EUS and endoscopic pancreatic function tests (ePFTs) may be used to diagnose minimal-change chronic pancreatitis (MCCP). The impact of evaluation for exocrine pancreatic insufficiency (EPI) and real-time assessment of EUS changes after intravenous secretin on the clinical diagnosis of MCCP is unknown.

Patients with suspected MCCP underwent baseline EUS assessment of the pancreatic parenchyma and measurement of the main pancreatic duct (B-MPD) in the head, body, and tail. Human secretin 0.2 μg/kg was given intravenously followed 4, 8, and 12 minutes later by repeat MPD (S-MPD) measurements. Duodenal samples at 15, 30, and 45 minutes were aspirated to assess bicarbonate concentration. Endoscopists rated the percentage clinical likelihood of chronic pancreatitis (1) before secretin; (2) after secretin but before aspiration; and (3) after bicarbonate results.

A total of 145 consecutive patients (mean age, 44±13 years; 98 females) were diagnosed with EPI (n = 32; 22%) or normal exocrine pancreatic function (n = 131, 78%). S-MPD/B-MPD ratios in the tail 4 and 8 minutes after secretin were higher in the group with normal exocrine function. Ratios at other times, locations, and duodenal fluid volumes were similar between the 2 groups. A statistically significant change in the median percentage likelihood of chronic pancreatitis was noted after secretin in all groups. The sensitivity and specificity of EPI for the EUS diagnosis of chronic pancreatitis (≥5 criteria) were 23.4% (95% confidence interval, 12.3-38.0) and 78.6% (95% confidence interval, 69.1-86.2), respectively.

Real-time EUS findings and ePFTs have a significant impact on the clinical assessment of MCCP. The diagnosis of EPI shows poor correlation with the EUS diagnosis of MCCP. (Clinical trial registration number: NCT01997476.)