Changing Landscape of Open Offers in Liver Transplantation in the Machine Perfusion Era: Exposure, Equity, and Economics.

Background: Open offers (OOs) in liver transplantation (LT) result from bypassing the traditional allocation system. Little is known about the trends of OOs or the differences in donor/recipient characteristics compared to traditionally placed organs. We aim to quantify modern practices regarding OOs and understand NMP's impact, focusing on social determinants of health (SDH), cost, and graft-associated risk.

Methods: LTs from 1/1/2018 to 12/31/2023 at a single center were included. NMP was implemented on 10/1/2022. The CDC (centers for disease control)-validated social vulnerability index (SVI) and donor risk index (DRI) were calculated. Comprehensive complications index (CCI), Clavien-Dindo grades, patient and graft survival, and costs of transplantation were included.

Results: 1162 LTs were performed; 193 (16.8%) from OOs. OOs were more common in the post-NMP era (26.5% vs. 13.3%, p < 0.001). Pre-NMP, patients receiving OOs had longer waitlist times (118 vs. 69 days, p < 0.001), lower MELDs (17 vs. 25 points, p < 0.001), and riskier grafts (DRI = 1.8 vs. 1.6, p = 0.004) compared to standard offers. Post-NMP, recipients receiving OOs demonstrated no difference in waitlist time (27 vs. 20 days, p = 0.21) or graft risk (DRI = 2.03 vs. 2.23, p = 0.17). OO recipient MELD remained lower (16 vs. 22, p < 0.001). OO recipients were more socially vulnerable (SVI), pre-NMP (0.41 vs. 0.36, p = 0.004), but less vulnerable after NMP (0.23 vs. 0.36, p = 0.019). Despite increased graft risk, pre-NMP OO-LTs were less expensive in the 90-day global period ($154 939 vs. $178 970, p = 0.002) and the 180-days pre-/post-LT ($208 807 vs. $228 091, p = 0.021). Cost trends remained similar with NMP.

Conclusion: OOs are increasingly utilized and may be appealing due to demonstrated cost reductions even with NMP. Although most OO-related metrics in our center remain similar before and after machine perfusion, programs should take caution that increasing use does not worsen organ access for socially vulnerable populations.