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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.

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.

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 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.

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.

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.

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.

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.

Background Spleen preservation during distal pancreatectomy (SpDP) can be accomplished by a variety of surgical approaches, but the impact on spleen function is unknown. This study aimed to compare spleen volume, function and complications between patients who underwent vessel sparing (VSDP) vs. vessel ligating (Warshaw, WDP) SpDP. Methods All patients who underwent SpDP at the Toronto General Hospital from 2006 to 2015 were included. Primary outcomes were pre- and post-operative spleen volumes and contrast enhancement on CT, hematologic parameters, and spleen-related complications. Results 82 patients underwent SpDP with median follow up of 20.4 months. Splenic volumes were able to be calculated on 44 patients (VSDP n = 8, WDP n = 36). There was no difference between WDP and VSDP in operative duration, blood loss, hospital length of stay, or Clavien-Dindo ≥3 complication rate. Spleen volumes did not differ from baseline in either group. On postoperative imaging more WDP patients had areas of splenic hypoperfusion (p = 0.032). These differences resolved by 3 months after surgery, there were no instances of long term infectious or bleeding complications related to poor splenic function or gastric varices. Conclusion Both WDP and VSDP achieve splenic preservation. Neither technique resulted in clinically apparent spleen related complications. There is no difference in splenic volume and function in the short/long term.

Analyzing the mouse liver requires optimal cell recovery from the tissue in terms of quality (viability) and quantity. Harsh dissociation methods can damage fragile cell populations, resulting in low viability and difficulty in cell culture. We have developed a gentle surgical and enzymatic technique based on the two-step collagenase perfusion protocol for single-cell analysis and primary cell culture.

Summary Liver sinusoidal endothelial cells (LSECs) form a highly specialized microvasculature that plays a critical role in liver function and disease. To better understand this role, we developed a strategy to generate LSECs from human pluripotent stem cells (hPSCs) by first optimizing the specification of arterial and venous angioblasts and derivative endothelial populations. Induction of a LSEC-like fate by hypoxia, cyclic AMP (cAMP) agonism, and transforming growth factor β (TGF-β) inhibition revealed that venous endothelial cells responded more rapidly and robustly than the arterial cells to upregulate LSEC markers and functions in vitro. Upon intrahepatic transplantation in neonates, venous angioblasts engrafted the liver and generated mature, fenestrated LSECs with scavenger functions and molecular profiles of primary human LSECs. When transplanted into the liver of adult mice, angioblasts efficiently gave rise to mature LSECs with robust factor VIII (FVIII) production. Humanization of the murine liver with hPSC-derived LSECs provides a tractable system for studying the biology of this key liver cell type.

Objective: To report the role of liver transplantation in the management of refractory carcinoid syndrome. Methods: We describe the clinical course, biochemical, radiographic, and histopathologic features of a patient with severe refractory carcinoid syndrome due to a metastatic well-differentiated enterochromaffin cell neuroendocrine tumor of the jejunum. We also review and summarize the literature on liver transplantation in this setting. Results: An 18-year-old patient presented with a 3-year history of progressive palpitations, flushing, abdominal pain, and diarrhea. Initial imaging studies demonstrated multiple cystic liver lesions; biochemistry confirmed elevated 24-hour urinary 5-hydroxy-indolacetic acid (5-HIAA) levels. She was managed with somatostatin analogues followed by a partial small-bowel resection. Five sessions of liver embolization and escalating somatostatin analogues failed to control her symptoms or normalize urinary 5-HIAA levels. Cross-sectional imaging detected disease only in the liver. Due to progressively worsening symptoms, liver transplantation was offered as a therapeutic option at age 21 years. One year following the procedure, her condition improved clinically and biochemically with minimal disease outside the liver. Conclusion: Liver transplantation represents a potential therapeutic option in selected patients with refractory carcinoid syndrome.

Background The use of venovenous bypass in liver transplantation has declined over time. Few studies have examined the impact of surgical approach in cases performed exclusively without venovenous bypass. We hypothesized that advances in liver transplant anesthesia and perioperative care have minimized the importance of surgical approach in the modern era. Methods Deceased donor liver transplants at the University of Toronto from 2000 to 2015 were reviewed, all performed without venovenous bypass. First, an unadjusted analysis was performed comparing perioperative outcomes and graft/patient survival for 3 different liver transplant techniques (caval interposition, piggyback, side-to-side cavo-cavostomy). Second, a propensity-matched analysis was performed comparing caval interposition to caval-preserving techniques. Results One thousand two hundred thirty-three liver transplants were included in the study. On unadjusted analysis, blood loss, transfusion requirement, postoperative complications, and graft/patient survival were equivalent for the 3 different techniques. To account for possible confounding patient variables, propensity matching was performed. Analysis of the propensity-matched cohorts also demonstrated similar outcomes for caval interposition versus caval-preserving approaches. Conclusions In the modern era at centers with a multidisciplinary team, the importance of specific liver transplant technique is minimized. Full or partial cross-clamping of the inferior vena cava is feasible without the use of venovenous bypass.

