Exacerbated ischemia-reperfusion injury in fatty livers is mediated by lipid peroxidation stress and ferroptosis.

BACKGROUND: Ischemia-reperfusion injury is a common problem in liver surgery and transplantation. Although ischemia-reperfusion injury is known to be more pronounced in fatty livers, the underlying mechanisms for this difference remain poorly understood. We hypothesized that ferroptosis plays a significant role in fatty liver ischemia-reperfusion injury due to increased lipid peroxidation in the presence of stored iron in the fatty liver. To test this hypothesis, the ferroptosis pathway was evaluated in a murine fatty liver ischemia-reperfusion injury model. METHODS: C57BL6 mice were fed with a normal diet or a high fat, high sucrose diet for 12 weeks. At 22 weeks of age, liver ischemia-reperfusion injury was induced through partial (70%) hepatic pedicle clamping for 60 minutes, followed by 24 hours of reperfusion before tissue harvest. Acyl-coenzyme A synthetase long-chain family member 4 and 4-hydroxynonenal were quantified in the liver tissues. In separate experiments, liproxstatin-1 or vehicle control was administered for 7 consecutive days before liver ischemia-reperfusion injury. RESULTS: Exacerbated ischemia-reperfusion injury was observed in the livers of high fat, high sucrose diet fed mice. High fat, high sucrose diet + ischemia-reperfusion injury (HDF+IRI) livers had a significantly greater abundance of acyl-coenzyme A synthetase long-chain family member 4 and 4-hydroxynonenal compared with normal diet + ischemia-reperfusion injury (ND+IRI) livers or sham fatty livers, which indicated an increase of ferroptosis. HFD fed animals receiving liproxstatin-1 injections had a significant reduction in serum aspartate transaminase and alanine transaminase after ischemia-reperfusion injury, consistent with attenuation of ischemia-reperfusion injury in the liver. CONCLUSION: Ferroptosis plays a significant role in ischemia-reperfusion injury in fatty livers. Inhibiting ferroptotic pathways in the liver may serve as a novel therapeutic strategy to protect the fatty liver in the setting of ischemia-reperfusion injury.

Successful Sequential Liver and Isolated Intestine Transplantation for Mitochondrial Neurogastrointestinal Encephalopathy Syndrome: A Case Report.

BACKGROUND Mitochondrial neurogastrointestinal encephalopathy syndrome (MNGIE) is an autosomal recessive disease caused by thymidine phosphorylase deficiency leading to progressive gastrointestinal dysmotility, cachexia, ptosis, ophthalmoparesis, peripheral neuropathy and leukoencephalopathy. Although liver transplantation corrects thymidine phosphorylase deficiency, intestinal deficiency of the enzyme persists. Retrospective chart review was carried out to obtain clinical, biochemical, and pathological details. CASE REPORT We present a case of liver and subsequent intestine transplant in a 28-year-old man with MNGIE syndrome with gastrointestinal dysmotility, inability to walk, leukoencephalopathy, ptosis, cachexia, and elevated serum thymidine. To halt progression of neurologic deficit, he first received a left-lobe partial liver transplantation. Although his motor deficit improved, gastrointestinal dysmotility persisted, requiring total parenteral nutrition. After exhaustive intestinal rehabilitation, he was listed for intestine transplantation. Two-and-half years after liver transplantation, he received an intestine transplant. At 4 years after LT and 20 months after the intestine transplant, he remains off parenteral nutrition and is slowly gaining weight. CONCLUSIONS This is the first reported case of mitochondrial neurogastrointestinal encephalomyopathy to undergo successful sequential liver and intestine transplantation.

Optimization of Kidney Health in Liver Transplant Candidates: Pretransplant Considerations and Modalities.

Patients with decompensated end-stage liver disease (ESLD) are at increased risk for mortality, and only liver transplantation (LT) offers meaningful hope for survival. These patients are at risk for kidney dysfunction through the continuum of care for ESLD including LT. We discuss the role of accurate estimation and measurement of baseline glomerular filtration rate in assessment of kidney dysfunction among those with ESLD. Optimizing kidney function is a vital goal in the management of these patients before LT. In this review, we summarize salient aspects of assessing and optimizing kidney function in this patient population. Precipitating factors and different causes of acute kidney injury are discussed, including hepatorenal syndrome. We further review treatment options for acute kidney injury including volume management. The role of vasopressor therapy, renal replacement therapy, and transjugular intrahepatic portosystemic shunting are discussed.

