Normothermic Machine Preservation of Marginal Livers in Australasia - Initial Brisbane Experience Using a “Back-to-Base” Approach

Abstract

Introduction: The assessment of marginal liver suitability using empirical criteria remains imprecise. Ex-vivo normothermic machine perfusion (NMP) allows for a period of graft assessment under near-physiological conditions, which might improve the selection of such livers for transplantation. We describe the first 11 clinical applications of NMP in Australasia using a “back-to-base” approach. Methods: Eleven marginal livers were accepted for preservation and assessment on the OrganOx metra device following a period of static cold storage (post-SCS-NMP). Average donor risk index was 1.53 (1.08-1.93), with five grafts donated after brain death (DBD) and six donated after circulatory death (DCD). All DCD grafts were outside of established local criteria. Average cold ischaemic time and NMP time was 5.2 (4.2-6.5) hours and 12.0 (9.1-17.6) hours respectively. Recipient MELD score was 17 (11-20), including one combined liver-kidney transplant and one re-transplant. Results: All livers met pre-established viability criteria and were successfully transplanted. Five (45%) recipients developed early allograft dysfunction based solely on peak AST >2000 U/L (average 1860 (629-8910) U/L, Figure 1). Two patients (18%) required revisional surgery for biliary anastomotic complications following initial Roux-en-Y hepaticojejunostomy. No clinically significant biliary problems were observed in the nine patients receiving duct-to-duct anastomosis. All cases have satisfactory graft function to date. Conclusions: Post-SCS NMP was successfully implemented in 11 cases, enabling the safe utilisation of grafts deemed non-transplantable using static cold storage preservation alone. The technique was user friendly, improved transplant logistics and surgeon confidence, and increased local transplant activity by 10%.