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1. Appendectomy for appendicitis is the most commonly
performed emergency operation in the world.
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2. Despite the increased use of ultrasonography, computed tomographic
scanning, and laparoscopy, the rate of misdiagnosis of appendicitis
has remained constant (15.3%), as has the rate of appendiceal rupture.
The percentage of misdiagnosed cases of appendicitis is significantly
higher among women than among men.
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3. Appendicitis is a polymicrobial infection, with some series reporting
up to 14 different organisms cultured in patients with perforation.
The principal organisms seen in the normal appendix, in acute appendicitis,
and in perforated appendicitis are Escherichia coli and Bacteroides
fragilis.
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4. Antibiotic prophylaxis is effective in the prevention of postoperative
wound infection and intra-abdominal abscess. Antibiotic coverage
is limited to 24 to 48 hours in cases of nonperforated appendicitis.
For perforated appendicitis, 7 to 10 days of treatment is recommended.
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5. Compared with younger patients, elderly patients with appendicitis
often pose a more difficult diagnostic problem because of the atypical
presentation, expanded differential diagnosis, and communication
difficulty. These factors contribute to the disproportionately high
perforation rate seen in the elderly.
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6. The overall incidence of fetal loss after appendectomy is 4% and
the risk of early delivery is 7%. Rates of fetal loss are
considerably higher in women with complex appendicitis than in those
with negative appendectomy and those with simple appendicitis. Removing
a normal appendix is associated with a 4% risk of fetal
loss and 10% risk of early delivery.
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7. Recent data on appendiceal malignancies from the Surveillance,
Epidemiology, and End Results program identified mucinous adenocarcinoma
as the most frequent histologic diagnosis, followed by adenocarcinoma,
carcinoid, goblet cell carcinoma, and signet-ring cell carcinoma.
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The appendix first becomes visible in the eighth week of embryologic development
as a protuberance off the terminal portion of the cecum. During
both antenatal and postnatal development, the growth rate of the
cecum exceeds that of the appendix, so that the appendix is displaced
medially toward the ileocecal valve. The relationship of the base
of the appendix to the cecum remains constant, whereas the tip can
be found in a retrocecal, pelvic, subcecal, preileal, or right pericolic
position (Fig. 30-1). These anatomic considerations
have significant clinical importance in the context of acute appendicitis. The
three taeniae coli converge at the junction of the cecum with the appendix
and can be a useful landmark to identify the appendix. The appendix
can vary in length from <1 cm to >30 cm; most appendices are
6 to 9 cm long. Appendiceal absence, duplication, and diverticula have
all been described.1–4
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For many years, the appendix was erroneously viewed as a vestigial organ
with no known function. It is now well recognized that the appendix
is an immunologic ...