Plasma exchange for acute and acute-on-chronic liver failure: A systematic review and meta-analysis.

Plasma exchange (PE) is a promising therapeutic option in patients with acute liver failure (ALF) and acute-on-chronic liver failure (ACLF). However, the impact of PE on patient survival in these syndromes is unclear. We aimed to systematically investigate the use of PE in patients with ALF and ACLF compared with standard medical therapy (SMT). We searched PubMed/Embase/Cochrane databases to include all studies comparing PE versus SMT for patients ≥ 18 years of age with ALF and ACLF. Pooled risk ratios (RR) with corresponding 95% CIs were calculated by the Mantel-Haenszel method within a random-effect model. The primary outcome was 30-day survival for ACLF and ALF. Secondary outcomes were overall and 90-day survival for ALF and ACLF, respectively. Five studies, including 343 ALF patients (n = 174 PE vs. n = 169 SMT), and 20 studies, including 5,705 ACLF patients (n = 2,856 PE vs. n = 2,849 SMT), were analyzed. Compared with SMT, PE was significantly associated with higher 30-day (RR 1.41, 95% CI 1.06-1.87, p = 0.02) and overall (RR 1.35, 95% CI 1.12-1.63, p = 0.002) survival in ALF patients. In ACLF, PE was also significantly associated with higher 30-day (RR 1.36, 95% CI 1.22-1.52, p < 0.001) and 90-day (RR 1.21, 95% CI 1.10-1.34, p < 0.001) survival. On subgroup analysis of randomized controlled trials, results remained unchanged in ALF, but no differences in survival were found between PE and SMT in ACLF. In conclusion, PE is associated with improved survival in ALF and could improve survival in ACLF. PE may be considered in managing ALF and ACLF patients who are not liver transplant (LT) candidates or as a bridge to LT in otherwise eligible patients. Further randomized controlled trials are needed to confirm the survival benefit of PE in ACLF.

Severe hepatic encephalopathy with mechanical ventilation may inform waitlist priority in acute liver failure: A UNOS database analysis.

BACKGROUND & AIMS: Patients with acute liver failure (ALF) awaiting liver transplantation (LT) may develop multiorgan failure, but organ failure does not impact waitlist prioritization. The aim of this study was to examine the impact of organ failure on waitlist mortality risk and post LT outcomes in patients with ALF. METHODS: We studied adults waitlisted for ALF in the United Network for Organ Sharing (UNOS) database (2002-2019). Organ failures were defined using a previously described Chronic Liver Failure modified sequential organ failure score assessment adapted to UNOS data. Regression analyses of the primary endpoints, 30-day waitlist mortality (Competing risk), and post-LT mortality (Cox-proportional hazards), were performed. Latent class analysis (LCA) was used to determine the organ failures most closely associated with 30-day waitlist mortality. RESULTS: About 3212 adults with ALF were waitlisted, for hepatotoxicity (41%), viral (12%) and unspecified (36%) etiologies. The median number of organ failures was three (interquartile range 1-3). Having ≥3 organ failures (vs. ≤2) was associated with a sub hazard ratio (HR) of 2.7 (95%CI 2.2-3.4)) and a HR of 1.5 (95%CI 1.1-2.5)) for waitlist and post-LT mortality, respectively. LCA identified neurologic and respiratory failure as most impactful on 30-day waitlist mortality. The odds ratios for both organ failures (vs. neither) were higher for mortality 4.5 (95% CI 3.4-5.9) and lower for delisting for spontaneous survival .5 (95%CI .4-.7) and LT .6 (95%CI .5-.7). CONCLUSION: Cumulative organ failure, especially neurologic and respiratory failure, significantly impacts waitlist and post-LT mortality in patients with ALF and may inform risk-prioritized allocation of organs.

Deceased Donor Flush Volume Similar for Histidine-Tryptophan-Ketoglutarate and University of Wisconsin at a Single US Organ Procurement Organization: Adult and Pediatric Data.

