The thread through the fistula served first to keep the tunnel open, so that any pus that formed in it could drain out by running down the thread. That stopped an abscess developing or recurring. The thread was then tied more tightly so that, in the days and weeks that followed, it would gradually dig its way through the tissues of the anal sphincter. So slowly, that the damaged muscle fibres behind the thread would have time to heal again. It was a fistulotomy in slow motion, which spared the anal sphincter. The cutting effect of Hippocrates’s thread was mainly due to the coarse flax, but that could break prematurely. That was the reason for the horsehair: you could use it to pull a new flax thread through the fistula without having to use the tin probe again.
Today, a wide range of methods are tried out to treat high anal fistulas; for example, by filling them up with various substances or sealing them off with mucus membrane. But the most commonly used method remains Hippocrates’s classical seton stitch, a simple thread that slowly cuts through tissues. Synthetic materials and elastic are used rather than flax and horsehair, but the effect is the same and, in many cases, the results are satisfactory.
Félix de Tassy had thus obviously not learned his procedure from the books of Hippocrates, as he used a knife rather than a thread on the king’s fistula. He may have read about this method in the work of successful English fistula surgeon John Arderne of Newark-on-Trent. Arderne wrote a handbook on fistulas in 1376, with illustrations of his operational methods and the instruments he had made himself. Arderne treated all fistulas with a straightforward fistulotomy, nothing fancy. And yet he achieved much better results than his colleagues. His fame was probably due to the mildness of his post-operative care, which enabled the cut-open fistulas to heal much better than those operated on by his fellow surgeons. He stemmed the flow of blood from the wound with a piece of cloth rather than with a branding iron and had the wound cleaned with water rather than with corrosive salves and administering enemas. Louis XIV, too, benefited from this milder approach.
Arderne had been a military surgeon in the Hundred Years’ War, where he had seen a large number of knights suffering from fistulas. In their heavy armour, they bumped up and down in the saddles of their horses, while the sweat from their exertions, fear and heat ran down their backs and into the crack between their buttocks. The continual irritation led to an abscess near the coccyx, which burst open, leaving a hole that looked like a perianal fistula.
It proved, however, to have been something different. Exactly the same problem that John Arderne had encountered among knights bumping up and down in their saddles in the fourteenth century recurred some six hundred years later in a different war, again among soldiers bumping up and down on their coccyxes. This time they were not knights on horseback, but soldiers in jeeps in the Second World War. The jeep was designed for rough terrain, but had hard seats and no suspension. Tens of thousands of American soldiers spent weeks on end in hospital being treated for abscesses between their buttocks.
In such cases the infection, known as a pilonidal cyst, originates a little higher than with a perianal abscess and does not start in the rectum. The cause is not completely clear, but it always occurs in the same place, the spot where we no longer have a tail. Where our tails would have been, a small area remains after birth where the supply of blood to the subcutaneous tissue is less than ideal and there is more chance of hair growth under the skin. Some people have a small dimple in the skin at this spot. The subcutaneous hair can cause a pus-filled infection, especially if the area is continually irritated, as with the soldiers in their jeeps. For that reason, an infected pilonidal cyst is also known as ‘jeep seat’ or ‘jeep riders’ disease’.
John Arderne had not noticed that the knights’ abscesses were different from real perianal fistulas, and the distinction was not made in the seventeenth century either. King Louis, however, was certainly not suffering from a pilonidal cyst. A pilonidal cyst is not an open-ended tunnel (a fistula) but a dead end (sinus) through which Félix de Tassy would never have been able to pull his specially designed ‘fistula probe-cum-knife’. Both complaints are more common in men than women, and perianal fistulas mostly develop at a slightly later age – between thirty and fifty – than pilonidal cysts. Louis was forty-eight. Perianal fistulas can sometimes be caused by Crohn’s disease, inflammation of the bowel, but the cause is mostly unclear. In Louis’s case, the unhygienic conditions at Versailles may have played a part. Due to a lack of clean water and refrigerators, people living at the court had just as much chance as everybody else of suffering regularly from diarrhoea, caused by food poisoning. Moreover, the Sun King did not wash. He smelled so badly that once, when being visited by an ambassador, he was friendly enough to open a window himself so that his guest was not offended by his bodily odour.
Surgeon Félix de Tassy never took up the knife again after operating on the king, a fact blamed on the stress, which had allegedly become too much for him, though the generous pension, the country estate and the title he received for the operation probably had more to do with it. His ‘fistula probe-cum-knife’ can currently be seen in the Musée d’Histoire de la Médecine in Paris.
At that time surgery was not considered an honourable profession. But that was going to change. The whole of Europe heard about the royal fistulotomy. Songs and jokes appeared making fun of Louis’s fistula. Everyone was talking about it. The success of the fistulotomy exposed the lack of proficiency of doctors with their purgatives, rinses, potions and bloodletting. In the century after the royal operation, the popularity of surgeons reached unprecedented heights.
