Understanding the problem

The first-choice treatment for venous thromboembolism is anticoagulants, which prevent blood clots from becoming larger or travelling from the leg to the lungs (PE) and new clots from forming (recurrent VTE). Because some people cannot take anticoagulants or are at high risk of developing a new or recurrent PE, IVCFs have been used for many years as an alternative treatment option or in addition to anticoagulants.

IVCFs are inserted through the skin at the groin or neck and placed into the largest vein of the pelvis, which carries blood from the lower body back to the heart. They have an umbrella-like form and allow blood to pass but are designed to catch medium- or large-sized blood clots. Unlike anticoagulants, IVCFs do not increase the risk of bleeding, and they can be used during surgery. Most of the filters used nowadays can be removed once they are no longer needed. However, complications can occur, such as insertion problems; broken filters (with pieces later travelling to other body parts), or blockage of the filter by blood clots. Also, the longer filters are left in place, the more likely they will become attached to the vein wall, making retrieval difficult or impossible.

Although IVCFs are widely used, particularly in the U.S., only a few studies have actually evaluated the benefits and risks of IVCF use compared to no filter use. Therefore, expert recommendations are not consistent.

The aim of this article was to report the results of a systematic review and meta-analysis that identified and combined published studies assessing the risks and benefits of IVCFs in people at risk of developing PE.