Trephining << trih FYN ihng >> is a surgical operation that involves cutting out a small, button-shaped piece of the skull. The operation is done with an instrument called a trephine. Trephining is used in the treatment of certain head injuries. It relieves pressure on the brain caused by bleeding between the skull and the brain. Trephining is also used to remove blood clots and to gain entry to the brain for certain surgical procedures.
Trephining is the earliest-known surgical treatment. Evidence of trephining has been found in human skulls that date to prehistoric times. Anthropologists have found trephined skulls throughout much of the world. Ancient peoples probably used trephining to release spirits that were believed responsible for headaches, mental disorders, and epilepsy. Some ancient warriors trephined the skulls of people they killed in battle. The warriors wore the piece of bone as a trophy or to ward off evil spirits. The Inca and other Indians of South America practiced trephining.
