Endoscopic Ultrasonography for the diagnosis of Chronic Pancreatitis

Aims: EUS has been shown to be sensitive in the detection of morphologic abnormalities due to chronic pancreatitis (CP). Unfortunately there are uncertainties about the specificity of EUS findings, particularly in the early stages of CP. Since the “gold standard“ for the diagnosis of CP (tissue diagnosis) is lacking, one way to validate findings is to do a clinical follow-up.

Aim: To understand if in a clinical context suspect for CP, patients who have a normal ERCP but an EUS that shows features of CP, will develop imagilogic or clinical characteristic features of CP, confirming a higher sensitivity of EUS, or on the other hand, if they have false positive EUS for CP.

Method: A retrospective review of the EUS database from Jan 96– Dec 99, found 240 patients less than 65 years old and clinical symptoms suggestive of CP that had both EUS and ERCP. Of these 240 patients, 48 (20%) had discrepancy between EUS and ERCP findings, with normal ERCP but EUS features of moderate/high probability for CP (≥3 features). Chart review or contact by phone was used to document pancreatitis.

Results: 48 patients (Female 34; mean age 42 (range 19–62) were reviewed. Average follow-up was 8.4 years (range 7–9.6). 29/48 (60%) patients were contacted or chart reviewed, 19 lost to follow-up. Of those suspected of having early CP in which EUS was the only abnormality, 16/29 (55%) progressed clinically such that the diagnosis could be established. 13/29 (45%) did not have a diagnosis of pancreatitis on follow-up.

Conclusion: EUS can be used in the preliminary diagnosis of CP. Before 2001 we used ≥3 criteria on EUS to diagnose CP. We decided based on histology and a higher specificity rather than sensitivity to label patients as “CP“; we changed our criteria from ≥3 to ≥5. Thus, some of the 45% that did not evolve into clear CP may have been read as normal by today's criteria.