What is Meckel's diverticulum?

Meckel's Diverticulum: Definition, Presentation, and Management

Meckel's diverticulum is the most common congenital anomaly of the gastrointestinal tract, occurring in 2-3% of the population, resulting from incomplete obliteration of the omphalomesenteric duct during the seventh week of gestation.

Anatomy and Pathophysiology

Meckel's diverticulum is a true diverticulum containing all layers of the intestinal wall, appearing as a saccular, blind-ending structure located on the antimesenteric border of the distal ileum 1. Key characteristics include:

• Typically located approximately 60 cm proximal to the ileocecal valve 2
• Contains all layers of the intestinal wall
• Often contains heterotopic tissue:
  • Gastric tissue (60-85% of cases)
  • Pancreatic tissue (5-16% of cases) 3

Clinical Presentation

Most Meckel's diverticula remain asymptomatic throughout life. However, when symptomatic, they present with various complications:

1. Gastrointestinal bleeding - Most common presentation in children

   • Often painless and caused by peptic ulceration from acid secretion by ectopic gastric mucosa
   • Presents as melena or hematochezia 4

2. Intestinal obstruction - Can occur due to:

   • Internal hernia formation
   • Intussusception (with Meckel's as the lead point)
   • Volvulus or axial torsion 2, 4

3. Diverticulitis - Clinically mimics appendicitis with:

   • Right lower quadrant pain
   • Nausea and vomiting
   • Fever 4, 3

4. Perforation - Can lead to peritonitis 5

5. Rarely, neoplasms can develop within the diverticulum 5

Diagnosis

The diagnosis of Meckel's diverticulum can be challenging due to its nonspecific presentation. Key diagnostic approaches include:

• Technetium-99m pertechnetate scan (Meckel scan) - Most useful diagnostic method

  • Works by detecting uptake of the isotope in heterotopic gastric mucosa
  • Particularly useful in children and young adults with unexplained GI bleeding 6, 3
  • Should be considered when other tests for GI bleeding are negative 6

• CT enterography (CTE) - May identify Meckel's diverticulum but has limited sensitivity 6

• Video capsule endoscopy - Can sometimes identify Meckel's diverticulum when other tests are negative 6

• Surgical exploration - Often the definitive diagnostic approach, especially in cases with acute presentation 2

Management

The management of Meckel's diverticulum is primarily surgical:

• Symptomatic Meckel's diverticulum: Surgical resection is indicated for all symptomatic cases

  • Resection of the diverticulum and surrounding ileum with end-to-end anastomosis 2

• Incidentally discovered Meckel's diverticulum: Management remains somewhat controversial, but resection is often performed to prevent future complications, especially if risk factors are present:

  • Diverticulum length >2 cm
  • Narrow base
  • Presence of heterotopic tissue
  • Fibrous bands connecting to the umbilicus or mesentery 2

Special Considerations

• Bleeding: In young patients with recurrent or unexplained lower GI bleeding, Meckel's diverticulum should always be considered in the differential diagnosis 6

• Iron deficiency anemia: Meckel's diverticulum is listed as an uncommon cause of occult GI blood loss leading to iron deficiency anemia 6

• Small bowel obstruction: In patients with virgin abdomen (no prior surgery) presenting with small bowel obstruction, Meckel's diverticulum should be considered as a potential cause 6

Complications of Surgical Management

Surgical management of Meckel's diverticulum is generally safe with low complication rates. In pediatric populations, studies have shown no significant complications or mortality following surgical resection 4.