Revisiting the Prognostic Influences of Donor-Recipient Size Mismatch in Deceased Donor Liver Transplantation

Abstract

Background. Liver transplantation (LT) outcomes are influenced by donor-recipient size mismatch. This study reevaluated the impact on graft size discrepancies on survival outcomes. Methods. Data from 53389 adult LT recipients from the United Network for Organ Sharing database (2013–2022) were reviewed. The study population was divided by the body surface area index (BSAi), defined as the ratio of donor body surface area (BSA) to recipient BSA, into small-for-size (BSAi<0.78), normal-for-size (BSAi 0.78–1.24), and large-for-size (BSAi>1.24) grafts in deceased donor LT (SFSD, NFSD, and LFSD). Multivariate Cox regression and Kaplan-Meier survival analyses were conducted. Results. The frequency of size mismatch in deceased donor LT increased over the past 10 y. SFSD had significantly worse 90-d graft survival (P<0.01), and LFSD had inferior 1-y graft survival among 90-d survivors (P=0.01). SFSD was hazardous within 90 d post-LT because of vascular complications. Beyond 1 y, graft size did not affect graft survival. LFSD risk within the first year was mitigated with lower model for end-stage liver disease (MELD) 3.0 scores (<35) or shorter cold ischemia time (<8h). Conclusions. The negative impacts on donor-recipient size mismatch on survival outcomes are confined to the first year post-LT. SFSD is associated with a slight decrease in 90-d survival rates. LFSD should be utilized more frequently by minimizing cold ischemia time to <8h, particularly in patients with MELD 3.0 scores below 35. These findings could improve donor-recipient matching and enhance LT outcomes.