Trephination (known also as trepanning, trepanation, trephining, or making a burr hole), is a surgical procedure, which involves the drilling of a hol
Trephination (known also as trepanning, trepanation, trephining, or making a burr hole), is a surgical procedure, which involves the drilling of a hole in the skull of a living person. Trephination is considered to be one of the oldest surgical procedures in the world, and evidence for this practice is found as early as the Neolithic period.
Trephination was carried out in many different societies over a long period of time, and even today, a form of trephination, known as craniotomy, is sometimes performed by surgeons. Considering that trephination was practiced by diverse societies throughout history, it is unsurprising that there were various reasons for this operation to be done.
The Neolithic Surgical Procedure
The word ‘trephination’ traces its origin all the way back to the Greek trypanon, which is “a borer, an auger, a carpenter’s tool; a surgeon’s trepan.” From Greek, this word became trepanum, “a saw for cutting out small pieces of bone from the skull” in medieval Latin. The word entered the English language through the Old French words trépaner and trepan, which is the act of drilling a hole in the skull, and the tool that was used for the process, respectively.
The perimeter of the trephination hole in this Neolithic skull is rounded off by ingrowth of new bony tissue, indicating that the patient survived the operation. This skull was discovered in Corseaux, Switzerland. (Rama / CC BY-SA 3.0 FR )
Although the name for this surgical procedure comes from the Greek language, trephination was performed long before the emergence of Greek civilization. The earliest evidence for trephination comes from the Neolithic period. According to a 2015 article by Miguel A. Faria in Surgical Neurology International , more than 1500 trephined skulls have been found at Neolithic sites around the world, including Europe, the Americas, Russia, and China. In addition, the report notes that “most reported series show that from 5-10% of all skulls found from the Neolithic period have been trephined with single or multiple skull openings of various sizes.”
The article also reports that the majority of trephined skulls belonged to adult males, though the procedure was performed on women and children as well. Furthermore, some of the skull openings showed signs of healing, which means that the patients survived the trephination. Others, however, did not, though it is impossible to tell if the surgery was performed on live individuals (who died during or after the surgery) or on deceased ones. It was also found that various techniques were used for the trephination. Apart from drilling, other methods of performing the surgery include scrapping and cutting the skull.
Bronze Age skulls with evidence of trephination found at Comps-sur-Artuby, France, in 1983. On show at the Archaeological Museum of Saint-Raphaël, France. (Wisi eu / CC BY-SA 4.0 )
Surviving the Test of Time: Ancient Middle East and the Classical World
Although trephination began in pre-history, it did not disappear as human society progressed. Clay tablets from ancient Mesopotamia, for instance, mention a type of surgery in which a knife is used to scrape the skull of a patient. After the procedure, plants were used to stop the bleeding. It has been pointed out that “since neither bone nor brain possess pain receptors, trephination should not have been particularly traumatic or painful after the scalp and soft tissue had been pierced.”
Two heads with trephining instruments in position. (Wellcome Images / CC BY 4.0 )
Nevertheless, hemorrhages from the exposure of spongy bone was a problem that had to be overcome by the surgeons. Whilst the Mesopotamians stopped the bleeding with plants, ancient Egyptian papyri from 3000 BC prescribed the application of fresh meat on wounds. As fresh meat contains hemostatic properties, it is able to decrease bleeding.
Trephination was also performed in the classical world. A number of trephined skulls from the Graeco-Roman period, for instance, have been found in the area of modern-day Israel. At the site of Acco, for instance, a trephined skull from the Hellenistic-Roman period was unearthed, whilst another four were discovered in a Roman cemetery in the Jordan Valley near Jericho. Apart from trephined skulls, evidence of trephination in the classical world can be found in the writings of the two most important physicians of the period, Hippocrates and Galen.
Although this skull shows four separate holes made by the ancient surgical process of trephination, they had clearly begun to heal. This suggests that although highly dangerous, the procedure was by no means fatal. This skull was excavated at a site near Jericho in 1958. (Wellcome Images / CC BY 4.0 )
Galen, for instance, provides a detailed discussion about the techniques and equipment involved, and recommends that physicians practice the operation on animals, in particular, the Barbary macaque ( Macaca sylvanus ). Incidentally, the physicians of Galen’s time were not the only ones who practiced trephination on animals. For instance, a trephined cow skull from Champ-Durant, France, has been dated to the Neolithic period.
It is unclear, however, whether the surgery was performed on the animal to save it, or for experimental purposes. Trephination continued in Europe during the Middle Ages, thanks to the immense influence of Hippocrates and Galen on the practice of medicine in the West.
A 3D digital image of the cow skull and its enigmatic hole, which was likely evidence of Neolithic trephination. The bar on the left represents 4 inches (10 centimeters). (Fernando Ramirez Rozzi / Nature)
From West to East, Trephination in Ancient China
One of Galen’s contemporaries was Hua Tuo, one of the most renowned physicians of ancient China. Hua Tuo lived during the Three Kingdoms period, a well-known era thanks to the Romance of the Three Kingdoms . This is a novel written during the Ming Dynasty, and is a highly romanticized account of the Three Kingdoms period, its events, and its people.
