Disease processes and diagnostic techniques 1

1. and the mechanisms of surgical disease 3 DISEASE PROCESSES 2. Managing physiological change in the surgical patient 9 3. Immunity, infl ammation and infection 27 4. and resuscitation 52 DIAGNOSTIC TECHNIQUES 5. Imaging and interventional techniques in surgery 59 6. Screening for adult disease 88

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A SHORT HISTORY OF SURGERY ...... 3 PRINCIPAL MECHANISMS OF SURGICAL DISEASE ...... 5 Congenital conditions ...... 5 APPROACHES TO SURGICAL PROBLEMS ...... 4 Acquired conditions ...... 6

A SHORT HISTORY OF SURGERY There can be no doubt that the fi rst surgeons were the The fi rst scientifi c departure from this barbaric treat- men and women who bound up the lacerations, contu- ment was taken by the great French military surgeon sions, fractures, impalements and eviscerations to which Ambroise Paré (1510–1590) who, while still a young man, man has been subject since he appeared on Earth. Since revolutionised the treatment of wounds by using only man is the most vicious of all creatures, many of these simple dressings, abandoning cautery and introducing injuries were infl icted by man upon man. Indeed, the ligatures to control haemorrhage. He established that his battlefi eld has always been a training ground for surgery. results were much better than could be achieved by the Right up to the 15th century, surgeons dealing with old methods. trauma were surprisingly effi cient. They knew their Ignorance of the basic sciences behind the practice limitations—they could splint fractures, reduce disloca- of surgery was slowly overcome. The publications of tions and bind up lacerations, but were only too aware The Fabric of the Human Body in 1543 by Andreas Ves- that open wounds of the skull, chest and abdomen were alius (1514–1564) and of The Motion of the Heart by lethal and were best left alone, as were wounds involving William Harvey (1578–1657) in 1628 were two notable major blood vessels or spinal injuries with paralysis. They landmarks. observed that wounds would usually discharge yellow Surgical progress however was still limited by two pus for a time; indeed this was regarded as a good prog- major obstacles. First, the agony of the knife: patients nostic sign and was labelled ‘laudable pus’. would only be prepared to undergo an operation to relieve The 15th century heralded a new and dreaded pathol- intolerable suffering (for example from a gangrenous ogy—the gunshot wound. These injuries would stink, limb, a bladder stone or a strangulated rupture) and, of swell and bubble with gas. There was profound systemic course, the surgeon needed to operate at lightning speed. toxicity and a high mortality. Of course, we now know Second, there was the inevitability of suppuration, with that this was the result of clostridial infection of wounds its prolonged disability and high mortality, which was with the extensive anaerobic tissue damage caused by often as high as 50% after amputation. Amazingly, both shot and shell. The surgeons of those times were shrewd these barriers were overcome within a couple of decades clinical observers but they surmised that these malign of each other. effects were due to gunpowder acting as a poison, for it In 1846, William Morton (1819–1868), a dentist was not until centuries later that the bacterial basis of working in Boston, Massachusetts, introduced the use of wound infection began to be understood. At that period ether as a general anaesthetic. This was followed a year the remedy was to destroy the poison with boiling oil or later by chloroform, employed by James Young Simpson cautery. Boiling oil was the more popular since it was (1811–1870) in Edinburgh, mainly in midwifery. These advocated by the Italian surgeon Giovanni da Vigo (1460– agents were taken up with immense enthusiasm across 1525), the author of the standard text of the day, Practica the world in a matter of weeks. In Arte Chirurgica Compendiosa. These treatments not only The work of the French chemist Louis Pasteur (1822– produced intense pain but also made matters worse by 1895) demonstrated the link between wound suppuration increasing the amount of tissue necrosis. and microbes. This led Joseph Lister (1827–1912), who 3

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was then a young professor of surgery in Edinburgh, to So at last, in the 1870s, the scene was set for the coming perform the fi rst operation under sterile conditions in enormous advances in every branch of surgery whose 1865. This was treatment of a compound fracture of the breadth and successes form the basis of this book. tibia in which crude carbolic acid was used as an antisep- tic. The development of antiseptic surgery and, later, Prof. Harold Ellis CBE MCh FRCS modern aseptic surgery progressed from there.

