For much of human history, the work of a surgeon has not been pretty.
Without modern luxuries like anaesthetics or even basic tools like clamps, surgery was a bloody, violent and largely unsuccessful affair.
But incremental developments over millennia, followed by the leaps and bounds of recent centuries, have turned the profession into a life-saving one which many of us will come into contact with.
Despite this, surgeon and author Dr Ira Rutkow believes there's a widespread lack of understanding about the job.
So in his new book, Empire of the Scalpel: The History of Surgery, Dr Rutkow unpacks this surprising story.
Stone Age neurosurgery
The use of surgery stretches back much further than many may realise – with evidence of neurosurgery in the Stone Age.
"There are many skulls from the Neolithic Era (around 10,000 — 4,500 BCE) that have been discovered, which have holes in the cranium," Dr Rutkow says.
"There would have been a shaman or a cave person who was cutting into the skull and removing a portion of the skull."
Dr Rutkow says we know that some patients survived "because the skull bone needs time to regrow and the person has to be alive for that bone to regrow."
He says there were two reasons for drilling skulls at this time, a practice known as "trepanning": It was either for releasing evil spirits (which was likely a mental illness) or reviving someone who was unconscious.
From the Neolithic Era onwards, trepanned skulls have been found in Europe, Africa, Asia and South America.
Ancient surgical texts
There is evidence that surgery was practised by several ancient civilisations.
A number of medical texts from ancient Egypt have survived, including the Edwin Smith Papyrus (named after American Egyptologist Edwin Smith who bought it in 1862). It dates back to around 1,600 BCE and is the oldest known surgical treatise on trauma.
The papyrus details 48 cases of wounds, injuries and fractures and, unlike other texts from the time, offered not just magical remedies, but surgical ones.
"The fascinating thing about the Smith Papyrus is that it does not have much of the mystical character of prior Egyptian writings," Dr Rutkow says.
"It was very matter of fact. It told surgeons or individuals who were operating at the time what to do, when to do it and how to do it. So it became a surgical dictionary."
There is also evidence of surgery being practised in ancient India.
An Indian medical text called the Sushruta Samhita from the 6th century BCE outlines surgical procedures from the era.
It details several methods of skin grafts — or transplanting a piece of skin from one part of a person's body to another.
Barber surgeons
A separation between medicine and surgery began to form in ancient Greece, according to Dr Rutkow.
"That began a long tradition in medicine, where those who worked with their hands were looked down upon by the physicians, who were supposedly better educated (and) more thoughtful."
"The physicians were the thinkers, the surgeons were the doers. Throughout history … the doers were not regarded as highly as the thinkers."
In the Middle Ages, a trend emerged in Europe that showed how societies valued the profession: The rise of the barber surgeon.
As barbers possessed a number of sharp tools, they were called on to perform surgery, ranging from bloodletting to amputating limbs.
It was a case of 'come for a haircut, stay for the dangerously rudimentary surgery' (and then perhaps die of an infection afterwards).
They even formed an association called the United Company of Barber Surgeons, a precursor of the Royal College of Surgeons of England.
The 16th century
There were two important developments in the 16th century that started to pave the way for surgery to become what we know today.
For much of history, in many societies, there were taboos about what could be done with dead bodies. Because of this, physicians and surgeons would dissect animals, learn about their anatomy and apply it to humans.
But Flemish man Andreas Vesalius was convinced there was much to learn from dissecting human corpses.
"(He thought) it was ridiculous that we (were) looking at apes and gorillas and pigs, and comparing their anatomy to human anatomy," Dr Rutkow says.
So Vesalius began to perform cadaver dissections, mapped their insides and, in doing so, became known as the founder of modern human anatomy.
One of the main queries for practitioners at the time was how to stop the (often very severe) bleeding during surgery.
"If you're going to do (an operation) and there's so much bleeding that you can't see the roadmap that anatomy has provided, you need to learn how to stop bleeding," Dr Rutkow says.
There were some options for an amputation, such as pouring boiling oil or using red hot irons after cutting a limb off. But this was, to put it mildly, painful.
So in the 16th century, Frenchman Ambroise Paré invented a pair of forceps that allowed arteries and veins to be grasped and tied off, so that bleeding could be stopped.
Pain was 'a blessing'
For thousands of years, the only way to somewhat subdue a patient for surgery was with liquor, opium or other drugs.
These offered little distraction from the pain so patients usually had to be restrained and spent the surgery screaming and thrashing.
When anaesthesia was invented in the 1840s, it was a watershed moment for surgery.
But, despite obvious benefits, anaesthesia was not widely welcomed immediately.
"(Some surgeons) felt that the writhing of the patient during an operation ... provided excess energy that they needed to get through the operation and allow them to recover. Of course, that was not true."
And some European religious leaders pushed back at the idea.
Dr Rutkow says religious leaders argued against anaesthesia on the basis that pain was "a blessing" and "a challenge for the faithful."
But he says these sentiments are not as surprising as we may think.
"That concept of not accepting (new ideas) and just sticking with conservative values that have been around for thousands of years ... That problem exists today. And it probably will still exist into the future."
The final piece of the surgery puzzle was stopping infection.
There was little regard for hygiene (as surgeons worked barehanded and surgical items were reused without proper cleaning), so patients frequently got infections and died.
French chemist and microbiologist Louis Pasteur discovered bacteria in the 19th century. Soon after, British surgeon Joseph Lister posited that bacteria was causing infections in wounds.
"Lister provided a way to start antisepsis … But his concept of antisepsis was only finally accepted at the turn of the 20th century," Dr Rutkow says.
What next?
Surgery has continued to develop and Dr Rutkow says the last 20-30 years have been another period of "revolution."
Changes in anaesthesia, along with the use of small incisions and minimally invasive operations, have meant that day surgery is far more common than in the past.
"(In many cases) we're no longer doing these large incisions where patients would have to stay in hospitals and rehabilitate for days, if not weeks," Dr Rutkow says.
"This is all leading to robotic surgery and the ability to do smaller operations, less dissection, less bleeding and getting patients home and back to the normality of life."
And he expects many more leaps and bounds to come in the years ahead.
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