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The Rise and Fall of Modern Medicine

Page 40

by James Le Fanu


  ‘The line is advancing’, and the verdict in ‘Technology’s Failings’ of technology being ‘out of control’ needs revising. The three illustrative examples of ‘The Misuse of Diagnostic Technology’, ‘Foetal Monitoring’ and ‘Technology and the High Cost of Dying’ might be in their different ways undesirable – but they now seem more a regrettable consequence of, rather than intrinsic to, technology’s potential to alleviate the problems of disease. That verdict also conceals how technical developments such as keyhole surgery have ‘democratised’ medical interventions by making them available to the ever greater number of those who might benefit from them. Much of surgery, for example, is essentially an exercise in applied engineering, constrained only by the vulnerability of the (ageing) tissues and organs of the body to the trauma of the procedures involved. Change that, make those procedures simpler or less traumatic, then the numbers for whom such interventions are deemed appropriate will rise remorselessly. It would seem appropriate to consider in rather more detail the three major developments that have allowed doctors ‘to do so much more’. They are coronary angioplasty (the dilation of narrowed blood vessels to the heart), minimally invasive (or keyhole) surgery, and the dramatic shift towards performing major surgery in those in their eighties and beyond.

  Coronary Angioplasty

  The circulation of the blood, as first demonstrated by William Harvey in 1626, remains the unifying principle of physiology. Compromise that circulation by narrowing or blocking an artery, then whatever organ it serves, particularly the heart or brain, will be relatively (or absolutely) deprived of the life-sustaining oxygen carried in the blood – with the predictably adverse consequences of a heart attack or stroke.

  It is, of course, possible to restore the circulation to the heart with a Coronary Artery Bypass Graft but it would be so much less intrusive and more elegant to do so ‘internally’ by introducing, for example, a wire or catheter into the artery so as to dilate the obstruction from within, ‘like a footprint in the snow’. The origin of this most potent form of medical technology begins back in 1964, when an 82-year-old woman, Laura Shaw, was admitted to the University of Oregon Hospital with a non-healing ulcer and gangrenous toes of the left foot due to a blockage of the major femoral artery in her leg. Her physicians advised that, in view of her age, her best option would be to have the leg amputated – which she steadfastly refused. The Professor of Radiology at the hospital, Charles Dotter, a self-confessed ‘inveterate doer and fiddler’, suggested instead that the narrowed segment of the artery might be dilated in the manner just outlined. This was duly carried out, causing her cold pale limb to become once more warm and functional. Over the next few weeks the ulcer and gangrenous toes healed – and remained so till her death from pneumonia two and a half years later.2

  This type of procedure is now so commonplace as to verge on the banal, but when Charles Dotter described its wider possibilities to a medical conference, anticipating its many subsequent applications, he received a standing ovation. ‘For those of us in the audience’, as one of those present subsequently noted, ‘it was like a bomb had been dropped.’3

  The blood supply to the heart, the coronary arteries, are a rather different proposition. The prospect of restoring the circulation ‘from within’ is not only technically much more complex but would reasonably be interpreted as asking for trouble as the introduction of a wire or catheter carries the risk of critically reducing the already compromised blood supply to the heart, to cause precisely the problem that it is intended to prevent. Further, it would require a complete redesign of Charles Dotter’s original catheter to create a balloon at the end capable, when dilated, of exerting sufficient force against the wall of the artery to dilate the obstruction. To this end a German cardiologist, Andreas Gruentzig, transformed his kitchen into a small laboratory where, with the help of his wife, he would fashion numerous versions of the balloon catheter with tiny bits of rubber, thread and epoxy glue.

  First time round, he was unable to manoeuvre the catheter into the narrowed artery, following which his patient had a further major and lethal heart attack. His medical colleagues were not impressed and a further year would elapse before his second attempt, on a 38-year-old insurance salesman crippled by severe angina due to a single obstruction of his main left coronary artery.