BACKGROUND: Histidine-tryptophan-ketoglutarate (HTK) and University of Wisconsin (UW) solutions are the two primary solid-organ preservation solutions used in the United States (>95%), but flush volumes vary markedly by region and center. This study analyzes data from a single organ procurement organization (OPO) to determine the actual clinical flush volumes used for HTK and UW for liver and pancreas grafts. METHODS: All procurements at Indiana Donor Network were analyzed (2016-2020), and data were extracted from the on-site records. Variables included procuring center, solution, volumes, and vessels flushed. Brand and generic versions were considered equivalent. No clinical transplant outcomes were available. RESULTS: Data were analyzed from 875 liver and 192 pancreas procurements by over 70 U.S. centers representing 10 of 11 UNOS regions. The large majority of liver grafts were preserved with HTK (n=810, 93%; UW n=93, 7%). All liver donors received an aortic flush (100%), while portal vein flush was 14% in-situ and 88% back table. For liver grafts, the median volume of infused solution was less for HTK when compared to UW (4225mL vs 5500mL, p=0.04). For pancreas procurement, 100% received aortic flush of the graft, with median HTK and UW volumes being equivalent (3000mL; p=0.85). Pediatric organs were flushed with markedly higher weight-based volumes. CONCLUSIONS: Flush volumes for HTK and UW are similar at one midwestern OPO, with data comprised of procurements performed by centers from across the U.S. These data demonstrate that low-volume HTK flush is commonly used, and this practice may be considered as a cost-saving measure.

Comparative analysis of whole vs. split liver transplantation in infants.

BACKGROUND: Liver transplantation (LT) in infants can be challenging due to their small size and small vasculature. Although both whole LT (WLT) and split LT (SLT) have been described in infants, the head-to-head comparison of these techniques in this population is sparse. METHODS: We retrospectively analyzed the records of all patients with age ≤1 year at Indiana University between 2016 and 2022. All SLT were left lateral segment grafts split in situ. RESULTS: A total of 24 infants were transplanted, with 11 SLT and 13 WLT. The median follow-up time was 52.1 months. Donor and recipient characteristics were comparable except for donor age (19 years vs. 2 years; p < .01) and weight (64 kg vs. 14.2 kg; p < .01). Early allograft dysfunction, primary nonfunction, and hepatic artery thrombosis developed more frequently in the WLT group. There were no biliary complications. There were two early deaths (2 and 4 days) in the WLT group. One-year graft survival (100% vs. 77%; p = .10) and patient survival (100% vs. 85%; p = .18) were numerically higher in the SLT group. CONCLUSIONS: SLT with LLS offers a safe and viable option for liver transplantation in infants and is associated with a trend toward superior outcomes. SLT should be considered as a strategy to reduce waitlist times for infants in the absence of small, deceased donors for WLT.

Normothermic Machine Perfusion of Donor Livers for Transplantation in the United States: A Randomized Controlled Trial.

OBJECTIVE: To compare conventional low-temperature storage of transplant donor livers [static cold storage (SCS)] with storage of the organs at physiological body temperature [normothermic machine perfusion (NMP)]. BACKGROUND: The high success rate of liver transplantation is constrained by the shortage of transplantable organs (eg, waiting list mortality >20% in many centers). NMP maintains the liver in a functioning state to improve preservation quality and enable testing of the organ before transplantation. This is of greatest potential value with organs from brain-dead donor organs (DBD) with risk factors (age and comorbidities), and those from donors declared dead by cardiovascular criteria (donation after circulatory death). METHODS: Three hundred eighty-three donor organs were randomized by 15 US liver transplant centers to undergo NMP (n = 192) or SCS (n = 191). Two hundred sixty-six donor livers proceeded to transplantation (NMP: n = 136; SCS: n = 130). The primary endpoint of the study was "early allograft dysfunction" (EAD), a marker of early posttransplant liver injury and function. RESULTS: The difference in the incidence of EAD did not achieve significance, with 20.6% (NMP) versus 23.7% (SCS). Using exploratory, "as-treated" rather than "intent-to-treat," subgroup analyses, there was a greater effect size in donation after circulatory death donor livers (22.8% NMP vs 44.6% SCS) and in organs in the highest risk quartile by donor risk (19.2% NMP vs 33.3% SCS). The incidence of acute cardiovascular decompensation at organ reperfusion, "postreperfusion syndrome," as a secondary outcome was reduced in the NMP arm (5.9% vs 14.6%). CONCLUSIONS: NMP did not lower EAD, perhaps related to the inclusion of lower-risk liver donors, as higher-risk donor livers seemed to benefit more. The technology is safe in standard organ recovery and seems to have the greatest benefit for marginal donors.

