Epidemiology

• Prevalence: most common congenital gastrointestinal tract anomaly

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Etiology

• The omphalomesenteric duct (vitelline or vitellointestinal) is a patent tubular structure connecting the yolk sac to the alimentary tract in the embryo.
• The duct is normally obliterated by the 6–7th week of intrauterine life.
• Incomplete obliteration of the omphalomesenteric duct → persistence of the proximal (intestinal) segment of the duct → Meckel diverticulum
• There may be two types of mucosal lining
  • Native ileal mucosa
  • Ectopic mucosa
    • Most common: acid-producing gastric mucosa (∼ 60%)
    • Other types include pancreatic, colonic, and duodenal mucosa.

Tip

Similar to Urachal abnormalities

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Pathophysiology

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Clinical features

• Asymptomatic
  • Most common manifestation
• Symptomatic
  • Lower gastrointestinal bleeding (most common feature)
    • Presence of ectopic gastric mucosa or pancreatic tissue → acid or enzyme secretion within the diverticulum → ileal ulceration → bleeding
    • Can manifest as:
      • Hematochezia
        • Indicates a brisk hemorrhage
      • Tarry stools
        • Indicate a slow hemorrhage
      • Currant jelly stools
        • Indicate intussusception with bowel ischemia

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Diagnostics

Meckel scintigraphy scan (Meckel scan): a noninvasive nuclear medicine imaging technique using radiolabelled technetium (^99mTc), which is preferentially absorbed by the gastric mucosa and can identify ectopic gastric mucosa

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Treatment

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