Appendicitis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Farwa Haideri [2]

The first description of appendicitis dates back to the early 1500s from a French doctor and prolific writer, Jean Francois Fernel, in “Universa Medicina”. However, Appendicitis was first officially described in 1886 by Reginald J. Fitz of Harvard University. Since then, the appendectomy has become one of the most common surgical procedures. The laparoscopic appendectomy was invented in the 1980s, and has led to reduced length of hospital stay, a decreased risk of infection, and a reduction in post-operative pain.

• The earliest known drawing of the appendix was in 1492 by the great artist and scientist, Leonardo da Vinci.^[1]
• Berengarius Carpus, a professor of surgery at Pavia and Bologna, gave the first description of the appendix in 1522.^[2]
• Physician Gabriele Fallopius was the first to compare the appendix to a worm in 1561.^[2]
• In 1579, Johann Bauhin proposed the theory that the appendix provided function in intrauterine life as a storage for feces.^[2]

• The first description of appendicitis is thought to date back to the early 1500s by French doctor and prolific writer, Jean Francois Fernel, in “Universa Medicina”.^[3]

• During the late 1600s, Lorenz Heister was the first surgeon to perform post-mortem sections of appendicitis and gave an unequivocal description of a perforated appendix and abscess.^[4]
• Francois Melier suggested surgical removal of the appendix in 1827, although his paper was largely ignored.
• Guillaume Dupuytren, a leading surgeon in Paris, gave strong opposition to Melier’s suggestion and was convinced that the cause of right lower quadrant inflammatory disease was due to the cecum.^[5]
• During the 1840s, four well-known physicians, Thomas Hodgkin, Richard Bright, Thomas Addison, and Voltz all pointed towards the appendix as the source of the disease.
• Reginald. J. Fitz, an anatomic pathologist from Harvard University, described appendicitis in his paper “Perforating Inflammation of the Vermiform Appendix” on June 18th, 1886 to the Association of American Physicians.
• Reginald. J. Fitz was the first person to provide a clear description of the pathology, diagnosis, treatment of appendicitis and also coined the term appendicitis.^[6]
• The first actual surgical removal of the appendix was done by Caudius Amyand at St. Georges Hospital in London, when he removed a perforated appendix found in a scrotal hernia.

• Charles McBurney from the College of Physicians and Surgeons in New York City pioneered the diagnosis and early operative intervention of appendicitis.^[7]
• The McBurney point was described in 1889, which is one-third of the way laterally from the anterior superior iliac spine to the umbilicus on the right side of the abdomen.
• The McBurney incision was coined in 1894.
• In 1902, A.J. Oschner advocated for a non-operative treatment of peritonitis.^[8]

• The laparoscopic appendectomy surgery was invented by Kurt Semm in 1980.

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Farwa Haideri [2]

Appendicitis may be classified based on based on the duration of symptoms, based on etiology of obstruction and based on whether appendix has been perforated or not.

Appendicitis may be classified based on the etiology of obstruction into:^[1]

• Infectious appendicitis – Obstruction of appendicial lumen is due to infectious inflammation^[2].
• Fibrosis appendicitis- Scar tissue from a previous surgery can lead to obstruction.
• Fecaliths appendicitis – Hard fecal masses block the outlet of appendix
• Neoplasic appendicitis – Carcinoid, adenocarcinoma, or mucocele is responsible for increased secretions resulting in blockage.
• Parasitic appendicitis- In endemic areas obstruction of the appendicial lumen is due to parasitic load.
• Calculic appendicitis
• Lymphoid hyperplasic appendicitis Obstruction of lumen due cell hyperplasia.

Appendicitis may be classified based on perforations or non-perforations^[3].

Perforating appendicitis

• The appendiceal wall has been compromised due to pressure and inflammation and the intraluminal contents have leaked out into the peritoneal cavity.
• Increases in incidence with age and is associated with the following types of bacterial infiltration:^[4]
  • Escherichia coli
  • Peptostreptococcus
  • Bacteroides fragilis
  • Pseudomonas species

Non-perforating appendicitis

• Inflammation is contained within the appendix; no intraluminal contents have leaked out.

Appendicitis may be classified based on duration of symptoms into:

• Symptoms have existed less than 48 hours.

Non acute appendicitis

•  Symptoms have existed for days or weeks, or have recurred several times.

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Farwa Haideri [2]

Common causes of appendicitis include obstructive fecaliths, parasitic or bacterial infections of the appendix, trauma, and lymphadenitis.

Common causes of appendicitis include:^[1]

• Foreign bodies
• Trauma
• Intestinal worms
• Lymphadenitis
• The occurrence of an obstructing fecalith
  • The occurrence of a fecalith in the appendix seems to be attributed to a right sided fecal retention reservoir in the colon and a prolonged fecal transit time.^[2]
• Low dietary fiber intake
  • Several studies offer evidence that a low fiber intake is involved in the pathogenesis of appendicitis.^[3][4][5]
  • This link between low fiber intake and appendicitis is in accordance with the occurrence of a right sided fecal reservoir and that dietary fiber reduces fecal transit time.^[6]
• Appendicolith
• Ascariasis
• Bacteroides
• Taenia infection

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Farwa Haideri [2]

Appendicitis must be differentiated from other causes of abdominal pain such as acute gastroenteritis and luminal obstruction. Age group can be another factor used to differentiate appendicitis.

