Liver transplant center variability in accepting organ offers and its impact on patient survival

Safety and use of late-turndown liver allografts to increase rate of transplantation

BACKGROUND

The demand for liver transplants (LT) in the United States far surpasses the availability of allografts. New allocation schemes have resulted in occasional difficulties with allograft placement and increased intraoperative turndowns. We aimed to evaluate the outcomes related to use of late-turndown liver allografts.

METHODS

A review of prospectively collected data of LTs at a single center from July 2019 to July 2023 was performed. Late-turndown placement was defined as an open offer 6 h prior to donation, intraoperative turndown by primary center, or post-cross-clamp turndown.

RESULTS

Of 565 LTs, 25.1% (n = 142) received a late-turndown liver allograft. There were no significant differences in recipient age, gender, BMI, or race (all p > 0.05), but MELD was lower for the late-turndown LT recipient group (median 15 vs 21, p < 0.001). No difference in 30-day, 6-month, or 1-year survival was noted on logistic regression, and no difference in patient or graft survival was noted on Cox proportional hazard regression. Late-turndown utilization increased during the study from 17.2% to 25.8%, and median waitlist time decreased from 77 days in 2019 to 18 days in 2023 (p < 0.001).

CONCLUSION

Use of late-turndown livers has increased and can increase transplant rates without compromising post-transplant outcomes with appropriate selection.

Body Size Remains the Major Source of Sex Disparity Despite Updated Liver Transplant Allocation Policies

BACKGROUND

Efforts to address US liver transplant (LT) access inequities continue, yet disparities linked to candidate traits persist.

METHODS

Analyzing national registry data pre- and post-Acuity Circle (AC) policy, our study assessed the impact of low body surface area (BSA) on LT waitlist mortality. The outcomes of LT candidates listed in the pre-AC era (n = 39 227) and post-AC (n = 38 443) were compared for patients with low BSA (22.9% pre-AC and 23.3% post-AC).

RESULTS

Fine-Gray competing risk models highlighted that candidates with low BSA had a lower likelihood of LT both pre-AC (hazard ratio [HR] 0.93; 95% confidence interval [CI], 0.92-0.95) and post-AC (HR 0.96; 95% CI, 0.94-0.98), with minimal improvement in waitlist mortality/dropout risk from pre-AC (HR 1.15; 95% CI, 1.09-1.21) to post-AC (HR 1.13; 95% CI, 1.06-1.19). Findings were mostly reaffirmed by Cox regression models incorporating the trajectory of Model for End-stage Liver Disease (MELD) scores as time-dependent covariates. Regions 3, 5, and 7 showed notable LT waitlist disparities among low BSA patients post-AC policy. Causal mediation analysis revealed that low BSA and the difference between MELD-sodium and MELD 3.0 (MELD_D, as a proxy for the potential impact of the introduction of MELD 3.0) largely explained the sex disparity in AC allocation (percent mediated 90.4).

CONCLUSIONS

LT waitlist disparities for female candidates persist, largely mediated by small body size. Although MELD 3.0 may reduce some disparities, further body size adjustments for in allocation models are justified.

Lost in Transplantation: Characterizing Racial Gaps in Physician Organ Offer Acceptance

Background

There are known racial disparities in the organ transplant allocation system in the United States. However, prior work has yet to establish if transplant center decisions on offer acceptance-the final step in the allocation process-contribute to these disparities.

Objective

To estimate racial differences in the acceptance of organ offers by transplant center physicians on behalf of their patients.

Design

Retrospective cohort analysis using data from the Scientific Registry of Transplant Recipients (SRTR) on patients who received an offer for a heart, liver, or lung transplant between January 1, 2010 and December 31, 2020.

Setting

Nationwide, waitlist-based.

Patients

32,268 heart transplant candidates, 102,823 liver candidates, and 25,780 lung candidates, all aged 18 or older.

Measurements

1) Association between offer acceptance and two race-based variables: candidate race and donor-candidate race match; 2) association between offer rejection and time to patient mortality.

Results

Black race was associated with significantly lower odds of offer acceptance for livers (OR=0.93, CI: 0.88-0.98) and lungs (OR=0.80, CI: 0.73-0.87). Donor-candidate race match was associated with significantly higher odds of offer acceptance for hearts (OR=1.11, CI: 1.06-1.16), livers (OR=1.10, CI: 1.06-1.13), and lungs (OR=1.13, CI: 1.07-1.19). Rejecting an offer was associated with lower survival times for all three organs (heart hazard ratio=1.16, CI: 1.09-1.23; liver HR=1.74, CI: 1.66-1.82; lung HR=1.21, CI: 1.15-1.28).

Limitations

Our study analyzed the observational SRTR dataset, which has known limitations.

Conclusion

Offer acceptance decisions are associated with inequity in the organ allocation system. Our findings demonstrate the additional barriers that Black patients face in accessing organ transplants and demonstrate the need for standardized practice, continuous distribution policies, and better organ procurement.

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

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

Assessing LSAM's ability to account for changes in organ donation and transplant center behavior

The Liver Simulated Allocation Model (LSAM) is used to evaluate proposed organ allocation policies. Although LSAM has been shown to predict the directionality of changes in transplants and nonused organs, the magnitude is often overestimated. One reason is that policymakers and researchers using LSAM assume static levels of organ donation and center behavior because of challenges with predicting future behavior. We sought to assess the ability of LSAM to account for changes in organ donation and organ acceptance behavior using LSAM 2019. We ran 1-year simulations with the default model and then ran simulations changing donor arrival rates (ie, organ donation) and center acceptance behavior. Changing the donor arrival rate was associated with a progressive simulated increase in transplants, with corresponding simulated decreases in waitlist deaths. Changing parameters related to organ acceptance was associated with important changes in transplants, nonused organs, and waitlist deaths in the expected direction in data simulations, although to a much lesser degree than changing the donor arrival rate. Increasing the donor arrival rate was associated with a marked decrease in the travel distance of donor livers in simulations. In conclusion, we demonstrate that LSAM can account for changes in organ donation and organ acceptance in a manner aligned with historical precedent that can inform future policy analyses. As Scientific Registry of Transplant Recipients develops new simulation programs, the importance of considering changes in donation and center practice is critical to accurately estimate the impact of new allocation policies.

Liver machine perfusion technology: Expanding the donor pool to improve access to liver transplantation

The imbalance between organ supply and demand continues to limit the broader benefits of organ transplantation. Machine perfusion (MP) may increase the supply of donor livers by expanding the use of extended-criteria donors. Using the United Network for Organ Sharing/Organ Procurement and Transplantation Network and the Standard Transplant Analysis and Research dataset, we reviewed the effect of MP implementation on the behavior of transplant centers. We identified 15 high-utilizing MP centers that were matched to suitable controls based on volume and geographical proximity. We conducted a differences-in-differences analysis using linear regression to estimate the impact of MP adoption on the transplant centers' donor utilization. We found a significant increase in cold ischemia time and organs with donor warm ischemia time over 30 minutes (P < .05). After removing one outlier center, the analysis showed that these centers through MP accepted overall more donation after circulatory death donors, donation after circulatory death donors over 50 years old, donors with macrovesicular steatosis greater than 30% on liver biopsy, and donor warm ischemia time over 30 minutes (P < .05). MP has allowed centers to expand their use of extended-criteria donors beyond traditional cutoffs and to increase patient access to liver transplantation.

