Meckel’s diverticulum

Summary

Introduction

• Meckel’s diverticulum is an outpouching (diverticulum) of all three layers of bowel wall (true diverticulum) in the terminal ileum.
• Meckel’s diverticulum is the most common congenital GI tract anomaly.
• This condition arises due to failure of the vitelline duct to obliterate during the 7th week of gestation (persistence of the vitelline duct, omphalomesenteric duct, in the small intestine).
• Most cases are asymptomatic. However, Meckel's diverticulum can present during the first two years of life with bleeding, volvulus, intussusception, or obstruction (mimics appendicitis).
• Diagnosis is achieved by Meckel’s scan.

Epidemiology

• The prevalence of Meckel diverticulum is usually noted to be approximately 2% of the population.
• It is usually located in the lower portion of the small intestine.
• Complications are found in about 5% of the population with this anomaly.

Etiology

• Meckel’s diverticulum results from incomplete obliteration of the vitelline duct (leading to the formation of a true diverticulum of the small intestines).

Clinical Presentation

• Meckel’s diverticulum is mostly asymptomatic (normal abdominal exam).
• Painless (rectal bleeding) hematochezia (due to the presence of gastric/pancreatic tissue).
• It is an important cause of lower GI bleeding in infants and children.
• Intussusception (leading point).
• Meckel’s diverticulum can mimic acute appendicitis.
• Entrapment of the Meckel’s diverticulum inside a hernia (called Littre’s hernia).

Diagnosis

• Technetium-99m pertechnetate radioisotope or Meckel’s scan (mucus-secreting cells of the ectopic gastric mucosa take up pertechnetate allowing visualization of the Meckel’s diverticulum).
• It is most commonly discovered as an incidental finding on laparotomy.

Differential Diagnosis

• Intussuception.
• Appendicitis.
• Hirschsprung disease.

Treatment

• Surgery is reserved for symptomatic cases (laparoscopic or open surgical removal).

Complication

• Hemorrhage (most common).
• Diverticulitis.
• Perforation.