THE MERCK MANUAL MEDICAL LIBRARY: The Merck Manual of Medical Information--Home Edition
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Surgery

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Surgery is the term traditionally used for treatments that involve cutting or stitching tissue. However, advances in surgical techniques have made the definition more complicated. Sometimes lasers, rather than scalpels, are used to cut tissue, and wounds may be closed without stitches. In modern medical care, distinguishing between a surgical and medical procedure is not always easy; however, making that distinction is not important as long as the doctor performing the procedure is well trained and experienced.

Surgery is a broad area of care and involves many different techniques. In some surgical procedures, tissue is removed. In others, blockages are opened. In still others, arteries and veins are attached in new places to provide additional blood flow to areas that do not receive enough. Grafts, sometimes made of artificial materials, may be implanted to replace blood vessels or connective tissue, and metal rods may be inserted into bone to replace broken parts.

A diagnosis is sometimes accomplished by doing surgery. A biopsy, in which a piece of tissue is removed for examination under a microscope, is the most common type of diagnostic surgery. In some emergencies, in which there is no time for diagnostic tests, surgery is used for both diagnosis and treatment. For example, surgery may be needed to quickly identify and repair organs that are bleeding from a gunshot wound.

The urgency of surgery is often described by three categories—emergency, urgent, and elective. Emergency surgery, such as stopping rapid internal bleeding, is performed as soon as possible because minutes can make a difference. Urgent surgery, such as removal of an inflamed appendix, is best performed within hours. Elective surgery, such as replacement of a knee joint, can be delayed for some period of time, until everything has been done to optimize a person's chances of doing well during and after the surgical procedure.

Cosmetic Surgery

Cosmetic surgery involves a wide variety of operations, including removing facial and neck wrinkles (rhytidectomy); removing fat and wrinkles from the abdomen (abdominoplasty); enlarging or reducing breasts (mammoplasty); restoring scalp hair (hair replacement surgery); altering the appearance of facial features, such as the jaw (mandibuloplasty), eyelids (blepharoplasty), and nose (rhinoplasty); removing body fat (liposuction); and eliminating varicose veins (sclerotherapy).

Popular and tempting as cosmetic surgery may be, there are certain drawbacks and precautions:

  • It is expensive.
  • It poses risks, including serious health risks as well as the possibility that appearance may be less pleasing to the person than it was originally.
  • Because obtaining the best results requires close adherence to instructions after the operation, cosmetic surgery is recommended only for highly motivated people.
  • A person should choose a doctor who has met a medical specialty's standards for practice (board certification) and who has extensive experience performing the procedure.

Anesthesia

Because surgery is generally painful, it is almost always preceded by the administration of some type of anesthesia. Anesthesia blocks the perception of pain. Anesthesia may be local, regional, or general. Anesthesia is typically given by health care practitioners specially trained and certified in providing anesthesia. These practitioners may be doctors (anesthesiologists) or nurse practitioners (nurse anesthetists). Nurse anesthetists practice under the direction of an anesthesiologist.

Local and Regional Anesthesia: These types of anesthesia consist of injections of drugs (such as lidocaine or bupivacaine) that numb only specific parts of the body. In local anesthesia, the drug is injected under the skin of the site to be cut, numbing only that site. In regional anesthesia, which numbs a larger area of the body, the drug is injected around one or more nerves and numbs an area of the body supplied by those nerves. For example, injecting a drug around certain nerves can numb fingers, toes, or large parts of limbs. One type of regional anesthesia involves injecting a drug into a vein (intravenous regional anesthesia). A device such as a woven elastic bandage or blood pressure cuff compresses the area where the limb joins the body, trapping the drug within the veins of that limb. Intravenous regional anesthesia can numb an entire limb.

During local and regional anesthesia, the person remains awake. However, doctors sometimes give antianxiety drugs intravenously to calm and relax the person. Rarely, numbness, tingling, or pain can persist in the numbed area for days or even weeks after the surgical procedure.

