Standardizing MELD Exceptions: Current Challenges and Future Directions

[The Role of the Anaesthesiologist in Liver Transplantation - Preoperative Evaluation]

Preoperative evaluation prior to listing for orthotopic liver transplantation (LT) requires a careful multidisciplinary approach with specialized teams including surgeons, hepatologists and anesthesiologists in order to improve short- and long-term clinical outcomes. Due to inadequate supply of donor organs and changing demographics, patients listed for LT have become older, sicker and share more comorbidities. As cardiovascular events are the leading cause for early mortality precise evaluation of risk factors is mandatory. This review focuses on the detection and management of coronary artery disease, cirrhotic cardiomyopathy, portopulmonary hypertension and hepatopulmonary syndrome in patients awaiting LT. Further insights are being given into scoring systems, patients with Acute-on-chronic-liver-failure (ACLF), frailty, NASH cirrhosis and into psychologic evaluation of patients with substance abuse.

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.

Liver Transplantation for Primary Sclerosing Cholangitis (PSC) With or Without Inflammatory Bowel Disease (IBD)-A European Society of Organ Transplantation (ESOT) Consensus Statement

Primary sclerosing cholangitis (PSC) is the classical hepatobiliary manifestation of inflammatory bowel disease (IBD) and a lead indication for liver transplantation (LT) in the western world. In this article, we present a Consensus Statement on LT practice, developed by a dedicated Guidelines' Taskforce of the European Society of Organ Transplantation (ESOT). The overarching goal is to provide practical guidance on commonly debated topics, including indications and timing of LT, management of bile duct stenosis in patients on the transplant waiting list, technical aspects of transplantation, immunosuppressive strategies post-transplant, timing and extension of intestinal resection and futility criteria for re-transplantation.

Exception points for liver transplantation: A Canadian review

Background

Exception points for liver transplant (LT) allocation are used to account for mortality risk not reflected by scoring systems such as the Model for End-Stage Liver Disease with sodium (MELD-Na). Currently, there is no formal policy regarding exception points in Canada, and differences across the country are not well understood. As such, a review of the criteria and exception points granted throughout the country for LT was conducted.

Methods

Seven LT centres in five provinces were surveyed (Vancouver, Edmonton, London, Toronto, Montréal, Halifax) regarding the indications and criteria for exception points granted, the number of points granted, how points would be accrued, and the maximum points granted.

Results

Programs in British Columbia and Nova Scotia grant variable exception points based on the median MELD-Na score with modifications; Alberta, Ontario, and Quebec grant exception points using specific values based on the indication. Overall, there was significant heterogeneity regarding exception points granted nationally with agreement only for awarding exception points for hepatopulmonary syndrome and polycystic liver disease. The second most common agreed-upon indications for exception points were portopulmonary hypertension and recurrent cholangitis offered by four provinces. Quebec had the most formal criteria for non-cirrhosis-based conditions.

Conclusions

There is substantial variance across the country regarding the indications for granting exception points as well as the number of points granted. Future work on developing a national consensus will be important for the development of equity in LT across Canada.

Liver Transplant in Patients with Hepatocarcinoma: Imaging Guidelines and Future Perspectives Using Artificial Intelligence

Hepatocellular carcinoma is the most common primary malignant hepatic tumor and occurs most often in the setting of chronic liver disease. Liver transplantation is a curative treatment option and is an ideal solution because it solves the chronic underlying liver disorder while removing the malignant lesion. However, due to organ shortages, this treatment can only be applied to carefully selected patients according to clinical guidelines. Artificial intelligence is an emerging technology with multiple applications in medicine with a predilection for domains that work with medical imaging, like radiology. With the help of these technologies, laborious tasks can be automated, and new lesion imaging criteria can be developed based on pixel-level analysis. Our objectives are to review the developing AI applications that could be implemented to better stratify liver transplant candidates. The papers analysed applied AI for liver segmentation, evaluation of steatosis, sarcopenia assessment, lesion detection, segmentation, and characterization. A liver transplant is an optimal treatment for patients with hepatocellular carcinoma in the setting of chronic liver disease. Furthermore, AI could provide solutions for improving the management of liver transplant candidates to improve survival.

Updates on the Model for End-Stage Liver Disease Score and Impact on the Liver Transplant Waiting List: A Narrative Review

The model for end-stage liver disease (MELD) score is an established indicator of cirrhosis severity and a predictor of morbidity and mortality in patients undergoing transjugular intrahepatic portosystemic shunt (TIPS) creation and for allocation in liver transplantation. Since the adoption of the score, its use has been expanded to multiple new indications requiring model modifications, including relevant clinical and demographic variables, to increase predictive accuracy. The purpose of this report is to provide an update on the modifications made to the MELD score, comparing their performance with C statistics, advantages and disadvantages, and impact on mortality at 3 months after placing a TIPS or awaiting liver transplantation.

Model for End-Stage Liver Disease/Pediatric End-Stage Liver Disease exception policy and outcomes in pediatric patients with hepatopulmonary syndrome requiring liver transplantation

