Establishing a Normothermic Machine Perfusion Program for Liver Transplantation: Lessons Learned and Early Outcomes in the United States

Abstract

Background: Normothermic machine perfusion (NMP) has emerged as a promising technology in liver transplantation, but limited data exist regarding real-world implementation in the United States following FDA approval. We report our experience establishing an NMP program and share insights from our first 100 cases.

Methods: We retrospectively analyzed 100 consecutive liver NMP cases performed between July 2023 and May 2024 using the OrganOx Metra device. Program establishment required assembling a dedicated team, comprehensive training, establishing a dedicated perfusion facility, coordinating with multiple departments including laboratory, blood bank, electronic medical record vendors, and billing services, and developing institutional viability criteria.

Results: Of 100 NMP cases, 92 proceeded to transplantation while eight were declined. Early allograft dysfunction occurred in 19 cases (20.7%) with no instances of primary non-function, and 90-day graft survival was 94.6%. No graft losses were directly attributable to NMP. Six grafts showed delayed lactate clearance but achieved successful outcomes with extended perfusion time. We systematically refined our protocols and developed standardized troubleshooting approaches to address various technical challenges including graft bleeding, arterial flow monitoring issues, persistent acidosis, and bile duct drainage issues.

Conclusions: Successful implementation of an NMP program requires careful preparation, dedicated staffing, and interdepartmental coordination. Although various challenges are expected in the initial phase of the program, these can be successfully managed with a systematic approach. Our experience provides practical guidance for centers planning to establish NMP programs.

Keywords: donors and donation: deceased; liver allograft function/dysfunction; organ perfusion and preservation.

FIGURE 1

(A) Dedicated NMP room equipped with a reliable power supply, computer, and other essential tools. (B) Standardized NMP medication package. (C) Cannulation technique for replaced/accessory left hepatic artery. The diagram illustrates cannulation performed through the splenic artery following oversewing of the celiac trunk rather than ligation. (D) Cannulation technique for replaced/accessory right hepatic artery. An end‐to‐end anastomosis was performed between the superior mesenteric artery and celiac trunk. The diagram illustrates cannulation performed through splenic artery. CHA indicates common hepatic artery; LHA, left hepatic artery; NMP, normothermic machine perfusion; RHA, Right hepatic artery; SMA, Superior mesenteric artery.

FIGURE 2

Indications for normothermic machine perfusion in 100 cases. Venn diagram illustrates the primary indications for NMP in our cohort, categorized into graft quality, recipient complexity, and logistical considerations.

FIGURE 3

Organ viability criteria during normothermic machine perfusion at Virginia Commonwealth University Hume‐ Lee Transplant Center. Organ acceptance decisions are guided by a comprehensive assessment of specific viability parameters during normothermic machine perfusion. Parameters are stratified into three categories: optimal (green), suboptimal but potentially acceptable (yellow), and unacceptable (red). Organs meeting all optimal criteria are deemed suitable for transplantation. If any parameter falls within the suboptimal range, acceptance decisions are based on an integrated evaluation of donor characteristics, recipient factors, and perfusion metrics. Presence of any unacceptable parameter results in organ decline. ALT indicates alanine aminotransferase.