Evaluation of Duct-Cell and Acinar-Cell Function and Endosonographic Abnormalities in Patients With Suspected Chronic Pancreatitis

Background & Aims: Endoscopic ultrasound (EUS) detects mild and severe structural abnormalities of the pancreas that correlate with fibrosis. Direct pancreatic function tests (PFTs) detect mild exocrine insufficiency associated with early fibrosis. The primary aim of this study was to compare EUS structural criteria with duct-cell and acinar-cell function. Methods: Fifty patients evaluated for chronic pancreatitis underwent combined EUS and secretin endoscopic PFTs (ePFT) on day 1 and CCK ePFT on day 2. EUS images were videotaped and interpreted by consensus of 3 blinded expert reviewers. Results: There were inverse correlations of EUS consensus score with both duct-cell bicarbonate secretion (R = -0.71, P < .001) and acinar-cell lipase secretion (R = -0.52, P < .001). With secretin ePFT as reference standard, EUS (≥4 criteria) showed a sensitivity of 71% (95% confidence interval [CI], 53%-89%) and specificity of 92% (95% CI, 75%-99%). With CCK ePFT as reference standard, EUS had a sensitivity of 63% (95% CI, 43%-82%) and specificity of 85% (95% CI, 71%-98%). Main duct dilation, irregularity, calcifications, and visible side-branches were most predictive of exocrine insufficiency (positive predictive value >80% for both acinar- and duct-cell insufficiency). Conclusions: Acinar- and duct-cell function decreases as EUS structural abnormalities increase. EUS has fair sensitivity and very good specificity compared with secretin and CCK functional reference standards.