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The liver has been studied extensively due to the broad number of diseases affecting its vital functions. However, therapeutic advances have been hampered by the lack of knowledge concerning human hepatic development. Here, we addressed this limitation by describing the developmental trajectories of different cell types that make up the human liver at single-cell resolution. These transcriptomic analyses revealed that sequential cell-to-cell interactions direct functional maturation of hepatocytes, with non-parenchymal cells playing essential roles during organogenesis. We utilized this information to derive bipotential hepatoblast organoids and then exploited this model system to validate the importance of signalling pathways in hepatocyte and cholangiocyte specification. Further insights into hepatic maturation also enabled the identification of stage-specific transcription factors to improve the functionality of hepatocyte-like cells generated from human pluripotent stem cells. Thus, our study establishes a platform to investigate the basic mechanisms directing human liver development and to produce cell types for clinical applications.

Background Laparoscopic liver resections for malignancy are increasing worldwide, and yet data from North America are lacking. We aimed to assess the long-term outcomes of patients undergoing laparoscopic liver resection and open liver resection as a treatment for hepatocellular carcinoma. Methods Patients undergoing liver resection for hepatocellular carcinoma between January 2008 and December 2019 were retrospectively studied. A propensity score matching was performed using patient demographics, laboratory parameters, etiology of liver disease, liver function, and tumor characteristics. Primary outcomes included overall survival and cumulative incidence of recurrence. Kaplan-Meier and competing risk cumulative incidence were used for survival analyses. Multivariable Cox regression and Fine-Gray proportional hazard regression were performed to determine hazard for death and recurrence, respectively. Results Three hundred and ninety-one patients were identified (laparoscopic liver resection: 110; open liver resection: 281). After propensity score matching, 149 patients remained (laparoscopic liver resection: 57; open liver resection: 92). There were no significant differences between groups with regard to extent of hepatectomy performed and tumor characteristics. The laparoscopic liver resection group experienced a lower proportion of ≥Clavien-Dindo grade III complications (14% vs 29%; P = .01). In the matched cohort, the 1-, 3-, and 5-year overall survival rate in the laparoscopic liver resection versus open liver resection group was 90.9%, 79.3%, 70.5% vs 91.3%, 88.5%, 83.1% (P = .26), and the cumulative incidence of recurrence 31.1%, 59.7%, 62.9% vs 18.9%, 40.6%, 49.2% (P = .06), respectively. Conclusion This study represents the largest single institutional study from North America comparing long-term oncologic outcomes of laparoscopic liver resection and open liver resection as a treatment for primary hepatocellular carcinoma. The combination of reduced short-term complications and equivalent long-term oncologic outcomes favor the laparoscopic approach when feasible.

Living donor liver transplantation (LDLT) is an attractive alternative to deceased donor liver transplantation (DDLT). Although both modalities have similar short-term outcomes, long-term outcomes are not well studied. We compared the 20-year outcomes of 668 adults who received LDLT with1596 DDLTs at the largest liver transplantation (LT) program in Canada. Recipients of LDLT were significantly younger and more often male than DDLT recipients (P 0.001). Autoimmune diseases were more frequent in LDLT, whereas viral hepatitis and alcohol-related liver disease were more frequent in DDLT. LDLT recipients had lower Model for End-Stage Liver Disease scores (P = 0.008), spent less time on the waiting list (P 0.001), and were less often inpatients at the time of LT (P 0.001). In a nonadjusted analysis, 1-year, 10-year, and 20-year patient survival rates were significantly higher in LDLT (93%, 74%, and 56%, respectively) versus DDLT (91%, 67%, and 46%, respectively; log-rank P = 0.02) as were graft survival rates LDLT (91%, 67%, and 50%, respectively) versus (90%, 65%, and 44.3%, respectively, for DDLT; log-rank P = 0.31). After multivariable adjustment, LDLT and DDLT were associated with a similar hazard of patient and graft survival. Our data of 20 years of follow-up of LDLT from a single, large Western center demonstrates excellent long-term outcomes for recipients of LDLT.

BACKGROUND The main concern with live donor liver transplantation (LDLT) is the risk to the donor. Given the potential risk of liver insufficiency, most centers will only accept candidates with future liver remnants (FLR) >30%. We aimed to compare postoperative outcomes of donors who underwent LDLT with FLR ≤30% and >30%. METHODS Adults who underwent right hepatectomy for LDLT between 2000 and 2018 were analyzed. Remnant liver volumes were estimated using hepatic volumetry. To adjust for between-group differences, donors with FLR ≤30% and >30% were matched 1:2 based on baseline characteristics. Postoperative complications including liver dysfunction were compared between the groups. RESULTS A total of 604 live donors were identified, 28 (4.6%) of whom had a FLR ≤30%. Twenty-eight cases were successfully matched with 56 controls; the matched cohorts were mostly similar in terms of donor and graft characteristics. The calculated median FLR was 29.8 (range, 28.0-30.0) and 35.2 (range, 30.1-68.1) in each respective group. Median follow-up was 36.5 mo (interquartile range, 11.8-66.1). Postoperative outcomes were similar between groups. No difference was observed in overall complication rates (FLR ≤30%: 32.1% versus FLR >30%: 28.6%; odds ratio [OR], 1.22; 95% confidence interval [CI], 0.46-3.27) or major complication rates (FLR ≤30%: 14.3% versus FLR >30%: 14.3%; OR, 1.17; 95% CI, 0.33-4.10). Posthepatectomy liver failure was rare, and no difference was observed (FLR ≤30%: 3.6% versus FLR >30%: 3.6%; OR, 1.09; 95% CI, 0.11-11.1). CONCLUSION A calculated FLR between 28% and 30% on its own should not represent a formal contraindication for live donation.

