Abstract
Deep vein thrombosis (DVT) is common in the general population, with an annual incidence of 1 to 2 per 1000 people. Inferior vena cava agenesis (IVCA) increased the risk of developing DVT and is found in approximately 5% of young adults (20-40-year-olds) diagnosed with unprovoked proximal DVT. IVCA can be caused by a defective embryological process, or be a result of intrauterine or perinatal thrombosis. Its estimated incidence in the general population ranges from 0.0005% to 1%, usually involving a partial absence of one of the four segments of the inferior vena cava (IVC). The management during the extended phase of patients with DVT associated with IVCA is not yet harmonized, as it is poorly described in the literature. Patients with IVCA are considered to be at high risk of DVT occurrence, prompting physicians to continue extended anticoagulation, often using vitamin K antagonists. In this retrospective study, we present a cohort of 11 patients diagnosed with IVCA following a DVT, who subsequently received extended treatment with a direct oral anticoagulants. These findings offer reassuring insights into the extended utilization of direct oral anticoagulants, demonstrating both antithrombotic efficacy and a favorable safety profile.