The Evolution of Organ Allocation for Liver Transplantation: Tackling Geographic Disparity Through Broader Sharing

The Effect of Model for End-Stage Liver Disease 3.0 on Disparities between Patients with and without Hepatocellular Carcinoma in Korea

PURPOSE

The model for end-stage liver disease (MELD) 3.0 has recently been suggested for determining liver allocation. We aimed to apply MELD 3.0 to a Korean population and to discover differences between patients with and without hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

This study is a retrospective study of 2203 patients diagnosed with liver cirrhosis at Severance Hospital between 2016-2022. Harrell's concordance index was used to validate the ability of MELD scores to predict 90-day survival.

RESULTS

During a mean follow-up of 12.9 months, 90-day survival was 61.9% in all patients, 50.4% in the HCC patients, and 74.8% in the non-HCC patients. Within the HCC patients, the concordance index for patients on the waitlist was 0.653 using MELD, which increased to 0.753 using MELD 3.0. Among waitlisted patients, the 90-day survival of HCC patients was worse than that of non-HCC patients with MELD scores of 31-37 only (69.7% vs. 30.0%, p=0.001). Applying MELD 3.0, the 90-day survival of HCC patients was worse than that of non-HCC patients across a wider range of MELD 3.0 scores, compared to MELD, with MELD 3.0 scores of 21-30 and 31-37 (82.0% vs. 72.5% and 72.3% vs. 24.3%, p=0.02 and p<0.001, respectively).

CONCLUSION

MELD 3.0 predicted 90-day survival of the HCC patients more accurately than original MELD score; however, the disparity between HCC and non-HCC patients increased, particularly in patients with MELD scores of 21-30. Therefore, a novel exception score is needed or the current exception score system should be modified.

Center expansion of liver transplants using donation after circulatory death organs is associated with reduced overall waitlist mortality

INTRODUCTION

Waitlist outcomes in liver transplantation (LT) for individual recipients are improved by use of allografts procured through donation after circulatory death (DCD). However, the impact of increased DCD acceptance on overall center outcomes is unknown.

METHODS

Using the United Network for Organ Sharing database, 88 centers performing an average of ≥10 LTs/year between 1/2004 and 12/2019 were compared by percent DCD use quartile and categorized into four phenotypes according to temporal usage trends. Overall center median Model for End-stage Liver Disease at LT (MMaT), waitlist mortality, and waiting time were evaluated.

RESULTS

The overall DCD rate was 6.1% (N = 4906/80,709), ranging from 0% to 25.5%. Centers in the top DCD use quartile had lower MMaT (24 vs. 26; p < .001) and shorter overall waiting times (median 66 days vs. 90 days; p < .001) compared to bottom quartile centers. MMaT increased less over time at centers with increasing DCD use and was lower than at centers with declining DCD use (27 vs. 32; p = .017). Overall waitlist mortality between 2016 and 2019 was lower at increasing DCD use centers (17.8% vs. 22.5%, p = .034), yet did not affect 1-year mortality (p = .747).

CONCLUSIONS

The improved waitlist outcomes at centers with expanded DCD use extend beyond DCD recipients alone without negative consequences to overall post-LT center metrics.

Recovery From Acute Kidney Injury Requiring Dialysis in Patients With Cirrhosis: A Population-Based Study

RATIONALE & OBJECTIVE

The decision to initiate kidney replacement therapy (KRT) for acute kidney injury (AKI) in cirrhosis remains controversial as it is unclear which patients will benefit. We sought to characterize factors associated with recovery from AKI requiring KRT in patients with cirrhosis to inform shared clinical decision-making.

STUDY DESIGN

Population-based retrospective cohort study.

SETTING & PARTICIPANTS

Adult patients from Ontario, Canada identified, using administrative data, to have cirrhosis at the time of admission to hospital with AKI (based on serum creatinine) requiring KRT (01/01/2009-12/31/2016) and followed until 12/31/2017.

EXPOSURES

Demographics and comorbidities prior to admission.

