Tethered IVC Filter Retrieval Funnel for Tilted Filter Capture
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Solution Overview
Problem
Existing temporary IVC filters are difficult to retrieve due to instability and orientation issues, exacerbated by blood flow and clots, making capture with snares challenging.
Innovation Solution
An elongate retrieval device with a braid structure at its distal end, featuring a funnel-shaped apparatus and tethers configured for improved capture, including a braid with a proximal opening that can be closed by a non-spliced loop and crossing tethers, providing enhanced stability and ease of use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a hook-like feature is used for filter retrieval, then the filter can be captured with snares, but capture difficulty increases when the filter is tilted or off-kilter in placement
Solution Approach 1:
The retrieval device is divided into multiple functional segments: a capture mechanism (snare loop), a tether system for positioning, and a funnel-shaped apparatus for guiding the filter. This segmentation allows each component to address specific challenges independently, with the funnel guiding the filter regardless of orientation while the snare captures it securely.
Solution Approach 2:
The funnel-shaped apparatus acts as an intermediary between the snare loop and the filter hook. It provides a guided pathway that accommodates various filter orientations, translating the filter's position into effective capture by the snare loop through the intermediary funnel structure.
2Ease of manufacture
If the filter is not anchored stably in the IVC, then placement is simple, but constant blood flow and clots disorient the filter making recapture difficult
Solution Approach 1:
The retrieval device performs preliminary positioning actions through the funnel-shaped apparatus and tether system before capture is attempted. The funnel guides the filter into the correct position and orientation relative to the snare loop, while tethers maintain stable anchoring during the procedure, ensuring reliable recapture despite blood flow and clots.
Solution Approach 2:
The tether system provides continuous feedback on the filter's position and orientation relative to the retrieval device. This allows real-time adjustment of the funnel and snare configuration to accommodate filter movement caused by blood flow and clots, maintaining reliable capture conditions.
3Device complexity
If a simple snare loop is used for capture, then the device complexity is low, but capturing tilted or off-kilter filters becomes difficult
Solution Approach 1:
The funnel-shaped apparatus adds a dimensional guiding structure that accommodates filters from various angles and orientations. This three-dimensional funnel geometry allows the simple snare loop to effectively capture filters regardless of their initial orientation by translating multi-dimensional positioning into a controlled capture interface.
Data Source
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AI summary
The embodiments described relate to retrieving temporary Inferior Vena Cava (IVC) filters and other endovascular implants or foreign bodies. Features are provided for effective actuation in closing an inner aperture of the embodiments.