Gas in the portal vein: a report of two cases.

Gas in the portal venous system was detected on plain roentgenograms of the abdomen in two women aged 61 and 72 years, respectively. Both patients had intestinal necrosis, due in one instance to a small bowel volvulus around a mesenteric band, and in the second instance to occlusion of the celiac axis, superior and inferior mesenteric arteries. In the first patient, the portal venous gas was detected before surgery, and in the second case the gas was observed at laparotomy and was visualized on radiographs of the abdomen taken shortly after death. Both patients died. Portal venous gas can be distinguished radiologically from air in the bile ducts by its characteristic slender branching gas pattern in the periphery of the liver substance. The presence of portal gas in the adult indicates intestinal necrosis in the majority of cases and should lead to early operative intervention.