#15 – Appendicitis



  • 1st described in the late 1400s and 1st published in 1544 by Jean Fernal
  • 1st appendectomy was performed in 1736 on an 11yo boy
  • 233/100,000 population
  • May occur throughout life, but is most common age group is 10-19yo and slightly more common in men
  • Badass of the Millennium goes to….Leonid Rogozov.  He was the only physician on a Soviet team in Antarctica in 1961 and performed an appendectomy…on himself…and survived (Article here)

Leonid Rogozov performing an appendectomy on himself – 1961

Anatomy of the Appendix



  • Located where the taenia coli converge at the base of cecum
  • Average length 6-9cm, outer diameter 3-8mm, and luminal diameter 1-3mm
  • Arterial supply is from appendicular branch of the ileocolic artery
  • The attachment of the base of the appendix is constant, but the tip may be positioned:
    • Retrocecal (most common)
    • Subcecal
    • Preileal
    • Postileal
    • Pelvic



  • Follows traditional predictable series of events for inflammation of a hollow visceral organ:
    • Inflammation
      • Most commonly by an obstruction
        • Fecalith, calculi, lymphoid hyperplasia, infection, mass
        • Causes a closed-loop obstruction
    • Distention
      • Normal secretion and bacterial overgrowth
        • Causes visceral nerve pain
      • Luminal pressure > perfusion
        • Involves the serosa
          • Causes parietal pain
    • Perforation
      • As areas of ischemia progress and pressures increase, perforation may occur
        • May be contained (localized) or cause peritonitis
      • Although this progression is predictable, the time frame may be variable
        • Perforation may occur anywhere from 24-48 hours after symptom onset


  • Abdominal pain occurs first
    • Starts as diffuse, periumbilical
    • Appendix position may alter pain location
  • Nausea and vomiting then follows
  • Anorexia (Negative Cheeseburger Sign)
  • Last is migratory pain to RLQ (50-60%)

Physical Examination

  • Often non-specific as appendix position, time course of illness, and patient anatomy may obscure findings
  • Classic physical exam findings include:
    • McBurney’s Point Tenderness
      • Maximal tenderness 3cm from ASIS, or 1/3rd the distance from ASIS to umbilicus
  • 4
    • Rovsing’s Sign
      • Palpation or rebound pressure of LLQ causes RLQ pain
    • Psoas Sign (retrocecal)
      • Pain in RLQ when ipsilateral hip is extended or flexed against resistance
    • Obsturator Sign (pelvic)
      • Pain in RLQ with internal rotation of ipsilateral hip with flexed knee
    • Guarding and peritoneal signs may be seen with perforation


Laboratory Studies

  • CBC with differential and CRP are needed for the scoring systems, but are not very specific

Pretest Probability Scoring Systems

  • Alvarado Score
    • Developed in 1986 and modified in 1994
  • Appendicitis Inflammatory Response (AIR) Score
    • Developed in 2008
  • Pediatric Appendicitis Score
    • Developed in 2002

Screen Shot 2016-06-15 at 12.39.04 PM

  • Interpretation
    • Alvarado Score
      • 0-3 – low probability (discharge)
      • 4-6 – indeterminate (image or admit)
      • ≥ 7 – high probability (admit or surgery)
    • AIR Score
      • 0-4 – Low probability (discharge)
      • 5-8 – Indeterminate (image or admit)
      • ≥ 9 – high probability (admit or surgery)
    • PAS
      • < 3 – low probability (discharge)
      • 3-7 – indeterminate (image or admit)
      • ≥ 8 – high probability (admit and consult)

Radiographic Imaging

  • Imaging is generally reserved for indeterminate cases or special populations (children, women, elderly) as clinical examination is just as effective as imaging in ruling-out appendicitis
  • Computed Tomography
    • IV contrast
    • Findings suggesting appendicitis:
      • ≥ 6mm diameter
      • Appendiceal wall thickening ≥ 2mm
      • Periappendiceal fat stranding
      • Appendicolith
  • Ultrasound
    • Study of choice in children and pregnant women and becoming study of choice in adults
    • Findings suggestive of appendicitis:
      • Aperistaltic, noncompressible, dilated (> 6mm) appendix
      • Distinct appendiceal wall layers
      • Echogenic prominent pericecal fat
      • Periappendiceal fluid collection
      • Target appearance on axial section
Metanalyses Comparing CT to US in Appendicitis

