Prospective assessment of the ability of endoscopic ultrasound to diagnose, exclude, or establish the severity of chronic pancreatitis found by endoscopic retrograde cholangiopancreatography

Background: Our aim was to verify endoscopic ultrasound (EUS) accuracy to diagnose, rule out, and establish the severity of chronic pancreatitis found by endoscopic retrograde cholangiopancreatography (ERCP). Methods: Patients undergoing ERCP for unexplained abdominal pain and/or suspected chronic pancreatitis underwent EUS. EUS was performed by experienced operators who were aware of the history but blinded to ERCP results. Chronic pancreatitis was defined using the Cambridge classification: 0 to 1 = 'normal,' 2 to 4 = 'all chronic pancreatitis.' 3 to 4 = 'moderate to severe chronic pancreatitis.'The number of EUS criteria required to obtain sensitivity, specificity, positive and negative predictive values ≤ 85% was determined. EUS criteria for chronic pancreatitis are hyperechoic foci, hyperechoic strands, lobularity, hyperechoic duct, irregular duct, visible sidebranches, ductal dilation, calcification, and cysts. Results: One hundred twenty-six patients underwent EUS and ERCP. EUS was highly sensitive and specific (> 85%) depending on the number of criteria present. Chronic pancreatitis is likely (PPV > 85%) when more than two criteria (for 'all chronic pancreatitis') and more than six criteria (for 'moderate to severe chronic pancreatitis') are present. 'Moderate to severe chronic pancreatitis' is unlikely (NPV > 85%) when fewer than three criteria are present. Independent predictors of chronic pancreatitis were 'calcification' (p = 0.000001), history of alcohol abuse (p = 0.002), and the total number of EUS criteria (p = 0.008). Conclusions: EUS can accurately diagnose, rule out, and establish the severity of chronic pancreatitis found by ERCP.