Ancient Peruvian skulls found riddled with holes reveal the expertise of Inca cranial surgeries
Long before anesthesia and the advent of precision medical tools, humans were already performing complex surgeries on one another in effort to beat all sorts of ailments.
Among the most gruesome may be the act of trepanation – in which parts of the skull were scraped, cut, or drilled away to treat everything from headaches or injuries to suspected demonic possession.
Hundreds of prehistoric skulls bearing the tell-tale holes of trepanation have been found in Peru alone, dating as far back as the year 400 B.C.
Despite their prehistoric methods, researchers say the ancient neurosurgeons were experts at the task; during the Inca Empire, the survival rate for the procedure was roughly double what was achieved centuries later during the American Civil War.
According to a new study published to the journal World Neurosurgery, more than 800 skulls found in the Andean highlands of Peru show signs of trepanation, having one or more holes surgically cut into them
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,’ said David S. Kushner, clinical professor of physical medicine and rehabilitation at the University of Miami.
‘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?’
According to a new study published to the journal World Neurosurgery, more than 800 skulls found in the Andean highlands of Peru show signs of trepanation, having one or more holes surgically cut into them.
While this practice is known to have occurred all over the world, the experts say no area comes even close to matching Peru’s history with trepanation.
The hundreds of skulls, mostly found in burial caves and during excavations in the late 1800s and early 1900s, account for more trepanned skulls than all found in the rest of the world combined.
According to the researchers, hygiene likely played a key role in the success of Peru’s prehistoric cranial surgeries.
And, over nearly 2,000 years, these ancient surgeons refined their techniques to cause as little damage as possible.
The same could not be said for the Civil War surgeons, who often relied on unsterilized tools and probed open head wounds with their bare fingers.
The researchers were able to gauge survival of the patients based on evidence of healing activity; in situations where no signs of healing were present, they assumed the patient died during or soon after the surgery.
‘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,’ Kushner said, of the Civil War era surgeries.
‘We do not know how the ancient Peruvians prevented infection, but it seems that they did a good job of it.
‘Neither do we know what they used as anaesthesia, but since there were so many they must have used something – possibly coca leaves.
‘Maybe there was something else, maybe a fermented beverage. There are no written records, so we just don’t know.’
According to the researchers, the ancient Peruvians learned not to cut into the protective membrane around the brain.
In the earliest years, the survival rate was not great – from about 400 to 200 BC, it was even worse than those in the Civil War.
Evidence of trepanation can be found all over the world, dating back thousands of years. In the procedure, parts of the skull were scraped, cut, or drilled away to treat everything from headaches or injuries to suspected demonic possession
But, things changed dramatically over the next few centuries.
From the year 1000 to 1400 AD, survival rates jumped to as high as 91 percent in some samples.
During the Inca period, survival was at an average of 75 to 83 percent.
‘Over time, from the earliest to the latest, they learned which techniques were better, and less likely to perforate the dura,’ Kushner says.
‘They seemed to understand head anatomy and purposefully avoided the areas where there would be more bleeding.
‘They also realized that larger-sized trepanations were less likely to be as successful as smaller ones.
‘Physical evidence definitely shows that these ancient surgeons refined the procedure over time. Their success is truly remarkable.’
In the last century alone, neurosurgery has drastically evolved as our understanding of brain anatomy, physiology, and pathology improves.
Now, even the more invasive of these surgeries are often a success.
‘Today, neurosurgical mortality rates are very, very low; there is always a risk but the likelihood of a good outcome is very high,’ said Kushner.
‘And just like in ancient Peru, we continue to advance our neurosurgical techniques, our skills, and our knowledge.’