title: In vivo assessment of the hepatic microcirculation after mesenterico-portal bypass (REX-shunt) using orthogonal polarization spectral imaging.
abstract: BACKGROUND
  Extrahepatic portal vein thrombosis, not associated with cirrhosis or tumours, is the second most frequent cause of portal hypertension worldwide. Especially in children, anatomic mesenterico-portal interposition (REX-shunt) has become an established treatment. The changes in hepatic microcirculation after reperfusion of the shunt have not been investigated so far.
  
  
  OBJECTIVE
  This study investigates the hepatic microcirculation before and after REX-shunt interposition using orthogonal polarization spectral imaging (OPS).
  
  
  METHODS
  Since 2004, three consecutive patients with extrahepatic portal vein thrombosis underwent REX-shunt interposition. We measured the hepatic microcirculation by OPS before and directly after REX-shunt reperfusion and analysed the capillary vessel diameter, red blood cell velocity, functional capillary density and volumetric blood flow. Furthermore, we compared our values with the physiological values of the hepatic microcirculation defined previously by other investigators.
  
  
  RESULTS
  All shunts showed an excellent function in the follow-up investigations. The intra-individual microcirculatory analysis revealed a reduction in the red blood cell velocity after shunt reperfusion in particular.
  
  
  CONCLUSIONS
  Our results provide preliminary evidence for the reversal of the hepatic arterial buffer response following the restoration of the portal venous blood flow. This may be a short-term effect because of the restored portal venous blood flow.
authors.affiliation: Department of General, Visceral and Vascular Surgery, Friedrich-Schiller-University Jena, Jena, Germany. falk.rauchfuss@med.uni-jena.de
authors.forename: Falk
authors.initials: F
authors.lastname: Rauchfuss
authors.forename: Hubert
authors.initials: H
authors.lastname: Scheuerlein
authors.forename: Stefan
authors.initials: S
authors.lastname: Ludewig
authors.forename: Torsten
authors.initials: T
authors.lastname: Uberrück
authors.forename: Michael
authors.initials: M
authors.lastname: Heise
authors.forename: Jürgen
authors.initials: J
authors.lastname: Zanow
authors.forename: Utz
authors.initials: U
authors.lastname: Settmacher
mesh_terms: D000328:Adult; D002196:Capillaries / Q000473:pathology; D002648:Child; D006801:Humans; D006975:Hypertension, Portal / Q000209:etiology / Q000473:pathology / Q000601:surgery; D008099:Liver / Q000098:blood supply* / Q000473:pathology; D008833:Microcirculation; D008859:Microscopy, Polarization / Q000379:methods*; D011169:Portal Vein / Q000473:pathology / Q000601:surgery; D011170:Portasystemic Shunt, Surgical; D011183:Postoperative Complications; D013927:Thrombosis / Q000150:complications / Q000473:pathology / Q000601:surgery; D055815:Young Adult