title: Imaging the Rex vein preoperatively using wedged hepatic venous portography.
abstract: BACKGROUND
  Mesentericoportal bypass, the Rex shunt, restores the physiological hepatic portal flow and reduces the clinical sequelae of portal hypertension in children with extrahepatic portal vein obstruction (EHPVO). The preoperative evaluation includes an accurate assessment of the portal venous inflow and outflow. The former is readily assessed by ultrasound and MRI, while the outflow intrahepatic portal vein is harder to assess.
  
  
  OBJECTIVE
  To assess the efficacy of wedged hepatic venous portography (WHVP) at detecting a patent Rex vein preoperatively in children with EHPVO who were considered for mesenterico-portal bypass.
  
  
  METHODS
  A single-institution retrospective chart review was undertaken for children with EHPVO who had been considered for a mesoportal bypass between January 2001 and January 2010.
  
  
  RESULTS
  Sixteen children were considered for mesoportal bypass, including four post reduced-size liver transplant patients. Ten children (63%) underwent WHVP. The Rex vein was clearly identified in 8/10 (80%). One Rex vein was seen at surgery but not demonstrated at WHVP. Six mesoportal bypasses were performed without WHVP, of which three (50%) were successful.
  
  
  CONCLUSIONS
  WHVP had a sensitivity of more than 80% and specificity of 100% in the preoperative patency assessment of the Rex vein.
authors.affiliation: Department of Radiology, Groote Schuur Hospital, University of Cape Town, Main Road, Cape Town 7925, South Africa. drajlawson@gmail.com
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Lawson
authors.forename: Paul
authors.initials: P
authors.lastname: Rischbieter
authors.forename: Alp
authors.initials: A
authors.lastname: Numanoglu
authors.forename: Nicky
authors.initials: N
authors.lastname: Wieselthaler
authors.forename: Steve J
authors.initials: SJ
authors.lastname: Beningfield
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003287:Contrast Media; D004932:Esophageal and Gastric Varices / Q000000981:diagnostic imaging* / Q000601:surgery; D005260:Female; D006801:Humans; D006975:Hypertension, Portal / Q000000981:diagnostic imaging* / Q000601:surgery; D007223:Infant; D008297:Male; D011169:Portal Vein / Q000000981:diagnostic imaging / Q000601:surgery; D011172:Portography / Q000379:methods*; D011300:Preoperative Care; D012189:Retrospective Studies; D014463:Ultrasonography
chemical_list: D003287:Contrast Media