What is the liver, and what does it do?
The liver is the body’s second largest organ, located in the right side of the abdominal cavity below the diaphragm and above the right kidney and intestines. The liver helps the body in hundreds of ways.
All of the blood coming from the stomach and intestines passes through the liver through a large vein called the portal vein. The liver turns nutrients from the food we eat and chemicals from the medicines we take into forms that the rest of our bodies can use.
The liver helps clean the bloodstream of harmful substances and poisons.
The liver makes bile, which contains chemicals to help us digest the food we eat.
The liver helps control blood sugar and cholesterol levels
The liver makes the proteins that allow blood to clot normally.
What is portal hypertension?
Portal hypertension describes an increase in pressure within the portal vein, the vessel that carries blood from the organs of the digestive system (the intestines and the spleen) to the liver.
What happens to the liver and other organs in portal hypertension?
The increased blood pressure in the portal vein causes pressure in other blood vessels to increase as well. For instance, rising blood pressure can force blood to back up into the splenic vein, causing the spleen to swell. Pressure back into the veins of the intestines can cause diarrhea.
As the body senses the increased portal vein pressure, it tries to compensate by growing new veins that bypass the liver. These new veins, called varices, tend to be full of twists and turns, are much weaker than normal veins, and can bleed very easily. The varices tend to grow around the esophagus, spleen, stomach, and colon.
Because varices bypass the liver, toxins and nutrients that the liver would normally process can travel into the rest of the bloodstream.
What causes portal hypertension?
Portal hypertension results from a blockage in the portal vein before (“prehepatic”), within (“hepatic”), or past (“posthepatic”) the liver.
Prehepatic blockages, the most common cause of portal hypertension in children, stem from blood clots or narrowing of the portal vein before it reaches the liver. In response, the body grows varices that bypass the blockage but which, instead of relieving the pressure, lead to what is called “cavernous transformation of the portal vein.”
Cirrhosis is the most common cause of portal hypertension in adults, and the second most common in children. This progressive scarring of the liver is a result of long-term illness or damage to the liver caused by a wide range of conditions. In a child with cirrhosis, the liver’s soft, healthy tissue is gradually replaced with hard, nodular tissue that blocks the flow of blood through the portal vein.
Signs and symptoms
What are the symptoms of portal hypertension?
Portal hypertension itself usually causes no symptoms, though its complications can. For instance, varices can rupture and bleed easily, causing gastrointestinal bleeding evidenced by black, tarry stools or vomiting of blood. Fluid buildup, called ascites, can cause the abdomen to swell and enlarge. Some children feel vague discomfort in the upper left part of the abdomen, caused by enlargement of the spleen.
Because portal hypertension is itself often a complication of advanced liver disease, children with it may also experience symptoms of poor liver function. They may experience poor weight gain or weight loss, jaundice and confusion or forgetfulness due to the presence in the bloodstream of substances, such as toxins, that are normally filtered by the liver.
How is portal hypertension diagnosed?
Portal hypertension is often diagnosed through a combination of imaging and endoscopic studies. These techniques give physicians a comprehensive picture of the state of the portal vein and the organs and vessels connected to it.
For details, see tests.
How do you treat portal hypertension?
With portal hypertension, the main goal of therapy is to prevent further complications and reduce the risk of variceal bleeding while, ideally, reducing the pressure in the portal vein. This is accomplished through a combination of medication, endoscopic treatment (“banding” of varices), and surgical therapies (shunting of the blood flow in the portal venous system into the systemic circulation).
Because portal hypertension can be a late complication of liver disease, such as cirrhosis, it is important to try to manage the conditions that caused damage to the organ in the first place. Should the liver begin to fail, a liver transplant may become necessary.
For details, see treatment and care.
How can portal hypertension affect my child in the long term?
Because portal hypertension is typically a chronic condition, your child may have to seek care for it for the rest of his or her life. The Center for Childhood Liver Disease can help you and your child plan for the eventual transition from pediatric to adult care.