EUS in exploring the etiology of mild acute biliary pancreatitis with a negative finding of biliary origin by conventional radiological methods

BACKGROUND AND AIM: Conventional radiological methods, including transcutaneous ultrasonography (US), computed tomography (CT), and magnetic resonance cholangiopancreatography (MRCP) are non-invasive and recommended for the detection of etiologies of acute biliary pancreatitis (ABP). There are still, however, a number of patients whose etiologies cannot be found by these methods. The value of endoscopic ultrasound (EUS) for this population is still unknown. The aim of the present study was to evaluate the role of EUS in exploring the unknown etiology of mild ABP. METHODS: The data from patients with mild ABP admitted to Changhai Hospital, Shanghai, China, from June 2006 to December 2009 were retrospectively collected, and the results of the imaging methods in detecting biliary disorders were analyzed. RESULTS: A total of 223 patients with mild ABP underwent both US and CT. Of these, 106 underwent additional MRCP. There were still 37 patients with unknown biliary etiologies, even after the use of the conventional methods mentioned earlier. EUS was conducted in 33 of these patients. Abnormalities associated with the etiology of mild ABP were found in 14 cases (42.4%) confirmed by subsequent endoscopic retrograde cholangiopancreatography, with biliary stones in 11 cases, biliary sludge in two cases, and ampullary adenocarcinoma in one case. CONCLUSION: The results suggest that EUS is helpful in the identification of the etiology of mild biliary pancreatitis when conventional radiological imaging is negative or equivocal.