What is Portal Vein Thrombosis?
Portal Vein Thrombosis
is the condition associated with the obstruction of the blood flow in the hepatic portal vein (blood vessel draining blood from the gastrointestinal tract and spleen into the liver) which can cause portal hypertension (increased pressure) and reduction in the blood supplied to the liver. The obstruction of the blood flow is generally caused by a blood clot.
It is a rare condition with a reported incidence of 0.05-0.5% in autopsy studies. However, patients with cirrhosis of liver and acute liver disease have a higher incidence rate than others. About 25% patients with cirrhosis of liver have this condition.
What Causes Portal Vein Thrombosis?
Apart from other causes, certain critical medical conditions set forth this disease. Some times more than one cause can lead to this condition.
- Accidental trauma or physical injury.
- Clotting disorders like Polycythemia.
- Cirrhosis of liver.
- Formation of malignant tumors and cancerous mass in the pancreas or gastrointestinal tract.
- In newborns, infection of the umbilical cord stump can cause it.
- In children and infants, acute appendicitis have been found to cause it.
Symptoms of Portal Vein Obstruction
When the portal vein is obstructed by a clot the following symptoms are likely to surface.
- The narrowing and constriction of the portal vein causes the pressure in the portal vein to increase. This increased pressure causes the spleen to enlarge.
- The veins of the stomach and esophagus can become dilated, inflamed and twisted. These varices or varicose veins may rupture and bleed profusely.
- Vomiting blood is a common after step in this condition. Or it could pass through the digestive tract producing foul smelling black tarry stools called Melena.
- Intense abdominal pain is very common.
- Ascites or fluid retention in the abdomen is not common but is seen when the liver is damaged extensively due to the obstruction of the portal vein. Fluid may accumulate even when a large amount of fluids is administered through veins in order to treat the varices of the esophagus and stomach.
- Increased pressure in the portal vein may lead to the development of abnormally thin capillaries in the stomach which can cause stomach bleeding. This condition is also known as portal hypertensive gastropathy.
Treatment of Portal Vein Thrombosis
- To resolve the situation caused by an emergency blood clot, drugs which dissolve clots are administered.
- Drugs which act as anti coagulants and blood thinners are generally prescribed in patients who show symptoms of developing clots. Anti Coagulants such as Heparin are used to prevent future blood clots and obstructions of the portal vein.
- In newborns, where the infected umbilical cord causes the obstruction, it is generally treated with antibiotics.
- In children and infants, when acute appendicitis causes the blockage then it becomes essential to treat the inflamed appendix at once to make way for normal blood flow in the portal vein.
- Portal hypertension causing esophageal and stomach varices to bleed are treated by methods like rubber banding (Rubber bands are used to tie off tears and bleeding spots on the vein), Balloon Tamponade (air is introduced in the abdomen to increase surface tension in the bleeding vein and reduce the blood loss), making new connections in the blood vessels of the liver in case of cirrhosis of liver etc.
- Drugs such as beta blockers and nitrates reduce pressure of the portal vein and the occurrence of varices and bleeding. A drug known as Octreotide is given to bring down the blood flow directed to the liver reducing the resultant portal hypertension. This also helps to stop the bleeding.
- When all other treatment is ineffective, a surgery may be needed to create an alternate blood flow passage bypassing the liver. This can be done by the creation of a portacaval shunt. A connection is made between the portal vein which carries three fourths of the liver’s blood to the inferior vena cava (a vein that drains blood from the lower two thirds of the body) to let the blood flow bypassing the obstruction.