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Cerebral Aneurysms

If you have been diagnosed with a cerebral aneurysm, chances are that you feel frightened. Most people think of an aneurysm as a ticking time bomb. In fact, this is rarely the case. About 3 percent of adults have a cerebral aneurysm, but most never have any symptoms at all.

What Is a Cerebral Aneurysm?
Risk Factors for Cerebral Aneurysm
Should My Cerebral Aneurysm Be Treated?
Surgical Treatments for Cerebral Aneurysm
Why Virginia Mason?

Patient Information:
Brain Aneurysm Foundation
Brain Aneurysm 101
Cerebrovascular and Stroke Conditions



What Is a Cerebral Aneurysm?

A cerebral aneurysm is a weak spot on an artery in the brain that balloons out in a pouch-like sac and fills with blood. If this sac of blood grows large enough, it can put pressure on a nerve or the brain tissue around it. 

Most aneurysms are small and cause no symptoms. They are often found during an MRI or CAT scan done for some other purpose.

If an aneurysm enlarges significantly, it may rupture. This results in it breaking open and spilling blood into the space around the brain. Fortunately, the risk of a rupture is very low (on average less than 1 percent a year) for most aneurysms.

When an aneurysm ruptures, it is described as a “thunderclap” headache – the worst headache someone has ever experienced. A ruptured aneurysm is a medical emergency requiring immediate transportation to an emergency room and a neurosurgical evaluation.

Risk Factors for Cerebral Aneurysm

Women are 50 percent more likely than men to develop an aneurysm, due to a possible connection with female hormones.

Other risk factors include personal habits or health conditions that stress or weaken artery walls.

These include:

  • Smoking – 75 percent of patients with ruptured aneurysms are cigarette smokers
  • Uncontrolled high blood pressure
  • Use of stimulant drugs, such as cocaine and methamphetamine
  • Heavy use of alcohol, typically defined as seven drinks or more per week
  • Polycystic kidney disease
  • Ehlers-Danlos syndrome
  • Marfan’s syndrome
  • Fibromuscular dysplasia

Family history is also a risk factor. If two first-degree relatives in your family have a history of a cerebral aneurysm, you should be screened with an imaging study. Your primary care provider can initiate a screening for you.

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Should My Cerebral Aneurysm Be Treated? 

Most aneurysms are not treated, but once discovered, are screened periodically to make sure they are not growing.

The decision to treat or not treat an aneurysm is based on calculating the risk that an aneurysm may rupture during a patient’s lifetime. Factors used to determine the risk of rupture include:

  • Location — an aneurysm in the back of the brain is at higher risk for rupturing than an aneurysm at the front of the brain
  • The size and shape of the aneurysm
  • If the patient has a history of a previous aneurysm rupture
  • A person’s age and overall health

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Surgical Treatments for Cerebral Aneurysms 

Brain Aneurysm Detection and Treatment Guide

The goal of treating an aneurysm is to prevent it from filling with blood so it cannot rupture. Two different surgical approaches are effective in treating cerebral aneurysms: Microsurgical clipping and an endovascular coiling.

Both are excellent treatment options for cerebral aneurysms. Your cerebrovascular specialist will help you make the right choice for you.

If you have microsurgical clipping:

  • You will be under general anesthesia
  • A tiny window of bone will be opened in the skull to allow microsurgical access to the aneurysm
  • A titanium clip will be placed on the outside of the aneurysm to prevent circulating blood from going into it.
  • The window of bone is then replaced

After this procedure, you will be observed in the hospital for two to three days.  You will likely resume light activities after two weeks at home, and return to work within three to four weeks.

Microsurgical clipping is the most time-tested and durable treatment for cerebral aneurysms. It has a very low rate of recurrence and a low rate of complications. 

If you have the endovascular approach:

  • You will likely be under general anesthesia, though light sedation is sometimes appropriate
  • A small catheter is threaded through the femoral artery in the groin and up into the aneurysm
  • Several tiny platinum “coils” are then used to fill the aneurysm from the inside to prevent blood from entering it
  • The catheter is then removed through the femoral artery

Most people who have this procedure are discharged from the hospital the next day. Light activity is recommended for three days to allow the incision in the femoral artery to heal.

The recovery from this procedure is quicker than microsurgical clipping, but the treatment is slightly less durable. With this treatment, you will be periodically screened to make sure the aneurysm does not recur.

Why Virginia Mason? 

At Virginia Mason, we do everything possible to make sure you feel comfortable and supported. Our cerebrovascular surgeons, interventional specialists, radiologists, technicians, nursing staff and social workers are all highly experienced and experts in their fields.

Our facilities are well equipped for even the most complex procedures, and our patient rooms and waiting areas are designed to be calm and comfortable for you and your family. For more information about care for carotid stenosis, call (206) 223-7525.

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