Outcomes for liver transplant candidates listed with low model for end-stage liver disease score

Future of U.S. living donor liver transplant: Donor and recipient criteria, transplant indications, transplant oncology, liver paired exchange, and non-directed donor graft allocation

In the United States, living donor liver transplant (LDLT), from both directed and nondirected living donors, has expanded over the past several years. LDLT is viewed as an important opportunity to expand the overall donor pool for liver transplantation (LT), shorten waiting times for a life-prolonging LT surgery, and reduce LT waitlist mortality. The LT community's focus on LDLT expansion in the United States is fostering discussions around future opportunities, which include the safe expansion of donor and recipient candidate eligibility criteria, broadening indications for LDLT including applications in transplant oncology, developing national initiatives around liver paired exchange, and maintaining vigilance to living donor and recipient candidate risk/benefit equipoise. Potential opportunities for expanding living liver donor and recipient candidate criteria include using donors with more than minimal hepatic steatosis, evaluating older donors, performing LDLT in older recipients to facilitate timely transplantation, and providing candidates who would benefit from an LT, but may otherwise have limited access (ie, lower MELD scores), an avenue to receive a life-prolonging organ. Expansion opportunities for LDLT are particularly robust in the transplant oncology realm, including leveraging LDLT for patients with advanced HCC beyond Milan, intrahepatic cholangiocarcinoma, and nonresectable colorectal cancer liver metastases. With ongoing investment in the deliberate growth of LDLT surgical expertise, experience, and technical advances in the United States, the LT community's future vision to increase transplant access to more patients with end-stage liver disease and selected oncology patients may be successfully realized.

Evaluating the Correlation Between Anteroposterior Diameter, Body Surface Area, and Height for Liver Transplant Donors and Recipients

Background

Small stature and female sex correlate to decreased deceased donor liver transplant (DDLT) access and higher waitlist mortality. However, efforts are being made to improve access and equity of allocation under the new continuous distribution (CD) system. Liver anteroposterior diameter (APD) is a method used by many centers to determine size compatibility for DDLT but is not recorded systematically, so it cannot be used for allocation algorithms. We therefore seek to correlate body surface area (BSA) and height to APD in donors and recipients and compare waitlist outcomes by these factors to support their use in the CD system.

Methods

APD was measured from single-center DDLT recipients and donors with cross-sectional imaging. Linear, Pearson, and PhiK correlation coefficient were used to correlate BSA and height to APD. Competing risk analysis of waitlist outcomes was performed using United Network for Organ Sharing data.

Results

For 143 pairs, donor BSA correlated better with APD than height (PhiK = 0.63 versus 0.20). For recipient all comers, neither BSA nor height were good correlates of APD, except in recipients without ascites, where BSA correlated well (PhiK = 0.63) but height did not. However, among female recipients, BSA, but not height, strongly correlated to APD regardless of ascites status (PhiK = 0.80 without, PhiK = 0.70 with). Among male recipients, BSA correlated to APD only in those without ascites (PhiK = 0.74). In multivariable models, both BSA and height were predictive of waitlist outcomes, with higher values being associated with increased access, decreased delisting for death/clinical deterioration, and decreased living donor transplant (model concordance 0.748 and 0.747, respectively).

Conclusions

Taken together, BSA is a good surrogate for APD and can therefore be used in allocation decision making in the upcoming CD era to offset size and gender-based disparities among certain candidate populations.

Transplant center variability in utilizing nonstandard donors and its impact on the transplantation of patients with lower MELD scores

There is a subset of patients with lower MELD scores who are at substantial risk of waitlist mortality. In order to transplant such patients, transplant centers must utilize "nonstandard" donors (eg, living donors, donation after circulatory death), which are traditionally offered to those patients who are not at the top of the waitlist. We used Organ Procurement and Transplantation data to evaluate center-level and region-level variability in the utilization of nonstandard donors and its impact on MELD at transplant among adult liver-alone non-status 1 patients transplanted from April 1, 2020, to September 30, 2022. The center-level variability in the utilization of nonstandard donors was 4-fold greater than the center-level variability in waitlisting practices (waitlistings with a MELD score of <20). While there was a moderate correlation between center-level waitlisting and transplantation of patients with a MELD score of <20 ( p = 0.58), there was a strong correlation between center-level utilization of nonstandard donors and center-level transplantation of patients with a MELD score of <20 ( p = 0.75). This strong correlation between center-level utilization of "nonstandard" donors and center-level transplantation of patients with a MELD score of <20 was limited to regions 2, 4, 5, 9, and 11. Transplant centers that utilize more nonstandard donors are more likely to successfully transplant patients at lower MELD scores. Public reporting of these data could benefit patients, caregivers, and referring providers, and be used to help maximize organ utilization.

3D auto-segmentation of biliary structure of living liver donors using magnetic resonance cholangiopancreatography for enhanced preoperative planning

BACKGROUND

This study aimed to develop an automated segmentation system for biliary structures using a deep learning model, based on data from magnetic resonance cholangiopancreatography (MRCP).

MATERIALS AND METHODS

Living liver donors who underwent MRCP using the gradient and spin echo technique followed by three-dimensional modeling were eligible for this study. A three-dimensional residual U-Net model was implemented for the deep learning process. Data were divided into training and test sets at a 9:1 ratio. Performance was assessed using the dice similarity coefficient to compare the model's segmentation with the manually labeled ground truth.

