Heterogeneity and disparities in the use of exception scores in pediatric liver allocation

Access to and Health Outcomes of Pediatric Solid Organ Transplantation for Indigenous Children in 4 Settler-colonial Countries: A Scoping Review

Solid organ transplantation (SOT) is considered the optimal treatment for children with end-stage organ failure; however, increased efforts are needed to understand the gap surrounding equitable access to and health outcomes of SOT for Indigenous children. This scoping review summarizes the literature on the characteristics of access to and health outcomes of pediatric SOT among Indigenous children in the settler-colonial states of Canada, Aotearoa New Zealand, Australia, and the United States. A search was performed on MEDLINE, EMBASE, PsycINFO, and CINAHL for studies matching preestablished eligibility criteria from inception to November 2021. A preliminary gray literature search was also conducted. Twenty-four studies published between 1996 and 2021 were included. Studies addressed Indigenous pediatric populations within the United States (n = 7), Canada (n = 6), Aotearoa New Zealand (n = 5), Australia (n = 5), and Aotearoa New Zealand and Australia combined (n = 1). Findings showed that Indigenous children experienced longer time on dialysis, lower rates of preemptive and living donor kidney transplantation, and disparities in patient and graft outcomes after kidney transplantation. There were mixed findings about access to liver transplantation for Indigenous children and comparable findings for graft and patient outcomes after liver transplantation. Social determinants of health, such as geographic remoteness, lack of living donors, and traditional spiritual beliefs, may affect SOT access and outcomes for Indigenous children. Evidence gaps emphasize the need for action-based initiatives within SOT that prioritize research with and for Indigenous pediatric populations. Future research should include community-engaged methodologies, situated within local community contexts, to inform culturally safe care for Indigenous children.

Distinct effects of racial and socioeconomic disparities on biliary atresia diagnosis and outcome

OBJECTIVES

To identify and distinguish between racial and socioeconomic disparities in age at hepatology care, diagnosis, access to surgical therapy, and liver transplant-free survival in patients with biliary atresia (BA).

METHODS

Single-center retrospective cohort study of 69 BA patients from 2010 to 2021. Patients were grouped into White and non-White cohorts. The socioeconomic milieu was analyzed utilizing neighborhood deprivation index, a census tract-based calculation of six socioeconomic variables. The primary outcomes of this study were timing of the first hepatology encounter, surgical treatment with hepatic portoenterostomy (HPE), and survival with native liver (SNL) at 2 years.

RESULTS

Patients were 55% male and 72% White. White patients were referred at a median of 34 days (interquartile range [IQR]: 17-65) vs. 67 days (IQR: 42-133; p = 0.001) in non-White patients. White infants were more likely to undergo HPE (42/50 patients; 84%) compared to non-White (10/19; 53%), odds ratio (OR) 4.73 (95% confidence interval: 1.46-15.31; p = 0.01). Independent of race, patients exposed to increased neighborhood-level deprivation were less likely to receive HPE (OR: 0.49, p = 0.04) and achieve SNL (OR: 0.54, p = 0.02).

CONCLUSIONS

Racial and socioeconomic disparities are independently associated with timely BA diagnosis, access to surgical treatment, and transplant-free survival. Public health approaches to improve screening for pathologic jaundice in infants of diverse racial backgrounds and to test and implement interventions for socioeconomically at-risk families are needed.

The impact of socioeconomic deprivation on liver transplantation

Despite global expansion, social disparities impact all phases of liver transplantation, from patient referral to post-transplant care. In pediatric populations, socioeconomic deprivation is associated with delayed referral, higher waitlist mortality, and reduced access to living donor transplantation. Children from socially deprived communities are twice as much less adherent to immunosuppression and have up to a 32% increased incidence of graft failure. Similarly, adult patients from deprived areas and racial minorities have a higher risk of not initiating the transplant evaluation, lower rates of waitlisting, and a 6% higher risk of not being transplanted. Social deprivation is racially segregated, and Black recipients have an increased risk of post-transplant mortality by up to 21%. The mechanisms linking social deprivation to inferior outcomes are not entirely elucidated, and powered studies are still lacking. We offer a review of the most recent evidence linking social deprivation and post-liver transplant outcomes in pediatric and adult populations, as well as a literature-derived theoretical background model for future research on this topic.

Child Health Needs and the Pediatric Gastroenterology Workforce: 2020-2040

This article is part of an American Board of Pediatrics Foundation-sponsored effort to analyze and forecast the pediatric subspecialty workforce between 2020 and 2040. Herein, an overview of the current pediatric gastroenterology workforce is provided, including demographics, work characteristics, and geographic distribution of practitioners. Brief context is provided on the changing nature of current practice models and the increasing prevalence of some commonly seen disorders. On the basis of a rigorous microsimulation workforce projection model, projected changes from 2020 to 2040 in the number of pediatric gastroenterologists and clinical workforce equivalents in the United States are presented. The article closes with a brief discussion of training, clinical practice, policy, and future workforce research implications of the data presented. This data-driven analysis suggests that the field of pediatric gastroenterology will continue to grow in scope and complexity, propelled by scientific advances and the increasing prevalence of many disorders relevant to the discipline. The workforce is projected to double by 2040, a growth rate faster than most other pediatric subspecialties. Disparities in care related to geography, race, and ethnicity are among the most significant challenges for the years ahead. Changes to training and education, incentives to meet the needs of underserved populations, and new multidisciplinary models for health care delivery will be necessary to optimally meet the volume, diversity, and complexity of children with gastroenterological diseases in the years ahead.

The Accuracy of Nonstandardized MELD/PELD Score Exceptions in the Pediatric Liver Allocation System

BACKGROUND

In the United States, over half of pediatric candidates receive exceptions and status upgrades that increase their allocation model of end-stage liver disease/pediatric end-stage liver disease (MELD/PELD) score above their laboratory MELD/PELD score. We determined whether these "nonstandardized" MELD/PELD exceptions accurately depict true pretransplant mortality risk.

METHODS

Using data from the Scientific Registry of Transplant Recipients, we identified pediatric candidates (<18 y of age) with chronic liver failure added to the waitlist between June 2016 and September 2021 and estimated all-cause pretransplant mortality with mixed-effects Cox proportional hazards models that treated allocation MELD/PELD and exception status as time-dependent covariates. We also estimated concordance statistics comparing the performance of laboratory MELD/PELD with allocation MELD/PELD. We then compared the proportion of candidates with exceptions before and after the establishment of the National Liver Review Board.

