Fibrosis is the medical term for scarring. In chronic liver disease, there is typically some type of chronic low level inflammation and injury that affects the liver over the course of years. As this inflammation progresses it causes fibrosis, or scar formation, within the liver. Fibrosis can be assessed by several different methods. Currently the gold standard test for assessment of fibrosis is the liver biopsy, during which a small hollow bore needle is introduced into the liver and a small sliver of liver tissue is removed using the needle. The tissue is then sent to a pathologist who analyzes the tissue under the microscope. There is a staging system for fibrosis that ranges from stage 1 to stage 4. As an injured liver progresses from one stage to the next, scar tissue slowly replaces the normal functioning liver tissue. Stage 4 is considered cirrhosis. Sometimes, cirrhosis can also be diagnosed with ultrasound, CT scan, MRI, or a new imaging technology called Fibroscan.
In cirrhosis, as normal liver tissue is replaced by fibrosis, the ability of the liver to perform its usual functions diminishes. Changes include, but are not limited to, alterations in blood flow through the liver, decreased ability to synthesize proteins and other substances, decreased ability to process drugs and toxins, and decreased immune system function. As the liver continues to lose function over the course of years and sometimes decades, the failure of multiple liver functions ultimately can lead to end stage liver disease.
The portal vein carries blood from the stomach, intestines, spleen, and pancreas to the liver. In cirrhosis, the fibrosis within the liver alters blood flow by increasing the resistance of blood flow through the liver. This results in an increase in pressure within the portal vein called portal hypertension. The development of portal hypertension can lead to a number of other complications including ascites, edema, encephalopathy, varices, splenomegaly.
Cirrhosis and portal hypertension can lead to the development of fluid retention in the body. When fluid collects in the superficial tissues of our bodies, it is caused edema. This most commonly occurs in the feet and lower extremities. The finding of lower extremity edema is easily detected by physical examination. When the fluid collects within our intra-abdominal cavity this accumulation of fluid is caused ascites. When there is a large volume of ascites, it can be detected by physical exam and can be detected by an increase in abdominal girth. When there are smaller volumes of ascites, it is sometimes only detected by ultrasound examination. People who have ascites have a risk of developing an infection of the ascites fluid called spontaneous bacterial peritonitis (SBP). Symptoms of this may include abdominal pain and fever. If this occurs, call your physician immediately and consider going to the emergency room. SBP can be a potentially life threatening infection.
As a cirrhotic liver develops progressively diminishing function, it is less and less able to remove toxins from the blood. As a result, certain toxins can build up in the blood stream. Some toxins can affect the brain and result in a condition called hepatic encephalopathy. Symptoms can include personality changes, irritability, sleep pattern changes, difficulty concentration, confusion, somnolence, and at its most severe, coma. Even with mild encephalopathy, people can be impaired enough to make driving dangerous.
With portal hypertension, the elevated pressure in the portal vein can be transmitted to other connecting blood vessels. As this pressure builds, the other blood vessels can become more engorged. Blood vessels in the esophagus, stomach, or both can be involved and are called esophageal or gastric varices. These enlarged blood vessels can become enlarged enough that the rupture, resulting in significant bleeding within the esophagus or stomach. Signs that this may have occurred include vomiting blood, passing black colored or red colored bowel movements. When this occurs, it is a medical emergency and you should call your physician immediately and consider calling 911. All people diagnosed with cirrhosis should have an endoscopy (a procedure to look into the esophagus and stomach) to screen for varices. If varices are present and of a certain size, medications can be prescribed to reduce the risk of bleeding from ruptured varices.
Just as portal hypertension can cause elevations in the pressure of blood vessels in the esophagus and stomach (esophageal and gastric varices) the increase in portal vein pressure can also be transmitted into the spleen. This increase in pressure can cause the spleen to swell and enlarge. This is called splenomegaly. Splenomegaly in turn, can cause this organ to retain white blood cells and platelets, reducing the number of these cells in the blood.
People with cirrhosis are at a higher risk of developing liver cancer, called hepatocellular carcinoma. Due to this elevated risk, people who have cirrhosis should be screened for liver cancer every 6-12 months with a combination of blood work, ultrasound, or CT scan. Early detection of liver cancer improves treatment options and outcomes.