Meckel’s diverticulum - Disorders of the small bowel and appendix

Meckel’s diverticulum

Definition

An ileal diverticulum occurring as a result of persistence of part of the vitellointestinal duct.

Incidence

2% of the population, the most common congenital abnormality of the GI tract.

Age

Congenital

Sex

2M > 1F

Aetiology

The vitellointestinal duct runs from the umbilicus to the ileum. By birth the duct has either disappeared or is normally only a small fibrous cord. Persistence of the duct may result in a Meckel’s diverticulum (persistence of the ileal end of the duct), an umbilical sinus (persistence of the umbilical end of the duct) or an umbilical ileal fistula (see Fig. 4.7).

Pathophysiology

The diverticulum arises from the antimesenteric border of the ileum 2 ft from the ileocaecal valve and is on average 2 inches long. Ten per cent of diverticula are joined to the umbilicus by a fibrous cord. Acid secreting gastric mucosa is found in 50% of cases which may result in ulceration of the surrounding mucosa.

Clinical features

Ninety-five per cent of cases are asymptomatic, symptomatic patients present most commonly with bleeding due to ulceration of the adjacent ileum. Intestinal obstruction may result from intussusception of the diverticulum or from a volvulus.

Investigations

Presence of gastric mucosa can be detected by scintiscanning with 99mTc labelled sodium pertechnetate, which is taken up by parietal cells (the Meckel’s scan).

Management

Symptomatic Meckel’s diverticula are excised by wedge resection.