Trepanning, also known as trepanation, trephination, trephining or making a burr hole (the verb trepan derives from Old French from Medieval Latin from Greek , literally "borer, auger"), is a surgical intervention in which a hole is drilled or scraped into the human skull. This procedure is one of the oldest surgical procedures to occur. Priests were the ones mainly performing trepanation. Those who were involved in trephining were sometimes called "medicine men". This group used materials such as stone, obsidian, bronze, or bone shaped into hand-held tools. The intentional perforation of the cranium exposes the dura mater to treat health problems related to intracranial diseases or release pressured blood buildup from an injury. It may also refer to any "burr" hole created through other body surfaces, including nail beds. The process to identify trepanation is through identification of a hole in the skull. The shape of the hole, cutting edges, and the healing process that is from the procedure also helps archeologists identify a trephined skull. A trephine is an instrument used for cutting out a round piece of skull bone to relieve pressure beneath a surface.
Trepanning was sometimes performed on people who were behaving in a manner that was considered abnormal. In some ancient societies it was believed this released the evil spirits that were to blame. Evidence of trepanation has been found in prehistoric human remains from Neolithic times onward. During that time, trephined skulls were commonly found in central Europe. After the Neolithic era, trephination skulls became less common due to the increased use of cremation. The bone that was trepanned was kept by the prehistoric people and may have been worn as a charm to keep evil spirits away. Evidence also suggests that trepanation was primitive emergency surgery after head wounds The primary theories for the practice of trepanation in ancient times include spiritual purposes and treatment for epilepsy, head wounds, mental disorders, and headaches, although the latter may be just an unfounded myth. Studies show that trepanation was used on individuals that were diagnosed with epilepsy, scurvy, frontal sinustis, intracranial disorders, diseases, hydrocephaly, and osteitis.
In modern eye surgery, a trephine instrument is used in corneal transplant surgery. The procedure of drilling a hole through a fingernail or toenail is also known as trephination. It is performed by a physician or surgeon to relieve the pain associated with a subungual hematoma (blood under the nail); a small amount of blood is expressed through the hole and the pain associated with the pressure is partially alleviated. Similarly, in abdominal surgery, a trephine incision is when a small disc of abdominal skin is excised to accommodate a stoma. Although the abdominal wall does not contain bone, the use of the word trephine in this context may relate to the round excised area of skin being similar in shape to a burr hole.
History
thumb|The perimeter of the hole in this trepanated [[Neolithic skull is rounded off by ingrowth of new bony tissue, indicating that the patient survived the operation.|218x218px]]
thumb|Skulls from the [[Bronze Age exhibited at the Musée archéologique de Saint-Raphaël (Archeological Museum of Saint-Raphaël), found in Comps-sur-Artuby (France). The subjects survived operations.]]
thumb|right|[[Dr. John Clarke trepanning a skull, , in one of the earliest American portraits. Clarke is alleged to have been the first physician to have performed the operation in the New England Colonies.]]
thumb|Trepanation instruments, 18th century; Germanic National Museum in Nuremberg
Prehistoric evidence
Trepanation dates back to 7,000–10,000 years ago, and in some areas may have been quite widespread. Trepanation is a worldwide practice that was extremely common during the Neolithic era. The main pieces of archaeological evidence are in the forms of human remains. At one burial site in France dated to 6500 BCE, 40 out of 120 prehistoric skulls found had trepanation holes. At the time only around 40% of people survived the procedure.
More than 1,500 trephined skulls from the Neolithic period (representing 5–10% of all cranial remains from that era) have been uncovered throughout the worldfrom Europe, Siberia, China and the Americas. Most of the trephined crania belong to adult males, but women and children are also represented.
There also exists evidence of trepanation being performed on a cow in France around 3400–3000 BCE. If performed while alive, the cow did not survive the procedure. It is unclear if this was performed as a veterinary procedure, medical experimentation or for other unknown reasons. However, it could be the earliest archaeological example of veterinary surgery or animal medical experimentation.