Liver transplantation is currently the only treatment for end-stage liver disease and acute liver failure. Liver transplant rejection is among the most lethal complications of transplantation, and therapeutic development is limited by our lack of a comprehensive understanding of the cellular landscape of the liver. The laboratory rat (Rattus norvegicus), ideal in size as a model for surgical procedures, is a strong platform to study liver biology in the context of liver transplantation. Liver allograft rejection is known to be strain-specific in the rat model, although the transplantation is accepted without rejection in some strains, it leads to acute rejection in others. To shed light on the cellular landscape of the rat liver and build a foundation for strain comparison, we present a comprehensive single-cell transcriptomics map of the healthy rat liver of Lewis and Dark Agouti strains. Using a novel computational pipeline we developed to guide the detailed annotation of our rat liver atlas, we discovered that hepatic myeloid cells have strong Lewis and Dark Agouti strain-specific differences focused on inflammatory signaling pathways. We experimentally validated these strain-specific differences in myeloid inflammatory potentialin vitrousing intracellular cytokine staining. Our work provides the first examination of the multi-strain healthy rat liver by single cell transcriptomics and uncovers key insights into strain-specific differences in this valuable model animal.SummaryThe laboratory rat (Rattus norvegicus) is a standard model animal for orthotopic liver transplantation. Transplanting a liver from a Dark agouti (DA) to a Lewis (LEW) strain rat leads to transplant rejection and the reverse procedure leads to tolerance. Understanding this strain difference may help explain the cellular drivers of liver allograft rejection post-transplant. This study uses single-cell transcriptomics to better understand the complex cellular composition of the rat liver and unravels cellular and molecular sources of inter-strain hepatic variation. We generated single-cell transcriptomic maps of the livers of healthy DA and LEW rat strains and developed a novel, factor analysis-based bioinformatics pipeline to study data covariates, such as strain and batch. Using this approach, we discovered variations within hepatocyte and myeloid populations that explain how the states of these cells differ between strains in the healthy rat, which may explain why these strains respond differently to liver transplants.

The human liver is a complex organ made up of multiple specialized cell types that carry out key physiological functions. An incomplete understanding of liver biology limits our ability to develop therapeutics to prevent chronic liver diseases, liver cancers, and death as a result of organ failure. Recently, single-cell modalities have expanded our understanding of the cellular phenotypic heterogeneity and intercellular cross-talk in liver health and disease. This review summarizes these findings and looks forward to highlighting new avenues for the application of single-cell genomics to unravel unknown pathogenic pathways and disease mechanisms for the development of new therapeutics targeting liver pathology. As these technologies mature, their integration into clinical data analysis will aid in patient stratification and in developing treatment plans for patients suffering from liver disease.

Paired organ exchange can be used to circumvent living donor-recipient ABO incompatibilities. Herein, we present the first case of successful liver paired exchange in North America. This 2-way swap required 4 simultaneous operations: 2 living donor hepatectomies and 2 living donor liver transplants. A nondirected anonymous living donor gift initiated this domino exchange, alleviating an ABO incompatibility in the other donor-recipient pair. With careful attention to ethical and logistical issues, paired liver exchange is a feasible option to expand the donor pool for incompatible living liver donor-recipient pairs.

Recipients of donation after circulatory death (DCD) grafts are reportedly at higher risk of developing renal dysfunction after liver transplantation (LT). We compared the development of acute kidney injury (AKI) and chronic kidney disease (CKD) after LT in recipients of DCD versus donation after brain death (DBD) or living donor liver transplantation (LDLT) livers. Adult recipients of DBD, LDLT, and DCD between 2012 and 2016 at Toronto General Hospital were included. AKI was defined as a post‐LT increase of serum creatinine (sCr) ≥26.5 µmol/L within 48 hours or a ≥50% increase from baseline, and CKD was defined as an estimated glomerular filtration rate 3 months. A total of 681 patients (DCD, n = 57; DBD, n = 446; and LDLT, n = 178) with similar baseline comorbidities were included. Perioperative AKI (within the first 7 postoperative days) was observed more frequently in the DCD group (61%; DBD, 40%; and LDLT, 44%; P = 0.01) and was associated with significantly higher peak AST levels (P

The critical functions of the human liver are coordinated through the interactions of hepatic parenchymal and non-parenchymal cells. Recent advances in single-cell transcriptional approaches have enabled an examination of the human liver with unprecedented resolution. However, dissociation-related cell perturbation can limit the ability to fully capture the human liver's parenchymal cell fraction, which limits the ability to comprehensively profile this organ. Here, we report the transcriptional landscape of 73,295 cells from the human liver using matched single-cell RNA sequencing (scRNA-seq) and single-nucleus RNA sequencing (snRNA-seq). The addition of snRNA-seq enabled the characterization of interzonal hepatocytes at a single-cell resolution, revealed the presence of rare subtypes of liver mesenchymal cells, and facilitated the detection of cholangiocyte progenitors that had only been observed during in vitro differentiation experiments. However, T and B lymphocytes and natural killer cells were only distinguishable using scRNA-seq, highlighting the importance of applying both technologies to obtain a complete map of tissue-resident cell types. We validated the distinct spatial distribution of the hepatocyte, cholangiocyte, and mesenchymal cell populations by an independent spatial transcriptomics data set and immunohistochemistry. Conclusion: Our study provides a systematic comparison of the transcriptomes captured by scRNA-seq and snRNA-seq and delivers a high-resolution map of the parenchymal cell populations in the healthy human liver.

In western countries, the timing of liver retransplantation depends on recipient prioritization on the wait-list, as determined by their model for end-stage liver disease (MELD) score, and the availability of an appropriate deceased donor graft. Unfortunately, the MELD score in these patients often does not reflect their medical condition accurately, resulting in an increased risk of wait-list mortality1 . Living-donor liver transplantation (LDLT) offers the potential of timely retransplantation with a high quality graft.

