A craniotomy is an operation, or surgery, on the brain. A craniotomy involves making an opening in the skull so that surgery can be done on the brain.

A craniotomy may be necessary to treat several medical conditions including:

• Brain tumors

• Bleeding (hemorrhage) or blood clots (hematomas) from injuries (subdural hematoma or epidural hematomas)

• Weaknesses in blood vessels (cerebral aneurysms)

• Abnormal blood vessels (arteriovenous malformations or AVM)

• Damage to tissues (dura) covering the brain

• Pockets of infection in the brain (brain abscesses)

• Severe nerve or facial pain (such as trigeminal neuralgia or tic douloureux)

• Trauma to the skull and repair of skull fractures

• Some forms of seizure disorders (epilepsy)

Craniotomy is a complex procedure. Craniotomy for the treatment of certain brain conditions such as subarachnoid hemorrhage or cerebral aneurysm greatly increases the risk of death following surgery. Better processes of care in the hospital may reduce the risk of death (mortality) from craniotomy.