  On 16 September 1977, Gruentzig recalled:

  The Chief of Cardiology, the cardiac surgeon, anaesthesiologist, and the radiology fellows were all in the operating room to observe the procedure. The guiding catheter was placed in the left coronary orifice and the dilating catheter was inserted. Everyone was surprised by the ease of the procedure – there was no ventricular fibrillation and the patient had no chest pain. I started to realise that my dreams had come true . . .4

  Andreas Gruentzig, with this single manoeuvre, substituted the procedure of a standard coronary artery bypass graft – with its requirement to split the chest open to gain access to the heart, link it up to ‘the pump’, and harvest veins from the legs to bypass the obstruction, followed by a lengthy convalescence – with another, the coronary angioplasty that can be performed under local anaesthetic, permitting the patient to be discharged from hospital the following day.5,6,7

  This led in turn to the logical, if yet more audacious, proposal of further deploying coronary angioplasty not just to dilate narrowed arteries but as an emergency procedure in the early stages of an acute heart attack, to prevent damage to the heart muscle with its potentially lethal consequences. The rationale is simple enough: theoretically it should be possible to ‘recanalise’ a coronary artery blocked by a clot or thrombus, thus restoring the blood flow before it has caused too much damage to the heart muscle.8

  But the logistical problems are (as can be imagined) considerable, for the procedure must be performed within half an hour of the onset of symptoms to have any chance of success. This requires a ‘system’ of transferring the patient to a specialised unit continuously staffed by doctors with the requisite skills, able to respond rapidly if and when (as is inevitable with such a potentially high-risk venture) ‘things go wrong’. The practicalities of combining the necessary speed with the appropriate skill, competence and back-up are prodigious – but perhaps epitomise the success (indeed triumph) of modern medicine in their ability to ‘routinise’ life-saving procedures in the most potentially dangerous of circumstances.

  Thirty years on, cardiologists in the United States now perform a million coronary angioplasties every year, which have become technically ever more sophisticated with the insertion of ‘stents’ coated with chemicals to prevent the artery from becoming narrowed again. The significance of this type of procedure in permitting doctors to ‘do more’ is captured in a single statistic. Over the past decade, the number of coronary angioplasties in those aged eighty or more has increased twelve-fold.9

  Through the Keyhole

  The techniques of keyhole or minimally invasive surgery rank as the single most radical development in surgery since the introduction of anaesthesia in the nineteenth century. It all began, as will be recalled, with the imaginative genius of the English physicist Harold Hopkins, who devised the sophisticated optical systems of the fibreoptic endoscope and the laparoscope. Together, as set out in ‘Technology’s Triumphs’, these two ‘scopes’ would transform the practice of modern medicine, where procedures that previously required a major operation are now performed routinely through the narrow steel tube of the laparoscope: for abdominal surgery – removing gall bladders, resecting the colon, repairing hernias; for gynaecology – removing fibroids, performing hysterectomies, pelvic floor reconstruction, sterilisation and IVF; for urology – repairing the neck of the bladder, removing the prostate gland and diseased kidneys; and orthopaedics – arthroscopic surgery for damaged and arthritic joints and prolapsed discs; and much else besides. The ascendancy of keyhole surgery is the more impressive, for while these procedures are certainly ‘simpler’ for the patient in minimising the trauma and allowing fo
r a much more rapid recovery, they are technically vastly more complex than the methods they have replaced.

  ‘[Keyhole] surgery carries significant disadvantages,’ writes Andreas Melzer of the University of Dundee.

