Biliary Obstruction (Blocked Bile Duct)

How bile flows and what a blockage does

The liver makes about 500 to 1,000 ml (1 to 2 pints) of bile a day. It flows through small ducts in the liver into the common hepatic duct, is stored in the gallbladder, and enters the duodenum through the common bile duct, which joins the pancreatic duct at the ampulla of Vater.

When the duct is blocked:

• bilirubin (a yellow pigment) builds up in the blood, causing jaundice
• the kidneys excrete it, so urine turns dark
• stools lose their brown color and become pale (see pale stools)
• bile salts build up in the skin, causing itching
• fat and fat-soluble vitamins (A, D, E, K) are poorly absorbed, which can affect blood clotting
• stagnant bile can become infected (cholangitis)

Causes

Inside the duct

• Gallstones (choledocholithiasis): stones that move from the gallbladder into the bile duct, the most common cause. See gallstones.
• Bile duct cancer (cholangiocarcinoma).
• Parasites: liver flukes and roundworms in some parts of the world.
• Blood clots or sludge.

In the duct wall

• Strictures after gallbladder surgery, injury or chronic inflammation.
• Primary sclerosing cholangitis: inflammation and scarring of the bile ducts, often with ulcerative colitis.
• IgG4-related sclerosing cholangitis.
• Choledochal cysts (abnormal dilations present from birth).

Pressure from outside

• Pancreatic cancer in the head of the pancreas: classically painless jaundice with weight loss.
• Pancreatitis and pancreatic cysts.
• Enlarged lymph nodes or tumors of the duodenum or ampulla.
• Mirizzi syndrome: a gallstone in the gallbladder neck pressing on the bile duct.

In infants

Biliary atresia, in which the bile ducts are absent or blocked, causes jaundice beyond 2 weeks of age with pale stools and needs surgery early.

Symptoms

• yellow skin and eyes
• dark urine
• pale, gray or clay-colored stools
• generalized itching, often worse at night
• pain under the right ribs or in the upper middle abdomen, especially with stones
• nausea, vomiting and loss of appetite
• fever and chills if infected
• weight loss and fatigue with tumors

Jaundice from a stone usually comes with pain and may fluctuate. Jaundice from cancer is more often gradual and painless.

Complications

• Acute cholangitis: infection behind the blockage. The classic triad is fever, jaundice and right upper abdominal pain. It can progress to sepsis and is treated urgently with antibiotics and drainage.
• Gallstone pancreatitis.
• Secondary biliary cirrhosis from long-standing blockage.
• Bleeding problems from vitamin K deficiency.
• Kidney injury in severe jaundice.

Diagnosis

1. Blood tests: raised bilirubin (mostly conjugated), alkaline phosphatase and GGT, sometimes raised ALT and AST; blood count and inflammatory markers; clotting tests; lipase; tumor markers such as CA 19-9 in some cases.
2. Abdominal ultrasound: the first imaging test. It shows gallstones and dilated bile ducts.
3. MRCP: a non-invasive MRI that maps the bile and pancreatic ducts.
4. Endoscopic ultrasound (EUS): a scope with an ultrasound probe in the duodenum; very good at finding small stones and pancreatic tumors, and allows biopsy.
5. CT scan: for tumors and staging.
6. ERCP: an endoscope passed into the duodenum to inject dye into the ducts. It is mainly used for treatment rather than diagnosis because it carries risks such as pancreatitis.

Treatment

Gallstones in the bile duct

• ERCP with sphincterotomy: a small cut at the duct opening allows stones to be swept out with a balloon or basket. Large stones may be broken up first.
• Gallbladder removal (laparoscopic cholecystectomy), usually during the same admission or soon after, to prevent recurrence.
• Sometimes the duct is explored during gallbladder surgery instead.

Cholangitis

IV fluids, antibiotics and urgent biliary drainage by ERCP, or through the skin if ERCP is not possible.

Strictures and tumors

• Stents (plastic or metal tubes) placed by ERCP or through the skin to relieve jaundice and itching.
• Surgery for removable tumors, such as a Whipple procedure for pancreatic head cancer.
• Chemotherapy and other cancer treatments.
• Balloon dilation of benign strictures.

Symptom relief

Itching is eased by relieving the blockage. Medicines such as cholestyramine can help meanwhile. Vitamin K may be given before procedures.

Outlook

Stones and benign strictures usually have an excellent outcome once the duct is cleared. Outcomes for cancer depend on the type and stage; stents greatly improve quality of life even when cure is not possible.

Frequently asked questions

What are the symptoms of a blocked bile duct?

The main symptoms are yellow skin and eyes, dark urine, pale stools, itching, and pain in the upper right abdomen. Nausea and loss of appetite are common. Fever and chills suggest the blocked bile has become infected, which is an emergency.

What is the most common cause of biliary obstruction?

Gallstones that move from the gallbladder into the common bile duct are the most common cause. Other causes include bile duct narrowing after surgery or inflammation, pancreatitis, pancreatic cancer, bile duct cancer and primary sclerosing cholangitis.

Can a blocked bile duct clear on its own?

A small stone sometimes passes into the intestine on its own, and symptoms settle. Because stones often recur and can cause cholangitis or pancreatitis, doctors usually remove remaining stones with ERCP and recommend gallbladder removal.

Is a blocked bile duct serious?

It can be. Untreated blockage can lead to infection (cholangitis), sepsis, pancreatitis and liver damage. With prompt treatment, most blockages caused by stones resolve well. Painless jaundice needs urgent investigation because it can be a sign of cancer.

What is ERCP?

ERCP is a procedure in which a flexible endoscope is passed through the mouth into the duodenum to reach the bile duct opening. Doctors inject dye to see the ducts on X-ray, remove stones, widen narrowings and place stents. It is done under sedation and usually takes under an hour.