Diabetes mellitus (DM) is said to adversely affect transplant outcomes. The aim of this study was to investigate the impact of pre-existing and new-onset DM on liver transplantation (LT) recipients.A single-center retrospective analysis of prospectively collected data of LT recipients (1990-2015) was undertaken.Of the 2209 patients, 13% (n = 298) had Pre-DM, 16% (n = 362) developed post-transplant diabetes mellitus (PTDM), 5% (n = 118) developed transient hyperglycemia (t-HG) post-LT, and 65% (n = 1431) never developed DM (no DM). Baseline clinical characteristics of patients with PTDM were similar to that of patients with Pre-DM. Incidence of PTDM peaked during the first year (87%) and plateaued thereafter. On multivariate analysis (Bonferroni-corrected), nonalcoholic fatty liver disease and the use of tacrolimus and sirolimus were independently associated with PTDM development. Both Pre-DM and PTDM patients had satisfactory and comparable glycemic control throughout the follow-up period. Those who developed t-HG seem to have a unique characteristic compared with others. Overall, 9%, 5%, and 8% of patients developed end-stage renal disease (ESRD), major cardiovascular event (mCVE), and de novo cancer, respectively. Both Pre-DM and PTDM did not adversely affect patient survival, retransplantation, or de novo cancer. The risks of ESRD and mCVE were significantly higher in patients with Pre-DM followed by PTDM and no DM.In this largest nonregistry study, patients with Pre-DM and PTDM share similar baseline clinical characteristics. Pre-DM increases the risk of ESRD and mCVE; however, patient survival was comparable to those with PTDM and without diabetes. Understanding the impact of PTDM would need prolonged follow-up.

Background and Aims. Ubiquitin-specific protease 18 (USP18) is involved in immunoregulation and response to interferon- (IFN-) based treatment in patients chronically infected with hepatitis C virus (HCV). We investigated whether and how its upregulation alters HCV infection. Methods. Overexpression of wild-type (USP18 WT) or catalytically inactive mutant (USP18 C64S) USP18 was examined for effects on HCV replication in the absence and presence of IFNα or IFNλ using both the HCV-infective model and replicon cells. The IFN signaling pathway was assessed via STAT1 phosphorylation (western blot) and downstream ISG expression (real-time PCR). Mechanistic roles were sought by quantifying microRNA-122 levels and J6/JFH1 infectivity of Huh7.5 cells. Results. We found that overexpression of either USP18 WT or USP18 C64S stimulated HCV production and blunted the anti-HCV effect of IFNα and IFNλ in the infective model but not in the replicon system. Overexpressed USP18 showed no effect on Jak/STAT signaling nor on microRNA-122 expression. However, USP18 upregulation markedly increased J6/JFH1 infectivity and promoted the expression of the key HCV entry factor CD81 on Huh7.5 cells. Conclusions. USP18 stimulates HCV production and blunts the effect of both type I and III IFNs by fostering a cellular environment characterized by upregulation of CD81, promoting virus entry and infectivity.

Background & Aims Death rates on liver transplant waiting lists range from 5%–25%. Herein, we report a unique experience with 50 anonymous individuals who volunteered to address this gap by offering to donate part of their liver to a recipient with whom they had no biological connection or prior relationship, so called anonymous live liver donation (A-LLD). Methods Candidates were screened to confirm excellent physical, mental, social, and financial health. Demographics and surgical outcomes were analyzed. Qualitative interviews after donation examined motivation and experiences. Validated self-reported questionnaires assessed personality traits and psychological impact. Results A total of 50 A-LLD liver transplants were performed between 2005 and 2017. Most donors had a university education, a middle-class income, and a history of prior altruism. Half were women. Median age was 38.5 years (range 20–59). Thirty-three (70%) learned about this opportunity through public or social media. Saving a life, helping others, generativity, and reciprocity for past generosity were motivators. Social, financial, healthcare, and legal support in Canada were identified as facilitators. A-LLD identified most with the personality traits of agreeableness and conscientiousness. The median hospital stay was 6 days. One donor experienced a Dindo-Clavien Grade 3 complication that completely resolved. One-year recipient survival was 91% in 22 adults and 97% in 28 children. No A-LLD reported regretting their decision. Conclusions This is the first and only report of the characteristics, motivations and facilitators of A-LLD in a large cohort. With rigorous protocols, outcomes are excellent. A-LLD has significant potential to reduce the gap between transplant organ demand and availability. Lay summary We report a unique experience with 50 living donors who volunteered to donate to a recipient with whom they had no biological connection or prior relationship (anonymous living donors). This report is the first to discuss motivations, strategies and facilitators that may mitigate physical, social and ethical risk factors in this patient population. With rigorous protocols, anonymous liver donation and recipient outcomes are excellent; with appropriate clinical expertise and system facilitators in place, our experience suggests that other centers may consider the procedure for its significant potential to reduce the gap between transplant organ demand and availability.

Background Portal vein embolization (PVE) is used before major hepatectomy for hepatocellular carcinoma (HCC) to increase future liver remnant (FLR) volume. However, this may increase tumour growth rate, leading to more extensive resections. This study aimed to determine the effect of tumour growth, following PVE, on treatment plan. Method Retrospective cohort study conducted on patients treated from 2008 to 2015 with PVE before major hepatectomy for HCC. Liver and tumour volumetry was performed on pre- and post-PVE CT scans. Image-based and actioned plans were compared before and after PVE. Results Thirty-one patients received PVE. Non-tumour total liver volume decreased (median 1440 to 1394 cm3; p = 0.031), while tumour (median 161–240 cm3; p Conclusion Following PVE in the setting of HCC, tumour progression accounts for a change in treatment plan in approximately a quarter of patients. Further research is warranted to determine whether additional liver directed therapy should routinely be used to slow the growth of HCC post-PVE.

Background Stage 3 pancreatic ductal adenocarcinoma (PDAC) is defined by arterial involvement. This study objective was to evaluate outcomes for patients with stage 3 PDAC with potentially reconstructable arterial involvement, considered for neoadjuvant therapy (NAT) and pancreatic resection, and to compare outcomes following arterial (AR) and non-arterial resection (NAR). Methods This study included patients from 2009 to 2016 with biopsy-proven stage 3 PDAC who were offered NAT before surgical exploration. AR was performed if required to achieve R0 resection. Time to event outcomes were analysed from diagnosis date. Results 87/89 patients (97.8%) received NAT (chemotherapy 41.6%, chemotherapy/radiotherapy 56.2%). 46/89 (51.7%) underwent exploration; 31 underwent resection (AR n = 20, NAR n = 11). AR patients had longer operative time (681 vs. 563 min, p = 0.006) and more blood loss (1600 vs. 575 mL, p = 0.0004), with no difference for blood transfusion, pancreatic fistula, length of stay, reoperation, or mortality. R0 rate was 30/31. Post-resection 90-day mortality was 3.2%. Median overall survival was statistically comparable between the AR and NAR groups (19.7 vs. 28.4 months, p = 0.41). Conclusions AR had comparable clinical and oncologic outcomes to NAR. Following careful selection and non-progression after NAT, major AR may cautiously be considered if required to obtain a negative resection margin.

Objective The aim of this study was to determine whether hepatic gene expression related to hepatocellular carcinoma (HCC) is associated with disease severity and modifiable lifestyle factors in non-alcoholic fatty liver disease (NAFLD). Methods In a cross-sectional study, the associations between hepatic gene expression and liver histology, insulin resistance, anthropometrics, diet, and physical activity were assessed in patients with non-alcoholic steatohepatitis (NASH; n = 19) or simple steatosis (SS; n = 20). In a group of patients with NASH, we then conducted a 1-y, single-arm, pilot study using ω-3 polyunsaturated fatty acid (PUFA) supplementation to determine whether changes in hepatic PUFA content would have a modulating effect on hepatic gene expression and would affect liver histology. Results In the cross-sectional study, histological features of disease severity correlated with AKR1B10, ANXA2, PEG10, SPP1, STMN2, MT1A, and MT1B in NASH and with EEF1A2, PEG10, and SPP1 in SS. In addition, PEG10, SPP1, ANXA2, and STMN2 expression correlated positively with insulin resistance in NASH. SPP1 and UBD correlated strongly with body mass index in SS. Associations between ENPP2, AKR1B10, SPP1, UBD, and waist circumference depended on sex and diagnosis. Several genes correlated with protein, fat, or carbohydrate intake. PEG10 correlated positively with physical activity in NASH and inversely with plasma vitamin C in both groups. Despite increased erythrocyte and hepatic ω-3 PUFA, supplementation did not alter hepatic gene expression and liver histology. Conclusions HCC-related gene expression was associated with liver histology, body mass index, waist circumference, diet, and physical activity but was not affected by ω-3 PUFA supplementation.

Radiofrequency ablation (RFA) is an effective treatment for single hepatocellular carcinoma (HCC) ≤3 cm. Disease recurrence is common, and in some patients will occur outside transplant criteria. We aimed to assess the incidence and risk factors for recurrence beyond Milan criteria in potentially transplantable patients treated with RFA as first-line therapy.We performed a retrospective cohort study of potentially transplantable patients with new diagnoses of unifocal HCC ≤3 cm that underwent RFA as first-line therapy between 2000-2015. We defined potentially transplantable patients as those aged70 years without any comorbidities that would preclude transplant surgery. Incidence of recurrence beyond Milan criteria was compared across 2 groups according to HCC diameter at the time of ablation: (HCC ≤2 cm vs. HCC2 cm). Competing risks Cox regression was used to identify predictors of recurrence beyond Milan criteria.We included 301 patients (167 HCC ≤2 cm and 134 HCC2 cm). Recurrence beyond Milan criteria occurred in 36 (21.6%) and 47 (35.1%) patients in the HCC ≤2 cm and the HCC2 cm groups, respectively (p = 0.01). The 1-, 3- and 5-year actuarial survival rates after RFA were 98.2%, 86.2% and 79.0% in the HCC ≤2 cm group vs. 93.3%, 77.6% and 70.9% in the HCC2 cm group (p = 0.01). Tumor size2 cm (hazard ratio 1.94; 95%CI 1.25-3.02) and alpha-fetoprotein levels at the time of ablation (100-1,000 ng/ml: hazard ratio 2.05; 95%CI 1.10-3.83) were found to be predictors of post-RFA recurrence outside Milan criteria.RFA for single HCC ≤3 cm provides excellent short- to medium-term survival. However, we identified patients at higher risk of recurrence beyond Milan criteria. For these patients, liver transplantation should be considered immediately after the first HCC recurrence following RFA.Radiofrequency ablation and liver transplantation are treatment options for early stages of hepatocellular carcinoma (HCC). After ablation some patients will experience recurrence or metastatic spread of the initial tumor or may develop new tumors within the liver. Despite close follow-up, these recurrences can progress rapidly and exceed transplant criteria, preventing the patient from receiving a transplant. We identified that patients with HCC2 cm and higher serum alpha-fetoprotein are at greater risk of recurrence beyond the transplant criteria. These data suggest that liver transplantation should be considered immediately after the first HCC recurrence for these patients.

