Stratification of Pre-procedure Risk Factors Associated with Difficult-to-remove Inferior Vena Cava (IVC) Filters: A 6-year Retrospective Analysis at a Tertiary Center

Purpose: Currently, data surrounding predicting difficulty of IVC filter retrievals are heterogenous and conflicting. We aimed to identify which of many variables associated with IVC filters is a risk for procedural difficulty. Materials and Methods: This study retrospectively reviewed 6 years of IVC filter retrievals at a tertiary center identifying 356 consecutive retrievals. A difficult retrieval was defined as any case where the fluoroscopy time exceeded 7 min, an advanced technique was required, the retrieval attempt failed and required an additional attempt or was left permanent, or there was major complication such as IVC filter fracture/migration/vessel injury. Results: There were 105 filter retrievals defined as difficult (29.5%). Univariate analysis showed significantly increased risk for retrievals with an embedded top. Multivariate analysis assessed the association between dwell time, tilt, age, non-hooked filters, leg penetration and difficult retrieval. This showed a significant increase in the difficulty of retrieval for filters tilted between 5° and 15° (odds ratio 2.38, p < 0.001), for filters tilted more than 15° (odds ratio 7.91, p < 0.001), and dwell time greater than 6 months (odds ratio 2.06, p = 0.033). No significant increase in difficulty was seen with filters with a dwell time of less than 6 months, leg penetration, non-hooked filters, or with increasing patient age. Conclusions: Identifying these risks in patients in advance of the procedure allows appropriate planning and improved workflow efficiency.