Meckel Diverticulum is the most common congenital anomaly of the gastrointestinal tract. It occurs from failure of the vitelline or omphalomesenteric duct to obliterate by the sixth week of fetal development. It is a true diverticulum that contains all layers of the bowel wall and is located on the antimesenteric border of the ileum. Half contain heterotopic gastrointestinal mucosa, usually gastric. A “rule of two” covers common facts: The incidence is 2%; the male/female ratio is 2:1; patients typically present before the age of 2 years; location is 2 ft from the ileocecal valve; and the base is typically 2 in. in width and often contains two types of mucosa.
The vast majority of Meckel diverticula are asymptomatic.
Bleeding is the most common presenting symptom. It tends to be painless and episodic. The source is typically acid-secreting gastric mucosa in the diverticulum that causes a peptic ulcer of adjacent normal ileum.
Intestinal obstruction occurs due to volvulus of the small bowel around a fibrous band connecting the diverticulum to the anterior abdominal wall. Intussusception or incarcerated hernia (Littré hernia) is the second-most-common presentation.
Meckel diverticulitis occurs in 20% of symptomatic patients and is often mistaken for acute appendicitis. Intraluminal obstruction of the diverticulum leads to inflammation, edema, ischemia, necrosis, and perforation in a manner similar to appendicitis.
Differential diagnosis may include appendicitis, colonic diverticulitis, or Crohn disease.
Resection is indicated in the symptomatic patient. For patients who present with obstruction, simple diverticulectomy can be performed. Segmental resections should be performed for acute diverticulitis, a wide-based diverticulum, volvulus with necrotic bowel, or bleeding.
Incidental diverticulectomy during surgery for other abdominal pathology is not indicated. Lifelong morbidity associated with the presence of a Meckel diverticulum is extremely low.