Arteriovenous malformations (AVMs) are congenital vascular abnormalities. They are made of an abnormal number of blood vessels which are of abnormal structure. The blood vessels in an AVM directly shunt blood from arterial system to the venous system, without any intervening capillaries to steadily dampen the blood pressure.
AVMs, have a risk of rupture, which can lead to brain haemorrhage and stroke. Other effects can include vascular headache and seizures (epilepsy).
Treatment options include observation (no treatment), endovascular embolization (where ‘glue’ squirted into the AVM through a catheter inserted through a blood vessel in the groin), craniotomy and surgical removal (i.e. brain surgery), and stereotactic radiosurgery (SRS).