title: Improved microcirculation of a liver graft by controlled portal vein arterialization.
abstract: BACKGROUND
  The clinical results of portal vein arterialization (PVA) in liver transplantation are controversial without a standardized portal flow regulation. The aim of these experiments was to perform a flow-regulated PVA in liver transplantation, to examine the microcirculation and early graft function after heterotopic auxiliary liver transplantation (HALT) with flow-regulated PVA, and to compare this technique with HALT with porto-portal anastomosis. Using the recently developed orthogonal polarization spectral (OPS) imaging, for the first time the microcirculation of liver grafts with PVA was visualized.
  
  
  METHODS
  HALT was performed in Lewis rats. The portal vein was either completely arterialized via the right renal artery in a standardized splint-technique (Group I, n = 8) or anastomosed end-to-end to the recipient's portal vein (Group II, n = 8).
  
  
  RESULTS
  After reperfusion, the average blood flow in the portal vein was within the normal range in Group I (1.7 +/- 0.4 ml/min/g liver weight) and significantly higher than in Group II (1.2 +/- 0.2 ml/min/g liver weight). The functional sinusoidal density in Group I (335 +/- 48/microm) was significantly higher than in Group II (232 +/- 58/microm), whereas the diameter of the sinusoids and the postsinusoidal venules yielded no significant differences between both groups. The bile production was comparable (27 +/- 8 versus 29 +/- 11 microl/h/g liver weight).
  
  
  CONCLUSIONS
  In our experiments it was possible to achieve an adequate flow regulation in the arterialized portal vein with good results concerning microcirculation and early graft function. We recommend that further investigations on liver transplantation with PVA should be performed with portal flow regulation, before PVA is employed in clinical transplantation.
authors.affiliation: Department of Visceral and Vascular Surgery, University of Cologne, Joseph-Stelzmann-Strasse 9, 50931, Cologne, Germany. Karina.Schleimer@medizin.uni-koeln.de
authors.forename: Karina
authors.initials: K
authors.lastname: Schleimer
authors.forename: Dirk L
authors.initials: DL
authors.lastname: Stippel
authors.forename: Hans U
authors.initials: HU
authors.lastname: Kasper
authors.forename: Christian
authors.initials: C
authors.lastname: Suer
authors.forename: Samir
authors.initials: S
authors.lastname: Tawadros
authors.forename: Arnulf H
authors.initials: AH
authors.lastname: Hoelscher
authors.forename: K Tobias E
authors.initials: KT
authors.lastname: Beckurts
mesh_terms: D000818:Animals; D001166:Arteriovenous Shunt, Surgical; D001646:Bile / Q000378:metabolism; D006499:Hepatic Artery / Q000503:physiopathology / Q000601:surgery*; D008099:Liver / Q000473:pathology / Q000503:physiopathology; D008102:Liver Circulation; D016031:Liver Transplantation / Q000379:methods*; D008297:Male; D008833:Microcirculation; D008859:Microscopy, Polarization; D011169:Portal Vein / Q000503:physiopathology / Q000601:surgery*; D051381:Rats; D011917:Rats, Inbred Lew; D012039:Regional Blood Flow; D015424:Reperfusion