Oesophageal Varices protrude from the inner surface of the oesophagus and are usually the result of chronic liver disease. The position of the varices on the surface of the distal part of the oesophagus, or at its junction with the stomach, means that they are unsupported by other tissues and are at risk of rupturing when the blood pressure in the varices exceeds a certain level.
Varices can be detected by endoscopy but are often only diagnosed when they start to bleed. The amount of bleeding can range from a gentle oozing of blood to haemorrhaging that is difficult to control and can be life-threatening.
Causes of Oesophageal Varices
Oesophageal Varices generally form as the direct result of damage to the liver, which leads to an increase in blood pressure in the ‘portal vein’, which carries the main supply of blood from the bowel and spleen to the liver on its way back to the heart.
The rise in blood pressure in the portal vein is generally due to scarring and hardening of the liver tissue by cirrhosis, making it more difficult for the blood to flow through. This increased resistance causes the blood to find alternative routes to reach the heart, and new blood vessels open up to bypass the blockage.
These new routes involve veins that are not designed to carry this amount of blood. They are not very robust or elastic and become increasingly fragile as they continually enlarge and their walls become thinner in a bid to cope with the extra blood.
The original cause of restricted blood flow is not always obvious. Liver damage can be the result of a number of different factors including chronic alcohol abuse, infections, toxins, congestive heart failure and autoimmune disease.
In the West, alcohol is the most common cause of liver damage, though worldwide viral hepatitis and larval forms of parasitic schistosome worms, particularly common in the Middle East and South America, are responsible for 200 million cases.
Urgent need to treat BOV
Bleeding Oesophageal Varices (BOV) require urgent medical attention to prevent serious blood loss and complications. Not everyone with liver damage develops varices and not everyone with varices will bleed. In general, small varices rarely bleed bigger ones may bleed, but over time, small ones generally develop into bigger ones.
Approximately 90 per cent of patients with cirrhosis of the liver will develop Gastro-Oesophageal Varices over a period of about 10 years. In the West, Oesophageal Varices account for 5 – 10 per cent of all medical admissions with gastrointestinal bleeding.
Risk of death from BOV
The risk of death for those whose varices bleed for the first time has previously been put between 30 and 50 per cent. With recent therapies this risk has decreased to approximately 20 per cent. In some areas, the number of patients surviving one year after a bleed may be as low as 30 – 35 per cent, though this depends upon any associated liver damage as well as other complicating diseases.
Following an initial episode of BOV, the risk of it happening again is 60 to 80 per cent over a two year period with an approximate death rate of 20 per cent at each bleeding episode.