The role of intraductal US in the management of idiopathic recurrent pancreatitis without a definite cause on ERCP

Background The cause of pancreatitis is unknown in as many as 30% of cases of recurrent acute pancreatitis, even after ERCP. Objective To investigate the role of intraductal US (IDUS) for managing idiopathic recurrent pancreatitis (IRP). Design Prospective study. Setting Tertiary referral hospital. Patients Thirty-one patients with suspicious IRP with negative findings on ERCP. Interventions IDUS during ERCP. Main Outcome Measurements IDUS findings showing any possible cause of pancreatitis. Results IDUS revealed small bile duct stones (≤3 mm) in 5 patients (16.1%) and sludge in 3 patients (9.7%). The detection rate for a bile duct stone and sludge was significantly higher in patients with a dilated CBD than a nondilated CBD on ERCP (71.4 vs 12.5%; P < .05). Recurrent pancreatitis did not develop in 7 of 8 patients with biliary stones or sludge after an endoscopic sphincterotomy (EST). Two patients (6.5%) demonstrated a small polypoid lesion on the distal end of the pancreatic duct. One patient underwent surgery for intra-ampullary cancer, and another one underwent EST without another attack of pancreatitis. Three patients (9.7%) showed evidence of chronic pancreatitis with small pancreatic stones and/or calcifications on IDUS. Limitations Small number of patients. IDUS results were not compared with those of conventional EUS. There was no reference standard for chronic pancreatitis as diagnosed by IDUS. Conclusions IDUS identified a possible cause of idiopathic recurrent pancreatitis in 42% of patients with negative findings on ERCP. The IDUS-guided approach combined with ERCP and EST may be useful for decreasing recurring attacks of pancreatitis.