HOPE for Human Extended Criteria and Donation After Brain Death Donor (ECD-DBD) Liver Allografts

Overview

The purpose of this study is to test the effects of hypothermic oxygenated machine perfusion (HOPE) in a phase-II prospective multicenter randomized clinical trial (RCT) on extended criteria donor allografts (ECD) in donation after brain death (DBD) orthotropic liver-transplantation (OLT) (HOPE-ECD-DBD). Human whole organ liver grafts will be submitted to 1-2 hours of HOPE via the portal vein directly before implantation and going to be compared to a control-group of patients transplanted after conventional cold storage (CCS). Primary (early graft injury) and secondary (e.g. postoperative complications, hospital stay, survival) objectives are going to be analysed in a 12 month follow up. Ischemia-reperfusion (I/R) injury and inflammation will be assessed using liver tissue, serum and bile samples as well as machine perfusion perfusate. To improve the availability of donor allografts and reduce waiting list mortality, graft acceptance criteria were extended increasingly over the decades. The use of extended criteria donor (ECD) allografts is associated with higher incidences of primary graft non-function (PNF) and/or delayed graft function (DGF). As such, several strategies have been developed aiming at "reconditioning" poor quality ECD grafts. HOPE has been tested intensively in pre-clinical animal experiments. Although, its known that HOPE can exert its reconditioning effect via cellular and mitochondrial pathways in the endothelial and parenchymal cells, there is still scarce evidence available on the exact subcellular mechanism of HOPE induced organ protection in the clinical scenario of liver transplantation. In donation after cardiac death (DCD) OLT, the positive effects of HOPE have been shown to reduce the incidence of biliary complications, mitochondrial damage and improve the overall cellular energy-status. In the HOPE setting, organ perfusion is performed in the transplant center shortly before the actual implantation with oxygenated perfusate using an extra corporal organ perfusion system. The first clinical study with this promising technique was recently reported in a Swiss cohort of patients who received DCD allografts. In organ donation after brain death (DBD), the only legally accepted approach for organ donation in most countries, HOPE and its effect on early graft injury and postoperative complications remains to be elucidated.

The present RCT comprises two groups, a perfusion (group 1; HOPE) and a control conventional cold storage (group 2; CCS) group. Patients with proven written informed consent on waiting list for orthotopic liver transplantation will be recruited. Randomization is performed with an online randomizing tool for clinical trials (www.randomizer.at) at the time of allograft arrival at the transplant center and acceptance of the organ for transplantation. Stratified randomization model will be used to ensure balance of prognostic variables between the treatment groups. In case of randomisation to group 1, HOPE will be applied to the allograft in the operation room, directly after the back table preparation. The application of HOPE to the liver allograft will not delay the implantation due to the fact that it is performed parallel to the recipient hepatectomy. Commercially available and machine-perfusion approved Belzer MPS® UW solution (Belzer Organ Preservation Solutions, Bridge for Life) will be used as perfusate for machine perfusion. Patients will be followed for one year after OLT. Interim analysis: After n=12 per randomized group is reached, data will be analyzed by an independent Data Monitoring Committee. The RCT will be stopped if one of the following criteria is reached: Significantly higher serum ALT levels (p\<0.001 using Student's t-test) in the HOPE group compared to the CCS group (Efficacy). The proportion of Grade ≥ III complications is significantly higher (p\<0.05, Fischer's exact test) in the HOPE group when compared to the CCS group (Safety).