OUTCOMES

Kidney recovery defined as the absence of KRT for at least 30 days.

ANALYTICAL APPROACH

The cumulative incidences of kidney recovery, death, and liver transplantation were calculated at 1, 3, 6, and 12 months and independent predictors of kidney recovery were evaluated using Fine and Gray competing risk regression models that generated subdistribution hazards ratios (sHR).

RESULTS

Overall, 722 patients were included (median age 61 years [IQR 54-68]; MELD-Na 26 [IQR 22-34]; 66% male; 52% had viral hepatitis, 25% non-alcoholic fatty liver disease, 18% alcohol-associated liver disease). The cumulative incidences of kidney recovery at 1, 3, 6, and 12 months were 3%, 22%, 25%, and 26%, respectively. Higher MELD-Na score (sHR 0.72 per 5 units, 95%CI 0.65-0.80), acute-on-chronic liver failure (sHR 0.61, 95%CI 0.43-0.86), and sepsis (sHR 0.57, 95%CI 0.41-0.81) were associated with a lower hazard of kidney recovery while those on a liver transplant waitlist (sHR 3.10, 95% CI 1.96-4.88) and who were admitted to a teaching hospital (sHR 1.48, 95%CI 1.05-2.08) were more likely to experience kidney recovery.

LIMITATIONS

Observational design, AKI etiology not identified.

CONCLUSIONS

Kidney recovery from KRT occurred in only one-quarter of patients and was very unlikely after 3-months. These findings provide information regarding prognosis that may guide decisions regarding KRT initiation and continuation.

Circuitous Path to Live Donor Liver Transplantation from the Coordinator's Perspective

Background: The live donor liver transplantation (LDLT) process is circuitous and requires a considerable amount of coordination and matching in multiple aspects that the literature does not completely address. From the coordinators’ perspective, we systematically analyzed the time and risk factors associated with interruptions in the LDLT process. Methods: In this retrospective single center study, we reviewed the medical records of wait-listed hospitalized patients and potential live donors who arrived for evaluation. We analyzed several characteristics of transplant candidates, including landmark time points of accompanied live donation evaluation processes, time of eventual LDLT, and root causes of not implementing LDLT. Results: From January 2014 to January 2021, 417 patients (342 adults and 75 pediatric patients) were enrolled, of which 331 (79.4%) patients completed the live donor evaluation process, and 205 (49.2%) received LDLT. The median time from being wait-listed to the appearance of a potential live donor was 19.0 (interquartile range 4.0–58.0) days, and the median time from the appearance of the donor to an LDLT or a deceased donor liver transplantation was 68.0 (28.0–188.0) days. The 1-year mortality rate for patients on the waiting list was 34.3%. Presence of hepatitis B virus, encephalopathy, and hypertension as well as increased total bilirubin were risk factors associated with not implementing LDLT, and biliary atresia was a positive predictor. The primary barriers to LDLT were a patient’s critical illness, donor’s physical conditions, motivation for live donation, and stable condition while on the waiting list. Conclusions: Transplant candidates with potential live liver donors do not necessarily receive LDLT. The process requires time, and the most common reason for LDLT failure was critical diseases. Aggressive medical support and tailored management policies for these transplantable patients might help reduce their loss during the process.

Impact of County Health Rankings on Nationwide Liver Transplant Outcomes

BACKGROUND

There is limited information concerning whether social determinants of health affect postliver transplant (LT) outcomes. This study aims to understand to what extent the health of LT recipients' counties of residence influence long-term LT outcomes.

METHODS

We used the United Network for Organ Sharing data to identify adult LT recipients transplanted between January 2010 and June 2018. Patient-level data were matched to county-level County Health Ranking (CHR) data using transplant recipient zip code, and nationwide CHRs were created. Mixed-effects Cox proportional hazards models were used to examine associations between CHRs and graft and patient survival post-LT.

RESULTS

Health outcomes rank was significantly associated with posttransplant graft and patient survival, with worst tertile counties showing a 13% increased hazard of both graft failure and patient mortality compared to the best tertile counties.