Spinal and epidural anesthesia are specific types of regional anesthesia in which a drug is injected around the spinal cord in the lower back. Depending on the site of the injection and position of the body, a large area (such as from the waist to the toes) can be numbed. Spinal and epidural anesthesia are useful for operations of the lower body, such as hernia repairs and prostate, rectal, bladder, leg, and some gynecologic operations. Spinal and epidural anesthesia also can be useful for childbirth. Headaches occasionally develop in the days after spinal anesthesia but usually can be treated effectively.

General Anesthesia: In general anesthesia, a drug that circulates throughout the bloodstream is given, rendering the person unconscious. The drug can be given intravenously or inhaled. Because a general anesthetic slows breathing, the anesthesiologist inserts a breathing tube in the windpipe and a ventilator breathes for the person if the operation is long. For short operations, however, such a tube may not be necessary. Instead, the anesthesiologist can support breathing by using a hand-held breathing mask. General anesthetics affect vital organs, so the anesthesiologist closely monitors the heart rate, heart rhythm, breathing, body temperature, and blood pressure until the drugs wear off. Fortunately, serious side effects are very rare.

Did You Know...

  • Improved technologies and procedures have made serious side effects of general anesthesia vary rare.

Major and Minor Surgery

A distinction is sometimes made between major and minor surgery, although many surgical procedures have characteristics of both.

Major Surgery: Major surgery often involves opening one of the major body cavities—the abdomen (laparotomy), the chest (thoracotomy), or the skull (craniotomy)—and can stress vital organs. The surgery usually is performed using general anesthesia in a hospital operating room by a team of doctors. A stay of at least one night in the hospital usually is needed after major surgery.

Minor Surgery: In minor surgery, major body cavities are not opened. Minor surgery can involve the use of local, regional, or general anesthesia and may be performed in an emergency department, an ambulatory surgical center, or a doctor's office. Vital organs usually are not stressed, and surgery can be performed by a single doctor, who may or may not be a surgeon. Usually, the person can return home on the same day that minor surgery is performed.

Surgical Risk

The risks of surgery (that is, how likely surgery is to cause death or a serious problem) depend on the type of surgery and characteristics of the person.

Types of surgery that have the highest risk include

  • Heart or lung surgery
  • Prostate gland removal
  • Major operations on the bones and joints (for example, hip replacement)

Generally, the poorer the person's overall health, the higher the risks of surgery. Some particular health problems that increase surgical risk include

  • Severe chest pain (angina)
  • Recent heart attack
  • Severe heart failure
  • Undernutrition (common among institutionalized elderly people)
  • Severe disorders of the lungs or liver
  • Chronic kidney disease
  • Chronic lung disease (often smoking-related)
  • Weakened immune system (for example, because of long-term corticosteroid treatment)
  • Diabetes (especially if poorly controlled)

Risks are often higher among elderly people (see Surgery: Spotlight on AgingSidebar); however, risks are determined more by general health than by age. Chronic disorders that increase surgical risk and other treatable disorders, such as dehydration, infections, and imbalances in body fluids and blood chemistries, should be controlled with treatment as well as possible before an operation.

Second Opinion

The choice to undergo surgery is not always clear. There may be nonsurgical options for treatment, and there may be several options for the kind of surgical procedure. Thus, a person may seek the opinion of more than one doctor. Some health insurance plans require a second opinion for elective surgery. However, experts may disagree on which doctor should give the second opinion.

  • Some experts advise obtaining a second opinion from a doctor who is not a surgeon to eliminate any bias toward surgery when nonsurgical treatment is an option.
  • Others advise that another surgeon give the second opinion, believing that a surgeon knows more about the advantages and disadvantages of surgery than would a nonsurgeon.
  • Some experts recommend establishing up front that any surgeon giving a second opinion will not perform the surgical procedure, so that there is no conflict of interest.

Surgery Through a Keyhole

Technical advances now make it possible to perform surgery with smaller incisions and less tissue disruption than occurs with traditional surgery. To perform this surgery, surgeons insert tiny lights, video cameras, and surgical instruments through keyhole-sized incisions. The surgeons can then perform procedures using the images transmitted to video monitors as guides for manipulating the surgical instruments. This kind of surgery is called laparoscopic surgery when performed in the abdomen, arthroscopic surgery when performed in joints, and thoracoscopic surgery when performed in the chest.

