Purpose: Accurately detecting inferior vena cava (IVC) filter complications is important for safe and successful retrieval as tip-embedded filters require removal with non-standard techniques. Venography prior to IVC filter retrieval has traditionally used a single anterior-posterior (AP) projection. This study compares the utility of rotational venography to AP venography prior to IVC filter removal.
Materials and methods: The rotational venograms from 100 consecutive IVC filter retrievals over a 35-month period were evaluated retrospectively. The AP view of the rotational venogram was examined separately from the full series by a radiologist blinded to alternative imaging and operative findings. The venograms were evaluated for tip embedding, filter fracture, filter thrombus, and IVC thrombus. Statistical analysis was performed.
Results: Using operative findings and peri-procedural imaging as the reference standard, tip embedding occurred in 59 of the 100 filters (59%). AP venography was used to correctly identify 31 tip-embedded filters (53% sensitivity) with two false positives (95% specificity) for an accuracy of 70%. Rotational venography was used to correctly identify 58 tip-embedded filters (98% sensitivity) with one false positive (98% specificity) for an accuracy of 98%. A significant difference was found in the sensitivities of the two diagnostic approaches (P < .01). Other findings of thrombus and filter fracture were not significantly different between the two groups.
Conclusion: Rotational venograms allow for more accurate detection of tip-embedded IVC filters compared to AP views alone. As this determines the approach taken, rotational venograms are helpful if obtained prior to IVC filter retrieval.