An arteriovenous fistula is a disruption of the normal blood flow pattern. Normally, oxygenated blood flows to the tissuethrough arteries and capillaries.
The main symptoms of arteriovenous fistulas near the surface of the skin are bulging and discolored veins. In some cases, the bulging veins can be mistaken for varicoseveins.
Treatment: Small arteriovenous fistulas can be corrected by surgery. Fistulas in the brain or eye are very difficult to treat. If surgery is not possible or if it is difficult then injection therapy may be used.