This interruption of the normal vessel wall is frequently thin and weak and subject to bursting or leaking. When this happens, the patient may experience headache, nausea, vomiting, double vision, sensitivity to light, neck pain or stiffness, weakness, paralysis, memory loss, coma or death.

CT scan showing aneurysm (large arrow) and blood from a recent hemorrhage (small arrows - light areas).

Arteriogram - Lateral view showing a posterior communicating artery aneurysm.

An angiogram is a procedure where a radiopaque dye is injected into the arteries. It casts a white shadow on the x-ray film that represents a cast of the inside of the blood vessels. The portion of the study that examines the arteries is often referred to as an arteriogram. This is performed to determine the exact size, shape and location of the aneurysm.

Surgical Treatment

In order to prevent the aneurysm from hemorrhaging (bleeding) or re-bleeding, the neurosurgeon places a clip across the neck of the aneurysm. This surgery is performed with the aid of a surgical microscope.

Artists rendering of a clip applied across the neck of an aneurysm (the aneurysm has deflated)

Arteriogram showing an aneurysm on the posterior communicating artery.

Arteriogram showing clip placed across the neck of the aneurysm. The aneurysm no longer fills with blood.

Types of Aneurysms

The difficulty of this procedure depends upon the type of aneurysm and its location. A "saccular" aneurysm with a narrow neck is less difficult to clip than one with a broad neck. The most difficult aneurysm to manage is the "fusiform" type. Also difficult to manage is the "giant" aneurysm (2.5cm or greater).

Saccular aneurysm with narrow neck

Saccular aneurysm with broad neck

Fusiform aneurysm

Vasospasm

When an aneurysm hemorrhages, the blood that is present in the vicinity will trigger vasospasm or shrinking and narrowing of the vessels. This is a natural process which the body uses to control the bleeding. Vasospasm, however, can seriously reduce the blood supply to various areas of the brain causing additional symptoms. This can happen up to 3 weeks after the initial bleeding.

Vasospasm constricts the vessels and reduces flow to parts of the brain.

Embolization

In some instances, when it is not possible to surgically clip an aneurysm because of its location or when the patient cannot undergo a surgical procedure because of other risk factors, embolization is an option. The procedure used most commonly involves the insertion of a "coil" of wire into the aneurysm. The coil is delivered to the aneurysm through catheters (tubes) placed in the arteries. The procedure does not involve an open craniotomy and can be done under local anesthesia. Other methods of embolization include balloons and rapidly solidifying polymers. Surgical clipping remains the procedure of choice whenever it is possible because of its known effectiveness in permanently closing off the aneurysm to the flow of blood.

Early Intervention

Blood relatives of patients with aneurysms should be evaluated by a neurosurgeon since this condition is hereditary. Early treatment can help to prevent complications.