Japan’s trepanning history is full of holes

by Rob Gilhooly

In his 1967 study, “Prehistoric and Early History of Trepanation,” Professor F.P. Lisowski of the University of Tasmania, Australia, cites the work of two anthropologists who suggested that trepanation might have been practiced in Japan.

One of them, Michael Rykel, reported in 1962 on five skulls unearthed in Hokkaido that may indicate trepanation was long ago practiced by the Ainu.

However, Japanese experts are hesitant to agree. There is no evidence it was practiced in prehistoric times, they say, and the evidence that it may have been used medically as far back as the Kamakura Period (1185-1333) is “problematic.”

Furthermore, domestic wars in Japan’s past complicate research, as it is difficult to determine whether a pierced skull may be evidence of trepanation — or simply the remains of someone dealt a blow by a pike, sword or other piercing weapon.

Takao Suzuki of the Tokyo Institute of Gerontology, who studied aspects of trepanation at the Smithsonian Institution, says that in regions of the world where the practice is thought to have been customary in prehistoric times, it is generally associated with tribal ritual or surgical operation.

“Where it was a custom . . . or surgical operation, you invariably find a certain percentage of the unearthed skulls show signs of having been trepanned,” he says. “But in Japan there are insufficient cases to assume such a custom existed.”

Where trepanned skulls have been unearthed in other regions of the world, such as South America and Europe, evidence of cutting, scraping or sawing of the cranium is often accompanied by signs of new bone growth around the opening, Suzuki says. This indicates that the person recovered from the operation.

Trepanation is known to have been used surgically to treat internal bleeding resulting from a head injury. When the skull is depressed by a heavy blow to the head, the membranes covering the brain can hemorrhage. Drilling a hole in the skull releases the accumulated blood. Keiji Kawamoto of Osaka’s Kansai Medical University says there are some curious examples of skulls from recent times with holes resembling trepanation burrs. He believes this process may well have been employed during the Edo Period (1603-1867). Indeed, there is mention of trepanning procedures in Japanese medical texts from the early 1700s that were used to train physicians, according to a paper titled “Wagakuni ni Okeru Noshinkei Geka (Neurosurgery in Japan).”

These texts were based on translations from Dutch medical tomes and were penned by some of Japan’s earliest and most acclaimed doctors. Though evidence is scarce, it is likely the procedures were put into practice.

Archaeological data, however, doesn’t corroborate the supposition. Suzuki insists that most pierced skulls that have been found are likely to be the result of war or other injuries. This conclusion is reached “due to the lack of new bone growth around the hole, which means the subject must have died immediately after,” he says.

As a few skulls show signs of new bone growth, though, “It is impossible to tell if these were due to a successful surgical procedure, or a combat injury which the subject survived,” he adds.

Another reason both Suzuki and Kawamoto are not convinced trepanation was practiced back then is the lack of documentation. Trepanation in those days would require extreme technical skill, they explained, making it almost certain the procedure would have been documented.

“By the Edo Period, medicine was very advanced, and we know from documents that surgeons had developed an operation for tumors,” Suzuki says. “If trepanation had also been practiced, it seems unimaginable that no documents remain.”