Liver transplantation (LT) remains the definitive treatment for selected acute and chronic liver diseases, offering improved survival and quality of life (QoL) [1]. Given the ongoing shortage of donor organs, patient selection must be based on transparent and equitable criteria to ensure fair allocation [2, 3]. In the United Kingdom (UK), the Liver Advisory Group (LAG), under NHS Blood and Transplant (NHSBT), defines standard listing criteria across four categories: acute liver failure (ALF), chronic liver disease (CLD), variant syndromes, and primary liver cancer. These aim to prioritise patients with the greatest need and likelihood of benefit [4].

However, some patients with urgent or complex presentations fall outside these criteria and are ineligible for routine listing [5, 6]. To address this, the UK established the National Appeals Panel (NAP) in January 2011, a multidisciplinary body that reviews appeals for such exceptional cases [7]. Through structured, case-by-case deliberation, the NAP ensures LT is not denied to individuals with rare but legitimate indications. This centralised process promotes consistency, accountability, and fairness in exception handling [8].

Despite the NAP’s critical role in the UK transplant framework, limited evidence exists on its outcomes, particularly long-term graft and patient survival following successful appeals. Similarly, the characteristics and outcomes of declined cases or those not proceeding to transplant despite approval are poorly described. Understanding these patterns is vital to evaluate the NAP’s effectiveness and inform future revisions to national policy [8].

This retrospective study evaluates all appeals submitted to the NAP, analysing case characteristics, approval outcomes, transplant rates, and post-transplant patient and graft survival. We also explore reasons for declined appeals and recurring themes that may guide future policy development.

The present study provides the first comprehensive national analysis of the UK National Appeals Panel (NAP) for LT, covering a decade of experience since its inception in 2011. Our findings demonstrate that the NAP fulfils its intended purpose: extending access to transplantation for patients who fall outside conventional criteria while maintaining excellent graft and patient outcomes. The high approval rate, particularly for super-urgent appeals, alongside the outstanding post-transplant survival, highlights the effectiveness of this national mechanism in balancing equity, clinical benefit, and stewardship of scarce donor organs.

For context, national NHSBT outcome data from August 2025 report 1- and 5-year adult patient survival rates of approximately 95% and 83% for elective, first deceased-donor LTs performed for standard indications (noting that national figures include a small number of NAP cases) [9]. In comparison, NAP-approved patients in our cohort achieved excellent outcomes, with 1- and 5-year graft survival of 98% and 90%, respectively. These findings indicate that carefully selected exceptional-case candidates can achieve outcomes comparable to, and in some instances exceeding, national benchmarks despite falling outside conventional listing criteria.

Across the study period, nearly nine out of ten appeals were approved, reflecting effective triage at the time of submission and suggesting that centres use the NAP judiciously for well-selected patients. Approval was notably higher for super-urgent appeals (92.9%) compared with elective cases (79.5%). This difference aligns with the strict, nationally defined criteria governing super-urgent listing in the UK. According to NHSBT Policy POL195/7, super-urgent status is limited to patients with fulminant hepatic failure or rapidly progressive early graft failure, where death is expected within hours to days without transplantation [6]. Such cases undergo objective assessment against mandated biochemical and clinical thresholds and are used sparingly by centres for the most compelling, time-critical situations. The higher approval rate thus reflects the uniformly high mortality risk and stringent eligibility criteria, rather than any bias related to appeal status. NAP decisions for these cases remain based on established national criteria and evaluation of expected post-transplant benefit. In contrast, elective appeals involve more heterogeneous conditions with less predictable trajectories, prompting a more cautious appraisal by the panel [10, 11]. This distinction demonstrates a robust system in which both urgency and expected survival inform fair decision-making [12].

