Enhancing pre-transplant cardiac assessment: Validation and utility of the CAD-LT score with CCTA in liver transplant candidates

BACKGROUND

Coronary computed tomography angiography (CCTA) is increasingly being used in the preoperative workup for liver transplantation (LT). We sought to assess the utility of integrating CCTA with the novel CAD-LT (Coronary Artery Disease in Liver Transplantation) score and its impact on reducing the need for invasive coronary angiography prior to LT.

METHODS

We conducted a retrospective cohort study of consecutive patients (age ≥ 18 years) who underwent CCTA for LT workup between 2011 and 2018 at the Victorian Liver Transplant Unit, Melbourne, Australia. CAD-LT scores, a traditional risk factor-based criteria, were calculated, and patients stratified as low-, intermediate- or high-risk.

RESULTS

Overall, 229 patients underwent CCTA. The mean age was 66 ± 5 years (82% male) with a modest-to-high risk factor burden (diabetes, 53%; hypertension, 46%; current or former smoker, 62%). The mean CAD-LT score of our cohort was 12.4 ± 4.0. No patients were classified as low-risk, 49 patients (21.4%) were deemed intermediate-risk and 180 patients (78.6%) were deemed high-risk. A high CAD-LT score (≥ 9) showed high sensitivity (95.3% [95% CI 86-98%]) and modest specificity (27.8% [95% CI 21-35%]) for the detection of obstructive coronary artery disease on CCTA, with a negative predictive value of 94%. Following multidisciplinary discussions, only 41 patients (18%) of patients proceeded to ICA of which 27% received percutaneous coronary intervention.

CONCLUSIONS

The use of CCTA in patients deemed intermediate- to high-risk by the CAD-LT score has the potential to reduce the need for invasive coronary angiography in patients undergoing LT workup.

The Health Care Burden of Hepatic Encephalopathy

Hepatic encephalopathy-a common and debilitating complication of cirrhosis-results in major health care burden on both patients and caregivers through direct and indirect costs. In addition to risk of falls, inability to work and drive, patients with hepatic encephalopathy often require hospital admission (and often readmission), and many require subacute care following hospitalization. The costs and psychological impact of liver transplantation often ensue. As the prevalence of chronic liver disease increases throughout the United States, the health care burden of hepatic encephalopathy will continue to grow.

Nontraditional Treatment of Hepatic Encephalopathy

The pathophysiology of hepatic encephalopathy (HE) is complex, with hyperammonemia playing a central role in its development. Traditional therapies for HE have targeted ammonia and include medications such as lactulose and rifaximin. Although these agents are considered standard of care, nontraditional treatments seek to affect other factors in the pathogenesis of HE. Finally, procedural therapies include albumin dialysis, shunt closure, and the ultimate cure for HE, which is liver transplant. The treatments discussed provide alternative options for patients who have failed standard of care. However, more high-quality studies are needed to routinely recommend many of these agents.

Evaluation of Induction Immunosuppression and Risk of Incisional Hernia After Liver Transplantation

INTRODUCTION

Liver transplantation (LT) is a technically complex operation and usually performed on ill patients. A major postoperative morbidity is incisional hernia, occurring in 9.5%-32.4% of cases. There are mixed results in transplant studies regarding potential risk factors. Additionally, the literature is lacking in the relationship between specific immunosuppressive induction agents administered during LT and postoperative incisional hernia.

METHODS

A single center, retrospective cohort study of patients who underwent primary LT between 4/2011-1/2018 was conducted. Clinical variables including demographics and comorbidities were reviewed. The primary end point was the development of an incisional hernia following LT. Sub analysis was performed for secondary end points to determine potential risk factors, including immunosuppressive induction agent.

RESULTS

Overall, 418 patients met inclusion criteria. At 5 y post-LT, there were 66/271 (24.4%) and 53/147 (36.1%) patients diagnosed with an incisional hernia in the methylprednisolone and basiliximab groups, respectively. After propensity score matching, there was no difference in incisional hernia development between induction agents, P = 0.19. For patients with body mass index ≥30 and postoperative seroma of the abdominal wall, the hazard ratios were 2.67 (95% CI = 1.7, 4.3) and 2.03 (95% CI = 1.1, 3.9), respectively.

CONCLUSIONS

Incisional hernia rate after LT was 28.5% at 5 y. Our analysis found that immunosuppressive induction agent at LT was not associated with the development of postoperative incisional hernia. However, preoperative obesity (body mass index ≥30) and postoperative seroma of the abdominal wall were potential risk factors. Further studies are needed to delineate if these risk factors remain across institutions and in alternative settings.

Liver Transplantation for Zellweger Syndrome

Zellweger syndrome or cerebrohepatorenal syndrome is a rare, multisystem disorder occurring due to defect in metabolic pathway within the peroxisomes. Cirrhosis with portal hypertension is an important presentation of these patients. Given its progressive, multisystem nature, the role of liver transplantation (LT) in Zellweger syndrome remains undefined and controversial. An 11-y-old boy diagnosed with Zellweger syndrome presented to the authors with decompensated cirrhosis along with bilateral proptosis. After a meticulous evaluation, he was offered an ABO incompatible liver transplantation with his mother being the donor. He had an uneventful post operative period. After a follow up of 24 mo, he has normal graft function, normal cognition along with resolution of proptosis. Therefore, in a group of carefully selected patients with Zellweger syndrome, a liver transplantation can be offered successfully with an excellent prognosis.

Liver Transplantation Reverses Hepatic Myelopathy in the Decompensated Phase of Cirrhosis: Case Report and Literature Review

Hepatic myelopathy (HM) is a rare neurological complication in the end stage of many liver diseases and is characterized by bilateral spastic paraparesis without sensory and sphincter dysfunction. It occurs owing to metabolic disorders and central nervous system dysfunction associated with cirrhosis. Without timely and effective clinical intervention, the prognosis of these patients is devastating. Although liver transplantation (LT) is an effective treatment for HM, the prognosis of these patients remains unsatisfactory. Early recognition and diagnosis of this disease are essential for improving patient prognosis. Here, we report a case of hepatitis B virus-associated decompensated cirrhosis with HM. The patient recovered well after LT. We also summarize the clinical characteristics and post-transplant outcomes of 25 patients with HM treated by LT through 2023, including this case.

Bulk and single-cell RNA sequencing analysis with 101 machine learning combinations reveal neutrophil extracellular trap involvement in hepatic ischemia-reperfusion injury and early allograft dysfunction

BACKGROUND

Hepatic ischaemia-reperfusion injury (HIRI) is a major clinical concern during the perioperative period and is closely associated with early allograft dysfunction (EAD), acute rejection (AR) and long-term graft survival. Neutrophil extracellular traps (NETs) are extracellular structures formed by the release of decondensed chromatin and granular proteins following neutrophil stimulation. There is growing evidence that NETs are involved in the progression of various liver transplantation complications, including ischaemia-reperfusion injury (IRI). This study aimed to comprehensively analyse the expression patterns of NET-related genes (NRGs) in HIRI, identify HIRI subtypes with distinct characteristics, and develop a reliable EAD prediction model.

METHODS

Microarray, bulk RNA-seq, and single-cell sequencing datasets were obtained from the GEO database. Initially, differentially expressed NRGs (DE-NRGs) were identified using differential gene expression analyses. We then utilised a non-negative matrix factorisation (NMF) algorithm to classify HIRI samples. Subsequently, we employed machine learning algorithms to screen the hub NRGs related to EAD and developed an EAD prediction model based on these hub NRGs. Concurrently, we assessed the expression patterns of hub NRGs at the single-cell level using the HIRI. Additionally, we validated C5AR1 expression and its effect on HIRI and NETs formation in a rat orthotopic liver transplantation (OLT) model.

RESULTS

In this study, we identified 11 DE-NRGs in the HIRI context. Based on these 11 DE-NRGs, HIRI samples were classified into two distinct clusters. Cluster1 exhibited a low expression of DE-NRGs, minimal neutrophil infiltration, mild inflammation, and a low incidence of EAD. Conversely, Cluster2 displayed the opposite phenotype, with an activated inflammatory subtype and a higher incidence of EAD. Furthermore, an EAD prediction model was developed using the four hub NRGs associated with EAD. Based on risk scores, HIRI samples were classified into high- and low-risk groups. The OLT model confirmed substantial upregulation of C5AR1 expression in the liver tissue, accompanied by increased formation of NETs. Treatment with a C5AR1 antagonist improved liver function, reduced tissue inflammation, and decreased NETs formation.

