Venous Thromboembolism in Acute Necrotizing Pancreatitis Is Associated With Worse Outcomes, With Subtype-Specific Patterns: A Nationwide Analysis, 2016-2022

Objectives: Venous thromboembolism (VTE) complicates acute necrotizing pancreatitis (ANP), but outcomes across extra-splanchnic deep vein thrombosis (DVT), portal vein thrombosis (PVT), and splenic vein thrombosis (SVT) remain poorly defined. We evaluated national trends and in-hospital outcomes in ANP with versus without VTE and across VTE subtypes. Methods: Using the National Inpatient Sample (2016-2022), adults hospitalized with principal ANP were identified. Secondary diagnosis codes captured VTE subtypes. Primary analyses compared mortality and major complications in ANP with versus without VTE; secondary analyses compared outcomes by subtype. Results: Among 110,225 ANP hospitalizations, 12.25% had VTE. ANP with VTE had higher in-hospital mortality (aOR 1.89, P <0.001), longer length of stay (adjusted mean difference 10.7 d, P <0.001), and higher hospitalization charges (adjusted mean difference $151,685, P <0.001). VTE was associated with higher rates of mesenteric ischemia, gastric varices, upper GI bleeding, AKI, sepsis, shock, respiratory failure, ARDS, vasopressor use, mechanical ventilation, blood transfusion, and ICU admissions. On subtype analysis, DVT (aOR 2.39, P <0.001) and PVT (aOR 1.45, P =0.001) were associated with higher mortality; SVT was not significantly associated with mortality, though the analysis was limited by few events. PVT was most strongly associated with mesenteric ischemia (aOR 8.28, P <0.001), whereas gastric varices were most associated with SVT (aOR 11.37, P <0.001) and PVT (aOR 3.73, P <0.001). Conclusions: VTE in ANP was associated with higher in-hospital mortality, systemic complications, and resource utilization, with substantial heterogeneity across subtypes. DVT-associated ANP showed higher rates of systemic complications, whereas PVT and SVT showed distinct territory-specific vascular-complication patterns. Prospective studies should evaluate phenotype-specific anticoagulation strategies.