RESULTS

The study incorporated 250 cases. There was no difference in the baseline characteristics between the train set (n=225) and test set (n=25). The overall mean Dice Similarity Coefficient was 0.80±0.20 between the ground truth and inference result. The qualitative assessment of the model showed relatively high accuracy especially for the common bile duct (88%), common hepatic duct (92%), hilum (96%), right hepatic duct (100%), and left hepatic duct (96%), while the third-order branch of the right hepatic duct (18.2%) showed low accuracy.

CONCLUSION

The developed automated segmentation model for biliary structures, utilizing MRCP data and deep learning techniques, demonstrated robust performance and holds potential for further advancements in automation.

Trajectories of patients relisted for liver transplantation

INTRODUCTION AND OBJECTIVES

Recurrent cirrhosis complicates 10-30% of Liver transplants (LT) and can lead to consideration for re-transplantation. We evaluated the trajectories of relisted versus primary listed patients on the waitlist using a competing risk framework.

MATERIALS AND METHODS

We retrospectively examined 1,912 patients listed for LT at our centre between from 2012 to 2020. Cox proportional hazard models were used to assess overall survival (OS) by listing type and competing risk analysis Fine-Gray models were used to assess cumulative incidence of transplant by listing type.

RESULTS

1,731 patients were included (104 relisted). 44.2% of relisted patients received exception points vs. 19.8% of primary listed patients (p<0.001). Patients relisted without exceptions, representing those with graft cirrhosis, had the worst OS (HR: 4.17, 95%CI 2.63 - 6.67, p=<0.0001) and lowest instantaneous rate of transplant (HR: 0.56, 95%CI 0.38 - 0.83, p=0.006) than primary listed with exception points. On multivariate analysis listing type, height, bilirubin and INR were associated with cumulative incidence of transplant, while listing type, bilirubin, INR, sodium, creatinine were associated with OS. Within relisted patients, there was a trend towards higher mortality (HR: 1.79, 95%CI 0.91 - 3.52, p=0.08) and low transplant incidence (HR: 0.51, 95%CI 0.22 - 1.15, p=0.07) for graft cirrhosis vs other relisting indications.

CONCLUSIONS

Patients relisted for LT are carefully curated and comprise a minority of the waitlist population. Despite their younger age, they have worse liver/kidney function, poor waitlist survival, and decreased transplant incidence suggesting the need for early relisting, while considering standardized exception points.

Current Status of Living Donor Liver Transplantation: Impact, Advantages, and Challenges

PURPOSE OF THIS REVIEW

This review provides an overview of the current status of Living Donor Liver Transplant (LDLT). It discusses the impact of LDLT on waitlist and post-transplantation outcomes, highlighting the technical challenges and unique advantages of LDLT.

RECENT FINDINGS

Recent findings show that LDLT offers several theoretical advantages over deceased donor liver transplant, including shorter wait times, better graft quality, and improved post-transplant outcomes. Non-alcoholic fatty liver disease (NAFLD) and hepatocellular carcinoma (HCC) are emerging as the leading indications for adult LDLT in the US. LDLT demonstrates comparable or better overall survival rates and organ-specific outcomes compared to deceased donor transplants. However, challenges exist, including donor and recipient risks such as biliary complications and small-for-size syndrome. Ongoing research focuses on refining surgical techniques, exploring minimally invasive approaches, utilizing predetermined donors to modulate the recipient's immune system, and ensuring ethical practices. LDLT is a valuable solution for patients with end-stage liver failure or disorders requiring transplantation. It offers advantages such as shorter wait times as well as improved waitlist and post-transplant outcomes. Continued research and advancements in LDLT will benefit patients in need of liver transplantation.

Artificial intelligence, machine learning, and deep learning in liver transplantation

Liver transplantation (LT) is a life-saving treatment for individuals with end-stage liver disease. The management of LT recipients is complex, predominantly because of the need to consider demographic, clinical, laboratory, pathology, imaging, and omics data in the development of an appropriate treatment plan. Current methods to collate clinical information are susceptible to some degree of subjectivity; thus, clinical decision-making in LT could benefit from the data-driven approach offered by artificial intelligence (AI). Machine learning and deep learning could be applied in both the pre- and post-LT settings. Some examples of AI applications pre-transplant include optimising transplant candidacy decision-making and donor-recipient matching to reduce waitlist mortality and improve post-transplant outcomes. In the post-LT setting, AI could help guide the management of LT recipients, particularly by predicting patient and graft survival, along with identifying risk factors for disease recurrence and other associated complications. Although AI shows promise in medicine, there are limitations to its clinical deployment which include dataset imbalances for model training, data privacy issues, and a lack of available research practices to benchmark model performance in the real world. Overall, AI tools have the potential to enhance personalised clinical decision-making, especially in the context of liver transplant medicine.

Normothermic Machine Perfusion for Declined Livers: A Strategy to Rescue Marginal Livers for Transplantation

BACKGROUND

Organ waste is a major cause of the donor liver shortage. Roughly 67% of recovered organ donors have liver utilization annually. A new technology called normothermic machine perfusion (NMP) offers a way to recover marginal and declined livers for transplant. We report interim results of the RESTORE trial (FDA investigational drug exemption trial NCT04483102) that aims to transplant NMP-treated livers that would otherwise be discarded.

STUDY DESIGN

Declined livers were screened for NMP eligibility (eg donation after circulatory death [DCD] grafts with warm ischemic time <40 minutes, donation after brain death [DBD] grafts with cold ischemic time <8 hours). Livers meeting pre-NMP eligibility criteria received NMP using the OrganOx metra device for a minimum of 4 hours. All NMP-treated livers meeting the viability criteria were transplanted to consented recipients.

RESULTS

Over 22 months, 60 declined livers from three organ procurement organizations (OPOs; 40 DCD and 20 DBD donor livers) were offered, and 22 livers (10 DCD and 12 DBD livers) met the pre-NMP eligibility. After NMP, 16 of 22 livers passed viability testing and were transplanted into needy recipients (median Model for End-Stage Liver Disease [MELD] score of 8, range 6 to 24), resulting in a 72.7% rescue rate (50% DCD, 91.7% DBD). The rate of early allograft dysfunction was 31.3%, but there were no graft-related deaths, primary nonfunction, or instances of nonanastomotic biliary strictures.

CONCLUSIONS

Interim results of the RESTORE trial suggest that a sizable number of declined livers can be reclaimed. They are safe for transplantation and can enable lower MELD patients at high risk of morbidity and mortality to receive lifesaving grafts while offering OPOs a way to allocate more livers and reduce organ waste.

Is Liver Transplant Justified at Any MELD Score?

BACKGROUND

Assessing the survival benefit of transplantation in patients with end-stage liver disease is critical in guiding the decision-making process for liver allocation. Previous studies established increased mortality risk for those transplanted below Model for End-Stage Liver Disease (MELD) 18 compared with candidates who remained on the waitlist; however, improved outcomes of liver transplantation and a changing landscape in the donor supply warrant re-evaluation of this idea.

METHODS

Using the United Network for Organ Sharing database, we analyzed 160 290 candidates who were waitlisted for liver transplantation within MELD cohorts. We compared patients who were transplanted in a MELD cohort with those listed but not transplanted in that listed MELD cohort with an intent-to-treat analysis.

RESULTS

Those transplanted at a MELD between 6 and 11 showed a 31% reduction in adjusted mortality (HR = 0.69 [95% confidence interval [CI], 0.66-0.75]; P < 0.001) compared with the intent-to-treat cohort in a Cox multivariate regression. This mortality benefit increased to a 37% adjusted reduction for those transplanted at MELD between 12 and 14 (HR = 0.63 [95% CI, 0.60-0.66]; P < 0.001) and a 46% adjusted reduction for those transplanted at a MELD between 15 and 17 (HR = 0.54 [95% CI, 0.52-0.57]; P < 0.001), effects that remained in sensitivity analyses excluding patients with hepatocellular carcinoma, encephalopathy, ascites, and variceal bleeds. A multivariate analysis of patients transplanted at MELD < 18 found younger age and cold ischemia time were protective, whereas older age, lower functional status, and socioeconomic factors increased mortality risk.

CONCLUSIONS

These findings challenge the current practice of deferring liver transplants below a particular MELD score by demonstrating survival benefits for most transplant patients at the lowest MELD scores and providing insight into who benefits within these subgroups.

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.

Are MELD and MELDNa Still Reliable Tools to Predict Mortality on the Liver Transplant Waiting List?

Liver transplantation is the only curative treatment for end-stage liver disease. Unfortunately, the scarcity of donor organs and the increasing pool of potential recipients limit access to this life-saving procedure. Allocation should account for medical and ethical factors, ensuring equal access to transplantation regardless of recipient's gender, race, religion, or income. Based on their short-term prognosis prediction, model for end-stage liver disease (MELD) and MELD sodium (MELDNa) have been widely used to prioritize patients on the waiting list for liver transplantation resulting in a significant decrease in waiting list mortality/removal. Recent concern has been raised regarding the prognostic accuracy of MELD and MELDNa due, in part, to changes in recipients' profile such as body mass index, comorbidities, and general condition, including nutritional status and cause of liver disease, among others. This review aims to provide a comprehensive view of the current state of MELD and MELDNa advantages and limitations and promising alternatives. Finally, it will explore future options to increase the donor pool and improve donor-recipient matching.

Prognostic value of neutrophil-to-lymphocyte ratio in cirrhosis patients undergoing transjugular intrahepatic portosystemic shunt

BACKGROUND AND AIMS

The neutrophil-to-lymphocyte-ratio (NLR) is used as an inflammatory index and has proven to be an accurate prognostic indicator for decompensated cirrhotics; however, its role in patients undergoing transjugular intrahepatic portosystemic shunt (TIPS) has not been evaluated. We examined whether NLR is associated with mortality in decompensated cirrhosis patients undergoing TIPS.

METHODS

We performed a retrospective review of 268 decompensated cirrhotics who underwent TIPS from January 2011 to December 2015 at an academic medical center. NLR, patient demographics, manifestations of cirrhosis, TIPS indications and mortality were recorded. Univariate and multivariate Cox regression analyses for prognostic factors associated with 30-day and 90-day post TIPS mortality were performed.

RESULTS

A total of 129 (48%) patients received TIPS for refractory ascites with 79 (29%) for variceal bleeding, 14 (5%) for hepatic hydrothorax, and 46 (17%) for other indications. Cirrhosis etiology included hepatitis C (36%), alcohol (28%), nonalcoholic steatohepatitis (20%), or other (15%). Median NLR was 4.42 (IQR 2.75-7.19). Univariate and multivariate analysis showed NLR as an independent predictive factor of 30-day and 90-day mortality. Furthermore, in patients with a Model of End-Stage Liver Disease (MELD) ≤ 15, NLR is superior to MELD/MELD-Na score in predicting 30-day and 90-day mortality. In patients with MELD > 15, MELD/MELD-Na score is superior to NLR.