Non-alcoholic fatty liver disease (NAFLD), especially non-alcoholic steatohepatitis (NASH) is a chronic liver disease commonly associated with hepatic fibrosis. NASH patients have an increased risk for hepatocellular carcinoma (HCC). An altered retinol metabolism is one of the pathways involved in the process of hepatic fibrosis, and enzymes involved in retinol metabolism have been associated with HCC. We aimed to determine the association between plasma retinol levels and hepatic expression of genes related to retinol metabolism, as well as to assess the hepatic expression of transcription factors regulated by retinoic acid in patients with NAFLD. Cross-sectional study where hepatic gene expression (Illumina microarray) and plasma retinol levels (HPLC) were measured in 17 patients with simple steatosis (SS), 15 with NASH, and 22 living liver donors (LD) as controls. Plasma retinol levels were higher in SS (1.53 ± 0.44 μmol/L) and NASH (1.51 ± 0.56 μmol/L) compared to LD (1.21 ± 0.38 μmol/L; p

The purpose of this case report is to describe a patient with a preoperative complex pain syndrome who underwent liver transplantation and was able to reduce his opioid consumption significantly following the initiation of treatment with medical cannabis.A 57-yr-old male with a history of hepatitis C cirrhosis underwent liver transplantation. Preoperatively, he was taking hydromorphone 2-8 mg⋅day(-1) for chronic abdominal pain. Postoperatively, he was given intravenous patient-controlled analgesia through which he received hydromorphone 30 mg⋅day(-1). Our multidisciplinary Transitional Pain Service was involved with managing his moderate to severe acute postsurgical pain in hospital and continued with weaning him from opioid medications after discharge. It was difficult to wean the patient from opioids, and he was subsequently given medical cannabis at six weeks postoperatively with remarkable effect. By the fifth postoperative month, his use of opioids had tapered to 6 mg⋅day(-1) of hydromorphone, and his functional status was excellent on this regimen.Reductions in opioid consumption were achieved with the administration of medical cannabis in a patient with acute postoperative pain superimposed on a chronic pain syndrome and receiving high doses of opioids. Concurrent benefits of initiating medical cannabis may include improvements in pain profile and functional status along with reductions in opioid-related side effects. This highlights the potential for medical cannabis as an adjunct medication for weaning patients from opioid use.

Because of a persistent discrepancy between the demand for liver transplantation (LT) and the supply of deceased donor organs, there is an interest in increasing living donation rates at centers trained in this method of transplantation. We examined a large socioeconomically heterogeneous cohort of patients listed for LT to identify recipient factors associated with living donation. We retrospectively reviewed 491 consecutive patients who were listed for LT at our center over a 24-month period. Demographic, medical, and socioeconomic data were extracted from electronic records and compared between those who had a potential living donor (LD) volunteer for assessment and those who did not; 245 patients (50%) had at least 1 potential LD volunteer for assessment. Multivariate logistic regression analysis identified that patients with a LD were more likely to have Child-Pugh C disease (odds ratio [OR], 2.44; P = 0.02), and less likely to be older (OR, 0.96; P = 0.002), single (OR, 0.34; P = 0.006), divorced (OR, 0.53; P = 0.03), immigrants (OR, 0.38; P = 0.049), or from the lowest income quintile (OR, 0.44; P = 0.02). In conclusion, this analysis has identified several factors associated with access to living donation. More research is warranted to define and overcome barriers to living donor liver transplantation through targeted interventions in underrepresented populations. Liver Transpl 21:897-903, 2015. © 2015 AASLD.

