Fracturable Coating Stent-Grft for Vessel Adaptability
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Solution Overview
Problem
Conventional medical devices such as stent-grafts and vascular grafts face challenges in maintaining a stable size and fit within varying vessel dimensions, often requiring multiple device sizes and risking infolding or migration due to mismatched diameters.
Innovation Solution
A fibrillated porous substrate material with bent fibrils coated with a fracturable material, such as thermoplastic fluoropolymer FEP, allows for permanent extension of device dimensions by tensile force, enabling customization and self-expansion with minimized radial force against the vessel wall.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a stent-graft is manufactured with a fixed size to match specific vessel dimensions, then the fit and stability in that specific vessel size is improved, but the adaptability to different vessel sizes deteriorates
Solution Approach 1:
The stent-graft incorporates a fracturable coating that transitions the device from a static fixed-size structure to a dynamic adjustable structure. The coating remains intact during delivery and initial deployment, providing structural stability, then can be fractured to allow permanent extension of the device dimensions to match larger vessel diameters, thus achieving both stability and adaptability
Solution Approach 2:
The device allows change in the dimensional parameters of the stent-graft by fracturing the coating material. This enables the device to transition from one size configuration to another, allowing customization to match different vessel diameters and lengths, thereby resolving the contradiction between fixed-size stability and multi-size adaptability
2Adaptability or versatility
If multiple device sizes are used to accommodate different vessel dimensions, then the adaptability to various vessel sizes is improved, but the device complexity and risk of infolding or migration deteriorates
Solution Approach 1:
A single stent-graft design with a fracturable coating performs multiple functions: it can be deployed in its original size for smaller vessels and then extended to larger sizes for bigger vessels. This universal design eliminates the need for multiple specialized devices, reducing complexity while maintaining broad adaptability across different vessel dimensions
Solution Approach 2:
The fracturable coating enables the device to dynamically change its dimensional parameters from a compact delivery configuration to an expanded functional configuration. This dynamic capability allows one device to replace multiple fixed-size devices, reducing the complexity of managing multiple device sizes while maintaining versatility
3Manufacturing precision
If the stent-graft is self-expanding with high radial force, then the immediate expansion and vessel wall apposition is improved, but the risk of vessel wall damage and migration deteriorates
Solution Approach 1:
The expansion process occurs in periodic stages: first, the stent-graft self-expands to provide initial structural support; second, the fracturable coating is fractured to allow controlled permanent extension; third, the device achieves final apposition. This staged approach distributes the expansion force over time, preventing sudden high radial forces that could damage the vessel wall while ensuring accurate final positioning
Solution Approach 2:
The radial force parameter is modulated through the fracturable coating mechanism. The coating constrains the self-expansion to provide controlled, moderate radial force initially, then fractures to allow the device to expand to its full predetermined size with reduced incremental force, minimizing vessel wall damage while achieving precise dimensional matching
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
This solution allows for customizable device sizes, reduces the risk of infolding, and enables the use of a single device for a broader range of vessel sizes, ensuring a wrinkle-free lumen and stable deployment with reduced migration risk.
Implementation Method 1
A fracturable coating applied to a porous substrate material having a microstructure of bent fibrils may be used to create an article that can be, during normal use, permanently increased in at least one dimension by the application of a tensile force
Implementation Method 2
Thermoplastic coatings on such substrates are sometimes used as adhesives for bonding together different components of an article
Data Source
AI summary
A stent-graft having a smaller compacted diameter suitable to allow the stent-graft to be transported through a body conduit to a desired site. The stent-graft is deployed at the desired site by self-expanding to a first larger diameter from the smaller compacted diameter. The stent-graft has at least one flared end when self-expanded to the first larger diameter. The stent graft is further diametrically expandable by the application of force such as the inflation of a catheter balloon within the stent-graft to a still larger, maximum second diameter that is equal to about the maximum diameter of the flared end.