Evaluation and selection of the liver transplant candidate: updates on a dynamic and evolving process

Outcomes and Resource Utilization in Liver Transplant Recipients Who Underwent Expedited Transplant Evaluation

BACKGROUND

Expedited liver transplant evaluations of critically ill patients can be challenging due to limited time for data gathering and psychosocial evaluation.

AIMS

To compare clinical outcomes between expedited and traditional transplant evaluation patients and assess for differences in outpatient resource utilization and staff burden between groups.

DESIGN

Adult liver transplant recipients who underwent transplant from 2015 to 2019 were included. Expedited evaluation was defined as time from initiating transplant evaluation to transplant listing <2 weeks. Primary outcomes included rates of graft rejection, graft failure, and death within 1-year posttransplant. Secondary outcomes included number of acute care visits, office visits, and medical record documentation made by transplant staff within 1-year posttransplant. Outcomes were compared using Cox regression models.

RESULTS

Of the 335 patients included, 92 (27.5%) were expedited and 243 (72.5%) were traditional. Expedited patients were significantly younger, had greater MELD scores, and required more inpatient care and life support at time of transplant. There was no significant difference in risk of graft rejection (HR 1.3, P = .4), graft failure (HR 1.3, P = .6), or mortality (HR 1.0, P = .9) between groups. Expedited transplant was not associated with increased healthcare or staff utilization: acute care visits (rate ratio 0.9, P = .7), office visits (β = -1.05, P = .2), and medical record documentation (β = 3.4, P = 0.4).

CONCLUSIONS

Despite being more critically ill, patients requiring expedited transplant evaluation have favorable outcomes after transplant and do not require more intensive staff time and resources compared to traditional candidates.

Liver Transplantation and the Elderly Candidate: Perioperative Considerations

Pioneered by Thomas Starzl in the early 1970s, liver transplant (LT) is nowadays often considered a final intervention and standard of care to cure many forms of acute and chronic end-stage liver diseases. Started in recipients younger than 60 years old, LT indications are now much broader, and at least, one-fifth of the candidates are older than 65 years. Problems associated with ageing and frailty in LT recipients and their impact on the entire perioperative course are discussed according to a modern anesthesiological perspective and the anesthesiologist covering the role of the perioperative (transplant) physician.

Optimizing liver transplant prioritization for hepatocellular carcinoma through risk stratification

PURPOSE OF REVIEW

In the United States, candidates with hepatocellular carcinoma (HCC) meeting standardized qualifying criteria receive similar priority on the liver transplant waiting list through Model for End-Stage Liver Disease exception points, without consideration of the dropout risk or relative expected benefit from liver transplantation. A more nuanced allocation scheme for HCC is needed to better represent the individual urgency for liver transplant and optimize organ utility. In this review, we discuss the development of HCC risk prediction models for practical use in liver allocation.

RECENT FINDINGS

HCC is a heterogenous disease that requires improved risk stratification for patients who fall within current transplant eligibility criteria. Several models have been proposed, though none have been adopted in clinical practice or liver allocation to date, due to various limitations.

SUMMARY

Improved HCC risk stratification for liver transplant candidates is needed to more accurately represent their urgency for transplant, with continued attention to the potential impact on post-liver transplant outcomes. Plans to implement a continuous distribution model for liver allocation in the United States may provide an opportunity to re-consider a more equitable allocation scheme for patients with HCC.

Association of Body Surface Area With Access to Deceased Donor Liver Transplant and Novel Allocation Policies

Importance

Small waitlist candidates are significantly less likely than larger candidates to receive a liver transplant.

Objective

To investigate the magnitude of the size disparity and test potential policy solutions.

Design, Setting, and Participants

A decision analytical model was generated to match liver transplant donors to waitlist candidates based on predefined body surface area (BSA) ratio limits (donor BSA divided by recipient BSA). Participants included adult deceased liver transplant donors and waitlist candidates in the Organ Procurement and Transplantation Network database from June 18, 2013, to March 20, 2020. Data were analyzed from January 2021 to September 2021.

Exposures

Candidates were categorized into 6 groups according to BSA from smallest (group 1) to largest (group 6). Waitlist outcomes were examined. A match run was created for each donor under the current acuity circle liver allocation policy, and the proportion of candidates eligible for a liver based on BSA ratio was calculated. Novel allocation models were then tested.

