The international normalised ratio to monitor coagulation factor production during normothermic machine perfusion of human donor livers

Background: Normothermic machine perfusion (NMP) of donor livers allows for new diagnostic and therapeutic strategies. As the liver produces most of the haemostatic proteins, coagulation assays such as the International Normalised Ratio (INR) performed in perfusate may be useful to assess hepatocellular function of donor livers undergoing NMP. However, high concentrations of heparin and low levels of fibrinogen may affect coagulation assays. Methods: Thirty donor livers that underwent NMP were retrospectively included in this study, of which 18 were subsequently transplanted. We measured INRs in perfusate in presence or absence of exogenously added fibrinogen and/or polybrene. Additionally, we prospectively included 14 donor livers that underwent NMP (of which 11 were transplanted) and measured INR using both a laboratory coagulation analyser and a point-of-care device. Results: In untreated perfusate samples, the INR was above the detection limit in all donor livers. Addition of both fibrinogen and polybrene was required for adequate INR assessment. INRs decreased over time and detectable perfusate INR values were found in 17/18 donor livers at the end of NMP. INR results were similar between the coagulation analyser and the point-of-care device, but did not correlate with established hepatocellular viability criteria. Conclusions: Most of the donor livers that were transplanted showed a detectable perfusate INR at the end of NMP, but samples require processing to allow for INR measurements using laboratory coagulation analysers. Point-of-care devices bypass this need for processing. The INR does not correlate with established viability criteria and might therefore have additional predictive value.</p

The international normalised ratio to monitor coagulation factor production during normothermic machine perfusion of human donor livers

Background: Normothermic machine perfusion (NMP) of donor livers allows for new diagnostic and therapeutic strategies. As the liver produces most of the haemostatic proteins, coagulation assays such as the International Normalised Ratio (INR) performed in perfusate may be useful to assess hepatocellular function of donor livers undergoing NMP. However, high concentrations of heparin and low levels of fibrinogen may affect coagulation assays.Methods: Thirty donor livers that underwent NMP were retrospectively included in this study, of which 18 were subsequently transplanted. We measured INRs in perfusate in presence or absence of exogenously added fibrinogen and/or polybrene. Additionally, we prospectively included 14 donor livers that underwent NMP (of which 11 were transplanted) and measured INR using both a laboratory coagulation analyser and a point-of-care device.Results: In untreated perfusate samples, the INR was above the detection limit in all donor livers. Addition of both fibrinogen and polybrene was required for adequate INR assessment. INRs decreased over time and detectable perfusate INR values were found in 17/18 donor livers at the end of NMP. INR results were similar between the coagulation analyser and the point-of-care device, but did not correlate with established hepatocellular viability criteria.Conclusions: Most of the donor livers that were transplanted showed a detectable perfusate INR at the end of NMP, but samples require processing to allow for INR measurements using laboratory coagulation analysers. Point-of-care devices bypass this need for processing. The INR does not correlate with established viability criteria and might therefore have additional predictive value.</p

The international normalised ratio to monitor coagulation factor production during normothermic machine perfusion of human donor livers

Background: Normothermic machine perfusion (NMP) of donor livers allows for new diagnostic and therapeutic strategies. As the liver produces most of the haemostatic proteins, coagulation assays such as the International Normalised Ratio (INR) performed in perfusate may be useful to assess hepatocellular function of donor livers undergoing NMP. However, high concentrations of heparin and low levels of fibrinogen may affect coagulation assays. Methods: Thirty donor livers that underwent NMP were retrospectively included in this study, of which 18 were subsequently transplanted. We measured INRs in perfusate in presence or absence of exogenously added fibrinogen and/or polybrene. Additionally, we prospectively included 14 donor livers that underwent NMP (of which 11 were transplanted) and measured INR using both a laboratory coagulation analyser and a point-of-care device. Results: In untreated perfusate samples, the INR was above the detection limit in all donor livers. Addition of both fibrinogen and polybrene was required for adequate INR assessment. INRs decreased over time and detectable perfusate INR values were found in 17/18 donor livers at the end of NMP. INR results were similar between the coagulation analyser and the point-of-care device, but did not correlate with established hepatocellular viability criteria. Conclusions: Most of the donor livers that were transplanted showed a detectable perfusate INR at the end of NMP, but samples require processing to allow for INR measurements using laboratory coagulation analysers. Point-of-care devices bypass this need for processing. The INR does not correlate with established viability criteria and might therefore have additional predictive value.</p

