Common bile duct (bile duct)

Main duct or vein

About 7-8 cm long, formed by union of the common hepatic and cystic ducts. Its four parts are supraduodenal (free edge of the lesser omentum, anterior to the portal vein and right of the hepatic artery proper, forming the anterior boundary of the epiploic foramen), retroduodenal (behind the first part of the duodenum with the gastroduodenal artery to its left and the IVC behind), pancreatic (in a groove on, or within, the posterior head of the pancreas) and intraduodenal (through the wall of the second part of the duodenum to join the main pancreatic duct).

Traced from the start

  1. Right hepatic ductLeft hepatic duct
  2. Gallbladder
  3. Common hepatic ductCystic duct
  4. Common bile duct (bile duct)

Detail

Length
About 7-8 cm
Diameter
Up to 6 mm on ultrasound; allow about 1 mm per decade after 60 and up to 10 mm after cholecystectomy
Lesser omentum relations
Bile duct anterior-right, hepatic artery proper anterior-left, portal vein posterior; epiploic foramen behind
Parts
Supraduodenal, retroduodenal, pancreatic, intraduodenal

When it goes wrong

Gallstone migrating into the bile duct (choledocholithiasis)

Colicky right upper quadrant pain with obstructive jaundice: dark urine, pale stools, pruritus; conjugated hyperbilirubinaemia with ALP and GGT rising more than the transaminases; dilated ducts on ultrasound; cleared at ERCP

Infected bile trapped behind an obstruction (ascending cholangitis)

Charcot's triad of fever with rigors, jaundice and right upper quadrant pain; Reynolds' pentad adds hypotension and confusion, demanding antibiotics and urgent biliary decompression

Carcinoma of the head of the pancreas compressing the intrapancreatic bile duct

Painless progressive jaundice with weight loss and a palpable distended gallbladder; dilated bile and pancreatic ducts give the 'double duct sign' on imaging

Practise this structure

1 question in the bank tagged Bilirubin.