Gas in the bile ducts (pneumobilia) in emphysematous cholecystitis.

Gas in the biliary ducts (pneumobilia) was demonstrated in three cases of emphysematous cholecystitis. Pneumobilia is usually secondary to a spontaneous internal biliary fistula or incompetent sphincter of Oddi, and is rarely considered a manifestation of emphysematous cholecystitis. The presence of gas in the biliary ducts in these cases suggests that the cystic duct is patent, allowing gas to escape from the gallbladder lumen. The pathophysiology of emphysematous cholecystitis is discussed and an ischemic etiology considered.