Risk factors for walled-off necrosis associated with severe acute pancreatitis: a multicenter retrospective observational study.

BACKGROUND/PURPOSE This study aimed to identify the risk factors for walled-off necrosis (WON) associated with severe acute pancreatitis (SAP). METHODS This retrospective study was conducted in eight institutions in Japan between 2014 and 2017. We analyzed WON incidence, patient characteristics, and risk factors for WON in patients with SAP who were observed for >28 days. RESULTS Of 134 patients with SAP, WON occurred in 40 (29.9%). Male sex (p = 0.045), body mass index (BMI) ≥25 (p < 0.001), post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (p = 0.020), and disseminated intravascular coagulation (DIC) (p = 0.001) were more frequent in the WON group than in the non-WON group. On admission, the frequency of white blood cell counts ≥12,000/µl (p = 0.037) and hypoenhanced pancreatic lesion on computed tomography (p = 0.047) were significantly higher in the WON group. In multivariate analysis, BMI ≥25 (odds ratio [OR] 5.73, 95% confidence interval [CI] 1.95-16.8; p = 0.002), post-ERCP (OR 8.08, 95% CI 1.57-41.7; p = 0.013), and DIC (OR 3.52, 95% CI 1.20-10.4; p = 0.022) were independent risk factors for WON. CONCLUSIONS High BMI, post-ERCP pancreatitis, and DIC are risk factors for the development of WON associated with SAP.