A new self-convertible inferior vena cava filter:in vitro experimental evaluation / 中国组织工程研究

ABSTRACT

BACKGROUND: Inferior vena cava filter is an effective way to prevent fatal pulmonary embolism. The existing filters have some shortcomings that limit the clinical application. OBJECTIVE:To evaluate the feasibility and capture efficiency of a new self-convertible inferior vena cava filter(SCF)in vitro. METHODS: The biodegradable switch was constructed of a copolymer of ε-caprolactone and L-lactide (75%/25%, PCLA75). The biodegradable switch bound together with the apices of the convertible struts to make the self-convertible filter. The deformability and capture efficiency of the filter were tested in an in-vitro flow model with three different diameters (22, 25, 28 mm). A total of 15 filters were implanted both in the vertical and horizontal positions, and the tilt angle of the filter was tested after release. To accelerate switch degradation, a lipase perfusate was injected into the flow model and refreshed every 8 hours until conversion. RESULTS AND CONCLUSION: (1) All the filters were successfully implanted without tilting, both in the vertical and horizontal positions in the three different diameter models. (2) All the 15 SCFs were converted successfully without tilting, structural damage, and displacement. (3) The capture efficiency of the SCF had significant difference between the different diameter of the models, the size of the embolus and the position of the two models (P < 0.001). The mean capture efficiency was 82.5%, and the capture efficiency exhibited a downward trend with the increase of pipe diameter, the decrease of emboli size, and the position of pipeline changing from vertical to horizontal. All these results show that the SCF is feasible and highly efficient.