One of the stories in the novel suggests that trephination may have been practiced in ancient China as well. In this tale, Hua Tuo is in the service of Cao Cao, the ruler of Wei (one of the three kingdoms), and a major antagonist of the novel. Cao Cao was suffering from a severe headache, and summoned Hua Tuo to treat him. Incidentally, Cao Cao is said to have gotten the headache from a hallucinatory dream that he had after attacking a sacred tree with his sword.
Portrait of the physician Hua Tuo from a Qing Dynasty edition of The Romance of the Three Kingdoms. ( Public domain )
According to the Hua Tuo’s diagnosis, however, the root of Cao Cao’s headache lied in his skull, and may have been caused by a tumor in the brain. Therefore, he sought permission from the warlord to drill a hole in his head so that he could remove the tumor. In the novel, Cao Cao is painted as a paranoid character, and this episode is an example of his distrust of others. The warlord suspected that Hua Tuo wanted to kill him. Therefore, instead of allowing Hua Tuo to operate on him, Cao Cao had the physician executed.
It may be mentioned that the story of Hua Tuo and Cao Cao is not the only Chinese account suggesting trephination. Another source, known as the Esoteric Scripture of the Yellow Emperor , dates to the around the 2 nd century BC, and is a medical text. In this work, there is an account of a metal worker performing trephination on a leper to remove a cupful of worms or parasites.
The surgical procedure seems to be supported by archaeological evidence as well. In 2005, the mummy of a woman was unearthed from the Xiaohe Cemetery, in Xinjiang, an autonomous region in western China. The mummy, which has been dated to around 1600 BC, has a hole in her skull, which the researchers interpret as evidence of trephination. The researchers also observed that there was tissue healing around the site where the trephination was done, and the extent of the healing suggests that the woman lived for at least a month after the surgical procedure.
Inca Skull Dispels Racial Superiority Myth
Trephination was practiced in the New World as well, most commonly in the civilizations of the Andes, the best-known of which being the Inca Empire . The outside world seems to have been unaware of trephination in this region until the 19 th century.
In 1865, Ephraim George Squier, an American diplomat in Peru, was shown a skull at the ancient Inca city of Cuzco by Señora Zentino, reputed to be the “finest collector of arts and antiquities in Peru.” The skull, which came from a nearby Inca cemetery, had a large, rectangle-shape near its top front.
In addition to being a diplomat, Squier was also an archaeologist and ethnologist, and was intrigued by the artifact. He was of the opinion that the hole was not caused by an injury, but trephination, and that the individual survived the operation.
The original skull that Ephraim George Squier was shown with evidence of trephination. (Internet Archive Book Images / Public domain )
Squier managed to bring the skull back to the United States, where he presented it to members of the New York Academy of Medicine. The audience, however, was skeptical, believing that it was impossible for Peruvian Indians to successfully carry out such a dangerous surgical procedure. In addition to the notions of racial superiority held by the audience, their doubts were also fueled by the fact that patients of trephination at the time in the United States had a low rate of survival.
The year in which Squier presented the trephined skull was also the year the American Civil War ended. During that conflict, trephination seems to have become quite popular, as it was recommended by doctors for the cleaning and treating head wounds. Surviving the trephination, however, was a completely different matter. According to a recent study, between 46% and 56% of patients who had a trephination during the American Civil War did not survive. By contrast, Inca surgeons had a success rate of between 75% and 83%.
Another Peruvian skull found with evidence of the trephination surgery from 2000 years ago presumably to relieve a front cavity inflammation. (tsaiproject / CC BY 2.0 )
Not content with the reception of the medical community in New York, Squier brought the skull to Paris, where it was examined by Paul Broca, Europe’s leading expert on the human skull, in 1867. Having examined the skull, and consulted some of his colleagues, Broca came to the conclusion that the skull was trephined, and that the individual survived for a while after the surgery.
He presented his findings to the Anthropological Society in Paris in the same year, which generated a considerable amount of excitement in the country. Amongst other things, French anthropologists were motivated to look for even older trephined skulls in their own country. This led to the discovery of hundreds of trephined skulls dating to the Neolithic period. This discovery served to demolish the hitherto held idea that trephination was first performed by the Greeks during the time of Hippocrates.
Skull with evidence of trephination from the cave of Nogent-les-vierges, France, Neolithic period. (Wellcome Images / CC BY 4.0 )
Why Was Trephination Performed?
It is clear that trephination was primarily performed for medical purposes. This is visible, for instance, in ancient Greece. The Greek physician Hippocrates deals extensively with head injuries in his On Wounds in the Head . In this work, five types of head wounds are described, and trephination is recommended for all but one of them. The objective of trephination was to allow blood to drain from the skull.