CONCLUSIONS

Although county health is associated with LT outcomes, it also appears that LT recipient selection is effective at mitigating major disparities based on county of residence and helps yield equitable outcomes in this respect.

Geographic disparities in transplantation

PURPOSE OF REVIEW

The Final Rule clearly states that geography should not be a determinant of a chance of a potential candidate being transplanted. There have been multiple concerns about geographic disparities in patients in need of solid organ transplantation. Allocation policy adjustments have been designed to address these concerns, but there is little evidence that the disparities have been solved. The purpose of this review is to describe the main drivers of geographic disparities in solid organ transplantation and how allocation policy changes and other potential actions could impact these inequalities.

RECENT FINDINGS

Geographical disparities have been reported in kidney, pancreas, liver, and lung transplantation. Organ Procurement and Transplant Network has modified organ allocation rules to underplay geography as a key determinant of a candidates' chance of receiving an organ. Thus, heart, lung, and more recently liver and Kidney Allocation Systems have incorporated broader organ sharing to reduce geographical disparities. Whether these policy adjustments will indeed eliminate geographical disparities are still unclear.

SUMMARY

Modern allocation policy focus in patients need, regardless of geography. Innovative actions to further reduce geographical disparities are needed.

The effect of immunosuppression therapy on activities of daily living and comfort level after liver transplantation

OBJECTIVES

This study was carried out to investigate the effect of immunosuppression therapy on activities of daily living and comfort level after liver transplantation.

MATERIALS AND METHODS

This study was conducted in a descriptive and correlational type with the participation of 148 liver transplant patients hospitalized in the liver transplant center of a university hospital. Personal Information Form, Katz Activities of Daily Living Scale and General Comfort Questionnaire were used in data collection. The data analysis was performed with IBM SPSS (Statistical Package for the Social Sciences) Statistics 25.

RESULTS

According to the results obtained from the study, it was determined that 31.1% of the patients were 58 years old and over, 20.9% of them were between 48- and 57 years old, and 81.8% of them were male. It was found that 61.5% of the patients were between the 11th and 21st days after transplantation and 26.4% of them were given oxygen with a non-invasive catheter. It was determined that the patients were semi-independent in activities of daily living and had a moderate comfort level.

CONCLUSIONS

It is not always possible for liver transplant patients to effectively deal with their condition. The low comfort level and quality of life of patients who have undergone liver transplantation should be noticed, and social, economic and psychological support should be provided.

Balancing Efficiency and Fairness in Liver Transplant Access: Tradeoff Curves for the Assessment of Organ Distribution Policies

BACKGROUND

Current distribution policies have resulted in persistent geographic disparity in access to donated livers across the country for waitlisted candidates.

METHODS

Using mathematical optimization, and subsequently the Liver Simulation Allocation Model, the following organ distribution concepts were assessed: (1) current policy, (2) proposed alternative models, and (3) a novel continuous distribution model. A number of different scenarios for each policy distribution concept were generated and analyzed through efficiency-fairness tradeoff curves.

RESULTS

The continuous distribution concept allowed both for the greatest reduction in patient deaths and for the most equitable geographic distribution across comparable organ transportation burden. When applied with an Optimized Prediction of Mortality allocation scheme, continuous distribution allowed for a significant reduction in number of deaths-on the order of 500 lives saved annually (https://livervis.github.io/).

CONCLUSIONS

Tradeoff curves allow for a visualized understanding on the efficiency/fairness balance, and have demonstrated that liver candidates awaiting transplant would benefit from a model employing continuous distribution as this holds the greatest advantage for mortality reduction. Development and implementation of continuous distribution models for all solid organ transplants may allow for minimization of the geographic disparity in organ distribution, and allow for efficient and fair access to a limited national resource for all candidates.

