Excess mortality on the liver transplant waiting list: unintended policy consequences and Model for End-Stage Liver Disease (MELD) inflation

Comparisons of liver transplant from DCD outcomes in high-utilization centers versus low-utilization centers in the US: a systematic review and meta-analysis

Purpose/Objective

Donation after Cardiac Death (DCD) grafts are considered to be inferiors compared to Donation after Brain Death (DBD) grafts. Consequently, many transplant centers employ highly selective criteria for utilizing DCD, while others use them more liberally, potentially gaining greater expertise with this procedure. This disparity in approach raises questions about the impact of organ selection versus the benefits of increased experience with DCD organs. We performed a systematic review and meta-analysis to evaluate various outcomes in centers with high and low utilization rates of DCD.

Materials/Methods

Electronic databases PubMed, Embase, and Cochrane Library were systematically searched up to May 24th, 2023, for studies related to liver transplantation (LT). This search was conducted in accordance with PRISMA guidelines. The inclusion criteria focused on studies involving controlled DCD published within the last five years, and reporting on at least one of the outcomes of interest. Data was extracted and analyzed using a random-effects generalized linear mixed model with a 95% confidence interval (CI). The primary outcomes assessed were patient survival and graft survival. Heterogeneity among the included studies was evaluated using the I2 test, with I2>40% considered significant, and further explored through influence analysis. Subgroup meta-analysis by DCD utilization rate was done for each outcome. An analysis of the Organ Procurement & Transplantation Network (OPTN) database was performed on October 30th to determine the DCD rates and percentiles.

Results

Seven studies encompassing 898 patients were analyzed. In parallel, data from 151 centers were examined using the OPTN database, determining the rates of DCD utilization in each center over the past five years. Centers from the seven studies were divided into five high-utilization centers (HUC) and two low-utilization centers (LUC), with the 80th percentile (13.33% DCDs/Total LT) used as the threshold for high-utilization. Overall, the 1-year patient survival rate was 94.5% (95%CI: 92.4-96.1; I2 = 0%). HUCs had a rate of 94.6% (95%CI: 92.4-96.1; I2 = 0%), and LUCs had 93.7% (95%CI: 79.1-99.2; I2 = 0%), with a p=0.84. The overall 1-year graft survival rate was 90.6% (95% CI: 88.4-92.4; I2 = 0%). HUCs showed a 1-year graft survival of 90.9% (95%CI: 88.4-92.9; I2 = 0%), and LUCs showed 89.4% (95%CI: 83.8-93.2; I2 = 0%), p=0.54. The overall incidence of ischemic cholangiopathy was 10.3% (95% CI:7.9-13.3; I2 = 0%). The total rate of primary nonfunction was 1.5% (95% CI: 0.7-3.1%; I2 = 46%).

Conclusion

Our findings indicate no statistical difference in outcomes between high and low-utilization centers for DCD liver transplants, possibly suggesting that the higher selection in low-utilization centers is compensated by a greater experience in high-utilization centers.

Potential indications for liver transplant in Child-Pugh A and Model for End-stage Liver Disease exception for hepatocellular carcinoma in Japan

AIM

In 2019, expanded criteria for hepatocellular carcinoma (HCC), known as 5-5-500 (size ≤5 cm, number ≤5, alpha-fetoprotein ≤500 ng/mL), as well as Model for End-stage Liver Disease (MELD) exception, were implemented in Japan. In the present study, we evaluated liver transplantation indications and the Japanese allocation policy for HCC.

METHODS

Adults with HCC were evaluated between January 2013 and December 2017 in a multicenter study in Japan. The patients were aged ≤65 years, in line with the limits of Japanese transplant center limits.

RESULTS

HCC patients (n = 289) were classified as Child-Pugh A (74%), B (18%), or C (8%). Of these, 178 (62%) and 185 (64%) met the Milan and 5-5-500 criteria, respectively. The respective 1- and 5-year overall survival rates of patients who met the criteria were 100% and 88.1% in Child-Pugh A, 91.7% and 30.6% in B, and 72.9% and 0% in C without access to liver transplantation. For Child-Pugh A patients, we developed a risk score using the Child-Pugh score, des-gamma-carboxy prothrombin, tumor-node-metastasis stage grade, as well as albumin-bilirubin and albumin-bilirubin tumor-node-metastasis stage , which predicted worse prognosis. Additionally, we showed the characteristics of patients who achieved MELD exception points high enough to receive an organ: survival at least 2 years after waitlist registration, relatively good liver functional reserve, and sufficient tumor control with multiple treatments.

CONCLUSIONS

High-risk patients, identified by our scoring system and albumin-bilirubin tumor-node-metastasis stage ≥2 in Child-Pugh A, should be considered for liver transplantation eligibility. The allocation policy for HCC should be revised based on precise evaluations on a regular basis.

Factor V Serves as an Early Biomarker for Graft Loss After Liver Transplant: A Prospective Evaluation

BACKGROUND

Low post-operative day (POD) 1 Factor V has been retrospectively associated with graft loss after liver transplantation when stratified by a cutoff of 0.36 U/mL. We aimed to validate this prospectively.

METHODS

Patients transplanted at Toronto General Hospital were recruited (May 2018-March 2021). Factor V measurements were obtained on POD1-3, 5, and 7. Graft and patient survival at 3, 6, and 12 months were primary and secondary outcomes, respectively. We identified an optimal cutoff through receiver operating characteristic (ROC) analysis and the Youden index. Kaplan-Meier method and Log-rank tests were used to assess/compare survival.

RESULTS

One hundred and twenty-nine patients were included. One hundred and eight had Factor V >0.36 and 21 had ≤0.36 U/mL. This cutoff was predictive of 6- and 12-month graft survival and 12-month patient survival. With an optimal cutoff of 0.46 U/mL on POD1, 87 patients had Factor V >0.46 and 42 had ≤0.46 U/mL. Three-, 6-, and 12-month graft survival rates were 100%, 98.8%, and 98.8%, for patients with Factor V >0.46 U/mL, and 92.9%, 87.7%, and 87.7% for Factor V ≤0.46 U/mL. Similarly, 3-, 6-, and 12-month patient survival rates were 98.8%, 96.4%, and 95.0% for patients with Factor V >0.46 U/mL, and 92.9%, 88.0%, and 82.9% for Factor V ≤0.46 U/mL. Stratification below the novel cutoff was associated with decreased graft survival at months 3 (p = 0.012), 6 (p = 0.006), and 12 (p = 0.006), and decreased patient survival at 12 months (p = 0.022).

CONCLUSIONS

Factor V serves as an early biomarker for graft loss, with an optimal predictive cutoff of 0.46 U/mL in this prospective population. Validation of this new cutoff is necessary.

Association of nonstandardized model for end-stage liver disease score exceptions with waitlist mortality in adult liver transplant candidates

In the US liver allocation system, nonstandardized model for end-stage liver disease (MELD) exceptions (NSEs) increase the waitlist priority of candidates whose MELD scores are felt to underestimate their true medical urgency. We determined whether NSEs accurately depict pretransplant mortality risk by performing mixed-effects Cox proportional hazards models and estimating concordance indices. We also studied the change in frequency of NSEs after the National Liver Review Board's implementation in May 2019. Between June 2016 and April 2022, 60,322 adult candidates were listed, of whom 10,280 (17.0%) received an NSE at least once. The mean allocation MELD was 23.9, an increase of 12.0 points from the mean laboratory MELD of 11.9 (P < .001). A 1-point increase in allocation MELD score due to an NSE was associated with, on average, a 2% reduction in hazard of pretransplant death (cause-specific hazard ratio: 0.98; 95% CI: 0.96, 1.00; P = .02) compared with those with the same laboratory MELD. Laboratory MELD was more accurate than allocation MELD with NSEs in rank-ordering candidates (c-index: 0.889 vs 0.857). The proportion of candidates with NSEs decreased significantly after the National Liver Review Board from 21.5% to 12.8% (P < .001). NSEs substantially increase the waitlist priority of candidates with objectively low medical urgency.

Systematic Sex-Based Inequity in the MELD Score-Based Allocation System for Liver Transplantation in Germany

In liver allocation systems based on the Model for End-stage Liver Disease (MELD) score, sex inequities have been identified in countries with high organ donation rates. Whether similar inequities exist in regions with average to low donation rates remained unclear. We assessed the impact of sex on transplantation rates, waiting list mortality and post-transplant survival in 25,943 patients waitlisted for liver transplantation in Germany between 2003 and 2017 using competing risk analysis. Women are currently underrepresented on the waiting list (33.3%) and among transplant recipients (31.1%) compared to their proportion of severe liver disease cases (35.1%). The introduction of MELD-based allocation has worsened this disadvantage [HR before: 0.89 (0.81-0.98), after: 0.77 (0.74-0.81)]. Three key factors contribute to this disparity: Women have lower creatinine levels despite worse renal function, reducing their MELD score (median 1, 0-3). Second, exceptional MELD points are more frequently granted to men [HR 1.61 (1.54-1.69) compared to regular allocation]. Third, the small height of women has the highest impact on the probability of not being transplanted [adjusted HR 0.85 (0.81-0.9)]. Even in countries with lower organ donation rates, MELD-based allocation leads to sex inequity. Measures are needed to ensure sex-neutral liver allocation in MELD-based systems worldwide.

