thrombosis prevention thrombosis prevention thrombosis prevention or thromboprophylaxis is medical treatment to prevent the development of thrombosis (blood clots inside blood vessels) in those considered at risk for developing thrombosis. some people are at a higher risk for the formation of blood clots than others, such as those with cancer undergoing a surgical procedure. prevention measures or interventions are usually begun after surgery as the associated immobility will increase a person's risk. this article is about preventing blood clots. for how blood clots form, see thrombosis. for information on blood clots in the legs, see deep vein thrombosis. thrombosis preventiona blood clot blocking a blood vessel.other namesthrombosis prophylaxisicd-10-pcsi80-i82icd-9-cm437.6, 453, 671.5, 671.9 blood thinners are used to prevent clots, these blood thinners have different effectiveness and safety profiles. a 2018 systematic review found 20 studies that included 9771 people with cancer. the evidence did not identify any difference between the effects of different blood thinners on death, developing a clot, or bleeding. a 2021 review found that low molecular weight heparin (lmwh) was superior to unfractionated heparin in the initial treatment of venous thromboembolism for people with cancer. there are medication-based interventions and non-medication-based interventions. the risk of developing blood clots can be lowered by life style modifications, the discontinuation of oral contraceptives, and weight loss. in those at high risk both interventions are often used. the treatments to prevent the formation of blood clots is balanced against the risk of bleeding. one of the goals of blood clot prevention is to limit venous stasis as this is a significant risk factor for forming blood clots in the deep veins of the legs. venous stasis can occur during the long periods of not moving. thrombosis prevention is also recommended during air travel. thrombosis prophylaxis is effective in preventing the formation of blood clots, their lodging in the veins, and their developing into thromboemboli that can travel through the circulatory system to cause blockage and subsequent tissue death in other organs. clarence crafoord is credited with the first use of thrombosis prophylaxis in the 1930s. pathophysiology of blood clot prevention the development of blood clots can be interrupted and prevented by the use of medication, changing risk factors and other interventions. some risk factors can be modified. these would be losing weight, increasing exercise and the cessation of oral contraceptives. moving during periods of travel is a modifiable behavior. preventing blood clots includes the use of medications that interrupt the complex clotting cascade and changing the proteins that are needed for clotting. antiplatelet drugs also have an effect in preventing the formation of clots. medical treatments thrombosis prophylaxis is not only used for the prevention of deep vein thrombosis, but can be initiated for the prevention of the formation of blood clots in other organs and circumstances unrelated to deep vein thrombosis: cerebral complications abortion ectopic pregnancy molar pregnancy pregnancy childbirth and the puerperium coronary portal vein thrombosis intracranial, nonpyogenic intraspinal, nonpyogenic mesenteric pulmonary epidemiology of developing blood clots the risk of developing deep vein thrombosis, or pulmonary embolism is different than the total risk of the formation of blood clots. this is due to the observation that not all blood clots form in the lower legs. most hospitalized medical patients have at least 1 risk factor for thrombosis that progresses to thromboembolism and this risk persists weeks after discharge. those who remain undiagnosed and not treated prophylactically have a 26% chance of developing a fatal embolism. another 26% develop another embolism. between 5% and 10% of all in hospital deaths are due to pulmonary embolism (as a consequence of thrombosis). estimates of the incidence of pulmonary embolism in the us is 0.1% persons/year. hospital admissions in the us for pulmonary embolism are 200,000 to 300,000 yearly. thrombosis that develops into dvt will affect 900,000 people and kill up to 100,000 in the us. on average 28,726 hospitalized adults aged 18 and older with a vte blood clot diagnosis die each year. risk of thrombosis is related to hospitalization. in 2005 the uk the parliamentary health select committee determined the annual rate of death due to thrombosis was 25,000 with at least 50% being hospital-acquired. the type of surgery performed prior to the formation of blood clots influences the risk. without prophylactic interventions, the calculated incidence of clot formation in the lower leg veins after surgery is: 22% for neurosurgery 26% for abdominal surgery 45% for 60% in orthopedic surgery 14% for gynecologic surgery as the population of the us ages, the development of blood clots is becoming more common. general risks and indications for blood clot prevention some risk factors for developing blood clots are considered higher that others. one scoring system analyzes the probability for clot formation by assigning a point value system to significant risk factors. the benefit of treating those who are at low risk of developing blood clots may not outweigh the higher risks of significant bleeding. risk factors for developing blood clots that are assessed prior to treatments risk factornotes