2. What is it?
• Acute inflammation of the vermiform appendix
• Vermiform means resembling or having form of a worm
• Rare in infants and becomes increasingly common in childhood and
early adult life, reaching a peak incidence in the teens and early 20s.
3. When & How appedix
develops
• Development In the sixth week of human embryonic life
• Outpouchings from the caudal limb of the midgut.
• Adult positionOf the base the appendix on the posterior medial wall,
just below the ileocecal valve. Position of the base of the appendix is
constant.
• The tip of the appendix has variable
positions.
The vermiform appendix
4. Surgical anatomy
average length of the appendix is 6 to 9 cm
Vascular supply from the appendicular branch of the ileocolic
artery And vein
Innervation sympathetic elements the superior mesenteric plexus
(T10-L1) and parasympathetic elements via the vagus nerves.
three layers: the outer serosa, the muscularis layer, which is not
well defined and may be absent, the submucosa and mucosa.
Lymphoid aggregates occur in the submucosal layer and may
extend into the muscularis mucosa
5. What causes acute
appendicitis?
No unifying hypothesis regarding the aetiology
Decreased dietary fibre and increased consumption of refined
carbohydrates may be important.
Majority of cases luminal obstruction, either by a
faecolith
parasite
Tumor
stricture is found in the
6. How it occurs
proximal obstruction of the appendiceal lumen
produces a closed-loop obstruction, and continuing normal secretion by
the appendiceal mucosa
rapidly produces distension
Distension stimulates the nerve endings of visceral afferent stretch
fibers
producing vague, dull, diffuse pain in the mid-abdomen or lower
epigastrium.
Distension increases from continued mucosal secretion and from rapid
multiplication of the resident bacteria of the appendix
7. This causes reflex nausea and vomiting, and the visceral pain
increases.
As pressure in the organ increases, venous pressure is exceeded.
Capillaries and venules are occluded but arterial inflow continues,
resulting in engorgement and vascular congestion.
The inflammatory process involves the serosa of the appendix and
in turn the parietal peritoneum. This produces the characteristic
shift in pain to the right lower quadrant.
The mucosa of the appendix is susceptible to impairment of
blood supply; thus, its integrity is compromised early in the
process, which allows bacterial invasion.
8. How it presents
&
Clinical assessments
Symptoms of appendicitis
● Periumbilical colic
● Pain shifting to the right iliac fossa
●Anorexia
● Nausea
Clinical signs in appendicitis
● Pyrexia
● Localised tenderness in the right iliac fossa
● Muscle guarding
● Rebound tenderness
Signs to elicit in appendicitis
● Pointing sign
● Rovsing’s sign
● Psoas sign
● Obturator sign
11. Alvarado score
predictive of acute appendicitis score of 7 or more
equivocal score (5–6)
abdominal ultrasound or contrast-enhanced CT examination further
reduces the rate of negative appendicectomy