Extended hypothermic oxygenated machine perfusion enables ex situ preservation of porcine livers for up to 24 hours

Background & Aims: End-ischemic hypothermic oxygenated machine perfusion (HOPE) of the donor liver for 1-2 h mitigates ischemia-reperfusion injury during subsequent liver transplantation. Extended preservation time may be preferred to facilitate difficult recipient hepatectomy or to optimize logistics. We therefore investigated whether end-ischemic dual HOPE (DHOPE) could extend preservation time for up to 24 h using a porcine liver reperfusion model. Methods: Following 30 min warm ischemia, porcine livers were subjected to 2 h static cold storage (SCS), followed by 2 h, 6 h, or 24 h DHOPE (n = 6 per group). Subsequent normothermic reperfusion was performed for 4 h using autologous blood. Two livers preserved by 24 h SCS served as additional controls. A proof of principle confirmation was carried out in 2 discarded human livers subjected to extended DHOPE. Hepatocellular and cholangiocyte injury and function were assessed. Oxidative stress levels and histology were compared between groups. Results: Perfusion flows remained stable during DHOPE, regardless of duration. After normothermic reperfusion, livers perfused for 24 h by DHOPE had similar lactate clearance, blood pH, glucose, and alanine aminotransferase levels, and biliary pH, bicarbonate, and LDH levels, as livers perfused for 2 h and 6 h. Levels of malondialdehyde and high-mobility group box 1 in serum and liver parenchyma were similar for all groups. Histological analysis of bile ducts and liver parenchyma revealed no differences between the groups. Extended DHOPE in discarded human livers preserved hepatocellular and cholangiocyte function and histology after reperfusion. In contrast, livers preserved by 24 h SCS were non-functioning. Conclusion: Extended end-ischemic DHOPE enabled successful preservation of porcine and discarded human donor livers for up to 24 h. Extended DHOPE enables safe extension of preservation time, which may facilitate allocation and transplantation from a logistical perspective, and further expand the donor pool. Lay summary: It has been suggested that preserving liver grafts with a technique called (dual) hypothermic oxygenated machine perfusion ([D]HOPE) leads to better outcomes after transplantation than if livers are stored on ice, especially if an organ is of lesser quality. In this study, we showed that DHOPE could be used to preserve liver grafts for up to 24 h. This extended procedure could be used globally to facilitate transplantation and expand the donor pool

Restoration of Bile Duct Injury of Donor Livers During Ex Situ Normothermic Machine Perfusion

BACKGROUND: End-ischemic ex situ normothermic machine perfusion (NMP) enables assessment of donor livers prior to transplantation. The objective of this study was to provide support for bile composition as a marker of biliary viability and to investigate whether bile ducts of high-risk human donor livers already undergo repair during NMP.METHODS: Forty-two livers that were initially declined for transplantation were included in our NMP clinical trial. After NMP, livers were either secondary declined (n = 17) or accepted for transplantation (n = 25) based on the chemical composition of bile and perfusate samples. Bile duct biopsies were taken before and after NMP and assessed using an established histological injury severity scoring system and a comprehensive immunohistochemical assessment focusing on peribiliary glands (PBGs), vascular damage, and regeneration.RESULTS: Bile ducts of livers that were transplanted after viability testing during NMP showed better preservation of PBGs, (micro)vasculature, and increased cholangiocyte proliferation, compared with declined livers. Biliary bicarbonate, glucose, and pH were confirmed as accurate biomarkers of bile duct vitality. In addition, we found evidence of PBG-based progenitor cell differentiation toward mature cholangiocytes during NMP.CONCLUSIONS: Favorable bile chemistry during NMP correlates well with better-preserved biliary microvasculature and PBGs, with a preserved capacity for biliary regeneration. During NMP, biliary tree progenitor cells start to differentiate toward mature cholangiocytes, facilitating restoration of the ischemically damaged surface epithelium.</p

