When might someone need an emergency craniectomy?

An emergency craniectomy may be needed when swelling, bleeding or an injury causes dangerously high pressure inside the skull. A craniectomy is surgery to remove part of the skull. The skull can't expand to make room for a swollen brain. Rising pressure can reduce blood flow to the brain and cause brain damage. In severe cases, the pressure can push brain tissue out of its usual position. This is called brain herniation, and it can be life-threatening.

A few conditions may lead to the need for an emergency craniectomy. These conditions include a severe brain injury with pressure inside the skull that can't be controlled without surgery or a large stroke. Some types of bleeding in or around the brain also may require emergency craniectomy. For example, a subdural hematoma is bleeding between the brain and the tough outer covering of the brain. If surgery can remove the bleeding but the brain is too swollen to safely put the piece of skull back in place, the surgeon may leave it out.

Having one of these conditions doesn't always mean that you need a craniectomy. In some emergencies, surgery may be needed right away because the brain is severely swollen or there are signs of brain herniation. In other cases, the healthcare team may first use medicines or other treatments to lower pressure inside the skull. A craniectomy may be considered if the pressure stays too high despite these treatments. The decision also depends on what is causing the swelling or pressure.

The care team looks at several factors when deciding whether a craniectomy is needed. These factors can include information from brain scans, the amount of swelling or bleeding, pressure inside the skull, and changes in how the brain is working. For example, the team may look for a drop in the person's level of consciousness or changes in how the pupils react to light.