Decompressive hemicraniectomy was first described in 1905 by Harvey Cushing. It is a surgical procedure that involves the removal of a portion of the skull in order to allow swelling brain tissue to expand outward through the artificial opening instead of compressing against the inside of the skull, thus preventing damage caused by brain compression.  This procedure can also refer to the removal of parts of contused hemorrhagic brain with the same intentions.  Hemicraniectomy prevents further brain injury by decreasing intracranial pressure (pressure inside the skull).

High intracranial pressure is dangerous because it causes the compression and subsequent death of brain tissue.  Increased pressure in the brain can also cause the brain to press down on the spinal cord, which can be fatal. Increased intracranial pressure can be caused by several conditions, including but not limited to stroke (bleeding inside the cranium), trauma (which causes brain swelling), and hemispheric encephalitis. For this procedure, which is performed under general anesthesia, the surgeon will remove a part of the skull and cut the dura mater, the tough outer layer of the meninges (protective tissues that cover the brain) to allow the brain to swell.

Katya Alimova and Justin F. Fraser, MD