Appendicitis

Inflammation of the vermiform appendix
Most cases are idiopathic.

1. Lumen: mucosal appendicitis
   • Foreign material
   • Faeces
   • Worms: strongyloides, ascaris lumbricoides
   • Parasites: oesophagostomiasis
2. Wall: transmural appendicitis
   • Infection: Viral (CMV, adenovirus), bacterial (TB, yersinia), amoebae, schistosomes
   • Inflammation: UC, crohn's, pseudomembranous colitis
   • Ischaemia: ischaemic colitis, congenital stricture, iatrogeni
3. Outside wall: Serosal appendicitis
   • Ovaries - salpingitis/oophritis
   • Endometriosis
   • Diverticular disease

Presentation

1. Clinical findings
   • Periumbilical colicky pain (visceral peritoeneum)
   • Migrates to RIF (parietal peritoneum)
2. Specific features
   • McBurney's point pain
   • Rosving's sign: Deep palpation of RIF causes pain in RIF - confused visceral peritoneum (also positive in bladder, uterus, descending colon, fallopian tubes, ovaries inflammation)
   • Psoas sign: flexed right hip where appendix is lying over psoas muscle
   • Rectal tenderness: from pelvic appendix

Indications

• Emergency - acute appendicitis
• Elective - "interval" appendiciectomy after intial conservative treatment (of appendix mass)

Open Procedure

1. GA + Antibiotics + supine position
2. Access appendix
   • McBurney's incision (90' to imarginary line) / Lanz incision (cosmetically better) / High up in RUQ in children
   • Skin, fat (campers fascia), scarpa's fascia
   • Incise external oblique aponeurosis in line of fibres, expose internal oblique (if too medial will see rectus sheath)
   • Split internal oblique fibres transversely, enlarge defect
   • Pick up peritoneum between 2 clips, incise with scalpel - turbid fluid indicates appendicitis (send this off to microbiology)
   • Identify caecum (has teniae) and deliver into wound [enlarge incision if difficult/impossible to deliver]
3. Remove appendix
   • Hold appendix with 2 tissue forceps (Babcocks)
   • Divide mesoappendix (hold up to light to see blood vessels)
   • Apply purse string (buries appendix stump) with 2/O
   • Crush appendix base (facilitates secure knot tying) and ligate proximally with O suture.
   • Remove appendix, bury stump by tightening purse string
   • Suck out free fluid, wash out peritoneal cavity
4. Close wound in layers

Laproscopic Appendicectomy

Especially young female patients - where diagnosis uncertain, imaging has failed to exclude gynaecological cause.

1. GA / Possible conversion to open
2. Establish pneumoperitoneum 
   • Trendelburg position
   • Infraumbilical incision
   • Open peritoneum under direct vision
   • Insert trochar
   • Insufflate gas
3. Inspect appendix
   • 5mm port RIF under direct vision
   • 5mm port LIF
   • Grasp caecum and move towards spleen
   • Aspirate free fluid (send for cytology)
4. Remove appendix
   • Grasp appendix with forceps
   • Dissect from mesentry using hook diathermy introduced through right port
   • Ligate at base using pre-tied Vicryl ligature + second distal to first one
   • Divide and remove under direct vision
5. Peritoneal lavage
6. Close fascial defects with absorbable sutures + steri-strips to skin

If appendix normal - look for other causes:

• Gynae: ovaries, fallopian tubes, ectopic pregnancy
• Gut: meckel's, sigmoid diverticulitis
• Paediatric: look for mesenteric adenitis

Insert drain if abscess present

Complications

• Increased risk of right hernia