RESULTS

Out of 2026 pediatric candidates listed during our study period, 403 (19.9%) received an exception within a week of listing and 1182 (58.3%) received an exception before delisting. Candidates prioritized by their laboratory MELD/PELD scores had an almost 9 times greater risk of pretransplant mortality compared with candidates who received the same allocation score from an exception (hazard ratio 8.69; 95% confidence interval, 4.71-16.03; P < 0.001). The laboratory MELD/PELD score without exceptions was more accurate than the allocation MELD/PELD score with exceptions (Harrell's c-index 0.843 versus 0.763). The proportion of patients with an active exception at the time of transplant decreased significantly after the National Liver Review Board was implemented (67.4% versus 43.4%, P < 0.001).

CONCLUSIONS

Nonstandardized exceptions undermine the rank ordering of pediatric candidates with chronic liver failure.

Racial and socioeconomic disparities in status exceptions for pediatric heart transplant candidates under the current U.S. Pediatric Heart Allocation Policy

BACKGROUND

The 2016 revision of the US Pediatric Heart Allocation Policy developed stringent rules for priority status creating impetus for clinicians to seek status exceptions. We hypothesized there may be differential status exceptions based on race and socioeconomic status (SES) contributing to disparities in waitlist outcomes.

METHODS

The Scientific Registry for Transplant Recipients was queried for children listed for heart transplant from 2012 to 2020. Waitlist status & mortality with regards to race and neighborhood SES were stratified by listing before (Era 1) or after (Era 2) the policy change.

RESULTS

The use of both 1A and 1B exceptions (E) increased in Era 2. In Era 1, there was no association between patient race or neighborhood SES on use of 1A(E) or 1B(E) when controlling for age and diagnosis. In Era 2, neither race nor neighborhood SES were associated with 1A(E), but both were associated with 1B(E): non-Hispanic (NH) Black children and those from low- and middle-SES neighborhoods were significantly less likely to be listed 1B(E). In Era 1, there were no significant differences in waitlist mortality based on race at any waitlist status; in Era 2, NH Black children had higher waitlist mortality when initially listed 1B or 2.

CONCLUSIONS

Since the 2016 policy change, racial disparities in waitlist mortality have worsened among children initially listed with lower priority status. Unequal use of 1B exceptions, which lower waitlist mortality, may explain some of these disparities. Recently implemented standardized pediatric exception guidance has the potential to improve equity.

An Ethical Analysis of Obesity as a Contraindication to Pediatric Liver Transplant Candidacy

Childhood obesity is becoming more prevalent in the United States (U.S.) and worldwide, including among children in need of liver transplant. Unlike with heart and kidney failure, end stage liver disease (ESLD) is unique in that no widely available medical technology can re-create the life-sustaining function a failing liver. Therefore, delaying life-saving liver transplant for weight loss, for example, is much harder, if not impossible for many pediatric patients, especially those with acute liver failure. For adults in the U.S., guidelines consider obesity a contraindication to liver transplant. While formal guidelines are lacking in children, many pediatric transplant centers also consider obesity a contraindication to pediatric liver transplant. Variations in practice among pediatric institutions may result in biased and ad hoc decisions that worsen health care inequities. In this paper we define and report the prevalence of childhood obesity among children with ESLD, 2) review existing guidelines for liver transplant in adults with obesity, 3) examine pediatric liver transplant outcomes and 4) discuss the ethical considerations of utilizing obesity as a contraindication to pediatric liver transplant informed by the principles of utility, justice and respect for persons.

Can non-directed living liver donation help improve access to grafts and correct socioeconomic disparities in pediatric liver transplantation?

BACKGROUND

Each year, children die awaiting LT as the demand for grafts exceeds the available supply. Candidates with public health insurance are significantly less likely to undergo both deceased donor LT and D-LLD LT. ND-LLD is another option to gain access to a graft. The aim of this study was to evaluate if recipient insurance type is associated with likelihood of D-LLD versus ND-LLD LT.

METHODS

The SRTR/OPTN database was reviewed for pediatric LDLT performed between January 1, 2014 (Medicaid expansion era) and December 31, 2019 at centers that performed ≥1 ND-LLD LDLT during the study period. A multivariable logistic regression was performed to assess relationship between type of living donor (directed vs. non-directed) and recipient insurance.

RESULTS

Of 299 pediatric LDLT, 46 (15%) were from ND-LLD performed at 18 transplant centers. Fifty-nine percent of ND-LLD recipients had public insurance in comparison to 40% of D-LLD recipients (p = .02). Public insurance was associated with greater odds of ND-LLD in comparison to D-LLD upon multivariable logistic regression (OR 2.37, 95% CI 1.23-4.58, p = .01).

CONCLUSIONS

ND-LLD allows additional children to receive LTs and may help address some of the socioeconomic disparity in pediatric LDLT, but currently account for only a minority of LDLT and are only performed at a few institutions. Initiatives to improve access to both D-LLD and ND-LLD transplants are needed.

A systematic review of social determinants of health in pediatric organ transplant outcomes

BACKGROUND

Equitable access to pediatric organ transplantation is critical, although risk factors negatively impacting pre- and post-transplant outcomes remain. No synthesis of the literature on SDoH within the pediatric organ transplant population has been conducted; thus, the current systematic review summarizes findings to date assessing SDoH in the evaluation, listing, and post-transplant periods.

METHODS

Literature searches were conducted in Web of Science, Embase, PubMed, and Cumulative Index to Nursing and Allied Health Literature databases.

RESULTS

Ninety-three studies were included based on pre-established criteria and were reviewed for main findings and study quality. Findings consistently demonstrated disparities in key transplant outcomes based on racial or ethnic identity, including timing and likelihood of transplant, and rates of rejection, graft failure, and mortality. Although less frequently assessed, variations in outcomes based on geography were also noted, while findings related to insurance or SES were inconsistent.

CONCLUSION

This review underscores the persistence of SDoH and disparity in equitable transplant outcomes and discusses the importance of individual and systems-level change to reduce such disparities.

Deceased donor organ allocation in pediatric transplantation: A historical narrative

BACKGROUND

Since the earliest clinical successes in solid organ transplantation, the proper method of organ allocation for children has been a contentious subject. Over the past 30-35 years, the medical and social establishments of various countries have favored some degree of preference for children on the respective waiting lists. However, the specific policies to accomplish this have varied widely and changed frequently between organ type and country.

METHODS

Organ allocation policies over time were examined. This review traces the reasons behind and the measures/principles put in place to promote early deceased donor transplantation in children.

RESULTS

Preferred allocation in children has been approached in a variety of ways and with varying degrees of commitment in different solid organ transplant disciplines and national medical systems.

