Cystic duct
Ductus cysticus
The cystic duct is a short, tortuous duct (about 3–4 cm) that connects the neck of the gallbladder to the common hepatic duct. Its mucosa forms a spiral fold.
Overview
The cystic duct runs from the gallbladder neck, usually backwards, downwards and to the left, to join the right side of the common hepatic duct and form the bile duct. The level and pattern of the junction vary: it may be low, run parallel to the hepatic duct, or spiral around it.
Its mucosa forms a series of crescentic folds called the spiral fold (valve of Heister). This is not a true valve, but it keeps the duct from collapsing or over-distending and slows flow. Bile moves in both directions through the duct. Between meals, when the sphincter of Oddi is closed, it flows into the gallbladder. When CCK contracts the gallbladder, it flows out.
The cystic duct forms the inferior boundary of the cystohepatic triangle (of Calot), and it is the structure clipped and divided, with the cystic artery, during cholecystectomy.
- Location
Between the gallbladder neck and the common hepatic duct, in the free edge of the lesser omentum.
Anatomy
- Arterial supply
Cystic artery.
- Histology
Mucosa thrown into spiral folds and lined by columnar epithelium, with a thin fibromuscular wall.
Function
- Two-way conduit for bile between the biliary tree and the gallbladder.
Clinical significance
Stone impaction
A gallstone wedged in the cystic duct causes biliary colic (transient) or acute cholecystitis (persistent). A chronically obstructed gallbladder can fill with mucus (mucocele) or pus (empyema).
Cystic duct stump leak
Clip displacement after cholecystectomy causes bile leakage, biloma and bile peritonitis. It is usually managed with ERCP and a stent.
Compiled from standard anatomy and physiology references — see the Digestive System sources. For education only; not medical advice.