What Is Decompressive Craniectomy Surgery and Why Is It Done?

Relieving Pressure on the Brain Requires a Surgical Procedure

Question: What Is Decompressive Craniectomy Surgery and Why Is It Done?

Answer:

If your loved one has had a traumatic brain injury, one of the recommended treatments may be a decompressive craniotomy or craniectomy. This type of brain surgery is for patients who will die without intervention, and is done to relieve pressure on the brain.

Why Decompressive Craniectomy Is Done

The brain is unique in the human body because it is surrounded by bone.

With other types of injuries, such as a sprained ankle, an injury will swell without causing further damage to the ankle. The brain is encased in bone, so there is no room allowed for swelling, which can put tremendous pressure on the brain, and can even lead to death.

Because the brain is in an enclosed space, more swelling means more pressure builds and this can decrease blood flow.  

Imagine trying to blow up a balloon.  Early in the process it is easy to blow air into the balloon, but as it gets more and more full, it becomes more difficult to get more air into the balloon.  Now imagine someone has their hands on the balloon and they are squeezing the balloon as you try to blow air into it--nearly impossible, right?  The same is true of trying to get blood to the brain.  The building pressure is the squeezing hands on the balloon, and your breath is the heart working to pump blood to the brain.

 The pressure has to be decreased in order to get blood to the brain or the brain will starve for oxygen and eventually die.  In order to do that, we place a hole in the skull (balloon) to provide room for expansion.

The Decompressive Craniectomy 

A decompressive craniectomy surgery is a procedure that removes a section of the skull to relieve pressure on the brain.

It is an incision first made in the scalp, then through the bone using a special saw, which allows a piece of the skull to be removed and set aside (often frozen) to be replaced at a later date.  

Removing this section of the skull allows room for swelling, which relieves pressure and gives the brain a place to swell without causing more damage. For less severe injuries a ventriculostomy is typically done, which is less invasive than a craniectomy. A craniotomy makes the same hole in the skull to access the brain, but the piece is replaced during the procedure. 

It is important to remember that a decompressive craniectomy is done for severe brain injuries and swelling that cannot be controlled by other means including medications or a ventriculostomy. While the procedure can help prevent further damage, the initial injury and the subsequent swelling may still cause damage. Severe swelling may still result in long term deficits or even death, however, the chances of survival are improved by the procedure for most patients.

Craniotomy Versus Craniectomy

Sources:

Decompressive Craniectomy For Refractory Intracranial Hypertension After Traumatic Brain Injury. Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine. Accessed January 2010.http://ccforum.com/content/10/S1/P458

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