Pleural Effusion and Malnutrition Are Associated With Worse Early Outcomes After Liver Transplant.

INTRODUCTION: Pulmonary complications after liver transplantation (LT) have previously been associated with longer hospital stays and ventilator time, and higher mortality. This study reports the outcomes for a specific pulmonary complication, pleural effusion, in LT recipients. METHODS: Records from a single transplant center were analyzed retrospectively for all adult LT patients. Patients with documented pleural effusion by radiographic imaging within 30 days pre- or post-transplant were considered as cases. Outcomes included length of hospital stay, discharge disposition, hospital readmission, discharge with home oxygen, and 1-year survival. RESULTS: During the 4-year study period, 512 LTs were performed, with 107 patients (21%) developing a peri-transplant pleural effusion. In total, 49 patients (10%) had a pre-transplant effusion, 91 (18%) had a post-transplant effusion, and 32 (6%) had both. Characteristics associated with the presence of any pleural effusion included an increasing model for end-stage liver disease score, re-transplantation, diagnosis of alcoholic liver disease, low protein levels, and sarcopenia. Effusion patients had longer hospital stays (17 vs 9 days, P < .001) and higher likelihood of discharge to a care facility (48% vs 21%, P < .001). Ninety-day readmission occurred in 69% of effusion patients (vs 44%, P < .001). One-year patient survival with any effusion was 86% (vs 94%, P < .01). CONCLUSIONS: Overall, 21% of recipients developed a clinically significant peri-transplant pleural effusion. Pleural effusion was associated with worse outcomes for all clinical measures. Risk factors for the development of pleural effusion included higher MELD score (>20), re-transplantation, alcoholic liver disease, and poor nutrition status, including poor muscle mass.

Cirrhotic cardiomyopathy: Predictors of major adverse cardiac events and assessment of reversibility after liver transplant.

BACKGROUND: Major adverse cardiac events (MACE) are a leading cause of morbidity and mortality after orthotopic liver transplantation (OLT). Cirrhotic cardiomyopathy (CCM), initially described in 2005 and revised in 2019, is a source of MACE in patients after OLT. We sought to identify CCM-related predictors of MACE at one-year follow-up after OLT and assess for reversibility of CCM post-OLT. METHODS: This is a retrospective study of adult patients who underwent OLT between 2009 and 2019. All patients had transthoracic echocardiography pre-and post-OLT. Patients with a left ventricular ejection fraction <50 % pre-OLT were excluded. MACE was defined as death, myocardial infarction, congestive heart failure hospitalization, or cardiac arrest. RESULTS: In total, 131 patients were included in this study, of whom 103 and 23 patients met the 2005 and 2019 criteria, respectively. During the follow-up period, 42 patients had MACE and these patients were more likely to have ascites (p = 0.003), hepatorenal syndrome (p = 0.019), and CCM per 2005 criteria (p = 0.023). There were no significant differences between pre-OLT CCM per 2019 criteria (19 % vs 17 %, p = 0.758) or MELD-Na score (21.24 vs 19.40, p = 0.166) for MACE post-OLT. Per the 2005 criteria, 35 of 103 patients recovered and these patients were less likely to have MACE post-OLT (p = 0.012). Per the 2019 criteria, 13 of 23 patients recovered post-OLT but this low number precluded further statistics. CONCLUSION: The 2005 Montreal criteria for CCM were an independent predictor of MACE at one-year follow-up post-OLT while the 2019 CCC criteria for CCM were not. In addition, the 2005 Montreal criteria were more prevalent when compared to 2019 CCC criteria. Finally, the 2005 Montreal criteria were reversible post-OLT 34 % of the time compared to the 2019 CCC criteria which were reversible 57 % of the time.

Assessment of Vascular and Valvular Calcification Improves Screening for Coronary Artery Disease Before Liver Transplantation.