Because it causes less tissue damage than traditional surgery, keyhole surgery has several advantages, including the following:

  • A briefer hospital stay (in most cases)
  • Often, less pain after the operation
  • Earlier return to work
  • A tendency toward smaller scars

However, the difficulties of keyhole surgery often are underestimated by people undergoing the surgery and sometimes by surgeons. Because surgeons are using a video monitor, they are seeing only a two-dimensional view of the site on which they are operating. Also, the surgical instruments used have long handles and are controlled from outside of the person's body, so the surgeon may find that using them feels less natural than using traditional surgical instruments. For these reasons, keyhole surgery has potential disadvantages:

  • Keyhole surgery often takes longer than traditional surgery.
  • More importantly, especially when a procedure is new, errors are more likely to occur than with traditional approaches because of the complexity of keyhole surgery.

People also should know that although keyhole surgery may cause less pain than traditional surgery, pain still occurs, often more than anticipated.

Because keyhole surgery is technically difficult, people should do the following:

  • Choose a highly experienced surgeon
  • Establish that surgery is necessary
  • Ask the surgeon how pain will be treated

Preparing for the Day of Surgery

Various preparations are made in the days and weeks before surgery. It is often recommended that physical conditioning and nutrition be improved as much as possible, because good general health helps a person recover from the stress of surgery.

Alcohol and Tobacco Use: Eliminating or minimizing alcohol and tobacco use before undergoing surgery that involves general anesthesia can increase safety. Recent tobacco use makes abnormal heart rhythms more likely to develop during general anesthesia and impairs lung function. Excessive alcohol consumption can damage the liver, causing heavy bleeding during surgery and unpredictably increasing or decreasing the effect of the drugs used for general anesthesia. Alcohol consumption should be decreased gradually, however, because a sudden decrease before undergoing general anesthesia can cause harmful effects, such as fever and abnormalities of blood pressure or heart rhythm.

Doctors' Evaluations: The surgeon performs a physical examination and takes a medical history, which includes the person's recent symptoms, past medical conditions, past reactions to anesthetics (if any), use of tobacco and alcohol, infections, risk factors for blood clots, problems pertaining to the heart and lungs (such as cough or chest pain), and allergies. The person also is asked to list all drugs currently being taken. Nonprescription as well as prescription drugs must be disclosed because serious health problems could result. For example, the use of aspirin, which a person may consider too trivial to mention, can increase bleeding during surgery. Additionally, the use of supplements or herbal remedies (for example, ginkgo biloba or St. John's wort) should be disclosed as well because these may have effects during or after surgery.

The anesthesiologist may meet the person before the operation to review test results and identify any medical conditions that might affect the choice of anesthetic. The safest and most effective types of anesthesia may be discussed as well.

Tests: Tests performed before surgery (preoperative testing) may include blood and urine tests, an electrocardiogram, x-rays, and tests of lung capacity (pulmonary function tests). These tests can help determine how well the vital organs are functioning. If organs are functioning poorly, the stress of surgery or anesthesia can cause problems. Preoperative tests occasionally also reveal an inapparent temporary illness, such as an infection, which would require the postponement of surgery.

Blood Storage for Transfusion: People may wish to store their own blood in case a blood transfusion is needed during surgery. Using stored blood (autologous blood transfusion—see Blood Transfusion: Autologous Transfusion) eliminates the risk of infections and most transfusion reactions. A pint of blood can be withdrawn from the person and preserved until surgery. Blood should be withdrawn no more often than once weekly, and the last donation should probably be at least 2 weeks before surgery. The body replaces the missing blood during the weeks after the blood donation.