• Appendicitis can be differentiated from other diseases that cause lower abdominal pain and fever like diverticulitis, inflammatory bowel disease, colon cancer, cystitis, and endometritis.^{[1][2][3][4][5][6]}

• Since appendicitis presents as the general symptom of abdominal pain, appendicitis must be differentiated from other diseases and disorders causing similar pain and symptoms. This differentiation can be done according to four categories: surgical, urological, gynaecological, and medical.^[7]

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Farwa Haideri [2]

Appendicitis is one of the most prominent causes of acute abdominal pain. It is a common disease in both Europe and America, and each year, approximately 100 people per 100,000 exhibit developing cases of appendicitis. Younger people, in the age group of 10-19, have a higher chance of developing appendicitis. Males are more likely than females to develop appendicitis. Caucasians are more likely to develop appendicitis than non-Caucasians.

• One out of every 15 people (7%) will develop acute appendicitis in their lifetime.^[1]

• In Europe and America, the incidence of appendicitis is about 100 per 100,000 patients per year.^[2]
• The peak incidence occurs between the second and third decades of life.^[1]
• Appendicitis is one of the most frequent diagnoses for emergency department visits resulting in hospitalization among children aged 5–17 years in the United States.^[3]

• In the United States, the highest incidence of appendicitis is found in the age group of 10-19 years old.^[4]
• Appendicitis is more uncommon in age extremities (less than 5 years and greater than 50 years of age).^[1]

• Males present with symptoms of appendicitis 1.4 times as much compared to women across all age groups.^[5]

• Appendicitis rates are 1.5 times higher in Caucasians than in other ethnicities.^[1]

• Appendicitis is more common in industrialized countries in Europe and America where diets are more consistent with highly refined foods that are low in dietary fibers.^[1]

• In developing countries, the chances of appendicitis are lower because of the typical agrarian diet that is composed of more high-fiber foods as opposed to refined food.^[1]

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Farwa Haideri [2]

Identifying risk factors that predict the likelihood of complications is a crucial step in managing appendicitis. Appendicitis is most common among people in the age group of 10 to 30 years old. Appendicitis leads to more emergency abdominal surgeries than any other cause.

• The most common cases of appendicitis occur between the ages of 10 and 30 years, and it is the most likely cause of acute abdomen pain in the United States, with a 5-20% chance of lifetime risk.^[1][2]

Common risk factors for adults include:^[2]

• Steroid use
• Diabetes
• Chronic obstructive pulmonary disease

Common risk factors in children include:^[1]

• Appendicitis results in the most common need for emergency abdominal surgery.
• A family history of appendicitis increases the child’s risk, especially in males.
  • Male children with cystic fibrosis are at an even higher risk.

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Farwa Haideri [2]

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Farwa Haideri [2]

Appendicitis can lead to death if peritonitis develops from the rupturing of the appendix and is left untreated. Acute appendicitis that is evaluated and treated early with an appendectomy generally leads to no further complications and a patient’s full recovery.

• The symptoms of appendicitis typically develop shortly after inflammation of the appendix.
• Without treatment, the patient will likely develop symptoms of pain, starting centrally (in the periumbilical region) before localizing to the right iliac fossa in the right lower quadrant of the abdomen.
  • They will also experience loss of appetite, diarrhea, fever, nausea, and vomiting.
  • During the final stage of the untreated disease process, the appendix will rupture, and this may eventually lead to death if peritonitis develops.^[1]

Most complications that can develop as a result of the treatment of appendicitis include:^[2]

• Abnormal connections between abdominal organs or between these organs and the skin surface (fistula)
• Abscess
• Rupture
• Infection of the surgical wound
• Peritonitis

• Most patients with appendicitis recover quickly with surgical treatment (laparoscopic appendectomy), but complications can occur if treatment is delayed or if peritonitis occurs.
• Recovery time depends on age, condition, complications, and other aspects in the patient’s history (including amount of alcohol consumption).
  • It usually takes between 10 and 28 days to recover completely.
• For young children (around 10 years old), recovery takes three weeks.
• Typical acute appendicitis responds quickly to appendectomy and occasionally will resolve spontaneously.
  • If appendicitis resolves spontaneously, it remains controversial whether an elective interval appendectomy should be performed to prevent a recurrent episode of appendicitis.
• Atypical appendicitis (associated with suppurative appendicitis) is more difficult to diagnose and is more apt to be complicated, even when operated on early.
  • In either condition, prompt diagnosis and appendectomy yield the best results with full recovery usually occurring in two to four weeks.
• Mortality and severe complications are unusual but do occur in some cases of appendicitis, especially if peritonitis develops and is left untreated.^[2]

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