HistoryA 30-year-old woman presents with abdominal pain. She has a history of ulcerative colitis and is status post total proctocolectomy.
1.What is the etiology of the diagnosis?
Mechanical obstruction 机械性梗阻
2.What is a possible presentation of patients who have this finding?
Liver failure 肝功能衰竭
3.The finding is related to the patient’s diagnosis of ulcerative colitis.
4.What is a potential treatment for symptomatic patients?
Distal pancreatectomy 胰腺末端切除术
Findings and Diagnosis
FindingsThe dorsal pancreatic duct (yellow arrow), draining the pancreatic body and tail, is seen to empty through the accessory papilla, without definite connection to the shorter ventral pancreatic duct (blue arrow). The common bile duct (red arrow) joins the ventral pancreatic duct just proximal to the major papilla.
Pancreas divisum (PD) is the most common congenital anatomic variant of the pancreas. It occurs when there is a failure of fusion of the embryologic ventral and dorsal pancreatic ducts. The embryologic dorsal bud develops into pancreatic body and tail, as well as the superior pancreatic head.It is drained by the dorsal pancreatic duct of Santorini. The embryologic ventral bud develops into the uncinate process and the inferior pancreatic head, and is drained by the ventral duct of Wirsung. When the dorsal and ventral buds fuse at 8 weeks of gestation, the two pancreatic ducts join and also fuse with the biliary ductal system and empty through the major papilla. In PD, the dorsal duct fails to fuse with the ventral duct and instead empties through the smaller accessory papilla.
Most cases of PD are asymptomatic and discovered incidentally on thin-section CT, MRCP, or ERCP performed for other reasons. CT and MRI may demonstrate separate dorsal and ventral pancreatic moieties separated by a fat cleft. T2-weighted MR images and MRCP easily depicts the ductal system and the lack of communication between the dorsal and ventral ducts. This may occasionally be seen on thin-section CT as well.
PD is associated with idiopathic pancreatitis. It was once thought that the smaller diameter minor papilla causes a relative obstruction, given the larger amount of pancreatic secretions from the longer dorsal duct. However, since most cases are asymptomatic, it is currently thought that recurrent pancreatitis associated with PD is secondary to a stenotic minor papilla. Patients with PD who present with pancreatitis can demonstrate typical imaging findings of pancreatic edema, peripancreatic inflammation, pseudocyst formation, and possible pancreatic necrosis. With recurrent, chronic pancreatitis, the pancreas may become atrophied and the dorsal duct may become dilated.
Recurrent pancreatitis secondary to PD may be treated by surgical sphincteroplasty or endoscopic sphincterotomy of the stenotic minor papilla. A secretin test may be administered to determine whether there is obstruction at the minor papilla. Dilation of the pancreatic duct greater than 2 mm following secretin administration, which increases pancreatic bicarbonate secretion, suggests obstruction at the minor papilla. Pancreatic ductal dilation may be visualized with ultrasound or MRCP. Patients with demonstrated obstruction are more likely to benefit from surgical or endoscopic intervention.