Trepanning


Trepanning, also known as trepanation, trephination, trephining or making a burr hole, is a surgical intervention in which a hole is drilled or scraped into the human skull. 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. 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. 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 to remove shattered bits of bone from a fractured skull and clean out the blood that often pools under the skull after a blow to the head. Hunting accidents, falls, wild animals, and weapons such as clubs or spears could have caused such injuries. Trepanations appear to have been most common in areas where weapons that could produce skull fractures were used. The primary theories for the practice of trepanation in ancient times include spiritual purposes and treatment for epilepsy, head wound, mental disorders, and headache, although the latter may be just an unfounded myth.
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 ; 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

Prehistoric evidence

Trepanation dates back to 7,000–10,000 years ago, is perhaps the oldest surgical procedure for which there is archaeological evidence, and in some areas may have been quite widespread. 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 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. Trepanation has also been found in the Muisca Confederation and the Inca Empire. In both, even cranioplasty existed. 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, on which skulls were impaled in rows or columns of wooden stakes. Even so, some evidence of genuine trepanation in Mesoamerica 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 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. 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 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. In 2015, an intact 3,600-year-old mummy with a trepanned skull was discovered. Meanwhile, the oldest trepanned skull analysed by Han and Chen was radiocarbon dated to around 5,000 years ago and discovered at the Fuija site in Guangrao, Shandong. The skull, which belonged to an adult male, exhibited a right parietal calvarial defect with evidence of scraping by a trephine-like tool. Additionally, bone regeneration and smooth edges suggest that the subject recovered from the surgery and lived a relatively long time afterward.
The 3,600-year-old perforated skull of a mummified female dating to 1615 BCE was found in the Xiaohe tomb in China's Xinjiang Uygur Autonomous Region. The only known female with a trepanned skull, it showed signs of bone spurs growth and retraction of the edges, suggesting that she also survived the surgery. Found in a massive burial site, this mummy was one of the hundreds found in the "Little River" Tomb complex.
The Bronze Age was found to be the period with the largest number of trepanned skulls in ancient China.

Medieval East Africa

Trephining has a long history in East Africa. Bones of depressed fractures were elevated by surgeons of Bunyoro-Kitara. 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.
Trepanation was also practised in the classical and Renaissance periods. Hippocrates gave specific directions on the procedure from its evolution through the Greek age, and Galen also elaborates on the procedure. During the Middle Ages and the Renaissance, trepanation was practiced as a cure for various ailments, including seizures and skull fractures. Out of eight skulls with trepanations from the 6th to 8th centuries found in southwestern Germany, seven skulls show clear evidence of healing and survival after trepanation, suggesting that the survival rate of the operations was high and the infection rate was low.
In the graveyards of pre-Christian Magyars, archeologists found a surprisingly high frequency of skulls with trepanation, although more than 90% only partial. The trepanation was performed on adults only, with similar frequencies for males and females, but increasing frequency with age and wealth. This custom suddenly disappeared with the Magyars' conversion to Christianity.
A small area near Rostov-on-Don, in southern Russia, may have been a centre for ritual trepanning, around 6000 years ago, according to archeologists who discovered remains of eight recipients of the practice, within a small area, all with the incision in the unusual obelion position, high on the back of the head.
During the 16th and 17th centuries, around 80% of people survived the procedure of trepanation.

Modern medical practices

The prefrontal leucotomy, a precursor to lobotomy, was performed by cutting a trephine hole into the skull, inserting an instrument, and destroying parts of the brain. 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 has pinpointed the issue within the skull; preoperative imaging allows for accurate examination and evaluation. Unlike in trepanation, the removed piece of skull 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. 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%.