CONCLUSION

The success of policies to advantage children has varied significantly by both organ and medical system. Further work is needed to optimize allocation strategies for pediatric candidates.

A review of racial, socioeconomic, and geographic disparities in pediatric liver transplantation

Equity is a core principle in both pediatrics and solid organ transplantation. Health inequities, specifically across race, socioeconomic position, or geography, reflect a moral failure. Ethical principles of prudential life span, maximin principle, and fair innings argue for allocation priority to children related to the number of life years gained, equal access to transplant, and equal opportunity for ideal posttransplant outcomes. Iterative policy changes have aimed to narrow these disparities to achieve pediatric transplant equity. These policy changes have focused on modifying pediatric priority for organ allocation to eliminate mortality on the pediatric transplant waiting list. Yet disparities remain in pediatric liver transplantation at all time points: from access to referral for transplantation, likelihood of living donor transplantation, use of exception narratives, waitlist mortality, and inequitable posttransplant outcomes. Black children are less likely to be petitioned for exception scores, have higher waitlist mortality, are less likely to be the recipient of a living donor transplant, and have worse posttransplant outcomes compared with White children. Children living in the most socioeconomically deprived neighborhoods have worse posttransplant outcomes. Children living farther from a transplant center have higher waitlist mortality. Herein we review the current knowledge of these racial and ethnic, socioeconomic, and geographic disparities for these children. To achieve equity, stakeholder engagement is required at all levels from providers and health delivery systems, learning networks, institutions, and society. Future initiatives must be swift, bold, and effective with the tripartite mission to inform policy changes, improve health care delivery, and optimize resource allocation to provide equitable transplant access, waitlist survival, and posttransplant outcomes for all children.

Pediatric Liver Transplantation

Liver transplantation (LT) for children results in excellent short- and long-term patient and graft survival. LT is a lifesaving procedure in children with acute or chronic liver disease, hepatic tumors, and select genetic metabolic diseases in which it can significantly improve quality of life. In this article, the authors discuss the unique aspects of pediatric LT, including the indications, appropriate patient selection and evaluation, allocation of organs, transplant surgery including the use of variant grafts, posttransplant care including immunosuppression management, prognosis, and transition of care.

Decreased access to pediatric liver transplantation during the COVID-19 pandemic

BACKGROUND

The COVID-19 pandemic has affected all aspects of the US healthcare system, including liver transplantation. The objective of this study was to understand national changes to pediatric liver transplantation during COVID-19.

METHODS

Using SRTR data, we compared waitlist additions, removals, and liver transplantations for pre-COVID-19 (March-November 2016-2019), early COVID-19 (March-May 2020), and late COVID-19 (June-November 2020).

RESULTS

Waitlist additions decreased by 25% during early COVID-19 (41.3/month vs. 55.4/month, p < .001) with black candidates most affected (p = .04). Children spent longer on the waitlist during early COVID-19 compared to pre-COVID-19 (140 vs. 96 days, p < .001). There was a 38% decrease in liver transplantations during early COVID-19 (IRR 0.62, 95% CI 0.49-0.78), recovering to pre-pandemic rates during late COVID-19 (IRR 1.03, NS), and no change in percentage of living and deceased donors. White children had a 30% decrease in overall liver transplantation but no change in living donor liver transplantation (IRR 0.7, 95% CI 0.50-0.95; IRR 0.96, NS), while non-white children had a 44% decrease in overall liver transplantation (IRR 0.56, 95% CI 0.40-0.77) and 81% decrease in living donor liver transplantation (IRR 0.19, 95% CI 0.02-0.76).

CONCLUSIONS

The COVID-19 pandemic decreased access to pediatric liver transplantation, particularly in its early stage. There were no regional differences in liver transplantation during COVID-19 despite the increased national sharing of organs. While pediatric liver transplantation has resumed pre-pandemic levels, ongoing racial disparities must be addressed.

Racial/ethnic disparities in wait-list outcomes are only partly explained by socioeconomic deprivation among children awaiting liver transplantation

BACKGROUND AND AIMS

Racial/ethnic minority children have worse liver transplant (LT) outcomes. We evaluated whether neighborhood socioeconomic deprivation affected associations between race/ethnicity and wait-list mortality.

APPROACH AND RESULTS

We included children (age <18) listed 2005-2015 in the Scientific Registry of Transplant Recipients. We categorized patients as non-Hispanic White, Black, Hispanic, and other. We matched patient ZIP codes to a neighborhood socioeconomic deprivation index (range, 0-1; higher values indicate worse deprivation). Primary outcomes were wait-list mortality, defined as death/delisting for too sick, and receipt of living donor liver transplant (LDLT). Competing risk analyses modeled the association between race/ethnicity and wait-list mortality, with deceased donor liver transplant (DDLT) and LDLT as competing risks, and race/ethnicity and LDLT, with wait-list mortality and DDLT as competing risks. Of 7716 children, 17% and 24% identified as Black and Hispanic, respectively. Compared to White children, Black and Hispanic children had increased unadjusted hazard of wait-list mortality (subhazard ratio [sHR], 1.44; 95% CI, 1.18, 1.75 and sHR, 1.48; 95% CI, 1.25, 1.76, respectively). After adjusting for neighborhood deprivation, insurance, and listing laboratory Model for End-Stage Liver Disease/Pediatric End-Stage Liver Disease, Black and Hispanic children did not have increased hazard of wait-list mortality (sHR, 1.12; 95% CI, 0.91, 1.39 and sHR, 1.21; 95% CI, 1.00, 1.47, respectively). Similarly, Black and Hispanic children had a decreased likelihood of LDLT (sHR, 0.58; 95% CI, 0.45, 0.75 and sHR, 0.61; 95% CI, 0.49, 0.75, respectively). Adjustment attenuated the effect of Black and Hispanic race/ethnicity on likelihood of LDLT (sHR, 0.79; 95% CI, 0.60, 1.02 and sHR, 0.89; 95% CI, 0.70, 1.11, respectively).

CONCLUSIONS

Household and neighborhood socioeconomic factors and disease severity at wait-list entry help explain racial/ethnic disparities for children awaiting transplant. A nuanced understanding of how social adversity contributes to wait-list outcomes may inform strategies to improve outcomes.