Decreased Utilization Rate of Grafts for Liver Transplantation After Implementation of Acuity Circle-based Allocation

BACKGROUND

The allocation system for livers began using acuity circles (AC) in 2020. In this study, we sought to evaluate the impact of AC policy on the utilization rate for liver transplantation (LT).

METHODS

Using the US national registry data between 2018 and 2022, LTs were equally divided into 2 eras: pre-AC (before February 4, 2020) and post-AC (February 4, 2020, and after). Deceased potential liver donors were defined as deceased donors from whom at least 1 organ was procured.

RESULTS

The annual number of deceased potential liver donors increased post-AC (from 10 423 to 12 259), approaching equal to that of new waitlist registrations for LT (n = 12 801). Although the discard risk index of liver grafts was comparable between the pre- and post-AC eras, liver utilization rates in donation after brain death (DBD) and donation after circulatory death (DCD) donors were lower post-AC ( P  < 0.01; 79.8% versus 83.4% and 23.7% versus 26.0%, respectively). Recipient factors, ie, no recipient located, recipient determined unsuitable, or time constraints, were more likely to be reasons for nonutilization after implementation of the AC allocation system compared to the pre-AC era (20.0% versus 12.3% for DBD donors and 50.1% versus 40.8% for DCD donors). Among non-high-volume centers, centers with lower utilization of marginal DBD donors or DCD donors were more likely to decrease LT volume post-AC.

CONCLUSIONS

Although the number of deceased potential liver donors has increased, overall liver utilization among deceased donors has decreased in the post-AC era. To maximize the donor pool for LT, future efforts should target specific reasons for liver nonutilization.

Donation After Circulatory Death Liver Transplantation: Early Challenges, Clinical Improvement, and Future Directions

Donation after circulatory death (DCD) liver allografts remain a widely underutilized source of donor organs for transplantation. Although initially linked with inferior outcomes, DCD liver transplant can achieve excellent patient and graft survival with suitable matching of donor and recipient characteristics, rapid donor recovery and precise donor assessment, and appropriate perioperative management. The advent of clinical liver perfusion modalities promises to redefine the viability parameters for DCD liver allografts and hopefully will encourage more widespread usage of this growing source of donor livers.

Transplant Candidate Outcomes After Declining a DCD Liver in the United States

BACKGROUND

In the context of the organ shortage, donation after circulatory death (DCD) provides an opportunity to expand the donor pool. Although deceased-donor liver transplantation from DCD donors has expanded, DCD livers continue to be discarded at elevated rates; the use of DCD livers from older donors, or donors with comorbidities, is controversial.

METHODS

Using US registry data from 2009 to 2020, we identified 1564 candidates on whose behalf a DCD liver offer was accepted ("acceptors") and 16 981 candidates on whose behalf the same DCD offers were declined ("decliners"). We characterized outcomes of decliners using a competing risk framework and estimated the survival benefit (adjusted hazard ratio [95% confidence interval]) of accepting DCD livers using Cox regression.

RESULTS

Within 10 y of DCD offer decline, 50.9% of candidates died or were removed from the waitlist before transplantation with any type of allograft. DCD acceptors had lower mortality compared with decliners at 10 y postoffer (35.4% versus 48.9%, P < 0.001). After adjustment for candidate covariates, DCD offer acceptance was associated with a 46% reduction in mortality (0.54 [0.49-0.61]). Acceptors of older (age ≥50), obese (body mass index ≥30), hypertensive, nonlocal, diabetic, and increased risk DCD livers had 44% (0.56 [0.42-0.73]), 40% (0.60 [0.49-0.74]), 48% (0.52 [0.41-0.66]), 46% (0.54 [0.45-0.65]), 32% (0.68 [0.43-1.05]), and 45% (0.55 [0.42-0.72]) lower mortality risk compared with DCD decliners, respectively.

CONCLUSIONS

DCD offer acceptance is associated with considerable long-term survival benefits for liver transplant candidates, even with older DCD donors or donors with comorbidities. Increased recovery and utilization of DCD livers should be encouraged.

The sex disparity in liver transplantation

PURPOSE OF THE REVIEW

This review describes the sex disparity in liver transplantation (LT) and explains its underlying causes.

RECENT FINDINGS

There is a small but persistent sex disparity in transplant rate and waitlist mortality that disappears once women are listed as Status 1. Allocation systems that could replace the Model for End Stage Liver Disease (MELD)-Na with scores less reliant on serum creatine and muscle mass have the potential to alleviate part of the sex disparity. Women perform worse on frailty assessments and are more likely to have nonalcoholic steatohepatitis (NASH). A diagnosis of NASH is compounding risk factor for frailty.

SUMMARY

Women remain disadvantaged in their access to LT despite multiple evolutions of the allocation system. An allocation system that relies less heavily on serum creatinine could partially alleviate the sex disparity. As NASH becomes more prevalent and frailty becomes more important in listing decisions, we may also need to carefully consider differences in the manifestations of frailty between the genders.

The evolution of the liver transplant candidate

The first successful human liver transplant (LT) was done over 60 years ago; since the early pioneering days, this procedure has become a routine treatment with excellent outcomes for the great majority of recipients. Over the last six decades, indications have evolved. Use of LT for hepatic malignancy is becoming less common as factors that define a successful outcome are being increasingly defined, and alternative therapeutic options become available. Both Hepatitis B and C virus associated liver disease are becoming less common indications as medical treatments become more effective in preventing end-stage disease. Currently, the most common indications are alcohol-related liver disease and metabolic associated liver disease. The developing (and controversial) indications include acute on chronic liver failure, alcoholic hepatitis and some rarer malignancies such as non-resectable colorectal cancer liver metastases, neuroendocrine tumours and cholangiocarcinoma. Candidates are becoming older and with greater comorbidities, A relative shortage of donor organs remains the greatest cause for reducing access to LT; therefore, various countries have developed transparent approaches to allocation of this life saving and life enhancing resource. Reliance on prognostic models has gone some way to improve transparency and increase equity of access but these approaches have their limitations.

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.

The use of nondirected donor organs in living donor liver transplantation: Perspectives and guidance

Interest in anonymous nondirected living organ donation is increasing in the United States and a small number of transplantation centers are accumulating an experience regarding nondirected donation in living donor liver transplantation. Herein, we review current transplant policy, discuss emerging data, draw parallels from nondirected kidney donation, and examine relevant considerations in nondirected living liver donation. We aim to provide a consensus guidance to ensure safe evaluation and selection of nondirected living liver donors and a schema for just allocation of nondirected grafts.

Center variations in patient selection for simultaneous heart-kidney transplantation

There are no established regulations governing patient selection for simultaneous heart-kidney (SHK) transplantation, creating the potential for significant center-level variations in clinical practice.

METHODS

Using the United Network for Organ Sharing (UNOS) Standard Transplant Analysis and Research (STAR) file, we examined practice trends and variations in patient selection for SHK at the center level between January 1, 2004 and March 31, 2019.

RESULTS

Overall, SHK is becoming more common with most centers performing heart transplants also performing SHK. Among patients who underwent heart transplant who were receiving dialysis, the rate of SHK varied from 22% to 86% at the center level. Among patients not on dialysis, the median estimated glomerular filtration rate (eGFR) of patients receiving SHK varied between 19 and 59 mL/min/1.73 m² . When adjusting for other factors, the odds of SHK varied 57-fold between the highest and lowest SHK performing centers.

CONCLUSION

Variation in SHK at the center level suggests the need for national guidelines around the selection of patients for SHK.

