choledochus

Choledochus, or the common bile duct (ductus choledochus in Latin), is a conduit of the biliary system that transports bile from the liver and gallbladder to the duodenum. It is typically formed by the junction of the common hepatic duct and the cystic duct, and in adults it measures about 7 to 8 centimeters in length. The duct courses through the hepatoduodenal ligament, lies posterior to the first part of the duodenum and the head of the pancreas, and terminates at the major duodenal papilla in the descending part of the duodenum, where its flow is regulated by the sphincter of Oddi.

Bile delivered by the choledochus aids the emulsification and digestion of fats. Obstruction of the duct, most commonly from choledocholithiasis (stones), but also from strictures or tumors, can cause cholestasis with jaundice, dark urine, pale stools, pruritus, and laboratory findings of elevated alkaline phosphatase and conjugated bilirubin. Diagnostic imaging includes ultrasound and magnetic resonance cholangiopancreatography (MRCP); endoscopic retrograde cholangiopancreatography (ERCP) is used for both diagnosis and treatment, such as stone extraction or biliary stenting.

Anatomic variations are not uncommon, with accessory or aberrant ducts and different drainage patterns described in some individuals. Surgical procedures in the region, notably cholecystectomy, carry a risk of ductal injury or misidentification. In medical and anatomical literature, choledochus is the Latin term for the common bile duct and is often used interchangeably with ductus choledochus.