Normothermic Machine Perfusion and Liver Transplant Waitlist Times: A Single-Center Matched Cohort Study

Abstract

Introduction: Normothermic machine perfusion (NMP) is a promising technology for expanding the donor liver pool. This study aims to evaluate the association between the implementation of NMP on liver transplant waitlist times at a single center.

Methods: We conducted a retrospective cohort study of patients who underwent liver transplant at Beth Israel Deaconess Medical Center from 2014 to 2024. Waitlist times were compared between pre-NMP and post-NMP implementation periods. Matched cohorts based on sex, age, and the model for end-stage liver disease score were used to compare patients who received machine-perfused livers (NMP group) and those who did not (non-NMP group). Waitlist duration, donor type, hospital stay, overall survival, and graft failure were measured. A subgroup of patients diagnosed with hepatocellular carcinoma (HCC) was analyzed.

Results: Of 429 patients, median waitlist times were significantly reduced from 309 d pre-NMP to 48 d post-NMP (P < 0.001). In the matched analysis, the NMP group had a median waitlist time of 71 d, compared to 345 d for non-NMP group (P < 0.001). The NMP group had a 2-d shorter hospital stay than the non-NMP group (P < 0.001). For HCC patients, waitlist times decreased from 472 d pre-NMP to 83 d post-NMP (P < 0.001), and in the matched HCC cohorts, waitlist times decreased from 492 d to 121 d in the non-NMP and NMP groups, respectively (P < 0.001).

Conclusions: NMP implementation was associated with significantly shorter liver transplant waitlist times and reduced hospital stays, without compromising short-term survival outcomes. NMP may address the liver transplant shortage and improve access for patients, particularly those with HCC.

Keywords: Extended-criteria organ; Hepatocellular carcinoma; Liver transplantation; Matched cohort; Normothermic machine perfusion; Transplantation; Waitlist times.