Mechanical antithrombotic prophylaxis 335 postthrombotic syndrome treatment costs, vastly outweigh the costs of antithrombotic prophylaxis. Based on research studies and observational data, the widely available methods of prophylaxis are highly effective, also in terms of the costs. 3 The majority of hospitalized patients are burdened with at least 1 risk factor for VTE. The risk factors include age of more than 40 years, obesity (body mass index >30 kg/m 2), positive family history of VTE, multiorgan trauma, stroke, paresis or paraplegia, long-term immobilization, cancer, previous VTE, congenital or acquired thrombophilia, sepsis, New York Heart Association (NYHA) functional class III or IV, respiratory failure, autoimmune diseases, nephrotic syndrome, myeloproliferative disease, nocturnal paroxysmal hemoglobinuria, external venous compression (eg, tumor, hematoma, and arterial malformation), pregnancy and puerperium, long-term immobilization associated with travel (eg, long-distance flight), varicose veins in the lower limbs, obesity, and acute infection. 1,3 The risk factors related to diagnostic and therapeutic interventions are surgical procedures (especially major surgery in the lower limbs, pelvis, and abdomen), catheter placement in large veins, anticancer treatment (chemotherapy), hormonal treatment, use of angiogenesis inhibitors, use of oral contraceptives,