Hepatic portal venous gas caused by blunt abdominal trauma: is it a true ominous sign of bowel necrosis? Report of a case.

A case of transient portal venous gas in the liver following blunt abdominal trauma is described. Computed tomography (CT) demonstrated hepatic portal venous gas 4 h after the injury. An exploratory laparotomy revealed segmental necrosis of the small intestine with a rupture of the bladder. Pneumatosis intestinalis was evident on the resected bowel. A histopathologic study revealed congestion and bleeding in the bowel wall and a great deal of the mucosa had been lost because of necrosis. However, neither thrombus nor atherosclerotic changes were observed in the vessels. A bacteriological examination demonstrated anaerobic bacteria from the bowel mucosa, which was most likely to produce portal venous gas. Although the present case was associated with bowel necrosis, a review of literature demonstrated that portal venous gas does not necessarily indicate bowel necrosis in trauma patients. There is another possibility that the portal venous gas was caused by a sudden increase in the intra-abdominal pressure with concomitant mucosal disruption, which thus forced intraluminal gas into the portal circulation in the blunt trauma patients.