Objective:To preliminarily explore the zoning of inflammatory lesions in patients with acute necrotizing pancreatitis (ANP) based on the peripancreatic membrane anatomy, and its impact on treatment outcome of ANP.Methods:Clinical data of 197 patients with ANP treated at Hunan Provincial People's Hospital from January 2021 to June 2022 were retrospectively analyzed, including 133 males and 64 females, aged (47.2±13.3) years old. Basic information, characteristics of pancreatitis, and imaging data were collected. The inflammatory lesions were partitioned based on the peripancreatic membrane anatomy. Patients were followed-up via outpatient visits or telephone reviews. According to the prognosis, patients were divided into the poor-prognosis group ( n=93), including patients with postoperative multi-organ failure, severe local complications, and death; and the non-poor-prognosis group ( n=104), including patients without these adverse outcomes. Multivariate logistic regression analysis was used to identify factors influencing prognosis. Receiver operating characteristic (ROC) curves were plotted to assess the predictive power of the number of involved regions for poor prognosis. Results:The inflammatory lesions of pancreas were divided into 13 regions: the lesser sac, pancreatic head and duodenum, left anterior renal, right anterior renal, left posterior renal, right posterior renal, left perirenal fat sac, right perirenal fat sac, left lateral abdominal wall, right lateral abdominal wall, left pelvic wall, right pelvic wall, and other regions. Significant differences were observed between the poor-prognosis group and the non-poor-prognosis group in terms of body mass index (BMI), pancreatic necrosis area, and the number of inflammatory lesion regions (all P<0.05). Multivariate logistic regression analysis showed that high BMI ( OR=1.723, 95% CI: 1.457-2.038, P<0.001), pancreatic necrosis area ≥50% ( OR=3.221, 95% CI: 1.073-9.668, P=0.037), and a higher number of inflammatory lesion regions ( OR=1.388, 95% CI: 1.110-1.735, P=0.004) were associated with a higher risk of poor prognosis in patients with ANP. Based on the number of inflammatory lesion regions, the ROC curve analysis revealed that the optimal cut-off value was 5.5 for predicting poor prognosis in patients with ANP, with an area under the curve of 0.747(95% CI: 0.680-0.815) and a sensitivity and specificity of 0.387 and 0.962, respectively. Conclusion:The peripancreatic membrane anatomy facilitates a relatively fixed partitioning of inflammatory lesions in patients with acute necrotizing pancreatitis, and the number of inflammatory lesion regions is associated with poor prognosis.