One Size Does Not Fit All--Regional Variation in the Impact of the Share 35 Liver Allocation Policy

Impact of Share 35 liver transplantation allocation in Australia and New Zealand

Patients with high model for end-stage liver disease (MELD) scores waiting for liver transplantation in Australia and New Zealand (ANZ) have had limited access to deceased donor livers and therefore binational sharing of livers, for patients with a MELD score ≥35 was introduced in February 2016. Waiting list mortality, post-transplant outcomes and intention-to-treat survival were compared between patients whose MELD score reached 35 on the waiting list between October 2013 and April 2015 (Pre-Share 35 group, n = 23) and patients who were Share 35 listed between February 2016 and May 2022 (Share 35 group, n = 112). There was significantly reduced waiting list mortality in share 35 listed patients in comparison to the pre-Share 35 group (11.7% vs. 52.2%, OR .120 95% CI .044-.328, P < .001). Post-transplant patient and graft survival were not significantly different between the groups (5-year patient survival 82% vs. 84%, P = .991, 5-year graft survival 82% vs. 76%, P = .543). Intention-to-treat survival was superior in the Share 35 group (HR .302, 95% CI .149-.614, P < .001). Introduction of Share 35 in ANZ resulted in a 78% risk reduction in waiting list mortality, equivalent post-transplant survival and an improvement in intention-to-treat survival.

Disparities in the Use of Older Donation After Circulatory Death Liver Allografts in the United States Versus the United Kingdom

BACKGROUND

This study aimed to assess the differences between the United States and the United Kingdom in the characteristics and posttransplant survival of patients who received donation after circulatory death (DCD) liver allografts from donors aged >60 y.

METHODS

Data were collected from the UK Transplant Registry and the United Network for Organ Sharing databases. Cohorts were dichotomized into donor age subgroups (donor >60 y [D >60]; donor ≤60 y [D ≤60]). Study period: January 1, 2001, to December 31, 2015.

RESULTS

1157 DCD LTs were performed in the United Kingdom versus 3394 in the United States. Only 13.8% of US DCD donors were aged >50 y, contrary to 44.3% in the United Kingdom. D >60 were 22.6% in the United Kingdom versus 2.4% in the United States. In the United Kingdom, 64.2% of D >60 clustered in 2 metropolitan centers. In the United States, there was marked inter-regional variation. A total of 78.3% of the US DCD allografts were used locally. One- and 5-y unadjusted DCD graft survival was higher in the United Kingdom versus the United States (87.3% versus 81.4%, and 78.0% versus 71.3%, respectively; P < 0.001). One- and 5-y D >60 graft survival was higher in the United Kingdom (87.3% versus 68.1%, and 77.9% versus 51.4%, United Kingdom versus United States, respectively; P < 0.001). In both groups, grafts from donors ≤30 y had the best survival. Survival was similar for donors aged 41 to 50 versus 51 to 60 in both cohorts.

CONCLUSIONS

Compared with the United Kingdom, older DCD LT utilization remained low in the United States, with worse D >60 survival. Nonetheless, present data indicate similar survivals for older donors aged ≤60, supporting an extension to the current US DCD age cutoff.

Impact of the Share 35 Policy on Perioperative Management and Mortality in Liver Transplantation Recipients

Background

The Share 35 policy was introduced in 2013 by the Organ Procurement and Transplantation Network (OPTN) to increase opportunities of sicker patients to access liver transplantation. However, it has the disadvantage of higher MELD score associated with adverse postoperative transplant outcomes. Early data after implementation of the Share 35 policy showed significantly poorer post-transplantation survival in some UNOS regions. We aimed to analyze the impact of Share 35 on demographics of patients, perioperative management, and perioperative mortality.

Material/Methods

A retrospective analysis of data was performed from an institutional liver transplantation cohort from 1 January 2008 to 31 December 2017. Adult patients who underwent liver transplantation before 2013 were defined as the pre-Share 35 group and the other group was defined as the post-Share 35 group. The MELD score of each patient was calculated at the time of transplantation. Perioperative mortality was defined as death within 30 days after the operation.

