Endoluminal Prosthesis Radial Strength Segmentation
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Solution Overview
Problem
Existing endoluminal prostheses, particularly those used in carotid arteries, face challenges in providing sufficient radial strength to maintain a clear lumen while minimizing material usage, as excessive metal-to-artery ratios can lead to restenosis and mechanical rigidity issues, and their complex geometry may cause vessel wall damage.
Innovation Solution
A self-expanding endoluminal prosthesis with a tubular body comprising serpentines and bridges, optimized for radial strength in the middle portion and minimal material usage in end portions, featuring a specific arrangement of serpentines and bridges that provide high radial compression strength and flexibility, along with radiopaque markers for precise placement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the endoluminal prosthesis uses more material to increase radial strength, then the support capability is improved, but the metal-to-artery ratio increases leading to restenosis and mechanical rigidity issues
Solution Approach 1:
The prosthesis is divided into multiple segments or struts arranged in a pattern that provides radial strength only where needed (at the stenosis location) while leaving end portions with minimal material. This segmentation allows concentrated support in the middle portion without excessive metal throughout the entire length.
Solution Approach 2:
The prosthesis structure varies along its length, with the middle portion having higher radial strength characteristics to support the stenosis area, while the end portions have reduced material content. This local differentiation of structural properties optimizes the metal-to-artery ratio by providing strength only where clinically necessary.
2Strength
If the endoluminal prosthesis uses complex geometry to enhance structural support, then the radial strength is improved, but the vessel wall may be damaged by pinching or hanging
Solution Approach 1:
The prosthesis employs curved or serpentine strut designs rather than sharp angular geometries. These curved structures provide the necessary radial support while following the natural contours of the vessel, eliminating pinching points and reducing mechanical irritation to the vessel wall.
Solution Approach 2:
The prosthesis incorporates flexible connecting elements or thin film structures that can adapt to vessel movement and pulsation without creating rigid pinching points. These flexible components maintain structural integrity while minimizing harmful mechanical interactions with the vessel wall.
3Quantity of substance
If the endoluminal prosthesis uses minimal material in end portions, then the metal-to-artery ratio is reduced, but the overall structural support may be compromised
Solution Approach 1:
The prosthesis is segmented into high-support zones (middle portion) and low-support zones (end portions). The segmented design ensures that minimal material in the end portions does not compromise overall structural integrity, as the critical middle section maintains adequate radial strength to support the stenosis.
Solution Approach 2:
Different sections of the prosthesis have different material densities or structural characteristics optimized for their specific functions. The end portions use minimal material suitable for their anchoring function, while the middle portion uses sufficient material to provide the required structural support, achieving an optimal overall metal-to-artery ratio.
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 prosthesis achieves optimal metal-to-artery ratios, ensuring effective support and flexibility, reducing the risk of restenosis and vessel damage, while allowing for precise placement and maintaining a clear lumen, even in tortuous vessels.
Implementation Method 1
self-expanding, such as those made of superelastic or shape memory material, such as Nitinol
Implementation Method 2
self-expanding, such as those made of superelastic or shape memory material, such as Nitinol
Data Source
AI summary
An endoluminal prosthesis comprises a tubular body which can be expanded about a longitudinal axis. A plurality of serpentines extend in a substantially circumferential direction. Each comprises arm portions and bend portions which join two subsequent arms. The bends facing an adjacent serpentine are circumferentially offset relative to the respective opposite bends of the contiguous serpentine, both when the prosthesis is collapsed and when the prosthesis is expanded. A first portion comprises at least two adjacent serpentines interconnected by at least one bridge, and at least two bends situated at the shortest longitudinal distance between the two serpentines is not connected by a bridge. A second portion comprises at least two adjacent serpentines interconnected by a number of bridges equal to the number of pairs of bends of the two serpentines, at the shortest longitudinal distance between the two serpentines.