Hepatopulmonary syndrome (HPS) is associated with increased waitlist mortality in liver transplantation (LT) candidates. Children with HPS are granted Model for End-Stage Liver Disease (MELD)/Pediatric End-Stage Liver Disease (PELD) exception points for waitlist prioritization in the United States based on criterion developed for adults. In this study, the impact of this MELD/PELD exception policy on post-LT survival in children was examined. A retrospective cohort of patients aged younger than 18 years with a MELD/PELD exception request who underwent LT between 2007 and 2018 were identified in the Scientific Registry of Transplant Recipients. Patients were stratified by waitlist partial pressure of arterial oxygen (PaO 2 ) to assess risk factors for waitlist mortality and post-LT survival. Among 3082 pediatric LT recipients included in the study, 124 patients (4%) received MELD/PELD exception points for HPS. Patients with HPS were a median age of 9 years (interquartile range: 6, 12 years), 54.8% were girls, and 54% were White. Most patients (87.9%) were listed with laboratory MELD/PELD scores <15. Waitlist mortality for patients with HPS exception points was rare and not different from patients without HPS. When stratified by pre-LT PaO 2 , hypoxemia severity was not associated with differences in 1-, 3-, or 5-year survival rates after LT ( p = 0.13). However, patients with HPS showed a slightly lower survival rate at 5 years compared with patients without HPS (88.7% vs. 93.4%; p = 0.04). MELD/PELD exceptions for children with HPS mitigated waitlist mortality, and recipients with HPS experienced excellent 5-year survival after LT, although slightly lower than in patients without HPS. Unlike adults with HPS, the severity of pre-LT hypoxemia in children does not impact post-LT survival. These data suggest that adult criteria for granting MELD/PELD exception points may not appropriately capture HPS severity in pediatric patients. Further prospective multicenter studies to examine the risk factors predicting negative survival outcomes in children with HPS are warranted.

Liver Transplant for Non-Hepatocellular Malignancies: A Review for Radiologists

Although traditionally only performed for hepatocellular carcinoma (HCC), the last decade has seen a resurgence in the use of liver transplant (LT) for non-HCC malignancies, likely due to improvements in neoadjuvant treatment regimens as well as the establishment of well-defined eligibility criteria. Given promising survival results, patients with perihilar cholangiocarcinoma, neuroendocrine liver metastases, and hepatic hemangioendothelioma are eligible to receive Model for End Stage Liver Disease (MELD) exception for tumors that meet well-defined criteria. Additional tumors such as colorectal cancer liver metastases, intrahepatic cholangiocarcinoma, and hepatocholangiocarcinoma may undergo transplant at specialized centers with well-defined protocols, although are not yet eligible for MELD exception. Transplant eligibility criteria commonly incorporate imaging findings, yet due to the relatively novel and evolving nature of LT for non-HCC malignancies, radiologists may be unaware of relevant criteria or of the implications of their imaging interpretations. Knowledge of the allocation process, background, and liver transplant selection criteria facilitates the radiologist' active participation in multidisciplinary discussion, leading to better and more equitable care for transplant candidates with non-HCC malignancy. This review provides an overview of transplant allocation and selection criteria in patients with non-HCC malignancy, with an emphasis on imaging features and the role of the radiologist.

Predictors of outcomes following liver transplant in hepatopulmonary syndrome: An OPTN database analysis

Hepatopulmonary syndrome (HPS) is a type of pulmonary vascular disease occurring exclusively in those with underlying liver disease, associated with significant mortality in patients awaiting liver transplantation (LT). LT is curative in HPS, and these patients are granted Model for End Stage Liver Disease (MELD) exception points to expedite LT. The purpose of this study is to use multivariable competing risk Accelerated Failure Time models and propensity matching to examine the relationship between pre-LT hypoxemia and post-LT outcomes in HPS. We performed a retrospective cohort study of UNOS/OPTN database of all adult patients undergoing LT between January 1, 2006 and January 12, 2020. Pre-LT PaO₂ was significantly associated with post-LT mortality in HPS, with each 1 mmHg increase in PaO₂ significantly decreasing the risk of post-LT mortality (coefficient 0.039, HR = 0.95, p = 0.001). HPS patients with a pre-LT PaO₂ < 54 mmHg demonstrated increased mortality following LT as compared to matched non-HPS cirrhotic patients. We conclude that HPS patients with a PaO₂, 54 mmHg are at increased risk of post-LT mortality and may identify high-risk patients who would benefit from additional resources during LT, and that the effects of HPS MELD exception points to optimize post-LT outcomes should be continuously re-evaluated.

Renal Function Parameters and Serum Sodium Enhance Prediction of Wait-List Outcomes in Pediatric Liver Transplantation

BACKGROUND AND AIMS

Reliance on exception points to prioritize children for liver transplantation (LT) stems from concerns that the Pediatric End-Stage Liver Disease (PELD) score underestimates mortality. Renal dysfunction and serum sodium disturbances are negative prognosticators in adult LT candidates and various pediatric populations, but are not accounted for in PELD. We retrospectively evaluated the effect of these parameters in predicting 90-day wait-list death/deterioration among pediatric patients (<12 years) listed for isolated LT in the United States between February 2002 and June 2018.

APPROACH AND RESULTS

Among 4,765 patients, 2,303 (49.3%) were transplanted, and 231 (4.8%) died or deteriorated beyond transplantability within 90 days of listing. Estimated glomerular filtration rate (eGFR) (hazard ratio [HR] 1.09 per 5-unit decrease, 95% confidence interval [CI] 1.06-1.10) and dialysis (HR 7.24, 95% CI 3.57-14.66) were univariate predictors of 90-day death/deterioration (P < 0.001). The long-term benefit of LT persisted in patients with renal dysfunction, with LT as a time-dependent covariate conferring a 2.4-fold and 17-fold improvement in late survival among those with mild and moderate-to-severe dysfunction, respectively. Adjusting for PELD, sodium was a significant nonlinear predictor of outcome, with 90-day death/deterioration risk increased at both extremes of sodium (HR 1.20 per 1-unit decrease below 137 mmol/L, 95% CI 1.16-1.23; HR per 1-unit increase above 137 mmol/L 1.13, 95% CI 1.10-1.17, P < 0.001). A multivariable model incorporating PELD, eGFR, dialysis, and sodium demonstrated improved performance and superior calibration in predicting wait-list outcomes relative to the PELD score.

