Appendicitis and Appendectomy
Medical Author: Dennis Lee, M.D.
Medical Editor and Revising Author: Jay W. Marks, M.D.
Appendicits or Not?
Appendicitis? Maybe Not...
The surgeon faced with a patient suspected of having appendicitis always must consider and look for other conditions that can mimic appendicitis. Among the conditions that mimic appendicitis are:
- Meckel's diverticulitis
- Pelvic inflammatory disease
- Inflammatory diseases of the right upper abdomen
- Right-sided diverticulitis
- Kidney diseases
What is the 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 muscle is poorly
developed.
What is 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
may 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 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 line 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.
What are the complications of appendicitis?
The most frequent complication of appendicitis is perforation. Perforation of
the appendix can lead to a periappendiceal abscess (a collection of infected pus)
or diffuse peritonitis (infection of the entire lining of the abdomen and the
pelvis). The major
reason for appendiceal perforation is delay in diagnosis and treatment. In
general, the longer the delay between diagnosis and surgery, the more likely is
perforation. The risk of perforation 36 hours after the onset of symptoms
is at least 15%. Therefore,
once appendicitis is diagnosed, surgery should be done without unnecessary
delay.
A less common complication of appendicitis is blockage of the intestine. Blockage occurs when the
inflammation surrounding the appendix causes the intestinal muscle to stop
working, and this prevents the intestinal contents
from passing. If the intestine above the blockage begins to fill with liquid and
gas, the abdomen distends and nausea and vomiting may occur. It then may be
necessary to drain the contents of the intestine through a tube passed through
the nose and esophagus and into the stomach and intestine.
A feared complication of appendicitis is sepsis, a condition in which
infecting bacteria enter the blood and travel to other parts of the body. This
is a very serious, even life-threatening complication. Fortunately, it occurs
infrequently.
Next: What are the symptoms of appendicitis? »
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