Results

A total of 1596 patients underwent liver transplantation. Of those, 895 recipients underwent OLT in the pre-Share 35 era and 737 in the post-Share 35 era. The median MELD score was significantly higher in the post-Share 35 group (30 vs 26, P<0.001) and 45.7% of the post-Share 35 group had MELD scores ≥35. In intraoperative management, patients required significantly more blood component transfusion, intraoperative vasopressor, and fluid replacement. Veno-venous bypass (VVB) usage was significantly higher in the post-Share 35 era (47.2% vs 38.1%, P<0.001). In the subgroup of patients with MELD scores ≥35, the median waiting time was significantly shorter (18.5 vs 14.5 days, P=0.045). Overall perioperative mortality was not significantly difference between groups (P=0.435).

Conclusions

After implementation of the Share 35 policy, we performed liver transplantation in significantly higher medical acuity patients, which required more medical resources to obtain a result comparable to that of the pre-Share 35 era.

Geographic disparities in transplantation

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Evolution of liver transplant organ allocation policy: Current limitations and future directions

Since the adoption of the model for end-stage liver disease (MELD) score for organ allocation in 2002, numerous changes to the system of liver allocation and distribution have been made with the goal of decreasing waitlist mortality and minimizing geographic variability in median MELD score at time of transplant without worsening post-transplant outcomes. These changes include the creation and adoption of the MELD-Na score for allocation, Regional Share 15, Regional Share for Status 1, Regional Share 35/National Share 15, and, most recently, the Acuity Circles Distribution Model. However, geographic differences in median MELD at time of transplant remain as well as limits to the MELD score for allocation, as etiology of liver disease and need for transplant changes. Acute-on-chronic liver failure (ACLF) is a subset of liver failure where prevalence is rising and has been shown to have an increased mortality rate and need for transplantation that is under-demonstrated by the MELD score. This underscores the limitations of the MELD score and raises the question of whether MELD is the most accurate, objective allocation system. Alternatives to the MELD score have been proposed and studied, however MELD score remains as the current system used for allocation. This review highlights policy changes since the adoption of the MELD score, addresses limitations of the MELD score, reviews proposed alternatives to MELD, and examines the specific implications of these changes and alternatives for ACLF.

The Utility of Extended Criteria Donor Livers in High Acuity Liver Transplant Recipients

BACKGROUND

Although the use of extended criteria donor (ECD) liver allografts has gained momentum as a potential method by which to expand the donor pool, their use largely remains relegated to low acuity liver transplant (LT) recipients. Thus, we sought to examine whether such grafts also have utility in high acuity (Model for End-Stage Liver Disease [MELD] ≥ 35) recipients.

STUDY DESIGN

Extended criteria donors were defined as donor age > 60 years, hepatitis C virus positive donor, split livers, livers with cold ischemia time > 12 h, donor after cardiac death livers, or having macrosteatosis > 30%. Outcomes were compared between standard liver (SL) and ECD grafts in recipients with MELD ≥ 35.

RESULTS

Of 225 patients, 46 (20.4%) received an ECD liver and 179 (79.6%) received a SL. Extended criteria donor graft recipients had significantly higher levels of post-LT maximal transaminases and rate of early allograft dysfunction. Nonetheless, high acuity ECD graft recipients had similar short- and long-term patient survival compared to SL recipients, with 1-,3-, and 5-year survivals of 86.9%, 82.3%, 79.3% and 86.9%, 80.5%, and 75.4%, respectively (P = .674). There were also no significant differences in graft survival or rejection-free survival between the 2 groups.

CONCLUSION

The lack of inferior patient/graft survival among high acuity ECD graft recipients suggests that ECD livers present a viable method by which to expand the donor pool for this group of patients.

A Review of the Current State of Liver Transplantation Disparities

Equity in access is one of the core goals of the Organ Procurement and Transplant Network (OPTN). However, disparities in liver transplantation have been described since the passage of the National Organ Transplant Act, which established OPTN in the 1980s. During the past few decades, several efforts have been made by the United Network for Organ Sharing (UNOS) to address disparities in liver transplantation with notable improvements in many areas. Nonetheless, disparities have persisted across insurance type, sex, race/ethnicity, geographic area, and age. African Americans have lower rates of referral to transplant centers, females have lower rates of transplantation from the liver waiting list than males, and public insurance is associated with worse posttransplant outcomes than private insurance. In addition, pediatric candidates and older adults have a disadvantage on the liver transplant waiting list, and there are widespread regional disparities in transplantation. Given the large degree of inequity in liver transplantation, there is a tremendous need for studies to propose and model policy changes that may make the liver transplant system more just and equitable.