Pre-Columbian Mesoamerica
In the more recent times of postclassical pre-Columbian Mesoamerica, evidence for the practice of trepanation and an assortment of other cranial deformation techniques comes from a variety of sources, including physical cranial remains of burials, allusions in iconographic artworks and reports from the post-colonial period.
Among New World societies, trepanning is most commonly found in the Andean civilizations, such as pre-Incan cultures. For example, the Paracas culture Ica, situated in what is now known as Ica, located south of Lima. The oldest skull can be found in Paracas culture (700BC - AD300). Roman cultures left behind evidence of the practice by leaving lectures and writings written by scholars. (in modern-day Colombia) and the Inca Empire. The Inca Empire used trepanation as a treatment for epilepsy and medicine. The rate of skulls being found in Perú were significantly high. Between 11 and 40% of skulls were found throughout different parts of the area. Instruments and techniques used in Perú seemed advanced due to the number of trephined skulls that missed the midline of the skull. This suggests that these cultures tried to decrease the risks and damages of this procedure. Avoiding the midline of the skull reduced damage to the cerebral sagittal sinus. This reflects the improvement survival rate increasing over time which was 80%. The prevalence of trepanation among Mesoamerican civilizations is much lower, at least judging from the comparatively few trepanned crania that have been uncovered.
The archaeological record in Mesoamerica is further complicated by the practice of skull mutilation and modification carried out after the death of the subject, to fashion "trophy skulls" and the like of captives and enemies. This was a widespread tradition, illustrated in pre-Columbian art that occasionally depicts rulers adorned with or carrying the modified skulls of their defeated enemies, or of the ritualistic display of sacrificial victims. Several Mesoamerican cultures used a skull-rack (known by its Nahuatl term, tzompantli), on which skulls were impaled in rows or columns of wooden stakes. Even so, some evidence of genuine trepanation in Mesoamerica (i.e., where the subject was living) has survived.
The earliest archaeological survey published of trepanned crania was a late 19th-century study of several specimens recovered from the Tarahumara mountains by the Norwegian ethnographer Carl Lumholtz. Later studies documented cases identified from a range of sites in Oaxaca and central Mexico, such as Tilantongo, Oaxaca and the major Zapotec site of Monte Albán. Two specimens from the Tlatilco civilization's homelands (which flourished around 1400 BCE) indicate the practice has a lengthy tradition.
Specimens identified from the Maya civilization region of southern Mexico, Guatemala and the Yucatán Peninsula show no evidence of the drilling or cutting techniques found in central and highland Mexico. Instead, the pre-Columbian Maya apparently used an abrasive technique that ground away at the back of the skull, thinning the bone and sometimes perforating it, similar to the examples from Cholula. Many skulls from the Maya region date from the Postclassic period (), and include specimens found at Palenque in Chiapas, and recovered from the Sacred Cenote at the prominent Postclassic site of Chichen Itza in northern Yucatán.
Ancient China
Before 2007, archaeological evidence of trepanation in ancient China was nonexistent. Since Chinese culture mainly focuses only on traditional Chinese medicine that usually entails non-surgical treatments such as acupuncture, balancing Qigong, cupping, herbal remedies, etc. The resulting misconception was that trepanation was not practiced in ancient China. Trepanned skulls have been found since the 1940s throughout China. Some of these skulls have dated back to the 3rd and 1st century BCE. However, in 2007, Han and Chen from the Institute of Archeology, Chinese Academy of Social Sciences looked at six trepanned skulls spanning between the Neolithic period through the Bronze and Iron Ages ( years ago) found in five different locations. Along with the discovery of these trepanned skulls, another collection of 13 trepanned skulls was discovered and dated to 3,000 years ago. The hair may or may not have been shaved depending upon the site of the operation.
