Outcomes after Ex-vivo Liver Splitting during Hypothermic Oxygenated Perfusion - A Prospective Case Series

Abstract

Introduction: Ex-vivo liver graft splitting in donation after brain death increases cold ischemia leading to inferior outcomes compared to whole grafts. Hypothermic Oxygenated Perfusion (HOPE) improves outcomes of marginal liver grafts and may also benefit split grafts. We present outcomes from the first case series of ex-vivo liver graft splitting during HOPE with subsequent transplantation. Method: In 2020, we developed HOPE-Split, an ex-vivo liver splitting technique with concurrent HOPE. We included all conventional ex-vivo liver splits performed from 2018-2020 at our center as comparison cohort. Results: During the study period, we performed 6 HOPE-Split procedures resulting in 12 successful liver transplantations in 6 pediatric and 6 adult recipients. During HOPE, both partial grafts were perfused for a mean 125min through a single portal cannula until respective recipient hepatectomies were completed. In comparison to the standard ex-vivo split, HOPE-Split grafts displayed significantly shorter static cold storage times (542min vs 470min, p =0,02) but comparable total ex-vivo preservation (543min vs 600min). Despite a higher donor risk in the HOPE-Split cohort (Donor Risk Index 1,9 vs 2,16, p=0,29), factor V normalization in the recipients was comparable to standard splits. No primary non function nor early vascular complications occurred and all 12 recipients present normal liver values after a mean follow-up of 4 months. Conclusions: Our preliminary results confirm feasibility of HOPE-Split and suggest improved preservation with reduced static cold storage in high-risk split grafts. Pending validation in a larger cohort, HOPE-Split may allow to improve outcomes and increase the use of split grafts.