Patients with severe acute-on-chronic liver failure are disadvantaged by model for end-stage liver disease-based organ allocation policy

BACKGROUND

Mortality for patients with acute-on-chronic liver failure (ACLF) may be underestimated by the model for end-stage liver disease-sodium (MELD-Na) score.

AIM

To assess waitlist outcomes across varying grades of ACLF among a cohort of patients listed with a MELD-Na score ≥35, and therefore having similar priority for liver transplantation.

METHODS

We analysed the United Network for Organ Sharing (UNOS) database, years 2010-2017. Waitlist outcomes were evaluated using Fine and Gray's competing risks regression.

RESULTS

We identified 6342 candidates at listing with a MELD-Na score ≥35, of whom 3122 had ACLF-3. Extra-hepatic organ failures were present primarily in patients with four to six organ failures. Competing risks regression revealed that candidates listed with ACLF-3 had a significantly higher risk for 90-day waitlist mortality (Sub-hazard ratio (SHR) = 1.41; 95% confidence interval [CI] 1.12-1.78) relative to patients with lower ACLF grades. Subgroup analysis of ACLF-3 revealed that both the presence of three organ failures (SHR = 1.40, 95% CI 1.20-1.63) or four to six organ failures at listing (SHR = 3.01; 95% CI 2.54-3.58) was associated with increased waitlist mortality. Candidates with four to six organ failures also had the lowest likelihood of receiving liver transplantation (SHR = 0.61, 95% CI 0.54-0.68). The Share 35 rule was associated with reduced 90-day waitlist mortality among the full cohort of patients listed with ACLF-3 and MELD-Na score ≥35 (SHR = 0.59; 95% CI 0.49-0.70). However, Share 35 rule implementation was not associated with reduced waitlist mortality among patients with four to six organ failures (SHR = 0.76; 95% CI 0.58-1.02).

CONCLUSIONS

The MELD-Na score disadvantages patients with ACLF-3, both with and without extra-hepatic organ failures. Incorporation of organ failures into allocation policy warrants further exploration.

Liver transplantation for colorectal liver metastasis

PURPOSE OF REVIEW

The aim of this review is to discuss existing data on liver transplantation for colorectal liver metastasis, emerging controversies, and future directions.

RECENT FINDINGS

Contemporary experience with transplanting patients with liver metastasis from colon cancer is mainly derived from European centers, with a large proportion being from a single institution (SECA study), made possible in part by a relatively high donor pool. The initial results prove to be encouraging by demonstrating an overall survival advantage over unresectable patients with liver-limited disease managed with chemotherapy only. Recurrence patterns, however, suggest a need for better patient selection and treatment sequencing optimization. In North America, the main barriers in establishing similar protocols result from national liver graft shortage, which represents an issue of competing resources when indications have yet to be well defined. Evolving strategies in transplantation, such as the utilization of marginal liver grafts and living donor liver transplantation might constitute potential solutions.

SUMMARY

Evidence suggests a potential survival benefit of liver transplantation for a subset of patients with unresectable liver-limited CRLM. Further prospective trials are needed to clarify the role and feasibility of this treatment strategy in oncotransplantation.

Living Donor Liver Transplantation: Overview, Imaging Technique, and Diagnostic Considerations

OBJECTIVE. The purpose of this article is to discuss the process of becoming a liver donor, describe the surgical methods used for transplantation, and critically review preoperative and intraoperative imaging techniques. CONCLUSION. Radiologists play a vital role in ensuring the safety of living liver donors; however, consensus guidelines do not exist for imaging protocol or reporting. Standardization would provide more consistent image quality across centers, improve communication with the transplant team, and facilitate data mining for quality assurance and research.

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.

Effects of Allocating Livers for Transplantation Based on Model for End-Stage Liver Disease-Sodium Scores on Patient Outcomes

BACKGROUND & AIMS

The Model for End-stage Liver Disease and Sodium (MELD-Na) score was introduced for liver allocation in January 2016. We evaluated the effects of liver allocation, based on MELD-Na score, on waitlist and post-transplantation outcomes.

METHODS

We examined 2 patient groups from the United Network for Organ Sharing registry; the MELD-period group was composed of patients who were registered as transplant candidates from June 18, 2013 through January 10, 2016 (n = 18,850) and the MELD-Na period group was composed of patients who were registered from January 11, 2016 through September 30, 2017 (n = 14,512). We compared waitlist and post-transplantation outcomes and association with serum sodium concentrations between groups.