Risk Aversion, Organ Utilization and Changing Behavior

Improving organ acceptance and utilization rates is critical to ensure we maximize usage of donated organs as a scarce resource. Many factors underlie unnecessary discard of viable organs. Declined transplantation opportunities for candidates is associated with increased wait-list mortality. Technological advancements in organ preservation may help bridge the gap between donation and utilization, but an overlooked obstacle is the practice of risk aversion by transplant professionals when decision-making under risk. Lessons from behavioral economics, where experimental work has outlined the impact of loss or risk aversion on decision-making, have not been translated to transplantation. Many external factors can influence decision-making when accepting or utilizing organs, which are potentially amendable if external conditions are improved. However, attitudes and perceptions to risk for transplant professionals can pervade decision-making and influence behaviour. If we wish to change this behavior, then the underlying nature of decision-making under risk when accepting or utilizing organs must be studied to facilitate the design of targeted behavior change interventions to convert risk aversion to risk tolerance. To ensure optimal use of donated organs, we need more research into decision-making under risk.

Offer Acceptance Patterns for Liver Donors Aged 70 and Older

Despite a documented survival benefit, older liver donor (OLD, age ≥70) graft offers are frequently declined, with utilization worsening over the last decade. To understand how offer acceptance varies by center, we studied 1113 eventually transplanted OLD grafts from 2009 to 2017 using Scientific Registry of Transplant Recipients (SRTR) data and random-intercept multilevel logistic regression. To understand how center-level acceptance of OLD graft offers might be associated with waitlist and posttransplant outcomes, we studied all adult, actively listed, liver-only candidates and recipients during the study period using Poisson regression (transplant rate), competing risks regression (waitlist mortality), and Cox regression (posttransplant mortality). Among 117 centers, OLD offer acceptance ranged from 0 (23 centers) to 95 acceptances, with a median odds ratio of 2.88. Thus, a candidate may be three times as likely to receive an OLD graft simply by listing at a different center. Centers in the highest quartile (Q4) of OLD acceptance (accepted 39% of OLD offers) accepted more nationally shared organs (Q4 versus Q1: 14.1% versus 0.0%, P < 0.001) and had higher annual liver transplant volume (Q4 versus Q1: 80 versus 21, P < 0.001). After adjustment, nationally shared OLD offers (adjusted odds ratio [aOR]: 0.16, 95% confidence interval [CI]: 0.13-0.20) and offers to centers with higher median Model for End-Stage Liver Disease (MELD) at transplant (aOR: 0.74, 95% CI: 0.62-0.87) were less likely to be accepted. OLD offers to centers with higher annual transplant volume were more likely to be accepted (aOR: 1.21, 95% CI: 1.14-1.30). Additionally, candidates listed at centers within the highest quartile of OLD graft offer acceptance had higher deceased donor liver transplantation (DDLT) rates (adjusted incidence rate ratio: 1.45, 95% CI: 1.41-1.50), lower waitlist mortality (adjusted subhazard ratio: 0.76, 95% CI: 0.72-0.76), and similar posttransplant survival (adjusted hazard ratio: 0.93, 95% CI: 0.86-1.01) when compared with those listed at centers in the lowest quartile of OLD graft offer acceptance. The wide variation in OLD offer acceptance supports the need for optimizing the organ offer process and efficiently directing OLD offers to centers more likely to use them.

The Suitability of Potential Organ Donors Using Real Case-Scenarios; Do we Need to Create a "Donor Board" Process for Donors Perceived as Unlikely Suitable?

Introduction: Despite availability of selection criteria, different interpretations can lead to variability in the appreciation of donor eligibility with possible viable organs missed. Our primary objective was to test the perception of feasibility of potential organ donors through the survey of a small sample of external evaluators.

Methods: Clinical scenarios summarizing 66 potential donors managed in the first year of our Organ Recovery Center were sent to four critical care physicians to evaluate the feasibility of the potential donors and the probability of organ procurement.

Results: Potential donors procuring at least one organ were identified in 55 of the 66 cases (83%). Unanimity was reached in 38 cases, encompassing 35 out of the 55 converted and 3 of the non-converted donors. The overall agreement was moderate (kappa = 0.60, 95% CI: 0.37–0.82). For the organs finally procured for transplantation, organ donation was predicted for the majority of the cases, but high discrepancy was present with the final outcome of organs not procured (particularly liver and kidney).

Conclusion: The assessment of a potential donor is a complex dynamic process. In order to increase organ availability, standardized electronically clinical data, as well a “donor board” structure of decision might inform future systems.

Center variation in long-term outcomes for socioeconomically deprived children

Neighborhood socioeconomic deprivation is associated with adverse outcomes after pediatric liver transplant. We sought to determine if this relationship varies by transplant center. Using SRTR, we included patients <18 years transplanted 2008-2013 (N = 2804). We matched patient ZIP codes to a deprivation index (range [0,1]; higher values indicate increased socioeconomic deprivation). A center-level patient-mix deprivation index was defined by the distribution of patient-level deprivation. Centers (n = 66) were classified as high or low deprivation if their patient-mix deprivation index was above or below the median across centers. Center quality was classified as low or high graft failure if graft survival rates were better or worse than the overall 10-year graft survival rate. Primary outcome was patient-level graft survival. We used random-effect Cox models to evaluate center-level covariates on graft failure. We modeled center quality using stratified Cox models. In multivariate analysis, each 0.1 increase in the patient-mix deprivation index was associated with increased hazard of graft failure (HR 1.32; 95%CI: 1.05, 1.66). When stratified by center quality, patient-mix deprivation was no longer significant (HR 1.07, 95%CI: 0.89, 1.28). Some transplant centers care for predominantly high deprivation children and maintain excellent outcomes. Revealing and replicating these centers' practice patterns should enable more equitable outcomes.

Recommendations for Donor and Recipient Selection and Risk Prediction: Working Group Report From the ILTS Consensus Conference in DCD Liver Transplantation

Although the utilization of donation after circulatory death donors (DCDs) for liver transplantation (LT) has increased steadily, much controversy remains, and no common acceptance criteria exist with regard to donor and recipient risk factors and prediction models. A consensus conference was organized by International Liver Transplantation Society on January 31, 2020, in Venice, Italy, to review the current clinical practice worldwide regarding DCD-LT and to develop internationally accepted guidelines. The format of the conference was based on the grade system. International experts in this field were allocated to 6 working groups and prepared evidence-based recommendations to answer-specific questions considering the currently available literature. Working group members and conference attendees served as jury to edit and confirm the final recommendations presented at the end of the conference by each working group separately. This report presents the final statements and recommendations provided by working group 2, covering the entire spectrum of donor and recipient risk factors and prediction models in DCD-LT.

Reexamining Risk Aversion: Willingness to Pursue and Utilize Nonideal Donor Livers Among US Donation Service Areas

Background

Livers from "nonideal" but acceptable donors are underutilized; however, organ procurement organization (OPO) metrics do not assess how OPO-specific practices contribute to these trends. In this analysis, we evaluated nonideal liver donor avoidance or risk aversion among OPOs and within US donation service areas (DSAs).

Methods

Adult donors in the United Network for Organ Sharing registry who donated ≥1 organ for transplantation between 2007 and 2019 were included. Nonideal donors were defined by any of the following: age > 70, hepatitis C seropositive, body mass index > 40, donation after circulatory death, or history of malignancy. OPO-specific performance was evaluated based on rates of nonideal donor pursuit and consent attainment. DSA performance (OPO + transplant centers) was evaluated based on rates of nonideal donor pursuit, consent attainment, liver recovery, and transplantation. Lower rates were considered to represent increased donor avoidance or increased risk aversion.

