Evaluating approaches to diagnosis and management of idiopathic acute pancreatitis.

Introduction: Idiopathic acute pancreatitis (IAP) is a diagnosis of exclusion; systematic work-up is challenging but essential. Recent advances suggest IAP results from micro-choledocholithiasis, and that laparoscopic cholecystectomy (LC) or endoscopic sphincterotomy (ES) may prevent recurrence.

Methods: Patients diagnosed with IAP from 2015-21 were identified from discharge billing records. Acute pancreatitis was defined by the 2012 Atlanta classification. Complete workup was defined per Dutch and Japanese guidelines.

Results: A total of 1499 patients were diagnosed with IAP; 455 screened positive for pancreatitis. Most (N = 256, 56.2%) were screened for hypertriglyceridemia, 182 (40.0%) for IgG-4, and 18 (4.0%) MRCP or EUS, leaving 434 (29.0%) patients with potentially idiopathic pancreatitis. Only 61 (14.0%) received LC and 16 (3.7%) ES. Overall, 40% (N = 172) had recurrent pancreatitis versus 46% (N = 28/61) following LC and 19% (N = 3/16) following ES. Forty-three percent had stones on pathology after LC; none developed recurrence.

Conclusion: Complete workup for IAP is necessary but was performed in <5% of cases. Patients who potentially had IAP and received LC were definitively treated 60% of the time. The high rate of stones on pathology further supports empiric LC in this population. A systematic approach to IAP is lacking. Interventions aimed at biliary-lithiasis to prevent recurrent IAP have merit.