Last year, archaeologists excavating burial caves in the south-central Andean province of Andahuaylas in Peru discovered the remains of 32 individuals dating back between 750 and 1000 years and, incredibly, they found evidence of 45 separate surgical procedures on the skulls of the individuals.

Cranial surgery, known as trephination, is one of the first ever surgical practices and is known to have begun in the Neolithic era. It involves drilling a hole in the skull of a living person to cure illness such as convulsions, headaches, infections or fractures. Although there is some merit to the technique and it is still practiced today for the relief of subdural haematoma, there is evidence to suggest that in ancient times people believed that illness was caused by a trapped spirit and that drilling a hole would allow the spirit to escape.

The skulls found in Peru show evidence that sections of the cranium were removed using a hand drill or a scraping tool, and this was conducted, of course, without the use of modern luxuries like anaesthesia. While some have suggested the skull traumas may have been the result of torture, Kurin explained that some of the remains showed evidence of their hair having been shaved and a herbal remedy placed over the wound, which all point to the fact that this was an attempt to heal sick or injured individuals.

"When you get a knock on the head that causes your brain to swell dangerously, or you have some kind of neurological, spiritual or psychosomatic illness, drilling a hole in the head becomes a reasonable thing to do," said Danielle Kurin, a specialist in forensic anthropology.

An example of a skull that has undergone trephination, Peru. Photo source .

According to Kurin, it appears that they were experimenting with different ways of cutting into the skull. "It looks like they were trying different techniques, the same way we might try new medical procedures today," she said. The idea was to go all the way through the bone but not touch the brain, so it took incredible skill and practice.

Amazingly, it appeared that many of the surgeries were successful as there was evidence of both the original wound and the surgical wound having been healed. When a patient didn't survive, it seems that the skull was used for education purposes. "As bioarchaeologists, we can tell that they're experimenting on recently dead bodies because we can measure the location and depths of the holes they're drilling," she said. "In one example, each hole is drilled a little deeper than the last. So you can imagine a guy in his prehistoric Peruvian medical school practicing with his hand drill to know how many times he needs to turn it to nimbly and accurately penetrate the thickness of a skull."

According to Kurin, while these ancient people can’t speak to us directly, they do provide information that allows us to reconstruct some aspect of both their lives and their deaths.

By April Holloway