Results

Of 97 911 donors, 31 799 (32.5%) were nonideal. Unadjusted OPO-level rates of nonideal donor pursuit ranged from 88% to 100%. In a 5-tier system of overall risk aversion, tier 5 DSAs (least risk-averse) and tier 1 DSAs (most risk-averse) had the highest and lowest respective rates of non-ideal donor pursuit, consent attainment, liver recovery, and transplantation. On average, recovery rates were over 25% higher among tier 5 versus tier 1 DSAs. If tier 1 DSAs had achieved the same average liver recovery rate as tier 5 DSAs, approximately 2100 additional livers could have been recovered during the study period.

Conclusion

Most OPOs aggressively pursue nonideal liver donors; however, recovery practices vary widely among DSAs. Fair OPO evaluations should consider early donation process stages to best disentangle OPO and center-level practices.

Race, Education, and Gender Disparities in Transplantation of Kidneys From Hepatitis C Viremic Donors

BACKGROUND

Transplantation of kidneys from hepatitis C virus (HCV)-viremic donors into HCV-negative patients followed by direct-acting antiviral therapy was an important breakthrough to increase the number of life-saving kidney transplants. Data suggest that these transplants offer several benefits; however, it is unknown whether adoption of this practice has been shared equitably, especially among disadvantaged groups.

METHODS

We evaluated United Network for Organ Sharing data on HCV-seronegative adult deceased-donor kidney transplant recipients from January 1, 2017, to June 12, 2020. We compared recipients of a kidney from an HCV antibody- (Ab-)/nucleic acid test- (NAT-), HCV Ab+/NAT-, and HCV NAT+ donor. The primary covariates were as follows: (1) race/ethnicity; (2) female sex; and (3) highest level of education. Models included variables associated with being offered an HCV NAT+ kidney. We fit mixed-effects multinomial logistic regression models with the center as a random effect to account for patient clustering.

RESULTS

Of 48 255 adult kidney-alone deceased-donor kidney transplant HCV-seronegative recipients, 1641 (3.4%) donors were HCV NAT+-, increasing from 0.3% (January 2017-June 2017) to 6.9% (January 2020-June 2020). In multivariable models, racial/ethnic minorities, women, and those with less education were significantly less likely to receive a kidney from an HCV NAT+ donor relative to an HCV Ab-/NAT- and HCV Ab+/NAT- donor. The disparities were most pronounced among Hispanic and Asian patients with less educational attainment (grade school, high school, or some college/tech school).

CONCLUSIONS

Despite an increase in transplants from HCV NAT+ donors, we found substantial racial/ethnic disparities in transplantation of these kidneys. These data highlight how the benefits of a scientific breakthrough are often made less available to disadvantaged patients.

A machine learning approach for the prediction of overall deceased donor organ yield

BACKGROUND

Optimizing organ yield (number of organs transplanted per donor) is a potentially modifiable way to increase the number of organs available for transplant. Models to predict the expected deceased donor organ yield have been developed based on ordinary least squares regression and logistic regression. However, alternative modeling methodologies incorporating machine learning may have superior performance compared with conventional approaches.

METHODS

We evaluated the predictive accuracy of 14 machine learning models for predicting overall organ yield in a cross-validation procedure. The models were parameterized using data from the Organ Procurement and Transplantation Network database from 2000 to 2018. The inclusion criteria for the study were adult deceased donors between 18 and 84 years of age that had at least 1 organ procured for transplantation.

RESULTS

A total of 89,520 donors met the inclusion criteria. Their mean (standard deviation) age was 44 (15) years, and approximately 58% were male. Our cross-validation analysis showed that a tree-based gradient boosting model outperformed the remaining 13 models. Compared with the currently used prediction models, the gradient boosting model improves prediction accuracy by reducing the mean absolute error between 3 and 11 organs per 100 donors.

CONCLUSION

Our analysis demonstrated that the gradient boosting methodology had the best performance in predicting overall deceased donor organ yield and can potentially serve as an aid to assess organ procurement organization performance.

Viability Assessment in Liver Transplantation-What Is the Impact of Dynamic Organ Preservation?

Based on the continuous increase of donor risk, with a majority of organs classified as marginal, quality assessment and prediction of liver function is of utmost importance. This is also caused by the notoriously lack of effective replacement of a failing liver by a device or intensive care treatment. While various parameters of liver function and injury are well-known from clinical practice, the majority of specific tests require prolonged diagnostic time and are more difficult to assess ex situ. In addition, viability assessment of procured organs needs time, because the development of the full picture of cellular injury and the initiation of repair processes depends on metabolic active tissue and reoxygenation with full blood over several hours or days. Measuring injury during cold storage preservation is therefore unlikely to predict the viability after transplantation. In contrast, dynamic organ preservation strategies offer a great opportunity to assess organs before implantation through analysis of recirculating perfusates, bile and perfused liver tissue. Accordingly, several parameters targeting hepatocyte or cholangiocyte function or metabolism have been recently suggested as potential viability tests before organ transplantation. We summarize here a current status of respective machine perfusion tests, and report their clinical relevance.

Transplant Center Variability in Organ Offer Acceptance and Mortality Among US Patients on the Heart Transplant Waitlist

Importance

Under the current Centers for Medicare & Medicaid Services guidelines, there is incentivization to optimize posttransplant outcomes regardless of mortality among patients on the waitlist and transplant rates; few data exist with regard to transplant center acceptance practices and survival to heart transplant.

Objectives

To evaluate the extent of variability in organ acceptance practices in the US and whether this center-level behavior is associated with heart transplant candidate survival.

Design, Setting, and Participants

In this retrospective cohort study, the US National Transplant Registry was queried for all match runs of adult candidates listed for isolated heart transplant between May 1, 2007, and March 31, 2017. Data analysis was conducted from October 30, 2018, to May 1, 2019. The final cohort included 93 transplant centers, 19 703 donors, and 9628 candidates.

Main Outcomes and Measures

Center acceptance rates for heart allografts offered to the highest-priority candidates, association between center acceptance rate and mortality among patients on the waitlist, and posttransplant outcomes between candidates who accepted their first-rank offers vs those who accepted previously declined offers.

Results

Among 19 703 unique organ offers, 6302 hearts (32.0%) were accepted for first-rank candidates. After adjustment for donor, candidate, and geographic covariates, transplant centers varied in acceptance rates (12.3%-61.5%) of offers made to first-rank candidates. Higher acceptance rates were associated with lower cumulative incidence of 1-year mortality among patients on the waitlist. For every 10% increase in adjusted center acceptance rate, the risk of mortality decreased by 27% (subdistribution hazard ratio, 0.73; 95% CI, 0.67-0.80). No statistically significant difference was observed in 5-year adjusted posttransplant patient survival (adjusted hazard ratio, 1.02; 95% CI, 0.94-1.11) and graft failure (subdistribution hazard ratio; 0.95; 95% CI, 0.83-1.09) between hearts accepted at the first-rank compared with lower-rank positions.

Conclusions and Relevance

Variability in heart allograft acceptance rates appears to exist among transplant centers, with candidates listed at lower acceptance rate centers being more likely to experience mortality while on the waitlist. Comparable posttransplant survival suggests that allografts that were declined as a first offer perform as well as those that were accepted at their first offer. These findings suggest that organ acceptance rate or time to transplant from being added to the waitlist may be an additional measure of heart transplant program performance.

