Clinical Information An aneurysm is a sac-like protrusion of an artery caused by a weakened area within the vessel wall. If a cerebral (brain) aneurysm ruptures, the escaping blood within the brain may cause severe neurologic complications or death. A person who has a ruptured cerebral aneurysm may complain of the sudden onset of "the worst headache of my life." The most common interventional neuroradiology procedures include: Aneurysm coiling. Embolization of arteriovenous malformations and fistulea. Tumor embolization. Stroke intervention (thrombolysis and angioplasty). Vasospasm therapy. Temporary vessel occlusion. These disorders are typically treated by specialists such as: Interventional Neuroradiologist Neurosurgeon Interventional Radiologist Interventional Cardiologist A small number of these specialists have acquired the requisite additional training to be able to safely perform interventions in the neurovasculature. It is estimated that only about 800 specialists worldwide are trained to perform these interventional therapies. MicroVention has developed technologies to address the aneurysm coiling procedure. Below is a diagram of the Circle of Willis. Most brain aneurysms occur in or near this area.