Introduction and aim. Liver regeneration is a normal response to liver injury. The aim of this study was to determine the molecular basis of liver regeneration, through an integrative analysis of high-throughput gene expression datasets. Material and methods. We identified and curated datasets pertaining to liver regeneration from the Gene Expression Omnibus, where regenerating liver tissue was compared to healthy liver samples. The key dysregulated genes and pathways were identified using Ingenuity Pathway Analysis software. There were three eligible datasets in total. Results. In the early phase after hepatectomy, inflammatory pathways such as Nrf2 oxidative stress-mediated response and cytokine signaling were significantly upregulated. At peak regeneration, we discovered that cell cycle genes were predominantly expressed to promote cell proliferation. Using the Betweenness centrality algorithm, we discovered that Jun is the key central gene in liver regeneration. Calcineurin inhibitors may inhibit liver regeneration, based on predictive modeling. Conclusion. There is a paucity of human literature in defining the molecular mechanisms of liver regeneration along a time continuum. Nonetheless, using an integrative computational analysis approach to the available high-throughput data, we determine that the oxidative stress response and cytokine signaling are key early after hepatectomy, whereas cell cycle control is important at peak regeneration. The transcription factor Jun is central to liver regeneration and a potential therapeutic target. Future studies of regeneration in humans along a time continuum are needed to better define the underlying mechanisms, and ultimately enhance care of patients with acute and chronic liver failure while awaiting transplant.

Background /Objective. To determine the outcomes of a non-operative management approach for sporadic, small, non-functional pancreatic neuroendocrine tumours. Methods A retrospective chart review of patients with non-functional pancreatic neuroendocrine tumours initially managed non-operatively at a single institution was performed. Patients were identified through a search of radiologic reports, and individuals with ≥2 cross-sectional imaging studies performed >6 months apart from Jan. 1, 2000 to Dec. 31, 2013 were included. Data on tumour size, radiologic characteristics at diagnosis, interval radiologic growth, and surgical outcomes were recorded. Results Over the thirteen-year study period, 95 patients met inclusion criteria and were followed radiologically for a median of 36 months (18–69 months). Median initial tumour size on first imaging was 14.0 mm (IQR 10–19 mm). Median overall tumour growth rate was 0.03 mm/month (IQR: 0.00–0.14 mm/month). There was no significant relationship between initial tumour size and growth rate for tumours ≤ 2 cm or for lesions between 2 and 4 cm. Thirteen (14%) patients initially managed non-operatively underwent resection during the follow-up period. Reasons for surgery included interval tumour growth, patient anxiety or preference, or diagnostic uncertainty. Median time to surgery was 14 months (IQR 8–19 months). No patients progressed beyond resectability or developed metastatic disease during the observation period. Conclusion For patients with sporadic, small, non-functional pancreatic neuroendocrine tumours, radiologic surveillance appears to be a safe initial approach to management.

Background The left renal vein (LRV) may be used for venous reconstruction during hepato-pancreato-biliary (HPB) surgery, although concerns exist about compromising renal function. This study aimed to determine renal outcomes following LRV harvest during HPB resections. Methods Circumferential PV/SMV resections from 2008 to 2014 were included within two groups (LRV harvest, Control). Absolute and change in Creatinine (Cr) and estimated GFR (eGFR), and rates of acute kidney injury (AKI) and chronic kidney disease (CKD), were compared. Multivariate logistic regression analyses were performed. Results 76 patients were included (LRV n = 17, Control n = 59). Median Cr and eGFR did not change within groups, although change in eGFR differed between groups at postoperative day (POD) 3 (−4.3 vs. 12.8, p = 0.0035) and 7 (−1.8 vs. 12.4, p = 0.0074). AKI occurred more frequently in the LRV group at POD1 (5/17 vs. 4/59, p = 0.023) and POD3 (5/17 vs. 3/59, p = 0012), with no difference in CKD between groups (2/11 vs. 5/33 at 3 months, p = 0.99). LRV harvest was an independent risk factor for AKI at POD1 and POD3, but not thereafter. Conclusions Patients who undergo LRV harvest experience a higher rate of AKI in the first three post-operative days. LRV harvest during pancreas resection does not impact on long-term renal function.

Background Primary sclerosing cholangitis (PSC) is an indication for liver transplantation, but recurrence after liver transplantation is associated with poor outcomes often requiring repeat transplantation. We investigated whether autologous hematopoietic stem cell transplantation (aHSCT) could be used to stop progression of recurrent PSC and promote operational tolerance. Methods Twelve patients with recurrent PSC were fully evaluated and 5 were selected for aHSCT. Autologous hematopoietic stem cells were collected, purified by CD34 immunomagnetic selection and cryopreserved. Immunoablation using busulfan, cyclophosphamide and rabbit anti-thymocyte globulin was followed by aHSCT. The primary endpoint of the study was the establishment of operational tolerance defined as lack of biochemical, histologic and clinical evidence of rejection while off immunosuppression at 2 years post-aHSCT. Results Two of the 5 patients achieved operational tolerance with no clinical or histological evidence of PSC progression or allo-rejection. A third patient developed sinusoidal obstruction syndrome following aHSCT requiring repeat liver transplantation but has no evidence of PSC recurrence while on sirolimus monotherapy now more than 3 years after aHSCT. A fourth patient was weaned off immunosuppression but died 212 days after aHSCT from pericardial constriction. A fifth patient died from multiorgan failure. Immunosuppression-free allograft acceptance was associated with deletion of T cell clones, loss of autoantibodies and increases in regulatory T cells, transitional B cells, and programmed cell death protein-1 expressing CD8+ T cells in the 2 long-term survivors. Conclusions Although operational tolerance occurred following aHSCT, the high morbidity and mortality observed renders this specific protocol unsuitable for clinical adoption.