Center Variation in Intention-to-Treat Survival Among Patients Listed for Liver Transplant

In the United States, centers performing liver transplant (LT) are primarily evaluated by patient survival within 1 year after LT, but tight clustering of outcomes allows only a narrow window for evaluation of center variation for quality improvement. Alternate measures more relevant to patients and the transplant community are needed. We examined adults listed for LT in the United States, using data submitted to the Scientific Registry of Transplant Recipients. Intention-to-treat (ITT) survival was defined as survival within 1 year from listing, regardless of transplant. Mixed effects/frailty models were used to assess center variation in ITT survival. Between January 2010 and December 2016, there were 66,428 new listings at 113 centers. Overall, median 1-year ITT survival was 79.8% (interquartile range [IQR], 76.1%-83.4%), whereas 1-year waiting-list (WL) survival was 75.8% (IQR, 71.2%-79.4%), and 1-year post-LT survival was 90.0% (IQR, 87.9%-91.8%). Higher rates of ITT mortality were correlated with increased WL mortality (correlation, r = 0.76), increased post-LT mortality (r = 0.31), lower volume centers (r = -0.34), and lower transplant rate ratio (r = -0.25). Similar patterns were observed in the subgroup of WL candidates listed with Model for End-Stage Liver Disease (MELD) ≥25: median 1-year ITT survival was 65.2% (IQR, 60.2%-72.6%), whereas 1-year post-LT survival was 87.5% (IQR, 84.0%-90.9%), and 1-year WL survival was 36.6% (IQR, 27.9%-47.0%). In mixed effects modeling, the transplant center was an independent predictor of ITT survival even after adjustment for age, sex, MELD, and sociodemographic variables. Center variation for ITT survival was larger compared with post-LT survival. The measurement of ITT outcome offers a complementary method to assess center performance. This is a first step toward understanding differences in program quality beyond patient and graft survival after LT.

RELATIONSHIP BETWEEN DONOR QUALITY AND RECIPIENT GRAVITY IN LIVER TRANSPLANT

Background:

Tools such as MELD score and DRI are currently used to predict risks and benefits on liver allocation for transplantation.

Aim:

To evaluate the relation between donor quality and recipient severity on liver allocation.

Methods:

Liver transplants performed in 2017 and 2018 were evaluated. Data were collected from Paraná’s State Government Registry. DRI was evaluated in relation to recipient MELD score and position on waiting list.

Results:

It was observed relation between DRI and position on waiting list: higher risk organs were allocated to recipients with worse waiting list position. There was no relation between DRI and MELD score. Afrodescendents and elderly donor organs were allocated to lower MELD score and worse waiting list position recipients.

Conclusion:

There is no relation between DRI and MELD on liver allocation. However, DRI interferes with allocation decision based on recipients waiting list position. Donor race and age interfere on both recipient MELD score and waiting list position

Growth through adversity: posttraumatic growth in anonymous living liver donors

PURPOSE

Post-traumatic growth (PTG) is positive change that occurs after struggling with challenging life crises. Research on PTG has typically been limited to oncology populations, first-responders, and individuals in warzones. We report the experience of PTG amongst a sample of 26 anonymous live liver donors.

METHODS

Anonymous donors were those with no biological connection or prior relationship with recipients. Twenty-six participants participated in a semi-structured qualitative interview examining their experience with, and outcomes of donation. Interview transcripts were analyzed for themes about PTG using the constant comparison method.

RESULTS

While some donors indicated that donation had little lasting impact on their life, most cited significant personal and interpersonal changes resulting from the experience. The most common positive changes included deepened bonds with others, appreciation for personal strength, clearer life direction, legacy-building, and a connection to the transplant community.

CONCLUSION

Despite the short-term physical trauma of living donor surgery, the act of anonymous donation appeared to be a catalyst for positive long-term psychological growth. These findings help to bolster the ethical argument in favour of anonymous donation.IMPLICATIONS FOR REHABILITATIONThere is a shortage of organ donors for recipients in need, and anonymous living liver donors can successfully reduce wait times and mortality rates for those on wait lists.There are some questions about the ethics of anonymous donation due to possible negative physical and psychological effects of donation surgery on donors.In a qualitative study, this study shows that donors ascribe significant meaning to, and derive many psychological benefits from, their donation experience.These findings provide insights about how to best support anonymous donors through and after their donation experience.

Quantifying Sex-Based Disparities in Liver Allocation

Importance

Differences in local organ supply and demand have introduced geographic inequities in the Model for End-stage Liver Disease (MELD) score-based liver allocation system, prompting national debate and patient-initiated lawsuits. No study to our knowledge has quantified the sex disparities in allocation associated with clinical vs geographic characteristics.

Objective

To estimate the proportion of sex disparity in wait list mortality and deceased donor liver transplant (DDLT) associated with clinical and geographic characteristics.

Design, Setting, and Participants

This retrospective cohort study used adult (age ≥18 years) liver-only transplant listings reported to the Organ Procurement and Transplantation Network from June 18, 2013, through March 1, 2018.

Exposure

Liver transplant waiting list.

Main Outcomes and Measures

Primary outcomes included wait list mortality and DDLT. Multivariate Cox proportional hazards regression models were constructed, and inverse odds ratio weighting was used to estimate the proportion of disparity across geographic location, MELD score, and candidate anthropometric and liver measurements.

Results

Among 81 357 adults wait-listed for liver transplant only, 36.1% were women (mean [SD] age, 54.7 [11.3] years; interquartile range, 49.0-63.0 years) and 63.9% were men (mean [SD] age, 55.7 [10.1] years; interquartile range, 51.0-63.0 years). Compared with men, women were 8.6% more likely to die while on the waiting list (adjusted hazard ratio [aHR], 1.11; 95% CI, 1.04-1.18) and were 14.4% less likely to receive a DDLT (aHR, 0.86; 95% CI, 0.84-0.88). In the geographic domain, organ procurement organization was the only variable that was significantly associated with increased disparity between female sex and wait list mortality (22.1% increase; aHR, 1.22; 95% CI, 1.09-1.30); no measure of the geographic domain was associated with DDLT. Laboratory and allocation MELD scores were associated with increases in disparities in wait list mortality: 1.14 (95% CI, 1.09-1.19; 50.1% increase among women) and DDLT: 0.87 (95% CI, 0.86-0.88; 10.3% increase among women). Candidate anthropometric and liver measurements had the strongest association with disparities between men and women in wait list mortality (125.8% increase among women) and DDLT (49.0% increase among women).

Conclusions and Relevance

Our findings suggest that addressing geographic disparities alone may not mitigate sex-based disparities, which were associated with the inability of the MELD score to accurately estimate disease severity in women and to account for candidate anthropometric and liver measurements in this study.

Tool to Aid Patients in Selecting a Liver Transplant Center

Variations in candidate and donor acceptance criteria may influence access and mortality for liver transplantation. We sought to understand how recipient and donor characteristics vary across centers and how patients interpret this information, and we used these data to develop a tool to provide tailored information to candidates seeking a center (www.transplantcentersearch.org). We analyzed liver recipient data from the Scientific Registry of Transplant Recipients to determine how recipient and donor characteristics (eg, age, Medicaid use, and human immunodeficiency virus status) varied across programs. Data included recipients and donors at each US program between January 1, 2015, and December 31, 2017. The variation in characteristics was plotted with centers stratified by total transplant volume and by volume of each characteristic. A subset of characteristics was plotted to show variation over 3 years. We created mockups of potential reports displaying recipient characteristics alongside pretransplant and posttransplant outcomes and solicited feedback at patient and family interviews and focus groups, which included 39 individuals: 10 pilot interviews with candidates seeking liver transplant at the University of Minnesota-Fairview (UMNF) and 5 focus groups with 13 UMNF candidates, 6 UMNF family members, and 10 national recipients. Transcripts were analyzed using a thematic analysis. Several themes emerged: (1) Candidates experience gaps in existing education about center options; (2) patients requested information about how selection criteria might impact access to transplant; and (3) information tailored to a candidate's medical characteristics can inform decisions. Characteristics shown on mockups varied across centers (P < 0.01). Variation was widespread for small and large centers. In conclusion, variation exists in recipient and donor characteristics across centers. Liver transplant patients provide positive feedback upon viewing patient-specific search tools.

