Diagnostic Accuracy of Pre-procedure MRI/MRCP in Patients Undergoing ERCP With Minor Papilla Cannulation in the Detection of Pancreas Divisum

Abstract

Introduction: Pancreas Divisum (PD) is the most common congenital anatomic abnormality of the pancreas, affecting 5-10% of the US population. PD is often asymptomatic, however, pancreatitis is presumed to develop due to decreased flow across a stenotic minor papilla. Endoscopic retrograde cholangiopancreatography (ERCP) is the gold standard diagnostic modality for PD, however, it carries the risk for potential complications. The purpose of this study was to evaluate the diagnostic yield of magnetic resonance imaging/magnetic resonance cholangiopancreatography (MRI/MRCP) in detecting PD. Methods: This was a single center retrospective analysis of patients in our tertiary referral center who underwent ERCP with diagnostic confirmation of PD between April 2009 and November 2016. Patient demographics, pre-procedural MRCP, and clinical co-variates were examined, and their impact on diagnosis was evaluated with univariate analysis. Results: In this cohort, 82 patients with PD underwent 173 ERCPs. Complete data from the initial ERCP and pre-procedural MRCP was available for 79 (96%) patients. None of the MRCPs were secretinenhanced. MRCP identified PD in 50 patients (63%) and did not identify PD in 29 (37%). Females were more likely than males to have PD diagnosed on MRCP (OR 3.33, CI 1.26-8.78, p=0.013). Age, race, history of smoking, alcohol use, and opioid use were not significantly different between groups (p=0.85, p=0.08, p=0.44, p=0.11, and p=0.99, respectively). Anatomic factors including presence of a native papilla, complete versus partial PD, presence of an IPMN, Santorinicele, annular pancreas, or anomalous pancreatobiliary junction were also similar between the two groups (p=0.81, p=0.14, p=0.62, p=1.00, p=1.00, and p=0.53 respectively). Additionally, neither a history of prior pancreatitis nor a history of pancreatic stent exchange (p =0.07 and p=0.19) were correlated with absence of a diagnosis of PD on MRCP. Conclusion: Pancreas divisum may not be detected by pre-procedure non-secretin enhanced MRI/MRCP in over one third of patients undergoing ERCP with minor papilla cannulation. The presence of other pancreatic anatomic variants, as well as prior manipulation or inflammation of the pancreas, did not appear to impact the diagnostic yield.