• The Appendix is a small, finger-like tube that hangs from the lower right side of the large intestine, i.e. the Caecum.
• It is a vestigial organ i.e. the purpose of the appendix is not known.
• Appendicitis is the most common general surgical emergency.
• The incidence of appendectomy appears to be declining due to more accurate preoperative diagnosis.
• Despite newer imaging techniques, acute appendicitis can be very difficult to diagnose.
Pathophysiology
Acute appendicitis is thought to begin with obstruction of the lumen
Obstruction can result from
1. Inspisated stool
2. Food matter or seeds
3. Tumours
4. Parasites or
5. Lymphoid hyperplasia
Mucosal secretions continue to increase intraluminal pressure
When the blockage occurs, the bacteria will invade the wall of the appendix and causing inflammation.
This progresses to gangrene of the appendix.
Perforation or rupture of the appendix may occur if there is no treatment.
Perforation may lead to peritonitis, sepsis, and death.
Exceptions exist in the classic presentation due to anatomic variability of the appendix
Appendix can be retrocaecal causing the pain to localize to the right flank
In pregnancy, the appendix can be shifted and patients can present with RUQ pain
In some males, retroileal appendicitis can irritate the ureter and cause testicular pain.
Pelvic appendix may irritate the bladder or rectum causing suprapubic pain, pain with urination, or feeling the need to defecate
Multiple anatomic variations explain the difficulty in diagnosing appendicitis
History
• Primary symptom: abdominal pain
• 1/2 to 2/3 of patients have the classical presentation
• Pain begins in the umbilical area that is vague and hard to localize
Associated symptoms:
a) anorexia,
b) nausea,
c) vomiting,
d) indigestion,
e) discomfort,
f) low-grade fever
g) inability to pass gas
h) change in normal bowel pattern
As the illness progresses, pain localizes to the right lower quadrant typically
Migration of pain from initial periumbilical to RLQ is characteristic of acute appendicitis
Anorexia is the most common of associated symptoms
Vomiting occurs in about ½ of the patients
Physical Exam
• Patients with acute appendicitis usually look ill and lie still in bed.
• Fever if present is usually mild(around 100ºF) and not associated with chills.
• Examination shows focal tenderness in the right iliac fossa with guarding
• The exact location of the pain is over the appendix and because of its variable position there is a difference in the site of the pain.
• The pain is usually at McBurney’s point (2/3 distance on the line connecting the umbilicus and the ASIS)
• Any movement, especially coughing can increase the pain (Dunphy’s sign)
• Pain on the right with palpation of the left (Rovsing’s sign)
Additional components that may be helpful in diagnosis:
• rebound tenderness,
• voluntary guarding,
• muscular rigidity,
• tenderness on rectal
• Psoas sign: place patient in L lateral decubitus and extend R leg at the hip. If there is pain with this movement, then the sign is positive.
• Obturator sign: passively flex the R hip and knee and internally rotate the hip. If there is increased pain then the sign is positive
• Once the appendix perforates the pain becomes more intense and more diffuse
• There may be rigidity of the abdomen
• The heart rate rises
• Temperatures rise >39°C
• Patient will need antibiotics and fluid resuscitation at this stage before induction of anaesthesia
“To know acute appendicitis is to know well the diagnosis of acute abdominal pain”
--Sir Zachary Cope
Diagnosis
• Acute appendicitis should be suspected in anyone with epigastric, periumbilical, right flank, or right sided abdominal pain who has not had an appendectomy
• Women of child bearing age need a pelvic exam and a pregnancy test.
• Very young, very old, pregnant, and HIV positive patients present atypically and often have delayed diagnosis
• High index of suspicion is needed in these groups to get an accurate diagnosis
Laboratory studies
• CBC: the WBC is elevated.
• >75% Neutrophils
• WBC count > 20,000 suggests gangrene or perforation of the appendix.
• Procalcitonin, CRP and ESR have been studied with mixed results.
• All other tests have limited value and may be used to exclude other diagnosis.
