Does idiopathic acute pancreatitis really exist? Results of long-term follow-up after ERCP/EST

An aetiological association is identified in most patients with recurrent pancreatitis, by history and conventional diagnostic procedures. However, in 9% to 39% of cases no abnormalities are found and these patients are classified as having "idiopathic" recurrent pancreatitis. Between 1992 and 1995, 40 consecutive subjects with recurrent "idiopathic" pancreatitis (17 men and 23 women; mean age 54.8 years, range 25-82), with 2-7 (median 3) episodes over a 24-month period, underwent ERCP or biliary sphincterotomy (EST). After the endoscopic procedure, the patients were prospectively followed-up over a period ranging from 6 to 48 months (median, 29 months), and subdivided in different groups according to the aetiological factors detected by ERCP: A) 11 subjects with microlithiasis of the common bile duct, undergone EST; B) 11 subjects with suspected sphincter of Oddi dysfunction (type 3), of which 8 undergone EST and 3 treated with UDCA; C) 8 subjects with non-calculous gallbladder disease (biliary sludge, microlithiasis, parietal enlargement, dyskinesia): all undergone EST and laparoscopic cholecystectomy; D) 2 subjects with pancreas divisum (EST in one); E) 8 subjects without evidence of lesions, treated with UDCA alone. During the first 6 months of follow-up, 6 patients had still recurrent pancreatitis. Two cases with EST in group A underwent pancreatic EST, while 1 patient without previous EST in group A together with 2 cases in group A were treated with biliary EST. The remaining case had pancreas divisum. Then, acute pancreatitis still relapsed in 4 patients; 2 of them underwent pancreatic EST with symptom disappearance for at least 12 months. In conclusion, our long-term follow-up shows that diagnostic and therapeutic ERCP can detect the aetiology in almost all patients with "idiopathic" relapsing pancreatitis and cures 95% of them.