The Landscape of Status 1B by Exception for Pediatric Acute on Chronic Liver Failure—High Risk, High Mortality, and Low Transplant Rate

ABSTRACT Background Acute on chronic liver failure (ACLF) leads to increased mortality from multiorgan failure. Methods Our objective was to evaluate differences in characteristics and outcomes of children with ACLF listed as Status 1B for liver transplantation (LT) by (1) explicit criteria or (2) exception. We identified 367 children with ACLF who were listed Status 1B for LT in the United Network for Organ Sharing (UNOS) database between January 2007 and March 2019. Children with metabolic diseases and malignancies were excluded. Results Of 367 children with ACLF listed as Status 1B, 110 (30%) were listed by exception. There were no differences between groups in age, sex, race/ethnicity, or diagnosis. Incidence of cumulative organ failures and MELD/PELD scores were lower in the exception group at waitlisting and at waitlist removal (all p < 0.05). There were regional differences in exception utilization with regions 2 and 10 having a higher proportion of exception listing (43% and 47% vs. overall 30%, p = 0.03). There was no difference in transplantation rate, recovery without transplant, or pre−/post‐LT mortality between groups. Narrative summaries in the exception group cited the critical or refractory nature of the patient's illness, with increased risk of waitlist mortality as reasons for urgent LT. Conclusion Our study showed that one third of children with ACLF listed as Status 1B receive this designation using exception criteria. Children listed by exception had similar pre−/post‐LT mortality compared to the explicit group. Further study is needed to understand why these children are at higher risk than expected.