Overview
A craniectomy is an operation in which a surgeon removes part of the skull and does not replace it right away. The term "craniectomy" explains how the surgery is performed. It does not refer to one disease or diagnosis.
A craniectomy may be done when swelling or pressure inside the skull becomes dangerous. This can happen with conditions such as a brain tumor, also called a neoplasm. It also may be done to make room for monitoring equipment, such as electrodes that record brain activity. The surgery may be done as an emergency or planned procedure, depending on the condition being treated.
If the swelling improves and your health is stable enough, the opening in your skull may be repaired later with a procedure called cranioplasty.
You may hear several similar terms while receiving care. Craniectomy, craniotomy and cranioplasty sound similar, but they describe different procedures.
In a craniotomy, the surgeon removes a piece of skull to reach the brain and usually replaces it before the operation ends.
Cranioplasty is a later surgery to repair the opening in the skull after a craniectomy.
Types
There are several types of craniectomy. The name usually shows the reason for surgery or the part of the skull involved.
Decompressive craniectomy
A decompressive craniectomy is done to relieve dangerous pressure on the brain caused by swelling. The surgeon removes part of the skull to give the swollen brain more room. This may help lower pressure inside the skull.
Suboccipital craniectomy
A suboccipital craniectomy removes bone from the lower back part of the skull, near the cerebellum and brainstem. The term "suboccipital" describes where in the skull the surgery is done.
This type of craniectomy may be used to treat swelling or other conditions that affect the back part of the brain.
Strip craniectomy and craniosynostosis
A strip craniectomy may be used to treat babies with craniosynostosis. In this condition, one or more bones in the skull grow together too early. The procedure removes a narrow strip of bone to allow the skull to grow more typically.
Unlike other types of craniectomy, this procedure is not used to treat brain swelling or pressure. It is done to improve skull growth in infants.
Why it's done
A craniectomy is done when the brain needs more room. It also may be done when part of the skull must be removed so the surgical team can treat a serious brain condition, such as a brain tumor.
The skull is made of bone and cannot stretch or make more room for the brain. When the brain swells, pressure inside the skull can increase. This pressure can reduce blood flow to the brain or push brain tissue out of position. Removing part of the skull creates space for the swollen brain and may help lower the pressure.
In many cases, the goal is to lower dangerous pressure inside the skull, called intracranial pressure. Lowering the pressure may help reduce the risk of further brain injury.
Craniectomy may be used for some people with:
The healthcare team considers many factors before recommending a craniectomy, including:
- Brain-imaging findings.
- The location and amount of swelling.
- Signs that swelling is shifting brain tissue.
- Changes in brain function.
- How the condition is changing.
- Whether another treatment may be enough.
Whether a craniectomy is recommended depends on your condition and its cause. Some people need surgery right away. In other cases, your healthcare team has time to review brain scans, symptoms and other test results before recommending treatment.
Risks
Like any major brain surgery, a craniectomy has risks. Your risks depend on your overall health, the reason for surgery, and whether the procedure is planned or done in an emergency.
Possible risks and complications include:
- Bleeding.
- Infection.
- Blood clots.
- Seizures.
- Fluid buildup around the brain, also called hydrocephalus.
- Continued brain swelling.
- New or worsening changes in brain function.
Sinking skin flap syndrome, also called syndrome of the trephined, is a possible but uncommon complication of craniectomy. After a craniectomy, skin covers the opening in the skull. In sinking flap syndrome, the skin over this area can sink. This may affect how the brain works. Symptoms may include headache, weakness, changes in thinking or other changes in brain function. Cranioplasty, which repairs the opening in the skull, is the main treatment for sinking skin flap syndrome.
Some complications following craniectomy happen because of the condition that made surgery necessary, not because of the surgery itself. For example, a severe brain injury or stroke can cause long-term problems with movement, speech or thinking.
How you prepare
Many craniectomies are done in an emergency, so there may be little or no time to prepare. In some cases, the surgery can be planned in advance.