CONCLUSIONS

Listing eGFR, dialysis, and serum sodium are potent, independent predictors of 90-day death/deterioration in pediatric LT candidates, capturing risk not accounted for by PELD. Incorporation of these variables into organ allocation systems may highlight patient subsets with previously underappreciated risk, augment ability of PELD to prioritize patients for transplantation, and ultimately mitigate reliance on nonstandard exceptions.

Impact of liver-directed therapy and non-therapy on the waiting time list of patient candidates for liver transplantation: retrospective survival analysis

Aim of the study

To determine whether liver-directed therapies (LDT) and no therapy affect waiting list times for liver transplant candidates from a single center.

Material and methods

This retrospective study included patients > 12 years of age diagnosed with hepatocellular carcinoma between January 2014 and June 2019 and followed until the date of transplant, date of delisting, loss to follow-up, or date of death. Waiting list time and associated factors were analyzed using Kaplan-Meier and Cox proportional-hazards methods.

Results

A total of 181 patients met the selection criteria. The mean age was 60 years with standard deviation (SD) of 7.8 years. Sixty-six percent underwent transplant, and 64% were classified within the Milan criteria. Men had a lower median waiting list time than women (191 days vs. 236 days, p = 0.0093). The overall median survival time or time to transplant for 50% of the population was 218 days (95% CI: 195-235). Men displayed a 3.1-fold (95% CI: 1.5-6.2) higher probability of transplantation than women (p = 0.002). Patients who received no therapy had a 5-fold higher probability of undergoing transplantation than patients under arterial LDT (HR [95% CI]: 5 [1.2, 20], p = 0.02). Patients under combined LDT displayed a 70% reduced probability of transplantation compared to patients who received arterial LDTs (p = 0.0009).

Conclusions

LDT was associated with a prolonged stay on the transplant list, likely due to the presence of an aggressive liver tumor. However, LDTs allow the patient to remain active on the liver transplant list, increasing their chances of undergoing transplantation.

LI-RADS and transplantation: challenges and controversies

Patients with early stage hepatocellular carcinoma (HCC) can be cured by liver transplantation. HCC imaging features on CT or MRI are specific enough to allow for definitive diagnosis and treatment without the need of confirmatory biopsy. When applied to the appropriate at-risk population the Liver Imaging Reporting and Data System (LI-RADS) imaging criteria achieve high specificity and positive predictive value for the diagnosis of HCC. The Organ Procurement and Transplantation Network (OPTN) is the United States organization that aims to assure the adequate and fair distribution of livers across candidates. Given the importance of fair organ allocation, OPTN also provides stringent imaging criteria for the diagnosis of HCC aiming to avoid false positive diagnosis. Although most imaging criteria are identical for both systems, discrepancies between LI-RADS and the current OPTN classification system for HCC diagnosis exists. Main differences include, but are not limited to, the binary approach of OPTN to classify lesions as HCC or not, versus the probabilistic algorithmic approach of LI-RADS, technical and interpretation considerations, and the approach towards treated lesions. The purpose of this article is to highlight the similarities and discrepancies between LI-RADS and the current OPTN criteria for HCC diagnosis and the implications that these differences may have on the management of patients who are transplant candidates.

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.

T2 Hepatocellular Carcinoma Exception Policies That Prolong Waiting Time Improve the Use of Evidence-based Treatment Practices

Supplemental Digital Content is available in the text.

Background.

A United Network for Organ Sharing policy change in 2015 created a 6-mo delay in the receipt of T2 hepatocellular carcinoma exception points. It was hypothesized that the policy changed locoregional therapy (LRT) practices and explant findings because of longer expected waiting time.

Methods.

Patients transplanted with a first T2 hepatocellular carcinoma exception application between January 1, 2010 and December 31, 2014 (prepolicy; N = 6562), and those between August 10, 2015 and December 2, 2019 (postpolicy; N = 2345), were descriptively compared using data from United Network for Organ Sharing.

Results.

Median time from first application to transplantation was more homogenous across the US postpolicy, due to greater absolute increases in Regions 3, 6, 10, and 11 (>120 d). During waitlisting, postpolicy candidates received more LRT overall (P < 0.001), with more notable increases in previously short-wait regions. Postpolicy explants were overall more likely to have ≥1 tumor with complete necrosis (23.9 versus 18.4%; P < 0.001) and less likely have ≥1 tumor with no necrosis (32.6% versus 38.5%; P < 0.001). Significant geographic variability in explant treatment response was observed prepolicy with recipients in previously short-wait regions having more frequent tumor viability at transplant. Postpolicy, there were no differences in the prevalence of recipients with ≥1 tumor with 100% or 0% necrosis across regions (P = 0.9 and 0.2, respectively).

Conclusions.

The 2015 T2 exception policy has led to reduced geographic variability in the use of pretransplant LRT and in less frequent tumor viability on explant for recipients in previously short-waiting times.

Matching Graft Quality to Recipient's Disease Severity Based on the Survival Benefit in Liver Transplantation

Persistent shortage and heterogeneous quality of liver grafts encourages the optimization of donor-recipient matching in liver transplantation (LT). We explored whether or not there was a survival benefit (SB) of LT according to the quality of grafts assessed by the Donor Quality Index (DQI) and recipients' disease severity, using the Model for End-Stage Liver Disease (MELD) in 8387 French patients wait-listed between 2009 and 2014. SB associated with LT was estimated using the sequential stratification method in different categories of MELD and DQI. For each transplantation, a stratum was created that matched one transplanted patient with all eligible control candidates. Strata were thereafter combined, and a stratified Cox model, adjusted for covariates, was fitted in order to estimate hazard ratios that qualified the SB according to each MELD and DQI sub-group. A significant SB was observed for all MELD and DQI sub-groups, with the exception of high MELD patients transplanted with "high-risk" grafts. More specifically, in decompensated-cirrhosis patients, "high-risk" grafts did not appear to be detrimental in medium MELD patients. Interestingly, in hepatocellular-carcinoma (HCC) patients, a significant SB was found for all MELD-DQI combinations. For MELD exceptions no SB was found. In terms of SB, "low-risk" grafts appeared appropriate for most severe patients (MELD > 30). Conversely, low/medium MELD and HCC patients presented an SB while allocated "high-risk" grafts. Thus, SB based matching rules for LT candidates might improve the survival of the LT population as a whole.