The critical functions of the human liver are coordinated through the interactions of hepatic parenchymal and non-parenchymal cells. Recent advances in single cell transcriptional approaches have enabled an examination of the human liver with unprecedented resolution. However, dissociation related cell perturbation can limit the ability to fully capture the human liver’s parenchymal cell fraction, which limits the ability to comprehensively profile this organ. Here, we report the transcriptional landscape of 73,295 cells from the human liver using matched single-cell RNA sequencing (scRNA-seq) and single-nucleus RNA sequencing (snRNA-seq). The addition of snRNA-seq enabled the characterization of interzonal hepatocytes at single-cell resolution, revealed the presence of rare subtypes of hepatic stellate cells previously only seen in disease, and detection of cholangiocyte progenitors that had only been observed during in vitro differentiation experiments. However, T and B lymphocytes and NK cells were only distinguishable using scRNA-seq, highlighting the importance of applying both technologies to obtain a complete map of tissue-resident cell-types. We validated the distinct spatial distribution of the hepatocyte, cholangiocyte and stellate cell populations by an independent spatial transcriptomics dataset and immunohistochemistry. Our study provides a systematic comparison of the transcriptomes captured by scRNA-seq and snRNA-seq and delivers a high-resolution map of the parenchymal cell populations in the healthy human liver.

Background. Early allograft dysfunction (EAD) after liver transplantation has been associated with long-term reduced graft and patient survival. Methods. In this single-center cohort study, we aimed to compare incidence, risk factors, and outcomes in liver transplant recipients who developed EAD. Patients who received donation after circulatory death (DOD) or donation after brain death (DBD) grafts between January 2007 and December 2017 were included. EAD was defined as bilirubin of 10mg/dL (171 mu mol/L) or an international normalized ratio of >= 1.6 on postoperative day 7 or transaminases >2000 U\L in the first-week post-transplantation as previously described. Results. In our cohort of 1068 patients, incidence of EAD was 44%. EAD occurred more frequently in the DOD versus DBD group (71% versus 41%, P

The rat orthotopic liver transplantation (OLT) model is a powerful tool to study acute and chronic rejection. However, it is not a complete representation of human liver transplantation due to the absence of arterial reconnection. Described here is a modified transplantation procedure that includes the incorporation of hepatic artery (HA) reconnection, leading to a marked improvement in transplant outcomes. With a mean anhepatic time of 12 min and 14 s, HA reconnection results in improved perfusion of the transplanted liver and an increase in long-term recipient survival from 37.5% to 88.2%. This protocol includes the use of 3D-printed cuffs and holders to connect the portal vein and infrahepatic inferior vena cava. It can be implemented for studying multiple aspects of liver transplantation, from immune response and infection to technical aspects of the procedure. By incorporating a simple and practical method for arterial reconnection using a microvascular technique, this modified rat OLT protocol closely mimics aspects of human liver transplantation and will serve as a valuable and clinically relevant research model.

There is a tremendous focus on the application of nanomaterials for the treatment of cancer. Nonprimate models are conventionally used to assess the biomedical utility of nanomaterials. However, these animals often lack an intact immunological background, and the tumors in these animals do not develop spontaneously. We introduce a preclinical woodchuck hepatitis virus-induced liver cancer model as a platform for nanoparticle (NP)-based in vivo experiments. Liver cancer development in these out-bred animals occurs as a result of persistent viral infection, mimicking human hepatitis B virus-induced HCC development. We highlight how this model addresses key gaps associated with other commonly used tumor models. We employed this model to (1) track organ biodistribution of gold NPs after intravenous administration, (2) examine their subcellular localization in the liver, (3) determine clearance kinetics, and (4) characterize the identity of hepatic macrophages that take up NPs using RNA-sequencing (RNA-seq). We found that the liver and spleen were the primary sites of NP accumulation. Subcellular analyses revealed accumulation of NPs in the lysosomes of CD14+ cells. Through RNA-seq, we uncovered that immunosuppressive macrophages within the woodchuck liver are the major cell type that take up injected NPs. The woodchuck-HCC model has the potential to be an invaluable tool to examine NP-based immune modifiers that promote host anti-tumor immunity.

The outcome after living donor liver transplantation (LDLT) using grafts with multiple bile ducts (BDs) remains unclear. We analyzed 510 patients who received an adult-to-adult right lobe LDLT between 2000 and 2015 and compared outcome parameters of those receiving grafts with 2 BDs (n = 169) with patients receiving grafts with 1 BD (n = 320). Additionally, patients receiving a graft with 3 BDs (n = 21) were analyzed. Demographic variables and disease severity were similar between the groups. Roux-en-Y reconstruction was significantly more common in the 2 BD group (77% versus 38%; P < 0.001) compared with the 1 BD group. No difference was found in biliary complication rates within 1 year after LDLT (1 BD versus 2 BD groups, 18% versus 21%, respectively; P = 0.46). In the 2 BD group, 82/169 (48.5%) patients were reconstructed with 2 anastomoses. The number of anastomoses did not negatively impact biliary complication rates. Recipients' major complication rate (Clavien ≥ 3b) was similar between both groups (1 BD versus 2 BD groups, 21% versus 24%, respectively; P = 0.36). Furthermore, no difference could be found between the 1 BD, the 2 BD, and the 3 BD groups in the frequency of developing biliary complications within 1 year (18%, 21%, 14%, respectively; P = 0.64), BD strictures (15%, 15%, 5%, respectively; P = 0.42), or BD leaks (10%, 11%, 10%, respectively; P = 0.98). In addition, the 1-year (90% versus 91%), 5-year (82% versus 77%), and 10-year (70% versus 66%) graft survival rates as well as the 1-year (92% versus 93%), 5-year (84% versus 80%), and 10-year (75% versus 76%) patient survival rates were comparable between the 1 BD and the 2 BD groups (P = 0.41 and P = 0.54, respectively). In conclusion, this study demonstrates that selected living donor grafts with 2 BDs can be used safely without negatively impacting biliary complication rates and graft or patient survival rates.

