December 23, 2014

Fatty Liver


Explore this section to learn more about fatty liver, what effect it has upon the liver's condition and ability to function, and how it can lead to more serious liver disease.

What is fatty liver?
Fatty liver is just what its name suggests: the build-up of excess fat in the liver cells. It is normal for your liver to contain some fat. But if fat accounts for more than 10% of your liver’s weight, then you have fatty liverand you may develop more serious complications.

Fatty liver may cause no damage, but sometimes the excess fat leads to inflammation of the liver. This condition, called steatohepatitis, does cause liver damage. Sometimes, inflammation from a fatty liver is linked to alcohol abuse; this is known as alcoholic steatohepatitis. Otherwise the condition is called nonalcoholic steatohepatitis, or NASH.

An inflamed liver may become scarred and hardened over time. This condition, called cirrhosis , is serious and often leads to liver failure.
NASH is one of the top three leading causes of cirrhosis.
What are the symptoms of fatty liver?
A fatty liver produces no symptoms on its own, so people often learn about their fatty liver when they have medical tests for other reasons. NASH can damage your liver for years or even decades without causing any symptoms. If the disease gets worse, you may experience fatigue, weight loss, abdominal discomfort, weakness and confusion.
What causes fatty liver?
Eating excess calories causes fat to build up in the liver. When the liver does not process and break down fats as it normally should, too much fat will accumulate. People tend to develop fatty liver if they have certain other conditions, such as obesity, diabetes, or high triglycerides. Alcohol abuse, rapid weight loss and malnutrition may also lead to fatty liver. However, some people develop fatty liver even if they have none of these conditions – so everyone should know about it.
How is fatty liver diagnosed?
Your doctor may see something unusual in your blood test or notice that your liver is slightly enlarged during a routine checkup. These could be signs of a fatty liver. To make sure you don’t have another liver disease, your doctor may ask for more blood tests, an ultrasound, a CT scan or an MRI. If other diseases are ruled out, you may be diagnosed with NASH. The only way to know for sure is to get a liver biopsy. Your doctor will remove a sample of liver tissue with a needle and check it under a microscope.
How is fatty liver treated?
There are no medical or surgical treatments for fatty liver, but there are some steps you can take that may help prevent or reverse some of the damage. In general, if you have fatty liver, and in particular if you have NASH, you should:
  • Lose weight – safely! That usually means losing no more than one or two pounds a week.
  • Lower your triglycerides through diet, medication or both
  • Avoid alcohol
  • Control your diabetes, if you have it
  • Eat a balanced, healthy diet
  • Increase your physical activity
  • Get regular checkups from a doctor who specializes in liver care
If I’ve been diagnosed with fatty liver, what questions should I ask my doctor?
  • “What is the likely cause of my fatty liver?”
  • “Do I have NASH? If not, how likely am I to develop NASH?”
  • “Do I have cirrhosis? If not, how likely am I to develop cirrhosis?”
  • “Do I need to lose weight? How can I do so safely?”
  • “Should I be taking any medication to control my triglyceride levels?”
  • “What medications or other substances should I avoid to protect my liver?”
Who is at risk for fatty liver?
Most (but not all) fatty liver patients are middle-aged and overweight. The risk factors most commonly linked to fatty liver disease are:
  • Overweight (body mass index of 25-30)
  • Obesity (body mass index above 30)
  • Diabetes
  • Elevated triglyceride levels
What is the best way to prevent fatty liver?
The best way to reduce your risk of developing fatty liver is to maintain a healthy weight and normal triglyceride levels. You should also avoid excess alcohol and other substances that could harm your liver.
Adapted from: American Liver Foundation

Budd-Chiari Syndrome


Budd-Chiari syndrome is caused by blood clots that completely or partially block the large veins that carry blood from the liver (hepatic veins) into the inferior vena cava.

  • Some people have no symptoms, but others experience fatigue, abdominal pain, nausea, and jaundice.
  • Fluid may accumulate in the abdomen, the spleen may enlarge, and sometimes severe bleeding occurs in the esophagus.
  • Doppler ultrasonography can detect narrowed or blocked veins.
  • Drugs may be used to dissolve or decrease the size of the clot, or a connection may be made between veins to allow blood to bypass the liver.

Budd-Chiari syndrome usually occurs when a clot narrows or blocks the hepatic veins.

Because blood flow out of the liver is impeded, blood accumulates in the liver, causing it to enlarge. The spleen may also enlarge. The backup of blood (congestion) in the hepatic veins causes blood pressure in the portal vein to increase. This increased pressure, called portal hypertension, can result in dilated, twisted (varicose) veins in the esophagus (esophageal varices). Portal hypertension, plus the engorged and damaged liver, leads to fluid accumulating in the abdomen, a condition termed ascites. The kidneys contribute to the problem by causing salt and water to be retained.

The clot may extend to also block the inferior vena cava (the large vein that carries blood from the lower parts of the body, including the liver, to the heart). Varicose veins in the abdomen near the skin's surface may develop and become visible.

