The optional VenaTech(™) Convertible (™) vena cava filter: experimental study in sheep.

Area of Science:

• Vascular Surgery
• Interventional Radiology
• Biomedical Engineering

Background:

• Retrieval of optional inferior vena cava (IVC) filters can be challenging due to complications like tilting, migration, fracture, or embedding.
• A novel convertible IVC filter designed for easier retrieval by removing the filter head was developed.

Purpose of the Study:

• To evaluate the safety and feasibility of a new convertible IVC filter.
• To assess the performance of the VenaTech Convertible IVC filter in terms of implantation, conversion, and retrieval.

Main Methods:

• Forty-nine sheep underwent IVC catheterization and insertion of VenaTech Convertible IVC filters.
• Filters were either permanently placed or designated for conversion immediately or after 1, 3, or 6 months.
• Filter performance, including migration, tilting, and IVC wall incorporation, was assessed via cavography and gross anatomy.

Main Results:

• Successful delivery, deployment, and immediate conversion were achieved in all cases.
• Delayed conversion was successful in all but one animal, with 12 requiring balloon-catheter assistance.
• No thrombosis, migration, or significant tilting was observed in any of the 49 sheep. Filter components incorporated into the IVC wall within 4 weeks, with no intimal growth on the removed head.

Conclusions:

• The VenaTech Convertible IVC filter demonstrated successful implantation in all subjects.
• Filter conversion via head removal was feasible at various time points, indicating potential for easier retrieval.
• The study supports the safety and efficacy of this convertible IVC filter design.