Trepanning at the Kisii people in Kenya was filmed in 1958.
Pre-modern Europe
Trepanation was known to prehistoric Europeans, with some populations having impressive success rates of 78% in the Iron Age. Central Europe during the Neolithic era had an important understanding of the risks of trepanation. They used aids like rudimental anesthetic, antiseptic, and technological aids.
In the graveyards of pre-Christian (Pagan) Magyars, archeologists found a surprisingly high frequency (12.5%) of skulls with trepanation, although more than 90% only partial (these served probably ritual purposes). The trepanation was performed on adults only, with similar frequencies for males and females, but increasing frequency with age and wealth. Additional research has suggested that the male to female proportion of these individuals was 2:1. Children accounted for only 7% of trephined skulls.
During the 16th and 17th centuries, around 80% of people survived the procedure of trepanation. This was later made unnecessary by the development of the orbital transit lobotomy where a spike was inserted through the eye-sockets.
Trepanation is a treatment used for epidural and subdural hematomas, and surgical access for certain other neurosurgical procedures, such as intracranial pressure monitoring. Modern surgeons generally use the term craniotomy for this procedure. Unlike in folk practices, a craniotomy must be performed only after diagnostic imaging (like computed tomography and magnetic resonance imaging) has pinpointed the issue within the skull; preoperative imaging allows for accurate examination and evaluation. Unlike in trepanation, the removed piece of skull (called a bone flap) is typically replaced as soon as possible, where it can heal. Trepanation instruments, nowadays being replaced with cranial drills, are now available with diamond-coated rims, which are less traumatic than the classical trephines with sharp teeth. They are smooth to soft tissues and cut only bone. Additionally, the specially designed drills come with a safety feature that prevents the drill from penetrating into the brain tissue (through the dura mater). Along with antisepsis and prophylaxis of infection, modern neurosurgery is a common procedure for many reasons other than head trauma.
In documented cases of trepanning done in Africa and Oceania during the 20th century, patient survival rate was seen to be approximately 90%. In China, twelve shaman corpses in a tomb were found with trephined bodies because they also had duties of doctors. They understand trepanation as a way to balance the body and energy, spiritual and physical health. On the other hand, it was thought that cerebral disorder arise from the loss of spiritual image in ancient Peru, illness developed after being separated from body. Trepanation would have been done in order to allow the spirit to reenter the body. In these cases, the patient may have suffered from paralysis, cerebral palsy, severe depression, or intellectual disability. During the beginning and middle of the Neolithic period, flint was common used as a tool but as time went on, stones became more refined in shape and were eventually made from bronze. Such instruments includes the terebra serrata, made to perforate the cranium by positioning the instrument's pointed end against the cranium and manually rolling the instrument's shaft back and forth between the surgeon's two hands.<!-- this citation applies to all 5 items -->
The scraping method was found to be the most common in prehistoric times.The differences in method vary in the amount and depth of bone being removed. The trepanation surgical procedure includes exposure of the dura mater without damaging the underlying blood vessels, meninges, and brain. Over time, the skin will reform over the puncture site, but the hole in the skull will remain.
The location of the trepanation on the skull varies by geographical region and period, common locations are the frontal and the occipital bones. In most cases, trepanation was a one-off operation, with only a small percentage of the trepanned skulls having undergone more than one surgery. In those with multiple openings, the extent of bone remodelling helps identify whether the opening was done at around the same time or at different times during the individual's life. The operation leaves very minimal space for error and a high incidence of mortality if the dura mater is penetrated. Additionally, there is a high risk of infection if the operation is conducted with contaminated tools or improper sanitary wound care. If the infection is not caught and treated immediately, it can be fatal or lead to significant and permanent brain damage. Tools like fresh flint is considered a sterile surgical instrument that could reduce infection.
