Clinical predictors for thrombus progression in cirrhotic patients with untreated splanchnic vein thrombosis

Introduction: Splanchnic vein thrombosis (SVT) occurs in a heterogenous group of patients secondary to a variety of risk factors including liver disease. Minimal data regarding natural history and outcomes of SVT exists to inform management decisions. As such, there is equipoise regarding the utility of anticoagulation in cirrhotic patients with SVT. We sought to identify clinical factors predictive of new or progressive thrombosis in a cohort of patients with untreated SVT. Methods: We conducted a retrospective cohort study of cirrhotic patients over 18 years of age diagnosed with SVT at the Oregon Health & Science University from 2015 to 2020, excluding those initially treated with anticoagulation. The primary study endpoint was a composite of the following: imaging-confirmed progression of SVT, development of cavernous transformation, intestinal ischemia, portal cholangiopathy or new venous or arterial thrombosis. Results: 261 patients were included in the analysis (median age 61 years, 68% male, 32% female). Forty percent of all patients experienced the primary composite endpoint. Multivariable logistic regression found that only the presence of pancreatitis or abdominal infection at diagnosis was associated with an increased likelihood of experiencing thrombus progression in patients with untreated SVT (OR 3.61, P = 0.02). There was a statistically significant overall survival difference between patients that did and did not experience the primary composite endpoint after controlling for confounding variables. (p = 0.0068). Conclusions: Overall, only the presence of pancreatitis or intrabdominal infection were found to be significantly associated with thrombotic progression, with varices identified as marginally non-significant risk factor. Notably, thrombotic progression was associated with a significant reduction in overall survival.