The liver is the largest solid organ in the body and is critical for metabolic and immune functions. However, little is known about the cells that make up the human liver and its immune microenvironment. Here we report a map of the cellular landscape of the human liver using single-cell RNA sequencing. We provide the transcriptional profiles of 8444 parenchymal and non-parenchymal cells obtained from the fractionation of fresh hepatic tissue from five human livers. Using gene expression patterns, flow cytometry, and immunohistochemical examinations, we identify 20 discrete cell populations of hepatocytes, endothelial cells, cholangiocytes, hepatic stellate cells, B cells, conventional and non-conventional T cells, NK-like cells, and distinct intrahepatic monocyte/macrophage populations. Together, our study presents a comprehensive view of the human liver at single-cell resolution that outlines the characteristics of resident cells in the liver, and in particular provides a map of the human hepatic immune microenvironment.

Portal vein thrombosis (PVT) is a severe complication after liver transplantation that can result in increased morbidity and mortality. Few data are available regarding risk factors, classification, and treatment of PVT after living donor liver transplantation (LDLT). Between January 2004 and November 2014, 421 adult-to-adult LDLTs were performed at our institution, and they were included in the analysis. Perioperative characteristics and outcomes from patients with no-PVT (n = 393) were compared with those with de novo PVT (total portal vein thrombosis [t-PVT]; n = 28). Ten patients had early portal vein thrombosis (e-PVT) occurring within 1 month, and 18 patients had late portal vein thrombosis (l-PVT) appearing later than 1 month after LDLT. Analysis of perioperative variables determined that splenectomy was associated with t-PVT (hazard ratio [HR], 3.55; P = 0.01), e-PVT (HR, 4.96; P = 0.04), and l-PVT (HR, 3.84; P = 0.03). In contrast, donor age was only found as a risk factor for l-PVT (HR, 1.05; P = 0.01). Salvage rate for treatment in e-PVT and l-PVT was 100% and 50%, respectively, without having an early event of rethrombosis. Mortality within 30 days did not show a significant difference between groups (no-PVT, 2% versus e-PVT, 10%; P = 0.15). No significant differences were found regarding 1-year (89% versus 92%), 5-year (79% versus 82%), and 10-year (69% versus 79%) graft survival between the t-PVT and no-PVT groups, respectively (P = 0.24). The 1-year (89% versus 96%), 5-year (82% versus 86%), and 10-year (79% versus 83%) patient survival was similar for the patients in the no-PVT and t-PVT groups, respectively (P = 0.70). No cases of graft loss occurred as a direct consequence of PVT. In conclusion, the early diagnosis and management of PVT after LDLT can lead to acceptable early and longterm results without affecting patient and graft survival.

Because of the shortfall between the number of patients listed for liver transplantation (LT) and the available grafts, strategies to expand the donor pool have been developed. Donation after circulatory death (DCD) and living donor (LD) grafts are not universally used because of the concerns of graft failure, biliary complications, and donor risks. In order to overcome the barriers for the implementation of using all 3 types of grafts, we compared outcomes after LT of DCD, LD, and donation after brain death (DBD) grafts. Patients who received a LD, DCD, or DBD liver graft at the University of Toronto were included. Between January 2009 through April 2017, 1054 patients received a LT at our center. Of these, 77 patients received a DCD graft (DCD group); 271 received a LD graft (LD group); and 706 received a DBD graft (DBD group). Overall biliary complications were higher in the LD group (11.8%) compared with the DCD group (5.2%) and the DBD group (4.8%; P < 0.001). The 1‐, 3‐, and 5‐year graft survival rates were similar between the groups with 88.3%, 83.2%, and 69.2% in the DCD group versus 92.6%, 85.4%, and 84.7% in the LD group versus 90.2%, 84.2%, and 79.9% in the DBD group (P = 0.24). Furthermore, the 1‐, 3‐, and 5‐year patient survival was comparable, with 92.2%, 85.4%, and 71.6% in the DCD group versus 95.2%, 88.8%, and 88.8% in the LD group versus 93.1%, 87.5%, and 83% in the DBD group (P = 0.14). Multivariate Cox regression analysis revealed that the type of graft did not impact graft survival. In conclusion, DCD, LD, and DBD grafts have similar longterm graft survival rates. Increasing the use of LD and DCD grafts may improve access to LT without affecting graft survival rates. Liver Transplantation 24 779–789 2018 AASLD.

Colorectal cancer (CRC) is the third most incident cancer worldwide. Most of CRC patients will develop distant metastases, mainly to the liver, and liver resection is the only potential chance for cure. On the other hand, only a small proportion of patients with hepatic CRC metastasis are candidates for upfront liver resection. Liver transplantation (LT) is an attractive option for patients with nonresectable CRC liver metastases (NRCLM) without extrahepatic involvement. Initial experiences with LT for NRCLM achieved very poor outcomes, with a 5-year overall survival (OS) lower than 20%. However, these initial studies did not have a standardized patient selection or neoadjuvant or adjuvant therapies. With recent advances in the surgical and medical oncology fields, the landscape has changed. Recent studies from Norway have shown an encouraging 5-year OS of 50% when transplanting patients with NRCLM. Nevertheless, the main concern when expanding the indications for LT is organ shortage. To manage this organ shortage, strategies utilizing live donor liver transplantation are gaining favor. A few ongoing trials are assessing the impact of LT in NRCLM patient survival. Therefore, the aim of this paper is to review the current status of LT for NRCLM.

