title: Extrapancreatic necrosis without pancreatic parenchymal necrosis: a separate entity in necrotising pancreatitis?
abstract: OBJECTIVE
  In the revised Atlanta classification of acute pancreatitis, the term necrotising pancreatitis also refers to patients with only extrapancreatic fat necrosis without pancreatic parenchymal necrosis (EXPN), as determined on contrast-enhanced CT (CECT). Patients with EXPN are thought to have a better clinical outcome, although robust data are lacking.
  
  
  METHODS
  A post hoc analysis was performed of a prospective multicentre database including 639 patients with necrotising pancreatitis on contrast-enhanced CT. All CECT scans were reviewed by a single radiologist blinded to the clinical outcome. Patients with EXPN were compared with patients with pancreatic parenchymal necrosis (with or without extrapancreatic necrosis). Outcomes were persistent organ failure, need for intervention and mortality. A predefined subgroup analysis was performed on patients who developed infected necrosis.
  
  
  RESULTS
  315 patients with EXPN were compared with 324 patients with pancreatic parenchymal necrosis. Patients with EXPN less often suffered from complications: persistent organ failure (21% vs 45%, p<0.001), persistent multiple organ failure (15% vs 36%, p<0.001), infected necrosis (16% vs 47%, p<0.001), intervention (18% vs 57%, p<0.001) and mortality (9% vs 20%, p<0.001). When infection of extrapancreatic necrosis developed, outcomes between groups were equal (mortality with infected necrosis: EXPN 28% vs pancreatic necrosis 18%, p=0.16).
  
  
  CONCLUSIONS
  EXPN causes fewer complications than pancreatic parenchymal necrosis. It should therefore be considered a separate entity in acute pancreatitis. Outcome in cases of infected necrosis is similar.
authors: Department of Surgery, University Medical Center Utrecht, Utrecht, The Netherlands.
authors: Olaf J
authors: OJ
authors: Bakker
authors: Hjalmar
authors: H
authors: van Santvoort
authors: Marc G H
authors: MG
authors: Besselink
authors: Marja A
authors: MA
authors: Boermeester
authors: Casper
authors: C
authors: van Eijck
authors: Kees
authors: K
authors: Dejong
authors: Harry
authors: H
authors: van Goor
authors: Sijbrand
authors: S
authors: Hofker
authors: Usama
authors: U
authors: Ahmed Ali
authors: Hein G
authors: HG
authors: Gooszen
authors: Thomas L
authors: TL
authors: Bollen
mesh_terms: D000273:Adipose Tissue / Q000000981:diagnostic imaging / Q000473:pathology; D000328:Adult; D000368:Aged; D016208:Databases, Factual; D005260:Female; D006801:Humans; D059413:Intraabdominal Infections / Q000209:etiology; D008297:Male; D008875:Middle Aged; D009102:Multiple Organ Failure / Q000209:etiology; D009336:Necrosis / Q000000981:diagnostic imaging; D010179:Pancreas / Q000000981:diagnostic imaging / Q000473:pathology*; D010195:Pancreatitis / Q000145:classification / Q000150:complications / Q000000981:diagnostic imaging*; D019283:Pancreatitis, Acute Necrotizing / Q000145:classification / Q000150:complications / Q000000981:diagnostic imaging; D011379:Prognosis; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed