Gastrointestinal Radiology

GI Radiology > Pancreas > Congenital > Divisum

Pancreas Divisum

Pancreas divisum represents an anomaly of the fusion of the two pancreatic buds and their respective ducts. It is the most common pancreatic ductal system anomaly; it is seen in 4-6% of ERCP patients. The duct of ventral bud does not fuse with the duct system of the dorsal pancreatic bud; it joins the common bile duct at the level of the ampulla of Vater. The dorsal duct of pancreas, which drains the anterior head, body and tail, terminates more cephalad, at the minor duodenal papilla. The narrow size of the os in the minor papilla may result in inefficient drainage of pancreatic secretions. It is widely believed that pancreas divisum predisposes to chronic pancreatitis.

Embryological Development of the Pancreas

Friedman AC: The pancreas. In Taveras & Ferrucci, Radiology, Diagnosis-Imaging-Intervention. Phila: Lippincott-Raven, 1992, p 2.

C. Pancreas divisum
D. Normal fusion of the pancreatic buds and ducts

Schematic Representation of Normal and Divisum Ductal System

Gay, SB. "Radiology Recall" Lippincott Williams & Wilkins 2000, p394.

ERCP is the best modality for making the diagnosis of pancreas divisum. ERCP findings are described below. Endoscopic interventions have yeilded encouraging results for the treatment of pancreas divisum with acute recurrent pancreatitis. These interventions include endoscopic sphincterotomy of the minor ampulla with or without sphincterotomy of the major ampulla, ductal balloon dilatation, and pancreatic duct stent placement.

ERCP Findings in Pancreas Divisum
	Cannulation of the major duodenal papilla and injection of contrast material reveals only a short segment of the main pancreatic duct that arborizes within the head of pancreas, and does not opacify the main pancreatic duct in the pancreatic body and tail. A stent inserted previously through the minor papilla indicates the location of the dorsal pancreatic duct.
	Cannulation of the minor duodenal papilla and opacification of the dorsal pancreatic duct shows changes of chronic pancreatitis (alternating dilation and strictures producing a beaded apprearence).

Although the demonstration of ductal anatomy by CT is very difficult, the use of thin slices and appropriate algorithms can often show the pancreatic duct for most of its course. CT diagnosis of pancreas divisum is the based on the failure to see the union of the dorsal and ventral ducts. Additional CT signs of pancreatitis may be present in the dorsal duct distribution.

MRCP can also be used to image the pancreatic duct. The study can be repeated after secretin injection, and may demonstrate a functional obstruction of the pancreatic duct via the minor os.