Perhaps the oldest form of medical treatment is trephination. Trephined human skull fossils date as far back as 10,000 years to the people of the European Neolithic era. It has also been practiced 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 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 which means that the patient lived for many years after the surgery.

The word trephination is derived from Greek meaning auger or borer. And that's exactly how the procedure is performed. An opening is made in the skull by a circular saw, exposing the brain beneath. In a modern hospital, neurosurgery is a major event and the operation is performed under the strictest of sterile conditions, for fear that the brain will become infected. The fact that this operation was performed under less than sterile conditions by ancient peoples -- and they survived -- is remarkable to me!

The reasons for performing this risky surgical procedure have been the subject of varied speculation. In Peruvian practice there is considerable evidence that many of the operations were performed for the purpose of removing a bone fragment that had been driven beneath the surface of the skull vault as the result of an injury. Many such injuries are presumed to have occurred during hand to hand fighting with stone headed war clubs. Also, there are skulls with depressed skull fractures -- such an injury would have created increased intercranial pressure, which would have been lethal if left untreated.

Another reason for trephination may have been an attempt at healing through supernatural means. A modern neurosurgeon will tell you that symptoms of increased intercranial pressure -- resulting from swelling caused by a brain injury -- may manifest themselves as headaches, confusion, nausea, vomiting, belligerent behavior, and uncoordinated movements. Not too hard to see how such could have been interpreted as possession by some manner of malicious spirit by an ancient physician. Opening the skull was thought to allow the demon to escape. It also reduced the pressure on the brain, which provided relief of the symptoms.

If the agent causing the sickness was something thought to reside in the blood, the release of blood from the body was believed to be a curative procedure, and the trephining operation invariably involved a considerable flow of blood. A modern neurosurgeon treats a subdural hematoma (blood clot) by evacuating the clot through a window that has been made in the skull.

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 groves releasing a quadrilateral section of bone which was elevated and removed. Sometimes the groves 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 surgeon of pre-Columbian times 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 were also made and used in trephining. A classic type, called 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! Pretty amazing if you ask me. :)