Variability in donor organ offer acceptance and lung transplantation survival

BACKGROUND

Lung transplantation offers a survival benefit for patients with end-stage lung disease. When suitable donors are identified, centers must accept or decline the offer for a matched candidate on their waitlist. The degree to which variability in per-center offer acceptance practices impacts candidate survival is not established. The purpose of this study was to determine the degree of variability in per-center rates of lung transplantation offer acceptance and to ascertain the associated contribution to observed differences in per-center waitlist mortality.

METHODS

We performed a retrospective cohort study of candidates waitlisted for lung transplantation in the US using registry data. Logistic regression was fit to assess the relationship of offer acceptance with donor, candidate, and geographic factors. Listing center was evaluated as a fixed effect to determine the adjusted per-center acceptance rate. Competing risks analysis employing the Fine-Gray model was undertaken to establish the relationship between adjusted per-center acceptance and waitlist mortality.

RESULTS

Of 15,847 unique organ offers, 4,735 (29.9%) were accepted for first-ranked candidates. After adjustment for important covariates, transplant centers varied markedly in acceptance rate (9%-67%). Higher cumulative incidence of 1-year waitlist mortality was associated with lower acceptance rate. For every 10% increase in adjusted center acceptance rate, the risk of waitlist mortality decreased by 36.3% (sub-distribution hazard ratio 0.637; 95% confidence interval 0.592-0.685).

CONCLUSIONS

Variability in center-level behavior represents a modifiable risk factor for waitlist mortality in lung transplantation. Further intervention is needed to standardize center-level offer acceptance practices and minimize waitlist mortality.

Donor outcomes in anonymous live liver donation

BACKGROUND & AIMS

Death rates on liver transplant waiting lists range from 5%-25%. Herein, we report a unique experience with 50 anonymous individuals who volunteered to address this gap by offering to donate part of their liver to a recipient with whom they had no biological connection or prior relationship, so called anonymous live liver donation (A-LLD).

METHODS

Candidates were screened to confirm excellent physical, mental, social, and financial health. Demographics and surgical outcomes were analyzed. Qualitative interviews after donation examined motivation and experiences. Validated self-reported questionnaires assessed personality traits and psychological impact.

RESULTS

A total of 50 A-LLD liver transplants were performed between 2005 and 2017. Most donors had a university education, a middle-class income, and a history of prior altruism. Half were women. Median age was 38.5 years (range 20-59). Thirty-three (70%) learned about this opportunity through public or social media. Saving a life, helping others, generativity, and reciprocity for past generosity were motivators. Social, financial, healthcare, and legal support in Canada were identified as facilitators. A-LLD identified most with the personality traits of agreeableness and conscientiousness. The median hospital stay was 6 days. One donor experienced a Dindo-Clavien Grade 3 complication that completely resolved. One-year recipient survival was 91% in 22 adults and 97% in 28 children. No A-LLD reported regretting their decision.

CONCLUSIONS

This is the first and only report of the characteristics, motivations and facilitators of A-LLD in a large cohort. With rigorous protocols, outcomes are excellent. A-LLD has significant potential to reduce the gap between transplant organ demand and availability.

LAY SUMMARY

We report a unique experience with 50 living donors who volunteered to donate to a recipient with whom they had no biological connection or prior relationship (anonymous living donors). This report is the first to discuss motivations, strategies and facilitators that may mitigate physical, social and ethical risk factors in this patient population. With rigorous protocols, anonymous liver donation and recipient outcomes are excellent; with appropriate clinical expertise and system facilitators in place, our experience suggests that other centers may consider the procedure for its significant potential to reduce the gap between transplant organ demand and availability.

Geographic Disparity in Deceased Donor Liver Transplant Rates Following Share 35

BACKGROUND

The Organ Procurement and Transplantation Network implemented Share 35 on June 18, 2013, to broaden deceased donor liver sharing within regional boundaries. We investigated whether increased sharing under Share 35 impacted geographic disparity in deceased donor liver transplantation (DDLT) across donation service areas (DSAs).

METHODS

Using Scientific Registry of Transplant Recipients June 2009 to June 2017, we identified 86 083 adult liver transplant candidates and retrospectively estimated Model for End-Stage Liver Disease (MELD)-adjusted DDLT rates using nested multilevel Poisson regression with random intercepts for DSA and transplant program. From the variance in DDLT rates across 49 DSAs and 102 programs, we derived the DSA-level median incidence rate ratio (MIRR) of DDLT rates. MIRR is a robust metric of heterogeneity across each hierarchical level; larger MIRR indicates greater disparity.

RESULTS

MIRR was 2.18 pre-Share 35 and 2.16 post-Share 35. Thus, 2 candidates with the same MELD in 2 different DSAs were expected to have a 2.2-fold difference in DDLT rate driven by geography alone. After accounting for program-level heterogeneity, MIRR was attenuated to 2.10 pre-Share 35 and 1.96 post-Share 35. For candidates with MELD 15-34, MIRR decreased from 2.51 pre- to 2.27 post-Share 35, and for candidates with MELD 35-40, MIRR increased from 1.46 pre- to 1.51 post-Share 35, independent of program-level heterogeneity in DDLT. DSA-level heterogeneity in DDLT rates was greater than program-level heterogeneity pre- and post-Share 35.

CONCLUSIONS

Geographic disparity substantially impacted DDLT rates before and after Share 35, independent of program-level heterogeneity and particularly for candidates with MELD 35-40. Despite broader sharing, geography remains a major determinant of access to DDLT.

Geographic disparities in liver supply/demand ratio within fixed-distance and fixed-population circles

Recent OPTN proposals to address geographic disparity in liver allocation have involved circular boundaries: the policy selected 12/17 allocated to 150-mile circles in addition to DSAs/regions, and the policy selected 12/18 allocated to 150-mile circles eliminating DSA/region boundaries. However, methods to reduce geographic disparity remain controversial, within the OPTN and the transplant community. To inform ongoing discussions, we studied center-level supply/demand ratios using SRTR data (07/2013-06/2017) for 27 334 transplanted deceased donor livers and 44 652 incident waitlist candidates. Supply was the number of donors from an allocation unit (DSA or circle), allocated proportionally (by waitlist size) to the centers drawing on these donors. We measured geographic disparity as variance in log-transformed supply/demand ratio, comparing allocation based on DSAs, fixed-distance circles (150- or 400-mile radius), and fixed-population (12- or 50-million) circles. The recently proposed 150-mile radius circles (variance = 0.11, P = .9) or 12-million-population circles (variance = 0.08, P = .1) did not reduce the geographic disparity compared to DSA-based allocation (variance = 0.11). However, geographic disparity decreased substantially to 0.02 in both larger fixed-distance (400-mile, P < .001) and larger fixed-population (50-million, P < .001) circles (P = .9 comparing fixed distance and fixed population). For allocation circles to reduce geographic disparities, they must be larger than a 150-mile radius; additionally, fixed-population circles are not superior to fixed-distance circles.

