Objectives: To evaluate the diagnostic yield of endoscopic ultrasonography (EUS) in patients with idiopathic acute pancreatitis (IAP), find factors predictive of a positive EUS finding in these patients and investigate whether these etiological findings are maintained during follow-up.
Material and methods: We performed EUS in patients with IAP between July 2004 and August 2007. We recorded epidemiological data, the number and severity of previous bouts of pancreatitis and gallbladder status.
Results: A total of 44 patients were included in the study. EUS was normal in seven patients (16%). In the remaining 37 patients (84%) we found cholelithiasis (n = 3), microlithiasis (n = 20), chronic pancreatitis (n = 14), pancreas divisum (n = 3), pancreatic mass (n = 1), apudoma (n = 1), cystic tumor of the pancreas (n = 2) and choledocholithiasis (n = 2). Positive EUS findings were not influenced by sex, severity of pancreatitis or recurrent disease. Patients aged < 65 years (age > or < 65 years: 73.9% versus 95.2%; P = 0.097) and patients with gallbladder in situ (cholecystectomy versus non-cholecystectomy: 63.6% versus 90.9%; P = 0.054) showed a tendency to have positive EUS findings. Mean follow-up was 28.95 +/- 10.86 months (range 12-64 months; median 28 months). During follow-up the etiological diagnosis was changed in two patients, lowering the diagnostic yield to 79%.
Conclusions: EUS identified the cause of IAP in 79% of patients. Patients with gallbladder in situ and patients aged < 65 years showed a tendency to have positive EUS findings. The majority of the diagnoses provided by EUS are maintained during follow-up and seem to be reliable.