Patients approved and transplanted following appeal represented a broad spectrum of diagnoses, including post-transplant complications (21.1%), cholestatic liver disease (21.1%), acute liver failure (13.7%), and metabolic/variant conditions (33.7%). Notably, only a minority (10.5%) involved HCC with favourable biology [13, 14]. These patterns highlight the important role of the NAP in addressing rare, atypical, or post-transplant scenarios that are excluded from standard criteria but nonetheless compatible with good outcomes. The inclusion of young patients with severe metabolic or vascular syndromes is particularly striking, as these groups often face devastating morbidity without transplantation but would not otherwise qualify under fixed listing criteria [15].

Despite the clinical severity of many cases, nearly half transplanted under super-urgent status, with 20.0% ventilated and 25.3% on renal support at the time of surgery, outcomes were excellent. Graft survival reached 95% at 1 year and 85% at 5 years, while patient survival was 98% and 90% respectively. These results are at least equivalent to, and in some instances superior to, national outcomes for standard indications, suggesting that NAP approval successfully selects patients who are both high-need and high-benefit [16, 17]. The relatively low rates of vascular (4.2%) and biliary (4.2%) complications reinforce the appropriateness of these transplants, even under urgent or complex circumstances.

A substantial minority of approved patients (19.5%) did not undergo transplantation, most often because of clinical deterioration on the waiting list (43.5% of non-transplanted approvals). Others were removed for improvement, or unspecified reasons. This highlights the ongoing challenge of organ scarcity: even when approval is granted, timely transplantation is not guaranteed. Median UKELD was slightly lower among those not transplanted (48 vs. 51), but rates of malignancy indications were higher (17.4% vs. 10.5%). This pattern suggests that patients with cancer, despite favourable biology, may face greater difficulty securing an appropriate graft before disease progression [18, 19]. Strategies to optimise organ utilisation, including broader use of DCD with or without NRP, machine perfused marginal grafts, and LDLT, may help reduce waiting list mortality in this high-risk group [20–22].

The NAP declined 19 adult appeals (13.7%), the majority (63.0%) involving unfavourable oncological profiles such as recurrent or advanced HCC, cholangiocarcinoma (CCA), or metastatic neuroendocrine tumours (NET). These decisions align with international consensus that adverse tumour biology predicts poor post-transplant survival and unacceptable recurrence rates [23, 24]. A smaller number of non-malignant cases, such as severe alcoholic hepatitis, vanishing bile duct syndrome, and atypical ALF were declined due to uncertain benefit or lack of supporting precedent [25–27]. Although difficult, these rejections reflect the panel’s essential gatekeeping role in protecting scarce organs from being used where futility or poor outcomes are likely. Importantly, the process provides transparency and consistency across the UK, avoiding ad hoc or centre-specific variation that could undermine equity [28, 29].

Transplant oncology is an evolving field, with expanding indications for LT in select high-risk malignancies, including unresectable colorectal liver metastases (CRLM), NETs and CCAs [30]. Recent studies have demonstrated that, in carefully selected patients, LT can offer survival benefits in these groups, leading to a cautious expansion of transplant criteria. These developments have raised complex ethical considerations regarding organ allocation, balancing potential survival benefits against scarcity of donor organs [31]. Within this context, the NAP has historically adopted a cautious approach to high-risk oncologic indications, reflecting the evolving evidence base and ethical deliberations. Our dataset captures this gradual adoption, highlighting how the appeals process accommodated these nuanced, high-risk cases during the study period, and providing insight into real-world clinical decision-making in transplant oncology.

The UK NAP shares similarities with the U.S. National Liver Review Board (NLRB) and comparable European mechanisms for exceptional case review [32, 33]. However, unlike regional or institutional committees operating in many European countries, the NAP represents the only nationally centralised, multidisciplinary structure with standardised governance and voting across all UK LT centres. Comparable frameworks include the European Reference Network for Rare Liver Diseases (ERN-RARE-LIVER) and other regional appeal systems [34, 35].

