Pancreas Divisum and Pancreatitis: Implications and Rationale for Treatment

Abstract

The pancreas develops during the 8th week of gestation when the dorsal pancreatic anlage emerges from the medial wall of the duodenum and the ventral pancreatic anlage emerges from the liver bud on the lateral side of the duodenum. As it enlarges, the dorsal pancreas extends medially across the mid-line anterior to the mesenteric vessels. Eventually, it gives rise to the tail, body, and cephalad portion of the head of the pancreas. The ventral pancreatic anlage extends from the bile duct and, as the stomach and duodenum enlarge, the bile duct and ventral pancreas rotate behind the duodenum to eventually lie along the medial wall of the duodenum. As a result of this rotation, the terminal bile duct is situated behind or within the dorsal pancreas and the ventral pancreas lies behind the mesenteric vessels. Eventually, the ventral pancreas develops into the uncinate process and caudal portion of the head of the pancreas. The ventral pancreas is drained by the duct of Wirsung which, along with the bile duct, enters the duodenum at the papilla of Vater. The dorsal pancreas, on the other hand, is drained by the duct of Santorini which enters the duodenum at the lesser papilla. When the dorsal and ventral pancreata fuse, the ductal systems usually communicate and, in most instances, drainage predominantly occurs via the papilla of Vater.