Introduction and Epidemiology

Background

Acute appendicitis is a common and considered as emergency illness and thus immediate treatment needed. it has high morbidity and any delay of the diagnosis can be fatal. It is mildly hard to diagnose acute appendicitis since there is no single sign, clinical features, or diagnostic test that accurately can be used to confirm the diagnosis of acute appendicitis.

Epidemiology

United States:  7% of US population with strong association of family history with mortality rate of 0.2-0.8%

International:  mostly acute appendicitis is high in poor country in which their citizens consume less fibre diet. this because it is believed that high fibre-diet can reduce the feces viscosity, and decrease the incidence of bowel obstruction.

Causes

        1) Obstruction of appendiceal lumen

a)    Fecalith (stool that enters the appendix hardens, 
becomes rock-like, and blocks the lumen)

b)   Gallstone

c)    Tumor

d)   Ball of worms (oxyuriasis vermicularis)

      2) Trauma

a)    Rupture of the appendix –>spread of bacteria outside

the appendix-> periappendiceal abscess

Risk Factors

1.    Low dietary fiber

a)    Dietary fiber can decrease the viscosity of fecesàdecrease bowel transit timeàdiscourage formation of fecaliths

2.    Gender

a)    The risk is approximately 1.4 times greater in male than in female

3.    Age

a)    Occur in all age groups but incidence of appendicitis gradually rises from birth, peaks in the late teen years, and gradually declines in the geriatric years.

4.    Infection

a)    Gastrointestinal infections such as amebiasis, bacterial gastroenteritis, mumps, coxsackievirus B and adenovirus

Signs and Symptoms

APPENDICITIS or ABDOMINAL CRAMP

Which and which you are having??

How you know that you are having appendicitis and not just simply an abdominal cramp?

Below are a list of signs and symptoms that appear when you are succumb to appendicitis...

• Increasing sharp and severe pain at the right iliac fossa (lower abdomen)
• Diffuse, radiating pain
• Pain worsening when walking or coughing

• Nausea and vomiting associated with loss of appetitie

• Low grade fever with chills and rigor

• Constipation

If you or someone around you are presented with such signs and symptoms, DO NOT HESITATE...

DO CALL this emergency number (9-9-9) for HELP ...

Confirmatory Signs

What signs of appendicitis that can lead the doctor to a diagnosis of appendicitis?

• Rovsing's sign :  Palpation of left lower quadrant causes pain in right lower quadrant

• Psoas sign (aka Obraztsova's sign) : Pain on extension of right thigh, relieved by flexing the hip

• Obturator's sign : Pain in hypogastrium on internal rotation of right thigh

• Duphy's sign : Increase pain in right lower quadrant on coughing
• Kosher's sign : Pain in epigastrium on shifting to right iliac region
• Rosenstein's sign : Increase pain in right iliac region when lying on the side
• Bartomier-Michelson's sign : Increase pain in right iliac region when lying on side then lying on supine position during palpation
• Aure-Rozanova's sign : Increase pain in right petite triangle ( lumbar triangle) during palpation with finger
• Blumberg sign : aka rebound tenderness - pain upon removal of pressure from the abdomen

Pathogenesis

Appendicitis is inflammation of appendix which located in right lower abdomen.It is supplied by appendicular artery which is a branch of ileocolic artery.Mostly appendicitis is due to compromised blood supply due to obstruction of its lumen and this will increase ability of bacteria to invade the appendix which found in the gut normally.

Obstruction of the appendix lumen by faecolith, enlarged lymph node, worms, tumour, or indeed foreign objects, will increase intra-luminal pressure, which causes the wall of the appendix to become distended.
Normal mucus secretions continue within the lumen of the appendix, thus causing further build up of intra-luminal pressures in the appendix. This in turn leads to the occlusion of the lymphatic channels, then the venous return, and finally the arterial supply becomes affected.

Reduced blood supply to the wall of the appendix due to increase in intra-luminal pressure will cause the appendix gets little or no nutrition and oxygen. It also cause the appendix has  little or no supply of white blood cells and other natural fighters of infection that normally  found in the blood .This will cause the bacteria which normally found in gut available to the appendix.

Once the bacteria reach the appendix,it will multiply and this will lead inflammation process.This will worsen the obstruction of appendix lumen. This leads to necrosis and perforation of the appendix. Pus formation occurs when nearby white blood cells are recruited to fight the bacterial invasion. The pus that form is a combination of dead white blood cells, bacteria, and dead tissue .

When the content of the appendix like faecolith, pus and mucus secretions are  released into the general abdominal cavity due to perforation or rupture of affected appendix, this will cause  peritonitis

Morphology

 Early stage of acute appendicitis  

Scant neutrophilic exudate throughout the mucosa, submucosa and muscularis propria. Subserosal vessels will become congested and often with perivascular neutrophilic infiltrate. The inflammation transforms the normal glisterning serosa into a dull, granular and red.

Late acute appendicitis 

Dense neutrophils infiltration and fibropurulent serosal exudates over the serosa.Abscess formation with ulceration and suppurative necrosis occur within the wall. Subsequently, acute gangrenous necrosis will occur if there is green-black gangrenous necrosis through the wall extending to the serosa and immediately followed by appendix rupture.

Picture (a) and (b) shows acute appendicitis with neutrophils infiltration throughout mucosa, submucosa and muscalaris layers at different magnification.

Picture above shows the enlargement of appendix and  red inflamed mucosa with an irregular luminal surface.