CONCLUSION

Our data indicate that elevated NLR independently predicts 30-day and 90-day mortality. In patients with a MELD ≤ 15, NLR is a better prognostic factor than MELD or MELD-Na in predicting short-term mortality.

Healthcare Resource Utilization After Living Liver Donation: A Retrospective Case-control Study

BACKGROUND

Living liver donation is generally considered safe, but donors may experience short or long-term complications. The purpose of this study was to assess healthcare resource utilization after liver donation in living liver donors in comparison to the general population.

METHODS

Outpatient or emergency department visits and hospital admissions were compared between living liver donors who underwent hepatic resection for living liver donation between 2004 and 2018 and the matched general population. Healthcare resource utilization data for 5 years after liver donation were collected from the National Health Insurance Service (NHIS) database. For every living liver donor, 4 individually matched nondonors were selected from the NHIS database using age, sex, preexisting comorbidities, and previous healthcare utilization history.

RESULTS

A total of 1886 living liver donors and 7309 nondonors were included. In the first year after donation, living liver donors required more outpatient department visits (7 [4-13] vs. 3 [1-7], P < 0.001) and more emergency department visits (13.33% vs. 0.15%, P < 0.001) compared to matched nondonors. A similar trend persisted for 5 years after donation. The number of hospital admissions of living liver donors was higher for up to 2 years after donation with longer hospital length of stay (13.0 [10.5-16.0] vs. 5.0 [3.0-9.0] days, P < 0.0001).

CONCLUSIONS

Healthcare resource utilization in living liver donors for 5 years after donation were higher compared to matched nondonors. The higher healthcare resource demand may be related to postoperative complications or lowered threshold for healthcare resource utilization after donation.Supplemental Visual Abstract; http://links.lww.com/TP/C291.

Black Patients With Cirrhosis Have Higher Mortality and Lower Transplant Rates: Results From a Metropolitan Cohort Study

BACKGROUND AND AIMS

Estimates of racial disparity in cirrhosis have been limited by lack of large-scale, longitudinal data, which track patients from diagnosis to death and/or transplant.

APPROACH AND RESULTS

We analyzed a large, metropolitan, population-based electronic health record data set from seven large health systems linked to the state death registry and the national transplant database. Multivariate competing risk analyses, adjusted for sex, age, insurance status, Elixhauser score, etiology of cirrhosis, HCC, portal hypertensive complication, and Model for End-Stage Liver Disease-Sodium (MELD-Na), examined the relationship between race, transplant, and cause of death as defined by blinded death certificate review. During the study period, 11,277 patients met inclusion criteria, of whom 2,498 (22.2%) identified as Black. Compared to White patients, Black patients had similar age, sex, MELD-Na, and proportion of alcohol-associated liver disease, but higher comorbidity burden, lower rates of private insurance, and lower rates of portal hypertensive complications. Compared to White patients, Black patients had the highest rate all-cause mortality and non-liver-related death and were less likely to be listed or transplanted (P < 0.001 for all). In multivariate competing risk analysis, Black patients had a 26% increased hazard of liver-related death (subdistribution HR, 1.26; 95% CI, [1.15-1.38]; P < 0.001).

CONCLUSIONS

Black patients with cirrhosis have discordant outcomes. Further research is needed to determine how to address these real disparities in the field of hepatology.

Pre and post-liver transplant outcome of cirrhotic patients with acute on chronic liver failure

Acute on chronic liver failure (ACLF) is a dynamic syndrome, but frequently associated with a high 1 month mortality rate. This is the first study applying the new European Association for the Study of the Liver- chronic liver failure consortium criteria to explore mortality on the waiting list (WL) and early after liver transplantation (LT) in a cohort of Romanian cirrhotic patients that improved or recovered after an episode of ACLF.To assess frequency and waitlist mortality for different grades of ACLF.An observational study was conducted; 257 patients with liver cirrhosis included on the WL between 2015 and 2017 were analyzed. The cumulative incidence of waitlist mortality or removal was calculated for combination of competing events using multivariable competing risks regression.ACLF-1 occurred in 12.07%, ACLF-2 in 7.39% and ACLF-3 in 8.56% of patients. Median Model for End Stage Liver Diseases (MELD) score at the moment of ACLF was 29. The main event while on the WL was death, followed by ACLF; patients with ACLF-3 had a significantly greater subhazard ratio for mortality of 2.25 (1.55-3.26) compared to patients with ACLF-1 or 2. LT proved to be associated with a significantly lower risk of death on the WL at 6 months after inclusion. One and 12 months post-transplant survival of patients with or without ACLF was similar (P = .77).Occurrence of an ACLF episode while on the WL is associated with a significantly high mortality rate, as well as MELD score at inclusion on the WL, renal and liver failure, presence of hepatic encephalopathy. Overall patient short and long term survival after LT is similar to non-ACLF patients in good selected cases.

