by Dr. Manura Nanayakkara

Created on: November 19, 2010

Portal hypertension is a complication of liver cirrhosis. In addition it can be the result of various rare problems, such as Budd–Chiari syndrome.

What is portal venous system?

Portal system of veins carries blood from gut and spleen to the liver. It is called a portal system because it connects two capillary networks without directly connecting to the main venous supply. This portal venous supply carry nutrients and toxins absorbed from the gut into the liver. Upon entering to the liver toxic substances are quickly detoxified and nutrients are changed to more compatible formats. Then the end result is carried to the hepatic vein, which connects to the main systemic venous system. In addition there are many minute connections that connect portal system to the systemic veins, bypassing the liver.

What is portal hypertension?

Portal hypertension is the increased blood pressure inside the portal venous system. Since it is not directly connected to the main systemic circulation, it does not affect systemic blood pressure and vice versa.

In liver cirrhosis liver architecture is deranged. Due to this, the portal system is blocked by the obstruction of capillaries inside the liver. In addition portal hypertension can be caused by blockade of portal veins itself by blood clots (pre hepatic) or the blockade of hepatic veins (post hepatic), which carries blood from liver to the main circulation.  

What are the main symptoms?

1. Symptoms due to Porto systemic anastomosis
Due to increased pressure inside the portal venous system, various other minor routes are opened up that are connecting the portal system to systemic veins, bypassing the liver.

Esophageal varices and gastric bleeding

One of the most important anastomotic connections is situated inside the junction between esophagus and stomach. When the portal venous pressure rises, these minor connections are opened up which result in bulging of the said veins.

These varices are very delicate and they can easily rupture. This can cause severe internal gastric bleeding. This bleeding can be manifested as bloody vomiting and black tarry stools. If it is not stopped, it can result in life threatening blood loss. In addition this can precipitate more dangerous hepatic encephalopathy.

2. Hepatic encephalopathy

This is a dangerous complication of hepatic diseases characterized by confusion, altered sleep pattern and various other neurological phenomena. In addition it can cause coma and death. Hepatic encephalopathy is caused by various toxins that enter into the systemic veins, bypassing liver. These gut toxins mainly affect the brain. In addition it can be precipitated by a gastric bleeding.

3. Ascites (intra-abdominal fluid collection)

Increased portal pressure causes leaking out of fluid from the gut veins. This can result in fluid collecting inside the abdominal cavity. Ascites can cause various complications such as spontaneous bacterial peritonitis and breathing difficulty.

Summary

Portal hypertension is a dangerous complication of liver cirrhosis. It can cause stomach bleeding, hepatic encephalopathy (serious brain disorder) and abdominal fluid collection.

Sources

Clinical Medicine by Parveen Kumar and Michael Clark

Learn more about this author, Dr. Manura Nanayakkara.
Click here to send this author comments or questions.