Quantifying the Disadvantage of Small Recipient Size on the Liver Transplantation Waitlist, a Longitudinal Analysis Within the Eurotransplant Region

Background. Small adult patients with end-stage liver disease waitlisted for liver transplantation may face a shortage of size-matched liver grafts. This may result in longer waiting times, increased waitlist removal, and waitlist mortality. This study aims to assess access to transplantation in transplant candidates with below-average bodyweight throughout the Eurotransplant region. Methods. Patients above 16 y of age listed for liver transplantation between 2010 and 2015 within the Eurotransplant region were eligible for inclusion. The effect of bodyweight on chances of receiving a liver graft was studied in a Cox model corrected for lab-Model for End-stage Liver Disease (MELD) score updates fitted as time-dependent variable, blood type, listing for malignant disease, and age. A natural spline with 3 degrees of freedom was used for bodyweight and lab-MELD score to correct for nonlinear effects. Results. At the end of follow-up, the percentage of transplanted, delisted, and deceased waitlisted patients was 49.1%, 17.9%, and 24.3% for patients with a bodyweight <60 kg (n = 1267) versus 60.1%, 15.1%, and 18.6% for patients with a bodyweight ≥60 kg (n = 10 520). To reach comparable chances for transplantation, 60-kg and 50-kg transplant candidates are estimated to need, respectively, up to 2.8 and 4.0 more lab-MELD points than 80-kg transplant candidates. Conclusions. Decreasing bodyweight was significantly associated with decreased chances to receive a liver graft. This resulted in substantially longer waiting times, higher delisting rates, and higher waitlist mortality for patients with a bodyweight <60 kg.