Photos used in this article are courtesy of the San Diego Museum of Man and their publication entitled "Trephined Skulls" published in 1980.
Lower middle: 14.5 x 9.9 cm. thin coper tumi from cemetery near Ancón, central coast of Peru.
Upper middle: 14.1 x 10.6. Bronze tumi with effigy handle and worn blade. Probably from the Chimu culture, Moche Valley, north coast of Peru. A.D. 1000 to 1470.
Right: 13.0 x 9.1 cm. Thin copper tumi from cemetery near Ancón, central coast of Peru.
Sickness is as old as humankind and methods of attempting to cure it are as old as human culture. Supernatural and natural healing methods have been used by all peoples, ancient and recent, but surgery in general is a product of Western culture. An exception to this is the operation called trephination, the oldest known surgery. Trephined human skull fossils date as far back as 10,000 years to the people of the European Neolithic era and in a limited way in the Canary Islands, North Africa, Russia, and in the New World before the discovery of the Americas. The most extensive and expert practice of the operation by American Indians was in Peru and Bolivia, where numerous trephined skulls have been found in ancient burial sites. Some show no signs of healing, indicating the death of the patient during or shortly after the operation, but many show extensive healing of the bone.
The reason for performing this difficult surgical procedure has been the subject of varied speculation. In Peruvian practice there is considerable evidence that many of the operations were performed for the naturalistic purpose of removing a bone fragment that had been driven below the surface of the skull vault as the result of an injury, many presumably occurred during hand to hand fighting with stone headed war clubs. A considerable number of trephined skulls showing effects of battle are those of females and adolescents. These depressed fractures could have created intracranial pressure that resulted in illness and behavioral disturbance. Other fractures, not necessarily depressed, may have brought about blood clots and pressure on the brain - thus causing headaches and possibly aberrant behavior.
Another reason for trephination may have been an attempt at healing through supernatural means. It is possible that some of the South American operations were based on the theory that a malicious spirit had taken possession of the patient and was causing his sickness; therefore, opening the skull would allow the demon to escape. Or, since the agent causing the sickness was something thought to reside in the blood, the release of blood from the body was often a curative procedure, and the trephining operation invariably involved a considerable flow of blood.
There is some basis for believing that there were two concurrent reasons for trephining in Peru, perhaps by different types of practitioners. It is possible that there were two kinds of surgery: operations carried out by trained surgeons (the hampi-camayoc) with considerable knowledge and skill; and trephination undertaken as a supernatural curative procedure by shamans (sancoyoc) with little technical ability as surgeons. Many of the operations were carefully performed, suggesting that the surgery was done for the relief of some body disturbance other than that associated with injury, perhaps an organic or mental condition.
There were several methods used by the South American Indians for opening the skull. The most frequent was cutting the skull with four grooves releasing a quadrilateral section of bone which was elevated and removed. Sometimes the grooves were curvilinear rather than in straight lines. At times, considerable bone was removed by scraping before the cuts were made. Combinations of cutting and abrading or scraping were frequent. Another method was accomplished by drilling a number of small holes through the bone in a circular pattern and breaking through the walls separating the holes. It has been suggested that coca, which has local anesthetic properties and which is native to the Andes, could have been used to allay the pain of cutting through the scalp where the sensitive nerves in the head would be severed.
The South American surgeon of pre-Columbian times apparently used instruments of both stone and metal. Sharp flakes of obsidian (volcanic glass) were quite efficient cutting and scraping implements. Scalpels of copper or bronze, champi, were also made and apparently used in trephining. A classic type, the tumi, was in the shape of a half circular blade with a handle which was either flat or sculptured with an animal or human effigy.
That the native surgeon enjoyed a considerable degree of success in his trephining operations is proved by the fact that many of the skulls show some degree of healing in the trephined wound and as many as half of the specimens found show signs of advanced healing. A specimen was found that had been trephined five times with only the last scar showing signs of infection. This exceptional success rate for aboriginal American trephining may be typical, since the region in Peru where most specimens are found is one where the procedure was especially well developed.
Froeschner, EH: Two examples of ancient skull surgery. J Neurosurgery 76:550-552, 1992.
Stone, JL and Miles, ML: Skull trepanation among the early Indians of Canada and the United States. Neurosurgery 26:1015-1020, 1990.