Meckel Diverticulum

The first description of a small bowel diverticulum was in 1598 by a German surgeon Wilhelm Hildanus.
Alexis Littre also noted a small bowel diverticulum, this time in an inguinal hernia in 1745.
Nevertheless, this entity was ultimately named after anatomist Johann Meckel in 1809 after he further described the anatomy and embryology of this unique structure.¹

RELEVANT ANATOMY

The Meckel diverticulum is a true diverticulum containing all layers of the intestinal wall (Figure 23.1).
- It is located on the antimesenteric border of the ileum.
- The “rule of 2’s” is a helpful way to remember the general anatomic features of a Meckel diverticulum.
- Meckel diverticulum is usually located within 2 feet of the ileocecal valve, approximately 2 inches in length, and contains 2 distinct types of heterotopic mucosa, gastric (the more common) and pancreatic (Figure 23.2).

EPIDEMIOLOGY AND ETIOLOGY

Meckel diverticulum is the most common congenital abnormality of the small intestine.
Approximately 2% of the population has a Meckel diverticulum, but only approximately 4% of patients with a Meckel diverticulum become symptomatic.¹
The risk of developing symptoms decreases with increasing age.
There does not appear to be a familial link.
Males are twice as likely as females to have a Meckel diverticulum.
It is noted that the prevalence is increased in children with malformations of the umbilicus, alimentary tract, nervous system, and cardiovascular system.²
A Meckel diverticulum is a remnant of the omphalomesenteric (vitelline) duct, which in the fetus connects the midgut to the yolk sac.
The omphalomesenteric duct usually involutes between the fifth to seventh weeks of gestation.
Failure of this involution can lead to a wide variety of pathologies, most commonly a Meckel diverticulum (Figure 23.3A).
Other anatomic varieties seen secondary to a persistent omphalomesenteric duct include omphalomesenteric cysts (Figure 23.3B), fistulae (Figure 23.3C), umbilical polyps, and persistent fibrous cords.
The blood supply to the Meckel diverticulum is from the vitelline artery off the superior mesenteric artery.¹

Figure 23.1 Meckel diverticulum seen on the antimesenteric border of the ileum. (Reprinted with permission from Agur AMR, Dalley AF. Grant’s Atlas of Anatomy. 14th ed. Philadelphia, PA: Wolters Kluwer; 2017.)

Figure 23.2 Ectopic gastric fundic and pancreatic tissue in the mucosa line the diverticulum, 100×. (Reprinted with permission from Husain AN, Stocker JT, Dehner LP. Stocker & Dehner’s Pediatric Pathology. 4th ed. Philadelphia, PA: Wolters Kluwer; 2016.)

Only gold members can continue reading. Log In or Register to continue