Improved survival after treatments of patients with nonalcoholic fatty liver disease associated hepatocellular carcinoma

Worldwide, nonalcoholic fatty liver disease (NAFLD) has reached epidemic proportions and in parallel, hepatocellular carcinoma (HCC) has become one of the fastest growing cancers. Despite the rise in these disease entities, detailed long-term outcomes of large NAFLD-associated HCC cohorts are lacking. In this report, we compared the overall and recurrence-free survival rates of NAFLD HCC cases to patients with HBV and HCV-associated HCC cases. Distinguishing features of NAFLD-associated HCC patients in the cirrhosis and non-cirrhosis setting were also identified. We conducted a retrospective study of 125 NAFLD, 170 HBV and 159 HCV HCC patients, utilizing clinical, pathological and radiographic data. Multivariate regression models were used to study the overall and recurrence-free survival. The overall survival rates were significantly higher in the NAFLD-HCC cases compared to HBV-HCC (HR = 0.35, 95% CI 0.15-0.80) and HCV-HCC (HR = 0.37, 95% CI 0.17-0.77) cases. The NAFLD-HCC patients had a trend for higher recurrence-free survival rates compared to HBV and HCV-HCC cases. Within the NAFLD group, 18% did not have cirrhosis or advanced fibrosis; Hispanic ethnicity (OR = 12.34, 95% CI 2.59-58.82) and high BMI (OR = 1.19, 95% CI 1.07-1.33) were significantly associated with having cirrhosis. NAFLD-HCC cases were less likely to exhibit elevated serum AFP (p < 0.0001). After treatments, NAFLD-related HCC patients had longer overall but not recurrence-free survival rates compared to patients with viral-associated HCC. Non-Hispanic ethnicity and normal BMI differentiated non-cirrhosis versus cirrhosis NAFLD HCC. Further studies are warranted to identify additional biomarkers to stratify NAFLD patients without cirrhosis who are at risk for HCC.

Impact of Model for End-stage Liver Disease Score-based Allocation System in Korea: A Nationwide Study

BACKGROUND

In June 2016, the Korean Network for Organ Sharing implemented a Model for End-stage Liver Disease (MELD) score-based allocation system to better prioritize deceased-donor liver transplant (DDLT) candidates. The aim of this study was to assess the impact of this allocation system.

METHODS

We compared waiting list and posttransplant outcomes during the first year of operation of the MELD allocation system (from June 2016 to May 2017) with an equivalent period before its implementation (from June 2015 to May 2016).

RESULTS

A total of 3041 candidates were listed for DDLT (1464 pre-MELD, 1577 post-MELD era) and 892 patients received DDLT during the study period. A decrease in waiting list mortality and an increase in DDLT rate were observed after MELD implementation. However, the number of living donor liver transplants did not differ significantly pre- to post-MELD. As was expected, introduction of the MELD allocation system increased mean MELD scores at DDLT (24.1 ± 8.3 pre-MELD, 34.5 ± 7.0 post-MELD era, P < 0.001). Posttransplant patient survival rates at 1-year were 79.9% in pre-MELD era and 76.2% in post-MELD era (P = 0.184). The proportion of interregional organ transfer increased from 25.1% to 40.5%. Furthermore, transplant benefits increased with MELD scores.

CONCLUSIONS

The MELD system was found to address the goal of fairness well. Implementation of the MELD system improved equity in terms of access to DDLT regardless of regions. Although a greater proportion of more severely ill patients received DDLT after MELD implementation, posttransplant survivals remained unchanged.

Basic principles of liver allocation and development over the years

PURPOSE OF REVIEW

Prior to the enactment of the National Organ Transplant Act in 1984, there was no organized system to allocate donor organs in the United States. The process of liver allocation has come a long way since then, including the development and implementation of the Model for End-stage Liver Disease, which is an objective estimate of risk of mortality among candidates awaiting liver transplantation.

RECENT FINDINGS

The Liver Transplant Community is constantly working to optimize the distribution and allocation of scare organs, which is essential to promote equitable access to a life-saving procedure in the setting of clinical advances in the treatment of liver disease. Over the past 17 years, many changes have been made. Most recently, liver distribution changed such that deceased donor livers will be distributed based on units established by geographic circles around a donor hospital rather than the current policy, which uses donor service areas as the unit of distribution. In addition, a National Liver Review Board was created to standardize the process of determining liver transplant priority for candidates with exceptional medical conditions. The aim of these changes is to allocate and distribute organs in an efficient and equitable fashion.