Coronary artery disease (CAD) is common in patients with cirrhosis who underwent orthotopic liver transplantation (OLT) evaluation and stress echocardiogram (echo) has a low sensitivity in these patients. This study aimed to assess the impact of vascular and valvular calcification on the ability to identify CAD before OLT. We performed a case-control study of 88 patients with and 97 without obstructive CAD who underwent OLT evaluation. All patients had a preoperative stress echo, abdominal computed tomography, and cardiac catheterization. A series of nested logistic regression models of CAD were fit by adding independent variables of vascular (including coronary) calcification, aortic and mitral valve calcification, age, gender, and history of diabetes mellitus requiring insulin to a baseline model of abnormal stress echo. Compared with stress echo alone, identification of the presence or absence of vascular and valvular calcification on routine preoperative computed tomography and echo improved the diagnostic performance for the detection of CAD based on coronary angiogram when combined with stress echo in patients with cirrhosis who underwent OLT evaluation (area under the curve 0.58 vs 0.73, p <0.001), which is even further improved when age, gender, and history of diabetes mellitus requiring insulin are considered (area under the curve 0.58 vs 0.80, p <0.001). Achieving target heart rate (p = 0.92) or rate-pressure product >25,000 (p = 0.63) did not improve the ability of stress echo to identify CAD. In conclusion, the use of abdominal vascular, coronary artery, and valvular calcification, along with stress echo, improves the ability to identify and rule out obstructive CAD before OLT compared with stress echo alone.

Hepatic Ischemia/Reperfusion Injury After Liver Transplantation Is Not Associated with Early Impairment of Left Ventricular Ejection Fraction.

BACKGROUND Early myocardial dysfunction is a known complication following liver transplant. Although hepatic ischemia/reperfusion injury (hIRI) has been shown to cause myocardial injury in rat and porcine models, the clinical association between hIRI and early myocardial dysfunction in humans has not yet been established. We sought to define this relationship through cardiac evaluation via transthoracic echocardiography (TTE) on postoperative day (POD) 1 in adult liver transplant recipients. MATERIAL AND METHODS TTE was performed on POD1 in all liver transplant patients transplanted between January 2020 and April 2021. Hepatic IRI was stratified by serum AST levels on POD1 (none: <200; mild: 200-2000; moderate: 2000-5000; severe: >5000). All patients had pre-transplant TTE as part of the transplant evaluation. RESULTS A total of 173 patients underwent liver transplant (LT) between 2020 and 2021 and had a TTE on POD 1 (median time to echo: 1 day). hIRI was present in 142 (82%) patients (69% mild, 8.6% moderate, 4% severe). Paired analysis between pre-LT and post-LT left ventricular ejection fraction (LVEF) of the entire study population demonstrated no significant decrease following LT (mean difference: -1.376%, P=0.08). There were no significant differences in post-LT LVEF when patients were stratified by severity of hIRI. Three patients (1.7%) had significant post-transplant impairment of LVEF (<35%). None of these patients had significant hIRI. CONCLUSIONS hIRI after liver transplantation is not associated with immediate reduction in LVEF. The pathophysiology of post-LT cardiomyopathy may be driven by extra-hepatic triggers.

Liver Transplantation in Recipients With Class III Obesity: Posttransplant Outcomes and Weight Gain.

BACKGROUND: There has been a dramatic increase in obesity in the United States. Several studies have reported conflicting results for the impact of obesity on outcomes of liver transplantation (LT). This study aims to assess the impact of obesity on LT and changes in body mass index (BMI) after transplantation. METHODS: All adult LTs performed at Indiana University between 2001 and 2018 were reviewed. BMIs of recipients were subdivided into 6 categories. Survival outcomes were compared across the subgroup. BMI was followed up in a cohort of patients from 2008 to 2018. RESULTS: Among 2024 patients, 25% were in class I obesity, 9.3% were in class II obesity, and 1.1% were in class III obesity. There was no significant difference in patient and graft survival at 10-y follow-up with respect to BMI. Among 1004 patients in the subgroup, BMI of all groups except the underweight group declined in the first 3 mo postoperatively; however, the BMI of all groups except the class III obesity group returned to the pre-LT level by 2 y and reached a plateau by 5 y. In the class III obesity group, there was a significant increase in body weight at 5 y. CONCLUSIONS: Class III obesity was not associated with higher mortality in our cohort. Because our cohort is small, it may be underpowered to detect a smaller difference in outcome. From our observation, obesity should not be considered a contraindication for LT. Post-LT interventions are required to prevent significant weight gain for the class III obesity group.

