Retrievable Filter Stent for Long-Term Embolic Stroke Prevention
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Solution Overview
Problem
Current Cerebral Embolic Protection Devices (CEPDs) provide limited protection during and shortly after Transcatheter Aortic Valve Replacement (TAVR) procedures, failing to address strokes occurring beyond 2 days post-procedure due to the clogging of long-term devices, and there is a need for a device capable of filtering small debris in the long term to prevent ischemic strokes.
Innovation Solution
A stent-based device with a filter portion featuring parallel, convex struts positioned to divert emboli from entering the artery, coated with materials like graphene oxide and nanoparticles to repel negatively charged clots, and a retrieval system for easy removal, allowing long-term protection against emboli.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If current CEPDs are used for long-term protection, then stroke prevention is improved, but device clogging occurs preventing further use
Solution Approach 1:
The filter portion is designed to be removable from the stent portion, allowing the clogged filter to be extracted and replaced while retaining the stent structure. This resolves the contradiction by enabling long-term stroke prevention through periodic filter replacement rather than complete device removal or continuous clogging.
Solution Approach 2:
The clogged filter portion is discarded and replaced with a new filter, while the stent portion is retained and reused. This approach maintains reliable stroke prevention by regularly replacing the filtering component without wasting the structural stent component.
2Reliability
If filter portion is made to capture small debris, then stroke prevention is improved, but blood flow resistance increases
Solution Approach 1:
The filter portion features parallel convex struts with varying spacing and orientations, creating regions of different filtering intensity. This local variation in structure allows effective capture of small emboli in critical areas while maintaining larger flow channels in other regions, thus reducing overall blood flow resistance.
Solution Approach 2:
The convex (curved) struts are designed to streamline blood flow around them, reducing turbulence and flow resistance compared to flat or sharp-edged structures. The curved geometry allows small emboli to be captured while maintaining smooth flow patterns that minimize energy loss.
3Reliability
If filter portion is made permanent, then stroke prevention is improved, but retrieval difficulty increases
Solution Approach 1:
The device is segmented into a permanent stent portion and a removable filter portion. This segmentation allows the filter to be made permanent in terms of initial placement for stroke prevention, while simultaneously enabling easy retrieval or replacement of the filter portion independently through the engagement/disengagement mechanism.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The device effectively diverts emboli from entering the brain arteries, reducing the risk of ischemic strokes beyond 2 days post-TAVR with minimal impact on blood flow resistance, and can be easily retrieved, providing comprehensive stroke prevention.
Implementation Method 1
coated with materials like graphene oxide and nanoparticles to repel negatively charged clots
Data Source
AI summary
Deflection devices, systems, and methods for the prevention of stroke configured and negatively charged to filter emboli in the bloodstream and prevent advancement into the artery extending from the aortic arch. Devices may be formed as a single structure or a composite device. Additionally, a retrieval system is provided, including a sleeve catheter and a retrieval device slidably disposed therein, the retrieval device including one or more attachment portions configured to engage at least a portion of a device positioned within an artery extending from the aortic arch.