RESULTS

Mortality within 90 days on the liver waitlist decreased (hazard ratio [HR] 0.738, P < .001) and transplantation probability increased significantly (HR 1.217, P < .001) in the MELD-Na period. Although mild, moderate, and severe hyponatremia (130-134, 125-129, and <125 mmol/L) were independent risk factors for waitlist mortality in the MELD period (HR 1.354, 1.762, and 2.656; P < .001, P < .001, and P < .001, respectively) compared with the reference standard (135-145 mmol/L), these adverse outcomes were decreased in the MELD-Na period (HR 1.092, 1.271 and 1.374; P = .27, P = .018, and P = .037, respectively). The adjusted survival benefit of transplant recipients vs patients placed on the waitlist in the same score categories was definitive for patients with MELD-Na scores of 21-23 in the MELD-Na era (HR 0.336, P < .001) compared with MELD scores of 15-17 in the MELD era (HR 0.365, P < .001).

CONCLUSIONS

Liver allocation based on MELD-Na score successfully improved waitlist outcomes and provided significant benefit to hyponatremic patients. Given the discrepancy in transplantation survival benefit, the current rules for liver allocation might require revision.

Marked Decrease in Urgent Listing for Liver Transplantation Over Time: Evolution of Characteristics and Outcomes of Status-1 Liver Transplantation

BACKGROUND

Approximately 5% of liver transplants annually are performed urgently with "status-1" designation. This study aims to determine if the demand, characteristics, and outcome for status-1 liver transplantation has changed over time.

METHODS

We used the Scientific Registry of Transplant Patients (2003-2015) to characterize 2352 adult patients who underwent 2408 status-1 liver transplants and compared them between Era1 (2003-6/2009) and Era2 (7/2009-2015).

RESULTS

Overall, there were fewer liver transplants performed with the status-1 designation in Era2 than Era1 (1099 vs 1309). Although the number of urgent liver transplants was relatively constant with successive years, the proportion transplanted with status-1 designation decreased markedly over time. Era2 patients were older (43.2 years vs 41.7 years, P = 0.01) and less likely be ABO-incompatible (1.1% vs 2.4%, P = 0.01) or retransplant (77 vs 124, P = 0.03). In terms of disease etiology, the largest group was "acute liver failure (ALF), nonspecified" (43.4%). There was no difference in proportion with drug-induced liver injury (DILI), but the subset of herbal/dietary supplements increased in Era2 (1.3% vs 0.46%, P = 0.04). Survival was increased in Era2 in the overall cohort and for patients with autoimmune disease (P < 0.05), despite longer waiting times for this etiology (186 days vs 149 days). DILI or nonspecified ALF had shorter waiting times, and 90% were transplanted within 7 days.

CONCLUSIONS

Liver transplantation for the most urgent indications (status-1) is decreasing while survival remains excellent. Fewer incidences of ALF are classified as indeterminate, mostly as a result of increasing awareness of autoimmune hepatitis and DILI as causes of the syndrome.

Improved retransplant outcomes: early evidence of the share35 impact

BACKGROUND

Share 35 prioritizes offers of deceased donor livers to regional candidates with Model for End-Stage Liver Disease (MELD) ≥35 over local candidates with lower MELD scores. Analysis of Share35 has shown that overall 1- or 2-year post-transplant (LTx) outcomes have been unchanged while waitlist mortality has been reduced. However, these studies exclude retransplant (reLTx) recipients. This study aims to investigate the outcomes of liver retransplants in evaluating the impact of the Share35 policy.

METHODS

A retrospective analysis of data from the United Network for Organ Sharing database over the period June 2011-June 2015 was performed.

RESULTS

A total of 19,748 LTx and 312 reLTx recipients were identified. Of the LTx recipients, 9626 (48.7%) underwent transplant pre-Share 35 and 10,122 (51.3%) post-Share 35. 123 (39.4%) reLTx recipients underwent retransplantation pre-Share 35 and 189 (60.6%) post-Share 35. ReLTx recipients experienced improved 2-year graft survival post-Share 35 compared to pre-Share 35 (67% vs. 21.1%). Patient survival also improved at 2-years for reLTx recipients post-Share 35 compared to pre-Share 35 (69.2% vs. 33.1%). Transplant post-Share 35 was protective for both 2-year graft (HR = 0.669, CI = 0.454-0.985, p = 0.04) and patient (HR = 0.659, CI = 0.44-0.987, p = 0.003) survival.