SUMMARY

The current review provides a historical perspective of liver allocation and the changing landscape in the United States.

Migration of Patients for Liver Transplantation and Waitlist Outcomes

BACKGROUND & AIMS

Patients in need of liver transplantation may travel to improve their chance of receiving an organ. We evaluated factors to determine which transplant candidates travel to other regions to increase their chances of receiving a liver and effects of travel on waitlist outcomes.

METHODS

We performed a retrospective cohort study of all adult patients registered for primary deceased donor liver transplantation in the United States from January 2004 to December 2016. Zip code data were used to calculate the travel distance from a patient's residence to centers at which they were on the waitlist or received a liver transplant. Distant listing and migration were defined as placement on a waitlist and receipt of liver transplantation, respectively, outside the home transplantation region and greater than 500 miles from the home zip code. We assessed the effect of distant listing on outcomes (death and liver transplantation) and predictors of distant listing or migration using multivariable analyses.

RESULTS

There were 104,914 waitlist registrations during the study period; of these, 2930 (2.8%) pursued listing at a distant center. Of waitlist registrants, 60,985 received liver transplants, of whom 1985 (3.3%) had migrated. In a multivariable competing risk analysis in which liver transplantation was considered as a competing event, distant listing was associated with a 22% reduction in the risk of death within 1 year (subhazard ratio, 0.78; 95% CI, 0.70-0.88). Distant listing and migration were associated with non-black race, non-Medicaid payer, residence in a higher income area, and education beyond high school.

CONCLUSIONS

Placement on a liver transplant waitlist outside the home transplantation region is associated with reduced waitlist mortality and an increased probability of receiving a liver transplant. Geographic disparities in access to liver transplantation have disproportionate effects on patients who are minorities, have lower levels of education, or have public insurance.

Influence of the procurement surgeon on transplanted abdominal organ outcomes: An SRTR analysis to evaluate regional organ procurement collaboration

Single-center studies have demonstrated regional organ procurement collaboration to reduce travel redundancy and improve procurement efficiency. We studied deceased donor kidney, liver, and pancreas transplants performed in the United States between 2002 and 2014 using the Scientific Registry of Transplant Recipients (SRTR). We compared graft failure (GF), death-censored graft failure (DCGF), and patient death (PD) between organs procured by surgeons from the recipient's center (transplant procurement team [TPT]) versus surgeons from a different center (NTPT). Primary nonfunction (PNF) was assessed for liver and kidney and delayed graft function (DGF) for kidney using mixed-effects logistic modeling. There were 64 906 liver (61.6% TPT), 118 152 kidney (26.1% TPT), 10 832 simultaneous pancreas kidney (SPK; 56.6% TPT), and 4378 solitary pancreas (SP; 34.0% TPT) transplants. When compared to NTPT, DCGF for organs procured by TPT was significantly less for liver (adjusted HR: 0.93; 95% CI: 0.88-0.98) and marginally significant for kidney (0.97; 0.93-1.00) and SPK (0.90; 0.82-1.00), and not significant for SP (0.98; 0.86 -1.11). DGF for TPT kidney was significantly lower (adjusted OR 0.91; 0.87-0.95). Albeit modest, our findings demonstrate a difference between locally procured organs and those procured by the implanting team. Elucidating the etiology of these differences will enhance regional organ procurement collaboration.

Immunosuppression following organ transplantation. Part 1: mechanisms and immunosuppressive agents

Solid organ transplantation has revolutionised medical care by providing a definitive cure for a wide spectrum of end-stage medical conditions. This treatment, however, does not come without complications and poses the risks of rejection, life-threatening infection, malignancies and recurrent organ failure, with significant impacts on patient outcomes. One of the major challenges involved in optimising post-transplant outcomes is managing the immune system's response to the transplanted graft and preventing organ rejection. This is mainly accomplished through the use of immunosuppressant agents, which have become a mainstay of treatment for a majority of post-transplant patients. This article, the first of two parts, discusses the concept of immunosuppression and its importance in the care of patients who have received an organ transplant. It focuses on the pathophysiologic mechanisms involved in transplant rejection and discusses the pharmacologic aspects of immunosuppression and its implications for patient care.

