Etiology and VTE risk factor distribution in patients with inferior vena cava thrombosis.

Introduction: Inferior vena cava (IVC) thrombosis is a rare event and data detailing the underlying etiology are scarce.

Materials And Methods: Therefore, we reviewed all available cases of IVC thrombosis consecutively registered in the MAISTHRO (MAin-ISar-THROmbosis) database and described the prevalence of VTE risk factors and other conditions contributing to IVC thrombosis development.

Results: 53 patients (35 F, 18 M) with IVC thrombosis aged 12 to 79 years were identified. 40 patients (75.5%) developed thrombosis under the age of 45. Local problems, such as IVC anomalies or external venous compression, contributed to the development of thrombosis in 12 cases (22.6%). Lupus anticoagulants (10.9 vs. 2.3%, p=0.013) and malignoma (17.0 vs. 6.4%, p=0.023) were more prevalent in IVC thrombosis patients compared to 265 age and sex matched controls with isolated lower extremity DVT. No difference was identified with regard to inherited thrombophilia or other known VTE risk factors. Symptomatic pulmonary embolism (PE) occurred in 32.1% of IVC thrombosis patients compared to 15.2% of controls (p=0.005).

Conclusions: Local problems such as IVC anomalies and external venous compression, malignancy and the presence of lupus anticoagulants contribute to the risk of IVC thrombosis. The risk of symptomatic pulmonary embolism in the acute setting is high.