S2 Novel Mesenteric-Based Imaging Classification Predicts Oral Feeding Intolerance in Acute Pancreatitis

Introduction: Oral feeding intolerance (OFI) delays recovery and discharge in acute pancreatitis (AP). Timely resumption of an oral diet is recommended to preserve gut barrier integrity, limit the need for artificial nutrition, and shorten the length of stay. However, early predictors remain underexplored, and the ability to predict OFI during the admission remains elusive. We hypothesized that mesenteric inflammatory changes seen on the admission computed tomography (CT) could predict OFI. Methods: Adult AP patients admitted between 2019 to 2023 were identified from a prospective database. Exclusions were absence of a contrast-enhanced CT 3–7 days from pain onset or initial care outside our system. Patients were placed in 2 groups based on whether they had OFI, defined as requiring enteral nutrition or total parenteral nutrition. Two abdominal radiologists, blinded to outcomes, graded the level of mesenteric inflammation: Type 0 – none; Type 1 – changes involving the mesenteric root with vascular engorgement and focal fat stranding; Type 2 – diffuse mesenteric fat stranding without mass effect; Type 3 – diffuse mesenteric fat stranding with mass effect. Baseline demographic, clinical, and radiologic variables were compared between the groups. Univariable and multivariable analysis was completed to identify independent predictors of OFI. A P < 0.05 was considered significant. Results: Of 285 included patients (median age 44 [33-57] y; 62% men), 32 (11.2%) developed OFI. The incidence of OFI correlated with increasing mesenteric grade (Cochran-Armitage trend, P < 0.001). On multivariable analysis, severe mesenteric changes (Type 2/3) independently predicted OFI (adjusted odds ratio 6.21; 95% confidence interval 1.88–20.50; P = 0.0027), even after adjustment for disease severity, comorbidities, and other traditional covariates. Conclusion: Severity of mesenteric inflammation on the index CT is a strong, independent predictor of OFI in AP. Integrating a simple 4-tier mesenteric grading into routine imaging reports could flag high-risk patients on admission, prompting timely nutritional support and potentially improving patient outcomes by shortening hospital stay.