APPROACHES TO SURGICAL PROBLEMS What do surgeons do? cal trials, continue to broaden as equipment and skills become increasingly sophisticated. Surgeons are doctors who do operations, i.e. cutting tissue to treat disease, the patient usually being under some What sort of patients come to surgeons? form of anaesthesia. However, the range of work individ- ual surgeons undertake varies widely, depending on the Different types of surgeon practise in very different ways, culture in which they work and the resources avail- depending on their specialty and their level of responsi- able, the nature and breadth of their specialisation, what bility for emergency work. In the UK, most patients are other specialists are available, and the local needs. The referred to surgeons by another doctor, e.g. family practi- principles of surgery—access, dissection, haemostasis, tioner, accident and emergency (ER) offi cer or internal repair, reconstruction, preservation of vital structures and . The exceptions include patients suffering closure—are similar in all specialties. trauma who self-refer or are brought to a hospital by A general surgeon usually means one who principally ambulance. In some other countries, patients are able to undertakes general surgical emergency work and elective self-refer to the specialist they feel is most appropriate. abdominal gastrointestinal (GI) surgery. In geographi- Regardless of the route of referral, surgical patients fall cally isolated areas and regions where resources are scarce, into the following categories: such a surgeon might also undertake some gynaecology, ● Emergency/acute, i.e. symptoms lasting minutes to urology, paediatric surgery, orthopaedic and trauma hours or up to a day or two—often obviously surgery and perhaps basic ear, nose and throat (ENT) surgical conditions such as traumatic wounds, and ophthalmology, and even obstetrics. Conversely, fractures, abscesses, acute severe abdominal pain or in developed countries, there is an increasing trend gastrointestinal bleeding towards greater specialisation. Gastrointestinal surgery, ● Intermediate urgency—usually referrals from other for example, is often divided into ‘upper’ and ‘lower’ GI doctors based on suspicious symptoms and signs and surgery, and upper GI surgery itself may further divide sometimes investigations, e.g. suspected colonic into the subspecialties of hepatobiliary, laparoscopic, cancer, gallstones, renal or ureteric stones pancreatic and gastro-oesophageal cancer surgery. ● Chronic conditions likely to need surgery, e.g. Surgeons should not be thought of simply as ‘cutting varicose veins, hernias, arthritic joints, cardiac and sewing’ doctors. The perceived drama of surgery may ischaemia or rectal prolapse be superfi cially attractive but good surgery is rarely dramatic. Only when things go wrong does the drama The diagnostic process increase, and this is often not comfortable. Surgery is an art or craft as well as a science, and judgement, coping In order to manage surgical patients appropriately, a under pressure, taking decisive action when necessary, working diagnosis needs to be formulated to guide teaching and training skills and people management whether investigations are necessary and if so, their type skills are essential qualities. Operating skills can be learnt and urgency, and to determine what intervention (i.e. by most people, but the skills involved in deciding when treatment) is necessary. The process initially depends it is in the patient’s best interests to operate are absolutely upon whether immediate life-saving intervention is essential and must also be actively learnt and practised. required or, if not, the perceived urgency of the case. For Surgeons also play an important role in the diagnostic example, a patient bleeding from a stab wound might process, using both clinical skills and appropriate inves- need pressure applied to the wound immediately whilst tigations as part of their armamentarium. In this context, resuscitation and detailed assessment are carried out. At many surgeons undertake various forms of diagnostic the other end of the scale, if the symptoms suggest the and therapeutic endoscopy. These include gastroscopy, patient has a rectal carcinoma, a systematic and timely colonoscopy, urological endoscopy, thoracoscopy and approach is needed to obtain visual and histological con- arthroscopy. In addition, the indications for laparoscopic fi rmation of the diagnosis by endoscopy (colonoscopy 4 surgery, supported by the outcomes of good quality clini- plus biopsy) and radiological imaging (e.g. barium