Application of Hepatic Venous Pressure Gradient to Predict Prognosis in Cirrhotic Patients with a Low Model for End-Stage Liver Disease Score

Background/aim: We aimed to derive a model representing the dynamic status of cirrhosis and to discriminate patients with poor prognosis even if the Model for End-Stage Liver Disease (MELD) score is low. Methods: This study retrospectively enrolled 700 cirrhotic patients with a MELD score of less than 20 who underwent hepatic venous pressure gradient (HVPG) measurement. A model named H6C score (= HVPG + 6 × CTP score) to predict overall survival was derived and internal and external validations were conducted with the derivation and validation cohorts. Results: The H6C score using the HVPG was developed based on a multivariate Cox regression analysis. The H6C score showed a great predictive power for overall survival with a time-dependent AUC of 0.733, which was superior to that of a MELD of 0.602. In patients with viral etiology, the performance of the H6C score was much improved with a time-dependent AUC of 0.850 and was consistently superior to that of the MELD (0.748). Patients with an H6C score below 45 demonstrated an excellent overall survival with a 5-year survival rate of 91.5%. Whereas, patients with an H6C score above 64 showed a dismal prognosis with a 5-year survival rate of 51.1%. The performance of the H6C score was further verified to be excellent in the validation cohort. Conclusion: This new model using the HVPG provides an excellent predictive power in cirrhotic patients, especially with viral etiology. In patients with H6C above 64, it would be wise to consider early liver transplantation to positively impact long-term survival, even when the MELD score is low.

A Comprehensive Review of Outcome Predictors in Low MELD Patients

Risk scoring for patients with cirrhosis has evolved greatly over the past several decades. However, patients with low Model for End-Stage Liver Disease-Sodium scores still suffer from liver-related morbidity and mortality. Unfortunately, it is not clear which of these low Model for End-Stage Liver Disease-Sodium score patients would benefit from earlier consideration of liver transplantation. This article reviews the literature of risk prediction in patients with cirrhosis, identifies which patients may benefit from earlier interventions, such as transplantation, and proposes directions for future research.

Patients With Persistently Low MELD-Na Scores Continue to Be at Risk of Liver-related Death

BACKGROUND

The vast majority of patients with cirrhosis have low Model for End-Stage Liver Disease-Sodium (MELD-Na) scores; however, the ability for the MELD-Na score to predict patient outcomes at low scores is unclear.

METHODS

Adult patients in a multicenter, Chicago-wide database of medical records with International Classification of Disease, Ninth Edition codes of cirrhosis and without a history of hepatocellular carcinoma were included. Records were linked with the state death registry, and death certificates were manually reviewed. Deaths were classified as "liver-related," "non-liver-related," and "non-descript" as adjudicated by a panel comprised of a transplant surgeon, a hepatologist, and an internist. A sensitivity analysis was performed where patients with hepatocellular carcinoma were included.

RESULTS

Among 7922 identified patients, 3999 patients had MELD-Na scores that were never higher than 15. In total, 2137 (27%) patients died during the study period with higher mortality rates for the patients in the high MELD-Na group (19.4 (41.6%) versus 4.1 (12.6%) per 100 person-y, P < 0.001). The high MELD-Na group died of a liver-related cause in 1142 out of 1632 (70%) as compared to 240 out of 505 (47.5%) deaths in the low MELD-Na group. There was no difference in the distribution of subcategory of liver-related death between low and high MELD-Na groups. Among subclassification of liver-related deaths, the most common cause of death was "Infectious" in both groups.

CONCLUSIONS

Despite persistently low MELD-Na scores, patients with cirrhosis still experience high rates of liver-related mortality.

Pathologic response translates to improved patient survival after locoregional treatment for hepatocellular carcinoma: the importance of minimally invasive microwave ablation

BACKGROUND

Hepatectomy or transplantation can serve as curative treatment for early-stage hepatocellular carcinoma (HCC). Unfortunately, as progression remains a reality, locoregional therapies (LRT) for curative or bridging intent have become common. Efficacy on viability, outcomes, and accuracy of imaging should be defined to guide treatment.

METHODS

Patients with HCC who underwent minimally invasive (MIS) microwave ablation (MWA), transarterial chemoembolization (TACE), or both (MIS-MWA-TACE) prior to hepatectomy or transplantation were identified. Tumor response and preoperative computed tomography (CT) accuracy were assessed and compared to pathology. Clinical and oncologic outcomes were compared between MIS-MWA, TACE, and MIS-MWA-TACE.

RESULTS

Ninety-one patients, with tumors from all stages of the Barcelona Clinic Liver Cancer (BCLC) staging, were identified who underwent LRT prior to resection or transplant. Fourteen patients underwent MIS-MWA, 46 underwent TACE, and 31 underwent both neoadjuvantly. TACE population was older; otherwise, there were no differences in demographics. Fifty-seven percent of MIS-MWA patients had no viable tumor on pathology whereas only 13% of TACE patients and 29% of MIS-MWA-TACE patients had complete destruction (p = 0.004). The amount of remaining viable tumor in the explant was also significantly different between groups (MIS-MWA: 17.2%, TACE: 48.7%, MIS-MWA-TACE: 18.6%; p ≤ 0.0001). Compared with TACE, the MIS-MWA and MIS-MWA-TACE groups had significantly improved overall survival (MIS-MWA: 99.94 months, TACE: 75.35 months, MIS-MWA-TACE: 140 months; p = 0.017). This survival remained significant with stratification by tumor size. CT accuracy was found to be 50% sensitive and 86% specific for MIS-MWA. For TACE, CT had an 82% sensitivity and 33% specificity and for MIS-MWA-TACE, there was a 42% sensitivity and 78% specificity.

CONCLUSION

The impact of locoregional treatments on tumor viability is distinct and superior with MIS-MWA alone and MIS-MWA-TACE offering significant advantage over TACE alone. The extent of this effect may be implicated in the improved overall survival.

