Changing Dynamics in Liver Allocation: Donor and Recipient Traits Pre- and Post Acuity Circle Implementation.

BACKGROUND: The Acuity Circle (AC) allocation model for liver transplantation was implemented in 2020 to address geographic disparities in organ access. The policy improves equity and waitlist outcomes by prioritizing disease severity and reducing regional boundaries. This study reviews transplant metrics and donor and recipient characteristics in the pre- and post-AC implementation era. METHODS: Data from the National Standard Transplant Analysis and Research (STAR) file were analyzed for liver transplants performed between February 4, 2017, and February 3, 2023. Donor and recipient variables were assessed using chi-squared and t-tests. Geographic trends and changes in transplant volumes were analyzed.  Results: Following the AC implementation, transplant volume rose by 10%, with a 558% national allocation increase and a 34% local allocation decrease (p<0.001), with an increase in average distance from the donor hospital to the transplant center. Cold ischemic time increased from 5.74 to six hours (p<0.001), while the average waitlist time decreased from 232 to 182 days (p<0.001). High-severity patients received more transplants, with MELD scores rising from 23.1 to 24.7 (p<0.001).  Conclusions: The AC policy was associated with altered transplant allocation patterns, improved matching based on medical urgency, and reduced waitlist times. However, increased cold ischemic times and travel distances highlighted logistic challenges. While early trends show progress toward equity, further research is needed to address long-term effects and persistent geographic disparities.