An important task of the liver is producing and excreting bile. This yellow-green bitter tasting fluid flows into the intestine through the bile ducts. The bile ducts in the liver are like the branches on a tree, that come together just below the stomach. A side branch leads to a sack for storing bile, called the gallbladder.

Gallbladder disease is a common type of illness involving the biliary tree. Less common, but significant, is cystic disease of the biliary tree. This can take several forms: (1) cysts in the main trunk (choledochal cysts), (2) cysts (or lakes) in the small branches within the liver (Caroli's syndrome) or (3) cysts in the liver separate from the biliary tree (polycystic liver disease).


Choledochal Cyst

In this condition, the main trunk (the common bile duct) of the biliary tree is structurally abnormal, probably form the time of birth. Eventually (usually by age 2 or 3 but sometimes not until adolescence or adulthood) the bile accumulates in the duct. It forms a sack or cyst which then presses on the bile duct and prevents bile form reaching the intestine. Bile backs up into the liver and the patient becomes jaundiced (yellow). Occasionally this accumulation of bile becomes infected, causing abdominal pain and fever. In some patients the cyst can be felt by the doctor examining the abdomen. In most patients the diagnosis can be confirmed by using sonic pictures (ultrasound) or by injecting a radioactive substance which gives an "image" of the abnormal duct (nuclear medicine). Treatment is surgical. The abnormal bile duct is removed and a piece of intestine used to replace it. In most cases, surgery permanently corrects the disease. Rarely, infection in the newly formes biliary tree recurs. If the condition is not correctly diagnosed the blockage of bile may result in scarring in the liver (cirrhosis).


Caroli's syndrome

Caroli's syndrome (intrahepatic ductal ectasia) is another rare congenital (from birth) disease. It is probably inherited. In this syndrome, the small branches of the biliary tree in the liver are abnormal. Small lakes alternate with narrowed segments of bile ducts, instead of the normal smooth contour. These abnormalities may be present throughout the liver, or limited to only a small area. If the bile duct becomes infected, the patient develops fever, abdominal pain and, rarely, jaundice. This complication may occur until middle age or may first appear in childhood. This disease is usually diagnosed by using radioisotopes to "image" the biliary tree and by injecting dye directly into the biliary tree. This may be done by inserting a needle through the skin into the liver (percutaneous transhepatic cholangiogram) or using a tube to pass dye through the intestine up into the bile duct (endoscopic retrograde cholangiography).


Congenital Hepatic Fibrosis

In patients with this condition, there is abnormal growth of fibrous tissue (scar) around the small branches of the bile ducts in the liver. As a result, the liver becomes enlarged and hard and blood can no longer flow freely through the liver. The spleen becomes enlarged and the blood must return to the heart through weak veins along the tube to the stomach (esophageal varices). These veins may burst and cause bleeding into the stomach and bowels. Patients with this condition are usually discovered in childhood, either because of the large liver or because of bleeding. The diagnosis is proven by liver biopsy and x-ray of blood vessels. There is no specific treatment for this condition but many patients require rerouting of blood from the intestines (shunt operation) to prevent more intestinal bleeding.


Polycystic Liver Disease

In some patients, large lakes (cysts) separate from the biliary tree form in the liver. In severe cases, the liver looks like a sponge. These cysts may cause pain, but do not affect liver function. In most patients, the kidneys are similarly affected with cysts, which may cause high blood pressure and kidney failure. The tendency to form cysts is probably present at birth in these patients, but usually the cysts do not enlarge and give problems until adulthood. This condition may be detected using ultrasound or CAT scan and x-rays of the kidney (intravenous pyelogram). Polycystic disease is inherited and once it has been detected in one member of a family, all the patient's relatives should be tested for it. There are two major categories of polycystic disease of the liver and kidney. In the more benign, the cysts are mostly in the liver and kidney function is near normal. These patients have a normal life expectancy. However those patients who have kidney damage need treatment for the equivalent of polycystic kidney disease.

All these conditions are rare and many people have never heard of them. They will probably be diagnosed with greater frequency in the future with the help of new tools such as ultrasonography. Several of these conditions are inherited. To help patients and their children, we need to know more about what causes these diseases and how to diagnose and treat them.