Purpose: Although recommended placement of IVC filters is with their tips positioned at the level of the renal vein inflow, in practice, adherence is limited due to clinical situation or IVC anatomy. We seek to evaluate the indwelling and retrieval complications of IVC filters based on their specific position within the infrarenal IVC.
Materials and methods: Retrospective, single institution study of 333 consecutive infrarenal vena cava filters placed by interventional radiologists in patients with an average age of 62.2 ± 15.7 years was performed between 2013 and 2015. Primary indication was venous thromboembolic disease (n = 320, 96.1%). Filters were classified based on location of the apex below the lowest renal vein inflow on the procedural venogram: less than 1 cm (n = 180, 54.1%), 1-2 cm (n = 96, 28.8%), and greater than 2 cm (n = 57, 17.1%). Denali (n = 171, 51.4%) and Celect (n = 162, 48.6%) filters were evaluated. CT follow-up, indwelling complications, and retrieval data were obtained.
Results: Follow-up CT imaging performed for symptomatic indications occurred for 38.3% of filters placed < 1 cm below the lowest renal vein, 27.1% of filters placed 1-2 cm, and 36.8% placed > 2 cm (p = .16). There was no difference in caval strut penetration, penetration of adjacent viscera, time to penetration, filter migration, or tilt (p = .15, .27, .41, .57, .93). No filter fractures occurred. There was no difference in the incidence of breakthrough PE or complex filter retrieval (p = .83, .59). Only one retrieval failure occurred.
Conclusions: This study suggests filter apex location within the infrarenal IVC, including placement > 2 cm below the level of the renal vein inflow, is not associated with differences in indwelling or retrieval complications.
Level of evidence: Level 3 non-randomized controlled follow-up study.
Keywords: Inferior vena cava; Pulmonary embolism; Vena cava filter.