Thrombo-embolic venous diseases are represented by deep venous thrombosis and/or pulmonary embolism. In some patients with repeated thrombosis or occurrence of thrombosis in unusual sites, the etiological workup remains negative, which represents a problem for the management of the anticoagulant treatments. Recently, two factors have been identified as important in the physiopathology of hemostasis and coagulation: the presence of clonal hematopoiesis of indetermined potential (CHIP) and the formation of neutrophil extracellular traps (NETs). In this study, these two factors will be studied in patients with repeated venous thrombosis or thrombosis occurring in unusual site.