Quantifying the Effect of Transplanting Older Donor Livers Into Younger Recipients: The Need for Donor-recipient Age Matching

BACKGROUND

Increasing recipient and donor age are independently associated with survival after liver transplantation (LT). Whether donor age differentially impacts post-LT outcomes based on recipient age is unknown.

METHODS

This was a retrospective cohort study using Organ Procurement and Transplantation Network data. All adult deceased-donor, single organ, primary LTs from 2002 to 2015 were included. Donor and recipient age were categorized as younger than 40 years, 40 to 59 years, and 60 years or older. Mixed-effects survival analysis evaluated the risk of graft failure and death according to the interaction of donor and recipient age categories.

RESULTS

Of 63 628 LTs, 6.6% were in recipients younger than 40 years, of which 51.4% used an age-matched donor younger than 40 years. There was a significant among-center variability unrelated to United Network for Organ Sharing region in the use of older organs in young recipients, ranging from 0% to 25% or greater (overall center median, 9.7%; interquartile range, 5.4-16.5%). There was a significant interaction between donor and recipient age (P < 0.05) such that the impact of older donor age was more pronounced in younger recipients. Transplanting livers from donors aged 40 to 59 years and 60 years or older was associated with worse graft survival in recipients younger than 40 years, but there was no difference based on donor age in recipients 60 years or older.

CONCLUSIONS

There is a differential impact of using older donors in younger recipients than that in older recipients. Given their longer expected post-LT survival and the ethical imperative to maximize utilization of the scarce resource of transplantable livers, efforts should be made to allocate the highest-quality organs to those most likely to derive lasting benefit.

Donor Lung Sequence Number and Survival after Lung Transplantation in the United States

RATIONALE

In the United States, an algorithm known as the "match-run" creates an ordered ranking of potential recipients for available lung allografts. A potential recipient's match-run position, or "sequence number," is available to the transplant center when contacted with a lung offer. Lung offers with higher sequence numbers may be interpreted as a crowd-sourced evaluation of poor organ quality, though the association between the sequence number at which a lung is accepted and its recipient's post-transplant outcomes is unclear.

OBJECTIVES

We sought to evaluate the primary reasons provided when a lung offer was refused by a transplant center, transplant center and donor/organ factors associated with a higher sequence number at acceptance, and the association of the sequence number at acceptance with post-transplant mortality and graft failure.

METHODS

Match-run outcomes for lung offers that occurred in the United States from May 2007 through June 2014 were merged with recipient follow-up data through December 2017. Associations between the sequence number at the time of acceptance and selected transplant center and donor characteristics were estimated using multivariable logistic and multinomial regression models. The associations between the final sequence number and recipient survival and graft survival were estimated using multivariable time-to-event models.

RESULTS

Of 10,981 lung offer acceptances, nearly 70% were accepted by one of the top 10 ranked candidates. Higher median annual center volume and potential indicators of organ quality (e.g., abnormal chest radiograph or bronchoscopy) were associated with a higher sequence number at acceptance. There was weak evidence for a small positive relationship between the sequence number at acceptance and both mortality and graft failure. For example, the unadjusted and adjusted hazard ratios for death associated with the log-sequence number at acceptance were 1.019 (95% confidence interval, 1.001-1.038) and 1.011 (95% confidence interval, 0.989-1.033), respectively. On the absolute scale, using the multivariable model, a 10-fold increase in the sequence number translated into a 0.8% absolute decline in the predicted 5-year survival.

CONCLUSIONS

Acceptance of a donor lung offer at a later point in the match-run was associated with measurable indicators of organ quality, but not with clinically meaningful differences in post-transplant mortality or graft failure.

The effect of Share 35 on biliary complications: An interrupted time series analysis

The purpose of the Share 35 allocation policy was to improve liver transplant waitlist mortality, targeting high MELD waitlisted patients. However, policy changes may also have unintended consequences that must be balanced with the primary desired outcome. We performed an interrupted time series assessing the impact of Share 35 on biliary complications in a select national liver transplant population using the Vizient CDB/RM database. Liver transplants that occurred between October 2012 and September 2015 were included. There was a significant change in the incident-rate of biliary complications between Pre-Share 35 (n = 3018) and Post-Share 35 (n = 9984) cohorts over time (P = .023, r²  = .44). As a control, a subanalysis was performed throughout the same time period in Region 9 transplant centers, where a broad sharing agreement had previously been implemented. In the subanalysis, there was no change in the incident-rate of biliary complications between the two time periods. Length of stay and mean direct cost demonstrated a change after implementation of Share 35, although they did not meet statistical difference. While the target of improved waitlist mortality is of utmost importance for the equitable allocation of organs, unintended consequences of policy changes should be studied for a full assessment of a policy's impact.

The Transplant Index: A Novel Method to Predict Adult Liver Transplant Waitlist Outcomes

BACKGROUND

The field of transplantation is shifting outcome priorities from 1-year survival to more comprehensive metrics including transplant rate and waitlist mortality. Identifying disenfranchised candidates (high waitlist death risk, low transplantation chance) can be a focus to improve outcomes.

METHODS

Given the waitlist outcomes (continued waiting, death, and transplantation), we aimed to identify factors predicting the likelihood candidates would undergo transplant or death by performing multivariate competing risk analyses of 121 198 candidates in the United Network for Organ Sharing database. We incorporated these probabilities (likelihood of transplantation and waitlist death) into the Transplant Index (TI) to identify disenfranchised candidates (high likelihood of death, low likelihood of transplantation).

RESULTS

Half of the patients had low incidences of death and transplantation within 90 days (TI-inactive). The remaining were stratified into 10 groups within a predictive index, the TI. Low TI groups (TI 10, 20, 30) had 90-day transplant rates of 50.8%, 41.6%, and 39.8% respectively, and their respective 90-day death rates were 22.8%, 15.1%, and 10.9%. High TI groups (TI 80, 90, >90) had 90-day transplantation rates of 53.7%, 64.3%, and 73.9%, respectively, and 90-day death rates of 5.9%, 6.5%, and 6.7% respectively. As TI increased, the likelihood of transplantation increased and that of death decreased. Low-TI groups represent the disenfranchised candidates.

CONCLUSIONS

The TI identifies disenfranchised candidates on the adult liver transplant waitlist. This is the subgroup that would benefit the most from efforts to increase access to transplantation.

Heart and lung organ offer acceptance practices of transplant programs are associated with waitlist mortality and organ yield

Variation in heart and lung offer acceptance practices may affect numbers of transplanted organs and create variability in waitlist mortality. To investigate these issues, offer acceptance ratios, or adjusted odds ratios, for heart and lung transplant programs individually and for all programs within donation service areas (DSAs) were estimated using offers from donors recovered July 1, 2016, and June 30, 2017. Logistic regressions estimated the association of DSA-level offer acceptance ratios with donor yield and local placement of organs recovered in the DSA. Competing risk methodology estimated the association of program-level offer acceptance ratios with incidence and rate of waitlist removals due to death or becoming too sick to undergo transplant. Higher DSA-level offer acceptance was associated with higher yield (odds ratios [ORs]: lung, _1.04 1.11_1.19 ; heart, _1.09 1.21_1.35 ) and more local placement of transplanted organs (ORs: lung, _1.01 1.12_1.24 ; heart, _1.47 1.69_1.93 ). Higher program-level offer acceptance was associated with lower incidence of waitlist removal due to death or becoming too sick to undergo transplant (hazard ratios [HRs]: heart, _0.80 0.86_0.93 ; lung, _0.67 0.75_0.83 ), but not with rate of waitlist removal (HRs: heart, _0.91 0.98_1.06 ; lung, _0.89 0.99_1.10 ). Heart and lung offer acceptance practices affected numbers of transplanted organs and contributed to program-level variability in the probability of waitlist mortality.