Liver transplantation and cardiac illness: Current evidences and future directions

Contraindications to liver transplantation are gradually narrowing. Cardiac illness and chronic liver disease may manifest independently or may be superimposed on each other due to shared pathophysiology. Cardiac surgery involving the cardiopulmonary bypass in patients with Child-Pugh Class C liver disease is associated with a high risk of perioperative morbidity and mortality. Liver transplantation involves hemodynamic perturbations, volume shifts, coagulation abnormalities, electrolyte disturbances, and hypothermia, which may prove fatal in patients with cardiac illness depending upon the severity. Additionally, cardiovascular complications are the major cause of adverse postoperative outcomes after liver transplantation even in the absence of cardiac pathologies. Clinical decision-making has remained an unsettled issue in these clinical scenarios. The absence of randomized clinical studies has further crippled our endeavours for a consensus on the management of patients with end-stage liver disease with cardiac illness. This review seeks to address this complex clinical setting by gathering information from published literature. The management algorithm in this review may facilitate clinical decision making and augur future research.

Including body composition in MELD scores improves mortality prediction among patients awaiting liver transplantation

BACKGROUND & AIMS

The Model for End-stage Liver Diseases (MELD) is widely accepted for prioritizing candidates awaiting liver transplantation (LT). However, MELD scores do not reflect the severity of the nutritional or functional status of patients with cirrhosis.

METHODS

This retrospective study analyzed data from 173 patients who were waitlisted for LT at our institution between April 2006 and December 2016. By including skeletal muscle mass, muscle quality and visceral adiposity evaluated using plain computed tomography imaging in MELD scores, we developed body composition-MELD (BC-MELD), and investigated its impact on the prediction of mortality among patients awaiting LT.

RESULTS

The equation generated using Cox regression analysis was as follows: BC-MELD = MELD score + 3.59 × low SMI + 5.42 × high IMAC + 2.06 × high VSR. (IMAC, intramuscular adipose tissue content; SMI, skeletal muscle mass index; VSR, visceral-to-subcutaneous adipose tissue area ratio). The median BC-MELD score was 17.4 and the area under the receiver operating characteristic curve (AUC) revealed a cut-off BC-MELD score of 21.4 (AUC = 0.835, P < 0.001, sensitivity 87.5%, specificity 70.7%). Waitlist mortality in patients with high BC-MELD was significantly higher in all tested cohorts (P < 0.001) and among patients with lower conventional MELD scores (<15) (P < 0.001). The discriminatory power was significantly better for BC-MELD than MELD scores (AUC; 0.835 vs. 0.732, P = 0.001 for 3-month, AUC; 0.765 vs. 0.671, P = 0.002 for 6-month, AUC; 0.716 vs. 0.615, P < 0.001 for 12-month, AUC; 0.636 vs. 0.584, P = 0.014 for overall mortality).

CONCLUSIONS

BC-MELD is the first to include not only muscularity but also visceral adiposity. It predicted waitlist mortality more accurately than the conventional MELD score. A new allocation system based on BC-MELD might lead to better outcomes for patients with cirrhosis awaiting LT.

Waiting List Mortality and Transplant Rates for NASH Cirrhosis When Compared With Cryptogenic, Alcoholic, or AIH Cirrhosis

BACKGROUND

Patients with nonalcoholic steatohepatitis (NASH) cirrhosis have excellent postliver transplant survival despite having many comorbidities. We hypothesized that this could be due to a selection bias.

METHODS

We analyzed the United Network for Organ Sharing data from 2002 to 2016 and compared postliver transplant survival of NASH (n = 7935) patients with cryptogenic cirrhosis (CC) (n = 6087), alcoholic cirrhosis (AC) (n = 16 810), and autoimmune hepatitis cirrhosis (AIH) (n = 2734).

RESULTS

By 3 years of listing, the cumulative incidence (CI) of death or deterioration was 29% for NASH, 28% for CC and AC, and 24% for AIH, but when adjusted for risk factors, the CI was similar for NASH and AIH. The factors that increased the risk of waiting list removal due to death/deterioration were poor performance status, encephalopathy, diabetes, high Model for End-stage Liver Disease, Hispanic race, older age and a low serum albumin. Most patients were transplanted within the first year (median, 2 months; interquartile range, 1-7 months) of listing and by 5 years, the unadjusted CI of transplantation was 54% for NASH, 52% for CC, 51% for AIH, and 48% for AC. The adjusted CI of transplantation within 2 months of listing was higher for AC (subhazard ratio [SHR], 1.17), AIH (SHR, 1.17), and CC (SHR, 1.13) when compared with NASH, but after 2 months, adjusted transplantation rates decreased in AC (SHR, 0.6), AIH (SHR, 0.78), and CC (SHR, 0.95). The negative predictors of receiving a transplant were dialysis, female sex, nonwhite race, high albumin, and creatinine.

CONCLUSIONS

Patients with NASH cirrhosis are not disadvantaged by higher waitlist removal or lower transplantation rates.

Nonalcoholic steatohepatitis: the new frontier for liver transplantation

PURPOSE OF REVIEW

Nonalcoholic fatty liver disease (NAFLD) is a growing cause of chronic liver disease globally and nonalcoholic steatohepatitis is projected to become the most common indication for liver transplantation. The purpose of this review is to highlight key issues surrounding NAFLD as an indication for liver transplantation, including its increasing prevalence, outcomes related to liver transplantation, development of post liver transplant NAFLD and NAFLD in the liver donor pool.

