The common bile duct connects the gallbladder to the duodenum. This common bile duct is a channel whose function is to discharge bile into the duodenum, the organ which makes up the digestive system. Bile thus plays an important role in digestion. The common bile duct, which therefore brings this bile to the initial part of the small intestine, is formed by the fusion of the common hepatic duct and the cystic duct. Most bile duct disorders are the result of gallstones, these small pebbles sometimes forming due in particular to the clogging of the gallbladder with gallstones, which calcify to become pebbles.

The common bile duct is formed by the fusion of the common hepatic duct and the cystic duct. Thus, the bile canaliculi, these small ducts which collect the bile produced by the liver cells (cells also called hepatocytes), merge to form bile ducts. Again, these bile ducts merge together and give rise to the right hepatic duct as well as the left hepatic duct, which in turn join together to form the common hepatic duct. It is this common hepatic duct which, joined by the cystic duct, a kind of pocket coming from the bilary vesicle, will form the common bile duct. From the common bile duct, bile will be able to enter the duodenum, that initial part of the small intestine that follows the stomach. The bile emitted via this common bile duct will thus participate in the digestive functions of the body.

Physiologically, the common bile duct thus makes it possible to discharge the bile through the hepato-pancreatic bulb into the duodenum. Penetrating into this constituent organ of the digestive system, the bile will therefore participate in digestion. In fact, the duct that carries the bile secreted by the liver is called the main bile duct leaving the liver and is called common bile duct once it is joined by the cystic duct, that is to say that of the gall bladder.

Role of bile in digestion

Bile is produced in the liver before being carried through the bile ducts and then discharged via the common bile duct. The liver produces around 500-600 mL of bile every day. This bile is made up mainly of water and electrolytes, but also of organic compounds, and in particular bile salts. These bile salts, once secreted in the initial part of the small intestine, the duodenum, then have the essential functions of making soluble the liposoluble vitamins, but also the fats which have been ingested: this therefore facilitates their digestion as well as their absorption. . In addition, the bile also contains bile pigments, these compounds which result from the destruction of red blood cells and a fraction of which will be eliminated from the body via the stool.

Gallbladder contraction

Eating releases hormones from the gut. In addition, certain nerves are stimulated (called cholinergic nerves), which causes the gallbladder to contract. This will then evacuate 50 to 75% of its content in the duodenum, via the common bile duct. Finally, the bile salts thus circulate from the liver to the intestine and then back to the liver ten to twelve times a day.

Most bile duct disorders are the result of gallstones, those small stones that form in the bile ducts. Ultimately, three main diseases of the bile ducts are identified: biliary retention, tumors and stones.

• In the event of biliary retention, the bile does not access the duodenum. It stagnates in the common bile duct or in the gall bladder. This blockage causes excess pressure in the bile ducts. This causes pain of hepatic colic;
• This phenomenon of biliary retention can be caused by a tumor in the bile ducts or in the bile of the pancreas. These tumors can be benign or malignant. In addition, they can affect the bile ducts from both inside and outside the liver;
• Gallstones developing in the gallbladder are caused by the clogging of the gallbladder with gallstone mud, which calcifies and becomes pebbles. So, lithiasis of the main bile duct is characterized by the presence of stones in the bile ducts. This gallstones can, more precisely, be caused by the appearance of insoluble cholesterol salts in the bile ducts. Sometimes this gallstone migrates into the main bile duct, the common bile duct. It then causes a painful attack, which may be followed by fever as well as jaundice due to blockage of the common bile duct.

The treatment of lithiasis of the common bile duct is most often multidisciplinary.

• On the one hand, a cholecystectomy (removal of the gallbladder) makes it possible to suppress the formation of gallstones;
• On the other hand, the stone present in the common bile duct can be removed during this cholecystectomy, or even in the days following the intervention by a gastroenterologist, during an operation called endoscopic sphincterotomy.

The removal of the gallbladder does not cause any major physiological change. In addition, it will not be necessary to follow a special diet afterwards.

A choledochal lithiasis is sometimes asymtomatic: it can then be discovered during a check-up. When it causes biliary obstruction, also called cholestasis, it causes jaundice (jaundice) as well as pain of the liver colic type. The diagnosis can sometimes be suspected by examination by the surgeon.

In-depth examinations will be necessary:

• At the biological level, there may be signs of cholestasis, such as an increase in bilirubin, gamma GT (GGT or Gammaglutamyl-transferase), and PAL (alkaline phosphatase) as well as that of transaminases;
• The abdominal ultrasound may show dilation of the bile ducts;
• An endoscopic ultrasound, possibly associated or not with a bili-MRI will be frequently performed, with the aim of visualizing the lithiasis and therefore confirming the diagnosis.

Etymologically, the term cholédoque comes from the Greek “kholé” which means “bile”, but also “gall” and “anger”. Historically, it should be noted that in Antiquity, and until the discoveries in human physiology which made medicine truly scientific, it was customary to distinguish what were called the four “humors” of Hippocrates. The first was blood: coming from the heart, it defined the blood character, which designates a strong and toned character, and also extremely sociable. The second was pituitis which, attached to the brain, was correlated with lymphatic temperament, also called phlegmatic. The third of the humours proposed by Hippocrates was yellow bile, originating in the liver, which was associated with an angry temper. Finally, the black or atrabile bile, coming from the spleen, was held responsible for the melancholy character.