Implementing an innovated preservation technology: The American Society of Transplant Surgeons' (ASTS) Standards Committee White Paper on Ex Situ Liver Machine Perfusion

The pervasive shortage of deceased donor liver allografts contributes to significant waitlist mortality despite efforts to increase organ donation. Ex vivo liver perfusion appears to enhance preservation of donor organs, extending viability and potentially evaluating function in organs previously considered too high risk for transplant. These devices pose novel challenges for organ allocation, safety, training, and finances. This white paper describes the American Society of Transplant Surgeons' belief that organ preservation technology is a vital advance, but its use should not change fundamental aspects of organ allocation. Additional data elements need to be collected, made available for organ assessment by transplant professionals to allow determination of organ suitability in the case of reallocation and incorporated into risk adjustment methodology. Finally, further work is needed to determine the optimal strategy for management and oversight of perfused organs prior to transplantation.

Geographic disparities in donor lung supply and lung transplant waitlist outcomes: A cohort study

Despite the Final Rule mandate for equitable organ allocation in the United States, geographic disparities exist in donor lung allocation, with the majority of donor lungs being allocated locally to lower-priority candidates. We conducted a retrospective cohort study of 19 622 lung transplant candidates waitlisted between 2006 and 2015. We used multivariable adjusted competing risk survival models to examine the relationship between local lung availability and waitlist outcomes. The primary outcome was a composite of death and removal from the waitlist for clinical deterioration. Waitlist candidates in the lowest quartile of local lung availability had an 84% increased risk of death or removal compared with candidates in the highest (subdistribution hazard ratio [SHR]: 1.84, 95% confidence interval [CI]: 1.51-2.24, P < .001). The transplantation rate was 57% lower in the lowest quartile compared with the highest (SHR: 0.43, 95% CI: 0.39-0.47). The adjusted death or removal rate decreased by 11% with a 50% increase in local lung availability (SHR: 0.89, 95% CI: 0.85-0.93, P < .001) and the adjusted transplantation rate increased by 19% (SHR: 1.19, 95% CI: 1.17-1.22, P < .001). There are geographically disparate waitlist outcomes in the current lung allocation system. Candidates listed in areas of low local lung availability have worse waitlist outcomes.

Prognosis of Patients with Cirrhosis and AKI Who Initiate RRT

BACKGROUND AND OBJECTIVES

Literature on the prognosis of patients with cirrhosis who require RRT for AKI is sparse and is confounded by liver transplant eligibility. An update on outcomes in the nonlisted subgroup is needed. Our objective was to compare outcomes in this group between those diagnosed with hepatorenal syndrome and acute tubular necrosis, stratifying by liver transplant listing status.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Retrospective cohort study of patients with cirrhosis acutely initiated on hemodialysis or continuous RRT at five hospitals, including one liver transplant center. Multivariable regression and survival analysis were performed.

RESULTS

Four hundred seventy-two subjects were analyzed (341 not listed and 131 listed for liver transplant). Among nonlisted subjects, 15% (51 of 341) were alive at 6 months after initiating RRT. Median survival was 21 (interquartile range [IQR], 8, 70) days for those diagnosed with hepatorenal syndrome and 12 (IQR, 3, 43) days for those diagnosed with acute tubular necrosis (P=0.25). Among listed subjects, 48% (63 of 131) received a liver transplant. Median transplant-free survival was 15 (IQR, 5, 37) days for those diagnosed with hepatorenal syndrome and 14 (IQR, 4, 31) days for those diagnosed with acute tubular necrosis (P=0.60). When stratified by transplant listing, with adjusted Cox models we did not detect a difference in the risk of death between hepatorenal syndrome and acute tubular necrosis (hazard ratio [HR], 0.81; 95% confidence interval [95% CI], 0.59 to 1.11, among those not listed; HR, 0.73; 95% CI, 0.44 to 1.19, among those listed).