CONCLUSIONS

This study distinguished two apparent HIRI subtypes, established a predictive model for EAD, and validated the effect of C5AR1 on HIRI. These findings provide novel perspectives for the development of advanced clinical strategies to enhance the outcomes of liver transplant recipients.

Risk factors and prediction score for new-onset diabetes mellitus after liver transplantation

AIM

New-onset diabetes mellitus is a frequent and severe complication arising after liver transplantation (LT). We aimed to identify the risk factors for new-onset diabetes mellitus after liver transplantation (NODALT) and to develop a risk prediction score system for relevant risks.

METHODS

We collected and analyzed data from all recipients who underwent liver transplantation at the First Affiliated Hospital of Xi'an Jiaotong University. The OR derived from a multiple logistic regression predicting the presence of NODALT was used to calculate the risk prediction score. The performance of the risk prediction score was externally validated in patients who were from the CLTR (China Liver Transplant Registry) database.

RESULTS

A total of 468 patients met the outlined criteria and finished the follow-up. Overall, NODALT was diagnosed in 115 (24.6%) patients. Age, preoperative impaired fasting glucose (IFG), postoperative fasting plasma glucose (FPG), and the length of hospital stay were significantly associated with the presence of NODALT. The risk prediction score includes age, preoperative IFG, postoperative FPG, and the length of hospital stay. The risk prediction score of the area under the receiver operating curve was 0.785 (95% CI: 0.724-0.846) in the experimental population and 0.782 (95% CI: 0.708-0.856) in the validation population.

CONCLUSIONS

Age at the time of transplantation, preoperative IFG, postoperative FPG, and length of hospital stay were independent predictive factors of NODALT. The use of a simple risk prediction score can identify the patients who have the highest risk of NODALT and interventions may start early.

NR1H4 disease: rapidly progressing neonatal intrahepatic cholestasis and early death

BACKGROUND

Clinical studies on progressive familial intrahepatic cholestasis (PFIC) type 5 caused by mutations in NR1H4 are limited.

METHODS

New patients with biallelic NR1H4 variants from our center and all patients from literature were retrospectively analyzed.

RESULTS

Three new patients were identified to be carrying five new variants. Liver phenotypes of our patients manifests as low-γ-glutamyl transferase cholestasis, liver failure and related complications. One patient underwent liver transplantation (LT) and survived, and two other patients died without LT. Nine other patients were collected through literature review. Twelve out of 13 patients showed neonatal jaundice, with the median age of onset being 7 days after birth. Reported clinical manifestations included cholestasis (13/13, 100%), elevated AFP (11/11, 100%), coagulopathy (11/11, 100%), hypoglycemia (9/13, 69%), failure to thrive (8/13, 62%), splenomegaly (7/13, 54%), hyperammonemia (7/13, 54%), and hepatomegaly (6/13, 46%). Six of 13 patients received LT at a median age of 6.2 months, and only one patient died of acute infection at one year after LT. Other 7 patients had no LT and died with a median age of 5 months (range 1.2-8). There were 8 patients with homozygous genotype and 5 patients with compound heterozygous genotype. In total, 13 different variants were detected, and 5 out of 12 single or multiple nucleotides variants were located in exon 5.

CONCLUSIONS

We identified three newly-diagnosed patients and five novel mutations. NR1H4-related PFIC typically cause progressive disease and early death. LT may be the only lifesaving therapy leading to cure.

Automated liver volumetry and hepatic steatosis quantification with magnetic resonance imaging proton density fat fraction

BACKGROUND

Preoperative imaging evaluation of liver volume and hepatic steatosis for the donor affects transplantation outcomes. However, computed tomography (CT) for liver volumetry and magnetic resonance spectroscopy (MRS) for hepatic steatosis are time consuming. Therefore, we investigated the correlation of automated 3D-multi-echo-Dixon sequence magnetic resonance imaging (ME-Dixon MRI) and its derived proton density fat fraction (MRI-PDFF) with CT liver volumetry and MRS hepatic steatosis measurements in living liver donors.

METHODS

This retrospective cross-sectional study was conducted from December 2017 to November 2022. We enrolled donors who received a dynamic CT scan and an MRI exam within 2 days. First, the CT volumetry was processed semiautomatically using commercial software, and ME-Dixon MRI volumetry was automatically measured using an embedded sequence. Next, the signal intensity of MRI-PDFF volumetric data was correlated with MRS as the gold standard.

RESULTS

We included the 165 living donors. The total liver volume of ME-Dixon MRI was significantly correlated with CT (r = 0.913, p < 0.001). The fat percentage measured using MRI-PDFF revealed a strong correlation between automatic segmental volume and MRS (r = 0.705, p < 0.001). Furthermore, the hepatic steatosis group (MRS ≥5%) had a strong correlation than the non-hepatic steatosis group (MRS <5%) in both volumetric (r = 0.906 vs. r = 0.887) and fat fraction analysis (r = 0.779 vs. r = 0.338).

CONCLUSION

Automated ME-Dixon MRI liver volumetry and MRI-PDFF were strongly correlated with CT liver volumetry and MRS hepatic steatosis measurements, especially in donors with hepatic steatosis.

New insights into the regulation of bile acids synthesis during the early stages of liver regeneration: A human and experimental study

BACKGROUND AND AIMS

Liver regeneration is essential for the preservation of homeostasis and survival. Bile acids (BAs)-mediated signaling is necessary for liver regeneration, but BAs levels need to be carefully controlled to avoid hepatotoxicity. We studied the early response of the BAs-fibroblast growth factor 19 (FGF19) axis in healthy individuals undergoing hepatectomy for living donor liver transplant. We also evaluated BAs synthesis in mice upon partial hepatectomy (PH) and acute inflammation, focusing on the regulation of cytochrome-7A1 (CYP7A1), a key enzyme in BAs synthesis from cholesterol.

METHODS

Serum was obtained from twelve human liver donors. Mice underwent 2/3-PH or sham-operation. Acute inflammation was induced with bacterial lipopolysaccharide (LPS) in mice fed control or antoxidant-supplemented diets. BAs and 7α-hydroxy-4-cholesten-3-one (C4) levels were measured by HPLC-MS/MS; serum FGF19 by ELISA. Gene expression and protein levels were analyzed by RT-qPCR and western-blot.

RESULTS

Serum BAs levels increased after PH. In patients with more pronounced hypercholanemia, FGF19 concentrations transiently rose, while C4 levels (a readout of CYP7A1 activity) dropped 2 h post-resection in all cases. Serum BAs and C4 followed the same pattern in mice 1 h after PH, but C4 levels also dropped in sham-operated and LPS-treated animals, without marked changes in CYP7A1 protein levels. LPS-induced serum C4 decline was attenuated in mice fed an antioxidant-supplemented diet.

CONCLUSIONS

In human liver regeneration FGF19 upregulation may constitute a protective response from BAs excess during liver regeneration. Our findings suggest the existence of post-translational mechanisms regulating CYP7A1 activity, and therefore BAs synthesis, independent from CYP7A1/Cyp7a1 gene transcription.

Antiplatelet agent for the prevention of late hepatic vascular complications in living donor liver transplant dominant population

BACKGROUND

Evidence for the long-term use of antiplatelet drugs to prevent hepatic vascular complications (HVC) is scarce in liver transplantation (LT).

METHODS

From national claim data, LT recipients (about 80 % of living donor LT [LDLT]) without graft loss, HVC, or cardiovascular events within 1 year, were classified into those who took antiplatelets for ≥1 year (n = 1744) and for <1 year (n = 1975). Outcomes were compared after the 1-postoperative year index time point.

RESULTS

During a mean follow up of 4.5 years, the risk of graft loss was similar between the groups (aHR 1.16, P = 0.23). However, ≥1-year antiplatelet therapy was associated with a higher risk of graft loss after 3 years (aHR 2.19, P < 0.01). HVC (aHR 0.94, P = 0.87) and major adverse cardiac events (aHR 1.20, P = 0.46) did not correlate with antiplatelet therapy for both groups. In contrast, ≥1-year antiplatelet therapy showed a significantly higher risk of severe bleeding compared to <1-year antiplatelet therapy (aHR 2.24, P < 0.01). This trend was similar in the LDLT subgroup. In our cohort, antiplatelet therapy for ≥1 year did not improve graft survival or HVC; however, it increased the risk of severe bleeding.

CONCLUSION

We recommend against antiplatelet therapy for more than 1 year in clinically stable LT recipients.