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enema, CT scan). Tumour staging (see Ch. 13) endeav- monly present before a recognisable pattern has evolved ours to determine the extent of spread of a carcinoma in or else at an advanced stage when the typical clinical order to direct how radical treatment needs to be. Treat- picture has become obscured. The diagnostic process can ment may be curative (surgery, chemotherapy, radiother- also be confusing if all the symptoms and signs expected apy) or palliative if clearly beyond cure (stenting to for a particular diagnosis are not present, or if some of prevent obstruction, local tumour destruction using laser, the symptoms and signs seem inconsistent with the palliative radiotherapy). working diagnosis. This book seeks to develop a more logical and reliable Formulating a diagnosis approach to diagnostic method than simple pattern recognition by attempting to explain how the evolving The traditional approach to teaching surgical diagnosis is pathophysiology of the disease and its effect on the local for the student to attempt to correlate a patient’s symp- anatomy bring about the various clinical features. The toms and signs with recognised sets of symptoms and overall aim of this understanding is to target investiga- signs listed as characterising each disease. While most tions and interventions that give the best chance of cure diagnoses match their ‘classical’ descriptions at certain or symptom relief with the least harm to the patient. stages in their evolution, this may not be so when the patient initially presents for treatment. Patients com-

PRINCIPAL MECHANISMS OF SURGICAL DISEASE Surgical patients present with disorders resulting from sieve’. However, it should not become a substitute for inherited abnormalities, environmental factors or a com- logical thought based on the clinical fi ndings. bination of these in varying proportion. These are sum- marised in Box 1.1, providing a useful ‘fi rst principles’ CONGENITAL CONDITIONS framework or aide-mémoire upon which to construct a differential diagnosis. This is particularly useful when the The term congenital defi nes a condition that is present symptoms and signs do not immediately point to a diag- at birth, as a result of genetic and/or environmental nosis. This approach is often referred to as the ‘surgical infl uences in utero such as ischaemia or incomplete

Box 1.1 The surgical sieve

When considering the causes of a particular condition, it may be ● Other abnormalities of tissue growth—hyperplasia, helpful to run through the range of causes listed here. However, hypertrophy and cyst formation this should be only a fi rst step and not a substitute for thought. ● Iatrogenic disorders—damage or injury resulting from This approach gives no indication of the likely severity, frequency the action of a doctor or other health care worker; may be or importance of the cause. misadventure, negligence or, more commonly, system failure ● Drugs, toxins, diet and exercise Congenital —Prescription drugs—toxic effects of powerful drugs, ● Genetic maladministration, idiosyncratic reactions, drug ● Environmental infl uences in utero interactions. —Smoking—atherosclerosis, cancers, peptic ulcer Acquired —Alcohol abuse—personal violence, traffi c collisions ● Trauma—accidents in the home, at work or during leisure —Substance abuse—accidents, injection site problems activities, personal violence, road traffi c collisions —Atmospheric pollution—pulmonary problems ● Infl ammation—physical or immunological mechanisms —‘Western diet’—obesity, atherosclerosis, cancers ● Infection—viral, bacterial, fungal, protozoal, parasitic —Lack of exercise—obesity, osteoporosis, aches and ● Neoplasia—benign, premalignant or malignant pains ● Vascular—ischaemia, infarction, reperfusion syndrome, —Venomous snakes, spiders, scorpions and other creatures— aneurysms, venous insuffi ciency local and systemic toxicity ● Degenerative—osteoporosis, glaucoma, osteoarthritis, rectal ● Psychogenic—Munchausen syndrome leading to repeated prolapse operations, problems of indigent living, ingestion of foreign ● Metabolic disorders—gallstones, urinary tract stones bodies, self harm ● Endocrine disorders and therapy—thyroid function ● Disorders of function—diverticular disease, some swallowing abnormalities, Cushing’s syndrome, phaeochromocytoma disorders 5

