Meckel diverticulum

Rule of 2s

• Present in about 2% of people
• Approximately 2 feet proximal to the ileocecal valve
• Roughly 2 inches long
• Male:female ratio about 2:1
• Often symptomatic before age 2 years
• Only about 4% become symptomatic
• Robbins, Cotran & Kumar Pathologic Basis of Disease, p. 726

Ectopic tissue

Main presentations

1. Painless lower gastrointestinal bleeding
   • Typical in children
   • Maroon or dark red stool, sometimes melena
   • Usually from acid-related ileal ulceration adjacent to ectopic gastric mucosa.
2. Intestinal obstruction
   • Volvulus around a fibrous vitelline band
   • Intussusception, with the diverticulum as a lead point
   • Internal herniation or entrapment by a mesodiverticular band
   • May present with colicky pain, vomiting, and distension.
3. Diverticulitis or perforation
   • Mimics acute appendicitis: right lower quadrant pain, fever, and tenderness.
4. Littre hernia
   • A Meckel diverticulum within an inguinal or femoral hernia sac.

• Schwartz's Principles of Surgery, 11th ed., pp. 1273-1274
• Sleisenger and Fordtran's Gastrointestinal and Liver Disease, section “Meckel Diverticulum”

Diagnosis

• Painless bleeding in a child: Technetium-99m pertechnetate scan, often called a Meckel scan, detects ectopic gastric mucosa.
• Pain, obstruction, or inflammation: CT or ultrasound may help, but diagnosis can remain difficult.
• Capsule endoscopy or enteroscopy may sometimes identify a bleeding diverticulum. Merck diagnostic approach

Treatment

• Symptomatic Meckel diverticulum: surgical removal, either diverticulectomy or segmental ileal resection if there is bleeding ulceration, ischemia, inflammation, perforation, or tumor concern.
• Incidentally found, asymptomatic diverticulum: removal is individualized rather than automatic.

High-yield distinction