Impact of Italian Score for Organ Allocation System on Deceased Donor Liver Transplantation: A Monocentric Competing Risk Time-to-Event Analysis

BACKGROUND

Liver transplantation (LT) is the only definitive and curative treatment for patients with end-stage liver disease and hepatocellular carcinoma. We aimed to evaluate the impact of the Italian score for organ allocation (ISO) in terms of the waiting-list mortality, probability of LT, and patient survival after LT.

PATIENT AND METHODS

All of the adult patients on the waiting list for LT at our institute from January 2014 to December 2017 were included in the study. The probabilities of death while on the waiting list, dropout from the list, and LT were compared by means of cumulative incidence functions, in a competing risk time-to-event analysis setting. Uni- and multivariable logistic regression models were used to estimate and compare the probability of death and to find potential risk factors for waiting-list death.

RESULTS

There were 286 patients on the waiting list for LT during the study period, 122 of whom entered the waiting list prior to the implementation of ISO (Group A) and 164 afterward (Group B). Group A had 62 transplants, and Group B had 116 transplants. Group B showed a lesser probability of death (P = .005) and a greater probability of transplant (P < .001) compared to Group A. In the 2 groups, post-transplant survival was similar.

CONCLUSION

Based on preliminary clinical experience from a single transplant center, the ISO allocation system demonstrated an overall reduced probability of patient death while on the waiting list without impairing post-LT survival, suggesting that the ISO system might represent an improved method of organ allocation, with a more beneficial distribution of livers.

Pre-transplant alpha-fetoprotein is associated with post-transplant hepatocellular carcinoma recurrence mortality

BACKGROUND

Although liver transplantation may potentially cure hepatocellular carcinoma (HCC), the risk of HCC recurrence is 8%-20% at five years post-transplant. Pre-transplant alpha-fetoprotein (AFP) is a predictor of HCC recurrence, but it is unknown if pre-transplant AFP also predicts survival in patients with recurrence.

METHODS

We performed a retrospective cohort study using the United Network for Organ Sharing (UNOS) database between 2002 and 2016. We identified adult transplant recipients with HCC recurrence after liver transplantation for HCC and used Cox regression to compare patient survival among different maximum pre-transplant AFP levels.

RESULTS

The cohort (N = 1164) was primarily male, white, and with hepatitis C liver disease. The median time to HCC recurrence was 11.6 months (interquartile range 6.1-26.3). In Cox regression analysis, increasing pre-transplant AFP was associated with poorer survival when adjusting for age, pre-transplant model for end-stage liver disease (MELD), and time to HCC recurrence. For example, patients with pre-transplant AFP ≥500ng/mL had a 1.6-fold higher risk of death versus those with AFP ≤20ng/mL (P < 0.001).

CONCLUSION

Pre-transplant AFP is independently associated with survival in patients with HCC recurrence. These findings further contextualize the importance of pre-transplant AFP in liver transplantation and may improve prognostication for patients with HCC recurrence.

Expression of IL-17 and its gene promoter methylation status are associated with the progression of chronic hepatitis B virus infection

To explore interleukin-17 (IL-17) and its epigenetic regulation during the progression of chronic hepatitis B virus (HBV) infection.A total of 162 patients with chronic HBV infection, including 75 with chronic hepatitis B (CHB), 54 with hepatitis B-associated liver cirrhosis and 33 with hepatitis B-associated hepatocellular carcinoma (HBV-HCC), were enrolled in this study. Thirty healthy adults of the same ethnicity were enrolled in the control group. Whole venous blood was obtained from the patients and normal controls (n = 30). Clinical and laboratory parameters were assessed, and we performed enzyme-linked immunosorbent assay and quantitative real-time PCR to measure the serum levels and relative mRNA expression of IL-17, respectively. IL-17 promoter methylation in peripheral blood mononuclear cells was assessed by methylation-specific PCR. We analyzed the serum and mRNA levels of IL-17 and IL-17 promoter methylation in the 4 groups as well as the effect of methylation on serum IL-17 levels. Correlations between the IL-17 promoter methylation status and clinical parameters were analyzed by Spearman correlation analysis.Compared to the normal control group, the patient groups exhibited significantly higher serum and relative mRNA levels of IL-17. The methylation distribution among the patients was significantly lower than that among the normal controls (P < .05), with the HBV-HCC group showing the lowest IL-17 gene methylation frequency. The average IL-17 promoter CG methylation level was negatively correlated with IL-17 mRNA expression (r = -0.39, P = .03), and negative correlations between IL-17 promoter methylation and prothrombin time activity (r = -0.585, P = .035), alanine aminotransferase (r = -0.522, P < .01), aspartate aminotransferase (r = -0.315, P < .05), and the model for end-stage liver disease score (r = -0.461, P < .05) were observed. IL-17 serum levels in the methylated-promoter groups were significantly lower than those in the unmethylated-promoter groups.IL-17 expression and promoter methylation were associated with chronic HBV infection progression, especially in the HBV-HCC group. The IL-17 promoter status may help clinicians initiate the correct treatment strategy at the CHB stage.