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.

Quality measurement and improvement in liver transplantation

There is growing interest in the quality of health care delivery in liver transplantation. Multiple stakeholders, including patients, transplant providers and their hospitals, payers, and regulatory bodies have an interest in measuring and monitoring quality in the liver transplant process, and understanding differences in quality across centres. This article aims to provide an overview of quality measurement and regulatory issues in liver transplantation performed within the United States. We review how broader definitions of health care quality should be applied to liver transplant care models. We outline the status quo including the current regulatory agencies, public reporting mechanisms, and requirements around quality assurance and performance improvement (QAPI) activities. Additionally, we further discuss unintended consequences and opportunities for growth in quality measurement. Quality measurement and the integration of quality improvement strategies into liver transplant programmes hold significant promise, but multiple challenges to successful implementation must be addressed to optimise value.

Offer acceptance practices and geographic variability in allocation model for end-stage liver disease at transplant

Offer acceptance practices may cause geographic variability in allocation Model for End-Stage Liver Disease (aMELD) score at transplant and could magnify the effect of donor supply and demand on aMELD variability. To evaluate these issues, offer acceptance practices of liver transplant programs and donation service areas (DSAs) were estimated using offers of livers from donors recovered between January 1, 2016, and December 31, 2016. Offer acceptance practices were compared with liver yield, local placement of transplanted livers, donor supply and demand, and aMELD at transplant. Offer acceptance was associated with liver yield (odds ratio, 1.32; P < 0.001), local placement of transplanted livers (odds ratio, 1.34; P < 0.001), and aMELD at transplant (average aMELD difference, -1.62; P < 0.001). However, the ratio of donated livers to listed candidates in a DSA (ie, donor-to-candidate ratio) was associated with median aMELD at transplant (r = -0.45; P < 0.001), but not with offer acceptance (r = 0.09; P = 0.50). Additionally, the association between DSA-level donor-to-candidate ratios and aMELD at transplant did not change after adjustment for offer acceptance. The average squared difference in median aMELD at transplant across DSAs was 24.6; removing the effect of donor-to-candidate ratios reduced the average squared differences more than removing the effect of program-level offer acceptance (33% and 15% reduction, respectively). Offer acceptance practices and donor-to-candidate ratios independently contributed to geographic variability in aMELD at transplant. Thus, neither offer acceptance nor donor-to-candidate ratios can explain all of the geographic variability in aMELD at transplant. Liver Transplantation 24 478-487 2018 AASLD.

Kidney allograft offers: Predictors of turndown and the impact of late organ acceptance on allograft survival

There is growing interest in understanding patterns of organ acceptance and reducing discard. Little is known about how donor factors, timing of procurement, and geographic location affect organ offer decisions. We performed a retrospective cohort study of 47 563 deceased donor kidney match-runs from 2007 to 2013. Several characteristics unrelated to allograft quality were independently associated with later acceptance in the match-run: Public Health Service increased-risk donor status (adjusted odds ratio [aOR] 2.49, 95% confidence interval [CI] 2.29-2.69), holiday or weekend procurement (aOR 1.11, 95% CI 1.07-1.16), shorter donor stature (aOR 1.53 for <150 cm vs reference >180 cm, 95% CI 1.28-1.94), and procurement in an area with higher intensity of market competition (aOR 1.71, 95% CI 1.62-1.78) and with the longest waiting times (aOR 1.41, 95% CI 1.34-1.49). Later acceptance in the match-run was associated with delayed graft function but not all-cause allograft failure (adjusted hazard ratio 1.01, 95% CI 0.96-1.07). Study limitations include a lack of match-run data for discarded organs and the possibility of sequence inaccuracies for some nonlocal matches. Interventions are needed to reduce turndowns of viable organs, especially when decisions are driven by infectious risk, weekend or holiday procurement, geography, or other donor characteristics unrelated to allograft quality.

What patients and members of their support networks ask about transplant program data

Transplant patients often seek specific data and statistics to inform medical decision making; however, for many relevant measures, patient-friendly information is not available. Development of patient-centered resources should be informed by patient needs. This study used qualitative document research methods to review 678 detailed Scientific Registry of Transplant Recipients (SRTR) entries and summary counts of 55 362 United Network for Organ Sharing (UNOS) entries to provide a better understanding of what was asked and what requests were most common. Incoming call and email logs maintained by SRTR and UNOS were reviewed for 2010-2015. Patients sought a wide range of information about outcomes, waiting times, program volumes, and willingness to perform transplants in candidates with specific diseases or demographics. Patients and members of their support networks requested explanation of complex information, such as actual-vs-expected outcomes, and of general transplant processes, such as registering on the waiting list or becoming a living donor. They sought transplant program data from SRTR and UNOS, but encountered gaps in the information they wanted and occasionally struggled to interpret some data. These findings were used to identify potential gaps in providing program-specific data and to enhance the SRTR website (www.srtr.org) with more patient-friendly information.

Outcomes and disparities in liver transplantation will be improved by redistricting-cons

PURPOSE OF REVIEW

Over the last 2 years, the liver transplant community has been debating a proposal to redraw the maps of organ distribution. The basis for these proposed changes is reported disparities in severity of illness at transplantation across the USA - however, this is based on the allocation model for end-stage liver disease score. In this review, we provide a critical overview of the redistribution proposal, its flaws and how it may worsen outcomes and exacerbate disparities in liver transplantation.

RECENT FINDINGS

The main findings we highlight are data questioning the disparity metric used to justify the redistribution. We also review data published in recent articles and presented at public forums questioning whether there truly are disparities in access to transplant care among the broader population with liver disease, and whether disparities even getting to the waitlist are important and not to be ignored.

SUMMARY

This review article highlights major methodological and policy flaws with the current redistribution proposal. We demonstrate how the waitlist disparities that the proposal is intended to fix are not as they seem. Furthermore, if this proposal is passed, outcomes of liver transplantation nationally may worsen, and disparities for those with limited access to healthcare will worsen.

Influence of kidney offer acceptance behavior on metrics of allocation efficiency

We investigated associations of deceased donor kidney offer acceptance with likelihood of the kidney being discarded, cold ischemia time at transplant (CIT), and likelihood of the kidney being exported outside the donation service area (DSA). We used kidney offers from donors in the Scientific Registry of Transplant Recipients July 1, 2015-June 30, 2016, and a stratified logistic regression to estimate odds ratios of acceptance for candidates wait-listed in a DSA. We estimated associations between these ratios and likelihood of discard or export and CIT at transplant. Approximately 0.50 kidneys were discarded per donor; lower DSA-specific offer acceptance ratios were associated with more discards (R=-0.20; P=0.006). For a median donor, the DSA with the highest acceptance ratio would place 0.12 more kidneys per donor than the DSA with the lowest ratio. Low acceptance ratios were associated with higher CIT (R=-0.23; P<0.001). For the median donor, CIT was 2.9 hours shorter for the DSA with the highest versus lowest acceptance ratio. Low acceptance ratios were associated with more exports (R=-0.43; P<0.001); the probability was 15% higher for a median donor in the DSA with the lowest versus highest acceptance ratio. Improving lower-than-expected offer acceptance would likely reduce discards, CIT, and exports.