Decision Making: Sometime before the surgery, the surgeon obtains the person's permission to perform the operation, a process called informed consent. The surgeon discusses risks and benefits of the operation, as well as alternative treatments, and answers questions. The person reads and signs a form documenting consent. In cases of emergency surgery in which the person is unable to provide informed consent, doctors try to contact the family. Rarely, emergency surgery must proceed before the family is contacted.

A durable power of attorney for health care and a living will (see Legal and Ethical Issues: Living Will) should be prepared before surgery in case the person becomes unable to communicate or becomes incapacitated after surgery.

Oral Intake and Laxative Use: Because some of the drugs given during surgery may cause vomiting, people should generally not eat or drink anything for at least 8 hours beforehand. For outpatient surgery, people should not eat or drink anything after midnight. Specific guidelines should be given and vary depending on the kind of surgery. People should ask the doctor which of their regularly prescribed drugs should be taken before surgery. People undergoing surgery involving the intestines are given laxatives for a day or two before the operation.

Fingernails: Because the device that monitors the level of oxygen in the blood is attached to a finger, nail polish and artificial nails should be removed before going to the hospital. Then, this device can perform more accurately. Also, valuables should be left at home.

The Day of Surgery

Before most operations, a person removes all clothing, jewelry, hearing aids, false teeth, and contact lenses or eyeglasses and puts on a hospital gown. The person is taken to a specially designated room (the holding area) or to the operating room itself for final preparations before surgery. The skin that will be cut (operative site) is scrubbed with an antiseptic, which minimizes the number of bacteria, helping to prevent infection. A health care practitioner may shave the operative site. A plastic tube (catheter) is inserted in one of the veins of the hand or arm, through which fluids and drugs are given. A drug may be given intravenously for sedation. If an operation involves the mouth, intestinal tract, lungs or respiratory tract, or urinary tract, people are given one or more antibiotics within the hour before the operation to prevent infection (prophylaxis). This therapy also applies to people undergoing some other operations in which infections are particularly problematic (for example, joint or heart valve replacement).

In the Operating Room

In the Operating Room

The operating room provides a sterile environment in which the operating team can perform surgery. The operating team consists of the following:

  • Chief surgeon, who directs the surgery
  • One or more assistant surgeons, who help the chief surgeon
  • Anesthesiologist, who controls the supply of anesthetic and monitors the person closely
  • Scrub nurse, who passes instruments to the surgeon
  • Circulating nurse, who provides extra equipment to the operating team

The operating room typically contains a monitor that displays vital signs, an instrument table, and an operating lamp. Anesthetic gases are piped into the anesthetic machine. A catheter attached to a suction machine removes excess blood and other fluids, which can prevent surgeons from seeing the tissues clearly. Fluids given by vein, started before the person enters the operating room, are continued.

If the final preparations are done in the holding area, the person is then taken to the operating room. At this point, the person may still be awake, although groggy, or may already be asleep. The person is moved to the operating table, over which are specially designed surgical lights. Doctors, nurses, and other personnel who will be near or touching the operative site thoroughly scrub their hands with antiseptic soap, which minimizes the number of bacteria and viruses in the operating room. For surgery, they also wear scrub suits, caps, masks, shoe covers, sterile gowns, and sterile gloves. Before the surgery begins, a time out is held during which the surgical team confirms the following:

  • The person's identity
  • The correct procedure and side (if applicable)
  • Availability of all needed equipment
  • Prophylaxis to prevent infection or blood clots has been given (if needed)

Local, regional, or general anesthesia is given.

After Surgery

After the operation is completed and anesthesia begins to wear off, the person is taken to a recovery room to be closely watched for about 1 or 2 hours. Most people feel groggy when awakening, particularly after major surgery. Some people are nauseated for a short while. Some may feel cold.

Depending on the nature of the surgery and the type of anesthesia, a person may go home directly from the recovery room or be admitted to the hospital, sometimes in an intensive care unit (ICU).

Direct Discharge Home: A person being sent home must be

  • Thinking clearly
  • Breathing normally
  • Able to drink fluids
  • Able to urinate
  • Able to walk
  • Free of severe pain

People who have been given sedatives and then discharged need to be accompanied home by someone else and are not permitted to drive themselves. The operative site should be free of bleeding and unexpected swelling.

