Changing Trends In Inferior Vena Cava Filter Indication For Venous Thromboembolism Over The Last Two Decades: A Retrospective Observational Study

Background: The present study aimed to evaluate changes in the incidence, patients' profile and indications of inferior vena cava filters at a single center over the past two decades.Methods: We retrospectively analyzed 187 consecutive patients with a venous thromboembolism requiring a filter at a tertiary hospital between 1999-2018. Within this period the availability of retrievable filters (since 2007) and the withdrawal of filter indication for recurrent venous thromboembolism from guidelines (since 2008) may have contributed to change practice patterns. Patients' profile, filter indication and survival were compared between decades (1999-2008 vs. 2009-2018).Results: The filter insertion rate doubled (60 vs. 127 cases) over 2009-2018. In this later period there was an unexpected rise (15 vs. 68 cases, P<0.001) of patients with isolated pulmonary embolism as baseline venous thromboembolism episode, without other relevant changes in patients' profile or survival. Regarding indications, there was an increase in filters for bleeding risk (23 vs. 45) and a reduction for venous thromboembolism recurrence (20 vs. 7), but also an unexpected increase of cases for bleeding (15 vs. 72). Among the 116 retrievable filters indicated for a temporary cause, 70 (60.3%) were finally not removed, being persistence of filter indication (n=33, 47.1%) the most common cause.Conclusions: The number of filters inserted at our institution has raised over the last two decades. This increase was partly unexpected and perhaps related to the availability of retrievable filters. Unfortunately these devices remain frequently non-removed being persistence of the indication the most frequent cause.