Bile Duct Obstruction: What are the main causes?

What is biliary obstruction?

A biliary obstruction is a blockage of the bile ducts. The bile ducts carry bile from the liver and gallbladder through the pancreas to the duodenum, which is a part of the small intestine. Bile is a dark-green or yellowish-brown fluid secreted by the liver to digest fats. After you eat, the gallbladder releases bile to help in digestion and fat absorption. Bile also helps clear the liver of waste products.

Obstruction of any of these bile ducts is referred to as a biliary obstruction. Many of the conditions related to biliary obstructions can be treated successfully. However, if the blockage remains untreated for a long time, it can lead to life-threatening diseases of the liver.

TYPES OF BILE DUCTS

Types of bile ducts

You have several types of bile ducts. The two types of bile ducts in the liver are intrahepatic and extrahepatic ducts.

  • Intrahepatic ducts: Intrahepatic ducts are a system of smaller tubes within the liver that collect and transport bile to the extrahepatic ducts.
  • Extrahepatic ducts: The extrahepatic ducts begin as two parts, one on the right of the liver and the other on the left. As they descend from the liver, they unite to form the common hepatic duct. This runs directly toward the small intestine.

The biliary duct, or the duct from the gallbladder, also opens into the common hepatic duct. The bile duct from this point onward is known as the common bile duct or choledochus. Before emptying into the small intestine, the common bile duct passes through the pancreas.

CAUSES

What causes biliary obstruction?

A biliary obstruction may be caused by a number of factors involving the:

The following are some of the most common causes of biliary obstruction:

  • gallstones, which are the most common cause
  • inflammation of the bile ducts
  • trauma
  • a biliary stricture, which is an abnormal narrowing of the duct
  • cysts
  • enlarged lymph nodes
  • pancreatitis
  • an injury related to gallbladder or liver surgery
  • tumors that have reached the liver, gallbladder, pancreas, or bile ducts
  • infections, including hepatitis
  • parasites
  • cirrhosis, or scarring of the liver
  • severe liver damage
  • choledochal cyst (present in infants at birth)
RISK FACTORS

What are the risk factors?

The risk factors for biliary obstruction usually depend on the cause of the obstruction. The majority of the cases are a result of gallstones. This makes women more vulnerable to developing a biliary obstruction. Other risk factors include:

SYMPTOMS

What are the symptoms of biliary obstruction?

The symptoms of biliary obstruction can depend on the cause of the obstruction. People with biliary obstruction usually have:

DIAGNOSIS

How is a biliary obstruction diagnosed?

Various tests are available for people who may have a biliary obstruction. Based on the cause of the obstruction, your doctor may recommend one or more of the following tests.

Blood test

A blood test includes a complete blood count (CBC) and liver function test. Blood tests can usually rule out certain conditions, such as:

  • cholecystitis, which is an inflammation of the gallbladder
  • cholangitis, which is an inflammation of the common bile duct
  • an increased level of conjugated bilirubin, which is a waste product of the liver
  • an increased level of liver enzymes
  • an increased level of alkaline phosphatase

Any of these may indicate a loss of bile flow.

Ultrasonography

Ultrasonography is usually the first test performed on anyone suspected of a biliary obstruction. It allows your doctor to see the gallstones easily.

Biliary radionuclide scan (HIDA scan)

A hepatobiliary iminodiacetic acid scan, or HIDA scan, is also referred to as a biliary radionuclide scan. It uses radioactive material to provide valuable information about the gallbladder and any possible obstructions.

Cholangiography

A cholangiography is an X-ray of the bile ducts.

MRI Scan

An MRI scan provides detailed pictures of the liver, gallbladder, pancreas, and bile ducts.

Magnetic resonance cholangiopancreatography (MRCP)

Magnetic resonance cholangiopancreatography (MRCP) is used for the diagnosis of biliary obstructions and pancreatic disease.

Endoscopic retrograde cholangiopancreatography (ERCP)

An endoscopic retrograde cholangiopancreatography (ERCP) involves the use of an endoscope and X-ray. It’s both a diagnostic and therapeutic tool. It allows your surgeon to see the bile ducts and it’s also used in treatment. This tool is particularly helpful because your doctor can use it to remove stones and take biopsy samples if necessary.

TREATMENT

What is the treatment for biliary obstruction?

Treatment is aimed at correcting the underlying cause. The primary objective of medical or surgical treatment is to alleviate the blockage. Some of the treatment options include a cholecystectomy and an ERCP.

A cholecystectomy is the removal of the gallbladder if there are gallstones. An ERCP may be sufficient to remove small stones from the common bile duct or to place a stent inside the duct to restore bile flow. This is often used in cases where obstruction is caused by a tumor.

COMPLICATIONS

Complications of a biliary duct obstruction

Without treatment, biliary duct obstructions can be life-threatening. Possible complications that can arise without treatment include:

  • dangerous buildup of bilirubin
  • infections
  • sepsis
  • chronic liver disease
  • biliary cirrhosis

Contact your doctor if you develop jaundice or notice a change in color of your stool or urine.

PREVENTION

Can biliary obstruction be prevented?

Here are a few changes you can make to lower your chances of developing a biliary obstruction: