Navigating new frontiers: onsite machine perfusion in US liver transplantation

Area of Science:

• Hepatology
• Transplantation Surgery
• Organ Preservation

Background:

• Increasing demand for liver transplantation (LT) necessitates the use of marginal donors.
• Onsite machine perfusion (OMP) may enable the use of previously non-utilized organs.
• Limited data exists on OMP's safety and efficacy in LT using national databases.

Purpose of the Study:

• To assess the utilization and implications of OMP in liver transplantation.
• To evaluate the impact of marginal donor quality, using the donor organ discard index (DSRI), on recipient outcomes with OMP.
• To analyze trends in OMP usage in the US national database.

Main Methods:

• Utilized the UNOS database from 2016-2023, identifying 50,458 LT cases.
• Examined OMP usage patterns and trends, noting a surge since 2022.
• Compared outcomes (graft survival, hazard ratios) between OMP and non-OMP groups, stratifying by donor type and characteristics.

Main Results:

• OMP was used in 2.5% of LT cases, with usage exceeding 10% by early 2023.
• OMP livers had higher DSRI in donation after brain death (DBD) but comparable graft survival.
• OMP livers from donation after cardiac death (DCD) donors showed improved 90-day/1-year graft survival despite higher DSRI.
• OMP use in high DSRI DCD donors correlated with lower hazard ratios.
• No graft failures were reported in OMP cases with macrosteatosis ≥30%.

Conclusions:

• OMP usage in LT has significantly increased post-commercialization.
• OMP offers comparable outcomes to non-OMP, even with higher DSRI, optimizing marginal donor utilization.
• OMP shows potential to expand the donor pool for liver transplantation.