Main Outcomes and Measures

Time on the waitlist, assigned Model for End-Stage Liver Disease (MELD) score, and proportion of patients undergoing a transplant were compared by BSA group. Modeling under the current allocation policies was used to determine baseline access to transplant by group. Simulation of novel allocation policies was performed to examine change in access.

Results

There were 41 341 donors (24 842 [60.1%] male and 16 499 [39.9%] female) and 84 201 waitlist candidates (53 724 [63.8%] male and 30 477 [36.2%] female) in the study. The median age of the donors was 42 years (IQR, 28-55) and waitlist candidates, 57 years (IQR, 50-63). Females were overrepresented in the 2 smallest BSA groups (7100 [84.0%] and 7922 [61.1%] in groups 1 and 2, respectively). For each increase in group number, waitlist time decreased (234 days [IQR, 48-700] for group 1 vs 179 days [IQR, 26-503] for group 6; P < .001) and the proportion of the group undergoing transplant likewise improved (3890 [46%] in group 1 vs 4932 [57%] in group 6; P < .001). The smallest 2 groups of candidates were disadvantaged under the current acuity circle allocation model, with 37% and 7.4% fewer livers allocated relative to their proportional representation on the waitlist. Allocation of the smallest 10% of donors (by BSA) to the smallest 15% of candidates overcame this disparity, as did performing split liver transplants.

Conclusions and Relevance

In this study, liver waitlist candidates with the smallest BSAs had a disadvantage due to size. Prioritizing allocation of smaller liver donors to smaller candidates may help overcome this disparity.

Liver transplantation for alcohol-associated hepatitis

PURPOSE OF REVIEW

Early liver transplantation is emerging as a treatment option for severe alcohol-associated hepatitis refractory to pharmacotherapies. This review outlines the current status of transplantation for alcohol-associated hepatitis and the treatment of alcohol use disorder after liver transplantation.

RECENT FINDINGS

Rates of early liver transplantation for alcohol-associated hepatitis are increasing with significant heterogeneity in practices across the Unites States. Recent studies have demonstrated a substantial survival benefit in patients transplanted for alcohol-associated hepatitis with improved outcomes in early vs. late transplantation, first vs. prior hepatic decompensation, and posttransplant abstinence/delayed relapse vs. early return to alcohol use. Several prediction algorithms have been developed to ascertain patients' risk of alcohol relapse and aid in candidate selection, though data on treatment of alcohol use disorders in transplant recipients remains limited.

SUMMARY

Although controversial, early liver transplantation for severe alcohol-associated hepatitis has shown to be a lifesaving intervention. Additional research is needed to evaluate its long-term outcomes, optimize candidate selection, and understand treatment of alcohol use disorder posttransplant.

Building a Utility-based Liver Allocation Model in Preparation for Continuous Distribution

Background.

The current model for end-stage liver disease-based liver allocation system in the United States prioritizes sickest patients first at the expense of long-term graft survival. In a continuous distribution model, a measure of posttransplant survival will also be included. We aimed to use mathematical optimization to match donors and recipients based on quality to examine the potential impact of an allocation system designed to maximize long-term graft survival.

Methods.

Cox proportional hazard models using organ procurement and transplantation network data from 2008 to 2012 were used to place donors and waitlist candidates into 5 groups of increasing risk for graft loss (1—lowest to 5—highest). A mixed integer programming optimization model was then used to generate allocation rules that maximized graft survival at 5 and 8 y.

Results.

Allocation based on mathematical optimization improved 5-y survival by 7.5% (78.2% versus 70.7% in historic cohort) avoiding 2271 graft losses, and 8-y survival by 9% (71.8% versus 62.8%) avoiding 2725 graft losses. Long-term graft survival for recipients within a quality group is highly dependent on donor quality. All candidates in groups 1 and 2 and 43% of group 3 were transplanted, whereas none of the candidates in groups 4 and 5 were transplanted.

Conclusions.

Long-term graft survival can be improved using a model that allocates livers based on both donor and recipient quality, and the interaction between donor and recipient quality is an important predictor of graft survival. Considerations for incorporation into a continuous distribution model are discussed.