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developmental processes such as malrotation of gut or disasters such as fl oods and earthquakes. Damage varies maternal ingestion of drugs such as thalidomide. Con- according to the nature of the causative agent, and the genital abnormalities of surgical interest range from visible surface injuries may give little indication of the minor cosmetic deformities such as right through to extent of deep tissue damage as, for example, in head potentially fatal conditions such as some congenital heart injuries or bullet wounds. defects, urethral valves and various gut atresias. Congenital abnormalities may become manifest at any Infl ammation time between conception and old age, although the Many surgical disorders result from infl ammatory pro- majority are evident at birth or appear in early childhood. cesses, most often stemming from infection. However, Some disorders are diagnosed antenatally, for example, infl ammation may also result from physical irritation, fetal gut atresias presenting during pregnancy with grossly particularly by noxious chemical agents, e.g. gastric acid/ excessive amniotic fl uid (polyhydramnios). There are pepsin in peptic ulcer disease or pancreatic enzymes in expanding specialist areas involving intrauterine surgical acute pancreatitis. interventions or fetal surgery, for example for urinary Infl ammation may also result from immunological tract obstruction or congenital diaphragmatic hernias. In processes which play a part in the infl ammatory the neonatal period, abnormalities such as urethral valves bowel disorders of ulcerative colitis and Crohn’s disease. (which may present with obstructive renal failure) may Whether they constitute cause or effect is not yet known. become evident. During infancy, conditions such as con- Autoimmunity, in which an immune response is directed genital hypertrophic pyloric stenosis come to light. In at one or more of the body’s own constituents, is recog- childhood, incompletely descended testis may become nised in a growing number of surgical diseases such as evident, although this may be suspected much earlier. Hashimoto’s thyroiditis and rheumatoid disease. Finally, some congenital disorders may present at any stage from birth to early adulthood. For example, a patent pro- Infection cessus vaginalis may be the precursor to an inguinal Primary infections commonly presenting to surgeons hernia even into late middle age. include soft tissue infections such as abscesses and cellu- Whilst many congenital abnormalities give rise to litis, primary joint infections and tonsillitis. Typhoid disease by direct anatomical effects, other abnormalities may cause caecal perforation and abdominal produce disease by more subtle disruption of function, may be discovered at laparotomy. Amoebiasis may cause with the underlying disorder only revealed on appropri- ulcerative colitis-like effects. Preventing and treating ate investigation. For example, ureteric abnormalities infection is also an important factor in many surgical which allow urinary refl ux from the bladder predispose emergencies such as acute appendicitis or bowel perfora- to recurrent kidney infections. tion. Despite the rational use of prophylactic and thera- peutic antibiotics, postoperative infection remains a ACQUIRED CONDITIONS common complication of surgery. Acquired surgical disorders result from direct or indirect Neoplasia damage infl icted by trauma or disease or from the body’s response to these, or else present as an effect or side effect Certain benign tumours such as lipomas are very of treatment. For example, obstruction of the bladder common and are excised mainly for cosmetic reasons. outlet may result from benign prostatic hypertrophy, Less commonly, benign tumours cause mechanical prob- from the fi brotic response to gonococcal urethritis or lems such as obstruction of a hollow viscus or surface from damage infl icted during urethral instrumentation. blood loss, e.g. gastric leiomyoma. Benign endocrine The classifi cation detailed here provides a framework to tumours may have to be removed because of excess help consider the causes of surgical disease, but it should hormone secretion (see Endocrine disorders later). Finally, be remembered that particular conditions may fi t under benign tumours may be clinically indistinguishable from more than one heading, and that the mechanism behind malignant tumours and are removed or biopsied to obtain some surgical disorders is still poorly understood. a histological diagnosis. Malignant tumours may present with signs and symp- Trauma toms resulting from the primary tumour, the effects of Tissue trauma, literally injury, includes in its wider sense metastases (‘secondaries’) and in some cases, systemic damage infl icted by any physical means, i.e. mechanical, effects such as cachexia. Malignant tumours are respon- thermal, chemical or electrical mechanisms or ionising sible for a large part of the general surgical workload. radiation. Common usage, however, tends to imply Vascular disorders mechanical injury, either blunt or penetrating, as caused by accidents in industry or in the home, road traffi c col- A tissue or organ becomes ischaemic when its arterial 6 lisions, fi ghts, fi rearm and other missile injuries or natural blood supply is impaired; infarction occurs when cell

