title: Patent abdominal subcutaneous veins caused by congenital absence of the inferior vena cava: a case report.
abstract: BACKGROUND
  Patent paraumbilical and abdominal subcutaneous veins are found frequently as collaterals in patients due to portal hypertension mainly in liver cirrhosis.
  
  
  METHODS
  For evaluation of portal hypertension in a 72-year-old Caucasian man without liver cirrhosis, magnetic resonance imaging with gadolinium contrast-enhancement was performed and demonstrated a missing inferior vena cava. A blood return from the lower extremities was shown through enlarged collateral veins of the abdominal wall, vena azygos and hemiazygos continuation, and multiple liver veins emptying into the right cardiac atrium. We describe a rare case of abdominal subcutaneous wall veins as collaterals caused by a congenitally absent infrarenal inferior vena cava with preservation of a hypoplastic suprarenal segment.
  
  
  CONCLUSIONS
  Knowledge of these congenital variations can be of clinical importance and it is imperative for the reporting radiologist to identify these anomalies as they can have a significant impact on the clinical management of the patient.
authors.affiliation: Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, A-8036 Graz, Austria. w.schnedl@dr-schnedl.at.
authors.forename: Wolfgang J
authors.initials: WJ
authors.lastname: Schnedl
authors.forename: Pia
authors.initials: P
authors.lastname: Reittner
authors.forename: Robert
authors.initials: R
authors.lastname: Krause
authors.forename: Rainer W
authors.initials: RW
authors.lastname: Lipp
authors.forename: Erwin
authors.initials: E
authors.lastname: Tafeit
authors.forename: Sandra J
authors.initials: SJ
authors.lastname: Wallner-Liebmann