Acute Appendicitis

The appendix is a tubular, blind-ended, vestigial structure which is attached to the caecum. Anatomically the location of the appendix corresponds to the right iliac fossa which is at the lower right quadrant of our abdomen. The human appendix is hypothesised to have lost its original function through evolution.

 Some of the functions of the appendix are:

-immunological functions - it contains lymphoid follicles which secrete immunoglobulins

-it contains serotonins which are neuroendocrine hormones

-it has a bacteriological function where it helps to control the normal gut bacterias

-Surgical functions - where the appendix is used as an 'urinary conduit' in bladder reconstruction in bladder surgery & it can also be used as an 'appendicostomy' which can be used for antegrade colonic enema (wash-out of faeces) in patients with constipation.

The appendix lies in close proximity to the caecum (the beginning of our large intestines). Approximately 75% of the appendix lies behind the caecum (retrocaecal), 20% in the pelvis and the remaining 5% either pre- or post-ileal (infront or behind the small bowel).

Appendix attached to the caecum

Acute appendicitis is the inflammation of the appendix. It is the commonest acute surgical condition in the abdomen. It typically presents with an initial pain around the umbilical region which later migrates and localises in the right iliac fossa. Usually the patient will have a low grade fever, loss of appetite and nausea. There will be tenderness of the abdomen localised at the right iliac fossa which is typically described as at McBurney's point (2/3 along the line drawn between the umbilicus and the anterior superior iliac spine).
Severe cases of appenditis can present with severe abdominal pain, high spiking temperature & dehydration. This usually happens when there is a delay in diagnosis and the appendix perforates leading to purulent or faeculent peritonitis (contamination of the abdominal cavity with pus or faeces).

Other causes of a right iliac fossa pain are:
-urinary tract infection
-kidney stones (renal colic)
-Meckel's diverticulitis
-mesenteric adenitis (usually associated with flu)
-colonis diverticulitis (usually in elderly people)
-torsion of ovary
-ectopic pregnancy
-pelvic inflammatory disease
-intestinal obstruction

The treatment for acute appendicitis is appendicectomy (surgical excision of the appendix). This procedure was traditionally done as an open surgery but most surgeons are doing laparoscopic (minimally invasive) appendicectomies now. The complications of appendicetomy includes:
-wound infection (<5% risk)
-intra-abdominal abscess
-faecal fistula (leakage of faeces from the resected appendix stump)

The sequelae of acute appendicitis includes:
- Perforated appendix: - as a result of inflammation and ischaemia (reduced blood supply) to the appendix, the wall weakens and perforates. This will lead to localised or generalised, purulent or feaculent peritonitis. The patient will be more ill.
- Appendicular mass: - a swelling noted at the right iliac fossa which is a mass of omentum covering the inflammed appendix. This typically happens a few days after the initial episode of right iliac fossa pain when our body tries to wall of the inflammed appendix.
- Chronic appendicitis: - this usually occurs in patients who were treated with antibiotics or anti-inflammatories for a bout of lower abdominal pain. They develop a chronic grumbling right iliac fossa pain which is very vague. It is usully a diagnosis of exclusion.