Hospitalization: People who are admitted to the hospital after surgery may awaken to find many tubes and devices in and on them. For example, there may be a breathing tube in the throat, adhesive pads on the chest to monitor the heartbeat, a tube in the bladder, a device attached to a finger to measure the level of oxygen in the blood, a dressing on the operative site, a tube in the nose or mouth, and one or more tubes in the veins.

Pain is expected after most operations and can almost always be relieved. Drugs that relieve pain (analgesics) can be given intravenously, by mouth, by injection into the muscle, or applied to the skin as a patch. If epidural anesthesia was used, the anesthesiologist may leave the plastic tube through which the anesthesia was given in the person's back. Opioid analgesics, such as morphine, can be injected through the tube. People staying in the hospital may be given a device that continuously injects an opioid analgesic into a vein, which also can deliver a small additional amount of analgesic when people press a button (patient-controlled analgesia). If pain persists, additional treatment can be requested (see Pain: Treatment). Repeated use of opioid analgesics often causes constipation. To prevent constipation, a stimulant laxative or stool softener may be given.

Proper nutrition is critical for rapid healing and minimizing the chance of infection. Nutritional needs increase after major surgery. If surgery makes eating impossible for more than several days, an alternative source of nutrition can speed recovery and prevent problems. People whose digestive tracts are functioning but who are otherwise unable to eat may be given nutrients through a tube placed into the stomach. Such a tube may be passed through the nose, mouth, or abdominal wall. Rarely, people who have had surgery of the digestive tract and cannot eat for extended periods may be given nutrients through one of the body's large veins (parenteral nutrition—see Undernutrition: Intravenous Feeding).

Complications: Complications such as fever, blood clots, wound problems, confusion, difficulty urinating or defecating, and muscle loss can develop during the days after surgery.

Fever has several common causes, including an inflammatory response to the trauma of an operation; a high metabolic rate that occurs with the stress of an operation, which causes the body to burn more calories and generate more heat; and infections, such as pneumonia, urinary tract infections, and infections at the operative site. Pneumonia may be prevented by periodically breathing forcefully in and out of a hand-held device (incentive spirometry) and coughing as needed.

Blood clots in the legs or pelvic veins (deep vein thrombosis) can develop, particularly if people lie immobile during and after surgery, have had surgery on their lower extremities or pelvic region, or both. The clots can dislodge and travel through the bloodstream to the lungs, where they can block blood from circulating through the lungs (pulmonary embolism). As a result, the oxygen supply to the rest of the body may be decreased, and sometimes blood pressure may fall. For certain operations after which blood clots are particularly likely, and for those people who are likely to have to lie still without much movement, doctors give preventive drugs that keep the blood from clotting (anticoagulants), such as low-molecular-weight heparin, or put compression stockings on the person's legs to improve blood circulation. However, anticoagulants may not be recommended for operations in which these drugs may cause bleeding. People should begin moving their limbs and walking as soon as it is safe for them to do so.

Wound complications may include infection and separation of the wound edges (dehiscence). To decrease the risk of infection, the surgical incision is dressed after surgery. The dressing includes a sterile bandage and usually includes an antibiotic ointment. The bandage keeps bacteria away from the incision and absorbs fluids that ooze from the incision. Because these fluids can encourage bacteria to grow and infect the incision, the dressing is changed often, usually daily. The wound is examined whenever the dressing is changed, sometimes more often. Occasionally, infection develops despite the best wound care. An infected site becomes increasingly painful 1 or more days after surgery and can become red and warm or drain pus or fluid. Fever can develop. If symptoms of dehiscence or infection develop, the doctor should be seen as soon as possible.

Delirium (confusion and agitation) can develop, particularly among the elderly. Drugs with anticholinergic effects (such as confusion, blurred vision, and loss of bladder control), opioids, sedatives, or antihistamine (histamine-2) blockers may contribute, as may too little oxygen in the blood. Drugs that can cause confusion should be avoided in the elderly when possible.

