In vitro evaluation of a retrievable low-profile nitinol vena cava filter.

PURPOSE To evaluate the clot-trapping ability, stability, and migration of a new low-profile, retrievable inferior vena cava (IVC) filter in an in-vitro model. MATERIALS AND METHODS The SafeFlo IVC filter consists of two superelastic nitinol wires that form a double-ring platform and spiral filter. The filter is collapsed into a 5-6-F catheter and delivered into the IVC model. The in-vitro model closely simulates the physical parameters of flow in the human IVC. Human blood clots of 2-mm and 4-mm diameters and 3-cm lengths were injected into the flow system in sets of five clots. Filter delivery and retrieval were performed in every series. Filtration was evaluated in IVC models of 20-mm and 24-mm lumen diameter in vertical and horizontal positions. Stability and migration of the filter were evaluated by direct vision of maintenance of position and shape before and after clot trapping. RESULTS Filter delivery and retrieval were straightforward and repeatable in a total of 20 procedures. The filters maintained shape and position throughout the study. A total of 248 clots were injected and 225 (90.7%) were trapped. The individual tests in horizontal and vertical positions with either clot size demonstrated trapping rates of 85.7%-97.1%. CONCLUSIONS The SafeFlo IVC filter is a stable and effective filter in an in-vitro model. The filter design is amenable to simple delivery and retrieval.

[1]  M. Delichatsios,et al.  Inferior vena cava filters: in vitro comparison of clot trapping and flow dynamics. , 1988, Radiology.

[2]  B. Ransil,et al.  Comparative evaluation of clinically available inferior vena cava filters with an in vitro physiologic simulation of the vena cava. , 1993, Radiology.

[3]  A. Roberts,et al.  IVC filter tilt and asymmetry: comparison of the over-the-wire stainless-steel and titanium Greenfield IVC filters. , 1997, Journal of vascular and interventional radiology : JVIR.

[4]  A. Dibié,et al.  In Vivo Evaluation of a Retrievable Vena Cava Filter—The Dibie-Musset Filter: Experimental Results , 1998, CardioVascular and Interventional Radiology.

[5]  F. Barral,et al.  A clinical trial of vena caval filters in the prevention of pulmonary embolism in patients with proximal deep-vein thrombosis. Prévention du Risque d'Embolie Pulmonaire par Interruption Cave Study Group. , 1998, The New England journal of medicine.

[6]  T. Osler,et al.  Five-year follow-up of prophylactic vena cava filters in high-risk trauma patients. , 1998, Archives of surgery.

[7]  C. Walker,et al.  MR imaging of hyaline cartilage-containing tumors , 1998 .

[8]  S. Millward,et al.  Temporary and retrievable inferior vena cava filters: current status. , 1998, Journal of vascular and interventional radiology : JVIR.

[9]  M. Streiff Vena caval filters: a comprehensive review. , 2000, Blood.

[10]  L. Greenfield,et al.  Current Status of Inferior Vena Cava Filters , 2000, Annals of vascular surgery.

[11]  A. Roberts,et al.  Quality improvement guidelines for percutaneous permanent inferior vena cava filter placement for the prevention of pulmonary embolism. , 2001, Journal of vascular and interventional radiology : JVIR.