Current status of liver transplantation for human immunodeficiency virus-infected patients in mainland China

According to the report from the Chinese Center for Disease Control and Prevention, the prevalence of human immunodeficiency virus (HIV) infection exceeded 1.2 million individuals by the year 2022, with an annual increase of about 80000 cases. The overall prevalence of hepatitis B surface antigen among individuals co-infected with HIV reached 13.7%, almost twice the rate of the general population in China. In addition to the well-documented susceptibility to opportunistic infections and new malignancies, HIV infected patients frequently experience liver-related organ damage, with the liver and kidneys being the most commonly affected. This often leads to the development of end-stage liver and kidney diseases. Therefore, organ transplantation has emerged as an important part of active treatment for HIV infected patients. However, the curative effect is not satisfactory. HIV infection has been considered a contraindication for organ transplantation. Until the emergence of highly active anti-retroviral therapy in 1996, the once intractable replication of retrovirus was effectively inhibited. With prolonged survival, the failure of important organs has become the main cause of death among HIV patients. Therefore, transplant centers worldwide have resumed exploration of organ transplantation for HIV-infected individuals and reached a positive conclusion. This study provides an overview of the current landscape of HIV-positive patients receiving liver transplantation (LT) in mainland China. To date, our transplant center has conducted LT for eight end-stage liver disease patients co-infected with HIV, and all but one, who died two months postoperatively due to sepsis and progressive multi-organ failure, have survived. Comparative analysis with hepatitis B virus-infected patients during the same period revealed no statistically significant differences in acute rejection reactions, cytomegalovirus infection, bacteremia, pulmonary infections, acute kidney injury, new-onset cancers, or vascular and biliary complications.

Activation of farnesoid X receptor enhances the efficacy of normothermic machine perfusion in ameliorating liver ischemia-reperfusion injury

BACKGROUND

The shortage of transplant organs remains a severe global issue. Normothermic machine perfusion (NMP) has the potential to increase organ availability, yet its efficacy is hampered by the inflammatory response during machine perfusion.

METHODS

Mouse liver IRI models, discarded human liver models, and porcine marginal liver transplantation models were utilized to investigate whether FXR activation could mitigate inflammation-induced liver damage. FXR expression levels before and after reperfusion were measured. Gene editing and co-immunoprecipitation techniques were employed to explore the regulatory mechanism of FXR in inflammation inhibition.

RESULTS

The expression of FXR correlates with the extent of liver damage after reperfusion. Activation of FXR significantly suppressed the inflammatory response triggered by IRI, diminished the release of pro-inflammatory cytokines, and improve liver function recovery during NMP, assisting discarded human livers to reach transplant standards. Mechanistically, FXR disrupts the interaction between p65 and p300, thus inhibiting modulating the nuclear factor kappa-B (NF-κB) signaling pathway, a key instigator of inflammation.

CONCLUSION

Our research across multiple species confirms that activating FXR can optimize NMP by attenuating IRI-related liver damage, thereby improving the utilization of marginal livers for transplantation.

Coronary artery calcium assessment on non-gated chest CT to optimize pre-operative cardiac screening in liver transplantation

BACKGROUND

Guidelines recommend standard pre-operative cardiac screening in all liver transplantation (LT) recipients, despite the relatively low prevalence of obstructive coronary artery disease. Most LT recipients often have non-gated computed tomography (CT) performed of the chest and abdomen. This study evaluated the ability of coronary artery calcification (CAC) assessment on consecutively available scans, to identify a selection of low-risk patients, in whom further cardiac imaging can be safely withheld.

METHODS

LT recipients with prior non-gated CT chest-abdomen were included. CAC was visually scored on a semi-quantitative ordinal scale. Stress myocardial perfusion, coronary CT angiography (CCTA) and invasive coronary angiography (ICA) were used as golden standard. The sensitivity and specificity of CAC to exclude and predict obstructive CAD were assessed. In addition, peri- and postoperative mortality and cardiac events were analyzed.

RESULTS

149 LT recipients (ranged 31-71 years) were included. In 75% of patients, no CAC and mild CAC could rule out obstructive CAD on CCTA and ICA with 100% certainty. The threshold of mild CAC had a sensitivity of 100% for both CCTA and ICA and a specificity of 91% and 68%, respectively. None of the patients with no or mild calcifications experienced peri- and post-operative cardiac events or died of cardiac causes.

CONCLUSION

Visual evaluation of CAC on prior non-gated CT can accurately and safely exclude obstructive CAD in LT recipients. Incorporation of these already available data can optimize cardiac screening, by safely withholding or correctly allocating dedicated cardiac imaging in LT recipients. Thereby, reducing patients' test burden and save health care expenses.

Clinical outcomes of liver transplantation in human immunodeficiency virus/hepatitis B virus coinfected patients in China

BACKGROUND

Highly active antiretroviral therapy (HAART) has been able to improve the immune system function and survival of human immunodeficiency virus (HIV) patients. However, Patients coinfected with HIV and hepatitis B virus (HBV) are more likely to develop end-stage liver disease (ESLD) than those infected with HBV alone. Consequently, liver transplantation is often required for these patients. This study evaluates the outcomes of orthotopic liver transplantation (OLT) of HIV-HBV coinfected patients in China.

METHODS

We conducted a retrospective analysis on all HIV-HBV coinfected patients that underwent OLT from April 1, 2019 to December 31, 2021 and their outcomes were compared to all HBV monoinfected patients undergoing OLT during the same period. Patient outcomes were determined, including cumulative survival, viral load, CD4 T-cell count and postoperative complications.

RESULTS

The median follow-up of HIV recipients was 36 months after OLT (interquartile range 12-39 months). Almost all patients had stable CD4 T-cell count (> 200 copies/ul), undetectable HBV DNA levels, and undetectable HIV RNA load during follow-up. The 1-, 2-, and 3-year posttransplant survival rates were 85.7% for the HIV group (unchanged from 1 to 3 years) versus 82.2%, 81.2%, and 78.8% for the non-HIV group. Cumulative survival among HIV-HBV coinfected recipients was not significantly different from the HBV monoinfected recipients (log-rank test P = 0.692). The percentage of deaths attributed to infection was comparable between the HIV and non-HIV groups (14.3% vs. 9.32%, P = 0.665). Post OLT, there was no significant difference in acute rejection, cytomegalovirus infection, bacteremia, pulmonary infection, acute kidney injury, de novo tumor and vascular and biliary complications.

CONCLUSIONS

Liver transplantation in patients with HIV-HBV coinfection yields excellent outcomes in terms of intermediate- or long-term survival rate and low incidence of postoperative complications in China. These findings suggest that OLT is safe and feasible for HIV-HBV coinfected patients with ESLD.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR2300067631), registered 11 January 2023.

Cellular strategies to induce immune tolerance after liver transplantation: Clinical perspectives

Liver transplantation (LT) has become the most efficient treatment for pediatric and adult end-stage liver disease and the survival time after transplantation is becoming longer due to the development of surgical techniques and perioperative management. However, long-term side-effects of immunosuppressants, like infection, metabolic disorders and malignant tumor are gaining more attention. Immune tolerance is the status in which LT recipients no longer need to take any immunosuppressants, but the liver function and intrahepatic histology maintain normal. The approaches to achieve immune tolerance after transplantation include spontaneous, operational and induced tolerance. The first two means require no specific intervention but withdrawing immunosuppressant gradually during follow-up. No clinical factors or biomarkers so far could accurately predict who are suitable for immunosuppressant withdraw after transplantation. With the understanding to the underlying mechanisms of immune tolerance, many strategies have been developed to induce tolerance in LT recipients. Cellular strategy is one of the most promising methods for immune tolerance induction, including chimerism induced by hematopoietic stem cells and adoptive transfer of regulatory immune cells. The safety and efficacy of various cell products have been evaluated by prospective preclinical and clinical trials, while obstacles still exist before translating into clinical practice. Here, we will summarize the latest perspectives and concerns on the clinical application of cellular strategies in LT recipients.

Diet and physical activity interventions to improve cardiovascular disease risk factors in liver transplant recipients: Systematic review and meta-analysis

BACKGROUND AND AIMS

Cardiovascular disease, associated risk factors and obesity are prevalent after liver transplant and modifiable through lifestyle changes. Understanding what lifestyle interventions and their respective components are effective is essential for translation to clinical practice. We aimed to investigate the effects of diet and physical activity interventions on weight, body mass index and other cardiovascular disease risk factors in liver transplant recipients, and systematically describe the interventions.

