Branch Duct IPMN-Associated Acute Pancreatitis in a Large Single-Center Cohort Study

: Background/Objectives: IPMNs are a possible cause of acute pancreatitis (AP). IPMN-associated-AP is considered a relative indication for surgery for the prevention of recurrent attacks of pancreatitis and for a hypothesized increased cancer risk. The literature is based on surgical series, and no data on the clinical features of AP associated with IPMNs and on the risk of recurrent pancreatitis and pancreatic cancer are available. This study aimed to describe the clinical/radiological features of BD-IPMN-associated AP. Moreover, BD-IPMN-associated risk factors for AP recurrence and risk of pancreatic cancer were investigated. Methods: Patients with AP associated with branch-duct IPMN (BD-IPMN) without "worrisome- features" and "high-risk-stigmata" evaluated in a Gastroenterology Unit (University of Verona) between 1 January 2012 and 31 December 2022 were retrospectively analyzed. Cox proportional hazard models were used to analyze the time to recurrence after the first occurrence of AP. Results: One hundred and thirty-five patients were included, with a mean age of 55.8 ± 12.5 years. Necrosis was diagnosed in 15 patients (11.1%) and 1 patient (0.7%) was admitted to the ICU. One hundred and two (75.6%) patients had recurrent pancreatitis. The median size of the largest BD-IPMN was 8 mm (Q1-Q3: 5-12). Eighteen patients (13.3%) developed main pancreatic duct dilation ≥ 5 mm. No patients developed dilation of the main pancreatic duct ≥ 10 mm, mural nodules, thickened cystic walls, or jaundice. In the unadjusted analysis, no BD-IPMN-related features were associated with an increased risk of recurrent pancreatitis. None of the patients developed pancreatic cancer. Conclusions: BD-IPMN-associated AP appears to have a benign clinical course. Cystic features related to increased risk of recurrence were not identified. The risk of cancer appears extremely low.