CONCLUSION

Share35 is associated with improved outcomes after retransplantation.

New paradigms for organ allocation and distribution in liver transplantation

PURPOSE OF REVIEW

The 'Final Rule,' issued by the Health Resources and Service Administration in 2000, mandated that liver allocation policy should be based on disease severity and probability of death, and - among other factors - should be independent of a candidate's residence or listing. As a result, the Organ Procurement Transplantation Network/United Network for Organ Sharing (UNOS) has explored policy changes addressing geographic disparities without compromising outcomes.

RECENT FINDINGS

Major paradigm shifts are underway in U.S. liver allocation policy. New hepatocellular carcinoma exception policy incorporates tumor characteristics associated with posttransplantation outcomes, whereas a National Liver Review Board will promote a standardized process for awarding exception points. Meanwhile, following extensive debate, new allocation policy aims to reduce geographic disparity by broadening sharing to the UNOS region and 150-mile circle around the donor hospital for liver transplant candidates with a calculated model for end-stage liver disease score at least 32. Unnecessary organ travel will be reduced by granting 3 'proximity points' to candidates within the same donation service area (DSA) as a liver donor or within 150 nautical miles of the donor hospital, regardless of DSA or UNOS region.

SUMMARY

This review provides an evaluation of major policy changes in liver allocation from 2016 to 2018.

MELD as a metric for survival benefit of liver transplantation

Currently, there is debate among the liver transplant community regarding the most appropriate mechanism for organ allocation: urgency-based (MELD) versus utility-based (survival benefit). We hypothesize that MELD and survival benefit are closely associated, and therefore, our current MELD-based allocation already reflects utility-based allocation. We used generalized gamma parametric models to quantify survival benefit of LT across MELD categories among 74 196 adult liver-only active candidates between 2006 and 2016 in the United States. We calculated time ratios (TR) of relative life expectancy with transplantation versus without and calculated expected life years gained after LT. LT extended life expectancy (TR > 1) for patients with MELD > 10. The highest MELD was associated with the longest relative life expectancy (TR = _1.05 1.20_1.37 for MELD 11-15, _2.29 2.49_2.70 for MELD 16-20, _5.30 5.72_6.16 for MELD 21-25, _15.12 16.35_17.67 for MELD 26-30; _39.26 43.21_47.55 for MELD 31-34; _120.04 128.25_137.02 for MELD 35-40). As a result, candidates with the highest MELD gained the most life years after LT: 0.2, 1.5, 3.5, 5.8, 6.9, 7.2 years for MELD 11-15, 16-20, 21-25, 26-30, 31-34, 35-40, respectively. Therefore, prioritizing candidates by MELD remains a simple, effective strategy for prioritizing candidates with a higher transplant survival benefit over those with lower survival benefit.

The Impact of Share 35 Policy on Patient Survival in Patients Undergoing Liver Transplantation With Gender- and Race-Mismatched Donors: An Analysis of the United Network for Organ Sharing Registry

INTRODUCTION

The United Network for Organ Sharing (UNOS) instituted the Share 35 policy in June 2013 in order to reduce death on liver transplant waitlist. The effect of this policy on patient survival among patients with gender- and race-mismatched donors has not been examined.

RESEARCH QUESTION

To assess the impact of Share 35 policy on posttransplantation patient survival among patients with end-stage liver disease (ESLD) transplanted with gender- and race-mismatched donors.

DESIGN

A total of 16 467 adult patients with ESLD who underwent liver transplantation between 2012 and 2015 were identified from UNOS. An overall Cox proportional hazards model adjusting for demographic, clinical, and geographic factors and separate models with a dummy variable of pre- and post-Share 35 periods as well as its interaction with other factors were performed to model the effect of gender and race mismatch on posttransplantation patient survival and to compare the patient survival differences between the first 18 months of Share 35 policy to an equivalent time period before.

RESULTS

Comparison of the pre- and post-Share 35 periods did not show significant changes in the numbers of gender- and race-mismatched transplants, or the risk of death for gender-mismatched recipients. However, black recipients with Hispanic donors (hazard ratio: 0.51, 95% confidence interval, 0.29-0.90) had significantly increased patient survival after Share 35 policy took effect.