METHODS

We systematically searched Embase, MEDLINE, Psycho Info, CINAHL, Cochrane central register of controlled trials, PeDro, AMED, BNI, Web of Science, OpenGrey, ClinicalTrials.gov and the international clinical trials registry from inception to 31 May 2023. Search results were screened by two independent reviewers: randomised control trials with interventions that targeted diet and physical activity behaviours in liver transplant recipients were considered eligible. Two independent reviewers extracted and synthesised data for study, participant and intervention details and results. We used the Revised Cochrane Risk of Bias Tool for Randomised Trials to assess risk of bias for outcomes and the GRADE approach to rate the quality of the body of evidence. When two or more studies reported findings for an outcome, we pooled data using random-effects meta-analysis.

RESULTS

Six studies were included, reporting three physical activity and three combined diet and physical activity interventions. Participants were 2 months-4 years post-transplant. Interventions lasted 12 weeks-10 months and were delivered remotely and/or in-person, most commonly delivered to individual participants by health care or sports professionals. Five studies described individual tailoring, e.g. exercise intensity. Adherence to interventions ranged from 51% to 94%. No studies reported fidelity. Intervention components were not consistently reported. In meta-analysis, diet and physical activity interventions did not significantly reduce weight or body mass index compared to control groups, however no studies targeted participants with obesity. Diet and physical activity interventions reduced percentage body fat and triglycerides compared to control groups but did not reduce total cholesterol or increase activity. The GRADE quality of evidence was low or very low.

CONCLUSION

Diet and physical activity interventions reduced percentage body fat and triglycerides in liver transplant recipients. Further good quality research is needed to evaluate their effect on other cardiovascular disease risk factors, including weight and BMI. Interventions need to be better described and evaluated to improve evidence base and inform patient care.

Direct-Acting Antiviral Therapy for Patients with Chronic Hepatitis C Infection and Decompensated Cirrhosis

Patients with chronic hepatitis C virus (HCV) infection and decompensated cirrhosis are an important population for antiviral therapy yet under-represented in clinical trials. HCV direct-acting antiviral (DAA) therapies, unlike interferon-containing regimens, can be safely utilized in decompensated patients. Per guidelines from the American Association for the Study of Liver Diseases (AASLD), therapy of choice in HCV and decompensated cirrhosis is sofosbuvir, an HCV polymerase inhibitor, combined with a replication complex inhibitor (NS5A inhibitor) with or without ribavirin. Combination therapy with a HCV protease inhibitor and an NS5A inhibitor is effective in this population but is specifically not recommended in AASLD guidelines due to safety concerns. Important risk factors for further decompensation during DAA therapy are serum albumin < 3.5 g/dL, MELD (Model for End-Stage Liver Disease) score > 14, or HCV genotype 3 infection. Although sustained virologic response (SVR) is achieved less often in patients with decompensated vs compensated cirrhosis, in clinical studies response rates are > 80%. Both Child-Turcotte-Pugh Class at baseline and viral genotype can affect these response rates. Achieving SVR lowers risk of mortality, but to a lesser extent than in individuals with compensated cirrhosis. Likewise, treating patients for HCV infection along with successful treatment for hepatocellular carcinoma improves risks of both liver-related and overall mortality. In fewer than one third of cases, treating transplant-eligible, HCV-infected patients pre-transplant enables their delisting from transplant wait lists.

Return of the cold: How hypothermic oxygenated machine perfusion is changing liver transplantation

Hypothermic Oxygenated machine PErfusion (HOPE) has recently emerged as a preservation technique which can reduce ischemic injury and improve clinical outcomes following liver transplantation. First developed with the advent solid organ transplantation techniques, hypothermic machine perfusion largely fell out of favour following the development of preservation solutions which can satisfactorily preserve grafts using the cheap and simple method, static cold storage (SCS). However, with an increasing need to develop techniques to reduce graft injury and better utilise marginal and donation after circulatory death (DCD) grafts, HOPE has emerged as a relatively simple and safe technique to optimise clinical outcomes following liver transplantation. Perfusing the graft with cold, acellular, oxygenated perfusate either via the portal vein (PV) alone, or via both the PV and hepatic artery (HA), HOPE is generally commenced for a period of 1-2 h immediately prior to implantation. The technique has been validated by multiple randomised control trials, and pre-clinical evidence suggests HOPE primarily reduces graft injury by decreasing the accumulation of harmful mitochondrial intermediates, and subsequently, the severity of post-reperfusion injury. HOPE can also facilitate real time graft assessment, most notably via the measurement of flavin mononucleotide (FMN) in the perfusate, allowing transplant teams to make better informed clinical decisions prior to transplantation. HOPE may also provide a platform to administer novel therapeutic agents to ex situ organs without risk of systemic side effects. As such, HOPE is uniquely positioned to revolutionise how liver transplantation is approached and facilitate optimised clinical outcomes for liver transplant recipients.

Liver transplantation as an alternative for the treatment of non-resectable liver colorectal cancer: Advancing the therapeutic algorithm

Colorectal cancer is a leading cause of cancer-related mortality, with nearly half of the affected patients developing liver metastases. For three decades, liver resection (LR) has been the primary curative strategy, yet its applicability is limited to about 20% of cases. Liver transplantation (LT) for unresectable metastases was attempted unsuccessfully in the 1990s, with high rates of perioperative death and recurrence. There is now more interest in this strategy due to improvements in systemic therapies and surgical techniques. A significant study conducted by the Oslo group showed that patients receiving liver transplants had a 60% chance of survival after five years. Significantly better results have been achieved by using advanced imaging for risk stratification and further refining selection criteria, especially in the Norvegian SECA trials. This review carefully charts the development and history of LT as a treatment option for colorectal cancer liver metastases. The revolutionary path from the early days of exploratory surgery to the current situation of cautious optimism is traced, highlighting the critical clinical developments and improved patient selection standards that have made LT a potentially curative treatment for such challenging very well selected cases.

Nutrition in Pediatric Liver Disease

In liver disease, there is derangement of appetite, digestion, absorption, assimilation, storage and metabolism of both macro and micronutrients. These derangements have an impact on mortality and morbidity associated with liver diseases. In infants, breast feeds should not be stopped unless there are compelling reasons such as underlying metabolic problem. Parenteral nutrition should be considered only if, oral or nasogastric feeding is not possible. The effect of malnutrition on liver disease and impact of liver failure on nutrition is vicious and nutritional intervention has to be done at the earliest to break that vicious cycle. This chapter gives an overview of nutritional management in acute and chronic liver diseases in children and also its impact on specific clinical scenarios including liver transplantation.

Cirrhotic cardiomyopathy: Pathogenesis, clinical features, diagnosis, treatment and prognosis

Cardiac dysfunction among cirrhotic patients has long been recognized in the medical community. While it was originally believed to be a direct result of alcohol toxicity, in the last 30 years cirrhotic cardiomyopathy (CCM) has been described as a syndrome characterized by chronic cardiac dysfunction in cirrhotic patients in the absence of known cardiac disease, regardless of the etiology of cirrhosis. CCM occurs in about 60% of patients with cirrhosis and plays a critical role in disease progression and treatment outcomes. Due to its predominantly asymptomatic course, diagnosing CCM is challenging and requires a high index of suspicion and a multiparametric approach. Patients with CCM usually present with the following triad: impaired myocardial contractile response to exercise, inadequate ventricular relaxation, and electrophysiological abnormalities (notably prolonged QT interval). In recent years, research in this area has grown expeditiously and a new set of diagnostic criteria has been developed by the Cirrhotic Cardiomyopathy Consortium, to properly identify patients with CCM. Nevertheless, CCM is still largely unknown among clinicians, and a major part of its pathophysiology and treatment is yet to be understood. In the present work, we aim to compile and summarize the available data on the pathogenesis, clinical features, diagnosis, treatment, and prognosis of CCM.

Sleeve Gastrectomy Reduces the Need for Liver Transplantation in Patients with Obesity and Non-Alcoholic Steatohepatitis: a Predictive Model

BACKGROUND

Non-alcoholic steatohepatitis (NASH) is one of the leading indications for liver transplantation (LT) in the United States. As with the current obesity epidemic, the incidence of NASH continues to rise. However, the impact of broad utilization of bariatric surgery (BS) for patients with NASH is unknown, particularly in regard to mitigating the need for LT.

