Bile Duct Diseases
Your gallbladder stores bile until you eat, then releases bile into your small intestine to help digest food. Bile ducts are small drainage "pipes" that carry bile (a mix of cholesterol, acids, salts and waste products) from the liver to the gallbladder and from the gallbladder to the small intestine. A variety of diseases can affect your bile ducts. All block the bile ducts in some way, which is why the various diseases cause similar symptoms.
Gallstones are the most common cause of blocked bile ducts. Stones typically form inside the gallbladder and can block the common bile duct, a large drainpipe at the base of the liver. If the duct remains blocked, waste can collect in the bile duct system and in the bloodstream. Also, if bacteria above the blockage accumulates and backs up into the liver, it may cause a severe infection called ascending cholangitis. If a gallstone stops in between the gallbladder and the common bile duct, an infection called cholecystitis can occur.
Less common causes of blockages include cancers of the bile duct (cholangiocarcinomas) and strictures (scars that narrow the ducts after infection, surgery or inflammation). Other bile duct diseases are uncommon, and include primary sclerosing cholangitis and primary biliary cirrhosis. Typically diagnosed in mid-adulthood, these conditions create ongoing inflammation in the bile duct walls, which can narrow and scar the walls. These conditions have an inherited (genetic) component, although other factors seem necessary to trigger the disease. Primary sclerosing cholangitis is more common in men, and 75% of the time it is seen in people with inflammatory bowel disease (ulcerative colitis or Crohn's disease).
Primary biliary cirrhosis is more common in women, and is sometimes associated with autoimmune diseases such as Sjogren's syndrome, thyroiditis, scleroderma or rheumatoid arthritis. Biliary atresia is a rare form of bile duct blockage that occurs in some infants two weeks to six weeks after birth, a time when the bile ducts have not completed their development normally. The chronic conditions of primary sclerosing cholangitis, primary biliary cirrhosis and biliary atresia can result in inflammation and scarring of the liver, a condition known as cirrhosis.
Symptoms
Symptoms of a blocked bile duct may be abrupt and severe (for example, when a gallstone blocks the whole drainage system all at once), or they may appear slowly many years after bile duct inflammation started. Bile duct diseases cause some symptoms when waste products build up in the body. Other symptoms result from the bile ducts' failure to deliver certain digestive juices (bile salts) to the intestines, preventing the absorption of some fats and vitamins. Symptoms of a blocked bile duct include:
- Yellowing of the skin (jaundice) or eyes (icterus), from the buildup of a waste product called bilirubin.
- Itching (not limited to one area; may be worse at night or in warm weather)
- Light brown urine
- Fatigue
- Weight loss
- Fever or night sweats
- Abdominal pain, especially common on the right side under the rib cage
- Greasy or clay-colored stools
- A diminished appetite
Your doctor may suspect that you have a bile duct problem if you have any of the classic symptoms or if a blood test shows that you have a high level of bilirubin. Your doctor will take your medical history and examine you to look for clues that could explain damage to the bile ducts and liver. Because liver inflammation (hepatitis) and liver scarring (cirrhosis) can cause similar symptoms, your doctor will ask about your alcohol use, drug use and sexual practices, all of which can result in liver disease.
If you have gallstones, have had pancreatitis or abdominal surgery, or have symptoms of an autoimmune condition (such as arthritis pain, dry mouth or eyes, skin rashes or bloody diarrhea), tell your doctor. Because some medicines can slow drainage through the bile ducts, your medicines should be reviewed. You may need blood tests to measure your levels of alkaline phosphatase, bilirubin or gamma-glutamyltransferase. These are markers of bile duct obstruction. Other blood tests may suggest liver inflammation or cirrhosis. Occasionally, specialized blood tests may be helpful, such as antibody tests to diagnose primary biliary cirrhosis or primary sclerosing cholangitis, and a blood test that measures CA 19-9, which could indicate that you have cholangiocarcinoma.
Prevention
If you have gallstones, you can prevent bile duct blockage and serious infection (ascending cholangitis or cholecystitis) by having your gallbladder removed. This is done using small incisions in the abdomen, in a surgery called laparoscopic cholecystectomy. If you are overweight or have high cholesterol, you are at higher risk of developing gallstone. To avoid trouble, work toward a healthy weight through diet and exercise. Women who take birth control pills or hormone replacement therapy are at higher risk of gallstones and may factor this risk in their decision to use these medications. Although cholangiocarcinoma is uncommon, risks associated with developing it include smoking, eating a high carbohydrate diet and having gallstones. Certain parasite infections (Clonorchis sinensis and Opisthorchis viverrini, also known as Chinese liver fluke) can increase the risk of bile duct infections and cancers. If you travel to Southeast Asia, eat fish only if it is well cooked. If you do eat undercooked fish while traveling in this area, ask your doctor for a stool parasite test, especially if you have symptoms of weight loss or diarrhea.
Treatment
To treat a gallstone blockage accompanied by signs of persistent pain or infection, a gastroenterologist or surgeon can remove stones in the bile duct using endoscopic retrograde cholangiopancreatography. The endoscope cuts through the base of the common bile duct, allowing a stone to pass through. In some cases the endoscope may be used to remove the stone using wire loops. Doctors recommend that anyone with a bile duct blockage from a gallstone have his or her gallbladder removed to prevent another blockage. This same procedure can widen an area of scarred bile duct (a stricture) by inserting and expanding a wire coil (called a stent) within the duct. It's rare to find bile duct cancer early, but if it is found early, it can be treated with surgery.
When cancer is more advanced, surgery cannot totally remove the tumor. Surgical procedures can help cancer patients feel better, even if they cannot provide a cure. Surgery can reroute the bile duct to allow better drainage. Radiation treatments can help to shrink, but not cure, a bile duct tumor. Biliary atresia, the failure to develop normal bile ducts in infants, can be treated by surgery. One method uses a portion of the baby's intestines to substitute for missing segments of the bile duct. Another method requires rerouting the bile drainage and additional intestinal surgery. However, most babies with this condition continue to have inflammation due to poor drainage, and eventually develop scarring (cirrhosis) and require a liver transplant.
Because both primary biliary cirrhosis and primary sclerosing cholangitis cause the liver to get worse, a liver transplant is eventually needed for long-term survival. Several treatments may reduce symptoms or delay the progression of the disease. In primary biliary cirrhosis, the medicines ursodiol (Actigall), colchicine and methotrexate (Folex, Rheumatrex) can be effective. The most bothersome symptom in chronic bile duct disease, itching, can be reduced with medicine — cholestyramine (Questran) or colestipol (Colestid) — that prevents irritants in the gut from being absorbed. Another medicine, naloxone (Narcan), might neutralize irritants that cause itching. If greasy stools are a problem, a low-fat diet may be helpful. Doctors recommend multivitamin supplements to improve nutrition.
Credit: National Institute of Health.