Liver simulated allocation model does not effectively predict organ offer decisions for pediatric liver transplant candidates

The SRTR maintains the liver-simulated allocation model (LSAM), a tool for estimating the impact of changes to liver allocation policy. Integral to LSAM is a model that predicts the decision to accept or decline a liver for transplant. LSAM implicitly assumes these decisions are made identically for adult and pediatric liver transplant (LT) candidates, which has not been previously validated. We applied LSAM's decision-making models to SRTR offer data from 2013 to 2016 to determine its efficacy for adult (≥18) and pediatric (<18) LT candidates, and pediatric subpopulations-teenagers (≥12 to <18), children (≥2 to <12), and infants (<2)-using the area under the receiver operating characteristic (ROC) curve (AUC). For nonstatus 1A candidates, all pediatric subgroups had higher rates of offer acceptance than adults. For non-1A candidates, LSAM's model performed substantially worse for pediatric candidates than adults (AUC 0.815 vs. 0.922); model performance decreased with age (AUC 0.898, 0.806, 0.783 for teenagers, children, and infants, respectively). For status 1A candidates, LSAM also performed worse for pediatric than adult candidates (AUC 0.711 vs. 0.779), especially for infants (AUC 0.618). To ensure pediatric candidates are not unpredictably or negatively impacted by allocation policy changes, we must explicitly account for pediatric-specific decision making in LSAM.

Adult Liver Disease Prognostic Modelling for Long-term Outcomes in Biliary Atresia: An Observational Cohort Study

OBJECTIVES

To assess the utility of prognostic scoring systems for adolescents with biliary atresia (BA) surviving with native liver, for predicting the subsequent requirement for liver transplantation (LT).

METHODS

Single-centre retrospective analysis of 397 BA patients who received Kasai Portoenterostomy (KP) 1980-1996 and survived with the native liver at 16 years. Laboratory and clinical variables at 16 years (timepoint 16 years) were used to calculate (i) LT allocation scores; Model for End-Stage Liver Disease [MELD/MELD-sodium (Na)], and UK End-Stage Liver Disease (UKELD); (ii) Mayo Primary Sclerosing Cholangitis risk score (MayoPSC) and (iii) a modified Paediatric End-Stage Liver Disease (PELD) score. Scores were compared between patients requiring LT after 16 years of age (LT > 16 years), and those who survived with native liver, at the latest follow-up. Additional subgroup analysis for patients with data available at 12 years (timepoint 12 years).

RESULTS

MELD (area under the receiver operating characteristic [AUROC] 0.847) and UKELD (AUROC: 0.815) at 16 years of age predict the need for LT > 16 years. No advantage for MELD-Na over MELD was demonstrated. MELD >8.5 and UKELD >47 predicted LT > 16 years with 84% and 79% sensitivity and 73% and 73% specificity. PELD had a similar performance to MELD, but superiority to UKELD. MayoPSC revealed predictive accuracy for LT >16 years (AUROC 0.859), with a score of >0.87 predicting LT > 16 years with 85% sensitivity and 82% specificity. At timepoint 12 years, MELD and MayoPSC predicted LT >16 years. Change in MELD, PELD and MayoPSC between 12 and 16 years of age, was associated with LT >16 years.

CONCLUSIONS

Adult LT allocation scores may help monitor progress in adolescent BA, but the omission of relevant risk factors limits their utility for listing in this cohort. A BA-specific prognostic score would improve the management of adolescent BA.

Internal split liver transplants reduce the waiting list time for teenagers with a low calculated Model for End-stage Liver Disease score

BACKGROUND

Split liver transplantation allows for the simultaneous transplantation of two patients, typically a child and an adult, with a single organ. We report our experience with "internal splits" in which 10 pediatric patients from our institution were transplanted with five organs. We hypothesized that this would reduce the WL time for teenagers with a low calculated MELD score.

METHODS

A retrospective chart review of those 10 patients was done. Their WL time was compared with local, regional, and national data. P < .05 was considered significant.

RESULTS

The median age of the five primary recipients to whom the liver was first allocated was 2.3 years (0.7-7.4) (median weight 10.4 kg (8.4-17.7)). They received a segment 2-3 graft. Five "secondary" recipients (median age 17.4 years (16.6-18.9); median weight 66.2 kg (53.7-70.0)) were identified on our WL to receive the trisector graft. At transplant, their median calculated MELD score was 11 (8-20). Their mean WL time (241.6 ± 218.9 days) was significantly shorter than local (480.6 ± 833.6 days), regional (370.4 ± 563.4 days), and national patients (245.6 ± 465.4 days) with MELD ≤ 20 (P = .047). There was no significant difference between their WL time and that of patients with a MELD 8 ≤ x≤31 (equivalent to their median exception score, P = .63). Patient and graft survival was 100% for all 10 patients.

CONCLUSION

In our experience, simultaneous internal split liver transplantation allowed teenagers with a low calculated MELD score to be transplanted faster than patients with a similar score. Promoting the use of internal split liver transplantation could help reduce the pediatric waitlist mortality.

A Learning Health System for Pediatric Liver Transplant: The Starzl Network for Excellence in Pediatric Transplantation

OBJECTIVE

Learning health systems (LHS) integrate research, improvement, management, and patient care, such that every child receives "the right care at the right time...every time," that is, evidence-based, personalized medicine. Here, we report our efforts to establish a sustainable, productive, multicenter LHS focused on pediatric liver transplantation.

METHODS

The Starzl Network for Excellence in Pediatric Transplantation (SNEPT) is the first multicenter effort by pediatric liver transplant families and providers to develop shared priorities and a shared agenda for innovation in clinical care. This report outlines SNEPT's structure, accomplishments, and challenges as an LHS.

RESULTS

We prioritized 4 initial projects: immunosuppression, perioperative anticoagulation, quality of life, and transition of care. We shared center protocols/management to identify areas of practice variability between centers. We prioritized actionable items that address barriers to providing "the right care at the right time" to every pediatric liver transplant recipient: facilitating transparency of practice variation and the connection of practices to patient outcomes, harnessing existing datasets to reduce the burden of tracking outcomes, incorporating patient-reported outcomes into outcome metrics, and accelerating the implementation of knowledge into clinical practice. This has allowed us to strengthen collaborative relationships, design quality improvement projects, and collect pilot data for each of our priority projects.

CONCLUSIONS

The field of pediatric liver transplantation can be advanced through application of LHS principles. Going forward, SNEPT will continue to unite patient advocacy, big data, technology, and transplant thought leaders to deliver the best care, while developing new, scalable solutions to pediatric transplantation's most challenging problems.

