Surgery

An operation is conducted in aseptic conditions. All instruments are sterilized and the surgical team wear sterile clothes.

Surgery is one of the fields of medicine in which great advances are continually being made stimulated as often by misfortunes, such as accidents and war, as by advances in other areas of medicine and science. New techniques and equipment enable surgeons to undertake remarkable treatments, from transplanting organs, such as the heart or kidney, to replacing a severed limb and restoring its function.

Diagnosis has also been considerably improved, both by refinements in slightly older techniques such as the electroencephalograph (EEG) and the electrocardiograph (EKG) and by the invention of new ones such as the use of ultrasound, or of a computer to interpret X rays in the process known as computerized axial tomography (CAT) scanning.

Surgery itself has undergone remarkable refinement, with the result that many seriously ill or injured people can now be successfully treated, whereas perhaps only ten years ago little or nothing could have been done for them.

New surgical techniques

A cardiopulmonary bypass, commonly known as a heart-lung machine, makes it possible for a surgeon to maintain the blood circulation while a patients heart is stopped. Venous blood from the patient’s heart is oxygenated, displaced carbon dioxide and excess oxygen are removed, and the filtered blood is pumped back into the patient’s circulation via an artery in the leg.

Among the most important new instruments and techniques available to the surgeon are endoscopy, microsurgery, cryosurgery, laser surgery, and patient monitoring devices.
An endoscope is a device for looking inside a patient’s body. Most modern endoscopes employ fiber optics, in which strands of fiber packed together in a long, thin, flexible tube carry light (or an image) from one end of the tube to the other. The tube thus becomes an excellent diagnostic aid if inserted through a bodily orifice (or small surgical incision) to the site of whatever the physician wants to examine. It can also be used as a surgical instrument when the internal end of the tube is fitted with a wire loop or blades, which can cut or cauterize tissue. Stones in the bladder, for instance, can be easily crushed and washed out using this method (litholapaxy), with no need for abdominal surgery. In parts of the body that are particularly difficult to reach, a computer-enhanced image intensifier and a visual display unit (VDU, a television screen) may be used in conjunction with the endoscope so that its pictures are made quite clear.

A VDU attached to a microscope is now commonly used for microsurgery, which deals with the smallest and most sensitive parts of the body, such as individual nerve endings and blood vessels. Using microsurgery, it is possible not only to reattach an accidentally amputated limb, but to reconnect many of the neural pathways and thus enable the patient eventually to regain movement and even some feeling in the limb. This is an exceptional use, however; more common areas for microsurgery are the larynx and the ear.

Open-heart surgery, shown below, has become a common technique since the development of the heart-lung machine, which takes over the functions of the patient’s heart and lungs so that the operation can be performed with the heart stopped.

Another modern technique is that of using localized but extreme cold (below —4° F„ — 20° C) to freeze and thus destroy tissue. This method called cryosurgery is not in common use, but is nevertheless occasionally employed in brain surgery, in ophthalmology, and in treating some skin disorders.

Probably the field in which most advances have been made recently uses lasers, which have various surgical applications. Pulsed laser beams can be produced either as an extremely narrow, concentrated ray with a diameter of only a fraction of a millimeter (used as a scalpel), or as a wider, diffuse ray (used to “vaporize” tissue over an area). The laser’s main ad vantages are that it is totally aseptic and that particularly when it is used as a scalpel the heat produced cauterizes smaller blood vessels instantly, so that blood loss (and therefore shock) is greatly reduced. Moreover, a laser beam can be used in combination with an endoscope. The overall power of a beam depends on the type of laser. Carbon-dioxide lasers are extremely powerful (and are used mainly for the vaporization of unhealthy tissue). But they need a marker beam from a second laser (usually an argon or neon type) projected along the same path, because they are otherwise invisible. Probably the most common application for lasers in medical practice is to remove unhealthy tissue in a condition known as precancer of the cervix. The best-known use, however, is in “welding” back a detached part of the retina of the eye.

Coronary artery disease can be treated surgically by rerouting the blood through a by-pass. In this operation, a section of saphenous vein from the patient’s leg is used as the replacement blood vessel.

New and improved drugs for use as anesthetics during operations are constantly being discovered. At the same time, refinements are also being made in the equipment used for monitoring the patient’s condition during an operation also the responsibility of the anesthetist. Most operating theaters now have an array of automatic electronic monitoring devices.

A kidney transplant is one of the most successful types of transplant operations. The new kidney, from a donor, is positioned at the top of the pelvic girdle and turned upside down to facilitate connections with the renal blood supply and the ureter. The adrenal glands are left in their original positions.

Modern surgery

Nearly all parts of the body can be treated surgically; some organs and body systems, however, present the surgeon with special problems. Until quite recently, most operations were performed by general surgeons. Even today, although specialization is increasingly important, a general surgeon is the most likely person to deal with appendectomies, gallbladder operations, breast operations, and surgery on the gastrointestinal tract. In some cases, the general surgeon may also be concerned with the removal of benign or malignant growths. In this context, a surgeon may have to decide, during the operation, how much tissue to remove to prevent further spread of cancerous growth.

During cornea transplants, surgeons replace a patient’s damaged cornea with a healthy one, usually taken from a deceased donor. Because the cornea has no direct blood supply, cornea transplants do not entail the careful tissue matches that other transplants require.

Specialist surgeons are concerned not only with the appropriate surgical techniques but also with all other aspects of medical care relating to their speciality.