An Advanced Practice Practitioner-Based Program to Reduce 30- and 90-Day Readmissions After Liver Transplantation

Hospital readmissions after liver transplantation (LT) are common and associated with increased morbidity and cost. High readmission rates at our center motivated a change in practice with adoption of a nurse practitioner (NP)-based posttransplant care program. We sought to determine if this program was effective in reducing 30- and 90-day readmissions after LT and to identify variables associated with readmission. We performed a retrospective cohort study of all patients undergoing LT from July 1, 2014, to June 30, 2017, at a tertiary LT referral center. A NP-based posttransplant care program with weekend in-house nurse coordination providers and increased outpatient NP clinic availability was instituted on January 1, 2016. Postdischarge readmission rates at 30 and 90 days were compared in the pre-exposure and postexposure groups, adjusting for associated risk factors. A total of 362 patients were included in the analytic cohort. There were no significant differences in demographics, comorbidities, or index hospitalization characteristics between groups. In the adjusted analyses, the risk of readmission in the postexposure group was significantly reduced relative to baseline at 30 days (hazard ratio [HR] 0.60, 95% confidence interval [CI], 0.39-0.90; P = 0.02) and 90 days (HR, 0.49; 95% CI, 0.34-0.71; P < 0.001). Risk factors positively associated with 30-day readmission included peritransplant dialysis (HR, 1.70; 95% CI, 1.13-2.58; P = 0.01) and retransplant on index hospitalization (HR, 10.21; 95% CI, 3.39-30.75; P < 0.001). Male sex was protective against readmission (HR, 0.66; 95% CI, 0.45-0.97; P = 0.03). In conclusion, implementation of expanded NP-based care after LT was associated with significantly reduced 30- and 90-day readmission rates. LT centers and other service lines using significant postsurgical resources may be able to reduce readmissions through similar programs.

[Anesthesiological aspects of liver transplantation]

Liver transplantation (LTPL) is the only curative option for patients with end stage liver disease (ESLD) or with hepatocellular carcinoma (HCC). Eurotransplant in Leiden, the Netherlands, is responsible for organ allocation. The model of end stage liver disease (MELD) score, which describes the severity of the liver disease, is decisive for organ allocation. The heterogeneous patient collective and hepatic-related comorbidities and their dynamics represent challenges. The anesthesiologist is responsible for evaluating the overall prognosis, whereby cardiac, pulmonary, renal and neurological comorbidities must be taken into consideration. During LTPL surgery is divided into several stages. Besides volume management, heat preservation and coagulation management, major challenges for the anesthesiologist are hemodynamic stabilization and regulation of the acid-base balance.

Development and validation of an optimized prediction of mortality for candidates awaiting liver transplantation

Since 2002, the Model for End-Stage Liver Disease (MELD) has been used to rank liver transplant candidates. However, despite numerous revisions, MELD allocation still does not allow for equitable access to all waitlisted candidates. An optimized prediction of mortality (OPOM) was developed (http://www.opom.online) utilizing machine-learning optimal classification tree models trained to predict a candidate's 3-month waitlist mortality or removal utilizing the Standard Transplant Analysis and Research (STAR) dataset. The Liver Simulated Allocation Model (LSAM) was then used to compare OPOM to MELD-based allocation. Out-of-sample area under the curve (AUC) was also calculated for candidate groups of increasing disease severity. OPOM allocation, when compared to MELD, reduced mortality on average by 417.96 (406.8-428.4) deaths every year in LSAM analysis. Improved survival was noted across all candidate demographics, diagnoses, and geographic regions. OPOM delivered a substantially higher AUC across all disease severity groups. OPOM more accurately and objectively prioritizes candidates for liver transplantation based on disease severity, allowing for more equitable allocation of livers with a resultant significant number of additional lives saved every year. These data demonstrate the potential of machine learning technology to help guide clinical practice, and potentially guide national policy.

Definitive locoregional therapy (LRT) versus bridging LRT and liver transplantation with wait-and-not-treat approach for very early stage hepatocellular carcinoma

PURPOSE

Since the change in the United Network for Organ Sharing (UNOS) policy excluding patients with very early stage hepatocellular carcinoma (veHCC, single tumor nodule <2 cm) from receiving Model for End-stage Liver Disease (MELD) exception points, patients eligible to receive liver transplantation (LT) who fall in this category are commonly treated with locoregional therapy (LRT) after progression to UNOS T2 stage (1 nodule of 2-5 cm or up to 3 nodules, none above 3 cm). The aim of the current study is to compare the outcomes of patients treated with bridging LRT and LT with wait-and-not-treat approach with patients treated with definitive LRT.

METHODS

A retrospective study has been performed on patients with veHCC evaluated in multidisciplinary liver tumor clinic of a large academic center between 2004-2011. Patients eligible for LT were assigned to the wait-and-not-treat group while patients who were not eligible were assigned to the definitive LRT group. Tumor size, time to treatment, severity of liver disease, recurrence and survival from time of detection were reviewed and recorded.

RESULTS

A total of 19 patients were identified and treated with definitive LRT while 57 patients were treated with bridging LRT prior to LT after disease progression to T2 stage. Patients in the definitive LRT group were older (70.4±10.2 years vs. 58.7±5.9 years, P < 0.001) and had more comorbid conditions compared with the wait-and-not-treat group. Mean survival for definitive LRT group at the end of 5 years was 34.3±6.0 months with a median of 30.3 months (95% CI, 5.7-55.0 months) compared with 48.7±2.6 months for the wait-and-not-treat group, respectively (median not reached). The 3- and 5-year survival rates were 53.3% and 33.3% for the definitive LRT group compared with 78.9% and 68.4% for the patients in the wait-and-not-treat group. Survival rate at the end of 5 years was significantly better for the wait-and-not-treat group (P = 0.013).

CONCLUSION

Based on the findings of current retrospective study, treating veHCC (UNOS T1 stage) patients listed for LT with bridging LRT after disease progression to T2 stage appears to be safe and effective with high 5-year survival rates.