Wogonin Alleviates DCD Liver Ischemia/Reperfusion Injury by Regulating ALOX15/iNOS-mediated Ferroptosis

BACKGROUND

Donation after circulatory death livers are more susceptible to ischemia/reperfusion injury (IRI) because of a longer period of warm ischemia. Growing evidence now suggests that ferroptosis plays a key regulatory role in the development of IRI, so targeting ferroptosis may be an effective strategy to alleviate IRI in liver transplantation (LT).

METHODS

Using donation after circulatory death LT models in rats and oxygen-glucose deprivation/reoxygenation (OGD/R) models in BRL-3A cells, we tested the effect of the Chinese medicine monomer wogonin on liver IRI and explored the specific mechanism.

RESULTS

Wogonin attenuated liver IRI and increased the survival rate of rats by inhibiting lipid peroxidation and ferroptosis. Mechanistically, arachidonic acid 15-lipoxygenase-1 (ALOX15) and inducible nitric oxide synthase (iNOS) were identified as potential targets of baicalein through bioinformatics analysis combined with in vivo and in vitro experiments. This result was further confirmed by molecular docking and cellular thermal shift assays. Finally, we silenced ALOX15 and iNOS in the OGD/R cell model and found that silencing ALOX15 and iNOS could reproduce the regulatory effect of wogonin and abrogate the regulatory effect of wogonin.

CONCLUSIONS

In brief, this study emphasizes that wogonin exerts a protective effect in liver IRI through the regulation of ALOX15- and iNOS-mediated ferroptosis. ALOX15 and iNOS are potential targets for intervention in IRI induced by LT, and wogonin is a drug candidate for LT patients.

Median Meld at Transplant Minus 3 Reduces the Mortality of Non-Hepatocellular Carcinoma Patients on the Liver Transplant Waitlist

Liver transplants (LTs) are prioritized by mortality risk, which is estimated by MELD scores. Since hepatocellular carcinoma (HCC) patients present with lower MELD scores, they are allocated MELD exception points. Concerns persist that HCC recipients are over-prioritized, resulting in disproportionate waitlist mortality among non-HCC patients. We assessed whether the Median Meld at Transplant minus 3 (MMaT-3) scoring system would balance waitlist mortality and transplantation rates between HCC and non-HCC patients. We reviewed 266 patient charts listed for an LT from 2015 to 2023; 46.2% were listed in the MMaT-3 era. Amongst non-HCC patients, MMaT-3 implementation significantly increased 1-year transplant rate and reduced 1-year waitlist mortality among non-HCC patients (p = 0.003). Pre-MMaT-3 gaps in transplantation (p = 0.004) and waitlist dropout (p = 0.01) were eliminated post-implementation (p > 0.05). Amongst HCC patients, MMaT-3 implementation had no impact on the 1-year transplant rate (p = 0.92) or 1-year waitlist mortality (p = 0.66). Fine-gray proportional hazard multivariable analysis revealed that MMaT-3 significantly reduced waitlist mortality among non-HCC patients (asHR: 0.44, 95% CI [0.23, 0.83], p = 0.01) and limited impact on HCC patients (p = 0.31). MMaT-3 allocation did not significantly alter 2-year post-transplant survival for both populations. We show that the MMaT-3 system decreased the waitlist mortality of non-HCC patients with limited impacts on outcomes for HCC patients listed for an LT.

Risk factors for biliary strictures and leaks after living-donor liver transplantation: a systematic review and meta-analysis

BACKGROUND

Liver transplantation is the only curative treatment of end-stage liver disease. Unfortunately, a significant number of patients on the organ waitlist die waiting for an organ. Living-donor liver transplantation (LDLT) is an approach that has been used to expand organ availability. Although LDLT has excellent outcomes, biliary complications remain a significant drawback. This meta-analysis aimed to precisely assess the predictors of biliary stricture and leak after LDLT.

METHODS

PubMed, Embase, and Web of Science databases were searched from inception to January 2024. Only studies that used a multivariate model to assess risk factors for post-LDLT biliary stricture or leak in adult participants were included. Studies reporting unadjusted risk factors were excluded. Pooled adjusted odds ratios (ORs) and pooled hazard ratios (HRs) with 95% CIs for risk factors reported in ≥2 studies were obtained within a random-effects model.

RESULTS

Overall, 22 studies with 9442 patients who underwent LDLT were included. The post-LDLT biliary stricture rate was 22%, whereas the post-LDLT biliary leak rate was 14%. In addition, 13 unique risk factors were analyzed. Postoperative bile leak (OR, 4.10 [95% CI, 2.88-5.83]; HR, 3.88 [95% CI, 2.15-6.99]) was the most significant predictor of biliary stricture after LDLT. Other significant predictors of biliary stricture after LDLT were right lobe graft (OR, 2.56; 95% CI, 1.23-5.32), multiple ducts for anastomosis (OR, 1.62; 95% CI, 1.08-2.43), ductoplasty (OR, 2.07; 95% CI, 1.36-3.13), ABO incompatibility (OR, 1.45; 95% CI, 1.16-1.81), and acute cellular rejection (OR, 4.10; 95% CI, 2.88-5.83). Donor bile duct size (HR, 0.82; 95% CI, 0.74-0.91; P = .001, I2 = 0%) was found to be significantly associated with reduced risk of post-LDLT biliary stricture. Donor age, recipient age, recipient male sex, and duct-to-duct anastomosis were not associated with an increased risk of post-LDLT biliary strictures. Multiple ducts for anastomosis (OR, 1.86; 95% CI, 1.43-2.43) was a significant predictor of post-LDLT biliary leak. Recipient age, warm ischemia time, and duct-to-duct anastomosis were not associated with an increased risk of post-LDLT biliary leak.

CONCLUSION

In this meta-analysis, 7 unique risk factors were shown to be predictive of post-LDLT biliary stricture, one of which was associated with both post-LDLT biliary stricture and leak. Donor bile duct size was found to be protective against post-LDLT biliary strictures. Identifying reliable predictors is crucial for recognizing high-risk patients. This approach can facilitate the implementation of preventive measures, surveillance protocols, and targeted interventions to reduce the incidence of biliary strictures after LDLT.

Inconsistent values and algorithmic fairness: a review of organ allocation priority systems in the United States

BACKGROUND

The Organ Procurement and Transplant Network (OPTN) Final Rule guides national organ transplantation policies, mandating equitable organ allocation and organ-specific priority stratification systems. Current allocation scores rely on mortality predictions.

METHODS

We examined the alignment between the ethical priorities across organ prioritization systems and the statistical design of the risk models in question. We searched PubMed for literature on organ allocation history, policy, and ethics in the United States.

RESULTS

We identified 127 relevant articles, covering kidney (19), liver (60), lung (24), and heart transplants (23), and transplant accessibility (1). Current risk scores emphasize model performance and overlook ethical concerns in variable selection. The inclusion of race, sex, and geographical limits as categorical variables lacks biological basis; therefore, blurring the line between evidence-based models and discrimination. Comprehensive ethical and equity evaluation of risk scores is lacking, with only limited discussion of the algorithmic fairness of the Model for End-Stage Liver Disease (MELD) and the Kidney Donor Risk Index (KDRI) in some literature. We uncovered the inconsistent ethical standards underlying organ allocation scores in the United States. Specifically, we highlighted the exception points in MELD, the inclusion of race in KDRI, the geographical limit in the Lung Allocation Score, and the inadequacy of risk stratification in the Heart Tier system, creating obstacles for medically underserved populations.

CONCLUSIONS

We encourage efforts to address statistical and ethical concerns in organ allocation models and urge standardization and transparency in policy development to ensure fairness, equitability, and evidence-based risk predictions.

The future of liver transplantation

Over the last 50 years, liver transplantation has evolved into a procedure routinely performed in many countries worldwide. Those able to access this therapy frequently experience a miraculous risk-benefit ratio, particularly if they face the imminently life-threatening disease. Over the decades, the success of liver transplantation, with dramatic improvements in early posttransplant survival, has aggressively driven demand. However, despite the emergence of living donors to augment deceased donors as a source of organs, supply has lagged far behind demand. As a result, rationing has been an unfortunate focus in recent decades. Recent shifts in the epidemiology of liver disease combined with transformative innovations in liver preservation suggest that the underlying premise of organ shortage may erode in the foreseeable future. The focus will sharpen on improving equitable access while mitigating constraints related to workforce training, infrastructure for organ recovery and rehabilitation, and their associated costs. Research efforts in liver preservation will undoubtedly blossom with the aim of optimizing both the timing and conditions of transplantation. Coupled with advances in genetic engineering, regenerative biology, and cellular therapies, the portfolio of innovation, both broad and deep, offers the promise that, in the future, liver transplantation will not only be broadly available to those in need but also represent a highly durable life-saving therapy.

Improved Waitlist Outcomes in Liver Transplant Patients With Mid-MELD-Na Scores Listed in Centers Receptive to Use of Organs Donated After Circulatory Death

BACKGROUND

Liver transplant (LT) using organs donated after circulatory death (DCD) has been increasing in the United States. We investigated whether transplant centers' receptiveness to use of DCD organs impacted patient outcomes.

METHODS

Transplant centers were classified as very receptive (group 1), receptive (2), or less receptive (3) based on the DCD acceptance rate and DCD transplant percentage. Using organ procurement and transplantation network/UNOS registry data for 20 435 patients listed for LT from January 2020 to June 2022, we compared rates of 1-y transplant probability and waitlist mortality between groups, broken down by model for end-stage liver disease-sodium (MELD-Na) categories.

