The body's natural healing response to injury is to swell. Swelling in the brain, however, can be dangerous because the skull restricts the swelling and pushes on the brain.
Removing a portion of the skull can reduce the risk of severe brain damage, and may even be life-saving.
- Injury can cause dangerous pressure in the brain that increases blood pressure, slows blood flow, and damages the brain.
- In some cases, brain swelling can cause fatal injuries.
- A decompressive craniectomy involves removing part of the skull to reduce pressure in the brain.
- A large number of people who undergo decompressive craniectomy still die from brain swelling, despite the surgery.
Decompressive craniectomy procedure
During a decompressive craniectomy procedure a part of the skull may be removed to reduce pressure on the brain.
During the operation, a surgeon removes the portion of the skull that is causing the pressure on the brain. This is usually the area of the skull that covers the injury.
The surgery is performed under general anesthesia, which means the person will be asleep, will not feel the procedure, and will have no memory of the operation.
A craniectomy begins with a cut in the scalp. The surgeon peels back the skin and tissue underneath it to reveal the skull.
Because the skull is a hard bone, the doctor will use a drill, and a bone saw to cut into it.
Once the surgeon has removed the bone, they will stop any bleeding before closing the wound with stitches.
After surgery, the bone taken from the skull is usually stored in a freezer. If the individual recovers, the bone may be replaced.
Why would you need one?
The most common reasons for a decompressive craniectomy are:
- Traumatic brain injury (TBI): This is an injury to the brain caused by physical force. It can occur after any experience that results in a sharp blow to the head. With a TBI, brain swelling is usually immediate.
- Stroke: Some strokes can cause brain swelling. The high blood pressure this swelling causes is a risk factor for more strokes.
Doctors may consider a decompressive craniectomy when the brain swells and other strategies to reduce pressure do not work.
Decompressive craniectomy is normally the last resort
Brain surgery can be dangerous, particularly for someone with a brain injury, so providers try nonsurgical measures first. Those treatments might include:
- medication to decrease the swelling
- oxygen therapy
- lowering body temperature
In some cases, a doctor may try a less invasive surgery called a ventriculostomy, which drains the cerebrospinal fluid to decrease the pressure.
Most people will spend some time in an ICU after a decompressive craniectomy procedure.
People who undergo a decompressive craniectomy are already in critical condition due to a brain injury or stroke. So to a large extent, the length of their recovery depends on the injuries that created the need for surgery in the first place.
Most people will spend time in the intensive care unit (ICU).
Some people will remain unconscious for days or weeks following surgery. Some may even be in a coma or vegetative state.
Following a craniectomy, it is essential to protect the brain from further injury. This usually requires the individual to wear a custom-fitted helmet for several weeks to several months.
Less frequently, a person might wear a temporary brain implant to stabilize the brain and skull. A surgeon will remove this implant at a later date.
How long do people stay in the hospital?
Most people will stay in the hospital for several weeks following surgery. It can take months, and possibly years, to recover from the surgery and injury. A person who has had a decompressive craniectomy will require continual monitoring for additional signs of brain swelling, and any signs of infection will need prompt antibiotic treatment.
Extensive rehabilitation can help people regain as much brain function as possible. This might include speech therapy, physical therapy, and exercise therapy.
Once a person has sufficiently recovered from the surgery and original injury, a surgeon will replace the missing portion of the skull. This procedure, called a cranioplasty, offers further protection to the brain once the swelling has gone down.
If the original bone is in good condition and has not grown dangerous bacteria, the surgeon may use that bone. Otherwise, they might replace the bone with titanium or synthetic bone.
Likelihood of death is high. This is because the injuries that warrant this operation are almost always life-threatening. Many people do not survive despite the surgery. For most people, however, the craniectomy improves their chances of living longer and having fewer impairments.
A 2016 study compared people who underwent decompressive craniectomy with those who had other medical treatments for brain swelling.
The study reported that 6 months following surgery, 26.9 percent of those who underwent surgery had died, compared to 48.9 percent who did not undergo surgery. In 42.8 percent of the surgical group, doctors described outcomes as "favorable," compared to 34.6 percent in the non-surgical group.
People from both groups had significant rates of disability, but decompressive craniectomy lowered the rate of all forms of disability. For instance, 8.5 percent of people who did not receive surgery were in a vegetative state at 6 months, compared to 2.1 percent of those who had surgery.
Risks and complications
As with all major surgery, there may be substantial risks with a decompressive craniectomy.
Decompressive craniectomy is lifesaving, but it carries substantial risks. Those include:
- extensive brain bleeding
- damage to the brain's blood vessels
- brain damage due to oxygen deprivation
- brain infection
- leakage of the cerebrospinal fluid
Additionally, some people may experience complications due to anesthesia.
People who have a brain injury may experience complications such as blood pressure and breathing difficulties. Rarely, someone may experience a life-threatening allergic reaction to anesthesia.
The most serious complications of surgery occur in the weeks immediately following surgery. Some people, however, develop new symptoms much further in the recovery journey.
Because the operation is risky, people should talk openly about the risks and benefits of surgery.
Facing a decompressive craniectomy can be scary. However, people should know that the high rate of complications following surgery is due primarily to the severe injuries that have caused the need for surgery. For people who have extensive swelling that does not respond to other treatments, a craniectomy may be the best and only treatment option.
With extensive rehabilitative care, medical monitoring, and prompt treatment of any complications, this procedure may enable some people to live normal lives.