A 67-year-old man with a history of hypertension presents with a swollen right lower extremity. An ultrasound reveals a DVT, and he is commenced on low-molecular-weight heparin and warfarin. Two days later, he develops slurred speech and right-sided weakness. A head CT reveals an intracranial hemorrhage. When should an inferior vena cava (IVC) filter be utilized for treatment of DVT?
It is estimated that 350,000 to 600,000 Americans develop a VTE each year.1 Patients with a DVT are at high risk of developing a pulmonary embolism (PE). In a multicenter study, nearly 40% of patients admitted with a DVT had evidence of a PE on ventilation perfusion scan.2 Treatment of a DVT is aimed at preventing the extension of the DVT and embolization.3 The American College of Chest Physicians (ACCP) recommends anticoagulation as the primary DVT treatment (Grade 1A).4 However, IVC filters might be considered when anticoagulation is contraindicated.
In 1868, Trousseau created the conceptual model of surgical interruption of the IVC to prevent PE. However, it wasn’t until 1959 by Bottini that the surgical interruption was successfully performed.5 The Mobin-Uddin filter was introduced in 1967 as the first mechanical IVC filter.6 IVC filters mechanically trap the DVT, preventing emboli from traveling into the pulmonary vasculature.7
There are two classes of IVC filters: permanent filters and removable filters. Removable filters include both temporary filters and retrievable filters. Temporary filters are attached to a catheter that exits the skin and therefore must be removed due to the risk of infection and embolization.7 Retrievable filters are similar in design to permanent filters but are designed to be removed. However, this must be done with caution, as neointimal hyperplasia can prevent removal or cause vessel wall damage upon removal.8
IVC filters are inserted into the vena cava percutaneously via the femoral or jugular approach under fluoroscopy or ultrasound guidance (see Figure 1, p. 16). The filters typically are placed infrarenally, unless there is an indication for a suprarenal filter (e.g., renal vein thrombosis or IVC thrombus extending above the renal veins).7 Complete IVC thrombosis is an absolute contraindication to IVC filter placement, and the relative contraindications include significant coagulopathy and bacteremia.9
The incidence of complications related to IVC filter placement is 4% to 11%. Complications include:
- Insertion-site thrombosis;
- IVC thrombosis;
- Recurrent DVT postphlebitic syndrome;
- Filter migration;
- Erosion of the filter through the vessel wall; and
- Vena caval obstruction.10
A review of the National Hospital Discharge Survey database for trends in IVC filter use in the U.S. found a dramatic increase in the use of IVC filters from 1979 to 1999—to 49,000 patients from 2,000 patients with IVC filters in place. The indications for IVC filter use vary such that it is imperative there are well-designed trials and guidelines to guide appropriate use.11