common hepatic duct
Meaning of common hepatic duct: One short segment of the plumbing that drains bile, defined entirely by the two junctions at either end of it.
Definition of common hepatic duct
The common hepatic duct is the short tube that carries bile away from the liver. It begins just outside the liver, where the right and left hepatic ducts join, and it ends where the cystic duct arrives from the gallbladder. Below that meeting point the same channel continues under a new name, the common bile duct, on its way to the intestine.
Where does it sit in the biliary tree?
Bile is made continuously by liver cells and drains through channels that merge like streams into a river. Tiny channels inside the liver feed the right and left hepatic ducts, one from each half. Those two meet just outside the liver to form the common hepatic duct. It runs down a short distance and is joined by the cystic duct, the side branch running to and from the gallbladder. From that junction onward the tube is called the common bile duct, which passes behind the pancreas and empties into the first part of the small intestine.
Why does the name change at that point?
| Segment | Runs from | Runs to | Carries |
|---|---|---|---|
| Right and left hepatic ducts | Inside each half of the liver | Their meeting point | Bile from one side only |
| Common hepatic duct | That meeting point | The cystic duct junction | Bile straight from the liver |
| Common bile duct | The cystic duct junction | The small intestine | Bile from liver and gallbladder |
The distinction is practical rather than fussy. Above the junction the tube carries only fresh liver bile, while below it the concentrated bile stored in the gallbladder joins the flow.
What goes wrong here?
Anything blocking the duct backs bile up into the liver and into the blood, producing yellow skin and eyes, pale stools, dark urine and itching. A gallstone can lodge in the duct, and a stone stuck in the cystic duct can press on the common hepatic duct from outside. Tumors of the bile duct, the gallbladder or the head of the pancreas can narrow or invade it. Injury during gallbladder surgery is a recognized complication, because the branching pattern here varies more between people than a textbook diagram suggests.
How is it examined?
Ultrasound is usually the first look and shows whether the ducts above a blockage have widened. A magnetic resonance scan tuned to fluid maps the whole tree without instruments. An endoscope passed to the duct opening in the intestine can image the system with injected dye and clear a blocked duct during the same procedure.
Used in a sentence
The scan showed dilated intrahepatic ducts with a stone at the level of the common hepatic duct.
Good to know
The arrival of the cystic duct is what separates the common hepatic duct from the common bile duct, and the branching pattern here varies enough between people that duct injury is a recognized complication of gallbladder surgery.
Word origin
Where “common hepatic duct” comes from
Hepatic comes from the Greek hepar, meaning liver, and duct from the Latin ducere, meaning to lead.