You would have been safer undergoing skull surgery in ancient Peru than you would have during the American Civil War. This is the startling conclusion from a new study that has looked at how likely a person was to survive trepanation – in which a hole was cut into the skull – across various cultures in antiquity.
For thousands of years people around in the world, from cultures as diverse as the Mayans in the Americas to the Renaissance in Europe, practiced trepanation. The method of making the holes varied, with some societies opting for drilling into the cranium while others instead used an abrasive technique to scrape away at the bone, but the results were remarkable.
Despite this deeply invasive work – sometimes removing not inconsiderable chunks of skull – evidence shows that many people survived the surgery, living long after the operations took place. Astonishingly, the survival rates have been found to have been far better for people who’d undergone skull surgery in Incan Peru than during the American Civil War hundreds of years later.
“There are still many unknowns about the procedure and the individuals on whom trepanation was performed, but the outcomes during the Civil War were dismal compared to Incan times,” explained David S Kushner, co-author of the study published in World Neurosurgery. “In Incan times, the mortality rate was between 17 and 25 percent, and during the Civil War, it was between 46 and 56 percent. That's a big difference.”
“The question is how did the ancient Peruvian surgeons have outcomes that far surpassed those of surgeons during the American Civil War?”
Presumably, those practicing during the Civil War were better equipped, educated and trained but there are a number of likely reasons why the Inca's surgery was so successful.
One of these is simply hygiene. During the Civil War, little was done to minimize the risk of infection, with surgeons frequently using unsterilized tools and bare fingers to break up blood clots. “If there was an opening in the skull they would poke a finger into the wound and feel around, exploring for clots and bone fragments,” said Kushner.
How the ancient Peruvians managed to prevent infection is not known because there are no written records. But with the frequency with which they conducted trepanations, and the fact that some people had multiple holes in their heads, it is thought most likely that the Incas had developed some form of anesthesia, quite possibly derived from coca leaves.
Another factor might just have been practice. The Incan surgeons performed hundreds of trepanations to deal with headaches, seizures, and fractures, and over the centuries refined their techniques and dramatically improved their survival rates.
Luckily, "Today, neurosurgical mortality rates are very, very low; there is always a risk but the likelihood of a good outcome is very high," Kushner said. "And just like in ancient Peru, we continue to advance our neurosurgical techniques, our skills, our tools, and our knowledge."
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