  The remote nature and restricted access leads to intra-operative problems such as the lack of tactile feedback due to the loss of direct handling of tissue which is crucial for the evaluation of local anatomy and pathology. The more serious problem emanates from the difficulties of appropriate and efficient haemostasis [control of blood loss], the localisation of the bleeding point is often impaired by surrounding tissue . . . the use of swabs being restricted due to [poor] access.10

  Nonetheless the ascendancy of both fibreoptic and laparoscopic surgery over the past twenty-five years is immensely impressive. In Britain, they now account for four of the ten most frequently performed surgical procedures, where over the past two decades, the number of arthroscopies has gone up eight-fold (up from 15,000 to 117,000), while the number of endoscopic operations on the bladder has doubled from 123,000 to 289,000.11,12

  Many of these procedures are relatively straightforward – such as inspecting the internal lining of the gut or bladder to identify a source of bleeding. But the implications for ‘advancing the line’ are illustrated by the astonishing technical feat – first performed in 1990 – of removing the colon (the laparoscopic colectomy) in those with cancer or inflammatory conditions such as diverticulitis. Many of those requiring these operations are elderly and debilitated by other chronic illnesses, thus the keyhole approach has an obvious appeal. The technical complexities, as can be imagined, are daunting: not just cutting out the diseased segment of the bowel, but stapling the two free ends back together again, not to mention ensuring that vulnerable structures in close proximity such as the ureters draining urine from the kidneys to the bladder are not damaged. These problems are compounded for those with cancer by the need to ensure that the tumour is removed in its entirety, along with any lymph nodes to which it may have spread.13,14

  Yet ten years on surgeons could report the average hospital stay for this procedure in those over the age of eighty had fallen to a mere two and a half days – with full resumption of normal bowel function. And, contrary to the previous misgivings that the keyhole approach would compromise the survival prospects of those with cancer, subsequent experience has revealed no difference in local or distant recurrence when compared with ‘open’ surgery.15,16

  Nor has this drive towards less pain, minimal scarring, fewer complications and faster recovery reached its limits. Professor of Surgery at Washington University Richard Sataba insists rather that laparoscopic surgery is still ‘a transitional technology’: ‘Its instruments remain awkward, bulky, imprecise, limited in performance by the direct forces applied by the surgeon’s hand and arm.’ These limitations, he anticipates, will be overcome by ‘intelligent’ instruments that are ‘more precise and dextrous’, thus extending the surgeon’s skills ‘beyond the physical limits of human performance’.17

  Too Old for What?

  Notwithstanding the technical virtuosity of coronary angioplasty and keyhole surgery, the most significant impetus behind the medical expansionism of the recent past has been a major psychological shift in perspective – the increasing recognition by doctors and the public there are no longer, in principle, any age limitations to surgical intervention.

  The origins of this dramatic shift can be traced to the publication in 1993 of an article in the prestigious New England Journal of Medicine under the heading ‘Too Old for What?’18 This ‘exercise in clinical problem-solving’ concerned an ‘independent and active’ 87-year-old woman with no known heart or pulmonary problems who consulted her physician with increased breathlessness. This, it transpired, was due to a combination of a tight narrowing of the aortic valve (aortic stenosis) together with severe narrowing of the coronary arteries – that on the left being completely blocked and with a 90 per cent narrowing on the right. It was, in short, astonishing she was still alive. There was no alternative – if something was to be done – other than to perform open heart surgery to both replace her aortic valve and also bypass those obstructed coronary arteries. This was duly carried out, following which she developed kidney failure, the rapid irregular pulse of atrial fibrillation, wildly fluctuating blood pressure, congestive heart failure and depression. Five months later, she was back home and ‘had resumed an active social schedule’ with, it was pointed out, a further life expectancy of at least five years – for most of which she could anticipate being ‘without cognitive or physical impairment’. So while there are obviously substantial risks associated with heroic surgery at this age, ‘notably, those who do survive are likely to live as long as their healthy peers’. Thus, a person’s age might be ‘an important piece of information’, but ‘the patient and doctor together must decide what is “too old”’.

  The editor of the New England Journal was sceptical. The outcome for most 87-year-olds, he argued, could well be very different – culminating in a ‘protracted debilitating and dehumanising stay in the intensive care unit’ without their ever returning to ‘an active social schedule’. This would give a rather different gloss to the proposition that major heart surgery was appropriate at the ‘extreme of life’.