Recent U.S. experience with the transition from regional review boards to a single NLRB has demonstrated reduced adjudication times, comparable waitlist outcomes between patients with and without exception scores, and greater process efficiency and equity, while maintaining rigorous scrutiny of exception requests [32]. Whereas many countries still rely on regional or centre-level discretion [34, 35], the UK ensures national consistency by requiring case triage by the Chair and then approval from at least four of seven transplant centres for each case. Our findings suggest this design achieves an appropriate balance: high approval rates for genuine exceptional need, but regular and principled rejections for cases with poor prognosis. This may serve as a model for other countries seeking to harmonise fairness with flexibility in organ allocation and to promote international standardisation of extended-criteria listing processes [36, 37].

Repeated successful appeals for certain conditions, such as acute intermittent porphyria, metabolic syndromes, and selected post-transplant complications, does raise the question of whether these should be incorporated into routine national listing criteria [38, 39]. Doing so would reduce the burden of appeals, expedite access for patients, and provide greater clarity for clinicians. Similarly, closer integration of tumour biology markers into listing criteria for HCC may refine the balance between excluding poor-risk cases and enabling access for those with favourable profiles beyond size/number thresholds [40].

The outcomes of paediatric appeals to the NAP demonstrate the effectiveness of the process, with all appeals approved and nine of ten children successfully proceeding to transplantation. This highlights that once approval was granted, access to transplantation was generally achieved, even in complex and high-risk cases. Importantly, six children remain alive with good medium- to long-term outcomes, including several beyond 5 years post-transplant, reflecting the durability of graft function in survivors. The spectrum of indications ranging from malignancy and acute liver failure to metabolic and haematological disorders, illustrates the capacity of the system to support the diversity in paediatric liver conditions, including urgent and super-urgent cases. These results underscore the value of a responsive appeals process and highlight the potential for excellent outcomes when timely listing is combined with close pre- and post-transplant monitoring [41, 42].

Acute-on-chronic liver failure (ACLF) represents a potential indication for NAP submission, particularly for patients at high risk of short-term mortality. Although the number of appeals explicitly recorded as ACLF in our dataset was small, several cases may have followed ACLF-like clinical trajectories, reflecting acute decompensation on chronic liver disease. During the study period, there was no national ACLF-specific listing policy; centres therefore occasionally utilised the NAP pathway to allow timely consideration of these high-risk patients. This highlights both the evolving spectrum of indications for exceptional listing and the need for clear national guidance for ACLF in the context of transplant allocation.

This study has several strengths, including its national scope, comprehensive inclusion of all appeals, and robust survival analysis with long-term follow-up. By building on prior descriptive reports, it is the first to provide outcome data that clearly demonstrate the legitimacy and effectiveness of the NAP. Nonetheless, some limitations should be noted. Our analysis is descriptive and does not include a matched comparator cohort of patients listed through standard criteria. Therefore, while the NAP appears to facilitate access for well-selected patients, we cannot definitively conclude that it ensures equity. This limitation should be considered when interpreting our findings. Reliance on registry data restricted detail on QoL, functional outcomes, and precise reasons for non-transplantation, while incomplete or missing entries may have limited the depth of subgroup analyses. The relatively small number of declined cases reduced statistical power to explore this group, and the retrospective design precludes causal inference. Temporal bias may also have been introduced, as changes in listing policy, practice, panel, and organ availability over the 10-year study could have influenced case mix and outcomes. In addition, not all potential appeals may have reached the NAP stage, as some cases may have been resolved informally between centres or via the LAG. Future work should focus on prospective audit, capture patient-reported outcomes, and assess evolving trends to ensure equitable access and ongoing effectiveness of the appeals process.

This national review confirms the value of the NAP in ensuring fair and effective access to liver transplantation for exceptional cases. Despite high illness severity, transplanted patients achieved excellent long-term outcomes, validating the careful scrutiny applied during appeals. The panel’s willingness to decline inappropriate cases further demonstrates its integrity as a gatekeeper of scarce donor organs. Refining national policy to incorporate conditions repeatedly approved at appeal, while continuing to monitor outcomes, will strengthen the system further. Ultimately, the NAP exemplifies how a centralised, multidisciplinary mechanism can reconcile compassion for individual patients with responsible stewardship of limited transplant resources.