An analysis of factors associated with increased fluoroscopy time or the need for complex techniques at IVC filter retrieval

Objectives: To evaluate factors associated with increased fluoroscopy time or the need for complex techniques at IVC filter retrieval.

Methods: This is a single-institution retrospective cohort study of 187 consecutive patients who underwent IVC filter retrieval. An analysis was performed on associations of patient factors with increased fluoroscopy time and/or the need for complex retrieval techniques. A complex retrieval was defined as one requiring more than standard sheath and snare technique.

Results: Access vein during filter placement was not associated with filter tilt at placement or removal (p = 0.61 and 0.48). Neither the direction of the hook nor its relationship to the tilt was associated with the need for complex retrieval or increased retrieval fluoroscopy time (p = 0.25, 0.23, p = 0.18, 0.23). Tilt angle at placement correlated with hook apposition at time of removal (p = 0.01). Hook apposition was associated with complex retrieval and increased fluoroscopy time (p < 0.01). Larger tilt angle at placement was not associated with complex retrieval (p = 0.22), but a larger angle at removal was (p < 0.01). Longer dwell time correlated with the need for complex retrieval (p = 0.02). Filter type, sex, and age were not associated with complex retrievals (p = 0.58, p = 0.90, p = 0.99).

Conclusion: Contrary to previous hypotheses and studies, access vein for filter placement did not affect filter tilting, and direction of filter hook-tilt relationship did not affect retrieval fluoroscopy time or the need for complex retrieval techniques. Increased filter placement angle was associated with a larger angle at removal and hook-wall apposition, both of which were associated with complex retrievals.

Key points: • Filter hook orientation did not correlate with retrieval complexity. • Filter insertion vein did not correlate with filter tilt. • Filter tilt and hook apposition to the caval wall at the time of retrieval correlated with retrieval procedure complexity.