Anomalous biliary ducts associated with duodenal atresia.

Duodenal atresia is rarely associated with anomalous biliary ducts that permit communication between the proximal and distal duodenal segments. Two such cases are presented herein and the literature is reviewed. Although the typical radiographic pattern of duodenal atresia is the "double bubble" sign with absence of distal bowel gas, air may be present in the distal bowel when anomalous bile ducts provide a conduit around the atretic segment. Contrast studies are generally not performed in the typical clinical and radiographic evaluation of duodenal atresia; however, an upper gastrointestinal series may be useful in defining the more complex anomaly. Clinical presentation may occur relatively late if the biliary communication is large enough to permit passage of some milk or formula. Care should be taken at surgery to avoid obstruction or injury to the anomalous bile ducts, and operative cholangiography may be useful to document continued bile duct patency following repair of the atresia. Theories of the etiology of this anomaly relate to interference with recanalization of the duodenum by the process of hepaticopancreatic duct formation and persistence of the primitive "dual duct" stage.