Sequential hypothermic and normothermic machine perfusion enables safe transplantation of high-risk donor livers

Ex situ normothermic machine perfusion (NMP) is increasingly used for viability assessment of high-risk donor livers, whereas dual hypothermic oxygenated machine perfusion (DHOPE) reduces ischemia-reperfusion injury. We aimed to resuscitate and test the viability of initially-discarded, high-risk donor livers using sequential DHOPE and NMP with two different oxygen carriers: an artificial hemoglobin-based oxygen carrier (HBOC) or red blood cells (RBC). In a prospective observational cohort study of 54 livers that underwent DHOPE-NMP, the first 18 procedures were performed with a HBOC-based perfusion solution and the subsequent 36 procedures were performed with an RBC-based perfusion solution for the NMP phase. All but one livers were derived from extended criteria donation after circulatory death donors, with a median donor risk index of 2.84 (IQR 2.52–3.11). After functional assessment during NMP, 34 livers (63% utilization), met the viability criteria and were transplanted. One-year graft and patient survival were 94% and 100%, respectively. Post-transplant cholangiopathy occurred in 1 patient (3%). There were no significant differences in utilization rate and post-transplant outcomes between the HBOC and RBC group. Ex situ machine perfusion using sequential DHOPE-NMP for resuscitation and viability assessment of high-risk donor livers results in excellent transplant outcomes, irrespective of the oxygen carrier used.</p

Sequential Hypothermic and Normothermic Machine Perfusion Enables Safe Transplantation of High-risk Donor Livers

Ex situ normothermic machine perfusion (NMP) is increasingly used for viability assessment of high-risk donor livers, whereas dual hypothermic oxygenated machine perfusion (DHOPE) reduces ischemia-reperfusion injury. We aimed to resuscitate and test the viability of initially-discarded, high-risk donor livers using sequential DHOPE and NMP with two different oxygen carriers: an artificial hemoglobin-based oxygen carrier (HBOC) or red blood cells (RBC). In a prospective observational cohort study of 54 livers that underwent DHOPE-NMP, the first 18 procedures were performed with a HBOC-based perfusion solution and the subsequent 36 procedures were performed with an RBC-based perfusion solution for the NMP phase. All but one livers were derived from extended criteria donation after circulatory death donors, with a median donor risk index of 2.84 (IQR 2.52-3.11). After functional assessment during NMP, 34 livers (63% utilization), met the viability criteria and were transplanted. One-year graft and patient survival were 94% and 100%, respectively. Post-transplant cholangiopathy occurred in 1 patient (3%). There were no significant differences in utilization rate and post-transplant outcomes between the HBOC and RBC group. Ex situ machine perfusion using sequential DHOPE-NMP for resuscitation and viability assessment of high-risk donor livers results in excellent transplant outcomes, irrespective of the oxygen carrier used

Sequential hypothermic and normothermic machine perfusion enables safe transplantation of high-risk donor livers

Ex situ normothermic machine perfusion (NMP) is increasingly used for viability assessment of high-risk donor livers, whereas dual hypothermic oxygenated machine perfusion (DHOPE) reduces ischemia-reperfusion injury. We aimed to resuscitate and test the viability of initially-discarded, high-risk donor livers using sequential DHOPE and NMP with two different oxygen carriers: an artificial hemoglobin-based oxygen carrier (HBOC) or red blood cells (RBC). In a prospective observational cohort study of 54 livers that underwent DHOPE-NMP, the first 18 procedures were performed with a HBOC-based perfusion solution and the subsequent 36 procedures were performed with an RBC-based perfusion solution for the NMP phase. All but one livers were derived from extended criteria donation after circulatory death donors, with a median donor risk index of 2.84 (IQR 2.52–3.11). After functional assessment during NMP, 34 livers (63% utilization), met the viability criteria and were transplanted. One-year graft and patient survival were 94% and 100%, respectively. Post-transplant cholangiopathy occurred in 1 patient (3%). There were no significant differences in utilization rate and post-transplant outcomes between the HBOC and RBC group. Ex situ machine perfusion using sequential DHOPE-NMP for resuscitation and viability assessment of high-risk donor livers results in excellent transplant outcomes, irrespective of the oxygen carrier used.</p