FAQ on Extra Hepatic Portal Venous Obstruction (EHPVO)
1. What is EHPVO?
EHPVO is a condition in which there is a block of the major vessel that supplies blood to the liver i.e. the portal vein. This vein carries all absorbed nutrients from intestines to liver for storage and further metabolism. It accounts for major (80%) of blood supply to liver. Any block in this vein especially in the portion of the vein located outside the liver causes a condition called as EHPVO.
2. What causes EHPVO?
EHPVO or the block in the portal vein may be caused by:
- Infections: in infants – umbilical sepsis or umbilical catheterisation is a major cause of EHPVO in infants. Intra abdominal sepsis, appendicitis and peritonitis are other causes especially in elder children.
- Congenital agenesis or Atresia-meaning absence of portal vein or small portal vein since birth
- Hypercoagulable states: certain genetic conditions which can make the blood thicker than usual – like Protein C, Protein S deficiency, Factor V Leiden deficiency, polycythemia Vera
- Idiopathic: cause not known.
3. How does a patient of EHPVO present?
The most common presentation of EHPVO is vomiting out blood or what is called as hematemesis.
Since the portal vein is blocked, a lot of blood is being carried by it from the intestine to the liver, there is formation of newer veins around the blocked portal veins -"portal cavernoma"- and also bypassing of the blood to the veins in the esophagus and stomach called varices. This helps to decompress the high pressure in the portal veins. These varices are fragile and when pressure builds up rupture easily which results in bloody vomits. These dilated veins are called varices.
The blood most commonly originates from the oesophageal varices but can also be because of varices in the stomach called gastric varices. Varices can also occur around the rectum and anus leading to rectal bleeding of fresh blood though uncommon.
Apart from fresh bleeding, slow bleeding from the digestive tract can lead to black sticky tarry stools called malena. This slow indolent bleeding can cause significant blood loss and anaemia.
The patient may also have abdominal distension which, when examined by the doctor is mainly due to an enlarged spleen. Or sometimes can be due to fluid. Sometimes, EHPVO can manifest as only an enlarged spleen without bleeding. This enlarged spleen can cause decrease in number of platelets in the blood. Platelets normally help in clotting of blood. Reduced platelets thus reduce the wound healing and increase blood loss with trauma.
Liver function is usually unaffected in patients with EHPVO. However, in some cases EHPVO can cause bile duct obstruction and jaundice. This may require surgical treatment
4. How can we diagnose EHPVO?
The easiest and most convenient way of diagnosing EHPVO is abdominal ultrasound with colour Doppler of the portal venous system. This will tell us about the patency of the portal vein and blood flow direction and velocity. It can also pick up congenital abnormalities, portal cavernoma and degree of spleen enlargement
Endoscopy can be done to evaluate varices, their potential to bleed, and to treat them. Proctoscopy can be done to evaluate rectal varices.
5. How do we manage a case of EHPVO?
The major concern in a case of EHPVO is bleeding from the digestive tract due to varices. Hence the cornerstone of management of EHPVO is to control this bleeding.
Endotherapy i.e. therapy through the endoscope is the choice of therapy today. It is of two types-
- Sclerotherapy: where a drug is injected into the dilated veins which cause sclerosis or drying up of veins.
- Band ligation: in this the dilated veins are ligated i.e. tied with the help of a special type of rubber band. This also causes the veins to shrivel and shed away.
Surgery can be considered if there is no response after the endotherapy or if the child is not growing well or tolerating endotherapy or has no access to therapy
6. What are the long term effects of EHPVO?
EHPVO can cause major disturbances in the growth of the child. The child may not gain adequate height. This is an indication for surgery.
It can also cause significant anaemia due to bleeding. Contact sports need to be avoided in patients with EHPVO.
Important articles on EHPVO:
Management of extra hepatic portal venous obstruction (EHPVO): current strategies.
Poddar U, Borkar V. Tropical Gastroenterology 2011;32(2):94–102.
Approach to a child with upper gastrointestinal bleeding.
Surgical guidelines for the management of extra-hepatic portal vein obstruction.
. Growth assessment in children with extra-hepatic portal vein obstruction and portal hypertension.
Extrahepatic portal vein obstruction.
Liver and spleen stiffness in patients with extrahepatic portal vein obstruction.