The 'patient' died at the age of between 30 and 40, and archeologists are confident the markings on the ancient bone were from surgical intervention and not ritualistic practices. Picture: Sergey Slepchenko

A step by step academic investigation into how Bronze Age medics conducted trepanation operations in Siberia has been conducted based on a male skull found last year in the Nefteprovod II burial ground at Anzhevsky archaeological site, southeast of Kansk in Krasnoyarsk region.

The 'patient' died at the age of between 30 and 40, and archeologists are confident the markings on the ancient bone were from surgical intervention and not ritualistic practices.

They also believe that this man, whose remains were buried with a cranked or crooked knife, lived for a period of time after his surgery. His left parietal bone had an opening with evident signs of bone healing, as well as indications of an inflammatory reaction on the bone plates.

The suspicion is that his eventual death was caused by long term post operative inflammation. This man was not by any means the earliest known case of trepanation in Siberia: there are, for example, some dating to the Neolithic period.

Former surgeon Dr Sergey Slepchenko, now a researcher at the Institute of Archaeology and Ethnography, Novosibirsk, explained that 'the key to successful surgery was the patient's complete trust and confidence that the surgeon had the necessary skills and knowledge to carry out such an operation'.

A male skull was found last year in the Nefteprovod II burial ground at Anzhevsky archaeological site, southeast of Kansk in Krasnoyarsk region. Pictures: Anton Vibornov, The Siberian Times

A critical element was plainly enabling the patient - in this case a male from an unknown ancient culture similar to the Karasuk people, but not one of them - to enter an 'altered state of mind' in which the pain was minimised.

Plants supposed as being used as painkillers in other locations are absent from Siberia, and instead Slepchenko and his colleagues identified flora which were used by indigenous peoples here to used to bring a person to an altered state of mind.

There are an intriguing number of such potential painkillers: for example, some ethnic groups used juniper and thyme in Shamanic practices; the Nivkhi people burned wild rosemary sticks and leaves; northern indigenous peoples used fly agaric mushrooms (Amanita muscarica), a powerful hallucinogen.

The 'most obvious', however, was probably cannabis.

But the consumption of fungi, together with other Shamanic practices, such as ecstatic dancing or the use of a drum, is seen as a likely method of altering the conscious state of a patient and so reducing pain to the extent necessary to carry out surgery.

The left parietal bone had an opening with evident signs of bone healing, as well as indications of an inflammatory reaction on the bone plates. Pictures: Sergey Slepchenko

'For the preparatory phase of the operation, we can only use our best guess,' he said. 'However, based on the shape and type of inclination of the edges, we may infer that the patient lay in a supine position with the head turned to the right.

'The surgeon probably stood face-to-face to the patient on the left side. Or the surgeon may have fixed the head with his left arm or between his knees and operated with his right hand.'

Deductions by the team indicate that 'while the surgeon made an incision, an assistant helped by stretching the skin at the edges of the wound, as well as passing instruments and other materials'. The experts believe that it is 'likely' that 'a wide cut to the bone through the skin and underlying tissues was performed', said Dr Slepchenko.

'Such a dissection of the scalp was described in Hippocrates' work' - some 600 years after this Siberian trepanation. 'After the area was cut, the wound would have been opened to organize a 'surgical field'.

A traditional Karasuk-style knife that was found in the grave, but there was no suggestion this was an implement used for the surgery. Picture: Anton Vibornov

'The skin and aponeurosis were peeled off the underlying bone. The next phase was bone scraping. Changes in bone as a result of healing prevent us from guessing precisely what instrument was used for trepanning or how it was made.

'We cannot definitely state that this operation was carried out with a specialised instrument. Nevertheless, some sort of medical instruments existed in Siberia and were widely used for postmortem manipulations. These same instruments may have been applied for trepanation.'

Dr Slepchenko said: 'Judging by the shape of the hole, I would suggest it was some kind of scraper, rather than a knife. The scraping lasted until dura mater was exposed after which the trepanation area could be enlarged in width but never below.

'The high survival rates after trepanation in early times may be explained by the fact that operations were mostly extradural. Penetration of dura mater causes the development of intracranial hematomas because of bleeding between the meninges.

Shamanic practices, such as ecstatic dancing or the use of a drum, is seen as a likely method of altering the conscious state of a patient and so reducing pain. Picture: Vera Salnitskaya

'Subsequent complications, such as wound abscess, meningitis, and brain abscess, lead to death.

'The fact that individuals, including (this patient), lived for some period of time after the trepanation suggests that the dura mater remained intact long enough for strong signs of healing to appear.'

About the operation, he said: 'The opening was covered with skin after trepanation. Some blood filled the area between dura mater and inner surface of the aponeurosis since blood clots prevented further bleeding from the diploe' - the spongy bone separating the inner and outer layers of the compact bone of the cranium.

But the wound 'could not be too tight' to minimise the risk of infection. 'It is not clear if sutures and/or bandages were applied; nor is it clear how the wound was drained. Yet some ethnographic records give evidence that these simple devices were implemented during trepanation.

'One of the most probable and most dangerous complications of trepanation is bleeding which develops immediately after the skin incision. As a consequence of further scraping, bleeding from blood vessels is accompanied by bleeding from the diploe bone.

Examples of Tagar bronze knife stored in Minusinsky local history museum, which are believed to have been used in ancient surgeries. Picture: Tatyana Chikisheva

'It is important that the dura mater remains intact since its damage may cause injuries to the sagittal venous sinus located under its plates. To minimize bleeding and reduce pain, the operation had to be carried out as fast as possible by a presumably highly skilled surgeon.

'It is not clear how they stopped the bleeding.'

Obviously no written records are left but the experts surmise that 'herbs or red-hot objects' were used here.

The Karasuk culture refers to a group of Bronze Age societies from the Aral Sea to the upper Yenisei in the east and south to the Altai Mountains and the Tian Shan around the years 1500~800 BC. The Karasuk were farmers who practiced metallurgy on a large scale. They are considered to be the first people in Siberia who used horses for riding.

Yet the academics believe the brain surgery patient to have been from another grouping from an unknown culture with a similar lifestyle.

The grave in which the trepanned skull was found - had been robbed in ancient times. Little more than the skull remained but there were additionally fragments of tubular bones of the upper limbs and of ribs.

Modern skull after the 'surgery' conducted by Alexei Krivoshapkin (top) copying ancient techniques (bottom). Pictures: Alexei Krivoshapkin

A traditional Karasuk-style knife that was found in the grave, but there was no suggestion this was an implement used for the surgery. Two stone arrowheads were also located.

The study on this reconstruction of trepanation is published in the International Journal of Osteoarchaeology.

The archaeological excavations and the study of the finds was possible thanks to the quick and professional work of the Security and Rescue Archaeology Department in the Institute of Archaeology and Ethnography, Siberian Branch of Russian Academy of Sciences.

The archaeologists who took part were: Dr Anton Vibornov, Dr. Vyacheslav Slavinsky, Dr Alexander Tsybankov.

Dr Slepchenko is a researcher at the Security and Rescue Archaeology Department, at the Institute of Archaeology and Ethnography, part of the Siberian Branch of Russian Academy of Sciences.