Annular pancreas
An annular pancreas is a ring of pancreatic tissue that encircles the duodenum (the first part of the small intestine). The normal position of the pancreas is next to, but not surrounding the duodenum.
The esophagus, stomach, large and small intestine, aided by the liver, gallbladder and pancreas convert the nutritive components of food into energy and break down the non-nutritive components into waste to be excreted.
Endocrine glands release hormones (chemical messengers) into the bloodstream to be transported to various organs and tissues throughout the body. For instance, the pancreas secretes insulin, which allows the body to regulate levels of sugar in the blood. The thyroid gets instructions from the pituitary to secrete hormones which determine the rate of metabolism in the body (the more hormone in the bloodstream, the faster the chemical activity; the less hormone, the slower the activity).
Annular pancreas is an abnormal ring or collar of pancreatic tissue that encircles the duodenum (the part of the small intestine that connects to stomach). This portion of pancreas can constrict the duodenum and block or impair the flow of food to the rest of the intestines. Symptoms from annular pancreas are nausea, vomiting, feeling of fullness after eating, and feeding problems in newborns. Surgical bypass of the obstructing segment of the duodenum is the usual treatment for this disorder.
Causes
Annular pancreas is problem present at birth (congenital defect). 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 one 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
- Excess amniotic fluid during pregnancy (polyhydramnios)
- Other congenital gastrointestinal problems
- Pancreatitis
Symptoms
Newborns may not feed well. 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
Exams and Tests
Tests include:
Abdominal ultrasound Abdominal x-ray - CT scan
Upper GI and small bowel series
Treatment
Treatment most often involves surgery to bypass the blocked part of the duodenum.
Outlook (Prognosis)
The outcome is most often good with surgery. Adults with an annular pancreas are at increased risk for pancreatic or biliary tract cancer.
Possible Complications
Complications may include:
- Obstructive jaundice
- Pancreatic cancer
- Pancreatitis (inflammation of the pancreas)
- Peptic ulcer
- Perforation (tearing a hole) of the intestine due to obstruction
- Peritonitis
When to Contact a Medical Professional
Contact your health care provider if you or your child has any symptoms of annular pancreas.
References
Maqbool A, Bales C, Liacouras CA. Intestinal atresia, stenosis, and malrotation. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 356.
Mehta MS, Barth BA, Husain SZ. Anatomy, histology, embryology, and developmental anomalies of the pancreas. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran's Gastrointestinal and Liver Disease: Pathophysiology/Diagnosis/Management. 11th ed. Philadelphia, PA: Elsevier; 2021:chap 55.
Semrin MG. Anatomy, histology, and developmental anomalies of the stomach and duodenum. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran's Gastrointestinal and Liver Disease: Pathophysiology/Diagnosis/Management. 11th ed. Philadelphia, PA: Elsevier; 2021:chap 49.
Version Info
Last reviewed on: 10/26/2021
Reviewed by: Michael M. Phillips, MD, Emeritus Professor of Medicine, The George Washington University School of Medicine, Washington, DC. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