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life can no longer be sustained. Atherosclerosis leads to Endocrine disorders and hormonal therapy progressive narrowing of arteries which often results in Hypersecretion of certain hormones, as in thyrotoxicosis chronic ischaemia causing symptoms such as angina and hyperparathyroidism, may require surgical removal pectoris or intermittent claudication. It also predisposes or reduction of glandular tissue. Endocrine tumours, to acute-on-chronic ischaemia when diseased vessels both benign and malignant, may present with metabolic fi nally occlude. Other common causes of acute arterial abnormalities such as hypercalcaemia caused by a para- insuffi ciency are thrombosis, embolism and trauma thyroid adenoma, Cushing’s syndrome resulting from an involving blood vessels. Arterial embolism is a cause of adrenal adenoma or episodic hypertension caused by a acute ischaemia of limbs, intestine or brain; these emboli phaeochromocytoma. often originate in the heart. If the blood supply is restored Diabetes mellitus, particularly when poorly con- after a period of ischaemia, for example by embolectomy, trolled, may result in a range of complications of surgical further damage can ensue as a result of reperfusion importance, for example retinopathy and cataract forma- syndrome. tion, as well as predisposing to atherosclerosis. When a portion of bowel becomes strangulated, the Hormone replacement therapy in postmenopausal initial mechanism of tissue damage is venous obstruction women brings mixed benefi ts: it slows osteoporosis and and this fairly rapidly progresses to arterial ischaemia reduces the risk of colorectal cancer whilst slightly increas- and infarction. ing the risks of breast and endometrial cancer. There is An aneurysm is an abnormal dilatation of an artery also some evidence of an increased rate of thromboem- resulting from degeneration of connective tissue. This bolism, as there is with higher oestrogen-containing oral may rupture, thrombose or generate emboli. contraceptive pills. Chronic venous insuffi ciency in the lower limb causing local venous hypertension is responsible for the majority of chronic leg ulcers. Other abnormalities of tissue growth Growth disturbances such as hyperplasia (increase in the Degenerative disorders number of cells) and hypertrophy (increase in the size of cells) may give rise to surgical problems, in particular This is an inhomogeneous group of conditions character- benign prostatic hyperplasia, fi broadenosis of the breast ised by deterioration in one or more of the body tissues and thyroid enlargement (goitre). as life progresses. In the musculoskeletal system, osteo- In surgery, the term cyst is imprecisely used to describe porosis decreases the density of bone and impairs its a mass which appears to contain fl uid because of its structural integrity, making fragility fractures more likely characteristic fl uctuance and transilluminability. A cyst is such as crush fractures of vertebrae or fractures of the defi ned as a closed sac with a distinct liming membrane femoral neck. Spinal disc and facet joint degeneration is that develops abnormally in the body. A variety of differ- common, causing back pain and disability, and osteoar- ent pathological processes produce cysts (see p. ••). Most thritis is widely prevalent, particularly in later life. The are benign but some may be associated with malignant almost universal musculoskeletal aches and pains of change in the wall. later life are probably caused by degeneration of muscle, tendon, joint and bone. Iatrogenic disorders Other degenerative disorders include age-related retinal macular degeneration, glaucoma, the inherited Iatrogenic damage or injury is that resulting from the disorder retinitis pigmentosa, and certain neurological action of a doctor or other health care worker. It may be disorders (Alzheimer’s, Huntington’s and Parkinson’s an unfortunate outcome of an adequately performed disease, bulbar palsy). Atherosclerosis and aneurysmal investigation or operation, e.g. perforated colon during arterial diseases are often non-specifi cally labelled colonoscopy or pneumothorax as a result of attempted degenerative but their pathogenesis is gradually being aspiration of a breast cyst. This type of injury could be elucidated. termed surgical misadventure. However, if the damage results from a patently wrong procedure, e.g. amputation of the wrong leg or removal of the wrong kidney, then Metabolic disorders negligence is likely to be proven. Such wrong site surgery Metabolic disorders may be responsible for stones in the is easily avoided by preoperative site marking. Other gall bladder (e.g. haemolytic diseases causing pigment potentially negligent actions include retained surgical stones) or in the urinary tract (e.g. hypercalciuria and swabs after laparotomy or arterial trauma during central hyperuricaemia causing calcium and uric acid stones venous line insertion. Complications of bowel surgery respectively). Hypercholesterolaemia is a major factor in such as anastomotic leakage may result from poorly per- atherosclerosis and hypertriglyceridaemia is a rare but formed surgery but can occur in expert hands; only care- important cause of acute pancreatitis. fully audited results can demonstrate whether the surgeon 7

