annular pancreas

Annular pancreas is a congenital developmental malformation in which the fusion position of the two pancreatic buds is abnormal during the embryonic period. Also, when the duodenum rotates, the ventral pancreatic bud remains fixed and elongates, and when it later fuses with the dorsal pancreatic bud, it encircles the descending duodenum, compressing the duodenum and causing high intestinal obstruction, which is called annular pancreas. In fact, the head of the pancreas in annular pancreas still lies within the duodenal arc, and the tissue of the annular portion contains the same islets of Langerhans and acinar tissue as the normal pancreas. Annular pancreas is one of the causes of congenital duodenal obstruction in children. The pancreatic duct of the annular pancreas may enter the main pancreatic duct and then open into the duodenum, or open separately into the duodenal lumen. Annular pancreas is often accompanied by abnormal openings of the pancreatic and bile ducts and coexists with duodenal atresia or stenosis. Therefore, rashly performing separation and division or partial resection of the annular pancreas during surgery not only fails to relieve the obstruction but also leads to hemorrhage of pancreatic tissue, injury to the pancreas, bile duct, or duodenum, pancreatic fistula, bilioenteric fistula, etc.