What Is a Craniectomy?

Medically Reviewed by Sabrina Felson, MD on May 04, 2023
3 min read

A craniectomy is a type of brain surgery in which doctors remove a section of a person’s skull. Doctors do this surgery to ease pressure on the brain that happens because of swelling or bleeding. They leave the skull open until the pressure goes down, at which point they close the opening in the skull.

Craniectomies are only performed when a person is in critical condition. They can reduce the risk of brain damage after an injury or stroke.

The brain is a delicate organ that has multiple layers of protection. The most obvious layer is your skull. The bones that make up your skull prevent most injuries to the brain. Inside the skull, the brain is wrapped in a tissue sac called the meninges. There is fluid in the meninges called cerebrospinal build, which adds a final layer of protection. ‌

If the brain swells or there is an increase in the fluid inside your skull, intracranial pressure also increases. Pressure can injure the tissue of the brain and cause lasting brain damage. There are several causes for increased pressure on the brain, including:

There are several different treatment options for pressure on the brain, including medication to reduce swelling or a procedure to drain the fluid. In some cases, a person needs a craniectomy to release the pressure and reduce the risk of brain damage.

Intracranial pressure is a serious issue that needs immediate medical attention. There are symptoms that can warn you about pressure on your brain. Many of them can be mistaken with other health issues. If you have more than one of these symptoms, or if the symptoms get worse instead of better, call your doctor right away:

  • Headache
  • Confusion
  • Blurred vision
  • Nausea and vomiting
  • Unexplained behavior changes
  • Shallow breathing
  • Unexplained weakness
  • Difficulty moving or talking
  • Fatigue or sleepiness

Before deciding to do a craniectomy, doctors will order an MRI or other imaging to get an idea of what is happening inside the skull. They will want to know where any injuries or blood clots are located so they can target the areas with the highest pressure when they operate.

You will be under general anesthesia during the surgery. Doctors need to carefully cut the skin to expose the bone of your skull. They’ll use a specialized drill to make holes in the skull so they can make boundaries around the section of bone they will remove. They’ll use a bone saw to cut from hole to hole, then lift the segment of the skull away.

Once the doctors can see the brain, they may remove blood clots or clear any excess fluid. They don’t replace the bone right away. Instead, they will give you a special helmet to protect your brain. The hole in the skull will stay open until the swelling and pressure have gone down. This procedure is different from another surgery called a craniotomy. For a craniotomy, doctors open the skull the same way. However, they replace the bone when they have finished operating.

After a craniectomy surgery, you will need to stay in the hospital. Other injuries or prior illnesses will have an effect on recovery time. The length of time you will need to stay in the hospital will depend on your overall health.

Replacing the bone. Doctors will decide when to close the opening in the skull based on how quickly the swelling in the brain goes down. It can be several months before they’re ready for this step. Doctors preserve the bone that they removed in the initial operation, and they will try to use it to close the hole. If they can’t use the original bone, doctors will use artificial bone to close the skull.‌

Prognosis after surgery. There may already have been some brain damage before the craniectomy is performed. Many people will need rehabilitation services for months or years after their craniectomy. Physical, occupational, and speech therapy can be helpful for people recovering from brain injuries.

If you or someone you know needs a craniectomy, you can talk to the medical team about the next steps for treatment. Recovering from brain surgery can be complicated, so it’s important to follow your doctor’s instructions.