Endoscopic ultrasonography in the evaluation of idiopathic acute pancreatitis

Background: 'Idiopathic' pancreatitis may be diagnosed when gallstones are excluded by transabdominal ultrasonography and less common causes are not i mplicated by history or other investigations. Transabdominal ultrasonograph y may not, however, detect small stones responsible for acute pancreatitis. The aim of this study was to determine if endoscopic ultrasonography (EUS) is able to identify undetected gallstones in cases of 'idiopathic' pancrea titis. Methods: Consecutive patients presenting with 'idiopathic' pancreatitis wer e assessed using EUS for the presence of gallstones or other potential caus es of the attack. A control group was also imaged. Results: Forty-four patients with 'idiopathic' pancreatitis were assessed. Ten had suffered earlier attacks of pancreatitis before this study. EUS rev ealed proven pathology in 18 patients. Unconfirmed pathology was evident in 14. No abnormality was seen in only nine patients. EUS failed in one patie nt and there were two possible false-positive results. Conclusion: EUS is able to identify significant pathology in patients in wh om a diagnosis of 'idiopathic' pancreatitis has been made following standar d investigations. Patients with untreated gallstones are at risk of recurre nt attacks. Idiopathic pancreatitis should not be diagnosed unless EUS has been performed.