Medical Articles

The Appendix


Anatomy & Physiology

  • Length: 1-25cm (average 8cm)
  • Position: Variable
  • Blood supply: Appendicular artery
  • Nerve supply: Autonomic nervous system
  • Function: ? Immune surveilance of gut

Acute Appendicitis

INTRODUCTION

  • Very common
  • Lifetime risk 7%
  • Peak incidence 10-30 years
  • Potentially lethal condition

PATHOGENESIS

  • Lumiinall obstructiion vs priimary iinffectiious etiiollogy
  • Primary infectious etiology - temporall & geographiic clusteriing - Organiisms isolated → typiical coloniic flora Possible rolle off llymphoiid hyperpllasiia
  • Lumiiallobstructino (most widell accepted) - lymphoid hyperplasia,, fecaliths,, increased concretions
  • Obstructiion → mucous production → stasis → Bacterial overgrowth → supperation → increased intraluminal pressure → ischaemiia/inffectiion → perforatiion → localized → abscess → free → generalized periitoniitiis

CLINICAL FINDINGS

TYPICAL

  • History
    • Abdominal pain
    • Anorexia
    • Nausea & vomiting

Physical examination (varies with stage of disease progression)

  • Early
    • low grade fever, mild tachycardia-
    • tenderness in RIF (maximal at McBurney’s point) progresses to peritoneal irritation
  • Late
    • free perforation → generalized peritonitis ± septic shock
    • localized → appendix mass/abscess

Atypical presentation

  • Atypiicall posiitiion
  • Decreased iimmuniity
  • Speciiffiic siigns (not so iimportant)
  • Rovsiing’s siign
  • Obturator siign
  • Illeopsoas siign

Laboratory findings

  • Raiised lleucocyte count (average 15000)
  • 10% normall lleucocyte count
  • ↑CRP
  • Uriine
  • Pregnancy test

Imaging studies

  • Mostlly to excllude other pathollogiies + diiagnosiis iis uncertaiin
  • Diifffferentiiate between appendiix mass + abscess
  • CXR
  • AXR
  • Abdominalulltrasound
  • AbdominalCT scan

Diagnosis + differential diagnosis

Cornerstone is history + physical examination

  • Abdominal pain localising to RIF
  • Anorexiia
  • Nausea + vomitiing
  • Low grade fever

Routine special investigations additive Special imaging studies → diagnosis in certain mass in RIF Diagnosiis uncertain → admit patiient re-evalluate 4 hrly

Differential diagnosis

Pain in RIF

  • Gynaecological problems
    • PID
    • Ectopic pregnancy
    • Ovarian pathology
    • endometriosis
    • Mittelschmertz
  • Urinary tract pathology –
    infection stones
  • Mesenteric lymphadenitis
  • Disease of terminal ileum
  • Caecal carcinoma
  • Meckel’s diverticulitis
  • Many other

Complications

  • Perforation – localized – free
  • Pylephlebitis
  • Liver abscess
  • Septic shock → Multi-organ failure → death (0.1%)

Treatment

  • Surgical → Appendicectomy → Open → Laparoscopic
  • Antibiotics – cover gram negative bacteria and anaerobes

Special subgroups

Appendix abscess + mass Abscess tends to be more tender, higher fever (typical swinging fever), higher WBC. Differentiate with ultrasound Mass → IV-antibiotics + interval appendicectomy 6 weeks later

VS

Early appendicectomy (only if experienced) Abscess → Extra peritoneal drainage of abscess (± appendectomy – only if experienced) → IV-antibiotics + interval appendicectomy 6 weeks later

Normal appendix at surgery

  • Exclude other pathology
  • To remove appendix or not

Post-op complications

  • Early
    • Wound infection
    • Intra-abdominal abscess
    • Leakage from appendix stump
  • Late
    • Adhesive band obstruction
    • Infertility