Current status of waitlist mortality and transplant probability for adult candidates with chronic end-stage liver disease for deceased donor liver transplantation under the Model for End-Stage Liver Disease score-based allocation policy in Japan
摘要
In Japan’s deceased-donor liver transplantation (DDLT), a new allocation policy based on the Model for End-Stage Liver Disease (MELD) score, including the exceptional MELD system (Ex-MELD), which periodically assigns additional points to the basal MELD score, was implemented in May 2019. We assessed the current state of this system for adult candidates with chronic end-stage liver disease.
MethodsAdult candidates (≥ 18 years) registered in the Japan Organ Transplant Network for DDLT as Status 2 cases (including chronic end-stage liver disease patients) between May 2019 and April 2023 were evaluated. We divided them into the MELD, Ex-MELD (major) [start 16 points, 2 points by 180 days], and Ex-MELD [hepatocellular carcinoma (HCC)] groups. Transplant probability and waitlist mortality rates were compared using competing risk analyses. The annual proportion of DDLT and the transition of median MELD at transplantation were also investigated.
ResultsThere were 757 candidates in MELD,126 in Ex-MELD (major), and 99 in Ex-MELD (HCC) groups. The transplant probability rates were not significantly different (3-year transplant probability rate; MELD: 24.0% vs. Ex-MELD (major): 21.0% vs. Ex-MELD (HCC): 24.1%). The rate in the Ex-MELD (major) increased dramatically as the waiting period lengthened. The waitlist mortality rates in the Ex-MELD (major) group were significantly lower (3-year waitlist mortality rate; MELD: 50.5% vs. Ex-MELD (major): 25.0% vs. Ex-MELD (HCC): 57.0%). Although the proportion of Ex-MELD (major) increased yearly in the transplanted cases, the median MELD at transplantation did not change significantly.
ConclusionsWe clearly showed the current status of adult Status 2 candidates.