bile ducts overview

bile

a vital digestive fluid produced by the liver

what is the function of the biliary tree?

to provide a conduit for bile to drain from the liver into the small intestine

bile first accumulates in the:

small intrahepatic biliary radicles (part of the portal triads) that are located throughout the liver

each portal triad contains:

a small branch of the hepatic artery, portal vein, and intrahepatic ducts (biliary radicles)

from the biliary radicles, bile flows into:

either the right or left hepatic duct

the right and left hepatic ducts unite to form:

the common hepatic duct

the gallbladder is attached to the biliary tree by the:

cystic duct

spiral valves of Heister

small projections of tissue in the cystic duct that prevent it from collapsing or distending

what happens to the gallbladder when it is stimulated by cholecystokinin?

it contracts and empties bile into the biliary tree at the level of the proximal common bile duct

bile travels from the common bile duct toward the duodenum, where it meets the:

main pancreatic duct at the ampulla of Vater → pancreatic juices and bile mix

what is the correct order bile flows in?

liver → biliary radicles → right or left hepatic duct → common hepatic duct → cystic duct → gallbladder → common bile duct → ampulla of Vater → sphincter of Oddi → duodenum

how long should patients fast for before a sonogram of the biliary tree?

8 hours is optimal, but at least 4 hours before

what diameter of the common bile duct is considered abnormal?

if it exceeds 6 mm

for pts older than 60 yrs or pts who have had a cholecystectomy, what max diameter of the common bile duct is considered normal if they are asymptomatic?

max diameter of 10 mm

what lab values may be elevated if biliary obstruction or disease is present?

• ALT

• ALP

• serum bilirubin

• GGT

• urobilirubin

the intrahepatic ducts are considered dilated if they measure:

more than 2 mm

how is the duct measured?

inner-to-inner wall

what sonographic sign is associated with the enlargement of the common bile duct to the size of the adjacent portal vein within the porta hepatis?

“shotgun” or “parallel tube” sign

what sonographic sign is associated with the coexisting dilation of the common bile duct and pancreatic duct?

“double-duct” sign