Allegheny Health Network
Find a
Request An Appointment Login to
News Classes &
Call 412.Doctors

Cerebral aneurysm

A cerebral aneurysm is an abnormal bulge in an artery in your brain caused by weakening or thinning of the wall of the artery. Most aneurysms go undetected until they begin to bleed – causing a subarachnoid hemorrhage  – or an aneurysm can grow to a size that pushes on a nerve or the surrounding brain. Bleeding from a brain aneurysm is a life-threatening emergency, requiring complex medical and surgical skills to increase the chances of recovery.


  • Sudden severe headache
  • Nausea
  • Vomiting
  • Visual disturbance
  • Loss of consciousness


Computed tomography scan (CT or CAT scan) uses a combination of X-rays and computer technology to produce cross-sectional images (often called slices), both horizontally and vertically, of the body. A CT scan is more detailed than general X-rays and shows detailed images of any part of the body, including the bones, muscles, fat and organs.

Magnetic resonance imaging (MRI) uses large magnets attached to a computer to produce detailed images of organs and structures within the body.

Echocardiogram (echo) evaluates the structure and function of the heart by using sound waves recorded on an electronic sensor that produce a moving picture of the heart and heart valves.

Arteriogram (angiogram) is an X-ray image of the blood vessels used to evaluate the aneurysm. A dye (contrast) is injected through a thin flexible tube placed in an artery, and the dye makes the blood vessels visible on the X-ray.

Ultrasound uses high-frequency sound waves and a computer to create images of blood vessels, tissues, and organs. It is used to view internal organs as they function and to assess blood flow through various vessels.


Microsurgical clipping is performed to clip the aneurysm and seal off the weakened part of the artery. First, the surgeon performs a craniotomy, which means a window is created in the skull to find the aneurysm. Once the aneurysm is exposed and dissected, a small, hinged aneurysm clip is placed on the neck of the aneurysm. This prevents the aneurysm from bleeding again.

Coil embolization involves placing small platinum coils into the bulge of the aneurysm to seal it off while preserving normal blood flow of the artery. This procedure does not require a craniotomy or a head incision because it is a minimally invasive procedure performed under general anesthesia. During the procedure, a small tube (catheter) is placed through an artery in your groin, and it is threaded to the arteries in your neck. Another smaller tube is threaded through the first one, and the physician delivers small platinum coils to the aneurysm through the second tube. These coils block off the ballooned part of the artery, and the normal opening of the artery is left clear.