Voluntary trepanation
Since the early 1960s, voluntary trepanation has been performed by people interested in "enhancing mental power and well-being". The practice of trepanning also continues today due to belief in various pseudoscientific medical benefits. For example, some have tried trepanation as a means of emulating the "third eye", in order to achieve clairvoyance or as a means of maintaining a "permanent state of euphoria". Other proponents claim that trepanning results in increased blood flow. Individuals have practiced non-emergency trepanning for psychological purposes. A prominent proponent of the modern view is Peter Halvorson, who drilled a hole in the front of his own skull to increase "brain blood volume".
In a chapter of his book Eccentric Lives & Peculiar Notions, esotericist John Michell cites Huges as pioneering the idea of trepanning in his 1962 monograph, Homo Sapiens Correctus, which is often cited by advocates of self-trepanation. Among other arguments, Huges contends that children have a higher state of consciousness and since children's skulls are not fully closed, one can return to an earlier, childlike state of consciousness by self-trepanation. Further, by allowing the brain to freely pulsate Huges argues that a number of benefits will accrue.
Michell quotes Joey Mellen's book, Bore Hole. At the time the passage below was written, Joey and his partner, Amanda Feilding, had made two previous attempts at trepanning Mellen. The second attempt ended up placing Mellen in the hospital, where he was reprimanded severely and sent for psychiatric evaluation. After he returned home, Mellen decided to try again. He describes his third attempt at self-trepanation:
<blockquote>After some time there was an ominous sounding schlurp and the sound of bubbling. I drew the trepan out and the gurgling continued. It sounded like air bubbles running under the skull as they were pressed out. I looked at the trepan and there was a bit of bone in it. At last!</blockquote>
Feilding also performed a self-trepanation with a drill, while Mellen shot the operation for the short film Heartbeat in the Brain, which was long thought to have been lost. Portions of the film can be seen in the documentary A Hole in the Head.
Michell also describes a British group that advocates self-trepanation to allow the brain access to more space and oxygen. Other modern practitioners of trepanation claim that it holds other medical benefits, such as relief from depression and from other psychological ailments. In 2000, two men from Cedar City, Utah, were prosecuted for practicing medicine without a license after they performed a trepanation on an English woman to treat her chronic fatigue syndrome and depression.
In 2023, Michael Raduga, a Russian lucid dreaming researcher, performed self-neurosurgery that included trepanation, electrode implantation, and electrical stimulation of the motor cortex. The goal was to stimulate the brain during REM sleep, sleep paralysis, and lucid dreams.
There are very few cases of self-trepanation. Only five cases in a five-year span have been reported as self-trephination. In English literature, only seven cases known to have a patient with schizophrenia perform self-trephination. A female patient, 56 years old was diagnosed with schizophrenia. This mental disorder is associated with neurocognitive impairment. She had delusions of having foreign body objects that resultedin her picking at the skull until dura matter was the exposed. The wound measured 4 x 3x 4 cm on the top of the skull. After being hospitalized she lost mobility, balance, and the ability to perform daily activities.
Another patient, 65 years old, used a power drill to drill a hole through his scalp and skull. The laceration was identified behind the hairline in the left frontal area. The hole was 1 cm in diameter and missed the midline. A television program that implied that trephination would lead to self-fulfillment prompted him to perform trepanation on himself. It took him 30 minutes to get through the skull which followed by hospitalization. The patient reported that he felt no improvement of his well-being. He was never diagnosed with psychotic or suicidal thoughts before this incident, but after being hospitalized he was diagnosed with dissocial personality disorder
By the 20th century, the ancient practice of trepanning evolved into procedure of bone marrow biopsy, which became vital for identifying illnesses including anemia, leukomia, lymphoma, and tuberculosis. This change happened as doctors realized the need of accessing the inside of bones for diagnostic purposes, especially in the treatment of blood-related ailments. The initial tools of trepanning as crown trephine transitioned into the biopsy needles in modern medicine, such as the Vim-Silverman needle and the Jamshidi needle.