a high predictive value of pMLKL score at T1 (AUC 0.70) and the ratio of pMLKL score at T1 and T0 (pMLKL-index, AUC 0.82) for EAD. Liver grafts with a high pMLKL index (>1.64) had significantly higher levels of serum ALT, AST, and LDH 24 hours after LT compared to grafts with a low pMLKL index. Multivariate logistical regression analysis identified the pMLKL-index (Odds ratio=1.3, 95% CI 1.1-1.7) as a predictor of EAD development. Immunohistochemistry on serial sections and multiplex staining identified the periportal pMLKL-positive cells as portal fibroblasts, fibrocytes, and a minority of cholangiocytes. Conclusion: Periportal pMLKL expression increased significantly after IRI in both rat and human LT. The histological score of pMLKL is predictive of post-transplant EAD and is associated with early liver injury after LT. Periportal non-parenchymal cells (i.e. fibroblasts) appear most susceptible to pMLKL-mediated cell death during hepatic IRI.

Donor eligibility criteria and liver graft acceptance criteria during normothermic regional perfusion: A systematic review.

Acceptance of liver grafts from donations after circulatory death (DCD) largely remains a "black box," particularly due to the unpredictability of the agonal phase. Abdominal normothermic regional perfusion (aNRP) can reverse ischemic injury early during the procurement procedure, and it simultaneously enables graft viability testing to unravel this black box. This review evaluates current protocols for liver viability assessment to decide upon acceptance or decline during aNRP. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline was used, and relevant literature databases were searched. The primary outcome consisted of criteria for liver graft viability assessment. Secondary outcomes included survival, primary nonfunction (PNF), early dysfunction, and biliary complications. A total of 14 articles were included in the analysis. In all protocols, a combination of criteria was used to assess suitability of the liver for transplantation. As many as 12 studies (86%) used macroscopic assessment, 12 studies (86%) used alanine transaminase (ALT) levels in perfusate, 9 studies (64%) used microscopic assessment, and 7 studies (50%) used lactate levels as assessment criteria. The organ utilization rate (OUR) was 16% for uncontrolled donation after circulatory death (uDCD) and 64% for controlled donation after circulatory death (cDCD). The most used acceptation criterion in uDCD is ALT level (31%), while in cDCD macroscopic aspect (48%) is most used. Regarding postoperative complications, PNF occurred in 13% (6%-25%) of uDCD livers and 3% (2%-4%) of cDCD livers. In uDCD, the 1-year graft and patient survival rates were 75% (66%-82%) and 82% (75%-88%). In cDCD, the 1-year graft and patient survival rates were 91% (89%-93%) and 93% (91%-94%), respectively. In conclusion, the currently used assessment criteria consist of macroscopic aspect and transaminase levels. The acceptance criteria should be tailored according to donor type to prevent an unacceptable PNF rate in uDCD and to increase the relatively modest OUR in cDCD.

The role of T-tubes and abdominal drains on short-term outcomes in liver transplantation - A systematic review of the literature and expert panel recommendations.

BACKGROUND: This systematic review and expert panel recommendation aims to answer the question regarding the routine use of T-tubes or abdominal drains to better manage complications and thereby improve outcomes after liver transplantation. METHODS: Systematic review following PRISMA guidelines and recommendations using the GRADE approach derived from an international expert panel to assess the potential risks and benefits of T-tubes and intra-abdominal drainage in liver transplantation (CRD42021243036). RESULTS: Of the 2996 screened records, 33 studies were included in the systematic review, of which 29 (six RCTs) assessed the use of T-tubes and four regarding surgical drains. Although some studies reported less strictures when using a T-tube, there was a trend toward more biliary complications with T-tubes, mainly related to biliary leakage. Due to the small number of studies, there was a paucity of evidence on the effect of abdominal drains with no clear benefit for or against the use of drainage. However, one study investigating the open vs. closed circuit drains found a significantly higher incidence of intra-abdominal infections when open-circuit drains were used. CONCLUSIONS: Due to the potential risk of biliary leakage and infections, the routine intraoperative insertion of T-tubes is not recommended (Level of Evidence moderate - very low; grade of recommendation strong). However, a T-tube can be considered in cases at risk for biliary stenosis. Due to the scant evidence on abdominal drainage, no change in clinical practice in individual centers is recommended. (Level of Evidence very low; weak recommendation).