METHODS

Markov decision analysis was performed to simulate the lives of 20,000 patients with obesity and concomitant NASH who were deemed ineligible to be waitlisted for LT unless they achieved a body mass index (BMI) < 35 kg/m2. Life expectancy following medical weight management (MWM) and sleeve gastrectomy (SG) were estimated. Base case patients were defined as having NASH without fibrosis and a pre-intervention BMI of 45 kg/m2. Sensitivity analysis of initial BMI was performed.

RESULTS

Simulated base case analysis patients who underwent SG gained 14.3 years of life compared to patients who underwent MWM. One year after weight loss intervention, 9% of simulated MWM patients required LT compared to only 5% of SG patients. Survival benefit for SG was observed above a BMI of 32.2 kg/m2.

CONCLUSION

In this predictive model of 20,000 patients with obesity and concomitant NASH, surgical weight loss is associated with a reduction in the progression of NASH, thereby reducing the need for LT. A reduced BMI threshold of 32 kg/m2 for BS may offer survival benefit for patients with obesity and NASH.

Liver transplantation as an alternative for the treatment of perihilar cholangiocarcinoma: A critical review

BACKGROUND

Perihilar cholangiocarcinoma (phCCC) is a dismal malignancy. There is no consensus regarding the best treatment for patients with unresectable phCCC. The present review aimed to gather the current pieces of evidence for liver transplantation and liver resection as a treatment for phCCC and to build better guidance for clinical practice.

DATA SOURCES

The search was conducted in PubMed, Embase, Cochrane, and LILACS. The related references were searched manually. Inclusion criteria were: reports in English or Portuguese literature that a) patients with confirmed diagnosis of phCCC; b) patients treated with a curative intent; c) patients with the outcomes of liver resection and liver transplantation. Case reports, reviews, letters, editorials, conference abstracts and papers with full-text unavailability were excluded from the analysis.

RESULTS

Most of the current literature is based on observational retrospective studies with low grades of evidence. Liver resection has better long-term outcomes than systemic chemotherapy or palliation therapy and liver transplantation is a good alternative for selected patients with unresectable phCCC. All candidates for resection or transplantation should be medically fit and free of intrahepatic or extrahepatic diseases. As a general rule, patients presenting with a tumor having a longitudinal size > 3 cm or extending below the cystic duct, lymph node disease, confirmed extrahepatic dissemination; intraoperatively diagnosed metastatic disease; a history of other malignancies within the last five years, and did not complete chemoradiation regimen and were medically unfit should not be considered for transplantation. Some of these criteria should be individually assessed. Liver transplantation or resection should only be considered in highly experienced hepatobiliary centers, and any decision-making must be based on a multidisciplinary evaluation.

CONCLUSIONS

phCCC is a complex condition with high morbidity. Surgical therapies, including hepatectomy and liver transplantation, are the best option for better long-term disease-free survival.

Prehabilitation in patients awaiting liver transplantation

BACKGROUND

Frailty, malnutrition and sarcopenia lead to a significant increase in morbidity and mortality before and after liver transplantation (LT). Prehabilitation attempts to optimize physical fitness of individuals before major surgeries. To date, little is known about its impact on patients awaiting LT.

AIMS

The aim of our scoping review was to describe whether prehabilitation in patients awaiting LT is feasible and safe, and whether it leads to a change in clinical parameters before or after transplantation.

METHODS

We performed a systematic review of the literature from 1946 to November 2023 to identify prospective studies and randomized controlled trials of adult LT candidates who participated in an exercise training program.

RESULTS

Out of 3262 citations initially identified, six studies were included. Studies were heterogeneous in design, patient selection, intervention, duration, and outcomes assessed. All studies were self-described as pilot or feasibility studies and had a sample size ranging from 13 to 33. Two studies were randomized controlled trials. Two study restricted to patients with cirrhosis who were eligible for liver transplantation or on the transplant list. Exercise programs lasted between 6 and 12 weeks. In terms of feasibility, proportion of eligible patients that were recruited was between 54 and 100%. Program completion ranged between 38 and 90%. Interventions appeared safe with 9 (9.2%) adverse events noted. In the intervention group, improvements were generally noted in peak oxygen consumption and workload, 6-min walking distance, and muscle strength. One study suggested a decrease in post-transplant hospital length of stay.

CONCLUSIONS

Overall, it appears that prehabilitation with exercise training is feasible, and safe in patients awaiting LT. Higher quality and larger studies are needed to confirm its impact on pre- and post-transplantation-related outcomes.

Severity-adjusted evaluation of liver transplantation on health outcomes in urea cycle disorders

PURPOSE

Liver transplantation (LTx) is performed in individuals with urea cycle disorders when medical management (MM) insufficiently prevents the occurrence of hyperammonemic events. However, there is a paucity of systematic analyses on the effects of LTx on health-related outcome parameters compared to individuals with comparable severity who are medically managed.

METHODS

We investigated the effects of LTx and MM on validated health-related outcome parameters, including the metabolic disease course, linear growth, and neurocognitive outcomes. Individuals were stratified into "severe" and "attenuated" categories based on the genotype-specific and validated in vitro enzyme activity.

RESULTS

LTx enabled metabolic stability by prevention of further hyperammonemic events after transplantation and was associated with a more favorable growth outcome compared with individuals remaining under MM. However, neurocognitive outcome in individuals with LTx did not differ from the medically managed counterparts as reflected by the frequency of motor abnormality and cognitive standard deviation score at last observation.

CONCLUSION

Whereas LTx enabled metabolic stability without further need of protein restriction or nitrogen-scavenging therapy and was associated with a more favorable growth outcome, LTx-as currently performed-was not associated with improved neurocognitive outcomes compared with long-term MM in the investigated urea cycle disorders.

The wedish initiative for the stdy of ary sclerosing cholangitis (SUPRIM)

Background

Despite more than 50 years of research and parallel improvements in hepatology and oncology, there is still today neither a treatment to prevent disease progression in primary sclerosing cholangitis (PSC), nor reliable early diagnostic tools for the associated hepatobiliary cancers. Importantly, the limited understanding of the underlying biological mechanisms in PSC and its natural history not only affects the identification of new drug targets but implies a lack of surrogate markers that hampers the design of clinical trials and the evaluation of drug efficacy. The lack of easy access to large representative well-characterised prospective resources is an important contributing factor to the current situation.

Methods

We here present the SUPRIM cohort, a national multicentre prospective longitudinal study of unselected PSC patients capturing the representative diversity of PSC phenotypes. We describe the 10-year effort of inclusion and follow-up, an intermediate analysis report including original results, and the associated research resource. All included patients gave written informed consent (recruitment: November 2011-April 2016).

Findings

Out of 512 included patients, 452 patients completed the five-year follow-up without endpoint outcomes. Liver transplantation was performed in 54 patients (10%) and hepatobiliary malignancy was diagnosed in 15 patients (3%). We draw a comprehensive landscape of the multidimensional clinical and biological heterogeneity of PSC illustrating the diversity of PSC phenotypes. Performances of available predictive scores are compared and perspectives on the continuation of the SUPRIM cohort are provided.

Interpretation

We envision the SUPRIM cohort as an open-access collaborative resource to accelerate the generation of new knowledge and independent validations of promising ones with the aim to uncover reliable diagnostics, prognostic tools, surrogate markers, and new treatment targets by 2040.

Funding

This work was supported by the Swedish Cancer Society, Stockholm County Council, and the Cancer Research Funds of Radiumhemmet.

Epithelioid Hemangioendothelioma in a Liver Transplant Recipient: A Case Report of an Extremely Rare Tumor

Epithelioid hemangioendothelioma is a very rare vascular neoplasm, which is often multifocal or metastatic at diagnosis. Most frequently arises in the liver, followed by the lung and bones. The authors present a case of a liver transplant recipient who developed a pattern of hepatic cholestasis associated with the appearance of a proliferative hepatic lesion with infiltrative growth. Histological examination and immunohistochemical study were compatible with the diagnosis of epithelioid hemangioendothelioma. Pulmonary micronodules were detected and lung metastases were hypothesized. Therefore, bronchoscopy was performed, which turned out to be normal, and cytology was negative for neoplastic cells. After a multidisciplinary discussion, liver re-transplantation was decided. After 8 years of follow-up, the patient is clinically stable, with no graft dysfunction, no neoplastic recurrence, and dimensional stability of the pulmonary micronodules. Patients with organ transplant have higher risk of developing carcinoma compared to the general population. The development of cancer is a multifactorial process and little is known about the etiology of epithelioid hemangioendothelioma. No standard treatment strategy has been defined yet, and the natural course of the disease is heterogenous and the individual prognosis unpredictable. Complete surgical resection is offered to patients with unifocal disease, and those with unresectable disease should be evaluated for orthotopic liver transplantation.