Intestinal Gpr17 deficiency improves glucose metabolism by promoting GLP-1 secretion.

G protein-coupled receptors (GPCRs) in intestinal enteroendocrine cells (EECs) respond to nutritional, neural, and microbial cues and modulate the release of gut hormones. Here we show that Gpr17, an orphan GPCR, is co-expressed in glucagon-like peptide-1 (GLP-1)-expressing EECs in human and rodent intestinal epithelium. Acute genetic ablation of Gpr17 in intestinal epithelium improves glucose tolerance and glucose-stimulated insulin secretion (GSIS). Importantly, inducible knockout (iKO) mice and Gpr17 null intestinal organoids respond to glucose or lipid ingestion with increased secretion of GLP-1, but not the other incretin glucose-dependent insulinotropic polypeptide (GIP). In an in vitro EEC model, overexpression or agonism of Gpr17 reduces voltage-gated calcium currents and decreases cyclic AMP (cAMP) production, and these are two critical factors regulating GLP-1 secretion. Together, our work shows that intestinal Gpr17 signaling functions as an inhibitory pathway for GLP-1 secretion in EECs, suggesting intestinal GPR17 is a potential target for diabetes and obesity intervention.

Severe Alcohol-Associated Hepatitis Is Associated With Worse Survival in Critically Ill Patients With Acute on Chronic Liver Failure.

Differences in mortality between critically ill patients with severe alcohol-associated hepatitis (sAH) and acute-on-chronic liver failure (ACLF) and non-sAH ACLF (i.e., ACLF not precipitated by sAH) are unknown. Such differences are important, as they may inform on prognosis and optimal timing of liver transplantation (LT). Thus, we aimed to compare short-term and longer-term mortality between patients with sAH ACLF and patients with non-sAH ACLF who were admitted to the intensive care unit. Patients with ACLF admitted from 2016-2018 at two tertiary care intensive care units were analyzed. SAH was defined by the National Institute on Alcohol Abuse and Alcoholism's Alcoholic Hepatitis Consortium and Model for End-Stage Liver Disease score >20. Mortality without LT was compared between sAH ACLF and non-sAH ACLF using Fine and Gray's competing-risks regression. A total of 463 patients with ACLF (18% sAH and 82% non-sAH) were included. Compared to patients with non-sAH ACLF, patients with sAH ACLF were younger (49 vs. 56 years; P < 0.001) and had higher admission Model for End-Stage Liver Disease (MELD) (35 vs. 25; P < 0.001) and Chronic Liver Failure Consortium (CLIF-C) scores (61 vs. 57; P = 0.002). There were no significant differences between the two groups for vasopressor, mechanical ventilation, and hemodialysis use. The cumulative incidence of death was significantly higher in patients with sAH ACLF compared to patients with non-sAH ACLF: 30-day 74.7% versus 45.3%; 90-day 81.9% versus 57.4%; 180-day 83.2% versus 63.0% (unadjusted subdistribution hazard ratio [sHR] 1.88 [95% confidence interval (CI) 1.44-2.46]; P < 0.001). After adjusting for CLIF-C score and infection in a multivariable competing-risk model, patients with sAH ACLF had significantly higher risk of death (sHR 1.57 [95% CI 1.20-2.06]; P = 0.001) compared to patients with non-sAH ACLF. Conclusion: Critically ill patients with sAH ACLF have worse mortality compared to patients with non-sAH ACLF. These data may inform prognosis in patients with sAH and ACLF, and early LT referral in potentially eligible patients.

Impact of the acuity circle model for liver allocation on multivisceral transplant candidates.

