By the 4th week of gestation, ventral (caudal) and dorsal (cranial) outpouchings develop at the junction of the foregut and midgut. The gallbladder, extrahepatic bile ducts (EBDs), central intrahepatic bile ducts (IBDs), and ventralpancreas with its ductal network are derived from the ventral outpouching, the hepatic diverticulum. The dorsal bud is the precursor of the dorsal pancreas and its ductal system. At about this time, the developing ventral pancreas, gallbladder, and bile duct rotate clockwise posterior to the duodenum and join the dorsal pancreas in the retroperitoneum. The ventral pancreatic duct and the CBD are, therefore, linked by their embryologic origins, resulting in the adult configuration of their common entrance into the duodenum at the major duodenal papilla. At approximately the 7th gestational week, the dorsal and ventral pancreatic ducts fuse in the region of the neck. The territory drained by each system can vary, but in general the dorsal pancreatic ductal system drains the tail, body, and anterior portion of the pancreatic head, whereas the ventral component drains the posterior aspect of the pancreatic head. Both dorsal and ventral ducts variably drain the uncinate process of the pancreatic head. The portion of the ventral duct between the dorsal-ventral fusion point and the major papilla is termed the duct of Wirsung. The portion of the dorsal duct proximal to the dorsal-ventral fusion point is called the main pancreatic duct (MPD); if a segment of the dorsal duct persists distal to the dorsal-ventral fusion point, it is termed the duct of Santorini, or accessory duct.

Pancreas divisum is the most common congenital anomaly of the pancreatic ductal system, being reported in 4%–10% of the population. This anomaly results when the ventral and dorsal pancreatic ducts fail to fuse. The ventral duct (duct of Wirsung) drains only the ventral pancreatic anlage, whereas the majority of the gland empties into the minor papilla through the dorsal duct (duct of Santorini).

Focal dilatation of the terminal portion of the dorsal pancreatic duct, a condition known as santorinicele, is described in association with pancreas divisum and relative obstruction at the minor papilla.

Pancreas divisum is usually asymptomatic but is more frequently seen in patients with chronic abdominal pain and idiopathic pancreatitis than in the general population. 

MR pancreatography is useful in diagnosing congenital anomalies of the pancreatic duct without the risk of inducing pancreatitis. Recent technical advances have resulted in improved spatial resolution that permits visualization of ducts as small as 1 mm in diameter. Multi–detector row CT may also depict pancreas divisum, but only when the pancreatic duct is visualized. MR pancreatography has been shown to be highly sensitive and specific for pancreasdivisum. MR pancreatography demonstrates noncommunicating dorsal and ventral ducts, independent drainage sites, and a dominant dorsal pancreatic duct. The ventral duct is typically short and very narrow. Its branching patternmay be treelike, or the duct may be normal appearing but markedly diminished in size. At times, the ventral duct may be highly atretic. The dorsal duct is typically larger in caliber.