Transplantation of rejected high risk liver allografts following normothermic ex-situ evaluation

The demand for liver transplantation exceeds supply with rising waiting list mortality. Utilisation of high-risk organs is low and a substantial number of procured livers are discarded. We report the first series of five transplants with rejected livers following viability assessment by normothermic machine perfusion of the liver (NMP-L). The evaluation protocol consisted of perfusate lactate, bile production, vascular flows and liver appearance. All livers were exposed to a variable period of static cold storage prior to commencing NMP-L. Four organs were recovered from donors after circulatory death and rejected due to prolonged donor warm ischaemic times; one liver from a brain death donor was declined for high liver function tests. The median (range) total graft preservation time was 798 (724-951) minutes. The transplant procedure was uneventful in every recipient with immediate function in all grafts. The median in-hospital stay was 10 (6-14) days. At present, all recipients are well, with normalised liver function tests at median follow-up of 7 (6-19) months. Viability assessment of high-risk grafts using NMP-L provides specific information on liver function and can permit their transplantation while minimising the recipient risk of primary graft non-function. This novel approach may increase organ availability for liver transplantation.