Management of bacterial infection in the liver transplant candidate

Bacterial infection (BI) is a common cause of impairment of liver function in patients with cirrhosis, especially in the liver transplant candidates. These patients share an immunocompromised state and increased susceptibility to develop community and hospital-acquired infections. The changing epidemiology of BI, with an increase of multidrug resistant strains, especially in healthcare-associated settings, represents a critical issue both in the waiting list and in the post-operative management. This review focused on the role played by BI in patients awaiting liver transplantation, evaluating the risk of drop-out from the waiting list, the possibility to undergo liver transplantation after recovery from infection or during a controlled infection.

Disparities in Eurotransplant liver transplantation wait-list outcome between patients with and without model for end-stage liver disease exceptions

The sickest-first principle in donor-liver allocation can be implemented by allocating organs to patients with cirrhosis with the highest Model for End-Stage Liver Disease (MELD) scores. For patients with other risk factors, standard exceptions (SEs) and nonstandard exceptions (NSEs) have been developed. We investigated whether this system of matched MELD scores achieves similar outcomes on the liver transplant waiting list for various diagnostic groups in Eurotransplant (ET) countries with MELD-based individual allocation (Belgium, the Netherlands, and Germany). A retrospective analysis of the ET wait-list outflow from December 2006 until December 2015 was conducted to investigate the relation of the unified MELD-based allocation to the risk of a negative wait-list outcome (death on the waiting list or delisting as too sick) as opposed to a positive wait-list outcome (transplantation or delisting as recovered). A total of 16,926 patients left the waiting list with a positive (11,580) or negative (5346) outcome; 3548 patients had a SE, and 330 had a NSE. A negative outcome was more common among patients without a SE or NSE (34.3%) than among patients with a SE (22.6%) or NSE (18.6%; P < 0.001). Analysis by model-based recursive partitioning detected 5 risk groups with different relations of matched MELD to a negative outcome. In Germany, we found the following: (1) no SE or NSE, SE for biliary sepsis (BS); (2) SE for hepatocellular carcinoma (HCC), hepatopulmonary syndrome (HPS), or portopulmonary hypertension (PPH); and (3) SE for primary sclerosing cholangitis (PSC) or polycystic liver disease (PcLD). In Belgium and the Netherlands, we found the following: (4) SE or NSE, or SE for HPS or PPH; and (5) SE for BS, HCC, PcLD, or PSC. In conclusion, SEs and NSEs do not even out risks across different diagnostic groups. Patients with SEs or NSEs appear advantaged toward patients with cirrhosis without SEs or NSEs. Liver Transplantation 23 1256-1265 2017 AASLD.

Waitlisted Candidates With Polycystic Liver Disease Are More Likely to be Transplanted Than Those With Chronic Liver Failure

BACKGROUND

Polycystic liver disease (PCLD) is characterized by cystic replacement of the hepatic parenchyma, leading to hepatic dysfunction, portal hypertension, and hepatomegaly. Patients with liver dysfunction and/or symptomatic disease are eligible for liver transplantation. However, little is known about these patients' waitlist outcomes relative to others with chronic liver disease.

METHODS

We used Organ Procurement and Transplantation Network/United Network for Organ Sharing data from February 27, 2002 to December 31, 2015 to compare waitlist outcomes of adult patients with PCLD to those with chronic liver failure (CLF) and hepatocellular carcinoma.

RESULTS

The study cohort included 620 patients with PCLD, 18 240 patients with hepatocellular carcinoma, and 98 567 patients with CLF. Compared with CLF patients, PCLD patients had significantly lower bilirubin and international normalized ratio at waitlisting, and less ascites and encephalopathy. However, they were significantly more likely to have severe chronic kidney disease. Moreover, patients with PCLD were more than 70% more likely to be transplanted compared with patients with CLF (odds ratio, 1.72; 95% confidence interval, 1.46-2.02) and had significantly longer posttransplant survival (P < 0.001). PCLD patients with exceptions were 5.7 times more likely to be transplanted than those without (odds ratio, 5.67; 95% confidence interval, 3.95-8.15) and measures of hepatic/renal dysfunction were inversely associated with the receipt of exceptions.

CONCLUSIONS

Despite having more preserved liver synthetic function than patients with CLF on the waitlist, patients with PCLD are preferentially transplanted because they frequently receive exception points in an unstandardized fashion.

A Concentric Neighborhood Solution to Disparity in Liver Access That Contains Current UNOS Districts

BACKGROUND

Policymakers are deliberating reforms to reduce geographic disparity in liver allocation. Public comments and the United Network for Organ Sharing Liver and Intestinal Committee have expressed interest in refining the neighborhoods approach. Share 35 and Share 15 policies affect geographic disparity.

METHODS

We construct concentric neighborhoods superimposing the current 11 regions. Using concepts from concentric circles, we construct neighborhoods for each donor service area (DSA) that consider all DSAs within 400, 500, or 600 miles as neighbors. We consider limiting each neighborhood to 10 DSAs and use no metrics for liver supplies and demands. We change Model for End-Stage Liver Disease (MELD) thresholds for the Share 15 policy to 18 or 20 and apply 3- and 5-point MELD proximity boosts to enhance local priority, control travel distances, and reduce disparity. We conduct simulations comparing current allocation with the neighborhoods and sharing policies.

RESULTS

Concentric neighborhoods structures provide an array of solutions where simulation results indicate that they reduce geographic disparity, annual mortalities, and the airplane travel distances by varying degrees. Tuning of the parameters and policy combinations can lead to beneficial improvements with acceptable transplant volume loss and reductions in geographic disparity and travel distance. Particularly, the 10-DSA, 500-mile neighborhood solution with Share 35, Share 15, and 0-point MELD boost achieves such while limiting transplant volume losses to below 10%.