According to Hippocrates, stagnant blood was bad, as it could decay and turn into pus. Therefore, trephination was a means to allow the blood from the injured part of the head to flow out before it turned bad. Later on, during the time of Galen, trephination was a standard procedure not only for draining blood, but also for relieving pressure, and to remove skull fragments after a traumatic accident. Trephination was also used in Europe as a treatment for epilepsy and mental illnesses. This tradition began with another ancient Greek physician, Aretaeus of Cappadocia, and lasted until the 18 th century.
Trephination was not performed solely for medical reasons. It has been suggested that this operation was sometimes done for ritual purposes. For instance, some skulls with large openings were found in the dolmens of Lozère, in southern France. In addition, several rounded, polished, and beveled pieces of cranial bones were found nearby. The man who made the discovery was P. Barthélémy Prunières, a friend and associate of Broca.
Human skull illustrating different methods of trephination. ( (Wellcome Images / CC BY 4.0 )
Both Prunières and Broca agreed that the bone fragments (which Prunières called rondelles) were probably carried or worn as amulets. The two men, however, disagreed about one of these skulls, which had “three elliptical cut-out areas along the parietal wall, the central of which seemed to have been smoothed or polished.” Whilst Prunières believed that the smooth area was caused by the use of the skull as a celebratory goblet, Broca argued that the opening had been made by scraping the skull with a sharp stone. This was probably performed early in the individual’s life, as the smoothing reflected an extended period of healing.
Trephination is no longer commonly practiced in today’s society. As a result of the progress made in medical knowledge, some of the views held by ancient physicians were found to be false. As a consequence, certain cures, including trephination, became obsolete. Nevertheless, a form of this surgical procedure, known as craniotomy, is sometimes performed.
Like the Chinese physician Hua Tuo, modern surgeons would only perform this operation in order to carry out surgery on the brain, for instance, to remove a brain tumor, or to treat an aneurysm. In addition, unlike trephination, which results in a permanent hole in the skull, the modern process requires the replacement of the removed bone fragment after the brain surgery is completed.
Top image: Ancient skulls bearing evidence of trephination – a telltale hole surgically cut into the cranium – found in Peru. Source: University of Miami
By: Wu Mingren
Bradford, A., 2018. What Is Trepanation?. [Online]
Available at: https://www.livescience.com/62591-trepanation-explained.html
Clower, W. T. & Finger, S., 2001. Discovering Trepanation: The Contribution of Paul Broca. Neurosurgery, 49(6), pp. 1417-1425.
Cohut, M., 2019. Curiosities of medical history: Trepanation. [Online]
Available at: https://www.medicalnewstoday.com/articles/326281
Daley, J., 2018. Inca Skull Surgeons Had Better Success Rates Than American Civil War Doctors. [Online]
Available at: https://www.smithsonianmag.com/smart-news/inca-head-crackers-had-better-success-rates-civil-war-surgeons-180969324/
Faria, M. A., 2015. Neolithic trepanation decoded- A unifying hypothesis: Has the mystery as to why primitive surgeons performed cranial surgery been solved?. Surgical Neurology International, 6(72).
Fawcett, K., 2016. Trepanation: The History of One of the World’s Oldest Surgeries. [Online]
Available at: https://www.mentalfloss.com/article/70309/trepanation-history-one-worlds-oldest-surgeries
Gross, C. G., 2019. A Hole in the Head: A History of Trepanation. [Online]
Available at: https://thereader.mitpress.mit.edu/hole-in-the-head-trepanation/
Harper, D., 2020. trepan (v.). [Online]
Available at: https://www.etymonline.com/word/trepan
Hershkovitz, I., 1987. Trephination: The Earliest Case in the Middle East. Mitekufat Haeven: Journal of the Israel Prehistoric Society, pp. 128-135.
Learn, J. R., 2016. Drilling Deep: How Ancient Chinese Surgeons Opened Skulls and Minds. [Online]
Available at: https://www.smithsonianmag.com/science-nature/how-ancient-chinese-surgeons-opened-skulls-and-minds-180961286/
Petrone, P. et al., 2015. Early Medical Skull Surgery for Treatment of Post-Traumatic Osteomyelitis 5,000 Years Ago. PLoS One, 10(5).
sciencemuseum.org.uk, 2020. Trephination. [Online]
Available at: http://broughttolife.sciencemuseum.org.uk/broughttolife/techniques/trephination
www.historyextra.com, 2019. Waht is trepanning?. [Online]
Available at: https://www.historyextra.com/period/prehistoric/what-trepanning-ancient-surgical-procedure-skulls-when-first/
Wylie, R., 2016. Why our ancestors drilled holes in each other’s skulls. [Online]
Available at: http://www.bbc.com/earth/story/20160826-why-our-ancestors-drilled-holes-in-each-others-skulls