RESULTS

In adjusted analyses, patients in group 1 centers with MELD-Na scores 6 to 29 were significantly more likely to undergo transplant than those in group 3 (aHR range 1.51-2.11, P  < 0.001). Results were similar in comparisons between groups 1 and 2 (aHR range 1.41-1.81, P  < 0.001) and between groups 2 and 3 with MELD-Na 15-24 (aHR 1.19-1.20, P  < 0.007). Likewise, patients with MELD-Na score 20 to 29 in group 1 centers had lower waitlist mortality than those in group 3 (scores, 20-24: aHR, 0.71, P  = 0.03; score, 25-29: aHR, 0.51, P  < 0.001); those in group 1 also had lower waitlist mortality compared with group 2 (scores 20-24: aHR0.69, P  = 0.02; scores 25-29: aHR 0.63, P  = 0.03). One-year posttransplant survival of DCD LT patients did not vary significantly compared with donation after brain dead.

CONCLUSIONS

We conclude that transplant centers' use of DCD livers can improve waitlist outcomes, particularly among mid-MELD-Na patients.

The impact of surging transplantation of alcohol-associated liver disease on transplantation for HCC and other indications

BACKGROUND

Liver transplantation (LT) for alcohol-associated liver disease (ALD) is increasing and may impact LT outcomes for patients listed for HCC and other indications.

METHODS

Using US adults listed for primary LT (grouped as ALD, HCC, and other) from October 8, 2015, to December 31, 2021, we examined the impact of center-level ALD LT volume (ATxV) on waitlist outcomes in 2 eras: Era 1 (6-month wait for HCC) and Era 2 (MMaT-3). The tertile distribution of ATxV (low to high) was derived from the listed candidates as Tertile 1 (T1): <28.4%, Tertile 2 (T2): 28.4%-37.6%, and Tertile 3 (T3): >37.6% ALD LTs per year. Cumulative incidence of waitlist death and LT within 18 months from listing by LT indication were compared using the Gray test, stratified on eras and ATxV tertiles. Multivariable competing risk regression estimated the adjusted subhazard ratios (sHRs) for the risk of waitlist mortality and LT with interaction effects of ATxV by LT indication (interaction p).

RESULTS

Of 56,596 candidates listed, the cumulative waitlist mortality for those with HCC and other was higher and their LT probability was lower in high (T3) ATxV centers, compared to low (T1) ATxV centers in Era 2. However, compared to ALD (sHR: 0.92 [0.66-1.26]), the adjusted waitlist mortality for HCC (sHR: 1.15 [0.96-1.38], interaction p = 0.22) and other (sHR: 1.13 [0.87-1.46], interaction p = 0.16) were no different suggesting no differential impact of ATxV on the waitlist mortality. The adjusted LT probability for HCC (sHR: 0.89 [0.72-1.11], interaction p = 0.08) did not differ by AtxV while it was lower for other (sHR: 0.82 [0.67-1.01], interaction p = 0.02) compared to ALD (sHR: 1.04 [0.80-1.34]) suggesting a differential impact of ATxV on LT probability.

CONCLUSIONS

The high volume of LT for ALD does not impact waitlist mortality for HCC and others but affects LT probability for other in the MMAT-3 era warranting continued monitoring.

Expanding the liver donor pool worldwide with hepatitis C infected livers, is it the time?

Liver transplantation (LT) provides a life-saving option for cirrhotic patients with complications and hepatocellular carcinoma. Despite the increasing number of liver transplants performed each year, the number of LT candidates on the waitlist remains unchanged due to an imbalance between donor organ supply and the demand which increases the waitlist time and mortality. Living donor liver transplant had a great role in increasing the donor pool and shortened waitlist time for LT candidates. Nevertheless, further strategies can be implemented to increase the pool of potential donors in deceased donor LT, such as reducing the rate of organ discards. Utilizing hepatitis C virus (HCV) seropositive liver grafts is one of the expanded donor organ criteria. A yearly increase of hundreds of transplants is anticipated as a result of maximizing the utilization of HCV-positive organs for HCV-negative recipients. Direct-acting antiviral therapy's efficacy has revolutionized the treatment of HCV infection and the use of HCV-seropositive donors in transplantation. The American Society of Transplantation advises against performing transplants from HCV-infected liver donors (D+) into HCV-negative recipient (R-) unless under Institutional Review Board-approved study rules and with full informed consent of the knowledge gaps associated with such transplants. Proper selection of patients to be transplanted with HCV-infected grafts and confirming their access to direct-acting antivirals if needed is important. National and international consensuses are needed to regulate this process to ensure the maximum benefit and the least adverse events.

Regional Social Vulnerability is Associated With Geographic Disparity in Waitlist Outcomes for Patients With Non-Hepatocellular Carcinoma Model for End-stage Liver Disease Exceptions in the United States

OBJECTIVE

This study was undertaken to evaluate the role of regional social vulnerability in geographic disparity for patients listed for liver transplantation with non-hepatocellular carcinoma (HCC) model for end-stage liver disease (MELD) exceptions.

SUMMARY AND BACKGROUND

Prior work has demonstrated regional variability in the appropriateness of MELD exceptions for diagnoses other than HCC.

METHODS

Adults listed at a single center for first-time liver-only transplantation without HCC after June 18, 2013 in the Scientific Registry of Transplant Recipients database as of March 2021 were examined. Candidates were mapped to hospital referral regions (HRRs). Adjusted likelihood of mortality and liver transplantation were modeled. Advantaged HRRs were defined as those where exception patients were more likely to be transplanted, yet no more likely to die in adjusted analysis. The Centers for Disease Control's Social Vulnerability Index (SVI) was used as the measure for community health. Higher SVIs indicate poorer community health.

RESULTS

There were 49,494 candidates in the cohort, of whom 4337 (8.8%) had MELD exceptions. Among continental US HRRs, 27.3% (n = 78) were identified as advantaged. The mean SVI of advantaged HRRs was 0.42 versus 0.53 in nonadvantaged HRRs ( P = 0.002), indicating better community health in these areas. Only 25.3% of advantaged HRRs were in spatial clusters of high SVI versus 40.7% of nonadvantaged HRRs, whereas 44.6% of advantaged HRRs were in spatial clusters of low SVI versus 38.0% of nonadvantaged HRRs ( P = 0.037).

CONCLUSIONS

An advantage for non-HCC MELD exception patients is associated with lower social vulnerability on a population level. These findings suggest assigning similar waitlist priority to all non-HCC exception candidates without considering geographic differences in social determinants of health may actually exacerbate rather than ameliorate disparity.

Ferroptosis: a new target for hepatic ischemia-reperfusion injury?

Ischemia-reperfusion injury (IRI) can seriously affect graft survival and prognosis and is an unavoidable event during liver transplantation. Ferroptosis is a novel iron-dependent form of cell death characterized by iron accumulation and overwhelming lipid peroxidation; it differs morphologically, genetically, and biochemically from other well-known cell death types (autophagy, necrosis, and apoptosis). Accumulating evidence has shown that ferroptosis is involved in the pathogenesis of hepatic IRI, and targeting ferroptosis may be a promising therapeutic approach. Here, we review the pathways and phenomena involved in ferroptosis, explore the associations and implications of ferroptosis and hepatic IRI, and discuss possible strategies for modulating ferroptosis to alleviate the hepatic IRI.

Assessment of Liver Transplant Eligibility in Chronic Liver Disease Patients: A Cross-Sectional Study From a Tertiary Care Hospital of Pakistan

INTRODUCTION

The burden of chronic liver disease (CLD) is increasing globally and the ultimate treatment is a liver transplant. As Pakistan is a developing country, liver transplantation is not easily available due to limited resources. This study aims to assess the patients with CLD for liver transplantation and to find the frequency of eligible candidates for liver transplantation.

METHODS

A cross-sectional observational study was conducted on patients with CLD from June 2022 to December 2022. Total bilirubin, serum creatinine complete blood count, serum electrolytes, and international normalised ratio (INR) were done. The Model for End-Stage Liver Disease (MELD) score was calculated and the frequency of eligible patients for liver transplant was determined. Data was entered and analyzed using Statistical Package for Social Sciences (SPSS) version 22 (IBM Corp., Armonk, NY, USA).

RESULTS

In our study, 149 patients were enrolled with a mean age of 46.81±15.7 years. There were 58.7% male and 41.6% female patients. The mean duration of liver cirrhosis was 18.22±11.7 months. The mean MELD score was 20.71±5.2. The common liver cirrhosis stages were stage II and stage II was found in 32.2% of each. Hepatocellular carcinoma (HCC) was present in 15.4% of patients. There were 25.5% of patients eligible for liver transplants.

CONCLUSION

In our study, we found that significant numbers of patients with CLD were eligible for liver transplantation.

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.

Chronic Liver Disease and Cirrhosis Mortality Rates Are Disproportionately Increasing in Younger Women in the United States Between 2000-2020

BACKGROUND & AIMS

Previous studies show that mortality from chronic liver disease (CLD) and cirrhosis is increasing in the United States. However, there are limited data on sex-specific mortality trends by age, race, and geographical location. The aim of this study was to conduct a comprehensive time-trend analysis of liver disease-related mortality rates in the National Center of Health Statistics (NCHS) database.