CONCLUSIONS

The current 11 districts can be adapted systematically by adding neighboring DSAs to improve geographic disparity, mortality, and airplane travel distance. Modifications to Share 35 and Share 15 policies result in further improvements. The solutions may be refined further for implementation.

Lower rates of receiving model for end-stage liver disease exception and longer time to transplant among nonalcoholic steatohepatitis hepatocellular carcinoma

Receiving Model for End-Stage Liver Disease (MELD) exception status for hepatocellular carcinoma (HCC) improves wait-list survival and probability of liver transplantation (LT). We aim to evaluate etiology-specific disparities in MELD exception, LT wait-list times, and post-LT outcomes among patients with HCC listed for LT. Using United Network for Organ Sharing 2004-2013 data, we evaluated adults (age > 18 years) with HCC secondary to hepatitis C virus (HCV), nonalcoholic steatohepatitis (NASH), alcoholic cirrhosis (EtOH), hepatitis B virus (HBV), combined EtOH/HCV, and combined HBV/HCV. Multivariate regression models evaluated etiology-specific odds of active exception, probability of receiving LT, and post-LT survival. In total, 10,887 HCC patients were listed for LT from 2004 to 2013. Compared with HCV-HCC patients (86.8%), patients with NASH-HCC (67.7%), and EtOH-HCC (64.4%) had a lower proportion with active MELD exception (P < 0.001). On multivariate regression, NASH-HCC and EtOH-HCC patients had significantly lower odds of active MELD exception compared with HCV-HCC (NASH-HCC-odds ratio [OR], 0.73; 95% confidence interval [CI], 0.58-0.93; P = 0.01; EtOH-HCC-OR, 0.72; 95% CI, 0.59-0.89; P = 0.002). Compared with HCV-HCC patients, NASH-HCC (HR, 0.83; 95% CI 0.76-0.90; P < 0.001), EtOH-HCC (HR, 0.88; 95% CI 0.81-0.96; P = 0.002), and EtOH/HCV-HCC (HR, 0.92; 95% CI 0.85-0.99; P = 0.03) were less likely to receive LT if they had active exception. Without active exception, these discrepancies were more significant (NASH-HCC-HR, 0.22; 95% CI, 0.18-0.27; P < 0.001; EtOH-HCC-HR, 0.22; 95% CI, 0.18-0.26; P < 0.001; EtOH/HCV-HCC-HR, 0.26; 95% CI, 0.22-0.32; P < 0.001). In conclusion, among US adults with HCC listed for LT, patients with NASH-HCC, EtOH-HCC, and EtOH/HCV-HCC were significantly less likely to have active MELD exception compared with HCV-HCC, and those without active exception had a lower likelihood of receiving LT. More research is needed to explore why NASH-HCC patients were less likely to have active MELD exception. Liver Transplantation 22 1356-1366 2016 AASLD.

Liver Transplantation for Cholestatic Liver Diseases in Adults

Liver transplantation (LT) is an established lifesaving therapy for patients with cholestatic liver diseases, including primary cholestatic diseases, namely primary sclerosing cholangitis and primary biliary cirrhosis, as well as secondary forms of cholestatic liver disease, including those with cholestatic complications of LT needing a retransplant. Patients with cholestatic liver diseases can be transplanted for complications of end-stage liver disease or for disease-specific symptoms before the onset of end-stage liver disease. These patients should be regularly assessed. Patient survival after LT for cholestatic liver diseases is generally better than for other indications.

The impact of viral hepatitis-related hepatocellular carcinoma to post-transplant outcomes

Hepatocellular carcinoma (HCC) is the most common complication of HCV infection leading to liver transplantation. We evaluated the impact of aetiology of liver disease on patient and graft survival following liver transplantation for HCC. From the Scientific Registry of Transplant Recipients (2002-2011), all adults who underwent liver transplantation for HCC were retrospectively included. Aetiology of liver disease was grouped into HCV, HBV, HCV-HBV co-infection and nonviral liver disease. Of 8,733 liver transplant recipients with HCC, 5507 had HCV, 631 had HBV, 163 were co-infected, and 2432 had nonviral causes of liver disease. In follow-up (48 ± 32 months), 8.2% had graft failure and 29.5% died. The mean rates of graft failure were 9.5%, 4.7%, 6.1% and 6.4% in HCV, HBV, HCV-HBV co-infection and nonviral liver disease, respectively (P < 0.0001). Post-transplant mortality rate in patients with HBV was 20.2%, HCV 31.0%, HCV-HBV 28.5% and nonviral 28.5% (P < 0.0001). This difference was significant starting one year post-transplant and became even more prominent later in follow-up. Five-year post-transplant survival was 64.7% in HCV, 77.7% in HBV, 71.0% in HCV-HBV and 69.1% in nonviral HCC (P < 0.0001). A diagnosis of HCV in patients with HCC was also independently associated with an increased risk of both graft failure (adjusted hazard ratio = 1.84 (1.46-2.33), P < 0.0001) and mortality (1.35 (1.21-1.50), P < 0.0001) in multivariate analysis. Patients with HCV-related HCC are at higher risk of adverse post-transplant outcomes. These patients should be considered for preemptive interferon-free antiviral therapy prior to or immediately following liver transplantation.

Minimal hepatic encephalopathy and critical flicker frequency are associated with survival of patients with cirrhosis

BACKGROUND & AIMS

Minimal hepatic encephalopathy (MHE) is associated with falls, traffic accidents, and overt HE. However, the association with survival is controversial. We assessed the effects of MHE on the long-term survival of patients with cirrhosis.

