Liver and Biliary Tree

Common Bile Duct

The CBD is 7-8 cm long and normally no more than 6 mm in diameter in adults. In elderly patients, the duct will dilate 1 mm per decade after 60, i.e. 7 mm at 70 years, 8 mm at 80 years and so on.

The CBD has three parts to its course. It tapers as it pierces and opens into the medial wall of the second part of the duodenum, about halfway down its length.

The CBD is usually joined by the main pancreatic duct, and together they open into a small ampulla in the duodenal wall, called the ampulla of Vater. The ampulla opens into the lumen of the duodenum by means of the major duodenal papilla.

Circular muscle fibres, known as the sphincter of Oddi, surround the terminal parts of both ducts and the ampulla.

The CBD and the main pancreatic duct share a common papilla in 60%, the remainder have separate orifices.

Blood Supply

The arterial supply of the bile duct is important due to its potential vulnerability during surgery. Furthermore, it is quite complex with seven arteries described and multiple anastomoses between them. The most important of these arteries are:

i. The posterior superior pancreaticoduodenal artery and gastroduodenal artery supplying the retroduodenal part of the duct
ii. The cystic artery supplying the middle part of the duct
iii. The right hepatic artery supplying the middle and proximal part of the duct
iv. The retro-portal artery
v. The 3 and 9 o’clock arteries
 
The arterial supply to the bile duct is complex and appreciation of this is important in preventing ischaemic injury to it during biliary surgery.
Scroll to Top