Arteriovenous Malformation (AVM):An AVM is a congenital condition affecting the blood vessels in the brain, brainstem, or spinal cord, identified by a tangled network of abnormal arteries and veins linked by one or more fistulas (unusual connections). An AVM lacks its own capillary bed, allowing for high-pressure, high-flow shunting of blood directly from the arterial to the venous side. This shunting results in increased pressure (hypertension) in the arteries supplying the AVM and in the nearby brain regions they normally nourish.AVMs typically manifest symptoms before the age of 40. Common issues include bleeding, seizures, headaches, and neurological impairments such as difficulties with speech, memory, or vision. The occurrence rate of these symptoms varies between 30-82% in different studies, and AVMs account for 2% of all strokes.There are three primary treatment options for AVMs:1. **Surgical Removal**: This is the most traditional and well-known approach. The procedure involves delineating the malformation's boundaries, tying off or clipping the feeding arterial vessels, sealing the draining veins, and excising or obliterating the nidus (the core) of the AVM.2. **Endovascular Embolization**: This method involves occluding the AVM's blood vessels using non-surgical techniques. Catheters deliver agents such as permanent balloons, thrombosing coils, sclerosing drugs, and fast-acting embolization glue to block the vessels, often as a precursor to surgery.3. **Radiosurgery**: This technique targets the AVM with concentrated radiation beams to damage and clot the AVM. The effects of radiosurgery take weeks to months to fully develop. A potential risk is damage to surrounding nervous tissue, including normal brain or spinal cord tissue. Therefore, radiosurgery is typically reserved for AVMs that are small (less than 3 cm in diameter), located deep within critical brain regions, or have numerous feeder arteries making embolization impractical.Most individuals with AVMs (approximately 80% or more) do not experience any issues. However, hemorrhaging AVMs can lead to severe neurological complications and, in some cases, can be fatal.
