S2715 The Clot Thickens: A Descriptive Analysis of Splanchnic Vein Thrombosis Patients

Introduction: Splanchnic vein thrombosis (SVT) is associated with substantial short- and long-term mortality. Limited national data exist on the characteristics and outcomes of patients diagnosed with SVT. This study aims to enhance our understanding of the population that develops SVT and their outcomes. Methods: This retrospective chart review identified patients with confirmed SVT on CT reports from 2008 to 2023 at a single urban quaternary care center. Data collected included demographic variables, thrombus location, cirrhosis status, presence of intra-abdominal malignancy, and time of hospice referral or death. Chi-square and univariate logistic analyses were used to identify clinically relevant associations. Results: This study identified 1,184 patients with SVT confirmed on imaging. The median observation period was 64.6 months. Most patients were man (59.3%), and the mean age at SVT diagnosis was 57.8 years (SD = 14.5). The majority of patients had portal vein thrombi (88.2%). Hepatic vein thrombi (Budd-Chiari syndrome) were identified in 6.7% of patients, the majority of whom were women. Cirrhosis was documented in 40.9% of patients, malignancy in 31.9%, while 41.9% had neither cirrhosis nor malignancy. Women were more likely to have SVT with neither cirrhosis nor malignancy compared to men (48.3% vs 37.4%, P < 0.001). Those with cirrhosis were more likely to present with thrombi in the portal vein (OR = 3.50, CI: 2.22-5.51), splenic vein (OR = 0.47, CI: 0.35-0.63), and mesenteric vein (OR = 0.71, CI: 0.54 - 0.92) than those without cirrhosis. Those with malignancy were more likely to present with thrombi in the hepatic vein (OR = 2.33, CI: 1.39-3.93) and less likely in the splenic vein (OR = 0.47, CI: 0.35-0.63) and mesenteric veins (OR = 0.71, CI: 0.54-0.92) than those without. Risk of death/hospice was significantly higher for patients with cirrhosis (HR = 1.81, CI: 1.52-2.17) or malignancy (HR = 5.20, CI: 4.32-6.25) compared to patients without these conditions. Conclusion: This study is the largest U.S.-based analysis in the past decade characterizing patients with SVT. Our data show that among patients with SVT, those with cirrhosis and/or intra-abdominal malignancy have a different anatomic distribution of SVT and ultimately have a higher risk of mortality. The presence and location of SVT were also associated with sex. Improving our understanding of risk factors for and location of SVT can guide surveillance and assist with providing expectant management within this high-risk population.