CONCLUSION

The Share 35 policy had a moderate impact on posttransplantation patient survival among recipients with racially mismatched donors according to the first 18-month experience. Future research is recommended to explore long-term transplantation.

Improved posttransplant mortality after share 35 for liver transplantation

The Share 35 policy was implemented in June 2013 to improve equity in access to liver transplantation (LT) between patients with fulminant liver failure and those with cirrhosis and severe hepatic decompensation. The aim of this study was to assess post-LT outcomes after Share 35. Relevant donor, procurement, and recipient data were extracted from the Organ Procurement and Transplantation Network/United Network for Organ Sharing database. All adult deceased donor LTs from January 1, 2010, to March 31, 2016, were included in the analysis. One-year patient survival before and after Share 35 was assessed by multivariable Cox proportional hazards analysis, with adjustment for variables known to affect graft survival. Of 34,975 adult LT recipients, 16,472 (47.1%) were transplanted after the implementation of Share 35, of whom 4,599 (27.9%) had a Model for End-Stage Liver Disease (MELD) score ≥35. One-year patient survival improved from 83.9% to 88.4% after Share 35 (P < 0.01) for patients with MELD ≥35. There was no significant impact on survival of patients with MELD <35 (P = 0.69). Quality of donor organs, as measured by a donor risk index without the regional share component, improved for patients with MELD ≥35 (P < 0.01) and worsened for patients with lower MELD (P < 0.01). In multivariable Cox regression analysis, Share 35 was associated with improved 1-year patient survival (hazard ratio, 0.69; 95% confidence interval, 0.60-0.80) in recipients with MELD ≥35.

CONCLUSION

Share 35 has had a positive impact on survival after transplantation in patients with MELD ≥35, without a reciprocal detriment in patients with lower acuity; this was in part a result of more favorable donor-recipient matching. (Hepatology 2018;67:273-281).

The donor risk index: A decade of experience

In 2006, derivation of the donor risk index (DRI) highlighted the importance of donor factors for successful liver transplantation. Over the last decade, the DRI has served as a useful metric of donor quality and has enhanced our understanding of donor factors and their impact upon recipients with hepatitis C virus, those with low Model for End-Stage Liver Disease (MELD) score, and individuals undergoing retransplantation. DRI has provided the transplant community with a common language for describing donor organ characteristics and has served as the foundation for several tools for organ risk assessment. It is a useful tool in assessing the interactions of donor factors with recipient factors and their impact on posttransplant outcomes. However, limitations of statistical modeling, choice of donor factors, exclusion of unaccounted donor and geographic factors, and the changing face of the liver transplant recipient have tempered its widespread use. In addition, the DRI was derived from data before the MELD era but is currently being applied to expand the donor pool while concurrently meeting the demands of a dynamic allocation system. A decade after its introduction, DRI remains relevant but may benefit from being updated to provide guidance in the use of extended criteria donors by accounting for the impact of geography and unmeasured donor characteristics. DRI could be better adapted for recipients with nonalcoholic fatty liver disease by examining and including recipient factors unique to this population. Liver Transplantation 23 1216-1225 2017 AASLD.

Inequity in organ allocation for patients awaiting liver transplantation: Rationale for uncapping the model for end-stage liver disease

BACKGROUND & AIM

The goal of organ allocation is to distribute a scarce resource equitably to the sickest patients. In the United States, the Model for End-stage Liver Disease (MELD) is used to allocate livers for transplantation. Patients with greater MELD scores are at greater risk of death on the waitlist and are prioritized for liver transplant (LT). The MELD is capped at 40 however, and patients with calculated MELD scores >40 are not prioritized despite increased mortality. We aimed to evaluate waitlist and post-transplant survival stratified by MELD to determine outcomes in patients with MELD >40.

METHODS

Using United Network for Organ Sharing data, we identified patients listed for LT from February 2002 through to December 2012. Waitlist candidates with MELD ⩾40 were followed for 30days or until the earliest occurrence of death or transplant.

RESULTS

Of 65,776 waitlisted patients, 3.3% had MELD ⩾40 at registration, and an additional 7.3% had MELD scores increase to ⩾40 after waitlist registration. A total of 30,369 (46.2%) underwent LT, of which 2,615 (8.6%) had MELD ⩾40 at transplant. Compared to MELD 40, the hazard ratio of death within 30days of registration was 1.4 (95% CI 1.2-1.6) for patients with MELD 41-44, 2.6 (95% CI 2.1-3.1) for MELD 45-49, and 5.0 (95% CI 4.1-6.1) for MELD ⩾50. There was no difference in 1- and 3-year survival for patients transplanted with MELD >40 compared to MELD=40. A survival benefit associated with LT was seen as MELD increased above 40.

