title: Intrahepatic left to right portoportal venous collateral vascular formation in patients undergoing right portal vein ligation.
abstract: OBJECTIVE
  We investigated intrahepatic vascular changes in patients undergoing right portal vein ligation (PVL) or portal vein embolization (PVE) in conjunction with the ensuing hypertrophic response and function of the left liver lobe.
  
  
  METHODS
  Between December 2008 and October 2011, 7 patients underwent right PVL and 14 patients PVE. Computed tomographic (CT) volumetry to assess future remnant liver (FRL) and functional hepatobiliary scintigraphy were performed in all patients before and 3 weeks after portal vein occlusion. In 18 patients an intraoperative portography was performed to assess perfusion through the occluded portal branches.
  
  
  RESULTS
  In all patients after initially successful PVL, reperfused portal veins were observed on CT scan 3 weeks after portal occlusion. This was confirmed in all cases during intraoperative portography. Intrahepatic portoportal collaterals were identified in all patients in the PVL group and in one patient in the PVE group. In all other PVE patients, complete occlusion of the embolized portal branches was observed on CT scan and on intraoperative portography. The median increase of FRL volume after PVE was 41.6 % (range 10-305 %), and after PVL was only 8.1 % (range 0-102 %) (p = 0.179). There were no differences in FRL function between both groups.
  
  
  CONCLUSIONS
  Preoperative PVE and PVL are both methods to induce hypertrophy of the FRL in anticipation of major liver resection. Compared to PVE, PVL seems less efficient in inducing hypertrophy of the nonoccluded left lobe. This could be caused by the formation of intrahepatic portoportal neocollateral vessels, through which the ligated portal branches are reperfused within 3 weeks.
authors.affiliation: Department of Interventional Radiology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands. k.p.vanlienden@amc.uva.nl.
authors.forename: K P
authors.initials: KP
authors.lastname: van Lienden
authors.affiliation: Department of Surgery, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
authors.forename: L T
authors.initials: LT
authors.lastname: Hoekstra
authors.affiliation: Department of Nuclear Medicine, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
authors.forename: R J
authors.initials: RJ
authors.lastname: Bennink
authors.affiliation: Department of Surgery, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
authors.forename: T M
authors.initials: TM
authors.lastname: van Gulik
mesh_terms: D003097:Collateral Circulation / Q000502:physiology*; D054893:Cone-Beam Computed Tomography / Q000379:methods; D004621:Embolization, Therapeutic / Q000379:methods; D005260:Female; D006529:Hepatomegaly / Q000209:etiology / Q000503:physiopathology*; D006801:Humans; D006984:Hypertrophy / Q000000981:diagnostic imaging / Q000503:physiopathology; D008026:Ligation; D008099:Liver / Q000098:blood supply / Q000000981:diagnostic imaging; D008102:Liver Circulation / Q000502:physiology*; D008111:Liver Function Tests / Q000379:methods; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D011169:Portal Vein / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011172:Portography / Q000379:methods; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D016896:Treatment Outcome