Diagnostic Ultrasound - Abdomen and Pelvis

Biliary System
Left hepatic duct
Right hepatic duct
ANATOMIC VARIATIONS OF BILIARY TREE
Accessory right hepatic
(joining common hepatic duct)
Anatomy: Abdomen
Cystic duct
Accessory left hepatic (joining
common bile duct)
Accessory right hepatic
(joining cystic duct)
Accessory right hepatic
(joining common bile duct)
Conventional junction of cystic
and common hepatic ducts
Low insertion of cystic duct
Spiral course of cystic duct
around common hepatic duct
Cystic and common bile ducts
in common sheath
(Top) Graphic shows the conventional arrangement of the extrahepatic bile ducts, but variations are common (20% of population) and
may lead to inadvertent ligation or injury at surgery (such as during cholecystectomy), where the cystic duct is clamped and transected.
Most accessory ducts are on the right side and usually enter the common hepatic duct, but they may enter the cystic or common bile
duct. Accessory left ducts enter the common bile duct. While referred to as "accessory," these ducts are the sole drainage of bile from at
least 1 hepatic segment. Ligation or laceration can lead to significant hepatic injury or bile peritonitis. (Bottom) The course and
insertion of the cystic duct are highly variable, leading to difficulty in isolation and ligation at cholecystectomy. The cystic duct may be
mistaken for the common hepatic or common bile duct.
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