CONCLUSIONS

Patients with MELD >40 have significantly greater waitlist mortality but comparable post-transplant outcomes to patients with MELD=40 and, therefore, should be given priority for LT. Uncapping the MELD will allow more equitable organ distribution aligned with the principle of prioritizing patients most in need. Lay summary: In the United States (US), organs for liver transplantation are allocated by an objective scoring system called the Model for End-stage Liver Disease (MELD), which aims to prioritize the sickest patients for transplant. The greater the MELD score, the greater the mortality without liver transplant. The MELD score, however, is artificially capped at 40 and thus actually disadvantages the sickest patients with end-stage liver disease. Analysis of the data advocates uncapping the MELD score to appropriately prioritize the patients most in need of a liver transplant.

Avoiding Futility in Simultaneous Liver-kidney Transplantation: Analysis of 331 Consecutive Patients Listed for Dual Organ Replacement

OBJECTIVE

We sought to evaluate outcomes and predictors of renal allograft futility (RAF-patient death or need for renal replacement therapy at 3 months) after simultaneous liver-kidney transplantation (SLKT).

BACKGROUND

Model for End-Stage Liver Disease (MELD) prioritization of liver recipients with renal dysfunction has significantly increased utilization of SLKT. Data on renal outcomes after SLKT in the highest MELD recipients are scarce, as are accurate predictors of recovery of native kidney function. Without well-established listing guidelines, SLKT potentially wastes renal allografts in both high-acuity liver recipients at risk for early mortality and recipients who may regain native kidney function.

METHODS

A retrospective single-center multivariate regression analysis was performed for adult patients undergoing SLKT (January 2004 to August 2014) to identify predictors of RAF.

RESULTS

Of 331 patients dual-listed for SLKT, 171 (52%) expired awaiting transplant, 145 (44%) underwent SLKT, and 15 (5%) underwent liver transplantation alone. After SLKT, 39% experienced delayed graft function and 20.7% had RAF. Compared with patients without RAF, RAF recipients had greater MELD scores, length of hospitalization, intraoperative base deficit, incidence of female donors, kidney and liver donor risk indices, kidney cold ischemia, and inferior overall survival. Multivariate predictors of RAF included pretransplant dialysis duration, kidney cold ischemia, kidney donor risk index, and recipient hyperlipidemia.

CONCLUSIONS

With 20% short-term loss of transplanted kidneys after SLKT, our data strongly suggest that renal transplantation should be deferred in liver recipients at high risk for RAF. Consideration for a kidney allocation variance to allow for delayed renal transplantation after liver transplantation may prevent loss of scarce renal allografts.

Same policy, different impact: Center-level effects of share 35 liver allocation

Early studies of national data suggest that the Share 35 allocation policy increased liver transplants without compromising posttransplant outcomes. Changes in center-specific volumes and practice patterns in response to the national policy change are not well characterized. Understanding center-level responses to Share 35 is crucial for optimizing the policy and constructing effective future policy revisions. Data from the United Network for Organ Sharing were analyzed to compare center-level volumes of allocation-Model for End-Stage Liver Disease (aMELD) ≥ 35 transplants before and after policy implementation. There was significant center-level variation in the number and proportion of aMELD ≥ 35 transplants performed from the pre- to post-Share 35 period; 8 centers accounted for 33.7% of the total national increase in aMELD ≥ 35 transplants performed in the 2.5-year post-Share 35 period, whereas 25 centers accounted for 65.0% of the national increase. This trend correlated with increased listing at these centers of patients with Model for End-Stage Liver Disease (MELD) ≥ 35 at the time of initial listing. These centers did not overrepresent the total national volume of liver transplants. Comparison of post-Share 35 aMELD to calculated time-of-transplant (TOT) laboratory MELD scores showed that only 69.6% of patients transplanted with aMELD ≥ 35 maintained a calculated laboratory MELD ≥ 35 at the TOT. In conclusion, Share 35 increased transplantation of aMELD ≥ 35 recipients on a national level, but the policy asymmetrically impacted practice patterns and volumes of a subset of centers. Longer-term data are necessary to assess outcomes at centers with markedly increased volumes of high-MELD transplants after Share 35. Liver Transplantation 23 741-750 2017 AASLD.