RECENT FINDINGS

With the advent of direct-acting antiviral therapies, the proportion of patients on the liver transplant list or undergoing liver transplant for chronic hepatitis C infection is steadily decreasing. In contrast, the number transplants performed for NAFLD is increasing. By 2030, it is estimated that the incidence of decompensated cirrhosis and hepatocellular carcinoma will increase by 168 and 137%, respectively, and the number of deaths will increase by 178%.

SUMMARY

Liver transplantation cures cirrhosis but does not treat the underlying metabolic disease associated with NAFLD. Thus, strategies to control comorbidities in patients with NAFLD prior to transplant are needed to decrease waitlist mortality and the recurrence of NAFLD after liver transplant. NAFLD in the donor pool is also a growing concern. Strategies to minimize steatosis and expand the number of donors are critical to meet the growing demand for liver transplantation.

Successful Liver Transplantation Case Report from a Deceased Donor with Sickle Cell Anemia

There is a worldwide problem of waiting time and mortality rate associated with remaining on the waiting list for a liver transplant. However, some situations have been encouraging in terms of determining appropriate recipients and expanding the donor criteria. We herein report a case of useful liver donor with sickle cell anemia for liver transplantation. Here we described a case of liver transplantation from a donor with sickle cell anemia to a recipient with hepatocellular carcinoma who was deemed to be at risk of tumor growth and at risk of being dropped from the waiting list. The literature reveals the importance of using safe donors, and we describe the benefits of using a safe, deceased liver donor with sickle cell anemia who was an adequate option for liver transplantation.

Accuracy of the Pediatric End-stage Liver Disease Score in Estimating Pretransplant Mortality Among Pediatric Liver Transplant Candidates

IMPORTANCE

Fair allocation of livers between pediatric and adult recipients is critically dependent on the accuracy of mortality estimates afforded by the Pediatric End-stage Liver Disease (PELD) and Model for End-stage Liver Disease, respectively. Widespread reliance on exceptions for pediatric recipients suggests that the 2 systems may not be comparable.

OBJECTIVE

To evaluate the accuracy of the PELD score in estimating 90-day pretransplant mortality among pediatric patients on the United Network for Organ Sharing (UNOS) waiting list.

DESIGN, SETTING, AND PARTICIPANTS

Patients who were listed from February 27, 2002, to March 31, 2014, for primary liver transplant were included in this retrospective analysis and were followed up for at least 2 years through June 17, 2016. The study analyzed 2 cohorts using the UNOS Standard Transplant Analysis and Research data files. The full cohort comprised 4298 patients (<18 years of age) who had chronic liver disease (excluding cancer). The reduced cohort (n = 2421) excluded patients receiving living donor transplantation or PELD exception points.

MAIN OUTCOMES AND MEASURES

Observed and expected 90-day pretransplant mortality rates evaluated at 10-point interval PELD levels.

RESULTS

Among the 4298 patients in the full cohort (mean [SD] age, 2.5 [4.2] years; 2251 [52.4%] female; 2201 [51.2%] white), PELD scores and mortality were concordant (C statistic, 0.8387 [95% CI, 0.8191-0.8584] for the full cohort and 0.8123 [95% CI, 0.7919-0.8327] for the reduced cohort). However, the estimated 90-day mortality using the PELD score underestimated the actual probability of death by as much as 17%.

CONCLUSIONS AND RELEVANCE

With use of the PELD score, the ranking of risk among children was preserved, but direct comparisons between adult and pediatric candidates were not accurate. Children with chronic liver disease who are in need of transplant may be at a disadvantage compared with adults in a similar situation.

Recipient characteristics and morbidity and mortality after liver transplantation

BACKGROUND AND AIMS

Over the last decade, liver transplantation of sicker, older non-hepatitis C cirrhotics with multiple co-morbidities has increased in the United States. We sought to identify an easily applicable set of recipient factors among HCV negative adult transplant recipients associated with significant morbidity and mortality within five years after liver transplantation.

METHODS

We collected national (n = 31,829, 2002-2015) and center-specific data. Coefficients of relevant recipient factors were converted to weighted points and scaled from 0-5. Recipient factors associated with graft failure included: ventilator support (five patients; hazard ratio [HR] 1.59; 95% CI 1.48-1.72); recipient age >60 years (three patients; HR 1.29; 95% CI 1.23-1.36); hemodialysis (three patients; HR 1.26; 95% CI 1.16-1.37); diabetes (two patients; HR 1.20; 95% CI 1.14-1.27); or serum creatinine ≥1.5 mg/dl without hemodialysis (two patients; HR 1.15; 95% CI 1.09-1.22).

RESULTS

Graft survival within five years based on points (any combination) was 77.2% (0-4), 69.1% (5-8) and 57.9% (>8). In recipients with >8 points, graft survival was 42% (model for end-stage liver disease [MELD] score <25) and 50% (MELD score 25-35) in recipients receiving grafts from donors with a donor risk index >1.7. In center-specific data within the first year, subjects with ≥5 points (vs. 0-4) had longer hospitalization (11 vs. 8 days, p <0.01), higher admissions for rehabilitation (12.3% vs. 2.7%, p <0.01), and higher incidence of cardiac disease (14.2% vs. 5.3%, p <0.01) and stage 3 chronic kidney disease (78.6% vs. 39.5%, p = 0.03) within five years.

CONCLUSION

The impact of co-morbidities in an MELD-based organ allocation system need to be reassessed. The proposed clinical tool may be helpful for center-specific assessment of risk of graft failure in non-HCV patients and for discussion regarding relevant morbidity in selected subsets.

