Prospective evaluation of endoscopic ultrasonography, endoscopic retrograde pancreatography, and secretin test in the diagnosis of chronic pancreatitis.

BACKGROUND: Chronic pancreatitis in its early stages may defy diagnosis despite existing diagnostic modalities. Endoscopic retrograde pancreatography (ERCP), secretin test, and conventional ultrasound are insensitive in detecting the early stages of chronic pancreatitis. The aim of this study was to determine whether endoscopic ultrasonography (EUS) high-resolution imaging allows for the detection of chronic pancreatitis as compared with clinical history, ERCP, and secretin test.

METHODS: Eighty consecutive patients with recurrent pancreatitis underwent ERCP, EUS, and secretin test. EUS evaluated parenchymal changes: echogenic foci (calcification), prominent interlobular septae (fibrosis), small cystic cavities (edema), lobulated outer gland margin (fibrosis/atrophy), and heterogeneous parenchyma; and ductal changes: dilation, irregularity, echogenic wall (fibrosis), side-branch ectasia, and echogenic foci (stones). EUS criteria for chronic pancreatitis included mild (1 to 2 features), moderate (3 to 5 features), and severe (more than 5 features).

RESULTS: Abnormal studies were EUS = 63, ERCP = 36, and secretin test = 25. Secretin test had 100% agreement with normal and severe chronic pancreatitis by EUS criteria, but agreement was poor for mild (13%) and moderate (50%) disease. Alternatively, the agreement between ERCP- and EUS-specific criteria was excellent for normal (100%), moderate (92%), and severe (100%) chronic pancreatitis and poor for mild (17%) disease. When the 2-test modality (ERCP and secretin test) was compared with EUS alone, no enhancement in agreement was seen.

CONCLUSION: Using the above criteria EUS may assist in the diagnosis of chronic pancreatitis not established by ERCP or secretin test. Excellent agreement can be expected between EUS and ERCP in the diagnosis of chronic pancreatitis with the exception of mild changes noted on EUS (kappa statistics = 0.82: 95% CI [0.70, 0.95]). Long-term follow-up of the patients with mild EUS changes will determine the validity of EUS in diagnosing the early stages of chronic pancreatitis.