title: Hypothermic machine perfusion of the liver and the critical balance between perfusion pressures and endothelial injury.
abstract: Hypothermic machine perfusion (HMP) provides better protection against cold ischemic injury than cold storage in marginal donor kidneys. Also, in liver transplantation a switch from static cold storage to HMP could be beneficial as it would allow longer preservation times and the use of marginal donors. A critical question concerning application of HMP in liver preservation is the crucial balance between perfusion pressure and occurrence of endothelial injury. Rat livers were cold-perfused for 24 hours to study perfusion pressures for both hepatic artery and portal vein. Cold storage served as control and was compared to HMP-preserved livers using a mean arterial perfusion pressure of 25 mm Hg and a portal perfusion pressure of 4 mm Hg (25% of normothermic liver circulation) and to HMP at 50 mm Hg and 8 mm Hg perfusion, respectively (50% of normothermic liver circulation). UW solution was enriched with 14.9 micromol/L propidium iodide (PI) to stain for dead cells and with an additional 13.5 micromol/L acridine orange to stain for viable hepatocytes. A low PI-positive cell count was found using HMP at 25% of normal circulation compared to cold storage. The PI count was high for the HMP group perfused at just 50% of normal circulation compared to HMP at 25% and compared to cold storage. In summary, for liver HMP, perfusion at 25% showed complete perfusion with minimal cellular injury. HMP using perfusion pressures of 25 mm Hg for the hepatic artery and 4 mm Hg for the portal vein is feasible without induction of endothelial injury.
authors.affiliation: Surgery Research Laboratory, University Hospital Groningen, Groningen, The Netherlands.
authors.forename: N A
authors.initials: NA
authors.lastname: 't Hart
authors.forename: A
authors.initials: A
authors.lastname: van der Plaats
authors.forename: H G D
authors.initials: HG
authors.lastname: Leuvenink
authors.forename: H
authors.initials: H
authors.lastname: van Goor
authors.forename: J
authors.initials: J
authors.lastname: Wiersema-Buist
authors.forename: G J
authors.initials: GJ
authors.lastname: Verkerke
authors.forename: G
authors.initials: G
authors.lastname: Rakhorst
authors.forename: R J
authors.initials: RJ
authors.lastname: Ploeg
mesh_terms: D000818:Animals; D004727:Endothelium / Q000473:pathology*; D006499:Hepatic Artery; D007036:Hypothermia, Induced; D008099:Liver / Q000166:cytology / Q000473:pathology / Q000502:physiology; D008856:Microscopy, Fluorescence; D023421:Models, Animal; D009926:Organ Preservation / Q000379:methods*; D051381:Rats; D011919:Rats, Inbred Strains