A coordinated national UK liver transplant program response, prioritising waitlist recipients with the highest need, provided excellent outcomes during the first wave of the COVID-19 pandemic

Effect of recipient age on prioritisation for liver transplantation in the UK: a population-based modelling study

BACKGROUND

Following the introduction of an algorithm aiming to maximise life-years gained from liver transplantation in the UK (the transplant benefit score [TBS]), donor livers were redirected from younger to older patients, mortality rate equalised across the age range and short-term waiting list mortality reduced. Understanding age-related prioritisation has been challenging, especially for younger patients and clinicians allocating non-TBS-directed livers. We aimed to assess age-related prioritisation within the TBS algorithm by modelling liver transplantation prioritisation based on data from a UK transplant unit and comparing these data with other regions.

METHODS

In this population-based modelling study, serum parameters and age at liver transplantation assessment of patients attending the Scottish Liver Transplant Unit, Edinburgh, UK, between December, 2002, and November, 2023, were combined with representative synthetic data to model TBS survival predictions, which were compared according to age group (25-49 years vs ≥60 years), chronic liver disease severity, and disease cause. Models for end-stage liver disease (UKELD [UK], MELD [Eurotransplant region], and MELD 3.0 [USA]) were used as validated comparators of liver disease severity.

FINDINGS

Of 2093 patients with chronic liver disease, 1808 (86%) had complete datasets and liver disease parameters consistent with eligibility for the liver transplant waiting list in the UK (UKELD ≥49). Disease severity as assessed by UKELD, MELD, and MELD 3.0 did not differ by age (median UKELD scores of 56 for patients aged ≥60 years vs 56 for patients aged 25-49 years; MELD scores of 16 vs 16; and MELD 3.0 scores of 18 vs 18). TBS increased with advancing age (R=0·45, p<0·0001). TBS predicted that transplantation in patients aged 60 years or older would provide a two-fold greater net benefit at 5 years than in patients aged 25-49 years (median TBS 1317 [IQR 1116-1436] in older patients vs 706 [411-1095] in younger patients; p<0·0001). Older patients were predicted to have shorter survival without transplantation than younger patients (263 days [IQR 144-473] in older patients vs 861 days [448-1164] in younger patients; p<0·0001) but similar survival after transplantation (1599 days [1563-1628] vs 1573 days [1525-1614]; p<0·0001). Older patients could reach a TBS for which a liver offer was likely below minimum criteria for transplantation (UKELD <49), whereas many younger patients were required to have high-urgent disease (UKELD >60). US and Eurotransplant programmes did not prioritise according to age.

INTERPRETATION

The UK liver allocation algorithm prioritises older patients for transplantation by predicting that advancing age increases the benefit from liver transplantation. Restricted follow-up and biases in waiting list data might limit the accuracy of these benefit predictions. Measures beyond overall waiting list mortality are required to fully capture the benefits of liver transplantation.

FUNDING

None.

Impact of the COVID-19 pandemic on liver transplant waitlist outcome in France

The objective of this study was to investigate the impact of the COVID-19 pandemic on the outcome of patients on the liver transplantation (LT) waitlist in 2020 in France, in particular, the incidence of deaths and delisting for worsening condition, depending on the allocation score component. The 2020 cohort of patients on the waiting list was compared with the 2018/2019 cohorts. 2020 saw fewer LTs than in either 2019 or 2018 (1128, 1356, and 1325, respectively), together with fewer actual brain dead donors (1355, 1729, and 1743). In 2020, deaths or delisting for worsening condition increased significantly versus 2018/2019 (subdistribution hazard ratio 1.4, 95% confidence interval [CI] 1.2-1.7), after adjustment for age, place of care, diabetes, blood type, and score component, although COVID-19-related mortality was low. This increased risk mainly concerned patients with hepatocellular carcinoma (1.52, 95% CI 1.22-1.90), with 650 MELD exception points (2.19, 95% CI 1.08-4.43), and especially those without HCC and MELD scores from 25 to 30 (3.36 [95% CI 1.82-6.18]). In conclusion, by significantly decreasing LT activity in 2020, the COVID-19 pandemic increased the number of waitlist deaths and delisting for worsening condition, and significantly more for particular components of the score, including intermediate severity cirrhosis.

Real-time assessment of liver fat content using a filter-based Raman system operating under ambient light through lock-in amplification

During liver procurement, surgeons mostly rely on their subjective visual inspection of the liver to assess the degree of fatty infiltration, for which misclassification is common. We developed a Raman system, which consists of a 1064 nm laser, a handheld probe, optical filters, photodiodes, and a lock-in amplifier for real-time assessment of liver fat contents. The system performs consistently in normal and strong ambient light, and the excitation incident light penetrates at least 1 mm into duck fat phantoms and duck liver samples. The signal intensity is linearly correlated with MRI-calibrated fat contents of the phantoms and the liver samples.