The Rise and Fall of Modern Medicine (33 page)

The origins of both types of endoscope stretch back to the late nineteenth century, but they never achieved widespread use because their optical systems were deficient. Thus the gastroscope for inspecting the inner lining of the stomach was only ‘semi-flexible' so only a partial viewing could be obtained, while the visualisation of the inside of the abdomen as seen down the laparoscope was much too poor to permit any sort of operative intervention. And that was the situation until Harold Hopkins – a lecturer at Imperial College in London – solved both problems, first with the fully flexible fibreoptic endoscope in 1954 and then five years later with the Hopkins rod-lens system, which improved the quality of the laparoscopic image eighty-fold.

Harold Hopkins was born in 1918, the son of a Leicester baker. After graduating in physics and mathematics in 1939 from the university of his home town he worked briefly for a firm of optical instrument makers. He spent his war years as a scientific research officer attached to the Ministry of Aircraft Production and in 1947 joined the staff of Imperial College, London, where he stayed for twenty years before moving to Reading University as Professor of Applied Physics. ‘Harold Hopkins was an outstanding physicist, he had a fertile mind, steely determination and ferocious curiosity. His intellect was motivated by a constant
belief in the power of fundamental physics.'
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Regrettably it is not possible to describe precisely how Hopkins came to make his two remarkable contributions as the details are too technical. So, the following account describes the events leading up to, and the many consequences of, his astonishing achievements.

At a dinner party in 1951 Hopkins found himself sitting next to Hugh Gainsborough, a gastroenterologist from St George's Hospital, who complained to him about the ‘inadequacies' of the gastroscopic instruments then available. Even the most sophisticated, the semi-flexible gastroscope, he told Hopkins, required great skill and expertise, caused considerable discomfort to the patient and the field of vision was limited, leaving ‘blind spots' at the apex of the stomach and at the entrance to the duodenum. This seriously limited its diagnostic usefulness and the doctor could never be entirely sure that he had not ‘missed something' to account for the patient's symptoms. What was needed, suggested Dr Gainsborough, was a gastroscope whose tip could be manipulated in several different directions so that the lining of the stomach could be visualised in its entirety.

Reflecting on this problem, Hopkins, it would seem, was reminded of an experiment conducted by the great Victorian scientist John Tyndall, who showed that light, which usually travels in straight lines, could, in special circumstances, go round corners. In 1870, at a demonstration held before the Royal Society in London, Tyndall used an illuminated vessel of water to show that when a stream of water was allowed to flow through a hole in the side of the vessel, light was conducted along the curved path of the stream. This effect can be simulated with curved glass. Indeed glass-blowers in Ancient Greece and Renaissance Venice constructed beautiful glass objects made of thin cylinders, along which light could be conducted from a lamp beneath with magical effect.

Hopkins speculated that if tens of thousands of very narrow flexible glass fibres were collected in a bundle they should be able to transmit light round corners, and whatever was illuminated should be transmitted back up the bundle to be viewed by the observer. He spent three years on the project, publishing the details in
Nature
in January 1954. So was born the fibre optic endoscope.
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Hopkins, as an optical physicist, was not in a position to apply the principle of fibreoptic endoscopy for medical use, but a young South African, Basil Hirschowitz, a research fellow in gastroenterology at the University of Michigan who was ‘frustrated at the inadequate visualisation and difficulty' of the gastroscopes in use at the time, read Hopkins's article in
Nature
and immediately arranged a vacation. He flew to London to see Hopkins at Imperial College, finding him ‘warm and friendly and most modest and generous'. Hopkins's instrument was very much a prototype, being less than a foot long and thus quite unsuitable for practical use, but ‘the definition was good enough' so Hirschowitz returned to the United States to turn it into a practical instrument.
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‘The apparatus for making the glass fibres was assembled from odds and ends in the physics department – no more than $250 being spent on the equipment. The principle was to melt the end of a vertically held rod of glass in an eight-inch-long tubular furnace to draw out a fibre from the smelt.' The fibre was then wound on to a drum (originally a circular 2lb box of Mother's Oats), with 200,000 fibres having to be oriented so the ends were exactly the same and stayed that way. This was difficult and very time-consuming work posing many technical problems, the most insuperable of which was ‘cross talk' – when two fibres are in close contact, light jumps from one to the other, which causes the image to be lost. Somehow the glass fibres had to be insulated from each
other, a problem solved by Hirschowitz's collaborator Larry Curtiss. ‘When he first proposed to melt a rod of optical glass inside a tube of lower refractive index glass and pull the two together into a composite fibre, all the wise men in the physics department laughed at him. Fortunately he persisted and produced the fibre on which today's fibreoptics is based – a glass-coated glass fibre.' Dr Hirschowitz's first view of the potential of Larry Curtiss's method of insulation was ‘on a dark late December afternoon when a single fibre was used to transmit a white spot of light 25–30 feet from one room into the next. We knew that the problems of insulation and excessive light loss were solved. From then on it was purely a matter of applying and developing the process – we were home free.'

Within six weeks Dr Hirschowitz had the first modern fibreoptic gastroscope in his hands. ‘I looked at this rather thick, forbidding but flexible rod, took the instrument and courage in both hands and swallowed it over the protest of my unanaesthetised pharynx.' Within a few days he had passed the instrument into his first patient, the wife of a dental student with a duodenal ulcer. The new gastroscope was everything and more that Hirschowitz could have hoped for, rendering the conventional semi-flexible gastroscope ‘obsolete on all counts'. The illumination was two and a half times better and the whole of the inner lining of the stomach could be visualised.