  But the die was cast. In the aftermath of ‘Too Old for What?’, the question ‘Should We?’, when confronted by the dilemma of whether or not to replace the aortic valve in an ‘independent and active’ 80-year-old, rapidly became ‘Why Shouldn’t We?’. Ten years later cardiac surgeon Matthew Bachetta of the New York Presbyterian Hospital would raise the ante: over the previous decade he had operated on forty-two nonagenarians with an average age of 91.4 years, of whom thirty-eight had survived on average two and a half years after surgery. His review of the statistics of cardiac surgery in the elderly stretching back over the previous thirty years revealed a fascinating pattern where every decade the ‘maximum age’ for the procedure had also risen by a decade – from seventy in the 1970s to eighty in the 1980s to ninety in the 1990s. In each instance the initial high mortality rate in the immediate aftermath of surgery of around a quarter had, with greater experience, fallen to around 7 per cent. And the further the boundaries were pressed, the greater the number who might (theoretically) benefit from this type of surgery – where almost one in ten nonagenarians have narrowing of the aortic valve of such severity as to warrant surgery.19

  The following year, in 1994, Raymond Tesi of the University of Ohio would add a further important and unexpected twist in his review of kidney transplants in the elderly.20 The risk of failing kidneys is strongly age-determined – in the United States, 14,000 people over the age of seventy-five are now on dialysis – but the definitive treatment of a kidney transplant is constrained by two considerations: firstly that younger patients are, by definition, more likely to benefit for longer from the limited number of available kidneys, and secondly it would be reasonable to suppose that the complication rate from rejection of the transplanted kidney and similar problems is likely to be considerably higher. Yet Professor Tesi’s review revealed the precise opposite – that the chances of rejection lessened with age. Specifically, just one in ten of those over the age of sixty experienced an ‘immunologically induced kidney graft loss’ compared to one in three of the younger patients – which one might reasonably attribute to the probability that an ageing immune system is more likely to tolerate a transplanted organ. And if that is the case, then the same should apply for those requiring liver transplants. (It does.) So, yet again, ‘the line has advanced’, with thousands of those with kidney failure who previously would have been discriminated against on the basis of age becoming candidates for transplantation.

  It is scarcely necessary to reiterate the profound significance of these events not just on their own account but more generally, where the extrapolation of the benefits of interventions such as cardiac surgery and kidney transplants to (virtually) all major medical interventions
exemplifies how the inevitable vicissitudes of ageing have become only so many medical problems warranting a technical solution – which, in the progressively ageing populations of Western nations, must inevitably result in the cost of health care spiralling upwards.21

  2

  THE NEW GENETICS TRIUMPHANT –

  OR NOT

  The fortunes of the New Genetics, the driving force of biomedical research over the past three decades, are obviously central to any analysis of the current state and future prospects of medicine. Here the verdict of just over ten years ago that ‘despite all the enthusiasm and excitement, the tens of thousands of scientific papers and acres of newspaper coverage, its practical benefits are scarcely detectable’ seem rather premature. There are numerous instances where many years may pass before the full realisation of some major scientific development. Famously, nearly 300 years elapsed between William Harvey’s description of the circulation of the blood in the seventeenth century and its practical application in the form of cardiac surgery. Why should the New Genetics be any different?

  And, as if to emphasis the prematurity of that verdict, the completion of the first draft of the Human Genome Project (HGP) in the year 2000 could scarcely have been more propitious. The truly astonishing ability to spell out the full sequence of human genes signposted the way towards an ever profounder understanding of human biology and the phenomena of illness.1 The announcement, at a full press conference in the White House Presidential Office, was suitably impressive: ‘Nearly two centuries ago, in this room, on this floor, Thomas Jefferson spread out a magnificent map . . . the product of a courageous expedition across the American frontier all the way to the Pacific,’ President Bill Clinton declared. ‘But today the world is joining us here to behold a map of even greater significance. We are here to celebrate the completion of the first survey of the entire human genome. Without a doubt this is the most important, most wondrous map ever produced by mankind.’

 

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