METHODS

CLD and cirrhosis mortality rates between 20002020 (age-adjusted to the 2000 standard U.S. population) were collected from the NCHS database and categorized by sex and age into older adults (≥55 years) and younger adults (<55 years), race (Non-Hispanic-White, Non-Hispanic-Black, Hispanic, Non-Hispanic-American-Indian/Alaska-Native, and Non-Hispanic-Asian/Pacific-Islander), U.S. state, and cirrhosis etiology. Time trends, annual percentage change (APC), and average APC (AAPC) were estimated using Joinpoint Regression using Monte Carlo permutation analysis. We used tests for parallelism and identicalness for sex-specific pairwise comparisons of mortality trends (two-sided P value cutoff = .05).

RESULTS

Between 20002020, there were 716,651 deaths attributed to CLD and cirrhosis in the U.S. (35.68% women). In the overall population and in older adults, CLD and cirrhosis-related mortality rates were increasing similarly in men and women. However, in younger adults (246,149 deaths, 32.72% women), the rate of increase was greater in women compared with men (AAPC = 3.04 vs 1.08, AAPC-difference = 1.96; P < .001), with non-identical non-parallel data (P values < .001). The disparity was driven by Non-Hispanic-White (AAPC = 4.51 vs 1.79, AAPC-difference = 2.71; P < .001) and Hispanic (AAPC = 1.89 vs -0.65, AAPC-difference = 2.54; P = .001) individuals. The disparity varied between U.S. states and was seen in 16 states, mostly in West Virginia (AAPC = 4.96 vs 0.88, AAPC-difference = 4.08; P < .001) and Pennsylvania (AAPC = 2.81 vs -1.02, AAPC-difference = 3.84; P < .001). Etiology-specific analysis did not show significant sex disparity in younger adults.

CONCLUSIONS

Mortality rates due to CLD and cirrhosis in the U.S. are increasing disproportionately in younger women. This finding was driven by higher rates in Non-Hispanic White and Hispanic individuals, with variation between U.S. states. Future studies are warranted to identify the reasons for these trends with the ultimate goal of improving outcomes.

Survival benefit from liver transplantation for patients with and without hepatocellular carcinoma

Background & Aims

In the USA, inequal liver transplantation (LT) access exists between patients with and without hepatocellular carcinoma (HCC). Survival benefit considers survival without and with LT and could equalise LT access. We calculated bias-corrected LT survival benefit for patients with(out) HCC who underwent a transplant, based on longitudinal data in a recent United States cohort.

Methods

Adult LT candidates with(out) HCC between 2010 and 2019 were included. Waitlist survival over time was contrasted to post-transplant survival, to estimate 5-year survival benefit from the moment of LT. Waitlist survival was modelled with a bias-corrected Cox regression, and post-transplant survival was estimated through Cox proportional hazards regression.

Results

Mean HCC survival without LT was always lower than non-HCC waitlist survival. Below model for end-stage liver disease (sodium) (MELD(-Na)) 30, patients with HCC gained more life-years from LT than patients without HCC at the same MELD(-Na) score. Only patients without HCC below MELD(-Na) 9 had negative benefit. Most patients with HCC underwent a transplant below MELD(-Na) 14, and most patients without HCC underwent a transplant above MELD(-Na) 26. Liver function [MELD(-Na), albumin] was the main predictor of 5-year benefit. Therefore, during 5 years, most patients with HCC gained 0.12 to 1.96 years from LT, whereas most patients without HCC gained 2.48 to 3.45 years.

Conclusions

On an individual level, performing a transplant in patients with HCC resulted in survival benefit. However, on a population level, benefit was indirectly decreased, as patients without HCC were likely to gain more survival owing to decreased liver function. For patients who underwent a transplant, a constructed online calculator estimates 5-year survival benefit given specific patient characteristics. Survival benefit scores could serve to equalise LT access.

Impact and implications

Benefit is a comparison of the survival with and without liver transplantation, and it is important when deciding who should undergo a transplant. Liver function is most important when predicting possible benefit from transplantation. Patients with liver cancer die sooner on the waiting list than similar patients without liver cancer. However, patients with liver cancer more often have better liver function. Most patients without liver cancer derive more benefit from transplantation than patients with liver cancer.

Liver transplantation for iatrogenic bile duct injury: a systematic review

BACKGROUND

Bile duct injury (BDI) is an infrequent but serious complication of cholecystectomy, often with life-changing consequences. Liver transplantation (LT) may be required following severe BDI, however given the rarity, few large studies exist to guide management for complex BDI.

METHODS

A systematic review was performed to assess post-operative complications, 30-day mortality, retransplant rate and 1-year and 5-year survival following LT for BDI in Medline, EMBASE, Web of Science or Cochrane Clinical Trials Database.

RESULTS

Seven articles met inclusion criteria, describing 179 patients that underwent LT for BDI. Secondary biliary cirrhosis (SBC) was the main indication for LT (82.2% of patients). Median model for end-stage liver disease (MELD) scores at time of LT ranged from 16 to 20.5. Median 30-day mortality was 20.0%. The 1-year and 5-year survival ranges were 55.0-84.3% and 30.0-83.3% respectively, and the overall retransplant rate was 11.5%.

CONCLUSION

BDI is rarely indicated for LT, predominantly for SBC following multiple prior interventions. MELD scores poorly reflect underlying morbidity, and exception criteria for waitlisting may avoid prolonged LT waiting times. 30-day mortality was higher than for non-BDI indications, with comparable long term survival, suggesting that LT remains a viable but high risk salvage option for severe BDI.

Benefit and harm of waiting time in liver transplantation for HCC

Liver transplantation is the most successful treatment for limited-stage HCC. The waiting time for liver transplantation (LT) can be a critical factor affecting the oncological prognosis and outcome of patients with HCC. Efficient strategies to optimize waiting time are essential to maximize the benefits of LT and to reduce the harm of delay in transplantation. The ever-increasing demand for donor livers emphasizes the need to improve the organization of the waiting list for transplantation and to optimize organ availability for patients with and without HCC. Current progress in innovations to expand the donor pool includes the implementation of living donor LT and the use of grafts from extended donors. By expanding selection criteria, an increased number of patients are eligible for transplantation, which necessitates criteria to prevent futile transplantations. Thus, the selection criteria for LT have evolved to include not only tumor characteristics but biomarkers as well. Enhancing our understanding of HCC tumor biology through the analysis of subtypes and molecular genetics holds significant promise in advancing the personalized approach for patients. In this review, the effect of waiting time duration on outcome in patients with HCC enlisted for LT is discussed.

Preservation of Mitochondrial Health in Liver Ischemia/Reperfusion Injury

Liver ischemia-reperfusion injury (LIRI) is a major cause of the development of complications in different clinical settings such as liver resection and liver transplantation. Damage arising from LIRI is a major risk factor for early graft rejection and is associated with higher morbidity and mortality after surgery. Although the mechanisms leading to the injury of parenchymal and non-parenchymal liver cells are not yet fully understood, mitochondrial dysfunction is recognized as a hallmark of LIRI that exacerbates cellular injury. Mitochondria play a major role in glucose metabolism, energy production, reactive oxygen species (ROS) signaling, calcium homeostasis and cell death. The diverse roles of mitochondria make it essential to preserve mitochondrial health in order to maintain cellular activity and liver integrity during liver ischemia/reperfusion (I/R). A growing body of studies suggest that protecting mitochondria by regulating mitochondrial biogenesis, fission/fusion and mitophagy during liver I/R ameliorates LIRI. Targeting mitochondria in conditions that exacerbate mitochondrial dysfunction, such as steatosis and aging, has been successful in decreasing their susceptibility to LIRI. Studying mitochondrial dysfunction will help understand the underlying mechanisms of cellular damage during LIRI which is important for the development of new therapeutic strategies aimed at improving patient outcomes. In this review, we highlight the progress made in recent years regarding the role of mitochondria in liver I/R and discuss the impact of liver conditions on LIRI.

Despite Increasing Costs, Perfusion Machines Expand the Donor Pool of Livers and Could Save Lives

INTRODUCTION

Liver transplantation is a highly successful treatment for liver failure and disease. However, demand continues to outstrip our ability to provide transplantation as a treatment. Many livers initially considered for transplantation are not used because of concerns about their viability or logistical issues. Recent clinical trials have shown discarded livers may be viable if they undergo machine perfusion, which allows a more objective assessment of liver quality.

METHODS

Using the Scientific Registry of Transplant Recipients dataset, we examined discarded and unretrieved organs to determine their eligibility for perfusion. We then used a Markov decision-analytic model to perform a cost-effectiveness analysis of two competing transplant strategies: Static Cold Storage (SCS) alone versus Static Cold Storage and Normothermic Machine Perfusion (NMP) of discarded organs.

RESULTS

The average predicted successful transplants after perfusion was 385, representing a 5.8% increase in the annual yield of liver transplants. Our cost-effectiveness analysis found that the SCS strategy generated 4.64 quality-adjusted life years (QALYs) and cost $479,226. The combined SCS + NMP strategy generated 4.72 QALYs and cost $481,885. The combined SCS + NMP strategy had an incremental cost-effectiveness ratio of $33,575 per additional QALY over the 10-year study horizon.

CONCLUSIONS

Machine perfusion of livers currently not considered viable for transplant could increase the number of transplantable grafts by approximately 5% per year and is cost-effective compared to Static Cold Storage alone.