Before a planned craniectomy, you may have imaging tests, such as a brain CT scan or brain MRI. You also may have a physical exam, blood tests or other tests to help your healthcare team plan the procedure.
Before surgery, tell your healthcare team about:
- All prescription medicines you take.
- Medicines you buy without a prescription.
- Vitamins.
- Herbal products.
- Other supplements.
- Any alcohol use.
- Any tobacco use.
- Any medicine allergies.
Your healthcare team tells you whether to stop or change any medicines before surgery. Some medicines, such as blood-thinning medicines, may need to be changed. Do not stop taking any medicine unless your healthcare team tells you to.
Follow your care team's instructions about eating and drinking before surgery. These instructions help make anesthesia as safe as possible.
What you can expect
Before the procedure
If your craniectomy is planned, you will change into a hospital gown when you arrive at the hospital. An intravenous (IV) line is placed in a vein to give you fluids and medicines, including anesthesia medicines, during the procedure.
A member of your healthcare team reviews your medical history, medicines and allergies. You may have blood tests, imaging tests or other exams when you arrive at the hospital to help plan the surgery.
You likely will meet with the anesthesia team before surgery. A craniectomy usually is done under general anesthesia, which means you are in a sleeplike state during the procedure.
The surgical team positions you so the surgeon can reach the area that needs treatment. Depending on where the surgery will be performed, part of your hair may be shaved.
During the procedure
The surgeon makes a cut, called an incision, in the scalp. Where the cut is made depends on the part of the skull that needs to be reached.
The surgeon removes part of the skull. This is done to create more room for the brain or to reach and treat the affected area. In some craniectomies, the surgeon opens the dura, the protective covering around the brain. The surgeon may enlarge this opening to give the brain more room.
The surgeon does not replace the removed piece of skull during the craniectomy.
The incision in the scalp is closed. You may be taken to an intensive care unit (ICU) or another area where you can be closely monitored while you recover.
After the procedure
After surgery, you are closely monitored while you recover. Your healthcare team checks for continued brain swelling, seizures, infection and changes in brain function. Recovery depends on the surgery and the condition that made it necessary.
Recovery and rehabilitation
Recovery is different for everyone. Some people improve over days to weeks. Others need months of recovery and rehabilitation. The timeline depends on the cause and severity of the brain condition, your overall health and whether you have any complications.
Rehabilitation may be part of recovery. Depending on your needs, your healthcare team may recommend physical, occupational or speech therapy to help improve movement, communication, thinking and daily activities.
You will have follow-up appointments so your healthcare team can monitor your recovery and discuss whether and when cranioplasty is recommended.
Protecting the skull after craniectomy
After a craniectomy, part of the skull is temporarily missing. Until the opening is repaired, that part of the brain has less protection and needs to be protected.
You need to take precautions to protect your head from injury during recovery. Depending on your condition, you may need to wear a protective helmet during some activities or rehabilitation.
The precautions you need and how long you need them depend on your condition, the size and location of the skull opening, and your stage of recovery.
Cranioplasty after craniectomy
The piece of skull removed during craniectomy generally does not grow back on its own. If the opening in the skull needs to be repaired, another surgery called cranioplasty may be done.
Cranioplasty is surgery to repair the opening in the skull after a craniectomy. The repair may use the original piece of skull or another material.
Cranioplasty is done after the brain has had time to heal. The timing depends on factors such as:
- How much the swelling has gone down.
- How well you are healing.
- Whether you developed an infection.
- Your overall health.
Results
Results of your craniectomy depend on why you had the procedure. If the surgery was done to reduce brain swelling, the goal is to protect the brain while swelling lessens. Your healthcare team monitors the swelling and your recovery with exams and imaging tests, such as CT scans or MRI scans. Recovery is different for everyone. Some people recover quickly, while others may need rehabilitation and ongoing follow-up care.
Rehabilitation can include physical, occupational or speech therapy. A cranioplasty to repair the opening in the skull may be recommended after the brain swelling has improved.
Sept. 03, 2026