The arteries carry oxygenated blood to an organ, in this case the brain. The veins carry blood from the used again after the oxygen exchange on small vessels called capillary bed, took place. Arteriovenous malformations (formerly also called Angiomas) are inborn lesions which lack this exchange of oxygen. The blood flows through a short-circuit (nidus) directly from an artery to a vein.
Most often arteriovenous malformations (AVMs) become symptomatic by intracerebral hemorrhage. The risk of bleeding is about 2% per year. Other possible symptoms include seizures, headache and neurologic deficits. AVMs are frequently detected by coincidence on MRIs that have been done for another purpose.
If an AVM is diagnosed in a patient, preventive therapy should be discussed to eliminate the risk of bleeding. An interdisciplinary center with specialized equipment and personnel is a prerequisite to offer patients optimized treatment.
The different treatment methods include: microsurgical removal, endovascular embolization using a catheter and Radiation. Sometimes a combination of these therapies is necessary. The optimal therapy depends on the structural and anatomical conditions of the angioma one hand, and the symptoms on the other.