What is an appendectomy?

Indications and Procedures

The appendix, more correctly named the vermiform appendix, is a hollow tube of muscle attached to the pouchlike beginning of the large intestine (the cecum) and closed at the end farthest from this point of attachment. It does not serve a known purpose and is thought to be a disappearing vestige of an organ that once had a purpose. Hence the appendix is called a vestigial organ.

A vermiform appendix exists only in humans and other primates. In humans, it is approximately 7.6 to 10.2 centimeters (3 to 4 inches) long and 1.3 centimeters (0.5 inches) in diameter. The cavity of the appendix (its lumen) is narrowest at the point of attachment to the cecum, and the muscular walls of the organ normally contract periodically to expel into the cecum both mucus made by the appendix and intestinal contents that may have accidentally entered the lumen.

When the narrow opening of the appendix into the cecum is blocked so as to prevent expulsion of mucus or fecal material, the organ becomes infected, a condition called appendicitis
. The most frequent obstructions found in appendix openings are fecaliths. These objects are hardened pieces of fecal matter that entered the appendix from the large intestine. Swelling of the inner walls of the appendix as a result of other causes (such as bacterial infection) can also begin such a blockage.

Following blockage, the events leading to appendicitis usually occur in the following order. First, fluids and mucus secreted by the cells lining the walls of the appendix collect in the blocked organ. This makes the appendix swell, causing the blood vessels that feed the organ’s tissues gradually to close off. In the absence of an adequate blood supply, the tissue begins to die. At the same time, bacteria originating in the cecum grow vigorously in the affected appendix, increasing the inflammation and swelling of the dying organ.

Quick and appropriate treatment by surgical removal of the infected appendix—appendectomy—is required at this time. Otherwise, the walls of such an appendix, one weakened by tissue death and subjected to increasing pressure by both bacterial growth and the buildup of mucus, may burst. When this happens, the contents spill into the abdominal cavity and infect the membranes that line it. Such infection, peritonitis, is very serious and painful. In most cases, however, the use of antibiotics will keep peritonitis from becoming fatal.

Where open-surgery appendectomy is required, the patient is usually given a general anesthetic and a 5.1- to 7.6-centimeter(2- to 3-inch) incision is made directly over the site of the appendix. Where laparoscopic surgery is performed, three small incisions (1.2 centimeters or 0.5 inches long) will be made in the abdomen; a small camera called a laparoscope is then passed through one incision and surgical tools are inserted into the other incisions. In both procedures, the surgeon then ties off and cuts the blood vessels that feed the organ. Next, the appendix is tied off near its connection to the cecum and carefully cut free without allowing its contents to enter the abdominal cavity. The operation usually takes under an hour and produces minor postoperative discomfort for a few days. The surgical risks of this procedure are very slight. Some of the benefits of laparoscopic surgery include less scar tissue and a shorter duration of postoperative discomfort.

Uses and Complications

Acute infection of the appendix, requiring its surgical removal, is the most frequent cause for abdominal surgery. It is most likely to occur between the ages of eight and thirty, but no age group is exempt. Acute appendicitis is often symptomized by initial generalized abdominal pain that rapidly becomes localized. The pain, which can be quite severe and which is felt whenever the patient moves or coughs, frequently occurs in the lower-right quadrant of the abdomen (an area between the navel and the front edge of the right hipbone). This location is common because many appendixes are located in the underlying abdominal cavity. The appendix may be found, however, in any of several other positions. Hence, the pain can occur elsewhere in the abdomen, and acute appendicitis may be mistaken for other abdominal disorders
.

Other symptoms useful in diagnosing acute appendicitis are nausea and vomiting, increased pulse rate, and mild fever. In addition, the patient’s white blood count will often increase from the normal range of 7,000 to 10,000 per cubic millimeter to 25,000. Doctors can also use computed tomography (CT) scanning for diagnostic purposes. When symptoms of acute appendicitis occur, medications should not be given unless quick access to surgical facilities is available. For example, cathartics are a poor treatment choice because they stimulate intestinal contractions that may accelerate intestinal rupture. Similarly, the use of hot water bottles to relieve pain is inappropriate because it may also speed rupture. In cases of acute pain, the patient should be taken to a hospital emergency room as quickly as possible.

The dangers associated with appendicitis arise from its neglect. Peritonitis is rarely fatal because of the timely use of antibiotics. Much more serious are localized abscesses of the abdominal wall and the inflammation of the veins that carry blood away from the kidneys (septic pyelophlebitis). Both of these problems can be fatal, even when extensive and aggressive antibiotic therapy is carried out.

Bibliography

"Appendectomy—Laparoscopic Surgery." Health Library, November 30, 2012.

"Appendectomy—Open Surgery." Health Library, November 7, 2012.

"Appendectomy: Surgical Removal of the Appendix." American College of Surgeons, 2012.

Krahenbuhl, L. Acute Appendicitis: Standard Treatment or Laparoscopic Surgery? New York: Karger, 1998.

Papadakis, Maxine, et al., eds. Current Medical Diagnosis and Treatment 2013. New York: McGraw-Hill Medical, 2012.

Porter, Robert S., et al., eds. The Merck Manual of Diagnosis and Therapy. 19th ed. Whitehouse Station, N.J.: Merck Research Laboratories, 2011.

Zinner, Michael J., et al., eds. Maingot’s Abdominal Operations. 12th ed. New York: McGraw-Hill, 2012.