"I am in other people's hands as regards my health" A sociological critique of health care encounters of people with cirrhosis. A secondary analysis

OBJECTIVES

People with cirrhosis are encouraged to participate in shared decision-making with their doctors, but studies suggest that doctors limit the amount of information that is shared. In this study we explore the presence of medical power in clinical encounters in 2015 from a patient perspective and highlight its effects on healthcare interactions.

METHODS

Qualitative semi-structured interviews were conducted with ten people with cirrhosis attending a tertiary liver transplant centre in southern England. We explored their understanding of their disease and prognosis, and their participation in decision-making. Using the lens of medical power as a framework, we analysed findings into thematic sentences to summarise key ideas whilst preserving the complexity of identified concepts.

RESULTS

Three key concepts explained patient perspectives of their communication with doctors: (1) portraying a positive image to doctors, (2) avoiding confrontation with doctors, (3) feeling powerless in the face of doctors' medical knowledge. These concepts show deeper dynamic issues of power during healthcare encounters, illustrated by participants' reluctance to voice their concerns and express themselves, challenge decisions, or seek information.

CONCLUSION

People with cirrhosis struggle to articulate their concerns or challenge decisions on their care and treatment and may worry about potential consequences. Our findings demonstrate the continuing persistence of issues of power at play in contemporary health care.

INDICATION FOR LIVER TRANSPLANTATION DUE TO HEPATOCELLULAR CARCINOMA: ANALYSIS OF 1,706 PROCEDURES OVER THE PAST DECADE IN THE STATE OF PARANÁ

BACKGROUND

Patients listed for liver transplantation and hepatocellular carcinoma are considered priority on the waiting list, and this could overly favor them.

AIM

This study aimed to evaluate the impact of this prioritization.

METHODS

We analyzed the liver transplants performed in adults from 2011 to 2020 and divided into three groups: adjusted Model of End-Stage Liver Disease (MELD) score for hepatocellular carcinoma, other adjusted Model of End-Stage Liver Disease situations, and no adjusted Model of End-Stage Liver Disease.

RESULTS

A total of 1,706 patients were included in the study, of which 70.2% were male. Alcoholism was the main etiology of cirrhosis (29.6%). Of the total, 305 patients were with hepatocellular carcinoma, 86 with other adjusted Model of End-Stage Liver Disease situations, and 1,315 with no adjusted Model of End-Stage Liver Disease. Patients with hepatocellular carcinoma were older (58.9 vs. 53.5 years). The predominant etiology of cirrhosis was viral hepatitis (60%). The findings showed that group with adjusted Model of End-Stage Liver Disease had lower physiological Model of End-Stage Liver Disease (10.9), higher adjusted Model of End-Stage Liver Disease (22.6), and longer waiting list time (131 vs. 110 days), as compared to the group with no adjusted Model of End-Stage Liver Disease. The total number of transplants and the proportion of patients transplanted for hepatocellular carcinoma increased from 2011 to 2020. There was a reduction in the proportion of patients with hepatocellular carcinoma and adjusted Model of End-Stage Liver Disease of 20 and there was an increase on waiting list time in this group. There was an increase in the proportion of those with adjusted Model of End-Stage Liver Disease of 24 and 29, but the waiting list time remained stable.

CONCLUSION

Over the past decade, prioritization of hepatocellular carcinoma resulted in an increased proportion of transplanted patients in relation to those with no priority. It also increased waiting list time, requiring higher adjusted Model of End-Stage Liver Disease to transplant an organ.

Low utilization of adult-to-adult LDLT in Western countries despite excellent outcomes: International multicenter analysis of the US, the UK, and Canada

BACKGROUND & AIMS

Adult-to-adult living donor liver transplantation (LDLT) offers an opportunity to decrease the liver transplant waitlist and reduce waitlist mortality. We sought to compare donor and recipient characteristics and post-transplant outcomes after LDLT in the US, the UK, and Canada.

METHODS

This is a retrospective multicenter cohort-study of adults (≥18-years) who underwent primary LDLT between Jan-2008 and Dec-2018 from three national liver transplantation registries: United Network for Organ Sharing (US), National Health Service Blood and Transplantation (UK), and the Canadian Organ Replacement Registry (Canada). Patients undergoing retransplantation or multi-organ transplantation were excluded. Post-transplant survival was evaluated using the Kaplan-Meier method, and multivariable adjustments were performed using Cox proportional-hazards models with mixed-effect modeling.

RESULTS

A total of 2,954 living donor liver transplants were performed (US: n = 2,328; Canada: n = 529; UK: n = 97). Canada has maintained the highest proportion of LDLT utilization over time (proportion of LDLT in 2008 - US: 3.3%; Canada: 19.5%; UK: 1.7%; p <0.001 - in 2018 - US: 5.0%; Canada: 13.6%; UK: 0.4%; p <0.001). The 1-, 5-, and 10-year patient survival was 92.6%, 82.8%, and 70.0% in the US vs. 96.1%, 89.9%, and 82.2% in Canada vs. 91.4%, 85.4%, and 66.7% in the UK. After adjustment for characteristics of donors, recipients, transplant year, and treating transplant center as a random effect, all countries had a non-statistically significantly different mortality hazard post-LDLT (Ref US: Canada hazard ratio 0.53, 95% CI 0.28-1.01, p = 0.05; UK hazard ratio 1.09, 95% CI 0.59-2.02, p = 0.78).

CONCLUSIONS

The use of LDLT has remained low in the US, the UK and Canada. Despite this, long-term survival is excellent. Continued efforts to increase LDLT utilization in these countries may be warranted due to the growing waitlist and differences in allocation that may disadvantage patients currently awaiting liver transplantation.

LAY SUMMARY

This multicenter international comparative analysis of living donor liver transplantation in the United States, the United Kingdom, and Canada demonstrates that despite low use of the procedure, the long-term outcomes are excellent. In addition, the mortality risk is not statistically significantly different between the evaluated countries. However, the incidence and risk of retransplantation differs between the countries, being the highest in the United Kingdom and lowest in the United States.

Current Approaches in the Allocation of Liver Transplantation

In recent decades, important advances have been made in the field of liver transplantation. One of the major problems remaining in this area is the small number of donors. Thus, recent data bring multiple updates of the indications and contraindications of this therapeutic method. The main goal is to increase the number of patients who can benefit from liver transplantation, a therapeutic method that can improve life expectancy and the quality of life of patients with end-stage liver disease. Another goal in the management of these patients is represented by the optimal care of those on the waiting list during that period. A multidisciplinary team approach is necessary to obtain the best results for both the donor and the recipient.

Lost potential and missed opportunities for DCD liver transplantation in the United States

BACKGROUND

Donation after cardiac death(DCD) has been proposed as an avenue to expand the liver donor pool.

METHODS

We examined factors associated with nonrecovery of DCD livers using UNOS data from 2015 to 2019.

RESULTS

There 265 non-recovered potential(NRP) DCD livers. Blood type AB (7.8% vs. 1.1%) and B (16.9% vs. 9.8%) were more frequent in the NRP versus actual donors (p < 0.001). The median driving time between donor hospital and transplant center was similar for NRP and actual donors (30.1 min vs. 30.0 min; p = 0.689), as was the percentage located within a transplant hospital (20.8% vs. 20.9%; p = 0.984).The donation service area(DSA) of a donor hospital explained 27.9% (p = 0.001) of the variability in whether a DCD liver was recovered.

CONCLUSION

A number of potentially high quality DCD donor livers go unrecovered each year, which may be partially explained by donor blood type and variation in regional and DSA level practice patterns.

Artificial intelligence and liver transplantation: Looking for the best donor-recipient pairing

Decision-making based on artificial intelligence (AI) methodology is increasingly present in all areas of modern medicine. In recent years, models based on deep-learning have begun to be used in organ transplantation. Taking into account the huge number of factors and variables involved in donor-recipient (D-R) matching, AI models may be well suited to improve organ allocation. AI-based models should provide two solutions: complement decision-making with current metrics based on logistic regression and improve their predictability. Hundreds of classifiers could be used to address this problem. However, not all of them are really useful for D-R pairing. Basically, in the decision to assign a given donor to a candidate in waiting list, a multitude of variables are handled, including donor, recipient, logistic and perioperative variables. Of these last two, some of them can be inferred indirectly from the team's previous experience. Two groups of AI models have been used in the D-R matching: artificial neural networks (ANN) and random forest (RF). The former mimics the functional architecture of neurons, with input layers and output layers. The algorithms can be uni- or multi-objective. In general, ANNs can be used with large databases, where their generalizability is improved. However, they are models that are very sensitive to the quality of the databases and, in essence, they are black-box models in which all variables are important. Unfortunately, these models do not allow to know safely the weight of each variable. On the other hand, RF builds decision trees and works well with small cohorts. In addition, they can select top variables as with logistic regression. However, they are not useful with large databases, due to the extreme number of decision trees that they would generate, making them impractical. Both ANN and RF allow a successful donor allocation in over 80% of D-R pairing, a number much higher than that obtained with the best statistical metrics such as model for end-stage liver disease, balance of risk score, and survival outcomes following liver transplantation scores. Many barriers need to be overcome before these deep-learning-based models can be included for D-R matching. The main one of them is the resistance of the clinicians to leave their own decision to autonomous computational models.

