Impact of the site of necrosis on outcome of acute pancreatitis

OBJECIVES: To compare the clinical outcome of patients with extrapancreatic necrosis (EXPN) alone with that of acute interstitial pancreatitis (AIP), pancreatic parenchymal necrosis (PPN) alone, and combined PPN and EXPN. BACKGROUND: There are only a few studies in the literature in which EXPN has been recently recognized as a subtype of acute necrotizing pancreatitis (ANP), with a better prognosis. METHODS: We analyzed clinical data and outcome variables of 411 consecutive acute pancreatitis (AP) patients between January 2012 and December 2014. Contrast‐enhanced computed tomography (CECT) images of each patient were reviewed and characterized as AIP or ANP. Patients with ANP were divided into EXPN alone, PPN alone, and combined PPN and EXPN. Outcome variables were then compared between these groups. RESULTS: Of the 411 patients, 74 (18%) had AIP, and 337 (82%) had ANP. Patients with EXPN alone (n = 40; 11.8%) had similar outcomes as patients with PPN alone (n = 12; 3.5%); however, their outcome was worse than that of patients with AIP, with a higher frequency of persistent organ failure (POF), need for percutaneous catheter drainage (PCD), and longer length of hospitalization (LOH). Patients with combined PPN and EXPN (n = 285; 84.7%) had the worst clinical course, with higher frequency of POF, infected necrosis, intervention requirement, and longer LOH. CONCLUSION: Patients with combined PPN and EXPN have a severe disease course with the worst clinical outcomes; patients with AIP patients have the most benign course, while patients with EXPN alone stand between the two extremes of disease course with an intermediate grade of severity.