Contents
History
- First described by Reginald Fitz on his paper to the first meeting of the Association of American Physicians in 1886 entitled, ‘Perforating inflammation of the vermiform appendix‘
- Charles McBurney described clinical manifestation of acute appendicitis including point of maximum tenderness in right iliac fossa.
Etiology
Risk Factors:
- Western-type diet
- ↓ Dietary fibres
- ↑ Refined carbohydrates
Non-obstructive causes:
- Bacterial proliferation (aerobic + anaerobic)
Obstructive causes:
- Faecolith/Appendicolith (adults) (M/C cause): Inspissated faecal material + calcium phosphates + bacteria + epithelial debris + (rarely) foreign material
- Tumour:
- Primarily carcinoma caecum
- Lymphoid hyperplasia (children)
- Intestinal parasites: Oxyuris vermicularis (pinworm)
Pathophysiology
Obstruction/infection
↓
Lymphoid hyperplasia
↓
Luminal hyperplasia
↓
↑ Intraluminal pressure
↓
Lymphatic drainage obstruction
↓
Oedema + mucosal ulceration
Bacterial translocation to the submucosa
↓
2 outcomes:
↓
Resolution or Progression
↓
(Progression)
↓
Venous obstruction + Ischaemia
Bacterial invasion through muscularis propria & submucosa
↓
ACUTE APPENDICITIS
Ischaemic necrosis of appendix wall
↓
Peritoneal contamination
↓
GANGRENOUS APPENDICITIS
↓
Walling off of peritoneal contamination by greater omentum & small bowel adherent to the inflamed appendix.
↓
PHLEGMONOUS MASS or PARACAECAL ABSCESS
Histopathology:
- Diagnostic criteria for acute appendicitis:
- Presence of neutrophils in smooth muscle layer
Presentation
- Periumbilical colic
- Pain shifting to right iliac fossa
- Anorexia
- Nausea
Diagnosis
Physical examination:
- Low-grade pyrexia
- Localized tenderness in the right iliac fossa
- McBurney’s point: Point of maximum tenderness located 1⁄3 distance from right anterior superior iliac spine
- Limitation of respiratory movement
- Pointing Sign: Patient asked to point where pain began and show its migration (Usually Periumbilical region → right lower abdomen)
Perforation → peritonitis:
- Muscle guarding
- Rebound tenderness
- Psoas sign: Pain on passively extending the thigh of a patient lying on his/her side with knees extended, or asking the patient to flex his thigh at the hip so patient lies with right hip flexed for pain relief
- Due to inflamed appendix lies on psoas muscle
- Rovsing’s sign: Deep palpation of left iliac fossa causes pain in right iliac fossa
- Obturator test/Zachary Cope: Pain in hypogastrium from spasm of obturator internus when right hip is flexed and internally rotated
Ultrasonography:
Imaging modality of choice in children
- Filling defect in appendix
- Appendicular wall thickness ≥ 6 mm
- Luminal distention, lack of compressibility
CECT abdomen:
Imaging modality of choice in adults
Alvarado score:
Clinical scoring system used in the diagnosis of appendicitis. The score has 6 clinical items and 2 laboratory measurements with a total 10 points.
Differential diagnosis:
Children | Adults | Adult female | Elderly |
Gastroenteritis | Regional enteritis | Mittelschmerz | Diverticulitis |
Mesenteric adenitis | Ureteric colic | Pelvic inflammatory disease | Intestinal obstruction |
Meckel’s diverticulitis | Perforated peptic ulcer | Pyelonephritis | Colonic carcinoma |
Intussusception | Torsion of testes | Ectopic pregnancy | Torsion appendix epiploicae |
Henoch–Schönlein Purpura (HSP) | Pancreatitis | Torsion/rupture of ovarian cyst | Mesenteric infarction |
Lobar pneumonia | Rectus sheath hematoma | Endometriosis | Leaking aortic aneurysm |
Management
Surgical management: Appendectomy
- Laparoscopic Appendectomy
- Open procedure
- Indications:
- Extensive infection/abscess
- Perforated appendix
- Obesity
- Dense scar tissue from previous surgery
- Difficulty viewing though laparoscope
- Bleeding problems
- Indications:
Summary