Difficulty urinating and difficulty defecating (constipation) can develop after surgery. Factors that contribute can include use of drugs with anticholinergic effects or opioids, inactivity, and not eating or drinking. Urine flow may become completely blocked, distending the bladder. Blockage can lead to urinary tract infections. Sometimes pressing on the lower abdomen while trying to urinate may relieve blockage, but often a catheter needs to be inserted into the bladder. The catheter is sometimes left in place and sometimes is removed as soon as the bladder is emptied. Frequently sitting up may help prevent blockage. People who develop constipation and whose surgery did not involve the intestinal tract can be given laxatives that stimulate the intestines, such as bisacodyl, senna, or cascara. Stool softeners such as docusate do not help.

Loss of muscle (sarcopenia) and strength occur in all people subject to prolonged bed rest. With complete bed rest, young adults lose about 1% of their muscle per day, but the elderly lose up to 5% per day because of lower levels of growth hormone, which is responsible for maintaining muscle tissue. Adequate amounts of muscle are important for recovery. Thus, people should sit up in bed, move, stand, and exercise as soon as and as much as is safe for them.

Discharge Home After Hospitalization: Before leaving the hospital, people are responsible for

  • Scheduling a follow-up visit with the doctor
  • Knowing what drugs to take
  • Knowing what activities to avoid or limit

Examples of activities that may need to be avoided temporarily include climbing stairs, driving a car, lifting heavy objects, and having sexual intercourse. A person should know what symptoms necessitate contacting the doctor before the scheduled follow-up visit.

Resuming normal activity during recovery from surgery should occur gradually. Some people need rehabilitation, which involves special exercises and activities, to improve strength and flexibility (see page 39). For example, rehabilitation after hip replacement surgery can involve learning ways to walk, stretch, and exercise.

Spotlight on Aging

In the mid-1900s, surgeons often hesitated to perform even simple operations on people over age 50. Times have changed! Now, more than one third of all operations in the United States are performed on people age 65 or over.

However, aging does increase the risk of complications during and after surgery. For example, older people are much more likely than younger people to develop delirium after surgery. They are also more likely to experience serious complications from bed rest that might occur after surgery. Among these complications are blood clots, loss of muscle, pneumonia, and urinary tract infections. The risk of death during or after surgery also increases with aging. More than three quarters of deaths in the period immediately after surgery occur in older people. Further, when emergency surgery is performed or when surgery involves the chest or abdomen, the risk of death increases in all age groups, but much more so for older people.

Although age itself is a risk factor, overall health and the presence of certain disorders increase surgical risk far more than age does. Having had a heart attack within 6 months of a surgical procedure is a particularly high risk factor, as is poorly controlled heart failure. Severe chest pain (angina) and undernutrition (which is common among institutionalized older people) increase the risk of surgery in older people. Lung problems, such as chronic obstructive pulmonary disease, are of some concern when determining the risks of surgery, particularly among smokers. Impaired kidney function and problems with mental function, such as dementia, also may increase the risk.

Certain surgical procedures pose more risk than others. For example, surgery involving the abdomen or chest, removal of the prostate, and major joint surgeries (such as hip replacement) rank highly on the list of risky procedures. Many procedures that older people commonly undergo, such as cataract surgery and surgery on small joints, pose lower risk. If an older person is generally well, most operations, including ones considered to be higher risk, can be performed safely.

When the risks of surgery are high, they still may be outweighed by the potential benefits. For example, surgery that involves some risk of death, such as repair of a large aortic aneurysm, should be considered if the person is expected to live for another 8 to 10 years, because such aneurysms increase the risk of death if they are not repaired. However, such surgery should probably be avoided if other illnesses limit life expectancy to only 1 to 2 years. When the risks of surgery are low, the low risk may be outweighed by a lack of benefit. For example, some people believe that the risk of even more minor procedures (for example, a skin graft of a pressure sore), which usually is very low, is still much too great to justify putting a person with advanced dementia through such an operation.

Last full review/revision February 2009 by Robert G. Johnson, MD

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