The MELD upgrade exception: a successful strategy to optimize access to liver transplantation for patients with high waiting list mortality

BACKGROUND

MELD exceptions are designed to equipoise liver transplant waiting list survival. We aimed to analyze the impact of the MELD Upgrade rule and all other MELD exceptions on the liver transplant waiting list outcomes during 2012-2017 in Switzerland.

METHODS

We conducted a nationwide cohort study including all adult patients registered on the Swiss liver transplant waiting list between 2012 and 2017. Waiting list mortality and access to transplantation were analyzed, considering MELD exceptions as time-dependent covariates.

RESULTS

730 patients were included. Patients with MELD Upgrade exceptions had a higher risk of dying while on the waiting list (OR 2.13; CI 95% 1.30-3.47) and also an increased likelihood of receiving a liver transplantation, when compared to patients without MELD exceptions. Patients with any type of MELD exceptions were more likely to be transplanted when compared to patients without MELD exceptions. The proportion of patients with MELD exceptions increased from 2012 to 2017 (44% vs 88%). Allocation MELD at the time of transplantation showed an annual increase (23 ± 8 points vs 32 ± 5 points, p < 0.001).

CONCLUSION

Only patients with MELD Upgrade exceptions had the expected combination of higher waiting list mortality and quicker access to liver transplantation.

Health-Related Quality of Life in Colorectal Cancer Patients Treated With Liver Transplantation Compared to Chemotherapy

Liver transplantation (LT) for patients with non-resectable colorectal liver metastases (CRLM) offers improved survival and has gained increased interest internationally the last years. The aim of this study was to describe the health-related quality of life (HRQoL) in patients with non-resectable CRLM receiving LT and how baseline HRQoL factors affect overall survival (OS). HRQoL data in the SECA (SEcondary CAncer) LT cohort was compared to data obtained from colorectal cancer patients starting first-line chemotherapy for metastatic disease in a clinical trial and data from a Norwegian normal population. HRQoL data from the QLQ-C30 questionnaire used in the SECA LT study and the NORDIC- VII study were reported. The relationship between patient-reported symptom burden at baseline and OS was investigated. In the SECA study longitudinal HRQoL assessment was used to describe the time until definitive deterioration as well as mean values at different time points. Patients in the SECA and NORDIC-VII studies reported similar baseline HRQoL. The median time until definitive deterioration in the transplanted patients was estimated to 36 months. In the SECA study appetite loss and pain at baseline had negative impact on OS (25.3 versus 71.7 months, p = 0.002 and 39.7 versus 71.7 months, p = 0.038, respectively). Despite a relapse in most of the LT patients the Global Health Score (GHS) remained good. Pain, and especially appetite loss at time of transplantation is associated with poor outcome after LT.

Liver transplantation for patients with hepatocellular carcinoma: Its current status and advances

Liver transplantation is one of the best treatment options for selected patients with hepatocellular carcinoma (HCC). The Milan criteria (a single tumor with a maximum size of 5 cm or two or three tumors with a maximum size of 3 cm without evidence of vascular or extrahepatic involvement or metastasis) are one of the most common criteria to select patients with HCC for transplantation, though they are considered too restrictive. A moderate expansion of the criteria has been found to yield comparable recurrence-free survival rates. HCC will recur in approximately 10% of patients, and mostly within the first 2 years after transplantation. The preoperative level of alpha-fetoprotein, macrovascular invasion, tumor size, and tumor number are prognostic factors for recurrence. Recurrence of HCC after transplantation results in a poor prognosis.

The Need to Update Endpoints and Outcome Analysis in the Rapidly Changing Field of Liver Transplantation

Liver transplantation (LT) survival rates have continued to improve over the last decades, mostly due to the reduction of mortality early after transplantation. The advancement is facilitating a liberalization of access to LT, with more patients with higher risk profiles being added to the waiting list. At the same time, the persisting organ shortage fosters strategies to rescue organs of high-risk donors. This is facilitated by novel technologies such as machine perfusion. Owing to these developments, reconsideration of the current and emerging endpoints for the assessment of the efficacy of existing and new therapies is warranted. While conventional early endpoints in LT have focused on the damage induced to the parenchyma, the fate of the bile duct and the recurrence of the underlying disease have a stronger impact on the long-term outcome. In light of this evolving landscape, we here attempt to reflect on the appropriateness of the currently used endpoints in the field of LT trials.

The Toronto Postliver Transplantation Hepatocellular Carcinoma Recurrence Calculator: A Machine Learning Approach

Liver transplantation (LT) listing criteria for hepatocellular carcinoma (HCC) remain controversial. To optimize the utility of limited donor organs, this study aims to leverage machine learning to develop an accurate posttransplantation HCC recurrence prediction calculator. Patients with HCC listed for LT from 2000 to 2016 were identified, with 739 patients who underwent LT used for modeling. Data included serial imaging, alpha-fetoprotein (AFP), locoregional therapies, treatment response, and posttransplantation outcomes. We compared the CoxNet (regularized Cox regression), survival random forest, survival support vector machine, and DeepSurv machine learning algorithms via the mean cross-validated concordance index. We validated the selected CoxNet model by comparing it with other currently available recurrence risk algorithms on a held-out test set (AFP, Model of Recurrence After Liver Transplant [MORAL], and Hazard Associated with liver Transplantation for Hepatocellular Carcinoma [HALT-HCC score]). The developed CoxNet-based recurrence prediction model showed a satisfying overall concordance score of 0.75 (95% confidence interval [CI], 0.64-0.84). In comparison, the recalibrated risk algorithms' concordance scores were as follows: AFP score 0.64 (outperformed by the CoxNet model, 1-sided 95% CI, >0.01; P = 0.04) and MORAL score 0.64 (outperformed by the CoxNet model 1-sided 95% CI, >0.02; P = 0.03). The recalibrated HALT-HCC score performed well with a concordance of 0.72 (95% CI, 0.63-0.81) and was not significantly outperformed (1-sided 95% CI, ≥0.05; P = 0.29). Developing a comprehensive posttransplantation HCC recurrence risk calculator using machine learning is feasible and can yield higher accuracy than other available risk scores. Further research is needed to confirm the utility of machine learning in this setting.

Human Amnion-Derived Mesenchymal Stromal Cells: A New Potential Treatment for Carbapenem-Resistant Enterobacterales in Decompensated Cirrhosis

BACKGROUND

Spontaneous bacterial peritonitis (SBP) is a severe and often fatal infection in patients with decompensated cirrhosis and ascites. The only cure for SBP is antibiotic therapy, but the emerging problem of bacterial resistance requires novel therapeutic strategies. Human amniotic mesenchymal stromal cells (hA-MSCs) possess immunomodulatory and anti-inflammatory properties that can be harnessed as a therapy in such a context.

METHODS

An in vitro applications of hA-MSCs in ascitic fluid (AF) of cirrhotic patients, subsequently infected with carbapenem-resistant Enterobacterales, was performed. We evaluated the effects of hA-MSCs on bacterial load, innate immunity factors, and macrophage phenotypic expression.

RESULTS

hA-MSCs added to AF significantly reduce the proliferation of both bacterial strains at 24 h and diversely affect M1 and M2 polarization, C3a complement protein, and ficolin 3 concentrations during the course of infection, in a bacterial strain-dependent fashion.

CONCLUSION

This study shows the potential usefulness of hA-MSC in treating ascites infected with carbapenem-resistant bacteria and lays the foundation to further investigate antibacterial and anti-inflammatory roles of hA-MSC in in vivo models.

Applicability of the UK DCD Risk Score in the modern era of liver transplantation: a U.S. update

Careful graft and recipient selection have resulted in improved outcomes in liver transplantation (LT) using donation after cardiac death (DCD) organs. The UK DCD Risk Score was established as a risk stratification tool to guide selection. We evaluated the applicability of the UK DCD Risk Score in a contemporary US cohort of adult DCD LT recipients using the United Network for Organ Sharing registry (2011-2020). 3,899 DCD LTs were included in our study (UK DCD Risk Score 0-5 points: 1,438 [36.9%], 6-9 points: 1,920 [49.2%]; 10-20 points: 541 [13.9%]). Compared to a score of 6-9 points, a score of 0-5 points was associated with decreased risk of graft loss (HR = 0.80, 95%CI: 0.68-0.94, P = 0.006), while a score of 10-20 points was associated with increased risk of graft loss (HR = 1.23, 95%CI: 1.01-1.51, P = 0.04). The 5-year graft survival for patients with risk scores of 0-5, 6-9, and 10-20 were 75.9%, 71.7%, and 67.9%, respectively. The C-statistic for the UK DCD Risk Score in our contemporary cohort was 0.611. The UK DCD Risk Score demonstrates a more limited ability to differentiate recipient outcomes in the modern era of DCD LT in the US. Acceptable long-term outcomes are achievable for patients stratified to the highest-risk group. This article is protected by copyright. All rights reserved.

Artificial neural network for prediction of acute kidney injury after liver transplantation for cirrhosis and hepatocellular carcinoma

Acute kidney injury (AKI) has serious consequences on the prognosis of patients undergoing liver transplantation (LT) for liver cancer and cirrhosis. Artificial neural network (ANN) has recently been proposed as a useful tool in many fields in the setting of solid organ transplantation and surgical oncology, where patient prognosis depends on a multidimensional and nonlinear relationship between variables pertaining to the surgical procedure, the donor (graft characteristics), and the recipient comorbidities. In the specific case of LT, ANN models have been developed mainly to predict survival in patients with cirrhosis, to assess the best donor-to-recipient match during allocation processes, and to foresee postoperative complications and outcomes. This is a specific opinion review on the role of ANN in the prediction of AKI after LT for liver cancer and cirrhosis, highlighting potential strengths of the method to forecast this serious postoperative complication.