Data regarding transplantation outcomes in ventilated intensive care unit (ICU)–dependent patients with end-stage liver disease (ESLD) are conflicting. This single-center cohort study investigated the outcomes of patients with ESLD who were intubated with mechanical support before liver transplantation (LT). The ICU plus intubation group consisted of 42 patients with decompensated cirrhosis and mechanical ventilation before transplantation. LT was considered for intubated ICU patients if the fraction of inspired oxygen was ≤40% with a positive end-expiratory pressure ≤ 10, low pressor requirements, and the absence of an active infection. Intubated ICU patients were compared to 80 patients requiring ICU admission before transplantation without intubation and to 126 matched non–ICU-bound patients. Patients requiring ICU care with intubation and ICU care alone had more severe postoperative complications than non–ICU-bound patients. Intubation before transplantation was associated with more postoperative pneumonias (15% in intubated ICU transplant candidates, 5% in ICU-bound but not intubated patients, and 3% in control group patients; P = 0.02). Parameters of reperfusion injury and renal function on postoperative day (POD) 2 and POD 7 were similar in all groups. Bilirubin levels were higher in the ICU plus intubation group at POD 2 and POD 7 after transplantation but were normalized in all groups within 3 months. The ICU plus intubation group versus the ICU-only group and the non-ICU group had decreased 1-, 3-, and 5-year graft survival (81% versus 84% versus 92%, 76% versus 78% versus 87%, and 71% versus 77% versus 84%, respectively; P = 0.19), but statistical significance was not reached. A Glasgow coma scale score of 7 before transplantation was associated with high postoperative mortality in ICU-bound patients requiring intubation (38% versus 23%; P = 0.01). In conclusion, ICU admission and mechanical ventilation should not be considered contraindications for LT. With careful patient selection, acceptable long-term outcomes can be achieved despite increased postoperative complications. Liver Transpl 21:761–767, 2015. © 2015 AASLD.

In nonalcoholic fatty liver disease, hepatic gene expression and fatty acid (FA) composition have been reported independently, but a comprehensive gene expression profiling in relation to FA composition is lacking. The aim was to assess this relationship. In a cross-sectional study, hepatic gene expression (Illumina Microarray) was first compared among 20 patients with simple steatosis (SS), 19 with nonalcoholic steatohepatitis (NASH), and 24 healthy controls. The FA composition in hepatic total lipids was compared between SS and NASH, and associations between gene expression and FAs were examined. Gene expression differed mainly between healthy controls and patients (SS and NASH), including genes related to unsaturated FA metabolism. Twenty-two genes were differentially expressed between NASH and SS; most of them correlated with disease severity and related more to cancer progression than to lipid metabolism. Biologically active long-chain polyunsaturated FAs (PUFAs; eicosapentaenoic acid + docosahexaenoic acid, arachidonic acid) in hepatic total lipids were lower in NASH than in SS. This may be related to overexpression of FADS1, FADS2, and PNPLA3. The degree and direction of correlations between PUFAs and gene expression were different among SS and NASH, which may suggest that low PUFA content in NASH modulates gene expression in a different way compared with SS or, alternatively, that gene expression influences PUFA content differently depending on disease severity (SS versus NASH). Conclusion: Well-defined subjects with either healthy liver, SS, or NASH showed distinct hepatic gene expression profiles including genes involved in unsaturated FA metabolism. In patients with NASH, hepatic PUFAs were lower and associations with gene expression were different compared to SS. (Hepatology 2015;61:1565–1578)

Liver transplantation (LT) with donation after circulatory death (DCD) donors has been associated with a high rate of ischemic-type biliary strictures (ITBSs) and inferior graft survival. To investigate the impact of an intraoperative tissue plasminogen activator (tPA) on outcomes following DCD LT, we conducted a retrospective analysis of DCD LT at the Toronto General Hospital (TGH) and the Ochsner Medical Center (OMC). Between 2009 and 2013, 85 DCD LTs were performed with an intraoperative tPA injection (n=30 at TGH, n=55 at OMC), and they were compared with 33 DCD LTs without a tPA. Donor and recipient characteristics were similar in the 2 groups. There was no significant difference in the intraoperative packed red blood cell transfusion requirement (3.2 +/- 3.4 versus 3.1 +/- 2.3 U, P=0.74). Overall, biliary strictures occurred less commonly in the tPA-treated group (16.5% versus 33.3%, P=0.07) with a much lower rate of diffuse intrahepatic strictures (3.5% versus 21.2%, P=0.005). After 1 and 3 years, the tPA group versus the non-tPA group had superior patient survival (97.6% versus 87.0% and 92.7% versus 79.7%, P=0.016) and graft survival (96.4% versus 69.7% and 90.2% versus 63.6%, P

