View clinical trials related to Hepatocellular Injury.
Filter by:The common practice of conventional cold storage (CCS) organ preservation has changed little since the initial introduction of the original University of Wisconsin (UW) organ preservation solution in the late 1980s. CCS relies on hypothermia to decelerate metabolism and reduce oxygen demand in order to prolong the time of ischemia without rapid functional graft impairment, therefore merely delaying graft damage. While CCS only prolongs storage time and limits the damage sustained during the period of cold ischemia, ex-vivo machine perfusion (MP) appears to be capable of reversing some of these effects. Currently, two main paradigms prevail in the clinical approach to liver allograft MP: hypothermic oxygenated MP (HOPE) may be seen as a dynamic alternative of the traditional organ preservation based on hypothermia-induced deceleration of metabolism, which aims to combine the positive effects of hypothermia observed in classical cold storage (e.g. technical simplicity, relative safety, decreased metabolism) with the positive effects of dynamic preservation (e.g. controlled sheer stress mediated gene activation, removal of metabolites, transport of oxygen and ATP recharging). Normothermic perfusion (NMP) aims at re-equilibration of cellular metabolism by preserving the organ at physiological temperatures whilst ensuring sufficient oxygen and nutrient supply. In both approaches, the perpetual circulation and moderate shear-stress sustain endothelial functionality. While past and current clinical trials were designed to compare different MP approaches with CCS as the clinical standard, a direct comparison between different end-ischemic MP techniques (HOPE versus NMP) is still lacking. The purpose of this study is to test the effects of end-ischemic NMP versus end-ischemic HOPE technique in a multicentre prospective randomized controlled clinical trial (RCT) on ECD liver grafts in DBD liver-transplantation (HOPE-NMP). Two-hundred-thirteen (n = 213) human whole organ liver grafts will be submitted to either 4-24 hours of NMP (n = 85) or 2-3 hours of HOPE (n = 85) directly before implantation and going to be compared to a control-group of patients (n = 43) transplanted with static cold storage preserved ECD-allografts. Primary (surgical complications as assessed by the comprehensive complication index [CCI]) and secondary (among others laboratory values, graft- and patient survival, hospital costs, hospital stay) endpoints are going to be analysed.)
Interest of oxygenated hypothermic perfusion in preservation of hepatic grafts from expanded criteria donors.
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 purpose of this study is, in a randomized trial, to test a newly developed machine perfusion technique of human liver allografts before transplantation. Ischemia-reperfusion injury is universal in organ transplantation and leads to varying degrees of graft dysfunction. Despite this fact, the preservation method in organ transplantation has been left unchanged for many years and remains simple static cold storage. Given the scarce donor supply, an increasing number of so called marginal or extended criteria donor organs have been used for liver transplantation, grafts which were previously rarely considered. In addition, allocation policy has changed in many countries, and livers are currently often distributed by the severity of the recipient's disease. As a result, transplant candidates present sicker, with higher MELD (Model for end stage liver disease) scores, at the time of transplant,and the risk of graft dysfunction or even failure due to reperfusion injury is high after the use of marginal livers in sick recipients. Machine liver perfusion techniques have been significantly improved during the past decade to decrease reperfusion injury, and a number of promising results show beneficial effects in various animal transplant models by either normothermic or hypothermic oxygenated continuous liver perfusion. These techniques generally require machine liver perfusion immediately after organ procurement. However, continuous perfusion has several drawbacks, including major logistic efforts and risk of organ damage during perfusion and transport. Our group, therefore, focused on the practicability of machine liver perfusion. We developed an endischemic hypothermic oxygenated perfusion (HOPE) concept through the portal vein only. This technique can be easily applied in the operation room shortly before transplantation of the recipient, thus after organ transport and back table preparation. Recently, the beneficial effect of a similar approach has been confirmed in human liver grafts by a phase I non randomized trial. These results prove feasibility and safety of an endischemic hypothermic machine perfusion approach and warrant further randomized studies.
In order to prevent excessive blood loss during liver surgery, an intermittent Pringle manoeuvre (IPM) can be applied. This implies a temporary clamping of the portal vein and hepatic artery in the hepatoduodenal ligament in order to occlude hepatic inflow. The optimal duration of the IPM is unknown. This randomized controlled trial aimed to analyse differences in hepatocellular damage after 15 minutes or 30 minutes IPM during liver surgery for primary or secondary liver tumours.