Cystic duct

Anatomy and Topography

The cystic duct is a part of the hepatoduodenal ligament (lig. hepatoduodenale), which occupies the rightmost position in the lesser omentum.

• Origin: originates from the neck of the gallbladder (collum vesicae felleae), forming two bends in this region, and then runs superiorly and to the right.
• Termination: joins the common hepatic duct (ductus hepaticus communis) to form the common bile duct (ductus choledochus).
• Variations of insertion: the junction can occur at an acute or obtuse angle; a parallel course with the common hepatic duct for some distance and a spiral course around it are possible.
• Syntopy within the ligament: the proper hepatic artery (a. hepatica propria) is located to the left, and the portal vein (v. portae) lies posteriorly between the artery and the bile duct.

Wall structure

The wall of the cystic duct has the following features:

• Muscular layer: poorly developed and consists of longitudinal and circular layers.
• Mucous membrane: forms a spiral fold (plica spiralis).
• Submucosa: mucous glands (glandulae mucosae ductulorum biliarium) are located in the walls of the extrahepatic bile ducts.

Function (bile flow mechanism)

The cystic duct ensures bile transport depending on the phase of digestion:

• Outside of digestion: the orifice of the common bile duct is closed, therefore bile flows retrogradely through the cystic duct into the gallbladder.
• During digestion: bile is expelled through the cystic duct into the common bile duct and then into the duodenum.

Clinical significance: Biliary colic

In cholelithiasis, a gallstone may become impacted in the cystic duct. This causes obstruction and reflex spasm, leading to increased intraluminal pressure and the development of biliary colic.

• Character of pain: pronounced, distending, and fairly constant. The term "colic" is not entirely accurate here, as the pain does not have wave-like intensification, but rather increases rapidly and reaches a "plateau".
• Localization and irradiation: epigastrium and right hypochondrium; the pain radiates under the right scapula, to the interscapular region, the right shoulder, and the right half of the neck.
• Trigger factors: intake of fatty or fried foods, an unusually large meal after prolonged restriction, bumpy rides, trunk bending, physical exertion, and psycho-emotional stress. It often occurs at night.
• Symptoms: accompanied by nausea and vomiting that do not bring relief, as well as autonomic reactions: changes in blood pressure, tachycardia, or bradycardia.

Surgical significance: Cholecystectomy

Isolation and division of the cystic duct is a step in the gallbladder removal surgery (cholecystectomy).

• Critical view of safety (CVS): it is necessary to expose the neck and the lower third of the body of the gallbladder on all sides and separate part of the gallbladder from the hepatic bed. Structures can be divided only after it has been established that exclusively two tubular structures—the cystic duct and the cystic artery (a. cystica)—approach the isolated part.
• Intraoperative diagnostics: a thin polyethylene catheter or a special cannula is inserted through the incised cystic duct to perform cholangiography, cholangiomanometry, or debitometry.
• Stump management: the duct is ligated 0.5 cm away from the site of its insertion into the common bile duct.
• Do not ligate flush: there is a risk of narrowing the lumen of the common bile duct.
• Do not leave an excessively long stump: there is a risk of its dilation and stone formation.

Class and exam questions

What else to study on this topic

• Gallbladder (vesica fellea)
• Common bile duct (ductus choledochus)
• Hepatoduodenal ligament (lig. hepatoduodenale)
• Cholelithiasis and biliary colic

Other topics in the "Anatomical Structures" section

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