title: Energetic recovery in porcine grafts by minimally invasive liver oxygenation.
abstract: BACKGROUND
  Gaseous insufflation of oxygen via the venous vascular system has proven to be an effective tool for preventing anoxic tissue injury after extended time periods of ischemic liver preservation. Most experimental studies so far have been undertaken in rat models and include a series of pinpricks into postsinusoidal venules as an outlet for the insufflated gas. Here, we describe a simplified technique for minimally invasive liver oxygenation in porcine grafts, representing a hassle-free access to organ oxygenation without vascular lesions.
  
  
  METHODS
  We retrieved livers from Landrace pigs and cold-stored them in histidine-tryptophan-ketoglutarate solution. Subsequent to 18 h preservation, we treated some livers for an additional 2 h with gaseous oxygen, insufflated via silicone tubing inserted into the suprahepatic caval vein. Gas pressure was limited to 18 mm Hg. We occluded the infrahepatic caval vein with a bulldog clamp. Gas bubbles left the graft via the portal vein. We assessed liver integrity by energetic tissue status and by controlled in vitro reperfusion with autologous blood.
  
  
  RESULTS
  Magnetic resonance imaging demonstrated homogeneous gas distribution in the persufflated tissue without major shunting. Biochemical analyses revealed effective and homogeneous restoration of energetic homeostasis in the ischemic graft before reperfusion. Sinusoidal endothelial clearance of hyaluronic acid was significantly improved upon reperfusion, as was hepatic arterial flow. Parenchymal enzyme loss was concordantly mitigated after minimally invasive liver oxygenation.
  
  
  CONCLUSIONS
  Our results indicate that gaseous oxygen persufflation of the porcine liver is possible without tissue trauma, and significantly enhances post-preservation recovery of the graft.
authors.affiliation: Surgical Research Division, University of Bonn, 53127 Bonn, Germany. minor@uni-bonn.de
authors.forename: Thomas
authors.initials: T
authors.lastname: Minor
authors.forename: William E
authors.initials: WE
authors.lastname: Scott
authors.forename: Michael D
authors.initials: MD
authors.lastname: Rizzari
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Suszynski
authors.forename: Bastian
authors.initials: B
authors.lastname: Luer
authors.forename: Patrik
authors.initials: P
authors.lastname: Efferz
authors.forename: Klearchos K
authors.initials: KK
authors.lastname: Papas
authors.forename: Andreas
authors.initials: A
authors.lastname: Paul
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D004734:Energy Metabolism; D008099:Liver / Q000098:blood supply*; D016031:Liver Transplantation; D015424:Reperfusion; D013552:Swine
chemical_list: D000255:Adenosine Triphosphate