What is craniectomy?

A craniectomy is a type of surgery to remove a portion of your skull. This helps relieve extra pressure on your brain.

Your brain sits inside the strong bones of your skull. These bones help protect your brain. During a head injury, blood vessels in the brain may break open and spill blood into the brain tissue. Swelling and inflammation from the injury may also increase fluid inside the brain. Because the skull fits around the brain tightly, there isn't a lot of extra space for extra fluid or inflammation. Both of these can lead to increased pressure inside the skull (increased intracranial pressure).

The extra pressure can damage the brain tissue. If the pressure increases too much, it may lead to permanent brain damage, coma, and death. A craniectomy is done to reduce this extra pressure on the brain and help prevent problems.

During a craniectomy, your care team puts you to sleep under general anesthesia. A neurosurgeon makes a cut on your scalp. The surgeon makes holes in your skull using a special drill. Using a power saw, the surgeon joins the holes and cuts out a piece of the skull. The surgeon may also make a cut in the membranes (meninges) that surround the brain. When the swelling has gone down and bleeding is under control, the surgeon may cover the area with a mesh material. Then the scalp is closed with sutures or staples.

After the surgery, you will need to wear a special helmet. This is to prevent damage to the area of your head that no longer has skull bone protecting it. After a few months, you may have a follow-up surgery called a cranioplasty. During a cranioplasty, your missing piece of skull will be replaced with your original bone or a synthetic material.

Why might I need a craniectomy?

You might need a craniectomy if you have increased pressure inside your skull. Your healthcare provider may first try to reduce this pressure in other ways. This might include using medicines to decrease swelling or draining cerebrospinal fluid(CSF). If this doesn’t work, you may need a craniectomy.

You may also need a craniectomy if you have severe neurological symptoms due to this increased pressure. Symptoms can include reduced consciousness. In this case, you may only have a short time before permanent brain damage and death if the pressure is not lowered. In these cases, craniectomy can be life saving.

Medical conditions that may lead to this increased pressure include:

  • Severe head injury that causes swelling or bleeding in or around the brain
  • Stroke (hemorrhagic or ischemic)
  • Subarachnoid hemorrhage
  • Brain infection
  • Blood clot in the brain’s venous sinus (large veins around the brain)
  • Swelling from a brain tumor

Not everyone with these conditions will need a craniectomy. Your healthcare providers will carefully watch your symptoms and the pressure inside your skull. If the pressure isn’t too high, the risks of the procedure may outweigh the benefits.

What are the risks of a craniectomy?

All surgery has risks. The risks of craniectomy include:

  • Infection
  • Seizures
  • Further brain injury
  • Brain bleed around the brain membranes (meninges)
  • Abnormal buildup of cerebrospinal fluid (hydrocephalus)
  • Blood clot or heart attack
  • Complications from anesthesia

Some of these can result in coma and death. There is also a risk that the craniectomy will not be successful at preventing brain damage from the original injury.

The healthcare provider will only advise a craniectomy if the benefits outweigh the risks. Your own risks may differ depending on the reason for your craniectomy, your age, and your overall health. Talk with your healthcare provider to find out what risks may apply to you.

The follow-up surgery to replace the missing skull may carry its own risks.

How do I get ready for a craniectomy?

Craniectomy is usually done as an emergency surgery. Because of this, you may not be able to prepare ahead of time. Your healthcare provider can let you or your family members know what other preparations are necessary.

Before the surgery, the medical team will ask about your medical history and give you a physical exam. Your team will be carefully watching you and working to reduce the pressure inside your skull. During this time, sedation and ventilator support may be needed.

You won’t be able to eat or drink anything before surgery. You may need imaging tests. These may include a computed tomography (CT) scan of your head. This is an imaging test that uses a series of X-rays and a computer to create images of the inside of the body. A CT scan helps your healthcare providers get more information about your condition.

What happens during a craniectomy?

The surgery is done by a neurosurgeon. This is a healthcare provider who has special training to perform brain or spinal cord surgery. Your medical team will include a team of specialized nurses. The team will let you know what will happen during the surgery. In general, you can expect the following:

  • You will receive general anesthesia through an IV line. This will let you sleep painlessly during the surgery and not remember it afterwards.
  • You may receive antibiotics through an intravenous line to help prevent infection.
  • Your team may put a breathing tube down your throat during the surgery to control your breathing.
  • Your healthcare team will carefully watch your vital signs, such as heart rate and blood pressure.
  • Your healthcare team will remove the hair from an area of your scalp.
  • After cleaning the area, the neurosurgeon will make an incision in your scalp. This is often done on the side of the skull with the most pressure.
  • After moving away the surrounding tissue, the neurosurgeon will use a drill and saw to remove a piece of your skull. The team will then carefully store the piece of skull in a freezer or in your abdomen. In some hospitals, this can't be done and the piece of skull is discarded.
  • The neurosurgeon will make a cut in the membranes that surround your brain.
  • The team will perform repairs as needed.
  • When the swelling has gone down, a mesh piece may be placed over the area.
  • The healthcare team will surgically close the scalp.

What happens after a craniectomy?

After the surgery, you’ll be closely watched in an intensive care unit. After the surgery, you might not wake up right away. It may take some time for the brain to recover from swelling and injury, so the outcome of the surgery might not be obvious for a while. You may need days or weeks in the hospital to recover. The outcome of the surgery will partly depend on whether the pressure caused any brain damage.

When you regain consciousness, you’ll be able to slowly become more active. Your medical team will give you instructions about your diet and your activity level. You shouldn’t have a lot of pain, but the scalp incision may hurt a little. You can have pain medicines if you need them.

After the surgery, you’ll need to wear a special helmet to protect the area that your skull is no longer covering. It is important to wear this exactly as your healthcare provider prescribes to help prevent injury to the area. During this time, it’s important not to do any activities that might lead to head injury. Your healthcare provider may give you more instructions about your recovery.

Let your healthcare provider know right away about any problems after your surgery, such as:

  • A scalp wound that is draining liquid or pus with hot or red skin
  • A scalp wound that is not healing well
  • Seizures
  • Vomiting
  • Fever
  • Shortness of breath

Depending on the nature of your injury, you may still have some symptoms after your surgery, such as muscle weakness. Your medical team can help form a treatment plan that makes sense for you. For example, physical and occupational therapy may help you regain some of your lost strength.

Your healthcare provider will tell you if and when you will need a cranioplasty, which involves putting back your original piece of skull bone or a new synthetic one

Next steps

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