Background & Aims In 2018, our team initiated a prospective pilot program to challenge the paradigm of the "6-month rule" of abstinence for patients with alcohol-related liver disease (ALD) requiring transplant. Our pilot involved an in-depth examination of patients' alcohol use, social support, and psychiatric comorbidity, as well as the provision of pre- and post-transplantation addiction treatment. Methods Patients with ALD were assessed for inclusion in the pilot by a multidisciplinary team. Relapse prevention therapy was provided directly to all patients deemed to meet the program's inclusion criteria. Random biomarker testing for alcohol was used pre and post transplantation. Results We received 703 referrals from May 1, 2018 to October 31, 2020. After fulfilling the program's criteria, 101 patients (14%) were listed for transplantation and 44 (6.2%) received transplants. There were no significant differences in survival rates between those receiving transplants through the pilot program compared with a control group with more than 6 months of abstinence (P = .07). Three patients returned to alcohol use during an average post-transplantation follow-up period of 339 days. In a multivariate analysis, younger age and lower Model for End-Stage Liver Disease scores at listing were associated with an increased likelihood of a return to alcohol use (P Conclusions Our prospective program provided direct monitoring and relapse prevention treatment for patients with ALD and with less than 6 months of abstinence and resulted in a reduction of post-transplantation return to drinking. This pilot study provides a framework for the future of more equitable transplant care.

Importance The Model for End-stage Liver Disease (MELD)-based organ allocation system has significantly decreased mortality on the transplant waiting list for patients with end-stage liver disease. However, women have remained at a disadvantage with respect to access to deceased donor liver transplant (DDLT) even after introduction of the MELD score for organ allocation. Objective To determine whether availability of living donation in a transplant program can offset inequity in liver transplant (LT) allocation for women. Design, Setting, and Participants This cohort study retrospectively analyzed adult patients listed for LT at the University Health Network in Toronto, Ontario, Canada. Patients included had a potential living donor (pLD) at the moment of listing. This study was performed from November 13, 2012, to May 31, 2019. A total of 1289 listed patients (830 men; 459 women) were analyzed during the study period. Main Outcomes and Measures This study performed survival analysis and competing-risk analysis to delineate how access to livers from living donors was associated with events in women vs men on the transplant waiting list (LT, death, or dropout). Results Of 1289 included patients, 459 (35.6%) were women, and the mean (SD) age was 56.1 (10.0) years at assessment and listing. A total of 783 of 1289 listed patients underwent LT. Among those with no pLD at assessment, there was a higher median (range) Model for End-stage Liver Disease incorporating sodium levels (MELD-Na) score at listing (22 [6-50] vs 19 [6-50]; P

Patients with hepatocellular carcinoma (HCC) beyond the traditional criteria (advanced HCC) are typically offered palliation, which is associated with a 3-year survival rate lower than 30%. This study aimed to describe the outcomes for a subset of patients with advanced HCC who satisfied the Extended Toronto Criteria (ETC) and were listed for liver transplantation (LT).All patients listed in the Toronto liver transplantation program with HCC beyond both the Milan and University of California, San Francisco criteria were included in this study. Data were extracted from the prospectively collected electronic database. All radiologic images were reviewed by two independent radiologists. The primary end point was patient survival.Between January 1999 and August 2014, 96 patients with advanced HCC were listed for LT, and 62 (65%) of these patients received bridging therapy while on the waiting list. Bridging therapy led to a significant reduction in tumor progression (p = 0.02) and tumor burden (p 0.001). The majority of those listed underwent LT (n = 69, 72%). Both tumor progression on waiting list (hazard ratio [HR] 4.973; range1.599-15.464; p = 0.006) and peak alpha-fetoprotein (AFP) at 400 ng/ml or higher (HR, 4.604; range 1.660-12.768; p = 0.003) were independently associated with waiting list dropout. Post-LT HCC recurrence occurred in 35% of the patients (n = 24). Among those with HCC recurrence, survival was significantly better for those who received curative treatment (p = 0.004). The overall actuarial survival rates from the listing were 76% at 1 year, 56% at 3 years, and 47% at 5 years, and the corresponding rates from LT were 93, 71, and 66%.Liver transplantation provides significantly better survival rates than palliation for patients with selected advanced HCC.

A significant challenge to delivering therapeutic doses of nanoparticles to targeted disease sites is the fact that most nanoparticles become trapped in the liver. Liver-resident macrophages, or Kupffer cells, are key cells in the hepatic sequestration of nanoparticles. However, the precise role that the macrophage phenotype plays in nanoparticle uptake is unknown. Here, we show that the human macrophage phenotype modulates hard nanoparticle uptake. Using gold nanoparticles, we examined uptake by human monocyte-derived macrophages that had been driven to a "regulatory" M2 phenotype or an "inflammatory" M1 phenotype and found that M2-type macrophages preferentially take up nanoparticles, with a clear hierarchy among the subtypes (M2c > M2 > M2a > M2b > M1). We also found that stimuli such as LPS/IFN-γ rather than with more "regulatory" stimuli such as TGF-β/IL-10 reduce per cell macrophage nanoparticle uptake by an average of 40%. Primary human Kupffer cells were found to display heterogeneous expression of M1 and M2 markers, and Kupffer cells expressing higher levels of M2 markers (CD163) take up significantly more nanoparticles than Kupffer cells expressing lower levels of surface CD163. Our results demonstrate that hepatic inflammatory microenvironments should be considered when studying liver sequestration of nanoparticles, and that modifying the hepatic microenvironment might offer a tool for enhancing or decreasing this sequestration. Our findings also suggest that models examining the nanoparticle/macrophage interaction should include studies with primary tissue macrophages.

The Toronto Video Atlas of Liver, Pancreas, Biliary, and Transplant Surgery (TVASurg) is a free online library of three-dimensional (3D) animation-enhanced surgical videos, designed to instruct surgical fellows in hepato-pancreato-biliary (HPB) and transplant procedures. The video ‘Klatskin tumours: Extended left hepatectomy with complex portal vein reconstruction and in situ cold perfusion of the liver’, which is available to watch at http://TVASurg.ca, is a unique and valuable visual resource for surgeons in training to assist them in learning this rare procedure. This paper describes the methodologies used in producing this 3D animation-enhanced surgical video.