28
Electricity
600 Volts: The Electric Eel at Artis Zoo
SURGEONS WORK WITH electricity on a daily basis. Depending on the voltage, conductivity and frequency, electricity can be harmless, useful, obstructive, dangerous or lethal. On 1 March 2013, an extraordinary operation was performed in Amsterdam that clearly showed the dangers of electricity. But, the operation was not performed by a surgeon and the operating room was not in a hospital. The location was Artis Zoo and the procedure was performed by Marno Wolters, a vet who operates on a wide variety of animals.
Surgeons, of course, restrict themselves to mammals, more specifically to one species of primate, but most operations performed on Homo sapiens can also be carried out on other animals and developments in surgery help advance veterinary medicine. Neutering and spaying operations are part of a vet’s daily work, but they also perform caesarean sections on dogs, stomach operations on cows and tummy tucks on pot-bellied pigs. They repair abdominal hernias on horses, fix fractured bones on cheetahs and perform dental corrections on hippopotami.
There are surgeons who operate on the tiny stomachs and bowels in mice in the context of their scientific research, but it would be especially interesting to perform, say, an oesophageal operation on a flamingo, angioplasty on the carotid arteries in a giraffe’s neck, a pulmonary operation on a turtle, an appendectomy on a koala bear (whose appendix is two metres long), or operate on a tiger’s thyroid gland, if that were possible. How about open-heart surgery on a whale (whose heart is big enough to stand in) or a nose correction on an elephant?
The operation at Artis Zoo was no less remarkable and, with this animal, it was dangerous too. Wolters performed his operation on an Electrophorus electricus, an electric eel. The animal, which had been swimming in the aquarium at the zoo for many years, had developed a swelling in its abdomen. Electric eels are fish around one and a half metres long that have the ability to generate electric shocks, making them more dangerous than a live electric socket under water.
There is nothing extraordinary about an animal that can generate electricity. Every cell in the body continually creates an electrical field between its interior and the outside world. The voltages generated in our own bodies are very weak, but are strong enough to be easily measured. We can measure the electrical impulse of the brain, for example, with electroencephalography (EEG) or of the heart with electr
ocardiography (ECG). Nerve cells use their electrical charge to transfer signals. Our brains are an enormous regulatory centre that runs on electricity. A lot of energy is required to generate and maintain all that electricity. About a fifth of all the oxygen we need goes to our brains to supply the necessary electrical power.
The organs that an electric eel uses to generate electricity are unique. Rather than producing their electrical charges individually, they generate it in series, so that the power of the charge is cumulative. This enables the eels to produce very high voltages. As they need large quantities of oxygen to generate all this electricity, much more than a fish can extract from the water through its gills, electric eels have to come to the surface regularly to inhale extra oxygen from the air.
An electric eel has three organs that generate electricity. All three are in its tail, which accounts for almost the whole length of the fish. The Sachs’ organ emits weak electrical impulses that the fish uses as a sort of radar to feel its way through its surroundings (its eyes are very small). It is used to locate prey, which can then be paralysed by an electrical charge from the Hunter’s organ. The third, ‘main’ organ is used when the fish is in danger. It can generate a charge of 600 volts, which can immobilise any animal in the vicinity, including humans.
The abdomen of the electric eel at Artis had been swollen for several weeks and was pushing its head upwards. An electric eel’s abdomen is normally small and hardly noticeable between the head and the enormous electrical tail. Initially, the vets at the zoo thought the fish was overeating or was constipated, but reducing its food intake and administering laxatives did not help. Antibiotics also had no effect, so it was probably not an infection. It looked as though the fish had cancer. Its suffering was clearly increasing rapidly and the vets decided to examine it and see if anything could be done. That meant removing the fish from its tank, taking an X-ray and conducting a biopsy – surgically removing a small piece of the swelling and examining it under a microscope. The electric eel would obviously see all this as a threat and would use its 600-volt charges against the keepers. That would exhaust it and it would need extra oxygen. All in all, it was a risky undertaking not only for the humans, but also for the fish itself. The operation therefore had to be carefully prepared.
It was not the first operation on an electric eel. Artis contacted vets in Chicago who had performed the same procedure in 2010. Preparations were made and summarised in a log. It was important to know that an electric eel only emits an electrical charge when it wants to, so never unconsciously. That meant that it would not emit charges if it was asleep – and that had two advantages. Once the fish was under anaesthesia, the operation could be performed without fear of electric shocks. Secondly, the depth of the sleep could be measured simply with a voltmeter in the water. The weaker the charge, the better the anaesthetic was working.
The operation was performed in the gallery behind the large hall of the zoo’s historical aquarium. Everyone wore special electrician’s gloves, the two keepers responsible for catching and moving the fish even wore rubber diving suits, and the operating table was made from a piece of PVC guttering, in which the fish could be laid for the X-ray and the biopsy. Using a net, the fish was transferred to a plastic tank full of water, through which extra air was pumped. The electric shocks were measured with a simple voltmeter, while the anaesthetic (Tricaine) was added to the water. Over the course of an hour, the intensity of the shocks diminished and the fish’s movements decreased.