Background Duodenal leak remains a major cause of morbidity and graft loss in pancreas transplant recipients. The role and efficacy of surgical and image-guided interventions to salvage enterically drained grafts with a duodenal leak has yet to be defined. Methods We investigated the incidence, treatment, and outcome of duodenal leak in 426 pancreas transplantation recipients from 2000 to 2015. Results Duodenal leak developed in 33 (7.8%) recipients after a median follow-up of 5.3 (range, 0.5-15.2) years. Most leaks occurred during the first year (n = 22; 67%), and most were located near the proximal and distal duodenal staple line. Graft pancreatectomy was performed in 8 patients as primary therapy because of unfavorable local and/or systemic conditions. Salvage was attempted in 25 patients using percutaneous drainage (n = 4), surgical drainage (n = 4), or surgical repair (n = 17). Percutaneous or surgical drainage failed to control the leak in 7 of these 8 patients, and all 7 ultimately required graft pancreatectomy for persistent leak and sepsis. Surgical repair salvaged 14 grafts, and 13 grafts continue to function after a median follow-up of 2.9 (range, 1.1-6.3) years after repair. Conclusions Our study shows that in selected patients a duodenal leak can be repaired successfully and safely in enterically drained grafts.

Oncolytic viruses are cancer therapeutics with promising outcomes in pre-clinical and clinical settings. Animal viruses have the possibility to avoid pre-existing immunity in humans, while being safe and immunostimulatory. We isolated an avian orthoreovirus (ARV-PB1), and tested it against a panel of hepatocellular carcinoma cells. We found that ARV-PB1 replicated well and induced strong cytopathic effects. It was determined that one mechanism of cell death was through syncytia formation, resulting in apoptosis and induction of interferon stimulated genes (ISGs). As hepatitis C virus (HCV) is a major cause of hepatocellular carcinoma worldwide, we investigated the effect of ARV-PB1 against cells already infected with this virus. Both HCV replicon-containing and infected cells supported ARV-PB1 replication and underwent cytolysis. Finally, we generated in silico models to compare the structures of human reovirus- and ARV-PB1-derived S1 proteins, which are the primary targets of neutralizing antibodies. Tertiary alignments confirmed that ARV-PB1 differs from its human homolog, suggesting that immunity to human reoviruses would not be a barrier to its use. Therefore, ARV-PB1 can potentially expand the repertoire of oncolytic viruses for treatment of human hepatocellular carcinoma and other malignancies.

Visualizing the complex anatomy of vascular and biliary structures of the liver on a case-by-case basis has been challenging. A living donor liver transplant (LDLT) right hepatectomy case, with focus on the porta hepatis, was used to demonstrate an innovative method to visualize anatomy with the purpose of refining preoperative planning and teaching of complex surgical procedures. The production of an animation-enhanced video consisted of many stages including the integration of pre-surgical planning; case-specific footage and 3D models of the liver and associated vasculature, reconstructed from contrast-enhanced CTs. Reconstructions of the biliary system were modeled from intraoperative cholangiograms. The distribution of the donor portal veins, hepatic arteries and bile ducts was defined from the porta hepatis intrahepatically to the point of surgical division. Each step of the surgery was enhanced with 3D animation to provide sequential and seamless visualization from pre-surgical planning to outcome. Use of visualization techniques such as transparency and overlays allows viewers not only to see the operative field, but also the origin and course of segmental branches and their spatial relationships. This novel educational approach enables integrating case-based operative footage with advanced editing techniques for visualizing not only the surgical procedure, but also complex anatomy such as vascular and biliary structures. The surgical team has found this approach to be beneficial for preoperative planning and clinical teaching, especially for complex cases. Each animation-enhanced video case is posted to the open-access Toronto Video Atlas of Surgery (TVASurg), an education resource with a global clinical and patient user base. The novel educational system described in this paper enables integrating operative footage with 3D animation and cinematic editing techniques for seamless sequential organization from pre-surgical planning to outcome.

Whether and when recovery beyond the need for transplant may occur in patients listed for decompensation remains unclear. This study aimed to investigate the characteristics of patients delisted following recompensation. Seventy-seven patients who were listed between 2005 and 2015 for decompensation, but later delisted following recompensation were included. Alcohol-related liver disease (ALD) was the underlying etiology in the majority (n = 47, 61%). Listing characteristics of these patients were compared with those of decompensated ALD patients who either underwent deceased donor liver transplantation or died on the waiting list. The model for end-stage liver disease (MELD) score