Bile Duct Obstruction
Obstruction of the bile duct causes JAUNDICE
What is bile ?
Bile is a liquid released by the liver. It is a mixture of several chemicals and contains cholesterol, a yellow pigment called bilirubin and bile salts. Bile passes out of the liver through tubes known as bile ducts and is stored in the gallbladder. The gallbladder is connected to the intestine by a large bile duct known as common bile duct. After a meal, the gallbladder contracts and bile is released into the small intestine. Bile salts present in the bile help in digestion of fat within the intestines. When the bile ducts become blocked, bile accumulates in the liver. The accumulated bile in the liver leaks into the blood stream and this leads to an increase in the level of bilirubin in the blood causing jaundice (yellow color of the skin). Accumulation of bile salts in the blood causes pruritus (itching of the skin).
What is bile duct obstruction ?
It is the blockage in the tubes that carry bile from the liver to the gallbladder and small intestine.
What are the possible causes of a blocked bile duct ?
- Stones in the common bile duct
- Cancer of the bile ducts or pancreas
- Narrowing (stricture) of the common bile duct due to previous gallbladder surgery
- Cysts of the bile duct
- Worms in the bile duct (rarely)
What are the symptoms of bile duct obstruction ?
- Abdominal pain in the upper right side
- Dark urine
- Itching of the skin
- Jaundice (yellow colour of the skin and eyes)
- Nausea and vomiting
- Pale colored stools
What are tests done to confirm bile duct obstruction ?
Liver function tests can suggest if there is a blockage of the bile duct. Usually the bilirubin level in the blood is increased and there is elevation of liver enzymes (alkaline phosphatase, GGT, AST and ALT). An ultrasound scan is a simple test that can show a enlarged and dilated bile duct. After determining that the bile duct is blocked, it is important to determine the cause of blockage. Stones causing bile duct obstruction can be seen on ultrasound scan. Frequently other specialized radiological investigations are required to determine the exact cause of blockage. These tests include abdominal CT scan, Magnetic resonance cholangiopancreatography (MRCP), Endoscopic retrograde cholangiopancreatography (ERCP), Endoscopic ultrasound (EUS), Percutaneous trans-hepatic cholangiography (PTC) and Radionuclide scan (HIDA scan).
How is bile duct obstruction treated ?
Treatment depends upon the cause of the obstruction. Stones in the bile duct can be removed by an endoscopic procedure known as ERCP. If there are stones present in the gallbladder in addition to the bile duct, then the gallbladder will usually be surgically removed by a procedure known as cholecystectomy. If the cause of bile duct obstruction is cancer, then a major surgery is required to remove the cancer. In some patients, the cancer may be advanced and cannot be removed by surgery. In such cases a plastic tube (known as stent) may be placed in the bile duct across the blocked area to relieve the obstruction. This procedure is known as bile duct stenting and this can be done endoscopically or radiologically by piercing the skin and abdominal wall overlying liver.
What are the complications of untreated bile duct obstruction ?
Untreated bile duct obstruction can lead to progressive jaundice and severe itching. Frequently patients develop infection in the blocked ducts that spreads to the liver and causes high fever with shivering. Such an infection is known as acute cholangitis and this can be life threatening if not diagnosed and treated promptly. Prolonged obstruction of the bile duct over several months can cause permanent damage to the liver known as biliary cirrhosis, that can eventually lead to liver failure.