Next came the ophthalmologists with their immensely successful intraocular lens implant for cataracts which, along with Charnley’s hip replacement, became one of the great ‘mass’ operations, tens of thousands being performed every year. In 1948 Harold Ridley, ophthalmic surgeon at St Thomas’s Hospital, had a flash of inspiration when a student remarked, after observing him remove a cataract: ‘It is a pity the lens cannot be replaced by an artificial one.’ Ridley was stimulated by this apparently naive remark to recall his experience from a few years earlier when treating eye injuries in fighter pilots during the Second World War. To his surprise, the fragments of glass from the aircraft’s shattered windscreens that had pierced the eyes had caused little damage. Perhaps, Ridley speculated, the eye was some sort of ‘privileged sanctuary’ that could tolerate foreign objects such as splinters of glass. If so, it would indeed be possible to replace the lens clouded by cataract with a plastic one. His review of his first twenty cases two years later was modestly optimistic, though he did note that ‘in some the persistence of exudate on the lens surface still partially obstructed vision, but it is not beyond hope that all will become clear in due course’. His medical colleagues took a different view, as his former house surgeon observed: ‘It needed great fortitude to face up to the loud criticisms of his colleagues and the frank disbelief at his results.’6
Ridley’s very high failure rate discouraged others, but the advent of the Zeiss operating microscope in the 1950s and a newer, lighter implant improved results dramatically. ‘Without the Zeiss microscope, ophthalmic surgery as it now is would be unimaginable’, – not just cataracts, but operations for the relief of glaucoma, for detachment of the retina and on ‘the vitreous’, the jelly-like substance that maintains the shape of the eyeball.7
The operating microscope would also prove indispensable for operations involving very small blood vessels, as already described, massively extending the range of three further specialties: neurosurgery, plastic surgery and the replantation of amputated limbs. The first successful replantation operation was performed in Boston in 1962 on a twelve-year-old boy, run over by a train which completely amputated his arm. Eight years later he was arrested by the police ‘after using his replanted hand to steal from a store’. The Chinese became particularly adept at this type of surgery, with a report from Shanghai’s Sixth People’s Hospital of the first hand replantation in 1963 on a 27-year-old man who subsequently went on to become a table-tennis champion.8
In neurosurgery, the repair of bleeding blood vessels and aneurysms in the brain had always carried a very high mortality rate, but there was not a single fatality in the first forty repairs done with the aid of the operating microscope. ‘The importance of the introduction of magnification has completely changed virtually all procedures done within the specialty’.9
Finally, in plastic surgery, microsurgery revolutionised skin grafting for severe burns, replacing the standard technique devised by Sir Harold Gillies in 1917, when confronted with the problem of reconstructing the face of a sailor severely burned in the Battle of Jutland. ‘This poor sailor was rendered hideously repulsive and well nigh incapacitated by his terrible burns. The structure of the nose, lips, eyelids, the ears and neck were burnt and his hands were contracted into frightful deformity. How a man can survive such an appalling burn is difficult to imagine until one has met one of the survivors from such a fire and realised the unquenchable optimism which carries them through almost anything.’ Gillies dissected a skin graft out from a donor site on the sailor’s chest except for one end – ‘the pedicle’ – and then rolled it into a tube, swung it in the direction of the burns on the face and reattached it. The graft’s blood supply was maintained by the pedicle until the replanted end had acquired its own blood supply, at which point the graft could then be separated from the pedicle, the tube unrolled and used to cover the mouth and nose.
Gillies was the ‘father of plastic surgery’ and he trained the following generation just in time for the next major conflict to produce horrifying burns – the Battle of Britain, in 1940. British pilots tumbled out of the air over Kent and into beds at East Grinstead Hospital under the care of one of Gillies’s pupils, Sir Archie McIndoe. There they became one of McIndoe’s ‘guinea pigs’, so called out of respect for the surgeon under whose care they sometimes remained for two years. Twenty or more separate operations were sometimes necessary, in which pedicles were swung from the arm and shoulder and chest upwards to the face to repair its ravaged appearance. The result was never perfect, though with the passage of time it became more acceptable.10
Then, quite suddenly, in 1972, these techniques became redundant with the first report of a microsurgical ‘free skin flap transfer’. Instead of raising a ‘tube pedicle’ and waiting for it to acquire a new blood supply, the full thickness graft was taken from a part of the body that could afford to lose it – which in the first reported case was the groin – and transferred to the site requiring grafting, the ankle. The minuscule blood vessels of the graft were then connected – with the aid of the operating microscope – to those of the donor site, the arterial clamps were removed and ‘there was immediate perfusion of the graft as evidenced by its colour. After 17 days the sutures were removed and a few luxuriant pubic hairs were noted growing on the ankle. The donor site had completely healed.’11 The significance of this development scarcely needs to be spelled out as two years of surgery involving up to twenty operations were telescoped down into one procedure.
In summary, the Zeiss operating microscope transformed the practice of ENT, ophthalmology, neurosurgery and plastic surgery. Simultaneously the endoscope, by allowing the visualisation of the internal structures of the body, was having a similar effect on an entirely different range of specialties, including gynaecology, orthopaedics and abdominal surgery.
The Endoscope
There are many ways of ‘seeing’ beneath the skin to find out what is amiss in the inner recesses of the body, from the simple chest X-ray to the total-body CT scan, but if the intention is not just to see but also to do something, such as cauterising a blood vessel bleeding into the stomach, then there is no alternative other than to use an instrument through which the site of the bleeding can be seen with the human eye and down which a cauterising device can be passed. These instruments are known as ‘endoscopes’, derived from the Greek prefix endo – ‘within’ – and the verb skopein – ‘to observe’ – not merely in the sense of ‘looking at something’ but also to ‘observe with intent’.
There are two types of endoscope, each with its own optical requirements. When the intention is to ‘observe with intent’ a hollow organ such as the stomach, colon or bladder, the endoscope must be fully flexible, able to look in all directions and contain an aperture down which a biopsy forceps or a cauterising device can be passed. When, however, the intention is to inspect a closed cavity such as the abdomen to perform some procedure on the female reproductive organs or the gut, then a rigid endoscope is required down which instruments can be passed and whose optics must be of such high quality that it is possible to see what is being operated on with great clarity.
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 fo
r 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.’12 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.13
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.14 ‘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.15
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.16 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.17
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 Rise and Fall of Modern Medicine Page 24
