Blood Supply of the Common Bile Duct
The common bile duct receives its blood supply entirely from the hepatic artery through a dual plexus system, with ascending marginal vessels from the posterior superior pancreaticoduodenal artery below and descending branches from the right hepatic artery above. 1, 2
Anatomical Organization
The CBD's arterial supply is organized into two interconnected plexuses that run along its entire length 2, 3:
- Paracholedochal plexus: Right and left marginal arteries that run longitudinally along the lateral margins of the duct (3 and 9 o'clock positions) 3, 4
- Epicholedochal plexus: A fine reticular network of vessels lying directly on the ductal surface 3, 4
Major Arterial Contributors
The CBD receives blood from multiple sources that collectively form the plexuses 3:
- Posterior superior pancreaticoduodenal artery (supplies ascending marginal vessels from below) 2, 3
- Right hepatic artery (supplies descending branches from above) 2, 5
- Retroportal artery 3
- Gastroduodenal artery 3, 4
- Cystic artery (contributes to proximal portions) 3
These seven major arteries collectively provide 94.5% of the blood supply to the extrahepatic biliary system 3.
Regional Variations in Vascularity
The supraduodenal portion of the CBD has the poorest vascularization and is most susceptible to ischemic injury, while the retropancreatic, hilar, and intrahepatic portions have copious blood supply 4. This anatomical vulnerability explains why bile duct ischemia from arteriovenous shunting or vascular injury predominantly affects the mid-duct region 1.
Collateral Circulation at the Hilum
A critical collateral system exists at the hepatic hilum 2, 5, 6:
- The hilar plate arterial plexus (communicating arcade) connects the right and left hepatic arterial systems 2, 5, 6
- This plexus is located extrahepatically in the hilar plate with thin tributaries to the hilar bile duct 6
- On the left side, 55% originates from a segment IV artery; on the right side, 73% originates from the right anterior hepatic artery 6
- This collateral network allows the right hepatic duct to maintain blood supply even after right hepatic artery ligation 2
Clinical Significance
Because bile duct blood supply is derived entirely from the hepatic artery, arteriovenous shunting or arterial injury can lead to bile duct ischemia, resulting in chronic bile duct damage, cholestasis, and rarely catastrophic bile duct necrosis. 1 This anatomical principle underlies the serious complications seen in vasculobiliary injuries during cholecystectomy 1, 2.
The hepatic artery-dependent blood supply explains why interruption of the right hepatic artery alone is usually well tolerated (due to portal venous compensation for hepatic parenchyma), but combined vasculobiliary injuries lead to bile duct ischemia in 10% of cases 1.
Venous Drainage
The venous drainage parallels the arterial supply with two corresponding plexuses 4:
- Epicholedochal venous plexus on the ductal wall drains into the paracholedochal venous plexus (parabiliary venous system) 4
- These drain inferiorly to the posterior superior pancreaticoduodenal vein, gastrocolic trunk, and superior mesenteric vein, and superiorly to intrahepatic portal vein branches 4
- These pericholedochal venous plexuses constitute porto-portal collaterals that dilate in portomesenteric venous obstruction 4