An annular pancreas is a congenital deformity in which part of the organ becomes wrapped around a section of the duodenum, the upper neck of the small intestine. If the pancreas completely obstructs the duodenum, the condition is noticeable shortly after birth as an infant is unable to feed. In most cases, however, the intestine is only partially obstructed, if at all, and an annular pancreas is not detected until some time in adulthood. The condition is usually treated with surgery to bypass the duodenum and connect the stomach to a lower section of the small intestine.
The pancreas is normally positioned adjacent to the duodenum, just underneath the stomach. Problems occur if the head of the pancreas forms a ring around the duodenum instead of resting against it. Infants who are born prematurely are at the highest risk of having the deformity, as the head and neck of the pancreas may never fully develop. It is common for a baby to have other defects as well, such as an underdeveloped esophagus or Down syndrome. An infant who has an annular pancreas may not be able to digest milk, causing him or her to spit up regularly.
If an annular pancreas does not completely encircle the duodenum, it may not cause noticeable symptoms in infancy. In fact, an annular pancreas often goes undiagnosed until it is discovered during a medical examination for another condition. If symptoms do arise in adulthood, they may include nausea, vomiting, food intolerance, and a constant feeling of fullness. Pancreatitis, inflammation and swelling of the pancreas, often triggers such symptoms in adults.
A doctor can diagnose an annular pancreas in an infant or an adult by performing a series of diagnostic imaging tests. Ultrasounds, x-rays, and computerized tomography scans are used to detect abnormalities and gauge the severity of duodenal obstruction. After making a diagnosis, the doctor can refer the patient to an internal medicine specialist to evaluate the need for surgery.
The most common surgical procedure to treat an annular pancreas is called a duodenoduodenostomy. During the procedure, a surgeon inserts a tiny camera into the abdominal cavity to inspect the stomach and small intestine. He or she makes a series of small incisions in the lower abdomen and manipulates surgical tools to sever the stomach from the duodenum, bypass the section constrained by the pancreas, and connect it to the next section of the intestine. The surgery has a high success rate, and most infants and adults recover completely in a few months.