What is Hepatobiliary Disease?
Hepatobiliary disease is any disorder of the hepatobiliary system that impairs its normal function. The disease can range from minor infection or scarring to serious conditions such as cancer. The organs of the hepatobiliary system are the liver, gallbladder and bile ducts.
The liver is one of the largest organs of the human body and is situated in the upper right portion of your abdomen. It performs some of the body’s vital functions including:
- Production of bile juice
- Storing sugars in the form of glycogen
- Purifying blood from harmful substances
- Making proteins that help in blood clotting
The gallbladder is a small organ below the liver that stores a fluid called bile, necessary for fat digestion. The bile duct carries bile from the gallbladder to the small intestine.
The common risk factors that can cause hepatobiliary disease include:
- Advanced age
- Hormonal pills
- Inflammatory bowel disease
- Autoimmune diseases
- Excessive alcohol consumption
- Exposure to chemicals or toxins
- Exposure to infected blood (hepatitis infected person) by the sharing of contaminated needles, razors or blood transfusions
- Genetic diseases such as Wilson’s disease, Hemochromatosis and Alpha-1 antitrypsin deficiency
Types of Hepatobiliary Disease
Choledocholithiasis is the presence of gallstones in the bile duct, causing obstruction. Gallstones can occur in the gallbladder and migrate to the bile duct, or they can form in the bile duct itself.
Gallstones are usually composed of cholesterol or bile pigments. Lesser-known gallstones are made up of cholesterol and calcium salts. Cholesterol stones or pigment stones may be formed due to excess secretion of bilirubin (an orange-yellow pigment) or cholesterol, low secretion of bile salts or the presence of an infection.
Primary Sclerosing Cholangitis
Primary sclerosing cholangitis is a liver disease that causes narrowing of the bile duct. As the disease slowly progresses, bile builds up in the liver, damaging the cells. Scar tissue can spread throughout the liver, causing cirrhosis and liver failure. The cause of primary sclerosing cholangitis is unknown but is associated with inflammatory diseases such as inflammatory bowel disease, ulcerative colitis and Crohn’s disease.
Cirrhosis is severe scarring of the liver and poor liver function due to excessive exposure to alcohol or due to a viral infection. According to the National Institute of Health (NIH), people who regularly consume alcohol for more than 10 years can develop cirrhosis. Excess scar tissue is formed when your liver is exposed to the damaging factors for a long period of time, making it difficult to repair itself. A cirrhotic liver appears hard and shrunken.
Autoimmune Liver Diseases
The immune system protects the body by attacking and destroying foreign and harmful substances. However, in autoimmune liver diseases, the body’s immune system attacks its own liver (liver cells and bile duct cells), causing inflammation and liver damage. Example, autoimmune hepatitis.
Untreated autoimmune liver disease can progress into cirrhosis, liver failure and cancer.
Fatty Liver Disease
Fatty liver disease is a condition caused by excess fat buildup in the liver cells. It is most common in middle-aged people. Fatty liver disease is also called hepatic steatosis. Fatty liver is of two types:
- Non-alcoholic Fatty Liver: Buildup of fat in the liver is not associated with the consumption of alcohol.
- Alcoholic Fatty Liver: Buildup of fat in the liver is associated with excess alcohol consumption.
Simple fatty liver is an early stage of fatty liver disease and often not serious. Nonalcoholic Steatohepatitis (NASH) is an advanced stage that causes inflammation of the liver and damage to liver cells causing liver cirrhosis, liver cancer, ascites, and ultimately, liver failure.
Biliary dyskinesia or gallbladder dyskinesia is a motility disorder of the biliary system in which the bile does not drain out well from the gallbladder. Bile is a dark green to yellowish-brown fluid, secreted by the liver and stored in the gallbladder. A muscular valve called the sphincter of Oddi controls the movement of bile from the gallbladder (through the bile duct) to the small intestine. A metabolic disorder of the gallbladder or dysfunction of the sphincter of Oddi may disrupt the normal movement of bile causing it to backflow into the gallbladder.
