Differential diagnosis and clinical relevance of pneumobilia or portal vein gas on abdominal x-ray.

The purpose of the article is to present the differential diagnostic criteria between pneumobilia (air in the biliary system) and portal vein gas on abdominal x-ray. Differential diagnosis is essential because of its influence on patient management. Two patients are presented, one with pneumobilia and the other with portal vein gas on abdominal x-ray, with review of the relevant literature. Pneumobilia is often iatrogenic and even in cases of cholecystitis it is never a sole indication for emergency surgery. Patients with pneumobilia on abdominal x-ray can always be investigated further. On the other hand, the presence of air in portal vein is in most cases a sign of acute mesenteric ischemia. In adults with abdominal pain indicating intestinal ischemia (pain that is 'out of proportion' to clinical abdominal examination findings), it is an indication for emergency exploratory laparotomy. It is vital to act early when intestinal ischemia is suspected.