AVMs & Dural Arteriovenous Fistulas (dAVFs)

• Abnormal tangles (AVMs) or direct connections (fistulas) between arteries and veins, in which high-pressure arterial blood flows into veins not built to handle it
• May cause headaches, seizures, pulsatile ringing in the ear, or neurological symptoms — or may be silent until they bleed
• The main risk is hemorrhage into or around the brain, which can cause permanent injury
• Embolization delivers a liquid or coil material through a catheter to close off the abnormal vessels from the inside, and can shrink or completely cure many of these lesions
• Embolization may be the sole treatment, or may be combined with microsurgical removal or stereotactic radiosurgery depending on the size and location of the lesion
• Each case is reviewed individually, as the best strategy — and whether treatment is needed at all — depends on the specific architecture of the malformation