Filters
Filters are mainly used when the clots occur in deep veins. Sometimes, patients are unable to take medications to thin their blood because of incompetency of these drugs or certain reactions that they trigger. In this case, doctors recommend placing a filter into large veins in the leg (posterior and anterior tibial vein). These filters prevent clots from breaking loose and migrating to other parts of the body. these filters are also placed in other large veins such as inferior vena cava. It is usually advisable to remove these filters when the risk of the clot travelling to other parts of the body has reduced or if the patient can take anticoagulants.