Multi-Flange Stent Structure for Anti-Migration Anchoring
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Solution Overview
Problem
Existing medical devices used for bypassing the duodenum face challenges in preventing migration into the small intestine or proximally into the stomach, necessitating improved methods and devices for controlling and regulating the passage.
Innovation Solution
A self-expanding stent with a radially expanding tubular framework and multiple flange structures, including a third flange spaced from the first flange to provide additional radial force, preventing migration during peristalsis and turbulence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a stent is deployed in a vessel, then the vessel is held open and blood flow is maintained, but the stent may migrate to a different location in the vessel
Solution Approach 1:
The stent is divided into multiple individual cells or struts that can be independently formed into asymmetric shapes. Each cell contributes to the overall anchoring function while maintaining the ability to provide radial support, thus achieving migration resistance without compromising structural simplicity
Solution Approach 2:
The stent incorporates asymmetric cell geometries with different shapes, sizes, or configurations at different locations along the stent body. This asymmetry creates directional anchoring forces that prevent stent migration while maintaining radial expansion capability, resolving the contradiction between positioning stability and structural complexity
2Reliability
If an asymmetric stent design is used to prevent migration, then stent positioning is improved, but manufacturing precision requirements increase
Solution Approach 1:
The asymmetric stent design is configured such that the asymmetry is intentionally built into the base structure before deployment. The asymmetric cells are designed to achieve self-centering or self-aligning behavior upon expansion, reducing the need for high-precision positioning during manufacturing and installation while maintaining reliable positioning in the vessel
Solution Approach 2:
The stent employs controlled variations in cell parameters (such as cell size, shape, or spacing) along its length to create asymmetric anchoring zones. These parameter changes are designed within tolerances that accommodate typical manufacturing variations, ensuring that the asymmetric geometry provides migration resistance without requiring extreme manufacturing precision
3Reliability
If the stent is made larger to improve anchoring, then migration resistance increases, but the risk of vessel damage increases
Solution Approach 1:
The stent features localized asymmetric cell designs at specific positions (such as distal and proximal ends) where anchoring is most critical, while maintaining more conventional cell structures in intermediate sections. This local quality approach concentrates the migration-preventing asymmetric geometry where it is most needed, providing effective anchoring without unnecessarily increasing the overall stent size and associated vessel damage risk
Data Source
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AI summary
An example medical device may include a stent including a radially expanding tubular framework having a radially outward surface, a radially inward surface, a first end region, a second end region, a medial region positioned between the first end region and the second end region, and a lumen extending from the first end region to the second end region. A first flange structure may be positioned near the first end region, and a second flange structure may be positioned near the second end region. One of the first end region or the second end region may include a third flange structure.