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 the Pediatric End-Stage Liver Disease (PELD) growth failure thresholds on mortality among pediatric liver transplant candidates

The Pediatric End-Stage Liver Disease (PELD) score is intended to determine priority for children awaiting liver transplantation. This study examines the impact of PELD's incorporation of "growth failure" as a threshold variable, defined as having weight or height <2 standard deviations below the age and gender norm (z-score <2). First, we demonstrate the "growth failure gap" created by PELD's current calculation methods, in which children have z-scores <2 but do not meet PELD's growth failure criteria and thus lose 6-7 PELD points. Second, we utilized United Network for Organ Sharing (UNOS) data to investigate the impact of this "growth failure gap." Among 3291 pediatric liver transplant candidates, 26% met PELD-defined growth failure, and 17% fell in the growth failure gap. Children in the growth failure gap had a higher risk of waitlist mortality than those without growth failure (adjusted subhazard ratio [SHR] 1.78, 95% confidence interval [95% CI] 1.05-3.02, P = .03). They also had a higher risk of posttransplant mortality (adjusted HR 1.55, 95% CI 1.03-2.32, P = .03). For children without PELD exception points (n = 1291), waitlist mortality risk nearly tripled for those in the gap (SHR 2.89, 95% CI 1.39-6.01, P = .005). Current methods for determining growth failure in PELD disadvantage candidates arbitrarily and increase their waitlist mortality risk. PELD should be revised to correct this disparity.

Predicting ideal outcome after pediatric liver transplantation: An exploratory study using machine learning analyses to leverage Studies of Pediatric Liver Transplantation Data

Machine learning analyses allow for the consideration of numerous variables in order to accommodate complex relationships that would not otherwise be apparent in traditional statistical methods to better classify patient risk. The SPLIT registry data were analyzed to determine whether baseline demographic factors and clinical/biochemical factors in the first-year post-transplant could predict ideal outcome at 3 years (IO-3) after LT. Participants who received their first, isolated LT between 2002 and 2006 and had follow-up data 3 years post-LT were included. IO-3 was defined as alive at 3 years, normal ALT (<50) or GGT (<50), normal GFR, no non-liver transplants, no cytopenias, and no PTLD. Heat map analysis and RFA were used to characterize the impact of baseline and 1-year factors on IO-3. 887/1482 SPLIT participants met inclusion criteria; 334 had IO-3. Demographic, biochemical, and clinical variables did not elucidate a visual signal on heat map analysis. RFA identified non-white race (vs white race), increased length of operation, vascular and biliary complications within 30 days, and duct-to-duct biliary anastomosis to be negatively associated with IO-3. UNOS regions 2 and 5 were also identified as important factors. RFA had an accuracy rate of 0.71 (95% CI: 0.68-0.74), PPV = 0.83, and NPV = 0.70. RFA identified participant variables that predicted IO-3. These findings may allow for better risk stratification and personalization of care following pediatric liver transplantation.

Barriers to ideal outcomes after pediatric liver transplantation

Long-term survival for children who undergo LT is now the rule rather than the exception. However, a focus on the outcome of patient or graft survival rates alone provides an incomplete and limited view of life for patients who undergo LT as an infant, child, or teen. The paradigm has now appropriately shifted to opportunities focused on our overarching goals of "surviving and thriving" with long-term allograft health, freedom of complications from long-term immunosuppression, self-reported well-being, and global functional health. Experts within the liver transplant community highlight clinical gaps and potential barriers at each of the pretransplant, intra-operative, early-, medium-, and long-term post-transplant stages toward these broader mandates. Strategies including clinical research, innovation, and quality improvement targeting both traditional as well as PRO are outlined and, if successfully leveraged and conducted, would improve outcomes for recipients of pediatric LT.

A learning health network for pediatric liver transplantation: Inaugural meeting report from the Starzl Network for Excellence in Pediatric Transplantation

Learning Health Networks (LHN) improve the well-being of populations by aligning clinical care specialists, technology experts, patients and patient advocates, and other thought leaders for continuous improvement and seamless care delivery. A novel LHN focused on pediatric transplantation, the Starzl Network for Excellence in Pediatric Transplantation (SNEPT), convened its inaugural meeting in September 2018. Clinical care team representatives, patients, and patient families/advocates partnered to take part in educational sessions, pain point exercises, and project identification workshops. Participants discussed the global impact of transplant from both a population and individual perspective, identifying challenges and opportunities where the Starzl Network could work to improve outcomes at scale across a variety of transplant-related conditions.

Central line-associated bloodstream infection among children with biliary atresia listed for liver transplantation

BACKGROUND

Pre-transplant nutrition is a key driver of outcomes following liver transplantation in children. Patients with biliary atresia (BA) may have difficulty achieving satisfactory weight gain with enteral nutrition alone, and parenteral nutrition (PN) may be indicated. While PN has been shown to improve anthropometric parameters of children with BA listed for liver transplantation, less is known about the risks, particularly infectious, associated with this therapy among this specific group of patients.

AIM

To describe the incidence, microbiology, and risk factors of central line-associated bloodstream infection (CLABSI) among children with BA listed for liver transplantation.

METHODS

Retrospective review of children aged ≤ 2-years of age with BA who were listed for primary liver transplantation at Texas Children’s Hospital from 2008 through 2015 (n = 96). Patients with a central line for administration of PN (n = 63) were identified and details of each CLABSI event were abstracted. We compared the group of patients who experienced CLABSI to the group who did not, to determine whether demographic, clinical, or laboratory factors correlated with development of CLABSI.

RESULTS

Nineteen of 63 patients (30%, 95%CI: 19, 43) experienced 29 episodes of CLABSI during 4800 line days (6.04 CLABSI per 1000 line days). CLABSI was predominantly associated with Gram-negative organisms (14/29 episodes, 48%) including Klebsiella spp., Enterobacter spp., and Escherichia coli. The sole polymicrobial infection grew Enterobacter cloacae and Klebsiella pneumoniae. Gram-positive organisms (all Staphylococcus spp.) and fungus (all Candida spp.) comprised 9/29 (31%) and 6/29 (21%) episodes, respectively. No demographic, clinical, or laboratory factors were significantly associated with an increased risk for the first CLABSI event in Cox proportional hazards regression analysis

CONCLUSION

There is substantial risk for CLABSI among children with BA listed for liver transplantation. No clinical, demographic, or laboratory factor we tested emerged as an independent predictor of CLABSI. While our data did not show an impact of CLABSI on the short-term clinical outcome, it would seem prudent to implement CLABSI reduction strategies in this population to the extent that each CLABSI event represents potentially preventable hospitalization, unnecessary healthcare dollar expenditures, and may exact an opportunity cost, in terms of missed allograft offers.

Liver Transplantation in Children

Liver transplantation (LT) for children has excellent short- and long-term patient and graft survival. LT is a lifesaving procedure in children with acute or chronic liver disease, hepatic tumors, and a few genetic metabolic diseases in which it can significantly improve quality of life. In this article, the authors discuss the unique aspects of pediatric LT, including the indications, patient selection and evaluation, allocation, transplant surgery and organ selection, posttransplant care, prognosis, adherence, and transition of care.

Variability in acceptance of organ offers by pediatric transplant centers and its impact on wait-list mortality

Recent data have suggested that pediatric patients wait-listed for a liver transplantation frequently have liver offers declined. However, factors associated with liver offer decisions and center-level variability in practice patterns have not been explored. We evaluated United Network for Organ Sharing data on all match runs from May 1, 2007 to December 31, 2015 in which the liver was offered to ≥1 pediatric patient; the transplant recipient was ranked in the first 40 positions for the organ offer; and the donor was brain-dead and <50 years of age. We used multilevel mixed effects models to evaluate factors associated with organ offer acceptance, among-center variability, and the association between center-level acceptance and wait-list mortality. There were 4088 unique pediatric patients during the study period, comprising 27,094 match runs. Initial Model for End-Stage Liver Disease or Pediatric End-Stage Liver Disease score, history of exception points, recipient region, rank on match run, and geographic share type were all associated with probability of offer acceptance. There was significant among-center variation (P < 0.001) in adjusted liver offer acceptance rates, accounting for donor, recipient, and match-related factors (adjusted acceptance rates: median, 8.9%; range, 5.1%-14.6%). Center-level acceptance rates were associated with wait-list mortality, with a >10% increase in the risk of wait-list mortality for every 1% decrease in a center's adjusted liver offer acceptance rate (odds ratio, 1.10; 95% confidence interval, 1.01-1.19). In conclusion, there is significant among-center variability in liver offer acceptance rates for pediatric patients that is not explained by donor and recipient factors. A center's liver acceptance behavior significantly impacts whether a pediatric patient will be transplanted or die on the waiting list. Liver Transplantation 24 803-809 2018 AASLD.

Impact of Race and Ethnicity on Outcomes for Children Waitlisted for Pediatric Liver Transplantation

OBJECTIVE

African Americans and other minorities are known to face barriers to health care influencing their access to organ transplantation but it is not known whether these barriers exist among pediatric liver transplant waitlist candidates. We sought to determine whether outcomes on the waitlist (ie, mortality, deceased donor liver transplantation [DDLT], and living-donor liver transplantation [LDLT]) varied by race/ethnicity.

METHODS

National registry data were studied to estimate the race/ethnicity-specific risk of waitlist mortality, DDLT and LDLT in children (<18 years) waitlisted between March 2002 and March 2015.

RESULTS

There was no evidence of racial/ethnic disparities in waitlist mortality. Compared to Caucasians, LDLT varied by race/ethnicity, with only 6.7% African Americans and 10.3% Hispanic children receiving LDLT compared with 12.4% Caucasian, 13.3% Asian, and 9.4% mix/other children. In an adjusted Cox proportional hazards model, African Americans were half as likely as Caucasians to use LDLT (hazard ratio [HR]: 0.410.550.73) but had similar use of DDLT (HR: 0.981.061.16). In a model that considered mortality, DDLT, and LDLT as competing risks, African Americans had significantly reduced incidence of LDLT (subhazard ratio [sHR]: 0.410.560.75) compared to Caucasians, but increased use of DDLT (sHR: 1.061.161.26).

CONCLUSIONS

Compared to Caucasian children, African-American children are less likely to use LDLT but have higher rates of DDLT and similar survival on the waitlist. Additional research is necessary to understand the clinical and socioeconomic factors contributing to lower utilization of LDLT among African-American children awaiting transplantation.

Waiting list outcome of Peld/Meld exceptions: A single-center experience in Argentina

As PELD/MELD-based allocation policy was adopted in Argentina in 2005, a system of exception points has been in place in order to award increased waitlist priority to those patients whose severity of illness is not captured by the PELD/MELD score. We aimed to investigate the WL outcome of patients with granted PELD/MELD exceptions. A retrospective cohort study was conducted in children under 18 years old. WL outcomes were evaluated using univariable analysis. From 07/2005 to 01/2014, 408 children were listed for LT. There were 304 classified by calculated PELD/MELD. During this time, 85 (30%) PELD/MELD exceptions were granted. In this cohort, 89.4% (76 of 85) were transplanted and 7.1% (6 of 85) died while on the WL. The remaining 3 pts (3.5%) were removed from the WL due to other causes. We compared the impact of PELD/MELD exceptions in those 85 patients to outcomes in 87 non-exception patients with PELD/MELD ≥19 points. Patients with the exception had significantly better access to WL and lower WL mortality. Our data suggest that children listed by PELD/MELD exceptions had an advantage compared to children with CLD with equivalent PELD/MELD listing priorities.

Extubation in the operating room after pediatric liver transplant: A retrospective cohort study

BACKGROUND

Early extubation immediately following liver transplantation is increasingly common in adult practice. Some pediatric institutions have begun to adopt this strategy. Careful patient selection is essential in minimizing risk.

METHODS

This retrospective cohort study evaluated infants and children who underwent liver transplantation between July 2011 and December 2014. Our primary objective was to determine early extubation rate. Secondary objectives were to identify clinical factors associated with successful early extubation compared with delayed extubation and to examine significant postoperative complications, intensive care unit length of stay, and hospital length of stay.

RESULTS

The early extubation rate was 57.8% (37/64, confidence interval [CI] 44.8%-70.1%) over this 3.5-year period, increasing from 42% in 2012 to 58% by the end of 2014. The patients in the early extubation group were more likely to be older than the delayed extubation group (mean [SD], 7 [5.3] years vs 3.5 [5.5] years, difference between the mean [95% CI], 3.5 [0.8, 6.2] years); were to have come from home on the day of surgery (78.4% vs 25.9%); and were less likely to be listed as United Network for Organ Sharing status 1A (2.7% vs 25.9%). The early extubation group received less packed red blood cell volume (mean [SD], 9 [13.2] mL/kg vs 40.6 [48.5] mL/kg, difference between the mean [95% CI], 31.6 [95% CI 14.9, 48.3] mL/kg) and fresh-frozen plasma (mean 2.7 [SD 9.5] vs 13.3 [SD15.1], difference between the mean [95% CI], 10.5 [4.4,16.7] mL/kg). None of the patients in the early extubation group required reintubation in the first 24 hours following transplant and none experienced hepatic artery thrombosis. The early extubation group had a shorter average postoperative PICU stay (mean 3.8 [SD 2.1] days vs 17.6 [SD 31.3] days, difference between the mean [95% CI], 9.5 [4.3, 14.7] days) and a shorter postoperative hospital stay overall (mean 10.7 [SD 4.3] days vs 29.7 [SD 43.1] days, difference between the mean [95% CI], 19.1 [8.6, 29.6] days).

