Pancreas divisum

Pancreas divisum is a common congenital anomaly (an anomaly that is present at birth) of the pancreatic duct(s). The Pancreas is a deep-seated organ located behind the stomach. One of its functions is to produce enzymes that are important for the digestion of food in the intestine. The digestive enzymes, in the form of digestive juice, drain from the pancreas via the pancreatic duct into the duodenum (the upper portion of the small intestine) where they aid in digesting food.

The human embryo starts life with two ducts in the pancreas; the ventral duct and the dorsal duct. In more than 90% of the embryos, the dorsal and the ventral ducts will fuse to form one main pancreatic duct. The main pancreatic duct will join the common bile duct (the duct that drains bile from the gallbladder and the liver) to form a common bile and pancreatic duct which drains into the duodenum through the major papilla. In approximately 10% of embryos, the dorsal and the ventral ducts fail to fuse. Failure of the ventral and the dorsal pancreatic ducts to fuse is called pancreas divisum (because the pancreas is drained by two ducts). In pancreas divisum, the ventral duct drains into the major papilla, while the dorsal duct drains into a separate minor papilla.

The majority of individuals born with pancreas divisum experience no symptoms throughout life, will remain undiagnosed and will not require treatment. A small number of patients with pancreas divisum will experience repeated episodes of pancreatitis. Pancreatitis is an inflammation of the pancreas that can cause severe abdominal pain and more severe complications. Some patients with pancreas divisum may develop chronic abdominal pain without pancreatitis.

Doctors are not certain how pancreas divisum causes abdominal pain and pancreatitis. One theory is that the minor papilla is too narrow to adequately drain the digestive juices in the dorsal duct. The backup of the digestive juices elevates the pressure in the minor duct that causes abdominal pain and pancreatitis.

The most accurate test to diagnose pancreas divisum is ERCP, which can demonstrate the presence of two separately draining pancreatic ducts. However, ERCP itself sometimes can cause attacks of pancreatitis. Other tests that can help diagnose pancreas divisum without the risk of causing pancreatitis include endoscopic ultrasound (EUS), and MRI (magnetic resonance imaging).

Pancreas divisum without symptoms needs no treatment. Treatment of patients with abdominal pain and recurrent pancreatitis attributable to pancreas divisum has not been well established. Some doctors will attempt sphincterotomy (cutting of the minor papilla during ERCP to enlarge its opening). Others will insert a stent during ERCP into the duct to prevent duct blockage. These procedures are not risk free. Therefore, patients with symptomatic pancreas divisum are best evaluated and treated by doctors in centers experienced in treating pancreatic diseases.