Optional Inferior Vena Cava Filter Retrieval with Retained Thrombus: An in Vitro Model

Removing infrarenal inferior vena cava filters (IVCFs) with thrombus under protection of suprarenal IVCFs: A retrospective study in a single-center institution

To determine feasibility of removing inferior vena cava filters (IVCFs) with massive thrombus (>1*1cm) under protection of suprarenal IVCFs, and evaluate the filter thrombus detachment due to removal. The patients who had massive infrarenal IVCFs thrombus and received retrieval under protection of suprarenal IVCFs were retrospectively reviewed from July 2018 to December 2021. Medical data of them including demographics, filter types, dwell time, management, thrombus detachment was collected, and analyzed. There were 33 patients having massive infrarenal IVCFs thrombus and receiving retrieval under protection of suprarenal IVCFs including 23 males and 10 females with a mean age of 55.30 ± 11.97 (range, 30-85 years). All Infrarenal IVCFs were removed successfully and 29 cases (87.88%) were confirmed detachment of thrombus by cavography including 7 small-size thrombus (<1*1cm) and 22 large-size thrombus (>1*1cm). Twenty-two suprarenal IVCFs trapped large-size thrombus were treated with additional anticoagulation and 21 of them had successful retrievals with additional anticoagulation period of 66.18 ± 43.38 days (range, 9-154 days). The large-size IVCFs thrombus may be break off during retrieval, and IVCFs with large-size thrombus could be removed safely with suprarenal IVCFs protection. The thrombus trapped in filters could be reduced with an additional period of anticoagulation.

Comparison of the in vitro clot-capturing efficiencies of commercially available retrievable inferior vena cava filters

OBJECTIVE

We compared the in vitro clot-capturing efficiencies (CCEs) of commercially available retrievable inferior vena cava (IVC) filters.

METHODS

Four types of commercially available retrievable IVC filters were included in the present study: Denali (BD, Franklin Lakes, NJ), OptEase (Cordis Corp, Hialeah, Fla), Celect (Cook Medical, Bloomington, Ind), and Option (Argon Medical Devices, Frisco, Tex). The CCE of each IVC filter for 10 different size clots, ranging from 2 mm × 10 mm to 6 mm × 20 mm, was analyzed using a venous flow simulator.

RESULTS

When ≥4 × 10-mm clots were used, the CCEs were 100% for all four types of IVC filters in a 20-mm-diameter simulated IVC filter. However, when ≤3 × 20-mm clots were used, the CCEs were significantly different among the four types of filters in a 20-mm-diameter simulated IVC, with the Denali showing the highest CCE, followed by the OptEase, Celect, and Option. When ≥6 × 10-mm clots were used, the CCEs were 100% for all four types of IVC filters in the 25-mm-diameter simulated IVC. However, when ≤5 × 20-mm clots were used, the CCEs were significantly different among the four types of filters in the 25-mm-diameter simulated IVC, with the Denali showing the highest CCE. When ≤5 × 10-mm clots were used, the CCEs were significantly lower in the 25-mm-diameter simulated IVC than in the 20-mm-diameter simulated IVC for all four types of IVC filters, with Option showing the greatest change in CCEs, followed by the Celect, OptEase, and Denali.

CONCLUSIONS

The CCEs were significantly different among the four IVC filters and were significantly lower for the smaller size clots than for the larger size clots and for the larger diameter simulated IVC than for the smaller diameter simulated IVC.

Estimation of Trapped Thrombus Volumes in Retrievable Inferior Vena Cava Filters: A Visual Scale

PURPOSE

To establish a visual, objective scale for estimating trapped thrombus volumes in five types of retrievable inferior vena cava filters.

MATERIAL AND METHODS

Silicone-based radiopaque polymer volumes of 0.25, 0.5, 1.0, 1.5, 2.0, 3.0, and 4.0 mL were created. Both sphere and cone shapes were used. Polymer volumes were confirmed by means of the water displacement method. The volumes were then positioned to simulate trapped thrombus in five retrievable filters: Recovery and G2 (Bard Peripheral Vascular, Tempe, Ariz), Günther Tulip and Celect (Cook, Bloomington, Ind), and OptEase (Cordis Endovascular, Warren, NJ). Radiographs were obtained by using conventional parameters. Visual scales of thrombus volume were created for each filter type.

RESULTS

Visual scales for each retrievable filter type were created with simulated thrombi in typical trapping positions.

CONCLUSION

The authors developed a visual, objective scale for estimating trapped thrombus volume in five types of retrievable IVC filters. This could facilitate standardized reporting of thrombus volumes in studies of optional vena cava filters.