METHODS

We performed a prospective study of 117 consecutive patients with cirrhosis seen at a tertiary hospital in Seville, Spain (estimation cohort), followed by a validation study of 114 consecutive patients with cirrhosis seen at 4 hospitals in Spain from January 2004 through December 2007. Patients were examined every 6 months at outpatient clinics through December 2013 (follow-up periods of 5 ± 2.8 y and 4.4 ± 3.9 y for each group, respectively). Cirrhosis was identified by liver biopsy, ultrasound, endoscopic analysis, and biochemical parameters. Liver dysfunction was determined based on model for end-stage liver disease (MELD) and Child-Pugh scores. All patients were administered the critical flicker frequency (CFF) test and psychometric hepatic encephalopathy scores were used to detect MHE. Survival curves were compared using the log-rank test and multivariable analysis was performed using Cox proportional hazards models.

RESULTS

The distributions of Child-Pugh scores were as follows: 66% class A, 31% class B, and 3% class C in the estimation cohort, and 50% class A, 32% class B, and 18% class C in the validation cohort. In the estimation cohort, 24 of 35 patients (68.6%) with a CFF score less than 39 Hz survived for 5 years, whereas 50 of 61 patients (82%) with a CFF score of 39 Hz or higher survived during the follow-up period (log-rank score, 5.07; P = .024). Psychometric hepatic encephalopathy scores did not correlate with survival. In multivariable analysis, older age (hazard ratio [HR], 1.07; 95% confidence interval [CI], 1.02-1.12; P = .009), CFF score less than 39 Hz (HR, 4.36; 95% CI, 1.67-11.37; P = .003), and MELD score (HR, 1.40; 95% CI, 1.21-1.63; P = .0001) were associated independently with survival during the follow-up period. In the validation cohort, CFF score less than 39 Hz and MELD score also were associated with patient survival during the follow-up period. MHE had no effect on the survival of patients with MELD scores less than 10 (among patients with CFF scores ≥39 Hz, 94.5% survived for 5 years vs 91.9% of patients with CFF scores <39 Hz; log-rank score, 0.64; P = .423). Fewer patients with MELD scores of 10-15 and MHE survived for 5 years (44.4%; 12 of 27) than those with MELD scores greater than 15 without MHE (61.5%; 8 of 13) (P < .05). Only 2 of 12 patients (16.7%) with MELD scores of 15 or higher and MHE survived for 5 years (log-rank score, 90.56; P = .0001).

CONCLUSIONS

MHE is associated with a reduced 5-year survival rate of patients with cirrhosis. Evaluation of MHE could help predict survival times and outcomes of patients with specific MELD scores. The CFF could help physicians determine prognoses of patients with cirrhosis.

Outcomes of liver transplantation for end-stage biliary disease: A comparative study with end-stage liver disease

AIM: To evaluate the outcomes of patients with end-stage biliary disease (ESBD) who underwent liver transplantation, to define the concept of ESBD, the criteria for patient selection and the optimal operation for decision-making.

METHODS: Between June 2002 and June 2014, 43 patients with ESBD from two Chinese organ transplantation centres were evaluated for liver transplantation. The causes of liver disease were primary biliary cirrhosis (n = 8), cholelithiasis (n = 8), congenital biliary atresia (n = 2), graft-related cholangiopathy (n = 18), Caroli’s disease (n = 2), iatrogenic bile duct injury (n = 2), primary sclerosing cholangitis (n = 1), intrahepatic bile duct paucity (n = 1) and Alagille’s syndrome (n = 1). The patients with ESBD were compared with an end-stage liver disease (ESLD) case control group during the same period, and the potential prognostic values of multiple demographic and clinical variables were assessed. The examined variables included recipient age, sex, pre-transplant clinical status, pre-transplant laboratory values, operation condition and postoperative complications, as well as patient and allograft survival rates. Survival analysis was performed using Kaplan-Meier curves, and the rates were compared using log-rank tests. All variables identified by univariate analysis with P values < 0.100 were subjected to multivariate analysis. A Cox proportional hazard regression model was used to determine the effect of the study variables on outcomes in the study group.

RESULTS: Patients in the ESBD group had lower model for end-stage liver disease (MELD)/paediatric end-stage liver disease (PELD) scores and a higher frequency of previous abdominal surgery compared to patients in the ESLD group (19.2 ± 6.6 vs 22.0 ± 6.5, P = 0.023 and 1.8 ± 1.3 vs 0.1 ± 0.2, P = 0.000). Moreover, the operation time and the time spent in intensive care were significantly higher in the ESBD group than in the ESLD group (527.4 ± 98.8 vs 443.0 ± 101.0, P = 0.000, and 12.74 ± 6.6 vs 10.0 ± 7.5, P = 0.000). The patient survival rate in the ESBD group was not significantly different from that of the ESBD group at 1, 3 and 5 years (ESBD: 90.7%, 88.4%, 79.4% vs ESLD: 84.9%, 80.92%, 79.0%, χ² = 0.194, P = 0.660). The graft-survival rates were also similar between the two groups at 1, 3 and 5 years (ESBD: 90.7%, 85.2%, 72.7% vs ESLD: 84.9%, 81.0%, 77.5%, χ² = 0.003, P = 0.958). Univariate analysis identified MELD/PELD score (HR = 1.213, 95%CI: 1.081-1.362, P = 0.001) and bleeding volume (HR = 0.103, 95%CI: 0.020-0.538, P = 0.007) as significant factors affecting the outcomes of patients in the ESBD group. However, multivariate analysis revealed that MELD/PELD score (HR = 1.132, 95%CI: 1.005-1.275, P = 0.041) was the only negative factor that was associated with short survival time.

CONCLUSION: MELD/PELD criteria do not adequately measure the clinical characteristics and staging of ESBD. The allocation system based on MELD/PELD criteria should be re-evaluated for patients with ESBD.