Once it was fully asleep, it was lifted out of the water and placed in the gully-shaped operating table. The voltmeter showed no more electric charges. The fish’s mouth was continually rinsed with the Tricaine solution. The size of the swelling was now clearly visible and hard lumps could be felt in the swollen belly. An X-ray was taken and, wearing his rubber gloves, Wolters made a small incision in the skin above the tumour. An electric eel does not have scales, but skin similar to that of a real eel, which made Wolters’s job easier. He removed a small piece of tissue from the abdomen and stitched the wound up with absorbable thread. With fish, it is important to use a suture that does not dissolve too quickly. A wound will heal within two weeks in a warm-blooded animal but fish, which are cold-blooded, have a much slower metabolism. So a suture has to remain in place for six to eight weeks to ensure that the wound heals properly. After the small operation, the fish was placed in a tank of fresh water to come around. It soon started to move again and the first shocks immediately registered high voltages.
Around an hour later, however, there was clearly something wrong with the electric eel. The shocks were no longer regular and it became less active. Then, suddenly, it emitted a single high-voltage electrical discharge and stopped moving completely. The fish was dead. It was as though it had exhaled its final breath in the form of electricity. Had the anaesthesia and the operation been too stressful, or had the cancerous tumour proved too great a burden for it to endure?
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Sutures
Sutures are performed using a special tool called a needle holder, in which the needle is tightly clamped. A right-handed surgeon holds the needle holder with the thumb and ring finger of his right hand. In his left hand, he holds tweezer-like forceps to lift the tissue and take the needle over from the needle holder. Suture needles are curved, so that the tissue is manipulated as little as possible during stitching. They are disposable needles to which the suture thread is already attached. The needle and thread come in double-layered sterilised packaging. The outer layer can be opened without touching the inner layer. The operating surgeon or his assistant can then take hold of the inner packaging without touching the outer layer. This ensures that no bacteria are passed on when the surgeon is handed the needle. There are sharp needles, blunt needles, cutting needles, and large and small needles. There are absorbable and non- absorbable suture threads, threads made of one piece and others that consist of several threads woven together. All of these combinations of different threads and needles are packaged separately and with threads of different thickness and strength. The strength of the thread is expressed with a number. Number 1 is quite thick, 2 is very thick, and so on up to 5. A 0 thread is finer, but most threads are even thinner. They are indicated by a series of zeros. Two-zero thread (00) is thinner than 0. Three zeros (000) is a normal thickness for a skin suture. Blood vessels are stitched using very thin six-zero thread while threads with 12 zeros – thinner than a human hair – are used in microsurgery.
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Wolters conducted an autopsy on the cadaver. The tumour was gigantic and had spread to the liver and the spleen. Microscopic tests later showed that it was metastatic pancreatic cancer. That explained the rapid growth of the tumour. The fish’s prospects would have been very bleak, in any case. Perhaps, by dying after the anaesthesia, it had been spared a lot of suffering.
The electricity that Wolters and his team had to take into account was unpredictable. Surgeons (who operate on people) also have to be aware of the dangers of electricity in their daily work, but fortunately the amount of electricity in an operating room can be regulated and controlled. Electricity is present everywhere during an operation. The anaesthetist’s respiratory machine and the instruments that monitor the heartbeat, oxygen level and blood pressure run on electricity. The operating table needs electricity to move, the lights are of course electric, the equipment used for keyhole surgery depends on electricity, the mobile X-ray machines produce kilovolts of electrical charge, and there are computers in the operating room to record and retrieve medical data and video monitors to watch procedures and look at X-ray photographs – all of which are electrically driven. And there are also some operative methods that require electricity, much closer to the patient and the operating staff than you might expect in such a safe situation. For example, almost no operation can be performed in modern surgery without electrocoagulation. This is applied using a kind of electrical knife evolved from a combination of a scalpel and a branding iron. During e
lectrocoagulation, the patient is literally ‘live’. And yet it is safe.
In the Stone Age, surgeons used stones. Abraham of Ur used a stone knife to perform circumcisions. The Greeks used scalpels of bronze, the Romans used iron and we use steel. In the past hundred years, thanks to technological developments, new types of knife have been devised. Piezoelectricity (well known from the sonar systems in submarines) is applied during operations in a special instrument that uses vibration to dissect and to stem bleeding. Not long after the power of radiation (nuclear power) had been harnessed, gamma rays were used in surgery with a tool known as a gamma knife. Shortly after the development of usable microwaves (e.g. for cooking), the technique was also introduced in surgery, and the same applies to lasers. But the most successful instrument of all remains the simple electric scalpel, which was introduced into surgery shortly after the widespread introduction of electricity into daily life (the electric light bulb).
Experiments with using electric filaments to stem surgical bleeding by cauterisation (known as electrocauterisation, from the Latin word cauterium, branding iron) were conducted as early as 1875. The filament was, however, much too hot and cauterised the surrounding tissues in a much wider area than was intended. It was slow and imprecise, not to mention dangerous.
Under the Knife Page 28