An arteriovenous (AV) fistula is an abnormal connection between an artery and a vein.
Small arteriovenous fistulas in your legs, arms, lungs, kidneys or brain are often asymptomatic and do not require treatment,other than monitoring by your doctor. Large arteriovenous fistulas may cause signs and symptoms like purplish, bulging veins, similar to varicose veins,Swelling in the arms or legs,hypotension ,fatigue and in severity Heart failure.
It may be congenital,surgically created for Hemodialysis,or may occur if you have a piercing injury, such as a gunshot or stab wound, on a part of your body where a vein and artery are side by side.
For small fistulas treatment is not required ,you will simply need to be monitored by your doctor and see if it closes on its own. If you require treatment, your doctor may recommend ultrasoundguided compression or Catheter embolization.