72 THE SCIENTIST | the-scientist.com
FOUNDATIONSDANIELLE KURINBY SUKANYA CHARUCHANDRACranial Craters, 1000-1250
I
n the long history of trepanation—removing a piece of the human
skull—residents of the Andes were relative latecomers, likely
beginning the practice around 400 BCE, based on archaeological
data. But ancient Peru stands out for the variety of techniques used
and the scale at which trepanation took place. More than 800 pre-
Columbian trepanned skulls have been discovered in that country,
more than in any other place in the world.
Many of those were unearthed by a team led by Danielle
Kurin, a bioarchaeologist at the University of California, Santa
Barbara. Beginning in 2010, she and her colleagues excavated sev-
eral burial caves containing the skeletal remains of 284 Chankas, a
people known to have been mortal enemies of the Incas. Of those,
32 had holes in their skulls—sometimes more than one. The holes
“were clearly man-made,” says Kurin. “They had some kinds of
cut marks.” Based on marks on the skulls, and on archaeological
and anthropological evidence from millennia of Andean culture,
she thinks the Chankas used trepanation to treat inflammation of
the brain, head injuries, and as a portal to welcome a frightened
soul back into its body.
The Chankas made the holes by scraping away at the skull
bone, boring or drilling holes into it, or by cutting in circles
or lines. Their tools included obsidian knives and other sharp
stones. Among the archaeological remains, which dated back
to circa 1000-1250 CE, Kurin also found drill bits that matched
the sizes of the trepanned holes. This suggests, she says, that the
Chankas had a “standardized toolkit.”
Many patients survived the procedure: Kurin found bony
extensions around the edges of their skull holes, evidence of
healing. Other mummified skulls with closely shaved hair
around the holes show signs that people had applied a poultice
to the wound site. “What we think we’re seeing over time is them
kind of experimenting with different surgical techniques,” says
Kurin. Patients whose holes were formed from scraping were the
most likely to survive, followed by those whose skulls had been
cut into; subjects whose skulls were drilled into were the least
likely to recover. Kurin also found that practitioners had tre-
panned dried, long-dead skulls in various ways, perhaps indicat-
ing that they were refining the techniques for use on the living.
Trepanation in Peru ended with the Spanish conquest.
Archaeologist and newspaper editor Ephraim George Squier,
sent to the country by Abraham Lincoln in 1863, acquired the
first-known trepanned skull from a cemetery near Cuzco, Peru.
The members of the New York Academy of Medicine examined
the cuts around the rectangular hole in the skull and determined
that it was made by human hands.
From about 1000-1400 CE, residents of what’s now Peru had
a success rate almost twice as high as that of Civil War battlefield
doctors of Lincoln’s time who performed trepanations to treathead wounds. Though the ancient Andeans lacked knowledge of
microbes or anesthesia, they weren’t operating in germ-ridden
hospitals, and they used newly made instruments for each patient,
notes Kurin.
She points out that the time period of the skulls she found
was one of cultural turmoil for the Chankas, following the col-
lapse of the Wari Empire, the political system that had ruled
them for about 500 years. “Along with this deprivation and vio-
lence, we see innovation and resilience,” she says. “We’re seeing
people who are not giving up... they’re innovating, and devel-
oping over time a pretty intense and invasive therapeutic means
of saving lives. And in many cases, they’re successful and [the
patients are] being cared for by the community.”HOLES IN THE HEAD:The skull of a young Chanka man who lived between 1170-
1270 shows evidence of two trepanations performed years apart. Kurin notes that
the hole near the top of the head was made fi rst, likely with a hand drill, while the
hole above the eye was made through repeated scraping with a sharp stone.