Retrievable Filters: Maximizing Retrieval Rates

Abstract

c w f t t w t p t g r p a s f p c t The use of permanent inferior vena cava (IVC) filters is effective in the prevention or reduction of pulmonary embolism (PE) in patients with contraindications to anticoagulation or in patients who have failed anticoagulation.1-3 Risks of permanent filters are well known, including fracture, IVC penetration, symptomatic IVC thrombosis, and development of deep venous thrombosis (DVT).4 Retrievable filters llow for short-term filtration and thus avoid long-term comlications in patients who are only temporarily at risk for the evelopment of PE. The Gunther Tulip filter (GTF; Cook, nc, Bloomington, IN) was the first to be introduced in the arly 2000s in the United States. Since then, use of retrievable lters has increased, with relatively low complications and ood efficacy in the prevention of PE.5-9 However, their use has been hampered by slightly greater cost and lack of longterm follow-up compared with permanent filters. Although indications for filter use have expanded, there are authors who believe this in not supported by evidence.10 Several filters are approved for use (Fig. 1, Table 1). The design of retrievable filters is driven by the opposing duality of ease of long-term retrieval on the one hand and stability of the device against migration and penetration or perforation on the other. These 2 forces appear at times diametrically opposed as demonstrated by the performance of the GTF and the Recovery filter, 2 of the first filters approved for retrieval. The GTF has fewer issues with penetration and migration but because of significantly more wall contact of the secondary struts and resulting incorporation, it has lower retrieval rates after longer dwelling times of 6 months or more. The Recovery filter, by contrast, had issues with migration and yet seemed to have fewer problems with longterm retrieval.