Trepanning

Trepanning, or trepanation, is a surgical intervention in which a hole is drilled or scraped into the human skull, perhaps the oldest surgical procedure with archaeological evidence; at a burial site in France dated to 6500 BCE, 40 of 120 skulls had trepanation holes. More than 1,500 trephined skulls of the Neolithic period have been found in Europe, Siberia, China and the Americas, and many show that the patient survived. Performed with tools of stone, obsidian, bronze or bone, it was described by Hippocrates and Galen and survives in modern craniotomy.