A New Entity of Walled off Extra Pancreatic Necrosis is Associated with Better Outcomes Following Endoscopic Transmural Drainage

Background & Aims: Previous studies have shown that patients with extra-pancreatic necrosis (EPN) alone are associated with better outcomes than patients with pancreatic necrosis (PN) in acute pancreatitis (AP). The natural history and drainage outcome of pancreatic collections resulting from PN vs. EPN has not been studied. Methods: Clinical records of a prospectively maintained cohort of AP patients who underwent endoscopic drainage of walled of necrosis (WON) were reviewed. Computed tomography (CT) done on day 4 to 7 of illness was reviewed to identify EPN alone (Group 1) or PN with or without EPN (Group 2). Group 1 and 2 were compared for WON characteristics, as well as outcome and adverse effects of endoscopic drainage. Results: Seventy-one patients in Group 2 (57 males; mean age 38.6 +/- 11.5 years) were compared with sixteen patients in Group 1 (12 males; mean age 34.5 +/- 10.8 years). WON developing in Group 2 were significantly larger (11.7 +/- 2.8 cm vs. 9.5 +/- 2.03 cm) with higher solid necrotic debris (30.4 +/- 9.8% vs. 13.7 +/- 7.2%). Endoscopic transmural drainage of WON associated with PN required a greater number of direct endoscopic necrosectomy (DEN) sessions along with a longer time for resolution. The time taken for resolution correlated with size (r=0.629, p <0.01) and solid debris content (r=0.647, p<0.01), which were significantly higher in the PN group. Conclusions: 'Ibis new entity of walled of extra pancreatic necrosis alone has lesser solid necrotic debris and its endoscopic drainage is associated with better outcomes as compared to patients with walled off pancreatic necrosis.