CONCLUSIONS

Cause of AKI was not significantly associated with mortality in patients with cirrhosis who required RRT. Among those not listed for liver transplant, mortality rates were extremely high in patients both with hepatorenal syndrome and acute tubular necrosis.

PODCAST

This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2017_11_09_CJASNPodcast_18_1_A.mp3.

Between-center disparities in access to heart transplantation in France: contribution of candidate and center factors - A comprehensive cohort study

Transplantation represents the last option for patients with advanced heart failure. We assessed between-center disparities in access to heart transplantation in France 1 year after registration and evaluated the contribution of factors to these disparities. Adults (n = 2347) registered on the French national waiting list between January 1, 2010, and December 31, 2014, in the 23 transplant centers were included. Associations between candidate and transplant center characteristics and access to transplantation were assessed by proportional hazards frailty models. Candidate blood groups O and A, sensitization, and body mass index ≥30 kg/m² were independently associated with lower access to transplantation, while female gender, severity of heart failure, and high serum bilirubin levels were independently associated with greater access to transplantation. Center factors significantly associated with access to transplantation were heart donation rate in the donation service area, proportion of high-urgency candidates among listed patients, and donor heart offer decline rate. Between-center variability in access to transplantation increased by 5% after adjustment for candidate factors and decreased by 57% after adjustment for center factors. After adjustment for candidate and center factors, five centers were still outside of normal variability. These findings will be taken into account in the future French heart allocation system.

Geographic Disparities in Liver Availability: Accidents of Geography, or Consequences of Poor Social Policy?

Recently, a redistricting proposal intended to equalize Model for End-stage Liver Disease score at transplant recommended expanding liver sharing to mitigate geographic variation in liver transplantation. Yet, it is unclear whether variation in liver availability is arbitrary and a disparity requiring rectification or reflects differences in access to care. We evaluate the proposal's claim that organ supply is an "accident of geography" by examining the relationship between local organ supply and the uneven landscape of social determinants and policies that contribute to differential death rates across the United States. We show that higher mortality leading to greater availability of organs may in part result from disproportionate risks incurred at the local level. Disparities in public safety laws, health care infrastructure, and public funding may influence the risk of death and subsequent availability of deceased donors. These risk factors are disproportionately prevalent in regions with high organ supply. Policies calling for organ redistribution from high-supply to low-supply regions may exacerbate existing social and health inequalities by redistributing the single benefit (greater organ availability) of greater exposure to environmental and contextual risks (e.g. violent death, healthcare scarcity). Variation in liver availability may not be an "accident of geography" but rather a byproduct of disadvantage.

A data science approach for quantifying spatio-temporal effects to graft failures in organ transplantation

The transplantation of solid organs is one of the most important accomplishments of modern medicine. Yet, organ shortage is a major public health issue; 8,000 people died while waiting for an organ in 2014. Meanwhile, the allocation system currently implemented can lead to organs being discarded and the medical community still investigates factors that affects early graft failure such as distance and ischemic time. In this paper, we investigate early graft failure under a spatio-temporal perspective using a data science unified approach for all six organs that is based on complementary cumulative analysis of both distance and ischemic time. Interestingly, although distance seems to highly affect some organs (e.g. liver), it appears to have no effect on others (e.g. kidney). Similarly, the results on ischemic time confirm it affects early graft failure with higher influence for some organs such as (e.g. heart) and lower influence for others such as (e.g. kidney). This poses the question whether the allocation policies should be individually designed for each organ in order to account for their particularities as shown in this work.

