Appendicitis In-depth Notes

Appendicitis Overview

Pathological Sequence

• Inflammation of the appendix mucosa:

  • Causes: Possible faecolith (hardened stool) or obstruction due to foreign body, lymphoid hyperplasia, or malignancy can lead to increased intraluminal pressure, ischemia, and inflammation of the appendix.

• Extension of symptoms:

  • Initial inflammation may progress to affect the serosa (visceral peritoneum), leading to localized pain in the right lower quadrant as the inflammation extends.

• Spread of inflammation:

  • If not treated, the inflammation can lead to gangrene of the appendix wall due to lack of blood flow, potentially causing perforation.

  • This can either:

    • Trigger a walling-off reaction (local abscess formation) that can help prevent the spread of peritonitis.

    • Result in inadequate walling-off, leading to diffuse peritonitis, which is a serious condition requiring immediate surgical intervention.

Clinical Manifestations of Acute Appendicitis

Cardinal Features:

• Abdominal pain:

  • Typically lasts less than 72 hours, often starting in the epigastric region before migrating to the right iliac fossa.

• Vomiting:

  • Occurs 1-3 times and is often one of the early symptoms, indicating irritation of the gastrointestinal tract.

• Facial flush:

  • May be observed due to autonomic nervous system activation in response to pain.

• Tenderness:

  • Notable tenderness is typically localized in the right iliac fossa upon physical examination.

• Fever:

  • May range from 37.3 to 38.5°C, reflecting systemic inflammation.

• Rectal examination:

  • Anterior tenderness is often present but should be approached with caution, as it can cause patient discomfort.

• Urinary tract infection:

  • Should be excluded utilizing microscopy of urine samples for nitrites or significant white cells/bacteria, as overlap in symptoms can occur.

Diagnosis: Alvarado Scoring System

Scoring for Diagnosis of Appendicitis:

• Pain migration:

  • From central abdomen to right iliac fossa (Score: 7), with a characteristic shift that can aid diagnosis.

• Anorexia (Score: 1)

  • An early symptom often reported alongside pain.

• Nausea/vomiting (Score: 2)

  • Contributes to the scoring and patient assessment.

• Tenderness in right iliac fossa (Score: 1)

  • Directly correlates with the affected area of the appendix.

• Rebound tenderness (Score: 2)

  • A positive sign indicating peritoneal irritation.

• Raised temperature (≥ 37.5°C) (Score: 10)

  • Significant fever suggests a high likelihood of appendicitis.

• Raised leucocyte count (≥ 210 × 10^9/L) (Score: 10)

  • A strong indicator of infection.

• Neutrophilia (≥ 75%) (Score: 10)

  • Also acts as a marker for appendicitis.

Key Notes on Scoring:

• While the Alvarado scoring system is subjective, it helps in clinical decision-making. However, it may show unreliable results in certain populations or situations.

• A score of 4 or less indicates a low likelihood of appendicitis; thus, hospital admission is not necessary unless symptoms worsen significantly.

• It is noted that in appendicitis patients, 40% may show rising scores over time, confirming its progressive nature and aiding in monitoring.

Historical Perspectives on Appendicitis Diagnosis

• Lawson Tait:

  • Conducted the first successful appendicectomy in 1880, paving the way for surgical intervention in appendicitis.

• Key diagnostic signs developed by historical figures include:

  • Mandel: Pain at percussion over the right iliac fossa, an indicator of inflammation.

  • Bloomberg: Rebound tenderness upon palpation, showing irritation of the peritoneum.

  • Rovsing: Pain in right iliac fossa when palpating the left iliac fossa, indicative of generalized peritoneal irritation.

  • Lapinki-Jaworski: Psoas sign indicating irritation of the iliopsoas muscle.

  • Voskresenski: Observation of skin hyperaesthesia related to localized inflammation.

  • Dieulafoiy triad: Featuring pain, tenderness, and skin hyperaesthesia specifically in the right iliac fossa.

  • Ochsner-Sherren: Identification of an appendix mass with surgery deferred for 6 weeks allowing resolution of inflammation.

Iacobovici Triangle Definition

• Boundaries:

  • Defined by three anatomical landmarks:

  • Bi-spinal line

  • Lateral margin of the rectus abdominis muscle

  • Spino-umbilical line in the right iliac fossa, which aids in surgical navigation.

Differential Diagnoses for Acute Appendicitis

Main Differential Diagnoses:

• Urinary Tract Infection:

  • Should be excluded if no nitrites or significant white cells or bacteria are present on urine microscopy, as they can mimic appendicitis symptoms.

• Mesenteric Adenitis:

  • Frequently seen in children, more often viral in origin, and can be associated with previous upper respiratory infections.

• Large Bowel Disorders:

  • Constipation: Can lead to similar pain but typically does not accompany fever.

  • Diverticulitis: May present with localized pain and is often confirmed during surgery.

• Gynaecological Disorders:

  • Mittelschmerz: Ovulatory pain that is brief in duration, typically without signs of infection.

  • Salpingitis: Presents with lower abdominal pain and abnormal discharge, necessitating thorough examination for diagnosis.

  • Ovarian Cyst Issues: Such as cyst torsion or hemorrhage, can also mimic appendicitis symptoms requiring careful evaluation.

• Small Bowel Pathology:

  • Meckel's diverticulum: Rare but can present with symptoms similar to appendicitis, needing differential diagnosis.

• Pancreatitis:

  • Pain is typically central but may radiate to the iliac fossa; check serum amylase if diagnosis is unclear, as it promotes differential diagnosis.

Appendectomy Procedure

1. Skin Incision for Open Appendectomy:

   • Classical (Gridiron) incision from the umbilicus to McBurney's point, providing access to the appendix.

   • Cosmetic (Lanz) skin incision can be performed for a more aesthetically pleasing outcome.

2. Removing the Appendix:

   • A "two-layer" anastomosis is created for effective closure:

   • The appendix base is tied off before removal to avoid spillage of infectious material.

   • The stump is inverted using a purse-string suture to prevent residual infection.

3. Peritoneal Toilet:

   • If pus is present during the procedure, thorough swabbing and suctioning of the pelvic area are carried out to reduce the risk of postoperative infection.

4. Closure:

   • Use absorbable sutures for deeper layers (e.g., polygactin):

   • Continuous suture for peritoneum.

   • Interrupted sutures for the internal oblique muscle.

   • Continuous sutures for external oblique aponeurosis.

   • The skin is closed subcuticularly in cases with no signs of infection; if there is, it may be left open for delayed closure to minimize the risk of infection.

Laparoscopic Appendectomy

• Surgical setup includes careful trocar placement in the umbilicus for laparoscopic access.

  • Continuous monitoring of the abdominal cavity and visualization of the appendix location during the procedure to minimize complications and optimize surgical outcomes.