CONCLUSION

More than half of our pediatric liver transplant patients were successfully extubated in the operating room immediately following surgery. We believe early extubation to be safe when employed in selected subpopulations of pediatric patients undergoing liver transplantation.

Disparities in Waitlist and Posttransplantation Outcomes in Liver Transplant Registrants and Recipients Aged 18 to 24 Years: Analysis of the UNOS Database

BACKGROUND

We evaluated liver transplantation waitlist and posttransplantation outcomes in those aged 18 to 24 years compared with both younger (0-17 years) and older (25-34 years) registrants and recipients.

METHODS

Using national data from the United Network for Organ Sharing, competing risk, Cox regression and Kaplan-Meier analyses were performed on first-time liver transplant registrants (n = 13 979) and recipients (n = 8718) ages 0 to 34 years between 2002 and 2015.

RESULTS

Nonstatus 1A registrants, registrants aged 0 to 17 and 25 to 34 years were less likely to experience dropout from the waiting list compared with those aged 18 to 24 years (adjusted hazard ratio, 0-5 years = 0.36; 6-11 = 0.29; 12-17 = 0.48; 18-24 = 1.00; 25-34 = 0.82). Although there was no difference in risk of graft failure across all age groups, both younger and older age groups had significantly lower risk of posttransplant mortality compared with those aged 18 to 24 years (adjusted hazard ratio, for 0-5 years = 0.53, 6-11 = 0.48, 12-17 = 0.70, 18-24 = 1.00, 25-34 = 0.77). This may be related to lower likelihood of retransplantation after graft failure in those aged 18 to 24 years.

CONCLUSIONS

This national registry study demonstrates for the first time poorer waitlist and postliver transplant outcomes in young adults ages 18 to 24 years at the time of listing and transplantation compared to older and younger age groups. Given the potential survival benefit in transplanting young adults and the shortage of solid organs for transplant, future studies are critical to identify and target modifiable risk factors to improve waitlist and long-term posttransplant outcomes in 18- to 24-year-old registrants and recipients.

Justifying Nonstandard Exception Requests for Pediatric Liver Transplant Candidates: An Analysis of Narratives Submitted to the United Network for Organ Sharing, 2009-2014

Nonstandard exception requests (NSERs), for which transplant centers provide patient-specific narratives to support a higher Model for End-stage Liver Disease/Pediatric End-stage Liver Disease score, are made for >30% of pediatric liver transplant candidates. We describe the justifications used in pediatric NSER narratives 2009-2014 and identify justifications associated with NSER denial, waitlist mortality, and transplant. Using United Network for Organ Sharing data, 1272 NSER narratives from 1138 children with NSERs were coded for analysis. The most common NSER justifications were failure-to-thrive (48%) and risk of death (40%); both associated with approval. Varices, involvement of another organ, impaired quality of life, and encephalopathy were justifications used more often in denied NSERs. Of the 25 most prevalent justifications, 60% were not associated with approval or denial. Waitlist mortality risk was increased when fluid overload or "posttransplant complication outside standard criteria" were cited and decreased when liver-related infection was noted. Transplant probability was increased when the narrative mentioned liver-related infections, and fluid overload for children <2 years old; it decreased when "posttransplant complications outside standard criteria" and primary sclerosing cholangitis were cited. This analysis provides novel insight and suggests targets for future consideration in outcomes research and exception criteria. Changes in the allocation system are needed to ensure equity and optimize outcomes for all pediatric candidates.

Pediatric Liver Transplantation: Unique Concerns for the Critical Care Team

Liver transplantation originated in children more than 50 years ago, and these youngest patients, while comprising the minority of liver transplant recipients nationwide, can have some of the best and most rewarding outcomes. The indications for liver transplantation in children are generally more diverse than those seen in adult patients. This diversity in underlying cause of disease brings with it increased complexity for all who care for these patients. Children, still being completely dependent on others for survival, also require a care team that is able and ready to work with parents and family in addition to the patient at the center of the process. In this review, we aim to discuss diagnoses of particular uniqueness or importance to pediatric liver transplantation. We also discuss the evaluation of a pediatric patient for liver transplant, the system for allocating them a new liver, and also touch on postoperative concerns that are unique to the pediatric population.

Changes in Utilization and Discard of Hepatitis C-Infected Donor Livers in the Recent Era

The impact of interferon (IFN)-free direct-acting antiviral (DAA) hepatitis C virus (HCV) treatments on utilization and outcomes associated with HCV-positive deceased donor liver transplantation (DDLT) is largely unknown. Using the Scientific Registry of Transplant Recipients, we identified 25 566 HCV-positive DDLT recipients from 2005 to 2015 and compared practices according to the introduction of DAA therapies using modified Poisson regression. The proportion of HCV-positive recipients who received HCV-positive livers increased from 6.9% in 2010 to 16.9% in 2015. HCV-positive recipients were 61% more likely to receive an HCV-positive liver after 2010 (early DAA/IFN era) (aRR:_1.45 1.61_1.79 , p < 0.001) and almost three times more likely to receive one after 2013 (IFN-free DAA era) (aRR:_2.58 2.85_3.16 , p < 0.001). Compared to HCV-negative livers, HCV-positive livers were 3 times more likely to be discarded from 2005 to 2010 (aRR:_2.69 2.99_3.34 , p < 0.001), 2.2 times more likely after 2010 (aRR:_1.80 2.16_2.58 , p < 0.001) and 1.7 times more likely after 2013 (aRR:_1.37 1.68_2.04 , p < 0.001). Donor HCV status was not associated with increased risk of all-cause graft loss (p = 0.1), and this did not change over time (p = 0.8). Use of HCV-positive livers has increased dramatically, coinciding with the advent of DAAs. However, the discard rate remains nearly double that of HCV-negative livers. Further optimization of HCV-positive liver utilization is necessary to improve access for all candidates.

Global lessons in graft type and pediatric liver allocation: A path toward improving outcomes and eliminating wait-list mortality

Current literature and policy in pediatric liver allocation and organ procurement are reviewed here in narrative fashion, highlighting historical context, ethical framework, technical/procurement considerations, and support for a logical way forward to an equitable pediatric liver allocation system that will improve pediatric wait-list and posttransplant outcomes without adversely affecting adults. Where available, varying examples of successful international pediatric liver allocation and split-liver policy will be compared to current US policy to highlight potential strategies that can be considered globally. Liver Transplantation 23:86-95 2017 AASLD.