Regional Differences in Communication Process and Outcomes of Requests for Solid Organ Donation

Although federal mandate prohibits the allocation of solid organs for transplantation based on "accidents of geography," geographic variation of transplantable organs is well documented. This study explores regional differences in communication in requests for organ donation. Administrative data from nine partnering organ procurement organizations and interview data from 1339 family decision makers (FDMs) were compared across eight geographically distinct US donor service areas (DSAs). Authorization for organ donation ranged from 60.4% to 98.1% across DSAs. FDMs from the three regions with the lowest authorization rates reported the lowest levels of satisfaction with the time spent discussing donation and with the request process, discussion of the least donation-related topics, the highest levels of pressure to donate, and the least comfort with the donation decision. Organ procurement organization region predicted authorization (odds ratios ranged from 8.14 to 0.24), as did time spent discussing donation (OR = 2.11), the number of donation-related topics discussed (OR = 1.14), and requesters' communication skill (OR = 1.14). Standardized training for organ donation request staff is needed to ensure the highest quality communication during requests, optimize rates of family authorization to donation in all regions, and increase the supply of organs available for transplantation.

Fair is fair: We must re-allocate livers for transplant

The 11 original regions for organ allocation in the United States were determined by proximity between hospitals that provided deceased donors and transplant programs. As liver transplants became more successful and demand rose, livers became a scarce resource. A national system has been implemented to prioritize liver allocation according to disease severity, but the system still operates within the original procurement regions, some of which have significantly more deceased donor livers. Although each region prioritizes its sickest patients to be liver transplant recipients, the sickest in less liver-scarce regions get transplants much sooner and are at far lower risk of death than the sickest in more liver-scarce regions. This has resulted in drastic and inequitable regional variation in preventable liver disease related death rate.A new region districting proposal - an eight district model - has been carefully designed to reduce geographic inequities, but is being fought by many transplant centers that face less scarcity under the current model. The arguments put forth against the new proposal, couched in terms of fairness and safety, will be examined to show that the new system is technologically feasible, will save more lives, and will not worsen socioeconomic disparity. While the new model is likely not perfect, it is a necessary step toward fair allocation.

Succinct guide to liver transplantation for medical students

Literature on liver transplantation for use in medical education is limited and as yet unsatisfactory. The aim of this article is to help medical students gain enough insight into the reality of being a liver transplant recipient. This is crucial so in the future they can feel confident in approaching these patients with adequate knowledge and confidence. The knowledge-tree based learning core topics are designed for a 2-h class including indication/contraindication in the real-world setting, model for end stage liver disease scoring and organ allocation policy, liver transplantation for hepatic malignancy, transplantation surgery, immunosuppression strategy in practical consideration, and management of viral hepatitis. The rationales of each topic are discussed comprehensively for better understanding by medical students. Recipient candidates may have reversible contraindications that halt the surgery temporarily and therefore, it warrants re-evaluation before transplant. Organ allocation policy is primarily based on disease severity instead of waiting time. Transplant surgery usually involves resection of the whole liver, in situ implantation with reconstruction of the hepatic vein, the portal vein, the hepatic artery and the biliary duct in sequence. The primary goal of artificial immunosuppression is to prevent graft rejection, and the secondary one is to reduce its complication or side effects. Life-long oral nucleoside/nucleotide analogues against hepatitis virus B is needed while short course of direct acting agents against hepatitis viral C is enough to eradicate the virus. Basic understanding of the underlying rationales will help students prepare for advanced learning and cope with the recipients confidently in the future.

The Current State of Liver Transplantation in the United States: Perspective From American Society of Transplant Surgeons (ASTS) Scientific Studies Committee and Endorsed by ASTS Council

This article is a review of the salient points and a future prospective based on the 2014 Organ Procurement and Transplantation Network (OPTN)/Scientific Registry of Transplant Recipients (SRTR) liver donation and transplantation data report recently published by the American Journal of Transplantation. Emphasis of our commentary and interpretation is placed on data relating to waitlist dynamics, organ utilization rates, the impact of recent advances in the treatment of hepatitis C, and the increases in end-stage renal disease among liver transplant candidates. Finally, we share our vision on potential areas of innovation that are likely to significantly improve the field of liver transplantation in the near future.