Appendix

Appendix
The appendix is a closed-ended, narrow tube up to several inches in length that attaches to the cecum (the first part of the colon) like a worm. (The anatomical name for the appendix, vermiform appendix, means worm-like appendage.) The inner lining of the appendix produces a small amount of mucus that flows through the open center of the appendix and into the cecum. The wall of the appendix contains lymphatic tissue that is part of the immune system for making antibodies. Like the rest of the colon, the wall of the appendix also contains a layer of muscle, but the layer of muscle is poorly developed.


Appendicitis and what causes appendicitis
Appendicitis means inflammation of the appendix. It is thought that appendicitis begins when the opening from the appendix into the cecum becomes blocked. The blockage may be due to a build-up of thick mucus within the appendix or to stool that enters the appendix from the cecum. The mucus or stool hardens, becomes rock-like, and blocks the opening. This rock is called a fecalith (literally, a rock of stool). At other times, the lymphatic tissue in the appendix might swell and block the appendix. After the blockage occurs, bacteria which normally are found within the appendix begin to invade (infect) the wall of the appendix. The body responds to the invasion by mounting an attack on the bacteria, an attack called inflammation. An alternative theory for the cause of appendicitis is an initial rupture of the appendix followed by spread of bacteria outside of the appendix. The cause of such a rupture is unclear, but it may relate to changes that occur in the lymphatic tissue, for example, inflammation, that lines the wall of the appendix.)
If the inflammation and infection spread through the wall of the appendix, the appendix can rupture. After rupture, infection can spread throughout the abdomen; however, it usually is confined to a small area surrounding the appendix (forming a peri-appendiceal abscess).
Sometimes, the body is successful in containing ("healing") the appendicitis without surgical treatment if the infection and accompanying inflammation do not spread throughout the abdomen. The inflammation, pain and symptoms may disappear. This is particularly true in elderly patients and when antibiotics are used. The patients then may come to the doctor long after the episode of appendicitis with a lump or a mass in the right lower abdomen that is due to the scarring that occurs during healing. This lump might raise the suspicion of cancer.

 Symptoms 
The main symptom of appendicitis is abdominal pain. The pain is at first diffuse and poorly localized, that is, not confined to one spot. (Poorly localized pain is typical whenever a problem is confined to the small intestine or colon, including the appendix.) The pain is so difficult to pinpoint that when asked to point to the area of the pain, most people indicate the location of the pain with a circular motion of their hand around the central part of their abdomen. A second, common, early symptom of appendicitis is loss of appetite which may progress to nausea and even vomiting. Nausea and vomiting also may occur later due to intestinal obstruction.
As appendiceal inflammation increases, it extends through the appendix to its outer covering and then to the lining of the abdomen, a thin membrane called the peritoneum. Once the peritoneum becomes inflamed, the pain changes and then can be localized clearly to one small area. Generally, this area is between the front of the right hip bone and the belly button. The exact point is named after Dr. Charles McBurney--McBurney's point. If the appendix ruptures and infection spreads throughout the abdomen, the pain becomes diffuse again as the entire lining of the abdomen becomes inflamed.


 Treatment
Once a diagnosis of appendicitis is made, an appendectomy usually is performed. Antibiotics almost always are begun prior to surgery and as soon as appendicitis is suspected.
There is a small group of patients in whom the inflammation and infection of appendicitis remain mild and localized to a small area. The body is able not only to contain the inflammation and infection but to resolve it as well. These patients usually are not very ill and improve during several days of observation. This type of appendicitis is referred to as "confined appendicitis" and may be treated with antibiotics alone. The appendix may or may not be removed at a later time.
On occasion, a person may not see their doctor until appendicitis with rupture has been present for many days or even weeks. In this situation, an abscess usually has formed, and the appendiceal perforation may have closed over. If the abscess is small, it initially can be treated with antibiotics; however, the abscess usually requires drainage. A drain (a small plastic or rubber tube) usually is inserted through the skin and into the abscess with the aid of an ultrasound or CT scan that can determine the exact location of the abscess. The drain allows pus to flow from the abscess out of the body. The appendix may be removed several weeks or months after the abscess has resolved. This is called an interval appendectomy and is done to prevent a second attack of appendicitis.