Clinical outcomes after ABO-incompatible liver transplantation: A systematic review and meta-analysis

BACKGROUND

ABO-incompatible liver transplantation (ABOi-LT) is increasingly used to overcome donor shortage. Evidence about disadvantage and advantage in comparison with ABO-compatible liver transplantation (ABOc-LT) needs to be performed in the early and late periods. Herein, We compared the short-term and long-term outcomes between ABOi-LT and ABOc-LT cohorts.

METHODS

We performed a meta-analysis based on the observation studies which included outcomes at ≥1 year after ABOi-LT and ABOc-LT procedures, based on the MEDLINE (via Pubmed), the Cochrance Central Register of Controlled Trials (CENTRAL), and EMBASE (via Ovid) systems. Two researchers independently screened each study according to the pre-established inclusion and exclusion criteria to assess the quality of each study and extracted data from published studies. The primary outcome indicators were all-cause mortality and graft survival at 1, 3 and 5 years after transplantation. In the meta-analysis, we based on the value of heterogeneity using a fixed-effect and a random-effect. A fixed-effect model was used if the value of I2 was less than or equal 50%; and a random-effect model was used if the value of I2 was greater than 50%.

FINDINGS

Out of 335 identified records, 29 records with 10,783 patients with liver transplants; 2137 of them were ABOi-LTs and the remaining 8646 were ABOc-LTs. There was no significant difference at 1-year, 3-year, and 5-year in all-cause mortality, death-censored graft survival and complication incidence rate between ABO-incompatible living donor liver transplantation (ABOi-LDLT) group and ABO-compatible living donor liver transplantation (ABOc-LDLT) group. Compared with ABO-compatible deceased donor liver transplantation (ABOc-DDLT), ABO-incompatible deceased donor liver transplantation (ABOi-DDLT) had a higher 1-year all-cause mortality, and the value of totally pooled odds ratio (OR) was 1.89 (1.28,2.80). However, there was no significant difference at 3-year and 5-year all-cause mortality between ABOi-DDLT and ABOc-DDLT groups. ABOi-DDLT group had a lower 1-year and 5-year death-censored graft survival than ABOc-DDLT, as the value of totally pooled OR was 1.91 (1.41,2.60) and 1.52 (1.12,2.05), respectively. No significant difference was detected at 3-year death-censored graft survival between ABOi-DDLT and ABOc-DDLT groups. ABOi-DDLT group had a higher complication incidence rate than ABOc-DDLT, and the value of totally pooled OR was 2.26 (1.53,3.33). We found no obvious bias except for the complication of living donor liver transplantation (LDLT; P = 0.038).

IN CONCLUSION

The short-term and long-term outcomes were worse after ABOi-DDLT than ABOc-DDLT in the all-cause mortality, death-censored graft survival, and complication incidence rate. However, the same outcomes were essentially comparable between ABOi-LDLT vs. ABOc-LDLT cohorts. Considering the current shortage of liver donors, we believe that ABOi-LT from living donor and deceased donors can save lives under emergency situations.

Liver Transplant Center Size and The Impact on the Clinical Outcomes and Resource Utilization

BACKGROUND

Prior studies suggest that transplant center volume is associated with liver transplantation (LT) outcomes. We compared patient characteristics and waitlist outcomes among transplant centers in the U.S. with different volumes.

METHODS

Data for adult waitlisted candidates and LT recipients in the U.S. between 2008 and 2017 were extracted from the Scientific Registry of Transplant Recipients database. Transplant centers were categorized by transplants/year into tertiles:low-volume centers (LVCs; <20 transplantations per year)medium-volume centers (MVCs; 20-55 transplantations per year)high-volume centers (HVCs; >55 transplantations per year)Patient characteristics, waitlist outcomes, and factors associated with post-transplantation mortality were compared.

RESULTS

From 141 centers, 112,110 patients were waitlisted for LT: 6% at LVCs, 26% at MVCs, and 68% at HVCs. Patients listed in LVCs were less likely to have private insurance but had higher Medicaid and Veterans Affairs healthcare rates. Patients at LVCs were less likely to receive LT (47% vs. 53% in MVC vs. 61% in HVC), had higher transfer rates to other centers, and were more likely to be removed from the waitlist. In competing risk survival analysis, adjusted for center location, MELD score, and clinico-demographic factors, patients listed at an HVC were more likely to receive LT (aHR:1.30; 95%CI= 1.27-1.33; P<0.001). Among LT-recipients (n=62,131), receiving a transplant at an LVC was associated with higher post-LT mortality (aHR:1.16; 95%CI=1.05-1.28; P=0.003).

CONCLUSION

Patients in LVCs were less likely to receive a LT and a higher risk of post-LT death.Supplemental Visual Abstract; http://links.lww.com/TP/C274.

Exploring patients' perceptions and experiences of treatments for the prevention of variceal bleeding: a qualitative study

BACKGROUND

The most common fatal complication of liver cirrhosis is haemorrhaging caused by variceal rupture. The prevention of the first variceal bleed is, therefore, an important clinical goal. Little is known about patients' experience of treatments geared towards this, or of their perceptions of treatments prior to being exposed to them.

AIMS

To explore the factors impacting patient preference for, and actual experience of carvedilol and variceal band ligation.

METHODS

Semistructured interviews were conducted with 30 patients from across the UK at baseline, prior to random allocation to either carvedilol or variceal band ligation. Twenty patients were interviewed a second time at 6-month follow-up. Five patients who declined the trial were also interviewed. Data were analysed using thematic analysis.

RESULTS

There was no clear preference for either treatment pathway at baseline. Key factors reported by patients to influence their treatment preference included: negative experiences with key treatment processes; how long-term or short-term treatment was perceived to be; treatment misconceptions; concerns around polypharmacy and worries around treatment adherence. Patient treatment experience was influenced by their perceptions of treatment effectiveness; clinical surveillance; clinician interaction and communication, or lack thereof. Carvedilol-specific experience was also influenced by the manifestation of side effects and patient dosage routine. Variceal band ligation-specific experience was positively influenced by the use of sedation, and negatively influenced by the procedure recovery period.

CONCLUSIONS

These data do not support a view that the patient experience of beta-blockade for prevention of variceal bleeds is likely to be superior to variceal band ligation.

Serum exosomal long noncoding RNA nuclear-enriched abundant transcript 1 predicts 90-day mortality in acute-on-chronic hepatitis B liver failure

Objectives: Acute-on-chronic hepatitis B liver failure (ACHBLF) is characterized by high short-term mortality, calling for accurate prognostic biomarkers. This study aims to evaluate the predictive value of serum exosomal long noncoding RNA nuclear-enriched abundant transcript 1 (lncRNA NEAT1) for 90-day mortality of ACHBLF.Methods: This prospective study consisted of 113 ACHBLF patients from June 2013 to June 2017 as a training cohort and 72 ACHBLF patients from July 2017 to June 2020 as a validating cohort. LncRNA NEAT1 was detected using quantitative real-time polymerase chain reaction from serum exosomes.Results: LncRNA NEAT1 levels were higher in non-survivors than survivors (P< 0.01). In the training cohort, lncRNA NEAT1 (HR 1.049, 95%CI 1.023-1.075, P< 0.001) was an independent predictor for 90-day mortality of ACHBLF. Meanwhile, lncRNA NEAT1 showed significantly higher area under the curve of receiver operating characteristic (AUC) than MELD score in the training and validation cohort (P< 0.05, respectively). However, no significant difference was found in AUC between lncRNA NEAT1 and NEAT1 plus MELD score (P> 0.05). ACHBLF patients with lncRNA NEAT1 levels above 1.92 showed poorer survival condition than those below (P< 0.01).Conclusions: The serum exosomal lncRNA NEAT1 might be a better prognostic biomarker than MELD score for 90-day mortality of ACHBLF.

Human Amnion-Derived Mesenchymal Stromal Cells in Cirrhotic Patients with Refractory Ascites: A Possible Anti-Inflammatory Therapy for Preventing Spontaneous Bacterial Peritonitis

Cirrhosis is associated with dysregulated immune cell activation and immune dysfunction. These conditions modify gut flora, facilitate bacterial translocation, and increase susceptibility to bacterial peritonitis and consequent systemic infections by dramatically affecting long-term patient survival. Human amnion-derived mesenchymal stromal cells (hA-MSCs) exert immunomodulatory potential benefit, and have the ability to modulate their actions, especially in situations requiring immune activation through mechanisms not fully understood. In this study, we aimed to investigate, in vitro, the immunostimulant or immunosuppressive effects of hA-MSCs on cellular components of ascitic fluid obtained from cirrhotic patients with refractory ascites. We found that hA-MSCs viability is not affected by ascitic fluid and, interestingly, hA-MSCs diminished the pro-inflammatory cytokine production, and promoted anti-inflammatory M2 macrophage polarization. Moreover, we found that there was no simultaneous significant decrease in the M1-like component, allowing a continual phagocytosis activity of macrophages and NK cells to restore a physiological condition. These data highlight the plasticity of hA-MSCs' immunomodulatory capacity, and pave the way to further understanding their role in conditions such as spontaneous bacterial peritonitis.

