Hooked Wire Stent Weave for Precise Deployment and Re-Constraint
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Solution Overview
Problem
Existing stents face issues such as migration from their deployed position, difficulty in positioning due to foreshortening during deployment, and tissue ingrowth leading to complications in removal and repositioning.
Innovation Solution
A stent design featuring a tubular scaffold formed of a single filament woven into a plurality of open cells with varying sizes and shapes, including large and small open cells arranged in helical rows, with hooked sections at apices to prevent foreshortening and allow for re-constraint, and a covering to prevent tissue ingrowth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the stent is made compressible and flexible to assist in delivery, then the stent can be delivered through narrow catheters, but the stent has a tendency to migrate from its originally deployed position
Solution Approach 1:
The stent transitions from a compressed dynamic state during delivery to an expanded stable state at deployment. The weave structure allows dynamic compression for delivery while maintaining stability when expanded, resolving the contradiction between deliverability and position stability.
Solution Approach 2:
The stent changes its physical parameters (radius, stiffness, cell size) from a compressed delivery state to an expanded deployed state. This parameter transformation enables the stent to be flexible during delivery while providing stable support after deployment.
2Ease of operation
If the stent is made highly compressible for delivery, then the stent can be delivered through smaller catheters, but the stent experiences foreshortening during deployment making positioning difficult
Solution Approach 1:
The dynamic weave structure allows controlled expansion that minimizes foreshortening. The interwoven filaments can slide and rotate during expansion, reducing the axial shortening effect and improving positioning precision while maintaining deliverability.
3Strength
If the stent is deployed to provide support, then the stent maintains patency of the structure, but tissue ingrowth occurs leading to complications in removal and repositioning
Solution Approach 1:
The open cell structure provides controlled porosity that allows tissue ingrowth to be managed. The large open cells facilitate controlled tissue interaction while the overall structure maintains strength, and the ability to compress the stent enables removal by reversing the expansion that caused tissue ingrowth.
4Strength
If the stent has a traditional woven structure, then the stent provides structural support, but the stent cannot be easily re-constrained for repositioning
Solution Approach 1:
The dynamic weave structure allows the stent to be re-constrained by compressing it back into a deliverable configuration. The interwoven filaments can slide and rotate, enabling the stent to transition between expanded and compressed states multiple times, providing adaptability for repositioning while maintaining structural support.
Data Source
AI summary
A stent is disclosed. The stent includes a tubular scaffold extending from a first end to a second end in which the tubular scaffolding is formed of a single filament woven to form a plurality of open cells throughout the tubular scaffold. Each of the open cells may be formed as a parallelogram shape defined by two pairs of opposing linear sections of the filament and hooked sections of the filament at each apex of the plurality of open cells, wherein each of apices of the plurality of open cells includes a hooked region in which the single filament is intertwined with itself and changes weaving direction. The open cells may include first and second helical rows of small open cells, and a first helical row of large open cells positioned therebetween.