Ancient Peruvian was buried with tools for cranial surgery

Ancient Peruvian was buried with tools for cranial surgery
Sican National Museum

Archaeologists recently unearthed an unusual tomb in a temple complex at the Huaca Las Ventanas archaeological site near Lambaeque, in northern Peru. The site belonged to the Sican culture, one of the several complex societies that flourished prior to the rise of the Inca Empire (around 1400 CE) in northern Peru. The tomb reveals that the Sican—like several other Indigenous cultures spanning the length of Peru and about 4,000 years of history—practiced a type of cranial surgery called trepanation.

The surgeon’s tomb

Trepanation is the delicate art of cutting or drilling a hole in a person’s skull. It sounds brutal, but it can help relieve pressure on the brain from inflammation or bleeding, such as might occur after a head injury. Modern surgeons sometimes use a similar procedure, called a craniotomy, to relieve pressure from bleeding under the membrane that surrounds the brain.

Of course, modern craniotomies are guided by CT scans and MRIs. Ancient surgeons just had to go by sight and feel, which makes their success rates pretty remarkable. Archaeologists in Peru have found the remains of about 800 trepanation patients from the last 4,000 years, and the majority of them show signs of bone healing around the edges of the hole—which means they survived serious head trauma and cranial surgery to treat it.

Assuming that the tools belonged to the tomb’s occupant, it tells us that the Sican surgeon buried at Huaca Las Ventanas wasn’t a butcher; he was, as Sican National Museum director Carlos Elera put it in a press statement, “a specialist in cranial trepanations, and his surgical instruments were oriented to everything that was human skull surgery.”

A whole suite of surgical tools wrapped in a bundle was lying alongside the long-dead surgeon; archaeologists found dozens of wooden-handled bronze awls, needles, and knives in various sizes. Most of the knives were single-edged blades, but one was clearly special. The semicircular blade, called a tumi, was a staple of both surgery and ritual sacrifice for the Sican, their predecessors the Moche, and later the Inca. Ritual tumis were large and elaborate, but ancient surgeons used a smaller, more utilitarian version for trepanation.

“We are comparing the instruments of a modern surgeon with these objects, to see what similarities they have,” said Elera. One difference is obvious: The bronze in most of the tools contains a fairly large amount of arsenic, which would probably raise some eyebrows in a modern surgical suite.

On the other hand, the Sican surgeon would probably have recognized the tools used by his colleagues several hundred years earlier and several hundred miles to the south, in the Paracas culture of what’s now southern Peru. Archaeologists have found very similar surgical tools—awls, knives, needles, and tumis—at Paracas sites. But while the Sican surgeon used bronze tools, Paracas surgeons favored razor-sharp obsidian blades. They share that preference with some modern surgeons, who use obsidian scalpels for their sharpness and precision.

Two examples of the surgeon’s work also joined him in his grave; archaeologists found two frontal bones (the bone that makes up the forehead). One belonged to an adult, one belonged to a child, and neither originally belonged to the surgeon (his was still attached to the rest of his skull). Both had been carefully cut using a classic trepanation technique.

The surgeon's toolkit included at least 50 knives, along with needles and awls in various sizes.
The surgeon’s toolkit included at least 50 knives, along with needles and awls in various sizes.
Sican National Museum

Impressive survival rates

Elera and his colleagues dated the surgeon’s tomb at Huaca Las Ventanas to sometime between 950 and 1000 CE—about 400 years before the rise of the Inca Empire. By the time the Sican surgeon first picked up a bronze tumi, surgeons from cultures all over what’s now Peru had already been performing trepanations for about 3,000 years. The oldest evidence of trepanation in Peru dates to around the same time ancient Greek physicians were first writing down guidelines for the procedure.

And, based on the archaeological record, they actually saved lives. Archaeologists in Peru have found the remains of at least 800 people, dating from 4,000 years ago up until the cusp of Spanish colonization, with neatly drilled or cut holes in their skulls. In a 2018 study, University of Miami School of Medicine professor David Kushner, along with a team of archaeologists, examined those skulls for evidence of surgical survival rates. They found that Inca cranial surgeons kept their patients alive about twice as often as American Civil War surgeons, who also practiced trepanation 800 years later.

From 1000 CE to about 1400 CE (which mostly includes the Sican surgeon’s lifetime), between 75 and 83 percent of cranial surgery patients lived long enough for the bone to start remodeling itself around the opening. Some surgeons were clearly better than others; Kushner and his colleagues found survival rates as high as 91 percent at some sites. Surgeons during the US Civil War, on the other hand, managed only a 44 to 54 percent survival rate.

The difference, Kushner and his colleagues speculated, was hygiene. Civil War hospitals, especially in the field, were notoriously dirty. Surgeons didn’t sterilize their tools or even wash their hands. Infection probably killed more soldiers on both sides than bullets alone could have done. Most of the ancient Peruvian surgeons probably weren’t working under battlefield conditions.

“We do not know how the ancient Peruvians prevented infection, but it seems they did a good job of it,” said Kushner back in 2018. “Neither do we know what they used as anesthesia, but since there were so many [surgeries], they must have used something. There are no written records, so we just don’t know.”

The recently unearthed surgeon’s tomb at Huaca Las Ventanas may shed some light on that. His kit included a piece of bark, which Elera and his colleagues speculate may have been medicinal. Some types of willow bark, for instance, have traditionally been used as painkillers and anti-inflammatories (that’s where the compound in aspirin comes from).

The good doctor

Although cranial surgery was a refined practice in Peru 1,000 years ago, ancient surgeons faced a bit of a learning curve. In Kushner and his colleagues’ 2018 study, people who had trepanations between 400 and 200 BCE had about even odds of surviving. But over time, Peru’s ancient surgeons clearly improved their knowledge of anatomy and surgical techniques.

The trick, according to Kushner, was to make smaller holes, avoid piercing the dura (the membrane that surrounds the brain), and avoid areas that are likely to bleed heavily.

And by 950-1000 CE, when the Sican surgeon at Huaca Las Ventanas practiced his trade, the profession was highly skilled and—based on the riches with which the surgeon was buried—well respected. His grave goods included not just surgical tools but a golden mask with feathers around the eyes, a large bronze breastplate, and a set of gilded copper bowls.

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