Liver allocation was updated on February 4, 2020, replacing a Donor Service Area (DSA) with acuity circles (AC). The impact on waitlist outcomes for patients listed for combined liver-intestine transplantation (multivisceral transplantation [MVT]) remains unknown. The Organ Procurement and Transplantation Network/United Network for Organ Sharing database was used to identify all candidates listed for both liver and intestine between January 1, 2018 and March 5, 2021. Two eras were defined: pre-AC (2018-2020) and post-AC (2020-2021). Outcomes included 90-day waitlist mortality and transplant probability. A total of 127 adult and 104 pediatric MVT listings were identified. In adults, the 90-day waitlist mortality was not statistically significantly different, but transplant probability was lower post-AC. After risk-adjustment, post-AC was associated with a higher albeit not statistically significantly different mortality hazard (sub-distribution hazard ratio[sHR]: 8.45, 95% CI: 0.96-74.05; p = .054), but a significantly lower transplant probability (sHR: 0.33, 95% CI: 0.15-0.75; p = .008). For pediatric patients, waitlist mortality and transplant probability were similar between eras. The proportion of patients who underwent transplant with exception points was lower post-AC both in adult (44% to 9%; p = .04) and pediatric recipients (65% to 15%; p = .002). A lower transplant probability observed in adults listed for MVT may ultimately result in increased waitlist mortality. Efforts should be taken to ensure equitable organ allocation in this vulnerable patient population.

Human organ donor-derived vagus nerve biopsies allow for well-preserved ultrastructure and high-resolution mapping of myelinated and unmyelinated fibers.

The vagus nerve provides motor, sensory, and autonomic innervation of multiple organs, and electrical vagus nerve stimulation (VNS) provides an adjunctive treatment option for e.g. medication-refractory epilepsy and treatment-resistant depression. The mechanisms of action for VNS are not known, and high-resolution anatomical mapping of the human vagus nerve is needed to better understand its functional organization. Electron microscopy (EM) is required for the detection of both myelinated and unmyelinated axons, but access to well-preserved human vagus nerves for ultrastructural studies is sparse. Intact human vagus nerve samples were procured intra-operatively from deceased organ donors, and tissues were immediately immersion fixed and processed for EM. Ultrastructural studies of cervical and sub-diaphragmatic vagus nerve segments showed excellent preservation of the lamellated wall of myelin sheaths, and the axolemma of myelinated and unmyelinated fibers were intact. Microtubules, neurofilaments, and mitochondria were readily identified in the axoplasm, and the ultrastructural integrity of Schwann cell nuclei, Remak bundles, and basal lamina was also well preserved. Digital segmentation of myelinated and unmyelinated axons allowed for determination of fiber size and myelination. We propose a novel source of human vagus nerve tissues for detailed ultrastructural studies and mapping to support efforts to refine neuromodulation strategies, including VNS.

Optimal Timing of Administration of Direct-acting Antivirals for Patients With Hepatitis C-associated Hepatocellular Carcinoma Undergoing Liver Transplantation.

OBJECTIVE: To investigate the optimal timing of direct acting antiviral (DAA) administration in patients with hepatitis C-associated hepatocellular carcinoma (HCC) undergoing liver transplantation (LT). SUMMARY OF BACKGROUND DATA: In patients with hepatitis C (HCV) associated HCC undergoing LT, the optimal timing of direct-acting antivirals (DAA) administration to achieve sustained virologic response (SVR) and improved oncologic outcomes remains a topic of much debate. METHODS: The United States HCC LT Consortium (2015-2019) was reviewed for patients with primary HCV-associated HCC who underwent LT and received DAA therapy at 20 institutions. Primary outcomes were SVR and HCC recurrence-free survival (RFS). RESULTS: Of 857 patients, 725 were within Milan criteria. SVR was associated with improved 5-year RFS (92% vs 77%, P < 0.01). Patients who received DAAs pre-LT, 0-3 months post-LT, and ≥3 months post-LT had SVR rates of 91%, 92%, and 82%, and 5-year RFS of 93%, 94%, and 87%, respectively. Among 427 HCV treatment-naïve patients (no previous interferon therapy), patients who achieved SVR with DAAs had improved 5-year RFS (93% vs 76%, P < 0.01). Patients who received DAAs pre-LT, 0-3 months post-LT, and ≥3 months post-LT had SVR rates of 91%, 93%, and 78% (P < 0.01) and 5-year RFS of 93%, 100%, and 83% (P = 0.01). CONCLUSIONS: The optimal timing of DAA therapy appears to be 0 to 3 months after LT for HCV-associated HCC, given increased rates of SVR and improved RFS. Delayed administration after transplant should be avoided. A prospective randomized controlled trial is warranted to validate these results.