Predicting short-term survival after liver transplantation on eight score systems: a national report from China Liver Transplant Registry

To compare the performance of eight score systems (MELD, uMELD, MELD-Na. iMELD, UKELD, MELD-AS, CTP, and mCTP) in predicting the post-transplant mortality, we analyzed the data of 6,014 adult cirrhotic patients who underwent liver transplantation between January 2003 and December 2010 from the China Liver Transplant Registry database. In hepatitis B virus (HBV) group, MELD, uMELD and MELD-AS showed good predictive accuracies at 3-month mortality after liver transplantation; by comparison with other five models, MELD presented the best ability in predicting 3-month, 6-month and 1-year mortality, showing a significantly better predictive ability than UKELD and iMELD. In hepatitis C virus and Alcohol groups, the predictive ability did not differ significantly between MELD and other models. Patient survivals in different MELD categories were of statistically significant difference. Among patients with MELD score >35, a new prognostic model based on serum creatinine, need for hemodialysis and moderate ascites could identify the sickest one. In conclusion, MELD is superior to other score systems in predicting short-term post-transplant survival in patients with HBV-related liver disease. Among patients with MELD score >35, a new prognostic model can identify the sickest patients who should be excluded from waiting list to prevent wasteful transplantation.

Waitlist Outcomes of Liver Transplant Candidates Who Were Reprioritized Under Share 35

Under Share 35, deceased donor (DD) livers are offered regionally to candidates with Model for End-Stage Liver Disease (MELD) scores ≥35 before being offered locally to candidates with MELD scores <35. Using Scientific Registry of Transplant Recipients data from June 2013 to June 2015, we identified 1768 DD livers exported to regional candidates with MELD scores ≥35 who were transplanted at a median MELD score of 39 (interquartile range [IQR] 37-40) with 30-day posttransplant survival of 96%. In total, 1764 (99.8%) exports had an ABO-compatible candidate in the recovering organ procurement organization (OPO), representing 1219 unique reprioritized candidates who would have had priority over the regional candidate under pre-Share 35 allocation. Reprioritized candidates had a median waitlist MELD score of 31 (IQR 27-34) when the liver was exported. Overall, 291 (24%) reprioritized candidates had a comparable MELD score (within 3 points of the regional recipient), and 209 (72%) were eventually transplanted in 11 days (IQR 3-38 days) using a local (50%), regional (50%) or national (<1%) liver; 60 (21%) died, 13 (4.5%) remained on the waitlist and nine (3.1%) were removed for other reasons. Of those eventually transplanted, MELD score did not increase in 57%; it increased by 1-3 points in 37% and by ≥4 points in 5.7% after the export. In three cases, OPOs exchanged regional exports within a 24-h window. The majority of comparable reprioritized candidates were not disadvantaged; however, 21% died after an export.

Liver transplantation after share 35: Impact on pretransplant and posttransplant costs and mortality

Share 35 was implemented in 2013 to direct livers to the most urgent candidates by prioritizing Model for End-Stage Liver Disease (MELD) ≥ 35 patients. We aim to evaluate this policy's impact on costs and mortality. Our study includes 834 wait-listed patients and 338 patients who received deceased donor, solitary liver transplants at Mayo Clinic between January 2010 and December 2014. Of these patients, 101 (30%) underwent transplantation after Share 35. After Share 35, 29 (28.7%) MELD ≥ 35 patients received transplants, as opposed to 46 (19.4%) in the pre-Share 35 era (P = 0.06). No significant difference in 90-day wait-list mortality (P = 0.29) nor 365-day posttransplant mortality (P = 0.68) was found between patients transplanted before or after Share 35. Mean costs were $3,049 (P = 0.30), $5226 (P = 0.18), and $10,826 (P = 0.03) lower post-Share 35 for the 30-, 90-, and 365-day pretransplant periods, and mean costs were $5010 (P = 0.41) and $5859 (P = 0.57) higher, and $9145 (P = 0.54) lower post-Share 35 for the 30-, 90-, and 365-day posttransplant periods. In conclusion, the added cost of transplanting more MELD ≥ 35 patients may be offset by pretransplant care cost reduction. Despite shifting organs to critically ill patients, Share 35 has not impacted mortality significantly. Liver Transplantation 23:11-18 2017 AASLD.