What are the typical presentations and complications of Meckel's (Meckel's diverticulum) diverticulum?

Meckel's Diverticulum: Clinical Characteristics and Presentations

Meckel's diverticulum is a true diverticulum that is asymptomatic in most cases, commonly presents with gastrointestinal bleeding in children rather than adults, and is found in approximately 2% of the population.

Epidemiology and Anatomy

• Meckel's diverticulum is the most common congenital anomaly of the small intestine 1
• It represents a remnant of the omphalomesenteric duct 2
• Prevalence is approximately 2% of the population, not 5-10% 3, 1
• It is a true diverticulum, containing all layers of the intestinal wall, not a false diverticulum 2

Clinical Presentation

• Most cases (approximately 96%) remain asymptomatic throughout life 3
• Lifetime risk of developing symptoms or complications is only about 4.2% 3
• The risk of complications decreases with age, approaching zero after age 70 3
• Symptomatic presentations vary by age group:

In Children

• Gastrointestinal bleeding is the most common presentation in children 4
  • Usually presents as painless rectal bleeding
  • Caused by peptic ulceration from acid secretion by ectopic gastric mucosa
• Intestinal obstruction is the most common complication (41% of symptomatic cases) 4
  • Often due to intussusception, with the diverticulum serving as a lead point
  • Volvulus can also occur

In Adults

• Intestinal obstruction is more common than bleeding in adults 3, 5
  • Can be due to volvulus, adhesions, or intussusception
• Diverticulitis occurs in approximately 13-20% of symptomatic cases 4
• Acute bleeding is less common in adults than children 5
• Perforation can occur but is relatively uncommon (10% of symptomatic cases) 4

Pathological Features

• Ectopic tissue is present in approximately 50-60% of cases 4
  • Gastric mucosa is most common (present in all cases with ectopic tissue in one study) 5
  • Pancreatic tissue can also be present, sometimes alongside gastric mucosa 5, 4
• Rare complications include malignant transformation (e.g., carcinoid tumors) 5

Diagnosis

• Often discovered incidentally during surgery for other conditions (74.5% in one study) 5
• CT imaging may be helpful but is often nonspecific 6
• Meckel scan (technetium-99m pertechnetate scintigraphy) is the most specific diagnostic test 2
  • Particularly useful for detecting ectopic gastric mucosa
  • 90% accuracy in pediatric patients, less accurate in adults 2

Gender Distribution

• Males are more likely to be symptomatic than females
• In one study, 50% of males with Meckel's diverticulum were symptomatic compared to only 13% of females 5
• Male:female ratio in symptomatic pediatric patients is approximately 2.6:1 4

Management Considerations

• Symptomatic Meckel's diverticulum requires surgical resection 3
• Management of incidentally discovered diverticulum remains controversial:
  • Some recommend routine resection in patients under 40 years 3
  • Others advise against incidental removal, particularly in women, due to potential complications 5
  • Surgical complications can include wound infections and anastomotic leaks (8.5% morbidity in one study) 5

In summary, Meckel's diverticulum is a true diverticulum found in approximately 2% of the population, is usually asymptomatic, and when symptomatic, presents differently in children (primarily bleeding) versus adults (primarily obstruction and diverticulitis).