The walls of blood vessels are specially designed to withstand the constant pressure associated with the arterial system. In some instances, however, an aneurysm (or out-pouching) may develop. The cause of this abnormality is not known.

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.

Angiography

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.

MRA (Magnetic Resonance Angiography)

By applying the unique characteristics of MR, imaging techniques have been developed to allow for the visualization of blood vessels without the injection of radiopaque dye or use of x-ray. The procedure provides very good images that are often acceptable. In many cases, however, conventional angiography is required for evaluating intracranial aneurysm's since MRA does not provide the same degree clarity and accuracy.

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.

Types of Aneurysm's

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).