Treatment of Cerebral Aneurysms

An aneurysm is a sac, or outpouching, that develops on an artery in the brain. When the walls of an artery are weakened, the pulsing blood flow through the artery can cause the weak spot to expand and fill with blood, further thinning the arterial wall. Aneurysms may be caused by a genetic weakness in the artery or by degeneration of the artery caused by infection, injury, or hypertension.

Symptoms

By itself, an aneurysm may or may not cause symptoms, such as headache, muscle weakness, nausea, or numbness, depending on its size and its proximity to key structures, such as cranial nerves.

Over time, the wall of the sac may become so thin that it ruptures and blood fills the area around the brain. This condition, called subarachnoid hemorrhage, is a neurological emergency that is responsible for almost one fourth of all deaths due to nervous system disorders.

Diagnosis

Aneurysms can be identified and assessed with computed tomographic (CT) scanning, magnetic resonance imaging (MRI) scans, and four-vessel cerebral angiography. Further diagnostic information can be learned through cerebral blood flow study and lumbar punctures.

Treatment

The goal of treatment for an aneurysm is to prevent the sac from rupturing, usually by sealing it off from the rest of the circulatory system. Patients often are given medication, including painkillers, anticonvulsants, and antifibrinolytic agents, which are used to treat bleeding.

In addition to microsurgery, in which a tiny clip is used to seal off the neck of the aneurysm, an interventional neuroradiology technique called endovascular coiling is used as well. Coiling is a technique invented just over a decade ago. A catheter, or tube, is inserted in an artery in the groin and guided up through the blood vessels to the site of the aneurysm. Once in place, the catheter deploys several soft, flexible coils of platinum wire, called Guglielmi detachable coils (GDCs), into the sac. The blood around the coils clots and fills the aneurysm, preventing circulating blood from entering. A clot or other structure that blocks a blood vessel is called an embolus, and the creation of an embolus for therapeutic reasons is called embolization. Eventually, the blood vessel with the aneurysm will heal at the neck of the outpouching, and the GDCs are left in the patient. Especially complex aneurysms may be treated with a combination of endovascular and microsurgical techniques, or with a combination of coils and stenting.