Metanalyses Comparing CT to US in Appendicitis


  • Nonoperative Management
    • Several studies have looked at antibiotic management of uncomplicated appendicitis and found:
      • Up to 53% of antibiotic-only management still required surgery within 48hr
      • Antibiotic-only patients had lower pain scores and quicker return to work
      • Up to 37% of antibiotic-only patients required surgery for recurrent appendicitis within 2 years
      • Most recent study (APPAC Trial, JAMA, 2015) did meet prespecified criterion for noninferiority
      • May be an options for special populations
        • Poor surgical candidates, patients who refuse surgery
    • As for now, there isn’t enough good data to support routine, nonoperative management for uncomplicated appendicitis
  • Operative Management
    • Uncomplicated
      • Urgent (12-24hr) vs Emergent (< 12hr)
        • No difference in outcomes
        • 7
    • Complicated (perforation with abscess)
      • Sick or with generalized peritonitis = emergent surgery
      • Limited peritonitis
        • Antibiotics, bowel rest, percutaneous drainage
        • Interval appendectomy after improvement in clinical course
    • Laparoscopic vs Open Appendectomy
      • Laparoscopic > open in regards to patient outcomes
    • Complications
      • Wound infections
      • Organ space infections
      • Stump appendicitis

Cottage Physician


Diagnosis and Management of Peritonitis


  1. Williams GR. Presidential Address: a history of appendicitis. With anecdotes illustrating its importance. Ann Surg. 1983;197(5):495-506.
  2. Buckius MT, Mcgrath B, Monk J, Grim R, Bell T, Ahuja V. Changing epidemiology of acute appendicitis in the United States: study period 1993-2008. J Surg Res. 2012;175(2):185-90.
  3. Liang MK, Andersson RE, Jaffe BM, Berger DH. The Appendix. In: Brunicardi F, Andersen DK, Billiar TR, Dunn DL, Hunter JG, Matthews JB, Pollock RE. eds. Schwartz’s Principles of Surgery, 10e. New York, NY: McGraw-Hill; 2014. http://accesssurgery.mhmedical.com/content.aspx?bookid=980&Sectionid=59610872. Accessed June 14, 2016.
  4. Raahave D, Christensen E, Moeller H, Kirkeby LT, Loud FB, Knudsen LL. Origin of acute appendicitis: fecal retention in colonic reservoirs: a case control study. Surg Infect (Larchmt). 2007;8(1):55-62.
  5. Birnbaum BA, Wilson SR. Appendicitis at the millennium. Radiology. 2000;215(2):337-48.
  6. Temple CL, Huchcroft SA, Temple WJ. The natural history of appendicitis in adults. A prospective study. Ann Surg. 1995;221(3):278-81.
  7. Andersson RE. Meta-analysis of the clinical and laboratory diagnosis of appendicitis. Br J Surg. 2004;91(1):28-37.
  8. McBurney C. Experience with early operative interference in cases of disease of the vermiform appendix.  NY State Med J. 1889;50:676.
  9. Alvarado A. A practical score for the early diagnosis of acute appendicitis. Ann Emerg Med. 1986;15(5):557-64.
  10. Kalan M, Talbot D, Cunliffe WJ, Rich AJ. Evaluation of the modified Alvarado score in the diagnosis of acute appendicitis: a prospective study. Annals of the Royal College of Surgeons of England. 76(6):418-9. 1994.
  11. Andersson M, Andersson RE. The appendicitis inflammatory response score: a tool for the diagnosis of acute appendicitis that outperforms the Alvarado score. World journal of surgery. 32(8):1843-9. 2008.
  12. De castro SM, Ünlü C, Steller EP, Van wagensveld BA, Vrouenraets BC. Evaluation of the appendicitis inflammatory response score for patients with acute appendicitis. World J Surg. 2012;36(7):1540-5.
  13. Samuel M. Pediatric appendicitis score. Journal of pediatric surgery. 37(6):877-81. 2002.
  14. Park JS, Jeong JH, Lee JI, Lee JH, Park JK, Moon HJ. Accuracies of diagnostic methods for acute appendicitis. The American surgeon. 2013;79(1):101-6.
  15. Whitley S, Sookur P, McLean A, Power N. The appendix on CT. Clinical radiology. 2009;64(2):190-9.
  16. Appendicitis. http://radiopaedia.org/articles/appendicitis. Accessed on June 14th, 2016.
  17. Sallinen V, Akl EA, You JJ. Meta-analysis of antibiotics versus appendicectomy for non-perforated acute appendicitis. Br J Surg. 2016;103(6):656-667.
  18. Varadhan KK, Neal KR, Lobo DN. Safety and efficacy of antibiotics compared with appendicectomy for treatment of uncomplicated acute appendicitis: meta-analysis of randomised controlled trials. BMJ. 2012;344:e2156.
  19. Salminen P, Paajanen H, Rautio T. Antibiotic Therapy vs Appendectomy for Treatment of Uncomplicated Acute Appendicitis: The APPAC Randomized Clinical Trial. JAMA. 2015;313(23):2340-8.
  20. Society of American Gastrointestinal and Endoscopic Surgeons. Guidelines for Laparoscopic Appendectomy.  http://www.sages.org/publications/guidelines/guidelines-for-laparoscopic-appendectomy/.  Accessed on June 15th, 2016.
  21. Blackborne LH. The Appendix. In: Surgical Recall. 6th Philadelphia, PA. LWW.

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