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.