Acute Appendicitis

Abstract

Appendicitis remains the most common cause of an acute abdomen with 250,000 appendectomies performed annually in the United States. Appendicitis most frequently affects younger patients and is slightly more common in men than in women. The appendix is a blind-ended structure extending off the bowel lumen at the transition from the small to large intestine. The pathophysiology of appendicitis is luminal obstruction; however, the cause of obstruction varies. In the pediatric population, lymphoid hyperplasia is a common cause of appendiceal occlusion. In adults, fecal inspissation, plant seeds, or tumor may all cause obstruction, with the former comprising the vast majority of cases. Luminal obstruction leads to edema of the bowel wall, leading to venous congestion, which in turn generates further edema. Eventually, arterial insufficiency, ischemia, necrosis, and perforation will follow.