Surgery can be broadly classified into three groups according to the time scale involved. First, there is the routine operation, for which there is no desperate urgency, for example a hernia repair; second is the urgent operation, such as a cancer operation, involving a condition which needs to be dealt with quickly; third is the emergency operation, where a delay of only minutes can result in either a great deal of pain or even death.
Who needs surgery?
The short answer to this question is any patient who has a condition which is causing, or will cause, significant disability or pain, and which cannot be treated
Medically (which usually means by drugs) or by any other form of therapy. But, just as with other therapies, operations are not risk-free. The surgeon must always balance the risks of surgery against the possible benefits before making a decision.
For example, if a patient has had the same problem for a number of years before first mentioning it to his doctor, and providing there is minimal prospect of complications, then there is no degree of urgency for surgery. The conditions that often end up on waiting lists are hernia repairs, varicose vein removal, hae-morrhoidectomies (piles removal), gall bladder removal, hip replacements and removal of tonsils and adenoids. In a busy hospital this list is often much longer.
Who qualifies for emergency surgery? Such patients are sometimes referred by family doctors, and they may also be patients admitted to a hospital casualty department; if a doctor thinks an individual is in need of immediate treatment then a surgeon sees the patient straight away.
This may be for a condition that is quite trivial in terms of threatening life but which is extremely painful, such as a large abscess, or for an immediately life-threatening problem such as severe internal bleeding following an accident.
Admission for surgery
When a patient is brought into hospital he or she is formally ‘admitted’. This involves in general taking a careful medical history (if there is enough time for it), not only about the patient’s present condition but also with regard to his or her general state of health and past medical history, use of medicines, and the presence of allergies, which may often be very relevant. The patient is then carefully examined, not only to look at the current disorder but also to check for other disorders, and to make sure that he or she is fit enough to withstand a general anaesthetic if this is considered necessary. A number of tests may then be performed.
Surgery is an ‘insult’ to the body and the surgeon must ensure that the patient is as fit as possible under the circumstances. Sometimes adults about to have a general anaesthetic undergo a chest X-ray to double-check the state of the heart and lungs. Generally men and women over the age of 40 will also have an electrocardiogram (ECG) to check the condition of the heart’s functioning. Depending on the site of the injury or disorder further X-rays may be taken, such as X-rays of the abdomen for general abdominal pain or X-rays of a limb for suspected fractures. Blood tests are also performed prior to surgery, both as an aid to diagnosis and also as a further check prior to anaesthesia. The doctor makes sure the patient is not anaemic, or so ill that body chemicals have been disturbed, in which case these conditions may need treatment before surgery is attempted. In addition, a routine urine sample is analyzed for the presence of blood or sugar; some cases of previously unsuspected diabetes are picked up in this manner.
Preparing for an operation
Once the patient has been accepted for surgery there follows a number of routine preparations. If it is a planned operation on the large intestine for instance, then this needs to be cleared out, to ensure a clean operating area so as to lessen the chance of infection. This is generally achieved by giving the patient a laxative, which encourages the intestine to empty naturally, although rapidly. Depending on the site of
The operation, the patient’s skin may need shaving. Once under a general anaesthetic, people lose some of their basic reflexes. One of these is the ability to get rid of vomit, which may therefore be inhaled. For this reason, in all but cases of extreme emergency, anyone about to undergo a general anaesthetic is starved for between four to six hours to ensure that the stomach is completely empty. ‘Pre-medication’ is almost always given before a general anaesthetic. It usually consists of a drug to relax the patient, which has the effect of reducing secretions from the airways and gut. Whether or not an antibiotic is given depends on the type of surgery that is planned. These are given oh the ward, so that the patient is as relaxed as possible before being transferred to the operating theatre.
Once in the anaesthetic room of an operating theatre, the patient is checked by a nurse and the anaesthetist. When they are happy that everything is satisfactory, they start administering the anaesthetic. For general anaesthesia this usually begins by asking the patient to breathe in oxygen. While he or she is doing this a drug is given intravenously which rapidly induces sleep. This is called induction.
Different types of anaesthetic are then used to maintain unconsciousness. The patient may need to have a tube put through the mouth into the windpipe so that breathing can be maintained. This is especially important when paralyzing drugs are used because such drugs affect the breathing muscles so that the patient is put on a ventilator for the operation. (Paralyzing drugs are needed to relax the muscles of the body which might otherwise contract, making surgery extremely difficult.) When the anaesthetist is happy with the patient’s condition, he or she is transferred into the operating room.
Of course, not all operations are performed under general anaesthetic. Small operations, and occasionally larger ones when a person is not fit enough to withstand a general anaesthetic, are often carried out under local anaesthesia. The patient is not asleep, but the area to be operated on is made completely numb. This can be done either by direct injection of the area with local anaesthetic or by injecting anaesthetic around the nerves supplying this area; the latter is called a ‘nerve block’. If the anaesthetic is injected in the space around the spinal cord, large areas of the lower body can be made numb. This method is often used to perform a Caesarian section, for instance. A local anaesthetic can be given either before the patient is transferred to the theatre, or in the theatre itself.
The operating conditions
Operations in hospitals are performed under highly sterile conditions. This means that as far as possible all micro-organisms are killed or excluded. This is achieved, firstly, by the meticulous cleaning of the theatre every day, morning and night and after any case thought to be ‘dirty’. In addition, all theatre staff change into specially cleaned clothes, often called theatre gear, so that any contamination from the outside is lessened. They wear masks and hats to prevent transmission of germs in airborne mucus or saliva droplets, or by skin micro-fragments. The surgeon, his assistants and the nurses responsible for looking after the instruments ‘scrub up’ with an antiseptic solution to sterilize their hands and arms. Finally they put on sterile gowns and gloves which provide a further barrier to germs. The operation does not start until everyone is ready: not only the surgeon, but also the scrub nurse, and, very importantly, the anaesthetist. For a long and complex operation a surgeon may have a vast array of scalpels, forceps, clamps, retractors and other instruments, plus endless swabs, suction tubes and other cleaning equipment. Most surgical instruments are sterilized using an autoclave sterilizer, which kills bacteria by heat and steam; some special instruments are sterilized using either chemicals or radiation. The length of an operation may vary from a few minutes for a very simple procedure to 20 hours or more for an extremely complicated case such as the reconstruction of face and head tissues of a child born with severe congenital defects. This sort of lengthy procedure involves more than one specialized team.
The basics of an operation
Most operations need a cut, or incision, to access the operation site. This is made with a scalpel, cutting through the skin and subcutaneous fat. Depending on the position there may be further layers of fat, muscle and other tissues that need to be divided or incised.
Because of the thousands of microscopic blood vessels that are cut there is always bleeding to begin with, but most of it stops spontaneously as the vessels retract and the blood clots. Larger vessels such as small arteries and veins tend to continue bleeding and are, therefore, usually ligated (tied off), or cauterized, as the surgeon proceeds.
Once the operation has been performed the tissue layers have to be closed in turn. The final wound and its sutures (stitches) are usually the – technically – least important part, but it is the only part that the patient sees afterwards.
There are many kinds of materials used for suturing and ligation, depending on the site. Basically they can be absorbable or non-absorbable (degradable or non-degradable). Either of these may be made up of natural or man-made materials. For example, ‘catgut’ is made from sheep’s intestine, and used in bowel surgery for joining (anastomosing) various parts, and for other sites where the surgeon wants rapid healing without the sutures having to be removed. Such absorbable sutures gradually break down and are removed by the body’s natural defences. The sort of sutures that most people see in the skin are black silk or nylon. These need to be removed at a later date.