Postthrombotic syndrome in relation to vena cava filter placement: a systematic review.

The use of inferior vena cava (IVC) filters to prevent pulmonary embolism (PE) in patients who have or are at risk of developing deep vein thrombosis is increasing. A systematic review was performed to assess the frequency of symptoms and signs of postthrombotic syndrome (PTS) in relation to IVC filter placement. It was also assessed whether the initial indication for IVC filter placement-prevention of PE in a patient without known venous thrombosis (i.e., primary prevention) versus prevention of PE in patients with known venous thrombosis (i.e., secondary prevention)-or concurrent use of anticoagulation or compression stockings influenced this rate. Eleven articles describing 1,552 patients met criteria for review. At a mean follow-up of 4.5 years, the weighted pooled incidence of edema was 42.9% (95% CI, 40.4%-45.4%), and that of chronic skin changes (including venous ulcers) was 12.0% (95% CI, 10.3%-13.7%). Among patients who had IVC filter insertion for secondary prevention, 51.2% (95% CI, 48.3%, 54.1%) had edema and 13.5% (95% CI, 11.5%, 15.5%) had skin changes at follow-up, compared with 20.2% (95% CI, 15.7%, 24.7%) and 8.3% (95% CI, 5.2%-11.4%), respectively, in patients who received an IVC filter for primary prevention. One study reported no difference in the frequency of symptoms and signs of PTS according to whether anticoagulation was initiated in addition to filter placement. No study reported rates of PTS according to use of elastic compression stockings after filter placement. The present results raise the possibility that IVC filters could be associated with the development of PTS, including venous ulcers, when used for the primary or secondary prevention of PE. However, as a result of the important limitations of the articles reviewed, further research is required to directly address this issue.