LAY SUMMARY

Over the last decade, liver transplantation of sicker, older patient with multiple co-morbidities has increased. In this study, we show that a set of recipient factors (recipient age >60 years, ventilator status, diabetes, hemodialysis and creatinine >1.5 mg/dl) can help identify patients that may not do well after transplant. Transplanting sicker organs in patients with certain combinations of these characteristics leads to lower survival.

The New Era of Transplant Oncology: Liver Transplantation for Nonresectable Colorectal Cancer Liver Metastases

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

Selection of Patients for Initial Clinical Trials of Solid Organ Xenotransplantation

Several groups have reported extended survival of genetically engineered pig organs in nonhuman primates, varying from almost 10 months for life-supporting kidney grafts and more than 2 years for non-life-supporting heart grafts to less than 1 month for life-supporting liver and lung grafts. We have attempted to define groups of patients who may not have an option to wait for an allograft. These include kidney, heart, and lung candidates who are highly-allosensitized. In addition, some kidney candidates (who have previously lost at least 2 allografts from rapid recurrence of native kidney disease) have a high risk of further recurrence and will not be offered a repeat allotransplant. Patients with complex congenital heart disease, who may have undergone previous palliative surgical procedures, may be unsuitable for ventricular assist device implantation. Patients dying of fulminant hepatic failure, for whom no alternative therapy is available, may be candidates for a pig liver, even if only as a bridge until an allograft becomes available. When the results of pig organ xenotransplantation in nonhuman primates suggest a realistic potential for success of a pilot clinical trial, highly selected patients should be offered participation.

Neutrophil-to-lymphocyte ratio correlates with proinflammatory neutrophils and predicts death in low model for end-stage liver disease patients with cirrhosis

The Model for End-Stage Liver Disease (MELD) score has reduced accuracy for liver transplantation (LT) wait-list mortality when MELD ≤ 20. Neutrophil-to-lymphocyte ratio (NLR) is a biomarker associated with systemic inflammation and may predict cirrhotic decompensation and death. We aimed to evaluate the prognostic utility of high NLR (≥4) for liver-related death among low MELD patients listed for LT, controlling for stage of cirrhosis. In a nested case-control study of cirrhotic adults awaiting LT (February 2002 to May 2011), cases were LT candidates with a liver-related death and MELD ≤ 20 within 90 days of death. Controls were similar LT candidates who were alive for ≥90 days after LT listing. NLR and other covariates were assessed at the date of lowest MELD, within 90 days of death for cases and within 90 days after listing for controls. There were 41 cases and 66 controls; MELD scores were similar. NLR 25th, 50th, 75th percentile cutoffs were 1.9, 3.1, and 6.8. NLR was ≥ 4 in 25/41 (61%) cases and in 17/66 (26%) controls. In univariate analysis, NLR (continuous ≥ 1.9, ≥ 4, ≥ 6.8), increasing cirrhosis stage, jaundice, encephalopathy, serum sodium, and albumin and nonselective beta-blocker use were significantly (P < 0.01) associated with liver-related death. In multivariate analysis, NLR of ≥1.9, ≥ 4, ≥ 6.8 were each associated with liver-related death. Furthermore, we found that NLR correlated with the frequency of circulating low-density granulocytes, previously identified as displaying proinflammatory properties, as well as monocytes. In conclusion, elevated NLR is associated with liver-related death, independent of MELD and cirrhosis stage. High NLR may aid in determining risk for cirrhotic decompensation, need for increased monitoring, and urgency for expedited LT in candidates with low MELD. Liver Transplantation 23 155-165 2017 AASLD.

Graft Reconditioning before Liver Transplantation

BACKGROUND

The high demand for livers for transplantation has led to organs of limited quality being accepted to expand the donor pool. This is associated with inferior outcomes due to more pronounced preservation injury. Accordingly, recent research has aimed to develop preservation modalities for improved preservation as well as strategies for liver viability assessment and liver reconditioning.

METHODS

The PubMed database was searched using the terms 'perfusion', 'liver', 'preservation', and 'reconditioning' in various combinations, and the according literature was reviewed.

RESULTS

Several perfusion techniques have been developed in recent years with the potential for liver reconditioning. Preclinical and first emerging clinical data suggest feasibility, safety, and superiority over the current gold standard of cold storage.

CONCLUSION

This review outlines current advances in the field of liver preservation with an emphasis on liver reconditioning methods.

Nonalcoholic Fatty Liver Disease: Key Considerations Before and After Liver Transplantation

Nonalcoholic fatty liver disease (NAFLD) is the most common etiology of chronic liver disease in developed countries and is on trajectory to become the leading indication for liver transplantation in the USA and much of the world. Patients with NAFLD cirrhosis awaiting liver transplant face unique challenges and increased risk for waiting list stagnation and dropout due to burdensome comorbidities including obesity, diabetes, cardiovascular disease, and kidney disease. Thus far, patients transplanted for NAFLD cirrhosis have excellent mid- and long-term patient and graft survival, but concerns regarding short-term morbidity and mortality continue to exist. Post-liver transplantation, NAFLD occurs as both a recurrent and de novo manifestation, each with unique outcomes. NAFLD in the donor population is of concern given the growing demand for liver transplantation and mounting pressure to expand the donor pool. This review addresses key issues surrounding NAFLD as an indication for transplantation, including its increasing prevalence, unique patient demographics, outcomes related to liver transplantation, development of post-liver transplantation NAFLD, and NAFLD in the liver donor population. It also highlights exciting areas where further research is needed, such as the role of bariatric surgery and preconditioning of marginal donor grafts.