Appendicitis is acute inflammation of the vermiform appendix. The appendix is a small ‘dead end’ pouch, like a little tube, that comes off the caecum. The caecum is the first part of the large intestine (large bowel) just before the colon. The small intestine digests and absorbs food. The parts of the food that are not digested begin to be formed into faeces (motions) in the caecum. The appendix is normally about 5-10 cm long and quite thin. The appendix appears to have no function. The reason it is there is a bit of a mystery.
Appendicitis is thought to result from obstruction of the appendiceal lumen, typically inflammation of the lymphoid, but occasionally also by fecalith (fecal stone), foreign body, or even worms. The obstruction leads to distention, bacterial overgrowth, ischemia or compromised blood flow, and inflammation. The inflamed appendix gradually swells and fills with pus. Eventually, if not treated, the swollen appendix might perforate (burst). This is very serious as the contents of the intestine then spill into the abdominal cavity. This can cause a serious infection of the membrane that lines the abdomen (peritonitis), or an abscess in the abdomen. So, if appendicitis is suspected, early treatment is best before it bursts.
Sign and Symptoms
The classic symptoms of acute appendicitis are upper stomach pain followed by brief nausea, vomiting, and loss of appetite; after a few hours, the pain shifts to the right lower quadrant. Pain increases with cough and motion. These symptoms are typically associated with low grade fever.
Unfortunately, the classic findings appear in < 50% of patients. Many variations of symptoms and signs occur. Pain may not be localized, particularly in infants and children. Sometimes diarrhea is the main symptom. In elderly patients and pregnant women, pain is less severe and local tenderness is less marked.
When classic symptoms and signs are present, the diagnosis is clinical. In such patients, delaying surgery only increases the likelihood of perforation and subsequent complications. In patients with atypical findings, imaging studies should be done without delay. The contrast-enhanced CT is proven to give accuracy in diagnosing appendicitis and can also reveal other causes of abdominal pain. However, in certain conditions, the CT scan is not applicable and the ultrasound would be the next best choice. The advantage of the ultrasound is it can be done quickly, non-invasive, and no radiation (a particular concern in children), however it is very operator-dependent, occasionally limited for diagnosis by the presence of bowel gas, and is less useful for recognizing non-appendiceal causes of pain.
The definitive diagnosis, of course is direct visualization of the inflamed appendix itself. Some surgeons choose laparoscopy for diagnosis as well as definitive treatment; it may be especially helpful in women with lower abdominal pain of unclear cause.
Other Conditions Mistaken as Appendicitis
Pain in the lower right quadrant of the abdomen often indicates appendicitis, but other conditions can cause pain in this area. They include:
- Inflammation of the lining of the stomach and intestines (acute gastroenteritis).
- Inflammation of the lymph nodes in the stomach (mesenteric adenitis).
- Pelvic inflammatory disease.
- Ectopic pregnancy.
- An ovarian cyst or ovarian torsion.
- Crohn’s disease.
- An inflamed pouch of tissue in the ileum of the small intestine (Meckel’s diverticulum).
- Bowel obstruction.
- Kidney stones.
- Urinary tract infection, including kidney infection.
The only treatment for appendicitis is surgery to remove your appendix (appendectomy). If you have appendicitis and do not have surgery in time, your appendix can burst. A burst appendix can cause serious problems. It’s best to remove the appendix before it bursts.
There are different types of surgery for appendicitis. Your surgeon may operate through a large cut (incision) in your belly or use a tool called a laparoscope to remove your appendix through a few smaller incisions. Either way, you may take antibiotics before your surgery, after your surgery, or both. There are advantages and disadvantages to each type of surgery. Talk with your surgeon about which type is best for you.
If your appendix does burst, you will need antibiotics. Surgery to remove a burst appendix may be more complicated.
Without surgery or antibiotics, mortality is > 50%. With early surgery, the mortality rate is < 1%, and the healing time is normally rapid and complete.