FILTERING THE EVIDENCE: UPDATES ON IVC FILTERS (Invited Lecture)
Benhood Bikdeli, M.D., 1. Dept of Medicine, Columbia University Medical Center, New York, NY, USA
2. Center for Outcomes Research and Evaluation (CORE), Yale School of Medicine, New Haven, CT, USA
3. Cardiovascular Research Foundation (CRF), New York, NY, USA
Pulmonary embolism (PE) is a serious form of venous thromboembolism (VTE), associated with significant risk of mortality, as well as short-term and long-term non-fatal sequelae. Although anticoagulation is the mainstay of treatment of VTE and prevention of subsequent events, the idea of interrupting the flow from lower extremity veins to help prevent a PE has been discussed in the literature for over a century. Initially attempted with ligation of the inferior vena cava (IVC), vena caval interruption is currently performed by use of IVC filters. Available for use since 1970ís with the premise of preventing subsequent PE, utilization rates of IVC filters dramatically increased between 1990ís and early 2000ís; in part influenced by the availability of retrievable filters and permissive recommendations from some scientific societies. Despite the initial enthusiasm, however, evidence to indicate the efficacy of these devices has been very slim. The two largest available randomized trials failed to show a reduction in PE-related mortality or all-cause mortality and recent pooled analyses do not confirm a net benefit in all-comers. Safety concerns -including those related to perforation, neighboring organ injury, fracture, and embolization of the IVC filter or its parts -have recently received further attention by investigators and regulatory agencies including the Food and Drug Administration. Adequately powered prospective controlled studies are required to determine the efficacy of IVC filters, in addition to large prospective studies to ascertain the safety profile of various types of IVC filters. Until then, indiscriminate use of this device should be minimized.