The appendix is a tube shape organ that arises from the caecum of the large intestine. Surgical removal of the appendix is a common procedure and its absence does not have any adverse effects.
Appendicitis describes inflammation of the appendix. It usually occurs when the opening between the appendix and caecum becomes blocked. The blockage is most commonly caused by faecal matter that has entered the appendix and hardened (a faecolith). Blockages may also be caused by swelling of the immune (lymphoid) tissues within the wall of the appendix, mucous that has thickened and hardened within the appendix, parasites, other inflammatory bowel problems such as Crohn’s disease and tumours. Blockage results in increased pressure within the appendix, which impedes blood flow, and bacterial growth causing infection and further inflammation. The combined effect is tissue injury and possibly death of the appendix wall. The appendix may then rupture, releasing bacteria, pus and/or faeces into the surrounding abdominal cavity.
The classical symptoms of appendicitis are vague central abdominal pain that becomes more severe and shifts to the right lower abdomen, loss of appetite, nausea and vomiting. These symptoms are not always present. Symptoms and examination findings may vary depending on the position of the appendix.
The diagnosis of appendicitis is often made on the symptoms and examination findings. Blood tests are a useful aid in diagnosis. Urine tests, a pregnancy test and imaging such as an ultrasound or CT scan may also be used to exclude other conditions and support the clinical diagnosis. A ‘diagnostic laparoscopy’, or ‘keyhole surgery’, may be recommended if it is unclear whether the findings are due to appendicitis or another condition.
Surgical removal of the appendix is the standard treatment for appendicitis. This is usually performed laparoscopically, using a thin telescope attached to a light source and video camera (laparoscope) inserted through a small incision near the belly button, and other instruments inserted via several other small incisions in the lower abdomen. Occasionally the appendix cannot be removed by this method and it is necessary to make a larger incision to remove the appendix (the open technique).