Bile duct duplication as a cause of distal bowel gas in neonatal duodenal obstruction.

PURPOSE: The aim of this study is to investigate the clinical characteristics of cases of duodenal atresia (DA) which present with bowel gas distal to a typical double-bubble sign through an anomalous bile duct conduit. METHODS: Medical records of 57 neonates with duodenal obstruction (atresia or stenosis), presenting with a double-bubble sign and treated at our institute from 1978 to 2010, were retrospectively reviewed. RESULTS: Thirteen (23%) of 57 neonates presented with bowel gas distal to the double-bubble sign. Passage of gas through the duodenal stenosis may have occurred in 3 cases, whereas in 9 cases, gas may have bypassed the atresia through an anomalous bifurcated bile duct termination and through the pancreatic duct from the accessory to the main pancreatic duct in one case. A preoperative upper gastrointestinal series was performed in 9 cases, and an anomalous bifurcated bile duct conduit was demonstrated in 5 cases. Severe and prolonged cholestasis necessitating evaluation for biliary atresia was found in 2 patients with anomalous bile duct anatomy. CONCLUSIONS: Neonatal DA presenting with distal bowel gas via an anomalous bifurcated bile duct conduit is more common than initially thought and occurs more frequently than duodenal stenosis. These patients might be at risk for cholestasis, possibly owing to duodeno-biliary reflux through the ampulla.