Definition

An annular pancreas is a ring of pancreatic tissue that encircles the duodenum (the first part of the small intestine). Normally, the pancreas sits next to, but does not surround, the duodenum.

Causes, incidence, and risk factors

Annular pancreas is a congenital defect, which means it is present at birth. Symptoms occur when the ring of pancreas squeezes and narrows the small intestine so that food cannot pass easily or at all.

Newborns may have symptoms of complete blockage of the intestine. However, up to half of people with this condition do not have symptoms until adulthood. There are also cases that are not detected because the symptoms are mild.

Conditions that may be associated with annular pancreas include:

• Down syndrome
• Other congenital gastrointestinal problems
• Pancreatitis
• Excessive amniotic fluid during pregnancy (polyhydramnios)

Symptoms

Newborns may not tolerate feedings. They may spit up more than normal, not drink enough breast milk or formula, and cry.

Adult symptoms may include:

• Fullness after eating
• Nausea or vomiting

Signs and tests

Tests include:

• Abdominal ultrasound
• Abdominal x-ray
• CT scan
• Upper GI and small bowel series

Treatment

Surgical bypass of the blocked part of the duodenum is the usual treatment for this disorder.

Expectations (prognosis)

The outcome is usually good with surgery.

Complications

• Obstructive jaundice
• Pancreatitis (inflammation of the pancreas)
• Peptic ulcer
• Perforation (tearing a hole) of the intestine due to obstruction
• Peritonitis

Calling your health care provider

Call for an appointment with your health care provider if you or your child have any symptoms of annular pancreas.

References

Russo MA, Redel CA. Anatomy, histology, embryology, and developmental anomalies of the stomach and duodenum. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger & Fordtran's Gastrointestinal and Liver Disease. 8th ed. Philadelphia, Pa: Saunders Elsevier; 2006:chap 45.