Research progress on anatomy reconstruction of rat orthotopic liver transplantation

Rat orthotopic liver transplantation (ROLT) serves as an ideal animal model and has gained popularity in addressing complications and perioperative treatments related to clinical liver transplantation. Through extensive research on ROLT model construction, the conventional "two-cuff" method has gradually become established. However, traditional methods still present challenges including limited visual field during vascular suturing, vascular torsion, biliary tract injuries, and prolonged anhepatic periods. Consequently, this paper aims to review the latest advancements and various techniques in this field, providing a valuable reference for individuals interested in constructing ROLT models.

Exosomes derived from bone marrow mesenchymal stem cells alleviate biliary ischemia reperfusion injury in fatty liver transplantation by inhibiting ferroptosis

Fatty liver grafts are susceptible to ischemia reperfusion injury (IRI), increasing the risk of biliary complications after liver transplantation (LT). Ferroptosis, a newly recognized programmed cell death, is expected to be a novel therapeutic target for IRI. We investigated whether exosomes derived from heme oxygenase 1-modified bone marrow mesenchymal stem cells (HExos) relieve ferroptosis and protect biliary tracts from IRI in a rat fatty liver transplantation model. Rats were fed with a methionine choline deficient (MCD) diet for 2 weeks to induce severe hepatic steatosis. Steatotic grafts were implanted and HExos were administered after liver transplantation. A series of functional assays and pathological analysis were performed to assess ferroptosis and biliary IRI. The HExos attenuated IRI following liver transplantation, as demonstrated by less ferroptosis, improved liver function, less Kupffer and T cell activation, and less long-term biliary fibrosis. MicroRNA (miR)-204-5p delivered by HExos negatively regulated ferroptosis by targeting a key pro-ferroptosis enzyme, ACSL4. Ferroptosis contributes to biliary IRI in fatty liver transplantation. HExos protect steatotic grafts by inhibiting ferroptosis, and may become a promising strategy to prevent biliary IRI and expand the donor pool.

miRNA as potential biomarkers after liver transplantation: A systematic review

BACKGROUND

Liver transplantation is a life-saving therapy for end-stage liver disease patients, but acute cellular rejection (ACR) and graft complications remain significant postoperative challenges. Early and accurate diagnosis is crucial for timely intervention and improved patient outcomes, but their diagnosis rely currently on invasive biopsy sampling, thus prompting the search for non-invasive Biomarkers. MicroRNA (miRNA) have emerged as promising biomarkers in various pathological conditions, and their potential utility in diagnosing acute cellular rejection after liver transplantation has gained significant interest.

METHODS

This systematic review of PubMed, Web of Science, and the ClinicalTrials.gov registry analyzes studies exploring miRNA as biomarkers for ACR and graft dysfunction in liver transplantation (PROSPERO ID CRD42023465278). The Cochrane Collaboration tool for assessing risk of bias was employed. Population data, identified miRNA and their dynamic regulation, as well as event prediction were compared. Data extraction and quality assessment were performed independently by two reviewers.

RESULTS

Thirteen studies were included in this systematic review. Various investigated miRNAs were upregulated in association with acute cellular rejection, like miR-122, miR-155, miR-181, miR-483-3p, and miR-885-5p, demonstrating great biomarker potential. Additionally, several studies conducted target gene analysis, revealing insights into cellular mechanisms linked to ACR. Moreover, various miRNA were also capable of predicting different organ complications following transplantation, expanding their versatility. Remaining challenges include the standardization of miRNA profiling, the need for functional validation, and the necessity for long-term studies.

CONCLUSION

The results highlight the potential of miRNA as specific, non-invasive biomarkers for ACR and graft dysfunction following liver transplantation. However, further research is needed to validate these findings and establish standardized diagnostic panels to incorporate them into clinical practice and explore miRNA-based therapies in the future.

Risk and prediction of kidney failure early after liver transplantation

BACKGROUND

Kidney disease is common after liver transplantation (LT), but postoperative kidney failure is difficult to predict. Current guidelines recommend simultaneous liver-kidney transplantation (SLKT) in patients with pre-LT estimated glomerular filtration rate (eGFR) below 30-40 mL/min, which might be too liberal. The aim of this study was to evaluate the risk of kidney failure after LT. We also assessed the predictive ability of pretransplantation eGFR using various equations.

METHODS

This single-center study included patients undergoing primary LT 2006-2020. Patients undergoing simultaneous liver-kidney transplantations or on dialysis before LT were analysed separately. We calculated 5 different eGFR equations measured just before LT and assessed their predictive ability using Kaplan-Meier cumulative incidence estimates.

RESULTS

Among 556 LT patients with a median follow-up of 5.0 years (IQR 2.0-8.5), 20 developed kidney failure during follow-up, 7 of them within 1-year post LT. Six of these 7 suffered from major perioperative complications. Depending on the eGFR equation used, the incidence of kidney failure within 1-year was 3.9-6.7% at pre-LT eGFR-values <30 mL/min, 1.2-3.1% at eGFR 30-60 mL/min, and 0.6-0.9% at eGFR >60 mL/min.

CONCLUSIONS

Kidney failure within 1-year post-LT could not be reliably predicted by pre-LT eGFR. However, kidney failure was uncommon even in patients with severely reduced pre-LT glomerular filtration rate (eGFR <30 mL/min), and extremely rare in patients unaffected by major perioperative complications. Our data prompts further consideration regarding the guidelines for SLKT in patients with a reduced preoperative eGFR.

Effectiveness of metformin for the reversal of cold-ischemia-induced damage in hepatosteatosis

BACKGROUND

Primary dysfunction and rejection are more common in donor liver tissues with steatosis. AMP-activated protein kinase (AMPK) assumes organ-protective functions during ischemia. Metformin was used for the activation of AMPK in hepatocytes. The aim of this study is to investigate the effectiveness of metformin administration for the reversal of cold-ischemia-induced damage in hepatosteatosis.

MATERIAL AND METHODS

Seven-week-old C7BL56 male-mice (n = 109) were separated into four groups depending on diet type and metformin use. A specific diet model was followed for 10 weeks to induce hepatosteatosis. A group of the animals was administered with metformin for the last four weeks via oral gavage. After resection, the liver tissues were perfused and kept for 0-6-12-24 h in the UW solution. Histopathological examinations were performed, and Western blot was utilized to analyze p-AMPK and AMPK expression levels.

RESULTS

Hepatosteatosis decreased significantly with metformin. The steatotic liver group had more prominent pericentral inflammation, necrosis as well as showing a decreased and more delayed AMPK response than the non-fat group. All these alterations could be corrected using metformin.

CONCLUSION

Metformin can increase the resistance of livers with hepatosteatosis to cold-ischemia-induced damage, which in turn may pave the way for successful transplantation of fatty living-donor livers.

Immunosuppressive enzyme-responsive nanoparticles for enhanced accumulation in liver allograft to overcome acute rejection

Acute rejection is a life-threatening complication after liver transplantation. Immunosuppressants such as tacrolimus are used to inhibit acute rejection of liver grafts in clinic. However, inefficient intragraft accumulation may reduce the therapeutic outcomes of tacrolimus. Here, an enzyme-responsive nanoparticle is developed to selectively enhance the accumulation of tacrolimus in liver allograft through enzyme-induced aggregation to refine immunotherapeutic efficacy of tacrolimus. The nanoparticles are composed of amphiphilic tacrolimus prodrugs synthesized by covalently conjugating tacrolimus and matrix metalloproteinase 9 (MMP9)-cleavable peptide-containing methoxy poly (ethylene glycol) to poly (l-glutamic acid). Upon exposure to MMP9, which is overexpressed in rejected liver allografts, the nanoparticles undergo a morphological transition from spherical micellar nanoparticles to microscale aggregate-like scaffolds. Intravenous administration of MMP9-responsive nanoparticles into a rat model of acute liver graft rejection results in enhanced nanoparticle accumulation in allograft as compared to nonresponsive nanoparticles. Consequently, the MMP9-responsive nanoparticles significantly inhibit intragraft inflammatory cell infiltration and proliferation, maintain intragraft immunosuppressive environment, alleviate graft damage, improve liver allograft function, abate weight loss and prolong recipient survival. This work proves that morphology-switchable enzyme-responsive nanoparticles represent an innovative strategy for selectively enhancing intragraft accumulation of immunosuppressive agents to improve treatment of liver allograft rejection.