The Heterogenous Effect of COVID-19 on Liver Transplantation Activity and Waitlist Mortality in the United States

Background: The COVID-19 pandemic curtailed the practice of liver transplantation (LT), which lacks a temporizing life-saving measure for candidates on the waitlist. Aims/Objectives: The objective of this research was to (1) determine the effect of decreased LT activity on waitlist mortality in the United States and (2) assess if this effect was homogenous across the country. Methods: We conducted a retrospective, cross-sectional analysis utilizing United Network for Organ Sharing (UNOS) data assessing 3,600 liver transplants from January 1, 2020 to June 2, 2020. COVID-19 incidence data was taken directly from the New York Times case count. Results: During weeks 10 to 15 of 2020, there was a 38% reduction in the number of LTs performed nationally, which was temporally associated with a transient 97% increase in waitlist mortality. When stratified by UNOS region, waitlist mortality was inversely correlated with the number of LTs performed in all 11 regions. However, the range of the association strength (r) was large (Pearson correlation coefficient range: -0.73 to -0.01). Conclusion: Interruptions in LT activity due to COVID-19 were associated with rapid increases in waitlist mortality, and these effects were unevenly distributed among candidates across the United States. The transplant community can utilize these results to mitigate inequalities in transplant allocation between UNOS regions and advocate for the uninterrupted practice of LT should another pandemic surge or COVID-19 variant arise.

Comparison of results on the use of extended criteria liver doners for transplants in Espírito Santo

INTRODUCTION

liver Transplantation is currently the treatment of choice for several terminal liver diseases. Despite the increase in performed transplants, the waiting lists continue to increase. In order to expand the supply of organs, transplantation teams have started to use previously rejected livers for transplants because of an increased risk of unfavorable outcomes.

OBJECTIVE

to evaluate the use of livers of expanded criterion donators.

METHODS

retrospective study of medical records. The livers were classified as normal or expanded criteria. The groups were divided in low and high MELD. A multivariate analysis was performed through logistic regression.

RESULTS

there was no statistical difference regarding early, late and global mortality between the groups. Decreased survival was observed in patients with high MELD (higher or equal to 20) when they received grafts from expanded criterion donators. The association between the occurrence of cardiorespiratory arrest and presence of elevated total bilirubin in donators was associated with higher mortality rates in expanded criterion livers.

CONCLUSION

the overall results are similar, but expanded criteria liver donators was associated with higher mortality in patients with high MELD.

Liver Transplantation Selection and Allocation Criteria for Hepatocellular Carcinoma: A European Perspective

For patients with early-stage hepatocellular carcinoma (HCC), liver transplantation offers the best chance of cure. Over the past two decades, selection criteria to determine eligibility for liver transplantation have been constantly refined but a fair allocation strategy of liver grafts to HCC patients remains challenging. In Europe, over a dozen transplantation networks apply different liver transplantation criteria for HCC patients. In this review, we explore and compare candidate selection and liver graft allocation strategies for patients with HCC with a European perspective and discuss the ethical and technical challenges involved. In addition, we suggest possible paths for future improvement such as transitioning from fixed selection and allocation criteria to a more flexible model of benefit, which includes criteria concerning the graft, response to treatment, the biology of the tumor, and other relevant recipient factors.

Changing Trends in Liver Transplantation: Challenges and Solutions

Despite improvements in postliver transplant outcomes through refinements in perioperative management and surgical techniques, several changing trends in liver transplantation have presented challenges. Mortality on the waitlist remains high. In the United States, Europe, and the United Kingdom, there is an increasing need for liver transplantation, primarily as a result of increased incidence of nonalcoholic steatohepatitis-related cirrhosis and cancer indications. Meanwhile, donor suitability has decreased, as donors are often older and have more comorbidities. Despite a mismatch between organ need and availability, many organs are discarded. Notwithstanding this, many solutions have been developed to overcome these challenges. Innovative techniques in allograft preservation, viability assessment, and reconditioning have allowed the use of suboptimal organs with adequate results. Refinements in surgical procedures, including live donor liver transplantations, have increased the organ pool and are decreasing the time and mortality on the waitlist. Despite many challenges, a similar number of solutions and prospects are on the horizon. This review seeks to explore the changing trends and challenges in liver transplantation and highlight possible solutions and future directions.

Liver Transplantation for T2 Hepatocellular Carcinoma during the COVID-19 Pandemic: A Novel Model Balancing Individual Benefit against Healthcare Resources

Simple Summary

Using Italian national data from more than 8000 patients, we proposed a novel model calculating the net benefit of liver transplantation (individual benefit minus harm to others on the waiting list) in T2 hepatocellular carcinoma (HCC) patients in different scenarios of transplant activity reduction. Our results show that the transplant net benefit is closely related to the decrease in the number of organs, but it is also higher in T2 HCC patients than in non-HCC patients with the same model for end-stage liver disease (MELD) scores. Our model supports liver transplantation for T2 HCC with the highest net benefit also during crises such as COVID-19.

Abstract

The COVID-19 pandemic caused temporary drops in the supply of organs for transplantation, leading to renewed debate about whether T2 hepatocellular carcinoma (HCC) patients should receive priority during these times. The aim of this study was to provide a quantitative model to aid decision-making in liver transplantation for T2 HCC. We proposed a novel ethical framework where the individual transplant benefit for a T2 HCC patient should outweigh the harm to others on the waiting list, determining a “net benefit”, to define appropriate organ allocation. This ethical framework was then translated into a quantitative Markov model including Italian averages for waiting list characteristics, donor resources, mortality, and transplant rates obtained from a national prospective database (n = 8567 patients). The net benefit of transplantation in a T2 HCC patient in a usual situation varied from 0 life months with a model for end-stage liver disease (MELD) score of 15, to 34 life months with a MELD score of 40, while it progressively decreased with acute organ shortage during a pandemic (i.e., with a 50% decrease in organs, the net benefit varied from 0 life months with MELD 30, to 12 life months with MELD 40). Our study supports the continuation of transplantation for T2 HCC patients during crises such as COVID-19; however, the focus needs to be on those T2 HCC patients with the highest net survival benefit.

Validation of the Model for End-stage Liver Disease sodium (MELD-Na) score in the Eurotransplant region

The MELD score is used in the Eurotransplant (ET) region to allocate liver grafts. Hyponatremia in cirrhotic patients is an important predictor of death but is not incorporated in MELD. This study investigated the performance of the MELD-Na score for the ET region. All adult patients with chronic liver disease on the ET liver transplantation waiting list (WL) allocated through lab MELD scores were included. The MELD-corrected effect of serum sodium (Na) concentration at listing on the 90-day WL mortality was calculated using Cox regression. The MELD-Na performance was assessed with c-indices, calibration per decile and Brier scores. The reclassification from MELD to MELD-Na score was calculated to estimate the impact of MELD-Na-based allocation in the ET region. For the 5223 included patients, the risk of 90-day WL death was 2.9 times higher for hyponatremic patients. The MELD-Na had a significantly higher c-index of 0.847 (SE 0.007) and more accurate 90-day mortality prediction compared to MELD (Brier score of 0.059 vs 0.061). It was estimated that using MELD-Na would reduce WL mortality by 4.9%. The MELD-Na score yielded improved prediction of 90-day WL mortality in the ET region and using MELD-Na for liver allocation will very likely reduce WL mortality.

Endpoints and design of clinical trials in patients with decompensated cirrhosis: Position paper of the LiverHope Consortium

Management of decompensated cirrhosis is currently geared towards the treatment of complications once they occur. To date there is no established disease-modifying therapy aimed at halting progression of the disease and preventing the development of complications in patients with decompensated cirrhosis. The design of clinical trials to investigate new therapies for patients with decompensated cirrhosis is complex. The population of patients with decompensated cirrhosis is heterogeneous (i.e., different etiologies, comorbidities and disease severity), leading to the inclusion of diverse populations in clinical trials. In addition, primary endpoints selected for trials that include patients with decompensated cirrhosis are not homogeneous and at times may not be appropriate. This leads to difficulties in comparing results obtained from different trials. Against this background, the LiverHope Consortium organized a meeting of experts, the goal of which was to develop recommendations for the design of clinical trials and to define appropriate endpoints, both for trials aimed at modifying the natural history and preventing progression of decompensated cirrhosis, as well as for trials aimed at managing the individual complications of cirrhosis.

Evolution of Liver Transplant Selection Criteria and U.S. Allocation Policy for Patients with Hepatocellular Carcinoma

Liver transplantation (LT) is an optimal treatment option for early-stage unresectable hepatocellular carcinoma (HCC) in patients with cirrhosis as it provides a treatment for underlying liver disease as well as a decreased incidence of recurrent cancer compared with alternative treatment strategies. A primary barrier to LT for HCC is the critical shortage of available liver allografts. The system of prioritization and access to deceased donor transplantation for patient with HCC in the United States has continued to evolve, while variable approaches including no additional priority, are in use around the world. While the Milan criteria remain the most well-established pretransplantation selection criteria, multiple other algorithms which expand beyond Milan have been proposed. The current review focuses on liver allocation for HCC as well as the principles and varied models available for pretransplant patient selection.