# Annular pancreas

Annular pancreas

This is the result of  failure of  complete rotation of  the ventral pancreatic bud during development, so that a ring of  pancre - atic tissue surrounds the second or third part of  the duodenum. It is most often seen in association with congenital duodenal stenosis or atresia and is therefore more prevalent in children with Down syndrome. Duodenal obstruction typically causes vomiting in the neonate (see Chapter 18 ). The usual treat - - ment is bypass (duodenoduodenostomy). The diagnosis  may be made in later life as a cause of  pancreatitis, in which case resection of  the head of  the pancreas should be considered.