Postoperative alterations in ventriculoarterial coupling are an indicator of cardiovascular outcomes in liver transplant recipients

BACKGROUND

Liver transplantation (LT) increases the heart and vessel workload in patients with cirrhotic cardiomyopathy. While the interaction of the left ventricle (LV) with the arterial system (ventriculoarterial coupling, VAC) is a key determinant of cardiovascular performance, little is known about changes in VAC after LT. Therefore, we evaluated the relationship between VAC after LT and cardiovascular outcomes.

METHODS

344 consecutive patients underwent echocardiographic assessments before and within 30 days after LT. Non-invasive arterial elastance (Ea), LV end-systolic elastance (Ees), and LV end-diastolic elastance (Eed) were calculated. The postoperative outcomes included the development of major adverse cardiovascular events (MACE) and the length of stay in the intensive care unit and hospital.

RESULTS

A total of 240 patients were included in the analyses. After LT, Ea increased by 16% (P < 0.001), and Ees and contractility index of systolic velocity (S') increased by 18% (P < 0.001) and 7% (P < 0.001), respectively. The Eed increased by 6% (P < 0.001). The VAC remained unchanged (0.56 to 0.56, P = 0.912). Of these patients, 29 had MACE, and those with MACE had significantly higher postoperative VAC. Additionally, a higher postoperative VAC was an independent risk factor for a longer postoperative hospital stay (P = 0.038).

CONCLUSIONS

These data suggest that ventriculoarterial decoupling is associated with poor postoperative outcomes after LT.

Liver transplantation as an alternative for the treatment of intrahepatic cholangiocarcinoma: Past, present, and future directions

Intrahepatic cholangiocarcinoma (iCCA) is a rare biliary tract cancer with high mortality rate. Complete resection of the iCCA lesion is the first choice of treatment, with good prognosis after margin-negative resection. Unfortunately, only 12%-40% of patients are eligible for resection at presentation due to cirrhosis, portal hypertension, or large tumor size. Liver transplantation (LT) offers margin-negative iCCA extirpation for patients with unresectable tumors. Initially, iCCA was a contraindication for LT until size-based selection criteria were introduced to identify patients with satisfied post-LT outcomes. Recent studies have shown that tumor biology-based selection can yield high post-LT survival in patients with locally advanced iCCA. Another selection criterion is the tumor response to neoadjuvant therapy. Patients with response to neoadjuvant therapy have better outcomes after LT compared with those without tumor response to neoadjuvant therapy. Another index that helps predict the treatment outcome is the biomarker. Improved survival outcomes have also opened the door for living donor LT for iCCA. Patients undergoing LT for iCCA now have statistically similar survival rates as patients undergoing resection. The combination of surgery and locoregional and systemic therapies improves the prognosis of iCCA patients.

Conversion from twice-daily everolimus to once-daily sirolimus in long-term stable liver transplant recipients

BACKGROUND

After organ transplantation, strategies for simplifying the therapeutic regimen may improve adherence and prevent acute organ rejection and/or late graft loss. The present study aimed to evaluate the safety and efficacy of conversion from everolimus (EVR) twice daily to sirolimus (SIR) once daily in a large cohort of liver transplantation (LT) patients.

METHODS

We included 108 LT patients with at least 12 months of post-transplant follow-up and no rejection episodes in the last year. Conversion was based on a 1:1 ratio (but eventually adapted to available formulations of SIR).

RESULTS

The median age at the time of conversion was 68.9 years (range: 26.1-83.6); 75.0% were men. The main indications for mTOR inhibitor use were renal failure (38.9%) and/or a history of malignancy (37.0%). Median conversion time after LT was 14.8 years (range: 2.3-31.5). The median dose of EVR and SIR (initially) was 1.50 mg/day (range: 0.5-4.5). The mean follow-up after conversion was 15.8±4.4 months. Median serum EVR/SIR trough levels before/after conversion were 3.85 ng/mL vs. 6.32 ng/mL (p < 0.05), i.e. a 1:1.64 ratio. At the end of follow-up after conversion, the median dose of SIR was 1.25 mg/day (range: 0.5-3.5), and the mean serum SIR trough level was 5.23 ng/mL; 9 patients (8.3%) had returned to EVR, because of side effects (mainly digestive), that resolved thereafter. No biopsy-proven acute rejection episode was observed. Finally, 87.1% of patients considered the conversion beneficial and the cost was reduced by 50.3%.

CONCLUSION

The results of our study indicate that conversion from once-daily EVR to once-daily SIR in stable LT patients is safe, but needs dose adaptations and careful monitoring.

Impact of graft reperfusion on cardiac function assessed by transesophageal echocardiography during liver transplantation: an observational retrospective study

Cardiovascular instability is common during the reperfusion phase of orthotopic liver transplantation (OLT), and some patients experience a postreperfusion syndrome (PRS). However, there are no reports comparing the cardiac dysfunction between patients with PRS and those without. Thus, the aim of this study was to evaluate cardiac dysfunction in patients exhibiting PRS. This observational retrospective study included 34 patients who underwent OLT and were monitored with transesophageal echocardiography (TEE). The right ventricular/left ventricular (RV/LV) end diastolic area, tricuspid annular plane systolic excursion (TAPSE), left ventricular ejection fraction (LVEF) by Simpson method, pulsed Doppler of the mitral valve, and tissue Doppler motion of the mitral annulus were determined. Echocardiographic measurements were registered at the beginning of surgery and at 1 and 30 min after vascular unclamping. Patients with PRS (PRS group) were identified, and their echocardiographic parameters of ventricular function were compared with those in patients without PRS (non-PRS group). To check the evolution of diastolic-systolic dysfunction, general linear model-repeated measures were estimated. No patient presented systolic/diastolic dysfunction on the basal echocardiogram. One minute after vascular unclamping, the incidence of RV dilation was 4.5 times greater in patients with PRS (Cramer´s V > 0.6), and the incidence of RV systolic dysfunction was 62.5% in patients with PRS compared to 15.40% in patients without PRS (Cramer´s V = 0.45). The incidence of LV systolic dysfunction was 25% in patients with PRS compared to 0% in those without (Cramer´s V = 0.45), and left ventricular diastolic dysfunction was 4.8 times greater in patients with PRS (Cramer´s V = 0.45). No patient presented diastolic dysfunction type III. There were significant differences between groups in the evolutionary pattern at 1 and 30 min after unclamping for RV dilation (p = 0.008) and for TAPSE (p = 0.014). Liver graft reperfusion may alter cardiac function. Cardiac dysfunction was more frequent in patients with PRS. These patients exhibited temporary dysfunction of the RV associated with a varying degree of LV diastolic-systolic dysfunction. Trial registration: clinicaltrials.gov (NCT05175534). January 03, 2022; "retrospectively registered".

Liver transplantation as an alternative for the treatment of neuroendocrine liver metastasis: Appraisal of the current evidence

BACKGROUND

Liver transplantation (LT) for neuroendocrine liver metastases (NELM) is still in debate. Studies comparing LT with liver resection (LR) for NELM are scarce, as patient selection is heterogeneous and experience is limited. The goal of this review was to provide a critical analysis of the evidence on LT versus LR in the treatment of NELM.

DATA SOURCES

A scoping literature search on LT and LR for NELM was performed with PubMed, including English articles up to March 2023.

RESULTS

International guidelines recommend LR for NELM in resectable, well-differentiated tumors in the absence of extrahepatic metastatic disease with superior results of LR compared to systemic or liver-directed therapies. Advanced liver surgery has extended resectability criteria whilst entailing increased perioperative risk and short disease-free survival. In highly selected patients (based on the Milan criteria) with unresectable NELM, oncologic results of LT are promising. Prognostic factors include tumor biology (G1/G2) and burden, waiting time for LT, patient age and extrahepatic spread. Based on low-level evidence, LT for low-grade NELM within the Milan criteria resulted in improved disease-free survival and overall survival compared to LR. The benefits of LT were lost in patients beyond the Milan NELM-criteria.

CONCLUSIONS

With adherence to strict selection criteria especially tumor biology, LT for NELM is becoming a valuable option providing oncologic benefits compared to LR. Recent evidence suggests even stricter selection criteria with regard to tumor biology.

The learning curve of liver procurement from donation after circulatory death donor

PURPOSE

This study aimed to evaluate the learning curve for donation after circulatory death (DCD) liver procurement.

METHODS

DCD liver procurements performed by a single surgeon (n = 36) were separated into two phases: the learning and established phases.