Liver damage such as cirrhosis can cause high blood pressure within the portal venous system. Veins coming from the spleen, intestine, stomach and pancreas merge to form a large vein called the portal vein that further branches as it travels through the liver. Increase in the blood pressure causes the veins to swell (varices), rupture and bleed.
Jaundice is a condition that occurs when bilirubin, a yellow pigment produced by the breakdown of red blood cells in the liver, accumulates in the liver. It is a characterised by yellowing of the skin and sclera, the white regions of the eyes, and is caused by a viral infection, blocked bile ducts, liver diseases or certain medications.
Hepatitis is an inflammation of the liver tissue. Exposure to alcohol, toxins or drugs over a long period of time may result in hepatitis. It may also occur due to an autoimmune response in which antibodies (proteins) produced by your immune system damage your liver tissue, but most often, it is caused by a viral infection.
Gallbladder cancer is a rare disease that occurs when healthy cells acquire changes (mutations in their DNA) that make them divide uncontrollably and form a tumour. Cancer usually arises in the inner layers of the gallbladder and migrates to the nearby healthy tissues. It has 4 stages:
- Stage I: Cancerous cells are confined to inner layers
- Stage II: Tumour has invaded to the outer layers
- Stage III: Cancer has spread to nearby organs and lymph nodes
- Stage IV: Cancer has begun to spread to the distant organs of the body
Liver and Bile Duct Cancer
Liver cancer may begin as a mass of abnormal cells called a tumour. Benign tumours remain localised and do not spread to neighbouring tissues. Malignant tumours begin to spread into nearby tissues, lymph nodes or organs, disrupting their function. Most liver cancers are malignant and may lead to liver failure. Cholangiocarcinoma is cancer that begins in the connective tissue of the bile duct.
Liver failure occurs when a significant portion of your liver is non-functional and cannot be repaired. Various untreated liver diseases may lead to liver failure and cause secondary complications such as cerebral oedema, problems related to blood clotting and kidney failure. Most often, a liver transplant is the only option and is usually successful.
The symptoms vary depending on the type of hepatobiliary disease. Common symptoms include:
- Yellow skin and eyes
- Dark urine
- Clay-coloured stools
- Abdominal pain
- Nausea and vomiting
- Loss of appetite
- Swelling of abdomen and legs
- Itchy skin
- Blood clotting problems
Your doctor will assess your symptoms and may order:
- Liver Function Test: Determines the health of your liver, gallbladder and bile ducts.
- Cholecystokinin Hepatobiliary (CCK-HIDA) Scan: A small amount of radioactive dye and enzyme cholecystokinin is injected followed by a fatty meal. A nuclear medicine camera helps your doctor see how well bile is secreted from your gallbladder.
- Imaging Tests: Images of your liver, gallbladder and bile duct are obtained by performing an X-ray, CT scan or MRI.
- Transabdominal Ultrasound (TUS): Use of ultrasound to view the gallbladder or liver
- Endoscopic Retrograde Cholangiography (ERCP): An endoscope is inserted into your mouth and advanced towards the stomach and duodenum (first part of your small intestine). A dye is injected and X-ray images are taken to study your bile ducts.
- Biopsy: A small piece of suspected tissue is obtained and observed under the microscope for the presence of cancerous cells.
Treatment depends on the underlying cause and may include:
- Quitting smoking and alcohol consumption
- Diet modification usually involves a decrease in salt intake
- Weight loss program (obese people)
- Lithotripsy to manage gallbladder stones
- Medications to treat viral infection and other symptoms
- Medications to control autoimmunity
- Management of stress and diabetes
- Liver transplant in severe cases
Liver disease can be prevented by:
- Controlling diabetes
- Eating healthy
- Drinking alcohol in moderation
- Maintaining a healthy weight
- Avoiding contact with an infected person
- Preventing exposure to toxic chemicals