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is profi cient. Wrong drugs or doses are usually iatrogenic Environmental pollution almost certainly affects health: and are covered under the next heading. for example, micro-fi ne particles produced by diesel It is unusual for iatrogenic problems to be simply engines cause pulmonary infl ammation. due to one person’s failure. More often it is a system Alcohol and substance abuse may have a surgical failure, with inadequate checks and balances in the dimension: alcohol may lead to personal violence or road system. traffi c collisions as a result of intoxication; cannabis smoke is carcinogenic and causes dysplasias and prema- lignant lesions of the oral mucosa as well as contributing Drugs, toxins and diet to mental health problems of acute anxiety and psychotic- Problems with prescribed drugs include unavoidable like paranoid thoughts. Misdirected injection of opioids toxic effects of certain chemotherapeutic agents, e.g. neu- and other drugs may cause abscesses, false aneurysms tropenia, and the side effects of drugs such as non- and even arterial occlusion. steroidal anti-infl ammatory drugs (NSAIDs) causing The so-called ‘Western diet’ rich in fat and calories and duodenal perforation, or codeine phosphate causing con- low in vegetables, fruit and fi bre is associated with a range stipation. Drug allergy, idiosyncrasy or anaphylaxis of diseases including colorectal and breast cancers, may result from individual responses to almost any drug, obesity, dyslipidaemias, diabetes and hypertension. This and interactions between drugs may cause adverse effects. is particularly so when combined with a sedentary life. In this respect warfarin is a prime culprit. Maladministra- Dietary fi bre protects against colorectal adenomas and tion of drugs may also cause problems with, for example, carcinomas as well as diverticular disease. the wrong drug being given for intrathecal chemotherapy causing paralysis. In many countries, venomous creatures Psychogenic disorders such as spiders, snakes or scorpions cause toxic and some- Psychogenic disorders are not often a source of surgical times fatal harm. disease but Munchausen syndrome patients may present Cigarette smoking is the biggest single preventable with abdominal pain and become subjects of repeated cause of death and disability in developed countries. laparotomies, psychiatric patients living rough may suffer Cigarette smoke is highly addictive and contains an array with exposure and frostbite, and others may repeatedly of carcinogens in the tar, vasoconstrictors in the form of cause self harm or swallow foreign bodies, even such nicotine, and carbon monoxide that preferentially binds items as razor blades or safety pins. to haemoglobin. Not surprisingly, it is a powerful factor in a huge range of diseases including cardiovascular dis- Disorders of function orders affecting the heart, limbs and brain, dysplasias and cancers of the lung, mouth and larynx, respiratory A range of common disorders are defi ned by the abnor- disorders such as pneumonias, chronic obstructive pul- malities of function they cause, although in most cases monary disease (COPD) and emphysema via small their pathogenesis remains ill understood. The gastroin- airways infl ammation, stillbirth and peptic ulcer disease. testinal tract is particularly susceptible, with conditions Smoking compounds the atherogenic effects of diabetes such as idiopathic constipation, irritable bowel syndrome and is also strongly associated with premature skin ageing. and diverticular disease.

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