• Urine analysis
• abnormal urine analysis results are found in 19-40%
• Abnormalities include:
• Pyuria, (pus in urine)
• Hematuria (blood in urine)
• Bacteruria (bacteria in urine)
• Presence of >20 WBC’s per field should increase consideration of Urinary tract pathology
• Urinary pregnancy test
Radiography
1. Abdominal xrays
2. Barium meal
3. Barium enema
4. Ultrasonography of the abdomen & pelvis
5. CT Scans of the abdomen & pelvis
Xrays
· Calcified Appendicolith
· Small bowel obstruction
· Ureteric or renal calculi
· Perforations
Barium studies
· Non-filling of the appendix to fill is associated with appendicitis
· 20% normal appendices don’t fill
Ultrasonography
· >7mm
· Thick walled, non-compressible tubular structure
· In the right iliac fossa
· ? With an appendicolith
· Peri appendicular fluid
· Mass formation
Advantages of USG:
1. Highly sensitive and specific
2. Non-invasive
3. No radiation – therefore can be used in pregnancy and children
4. No preparation needed
5. Useful in excluding pelvic pathologies
Disadvantages of USG:
1. Operator dependant
2. Others cannot analyse images
CT Scan
• Commonly used
• CT findings increase with the severity of the disease
• >7mm with wall thickening
• Appendicoliths
• Fat stranding,
• Free fluid
• Phlegmon
• Abscess
Advantages of CT scan:
• Best choice based on availability and alternative diagnoses.
• CT has greater sensitivity, accuracy, & negative predictive value
• Even if appendix is not visualized, diagnose can be made with localized fat stranding in RLQ.
• Reduces the negative appendicectomy rate
Disadvantages of CT scan:
1. May be misleading, especially in the early stage of the disease
2. Can delay the diagnosis & intervention
3. Ionising Radiation
4. Contrast induced kidney damage
5. Allergic reaction to contrast
6. Aspiration pneumonitis
Diagnostic Laparoscopy
• Provides direct examination of the appendix and entire abdominal cavity
• Used in women of childbearing age where USG & CT fail to provide a diagnosis
• Helps treat other abdominal pathologies
Differential Diagnosis
A useful rule:
“Never place appendicitis lower than second in the differential diagnosis of acute abdominal pain in a previously healthy person.”
In pre-school children:
1. Intussusception
2. Meckel’s diverticulitis
3. Acute gastroenteritis
In School-aged children:
1. Acute mesenteric lymphadenitis
2. Inflammatory bowel disease
3. Constipation
In Adults:
1. Acute pyelonephritis
2. Acute colitis (Acute typhilitis)
3. Acute diverticulitis
4. Crohn’s disease
In Women of Child bearing age:
1. Pelvic inflammatory diseases
2. Tubo-ovarian abscesses
3. Ruptured ovarian cysts
4. Ovarian torsion
5. Ectopic pregnancy (Ruptured)
In the Elderly:
1. Diverticulitis
2. Bowel obstruction
3. Malignancies (GI & reproductive systems)
4. Ulcers
5. Cholecystitis
• Difficult to diagnose
• Present late therefore more complications.
• Fever is uncommon
• WBC counts may be normal
Treatment
Appendectomy is the standard of care
1. Open
2. Laparoscopic
Patients should be kept starving, given IV fluids, and preoperative antibiotics
Antibiotics are most effective when given preoperatively and they decrease post-op infections and abscess formation
Laparoscopic approach preferred as it is
associated with:
1. Shorter hospital stays
2. Less pain
3. Less bleeding
4. Smaller incisions
5. Less wound complications
6. Faster regaining of gut functioning
7. Less adhesions in the abdomen
8. Faster resumption of daily activities
Normal appearing appendix
• Occasionally we may get a normal appearing appendix at the time of surgery.
• Practice is to remove the appendix and then start a thorough search for other causes based on the patient’s symptoms.
• Meckel’s diverticulum is only diagnosed intra-operatively in a patient taken up for acute appendicitis. Very rarely diagnosed even on CT scan.
Perforated Appendix
• Grave disease in which patient can rapidly deteriorate.
• Need IV fluids and antibiotics pre-operatively
• Can become a
1. Localised abscess
2. Generalised peritonitis
Appendicular Abscesses
• Patients who present late with a lump and fever may benefit from non-operative management.
• It reduces complications and overall hospital stay.
• Large abscesses >4-6cm, with high fever benefit from abscess drainage
• Abscess drainage may be
1. Percutaneous USG or CT guided
2. Trans rectal or trans vaginal
Interval Appendicectomy
• After non-operative management adults should undergo colonoscopy or a Barium enema to rule out a tumour
• Interval Appendicectomy should be performed 6 – 12 weeks later.
• Interval Appendicectomy is associated with low morbidity and a short hospital stay.
• Procedure routinely performed in children with recurrent appendicitis.
• If the patient doesn’t respond to conservative management or is declining medically, emergent surgery needs to be carried out.
Please feel free to contact me here if you have any queries regarding appendicitis.
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