A neurosurgeon, for example, is concerned with operations on the nervous system: the brain, spinal cord, spine, and nerves. Injuries to the brain through accidents are all too frequent; tumors of the brain and spinal cord, and congenital disorders, such as hydrocephalus, are other common problems. Technical advances that have been of particular benefit to neurosurgeons include cryosurgery and laser surgery, both of which may be used in highly specific operations on the brain.

An orthopedic surgeon deals with disorders of the bones and joints. Common operations include the correction of congenital defects, such as clubfoot or scoliosis (curvature of the spine), and the insertion of metal or plastic artificial joints, for example, in the hip. Treatment of fractures is important too, and usually involves returning broken bones to their correct position and fixing them there-using splints or traction until they have healed. Other orthopedic operations include the treatment of people with herniated disks, accident victims, and patients with bone cancer.

Urological surgeons deal with disorders affecting the urinary tract and male reproductive organs. Common problems include prostate disorders, kidney stones and kidney disease, and cancer of the kidneys, bladder, prostate, or testicles.

Obstetricians and gynecologists are concerned with pregnancy, childbirth, and female reproductive problems. Careful monitoring and prenatal care minimize obstetric difficulties. Common gynecological operations include D and C (dilatation of the cervix and cur-rettage of the uterus) for diagnostic or screening purposes, or for the removal of small growths (polyps) in the uterus; the removal of fibroids; removal of the uterus (hysterectomy); and surgery to treat cancer of the uterus or cervix.

The cardiac (heart) surgeon has derived particular benefit from technological advances, especially in the development of the heart-lung machine, which takes over the functions of the heart and lungs of a patient undergoing surgery so that the heart can be operated on while stopped; in the use of computers to aid monitoring; and in techniques that involve cooling the patient to slow down metabolism during an operation.

Transplant surgery involves the replacement of a diseased or failed organ (such as kidneys or the heart) with a healthy one, usually taken from a donor who has just died. By the early 1980’s, heart transplants were still comparatively rare, although there had been some remarkable successes. Kidneys and bone marrow can, however, be transplanted from a living donor. The chief difficulty in transplant surgery is ensuring that the new tissue is not rejected by the recipient, whose natural immune response to foreign tissue can be as acute as it is to agents that cause allergy or disease. This difficulty can be largely overcome by careful matching of the tissue types of donor and patient, and by using special drugs that suppress the patient’s immune response. (The use of these drugs is itself dangerous, however, in that the patient is thus left without any natural defenses against infection.)

Replacement (or “spare part”) surgery avoids the problem of rejection by using inert plastic or metal devices to replace or strengthen natural ones. Some arteries, veins, heart valves, and joints can be replaced with artificial equivalents. Replacement of limbs or parts of limbs has been possible for a long time, but the sophistication of artificial limbs has reached such a degree nowadays that it is possible to use the nervous impulses in the remaining portion of the damaged limb to control the battery-operated replacement (prosthesis).

A plastic surgeon is concerned with the reconstruction and cosmetic repair of damaged surface tissue and bone, whether for aesthetic or psychological reasons, or after damage caused by burns or other injury.

An ophthalmic surgeon deals with the eyes, especially with the removal of cataracts (opaque patches in the lens), replacement of a damaged or diseased cornea by a corneal graft, or with the repair of a damaged or detached retina. Microsurgical techniques and advances, such as the medical use of lasers, particularly benefit ophthalmic surgery. They are also important for operations on the minute and delicate organs of the ear.

Removal of the tonsils and adenoids is a common ear, nose, and throat (ENT) operation, as is surgery to treat certain inner ear infections. Specialists in ENT surgery also remove tumors in the sinuses, mouth, larynx, and throat.

Common major operations

Most major operations are abdominal, and the most common of these include appendectomy (removal of the appendix); removal of ulcerated parts of the digestive tract, all or part of diseased organs, and benign or malignant growths; and the repair of hernias.

Accidents particularly road accidents are another common reason for major surgery. Further types of major surgery include urinary tract, cardiovascular, thoracic, and neurosurgical operations.

Orthopedic surgery includes the replacement of damaged or diseased joints. This X ray shows an “artificial hip,” which comprises a metal pin fixed in the neck and body of the femur and a ball-and-socket joint that replaces the hip joint itself. The ball joint fits into the socket as the head of a normal femur fits into the acetabulum.

Preparations for surgery

Before an operation, the patient is tested for any condition that might complicate the operation, such as high blood pressure. Solid food is restricted for a period before any operation that requires a general anesthetic, in case the patient vomits while anesthetized. Finally, premedication is given to relax the patient before the anesthetic itself is administered. Preoperative antibiotics may also be given to minimize the risk of internal infection, particularly if surgery is to be carried out on or near the gastrointestinal tract.

Meanwhile, sterile conditions are established in the operating theater, and sterile instruments and clothing are obtained. Members of the surgical team “scrub up” by washing their hands extremely thoroughly and wear sterile clothing, which includes gloves, face masks, hats, and overgarments.
The patient is anesthetized before entering the operating theater, usually by an intravenous injection of barbiturate. Anesthesia is usually maintained during the operation by means of inhaled gas and monitored throughout the operation by an anesthetist or anesthesiologist.

Operations are performed by a skilled and specialized team consisting of the surgeon (or surgeons), various assistants, an anesthetist or anesthesiologist, and, where special apparatus is being used, a technician to operate it. A surgeon may also require the presence of one or more specialists, from radiologists to pathologists.

Postoperative care is very important. After surgery, the patient is taken to a recovery room until the effects of the anesthesia wear off and he or she regains consciousness. If recovery is satisfactory, the patient is returned to the ward. If there are postoperative complications, however, the patient may need to be kept temporarily in an intensive care unit.