RESULTS

A cumulative sum analysis using the operative donor warm ischemia time (oWIT) and donor hepatectomy time (dHT) showed that ten and seven cases, respectively, were needed for stable surgical procedures. The established phase (n = 26, since Case 11) was likely to have a shorter oWIT (p = 0.06; 7.5 min vs. 9 min) and dHT (p = 0.09; 32 min vs. 37 min) than the learning phase. While the hospital stay was significantly shorter and donor age was older in the established phase (p = 0.04 and p < 0.01; 12 days vs. 41 days and 38 years vs. 24 years, respectively), the incidence rates of post-transplant complications such as early allograft dysfunction (p = 0.74) and vascular complications (p = 0.53) were similar.

CONCLUSIONS

The learning curve for DCD liver procurement demonstrated that 10 cases were required to establish these techniques. The oWIT and dHT for DCD liver procurement can represent markers of operative efficiency.

Recovery of cardiac electrophysiological alterations by heart rate complexity based on multiscale entropy following liver transplantation

Autonomic nervous dysfunction is a known cardiac sequalae in patients with end-stage liver disease and is associated with a poor prognosis. Heart rate analysis using nonlinear models such as multiscale entropy (MSE) or complexity may identify marked changes in these patients where conventional heart rate variability (HRV) measurements do not. To investigate the application of heart rate complexity (HRC) based on MSE in liver transplantation settings. Thirty adult recipients of elective living donor liver transplantation were enrolled. HRV parameters using conventional HRV analysis and HRC analysis were obtained at the following time points: (1) 1 day before surgery, (2) postoperative day (POD) 7, (3) POD 14, (4) POD 90, and (5) POD 180. Preoperatively, patients with MELD score ≥ 25 had significantly lower HRC compared to patients with lower MELD scores. This difference in HRC disappeared by POD 7 following liver transplantation and subsequent analyses at POD 90 and 180 continued to show no significant difference. Our results indicated a significant negative correlation between HRC based on MSE analysis and liver disease severity preoperatively, which may be more sensitive than conventional linear HRV analysis. HRC in patients with MELD score ≧ 25 improved over time and became comparable to those with MELD < 25 as early as in 7 days.

Intraoperative kidney replacement therapy in acute liver failure

Paediatric acute liver failure (PALF) is often characterised by its rapidity of onset and potential for significant morbidity and even mortality. Patients often develop multiorgan dysfunction/failure, including severe acute kidney injury (AKI). Whilst the management of PALF focuses on complications of hepatic dysfunction, the associated kidney impairment can significantly affect patient outcomes. Severe AKI requiring continuous kidney replacement therapy (CKRT) is a common complication of both PALF and liver transplantation. In both scenarios, the need for CKRT is a poor prognostic indicator. In adults, AKI has been shown to complicate ALF in 25-50% of cases. In PALF, the incidence of AKI is often higher compared to other critically ill paediatric ICU populations, with reports of up to 40% in some observational studies. Furthermore, those presenting with AKI regularly have a more severe grade of PALF at presentation. Observational studies in the paediatric population corroborate this, though data are not as robust-mainly reflecting single-centre cohorts. Perioperative benefits of CKRT include helping to clear water-soluble toxins such as ammonia, balancing electrolytes, preventing fluid overload, and managing raised intracranial pressure. As liver transplantation often takes 6-10 h, it is proposed that these benefits could be extended to the intraoperative period, avoiding any hiatus. Intraoperative CKRT (IoCKRT) has been shown to be practicable, safe and may help sicker recipients tolerate the operation with outcomes analogous with less ill patients not requiring IoCKRT. Here, we provide a comprehensive guide describing the rationale, practicalities, and current evidence base surrounding IoCKRT during transplantation in the paediatric population.

COVID-19-associated secondary sclerosing cholangitis with liver transplantation

We report on two cases of orthotopic liver transplantation (OLTX) due to SARS-Cov2-associated secondary sclerosing cholangitis (SSC) following long-term artificial respiration and extra-corporal membrane oxygenation in intensive care. Under these conditions, SSC is a rapidly progredient biliary disease featuring degenerative cholangiopathy, loss of bile ducts, ductular and parenchymal cholestasis, biliary fibrosis, and finally cirrhosis. Reduced perfusion and oxygenation of the peribiliary plexus, severe concurrent infections, and secondary medico-toxic effects appear to play a crucial role in the pathogenesis of the disease. A direct cytopathic effect of SARS-Cov2 on endothelial cells followed by thrombosis and fibrosing obliteration in all parts of the vascular bed of the liver may enhance the virus-associated liver disease and particularly SSC.

Anastomosis selection in liver transplantation for recipients with unusable recipient hepatic arteries: a bayesian network meta-analysis

BACKGROUND

The anastomosis of donor and recipient hepatic arteries is standard in liver transplantations. For transplant recipients with unusable hepatic arteries, appropriate artery selection should be conducted using evidence-based considerations; therefore, this network meta-analysis (NMA) aimed to analyze the most suitable alternative recipient artery for anastomosis during liver transplantations.

METHODS

Comprehensive searches of the Scopus, Cochrane Library, and MEDLINE databases were conducted to analyze observational studies containing non-standard anastomoses in liver transplantations that used the splenic artery, aorta, celiac, or branches of the gastric artery. The outcome parameters included intraoperative components, complications, and survival data. This NMA used the BUGSnet package in R studio and the results were presented in a Forest plot, league table, and SUCRA plot.

RESULTS

Among the 13 studies included in this NMA, 5 arteries were used for the anastomoses. The splenic artery anastomosis showed a high risk of thrombosis and a low risk of stenosis (OR 1.12, 95% CI 0.13-3.14) and biliary tract abnormalities (OR 0.79, 95% CI 0.36-1.55). In addition, the graft survival (OR 1.08; 95% CI 0.96-1.23) and overall survival (1-year survival OR 1.09, 95% CI 0.94-1.26; 5-year survival OR 1.95% CI 0.83-1.22) showed favorable results using this artery. Constraints to the use of the splenic artery were longer operation and cold ischemic times. However, the duration of hospital stay (MD 1.36, 95% CI -7.47 to 10.8) was shorter than that when the other arteries were used, and the need for blood transfusions was minimal (MD -1.74, 95% CI -10.2 to 6.7).

CONCLUSION

In recipients with unusable hepatic arteries, the splenic artery of the patient should be the first consideration for anastomosis selection in liver transplantations.

Primary Sclerosing Cholangitis: Gender Effects in Valencia's Low-Prevalence Region

BACKGROUND AND AIMS

Recent studies point out to epidemiological changes in primary sclerosing cholangitis (PSC). Our aims were to determine in PSC patients followed in several centers in a Mediterranean geographic area: (i) changes in baseline features and (ii) effect of gender on clinical course.

METHODS

Retrospective multicenter study of PSC patients treated in 8 hospitals in a Mediterranean area between 2000 and 2021. Charts were reviewed compiling demographic, clinical, radiological, and histological variables.

RESULTS

Cohort of 112 PSC patients included, 42% women, 70% diagnosed after 2010. Women were increasingly diagnosed in recent cohorts. The median time from diagnosis to the combined endpoint liver transplantation (Lt) and/or death was 6.9 years. Asthenia at diagnosis (p = 0.009) was associated with lower transplant-free survival, while diagnosis before 2005 was associated with greater LT-free survival (p < 0.001). By Cox regression, LT-free survival was not influenced by age, sex, or cirrhosis at the time of diagnosis. Women were found to have less jaundice at diagnosis (2 vs 14%; p = 0.013), higher prevalence of ANA antibodies (43.9 vs 15.7%; p = 0.003), and lower GGT levels at diagnosis (GGT 123 vs 209U/L; p = 0.014) than men.

CONCLUSION

In an area traditionally considered to have low prevalence, the prevalence of affected women surpasses expectations based on existing literature. There appear to be gender-related variations in the presentation of the condition, highlighting the need for confirmation through larger-scale studies.

Routine utilization of machine perfusion in liver transplantation: Ready for prime time?

The last decade has been notable for increasing high-quality research and dramatic improvement in outcomes with dynamic liver preservation. Robust evidence from numerous randomized controlled trials has been pooled by meta-analyses, providing the highest available evidence on the protective effect of machine perfusion (MP) over static cold storage in liver transplantation (LT). Based on a protective effect with less complications and improved graft survival, the field has seen a paradigm shift in organ preservation. This editorial focuses on the role of MP in LT and how it could become the new "gold standard". Strong collaborative efforts are needed to explore its effects on long-term outcomes.