Complex extrahepatic portocaval shunt with unusual caval features in a cat: computed tomographic characterisation.

A two-year-old, neutered male domestic shorthair cat was evaluated for a history of urate calculi, and neurologic signs. Diagnostic imaging revealed an elongated and tortuous single extrahepatic portosystemic shunt which appeared to receive normal tributaries of the caudal vena cava. Surgical correction of the shunt was carried out using cellophane banding. Eight months following surgery, clinical signs had resolved. Computed tomographic angiography allows thorough, rapid imaging of complex vascular anomalies to aid proper surgical correction. Errors in the formation of the portal vein and caudal vena cava can produce complex anomalies of the abdominal vasculature. Persistence of the embryologic left subcardinal vein is proposed to account for the lesion.