Biliary atresia: Indications and timing of liver transplantation and optimization of pretransplant care

Biliary atresia (BA) is a progressive, fibro-obliterative disorder of the intrahepatic and extrahepatic bile ducts in infancy. The majority of affected children will eventually develop end-stage liver disease and require liver transplantation (LT). Indications for LT in BA include failed Kasai portoenterostomy, significant and recalcitrant malnutrition, recurrent cholangitis, and the progressive manifestations of portal hypertension. Extrahepatic complications of this disease, such as hepatopulmonary syndrome and portopulmonary hypertension, are also indications for LT. Optimal pretransplant management of these potentially life-threatening complications and maximizing nutrition and growth require the expertise of a multidisciplinary team with experience caring for BA. The timing of transplant for BA requires careful consideration of the potential risk of transplant versus the survival benefit at any given stage of disease. Children with BA often experience long wait times for transplant unless exception points are granted to reflect severity of disease. Family preparedness for this arduous process is therefore critical. Liver Transplantation 23:96-109 2017 AASLD.

Nonstandard Exception Requests Impact Outcomes for Pediatric Liver Transplant Candidates

Nonstandard exceptions requests (NSERs), in which transplant centers appeal on a case-by-case basis for Pediatric End-Stage Liver Disease/Mayo End-Stage Liver Disease points, have been highly utilized for pediatric liver transplant candidates. We evaluated whether NSE outcomes are associated with waitlist and posttransplant mortality. United Network for Organ Sharing (UNOS) Scientific Registry of Transplant Recipients data on pediatric liver transplant candidates listed in 2009-2014 were analyzed after excluding those granted automatic UNOS exceptions. Of 2581 pediatric waitlist candidates, 44% had an NSE request. Of the 1134 children with NSERs, 93% were approved and 7% were denied. For children 2-18 years at listing, NSER denial increased the risk of waitlist mortality or removal for being too sick (subhazard ratio 2.99, 95% confidence interval [CI] 1.26-7.07, p = 0.01 in multivariate analysis). For children younger than 2 years, NSER denial did not impact waitlist mortality/removal. Children with NSER approved had reduced risk of graft loss 3 years posttransplant in univariate but not multivariable analysis (odds ratio 0.73, 95% CI 0.53-1.01, p = 06). Those with NSER denial had a higher risk of posttransplant death than those with no NSER (hazard ratio 2.43, 95% CI 0.99-5.95, p = 0.05, multivariable analysis), but NSER approval did not impact posttransplant death. Further research on NSER utilization in pediatric liver transplant is needed to optimize organ allocation and outcomes for children.

A 10-Year united network for organ sharing review of mortality and risk factors in young children awaiting liver transplantation

Young children < 2 years of age with chronic end-stage liver disease (YC2) are a uniquely vulnerable group listed for liver transplantation, characterized by a predominance of biliary atresia (BA). To investigate wait-list mortality, associated risk factors, and outcomes of YC2, we evaluated United Network for Organ Sharing registry data from April 2003 to March 2013 for YC2 listed for deceased donor transplant (BA = 994; other chronic liver disease [CLD] = 221). Overall, wait-list mortality among YC2 was 12.4% and posttransplant mortality was 8%, accounting for an overall postlisting mortality of 19.6%. YC2 demonstrated 12.2%, 18.7%, and 20.6% wait-list mortality by 90, 180, and 270 days, respectively. YC2 with CLD demonstrated significantly higher wait-list mortality compared with BA among YC2 (23.9% versus 9.8%; P < 0.05). Multivariate analyses revealed that listing Pediatric End-Stage Liver Disease [PELD] > 21 (hazard ratio [HR], 3.2; 95% confidence interval [CI], 1.6-6.5), lack of exception (HR, 5.8; 95% CI, 2.8-11.8), listing height < 60.6 cm (HR, 2.1; 95% CI, 1.4-3.1), listing weight  > 10 kg (HR, 3.8; 95% CI, 1.5-9.2), and initial creatinine > 0.5 (HR, 6.8; 95% CI, 3.4-13.5) were independent risk factors for YC2 wait-list mortality (P < 0.005 for all). Adjusting for all variables, the risk of death among CLD patients was 2 (95% CI, 1.3-3.1) times greater than patients with BA + surgery (presumed Kasai). Furthermore, the risk of death in BA without surgery was 1.9 (95% CI, 1‐3.4) times greater than BA with presumed Kasai. Our data highlight unacceptably high wait-list and early post-liver transplant mortality in YC2 not predicted by PELD and suggest key risk factors deserving of further study in this age group. Liver Transplantation 22 1584-1592 2016 AASLD.

Urgent listing exceptions and outcomes in pediatric heart transplantation: Comparison to standard criteria patients

BACKGROUND

United Network for Organ Sharing (UNOS) policy enables listing exceptions to avoid penalizing patients with waitlist mortality not captured by standard criteria. Outcomes among patients listed by exception have not been analyzed.

METHODS

We performed a retrospective analysis of pediatric (≤17 years of age, n = 4,706) listings (2006 to 2015) for primary, isolated heart transplantation within the UNOS data set, assessing Status 1A exception (n = 211, 4.5%) use across regions and patient characteristics and evaluating waitlist outcomes compared with candidates listed using standard criteria.

RESULTS

Death or removal for reason other than transplant did not differ between exception and standard criteria patients at 1 month (11.7% vs 16.2%, p = not statistically significant [NS]), 2 months (18.2% vs 29.0%, p = 0.11) or overall (16.1% vs 22.0%, p = NS) on the waitlist. Rates were higher than among Status 1B patients (1 month: 2.8%; 2 months: 5.6%; overall: 14.9%; p < 0.0001). The cumulative incidence of competing risks (transplantation, death/removal for reasons other than transplant and removal) did not differ when comparing Status 1A exception patients with Status 1A standard criteria patients. Use of 1A exceptions varied across UNOS regions (1.9% to 22.3%, p < 0.0001). Risk-adjusted modeling identified patients more (hypertrophic cardiomyopathy: odds ratio [OR] = 2.8, 95% confidence interval [CI] 1.5 to 5.0; restrictive cardiomyopathy: OR = 2.7, 95% CI 1.7 to 4.3) and less (low socioeconomic status: OR = 0.7, 95% CI 0.5 to 1.0) likely to use an exception. Use of exceptions was uncorrelated with regional outcomes.

CONCLUSIONS

Waitlist mortality among Status 1A exception patients is similar to that among those listed by standard criteria. However, variation in exception use across geography and demography may contribute to inequities in access to transplantation, particularly for those with low socioeconomic status. Standardization of practices may decrease regional variation and minimize inequities.