In vitro evaluation of caval filters

Area of Science:

• Biomedical Engineering
• Vascular Surgery
• Medical Device Development

Background:

• Inferior Vena Cava (IVC) filters are crucial for preventing pulmonary embolism.
• Existing filters have limitations, necessitating the development of improved designs.
• Evaluating the efficacy of novel and commercially available IVC filters is essential.

Purpose of the Study:

• To assess the clot-trapping efficacy of commercially available (Mobin-Uddin, Greenfield) and experimental (Amplatz, Günther, Gianturco) IVC filters.
• To identify filter designs with superior performance in simulated inferior vena cava conditions.
• To provide insights for the development of more secure and effective IVC filters.

Main Methods:

• Simulated inferior vena cava model using polyethylene tubes.
• Testing with standardized clots (3 cm length, 6 mm or 9.2 mm diameter).
• Evaluation of clot trapping, filter integrity, and migration under pressure.

Main Results:

• Mobin-Uddin and Amplatz filters failed due to overload, with clots bypassing the filter.
• The Günther filter successfully trapped all clots but experienced downstream migration when occluded.
• Greenfield and Gianturco (bird's nest) filters allowed clot passage at normal pressures.
• All tested filters demonstrated suboptimal performance in clot trapping or stability.

Conclusions:

• No single filter demonstrated optimal performance, highlighting areas for design improvement.
• The Günther filter's design shows potential, with strengthening of anchoring struts proposed for enhanced security and efficacy.
• Further research and development are needed to optimize IVC filter design for robust clot retention and stability.