Hopkins's fibreoptic instrument changed the practice of medicine in multiple ways, falling into two categories – the diagnostic and the therapeutic. With the fibreoptic endoscope, the doctor could travel much further and deeper than ever before into previously uncharted territory. Thus the gastroscope not only visualised the lining of the stomach but could be passed through the pylorus into the duodenum, which in turn gave access to the pancreas and biliary system. Coming from the
other end, the fibreoptic colonoscope could be manipulated all the way up the colon to a site where it joins the small intestine. The furthest reaches of the lung and bladder became equally accessible. The technique of using the endoscope was readily acquired and so it could be used in a routine way to investigate the cause of any symptom that might arise from any of these structures. Bleeding from the gut, for example, could be investigated by the most reliable and direct means – inspecting the lining to identify what was amiss. Further, once the bleeding was identified it could be biopsied and the tissue examined under the microscope, permitting an accurate diagnosis that would then have a major influence on treatment.

The difference that fibreoptics made to improving the accuracy of diagnosis was paralleled by its therapeutic potential, permitting, for example, a bleeding artery in the stomach to be cauterised or a polyp in the colon to be ensnared without the need for major surgery.
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Hopkins's second optical innovation came in 1957, six years after the dinner party that had led to the fibreoptic endoscope. This time, however, Hopkins was sought out by a Liverpool urologist, Jim Gow. During the war Gow had served in the North African campaign, which culminated in the Battle of El Alamein. Among the German booty seized by the victorious Allied forces, he spotted a Leitz cystoscope, a metal instrument for examining the interior of the bladder, which he appreciated was the most sophisticated of its kind in the world. Gow duly appropriated it, in anticipation of specialising in urology once the war was over. Gow's main hobby was photography, which he combined with his professional work as a urologist by taking photographs of the bladder through the appropriated Leitz cystoscope as an aid to diagnosis, particularly for documenting the response of tumours to treatment.
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Regrettably the results were
not very satisfactory: ‘It was apparent after many attempts that not only was the optical system inadequate but also the illumination was insufficient.' Jim Gow turned for help to the physics department at Liverpool University, who suggested he should contact Harold Hopkins in London.

Though initially reluctant, Hopkins agreed to evaluate the optics of the Leitz cystoscope and calculated that ‘the transmission would have to be increased by a factor of fifty-fold to obtain enough light' for Jim Gow's purposes. The most that could be hoped for from design refinements of the instruments currently in use was a two-fold improvement. Clearly if the difference was to be bridged the whole optical system of rigid endoscopes would have to be considered.

The Leitz model contained along its shaft a group of lenses every few centimetres, acting as a relay system, conveying the image down the barrel to the eyepiece where it was magnified. Hopkins decided to turn these conventional optics on their head. Rather than an endoscope consisting of a tube of air interrupted by thin lenses of glass, his contained a tube of glass, interrupted at intervals by thin lenses of air. The Hopkins rod-lens endoscope had a total light transmission eighty times greater than the Leitz system it replaced. Now Jim Gow's photographs of the interior of the bladder had the same clarity as any conventional photograph taken outdoors on a sunny day.
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And with such a brilliant view, suddenly it was obvious that there was much more that could be done down an endoscope than just the taking of photographs. In particular the laparoscope inserted into the closed cavity of the abdomen would, like the fibreoptic endoscope, obviate the need for many forms of surgery. First a small incision is made in the abdomen, just below the umbilicus, through which the laparoscope is slipped. The surgeon or gynaecologist then starts to look around to
identify different organs – the ovaries, the fallopian tubes, the liver, the small intestine and so on. Having identified the structure he wishes to operate on, he then passes instruments down through the laparoscope and the patient is saved from what would previously have been a major operation.

The gynaecologists were the first to appreciate the potential of the new approach. In Germany Kurt Semm at Kiel saw the virtue of the new procedure for women seeking sterilisation having completed their families, passing an electric cauterising device down through the laparoscope that he used to close off the fallopian tubes. Over the next twenty years he performed the full range of gynaecological operations down the laparoscope, treating ectopic pregnancies, ruptured ovarian cysts and injured fallopian tubes.
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In Britain, Bob Edwards's collaborator Patrick Steptoe used the laparoscope, as already described, to obtain maturing eggs from the ovary, which, once removed and fertilised, made possible the birth of the first test-tube baby.
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The influence of the laparoscope on surgery of the gut and liver came about more slowly. In 1983 the first gall bladder was removed through the laparoscope, transforming an operation that previously involved a major abdominal incision and ten days of convalescence into a ‘day surgery' procedure. Three years later a computer chip television camera was attached to the end of a laparoscope, inaugurating the era of ‘keyhole' or ‘minimally invasive' surgery. As with gynaecology, a wide range of operations that previously required open incisions in the abdomen – hernia repairs and the removal of malignant growths and parts of the spleen, stomach and colon – could now be performed so expeditiously and with so little trauma that the patient could often return home the same day.
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And so it went on. Orthopaedic surgeons used the endoscope to look inside and repair traumatic injuries, especially to the
knee and shoulder.
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ENT surgeons found that chronic sinusitis could be cured by improving the circulation of air with an operation through an endoscope at the back of the nose.
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Even the removal of a kidney, which previously left a vast scar in the flank, could now be performed endoscopically.
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Harold Hopkins was a genius. The impact of his modern endoscopes – along with the operating microscope – is clearly very important in its own right, but also illustrates the cardinal feature of the technological contribution to post-war medicine. Surgeons had, it is true, been practising various forms of endoscopy since the turn of the century, but it remained a province of a few enthusiasts and the results were unreliable. Hopkins's two optical innovations meant that now anyone could become an endoscopist, so the number of patients who could benefit increased vastly. The contribution of technological innovation has thus been not only to enlarge the scope of medical intervention, but also, by simplifying the complex, to enlarge its range as well. This, as will be seen, can be something of a two-edged sword.
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