Biliary stones are like gallstones, except they are located in the bile ducts. Biliary stones can form in the bile ducts or they can migrate from the gallbladder, where gallstones form, to the bile ducts and become trapped. Bile is formed in the liver, where it helps with the digestion of fatty foods.
When the body is ready to remove bile, it travels through the bile ducts to the small intestine to be removed. If you’re in the middle of a meal, bile will go directly to the small intestine from the liver. If you’re not eating, but the liver still needs to move bile, it will go to the gallbladder to be stored.
There are 3 bile ducts, and one of them is connected directly to the gallbladder, making it easy for a gallstone to turn into a biliary stone. Gallstones are formed one of two ways-out of cholesterol in the bile (cholesterol stones) or out of a mixture of calcium and bilirubin (pigment stones). Bilirubin is formed when old red blood cells are broken down by the body. Since cholesterol, calcium, and bilirubin are all found in bile, it makes sense that stones can form in the bile ducts and the gallbladder.
It’s possible to go for a long time without any symptoms of biliary stones. If the stones are small enough and not blocking the bile ducts, someone probably wouldn’t feel anything. Informally, these are called silent stones. However, if a stone is big enough to block a bile duct, symptoms may include:
Symptoms of biliary stones can come and go over the course of weeks, months, and years.
Biliary stones can form when there is too much bilirubin, cholesterol or not enough bile salts or when the gallbladder does not empty completely or enough.
Risk factors for biliary stones include:
A doctor will gather a medical history and conduct a thorough physical exam when assessing the possibility of biliary stones. To get a definitive diagnosis, there are two main imaging techniques that can be used.
An MRCP is a magnetic resonance cholangiopancreatography. This imaging tool is a more specific version of a magnetic resonance imaging (MRI) scan. While it uses the same technology to produce detailed images, it focuses on the bile ducts, gallbladder, pancreas, and liver.
An endoscopic ultrasound uses an endoscope – a long, flexible tube- to get a better look at the digestive tract. The endoscope goes through the patient’s mouth to the abdomen and uses ultrasound technology to generate a picture of the abdomen. Any biliary stones will be visible.
Complications can include:
Endoscopic retrograde cholangiopancreatography (ERCP) is used to treat biliary stones. In this procedure, a doctor will insert an endoscope in your abdomen through your mouth. The mechanics of ERCP are similar to the mechanics of MRCP, a described tool for diagnosis. Using the endoscope, the doctor will inject a dye into the bile ducts. This dye will allow a doctor to see the bile ducts using an x-ray. The doctor will then locate the biliary stones and remove them.