Meckel's Diverticulum

Meckel’s diverticulum is a common congenital condition characterized by the presence of a small pouch in the intestinal wall, at the junction where the small and large intestines meet.

The pouch is usually seen near the ileocecal valve and contains gastric and/or pancreatic tissue. The gastric tissue secretes hydrochloric acid that causes ulcers in the ileum. Thus it can become inflamed and obstruct the intestines, even bleeding occasionally with or without pain.

Meckel's diverticulum is seen in approximately 2-3% of the general population, though related symptoms are shown by only a fraction of these people. Some people do not exhibit any symptoms of Meckel's diverticulum all their lives.

This condition affects both males and females, though its complications are seen 2-3 times more often in males. Meckel's diverticulum is one of the most common birth defects found in the gastrointestinal tract.

Pathophysiology

Meckel’s diverticulum develops around the sixth week of fetal development. The vitelline duct which connects the terminal ileum to the umbilicus is usually wiped out during early fetal life.  When this does not happen, a diverticulum develops.

Thus, the sac is a remnant tissue resulting during the development of the fetal digestive system. The tissue is not the same as that found in the rest of the small intestine. It is another type of tissue usually found in the pancreas or stomach.

Roughly 50% of the sac contains heterotopic stomach or pancreas tissue, which can produce acid that irritates the sensitive intestinal lining and eventually cause an ulcer.

The rupture of this ulcer can result in intestinal waste leaking into the abdomen, which results in a serious infection known as peritonitis. This can block the intestine.

An ulcer in the intestine can result in significant bleeding which can cause anemia. High levels of blood loss can cause a child to go into a life-threatening shock.

Bleeding is more commonly seen in children younger than 5 years and occurs due to ulcers caused by acid secretion in the sac.

Obstruction of the intestine occurs at all ages but is more common among adults. It is usually a result of volvulus, adhesions, foreign bodies, or tumors. Acute Meckel’s diverticulitis can develop at any age, though it is more common in older children.

Diagnosis, Treatment, and Prognosis

Meckel’s diverticulum is very difficult to diagnose. The doctor gathers the child’s full medical history and studies it thoroughly.

A physical exam follows next, after which the doctor might order imaging tests to visualize the intestines. Other tests such as blood test and stool test are also used in the diagnosis of Meckel’s diverticulum.

Treatment of Meckel's diverticulum depends on several factors such the child’s age, health status, and medical history; the degree of complications; and the family’s preference.

Abdominal or laparoscopic surgery is usually performed to remove the diverticulum. Once a Meckel's diverticulum is successfully repaired, no long-term issues are usually seen. Thus, the prognosis is excellent for people with Meckel's diverticulum.

References

• http://www.stanfordchildrens.org/en/topic/default?id=meckels-diverticulum-90-P02010
• http://my.clevelandclinic.org/childrens-hospital/health-info/diseases-conditions/hic-meckels-diverticulum
• http://www.merckmanuals.com/professional/gastrointestinal-disorders/diverticular-disease/meckel-diverticulum