Eventually, severe scarring of the liver (cirrhosis) occurs.

Causes

Usually, the cause is a disorder that makes blood more likely to clot, such as the following:

  • Excess red cells (polycythemia)
  • Sickle cell disease
  • Inflammatory bowel disease
  • Connective tissue disorders
  • Injury

Sometimes Budd-Chiari syndrome begins suddenly and rather severely, typically during pregnancy. During pregnancy, the blood normally coagulates more readily. In some women, a blood clotting disorder may first become apparent during pregnancy. Other causes include disorders that develop near the hepatic veins, such as parasitic infections and liver or kidney tumors that press on or invade the veins. In Asia and South Africa, the cause is commonly a membrane (web) that blocks the inferior vena cava. Often, the cause is unknown.

Symptoms

Symptoms vary somewhat depending on whether they appear suddenly or develop more slowly.

Usually, symptoms develop gradually over weeks or months. Fatigue is common. The enlarged liver becomes tender, and people have abdominal pain.

Fluid may accumulate in the legs, causing swelling (edema), or in the abdomen, causing ascites. Varicose veins in the esophagus can rupture and bleed, sometimes profusely. People may vomit blood. Such bleeding is a medical emergency.

If cirrhosis develops, it can lead to liver failure with deterioration of brain function (hepatic encephalopathy), resulting in confusion and even coma

Sometimes symptoms begin suddenly, such as hepatic vein thrombosis during pregnancy. In this case, people feel tired, and the liver is enlarged and tender. Abdominal pain occurs in the upper abdomen. Additional symptoms include vomiting and a yellow discoloration of the skin and whites of the eyes—a condition called jaundice. Liver failure infrequently develops.

Diagnosis

Doctors suspect the Budd-Chiari syndrome in people with either of the following:

  • An enlarged liver, ascites, liver failure, or cirrhosis when there is no obvious cause, even after testing
  • Abnormal results of blood tests done to evaluate liver function plus conditions that increase the risk of blood clots

If results of liver function tests are abnormal, an imaging test, typically Doppler ultrasonography, is done. If results are unclear, magnetic resonance imaging of blood vessels (magnetic resonance angiography) or computed tomography (CT) is done.

If surgery is planned, venography is necessary. For this procedure, x-rays of the veins are taken after a radiopaque dye (which is visible on x-rays) is injected into a vein in the groin.

A liver biopsy may be done to confirm the diagnosis and identify if cirrhosis has developed.

Prognosis

When the vein remains completely blocked, most people, if untreated, die of liver failure within 3 years. When the blockage is incomplete, life expectancy is longer but varies.

Treatment

Treatment depends on how rapidly the disorder has developed and how severe it is.

When symptoms begin suddenly and the cause is a clot, fibrinolytic (thrombolytic) drugs, which dissolve clots, help. On a more long-term basis, anticoagulant drugs prevent clots from enlarging or recurring.

If a vein is narrowed or blocked by a web, angioplasty may be done to widen it. For this procedure (called percutaneous transluminal angioplasty), a catheter with a deflated balloon at its tip is inserted through the skin into a blood vessel (such as the femoral vein in the groin) and threaded to the blocked vein. The balloon is inflated, widening the vein. A wire mesh tube (stent) is then inserted and left in place to keep the vein open.

Another solution is to create an alternate route for blood flow, bypassing the liver. This procedure, called transjugular intrahepatic portal-systemic shunting (TIPS), reduces pressure in the portal vein. For the procedure, a local anesthetic is used to numb the neck, and a catheter with a cutting needle is inserted into a vein in the neck (jugular vein). The catheter is threaded through the inferior vena cava to the hepatic vein. The needle is used to create a connection (called a shunt) between two veins, usually a branch of the hepatic vein and the portal vein, so that blood can bypass the liver. Then, an expandable metal tube (stent) is threaded to and placed in the shunt to keep it open. The shunt enables blood to bypass the liver, flowing from the portal vein (which normally brings blood to the liver) directly to the hepatic veins (which drain blood away from the liver). The blood returns to the heart through the inferior vena cava. However, such shunts increase the risk of hepatic encephalopathy (deterioration of brain function due to liver dysfunction). Also, shunts occasionally become blocked, especially in people who have a tendency to form blood clots.

Liver transplantation can be life-saving, particularly for people with severe liver failure.

Problems resulting from the disorder are also treated:

  • Bleeding from varicose veins in the esophagus: Several techniques can be used to stop the bleeding. Usually, rubber bands are inserted through a flexible viewing tube (endoscope), placed through the mouth into the esophagus. The bands are used to tie off the varicose veins (termed ligation).
  • Fluid accumulation in the abdomen: A low-salt (sodium) diet and diuretics can help prevent too much fluid from accumulating in the abdomen.

Most people need to take anticoagulants indefinitely to prevent new blockages from developing.
Adapted from: Merck & Co., Inc.