Pseudo-Hooked Wire Stent Structure for Low-Foreshortening Placement
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Solution Overview
Problem
Existing stents face issues such as migration from their deployed position, foreshortening during deployment, difficulty in repositioning, and tissue ingrowth, which complicates their use in medical procedures like ERCP.
Innovation Solution
A stent design featuring a tubular scaffold formed from a single filament with pseudo hooked segments and varying open cell sizes and shapes, including helical rows of large and small cells, to minimize foreshortening and allow for re-constraint after partial deployment, while being covered to prevent tissue ingrowth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a stent is made compressible and flexible to assist in delivery, then the stent can be delivered through catheters, but the stent has a tendency to migrate from its originally deployed position
Solution Approach 1:
The stent employs a dynamic structure with articulated cells that can transition between compressed and expanded states. The pseudo-hooked segments allow the stent to adapt its configuration during delivery and deployment, maintaining flexibility for navigation while providing stability when deployed through the interlocking mechanism of overlapping bends.
2Strength
If a stent is designed with traditional structure, then it provides structural support, but it experiences foreshortening during deployment
Solution Approach 1:
The stent incorporates pseudo-hooked segments with specific curvature profiles that reduce foreshortening during expansion. The bent configurations are designed with optimized radii and angles that maintain longitudinal spacing between cells, preventing excessive compression of the stent length during the transition from delivered to expanded state.
3Reliability
If a stent is deployed in a body lumen, then it provides support and maintains patency, but repositioning becomes difficult
Solution Approach 1:
The articulated cell structure with pseudo-hooked segments allows the stent to be dynamically adjusted after initial deployment. The interlocking bends can be selectively engaged or disengaged, enabling repositioning or partial withdrawal while maintaining structural integrity and support function throughout the adjustment process.
4Productivity
If a stent is left uncovered, then it maintains patency, but tissue ingrowth occurs
Solution Approach 1:
The stent incorporates a thin flexible covering that conforms to the tubular scaffold structure. This covering acts as a barrier to tissue ingrowth while maintaining the patency of the lumen, allowing the stent to provide structural support without the harmful effect of tissue proliferation into the lumen.
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 scaffold is formed of a single filament shaped 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 pseudo 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 pseudo hooked region in which first and second bends of the single filament overlap one another. 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.