Symptomatic Pancreas Divisum: Recurrent Acute Pancreatitis in a 23-Year-Old Man
ERCP is the gold standard for diagnosing pancreas divisum because of its ability to visualize the anomalous anatomy as well as contribute a therapeutic effect by relieving pain and slowing the progression to chronic pancreatitis through a sphincterotomy or stenting the papilla.9,13 Pancreas divisum may be confirmed via cannulation of the minor duodenal papilla and dorsal pancreatography; however, cannulation of the minor papilla in pancreas divisum carries the risk of severe pancreatitis.6,13 MRCP for pancreas divisum performed with secretin stimulation has been shown to yield a significant diagnostic advantage. One meta-analysis demonstrated that secretin stimulated MRCP (S-MRCP) yielded a much higher overall sensitivity, and diagnostic odds ratio when compared with MRCP.21
Evidence of pancreas divisum on MRCP can be demonstrated by the common bile duct and dorsal pancreatic duct draining through 2 different duodenal apertures; where the dorsal pancreatic duct will drain through the minor duodenal papilla with no communication with the common bile duct.2 Recent studies have used secretin-stimulated MRCP (S-MRCP) to improve the accuracy and image quality.12 S-MRCP is noninvasive, has good sensitivity and specificity for the evaluation of pancreas divisum, and is not associated with a risk of pancreatitis, unlike ERCP.13 S-MRCP is the first-line imaging modality in diagnosing pancreas divisum due to its sensitivity and safety profile. However, it is more difficult to detect pancreas divisum in the setting of chronic pancreatitis by secretin stimulation due to a poorer-than-average secretin response and the presence of stones or strictures in either the ventral or dorsal pancreatic ducts.21
Endoscopic ultrasonography (EUS) has been used in the diagnosis of pancreas divisum. Absence of the “stack sign,” which normally shows the common bile duct, pancreatic duct, and portal vein, has been suggested as criterion for diagnosing pancreas divisum.13 Studies comparing EUS and MRCP in diagnosing pancreas divisum have had mixed results.13 Some have shown that MRCP has higher sensitivity and specificity, while others have demonstrated the opposite. EUS is more of an operator-dependent imaging modality, and it may not be possible to identify the ventral and dorsal ducts in all patients.13 Objective EUS criteria optimized for diagnosis of pancreas divisum must be defined. Additional studies comparing EUS to other modalities such as MRCP and ERCP are important to determine the role of EUS in diagnosis and predicting therapy response.13 While a promising investigative method, EUS remains in its infancy for use in pancreas divisum.