Electrospun Aneurysm Stent Covering for Small-Vessel Delivery
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Solution Overview
Problem
Existing medical devices for treating aneurysms, particularly stents, face challenges in being compressible enough to navigate small, tortuous blood vessels while providing effective endothelial coverage and maintaining structural integrity.
Innovation Solution
A stent with a compressible and expandable mesh structure featuring closed cell rings and an electrospun fabric covering with irregular pores, promoting endothelial cell growth and antithrombogenic properties, allowing for self-expansion and minimal delivery forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a stent is provided with a covering produced from textile materials to occlude aneurysms, then the aneurysm screening function is improved, but the stent wall thickness increases and compressibility is compromised
Solution Approach 1:
The patent employs an electrospun fabric covering with controlled porosity to achieve aneurysm occlusion while maintaining stent compressibility. The porous structure allows blood flow control for aneurysm screening while the fine fiber mat structure keeps wall thickness minimal, resolving the contradiction between screening effectiveness and compressibility.
Solution Approach 2:
The electrospun fabric creates a thin, flexible covering that conforms to the stent structure while maintaining adequate mechanical properties. This thin-film approach provides the necessary aneurysm screening function without significantly increasing wall thickness, thereby preserving stent compressibility for delivery through small cerebral vessels.
2Length of moving object
If the stent wall thickness is reduced to improve compressibility, then delivery to small cerebral blood vessels is improved, but endothelial cell coverage becomes insufficient
Solution Approach 1:
The electrospun fabric's porous structure with controlled pore size and distribution provides adequate surface area for endothelial cell attachment and proliferation while maintaining thin wall thickness. The porosity allows cells to penetrate and colonize the stent surface effectively, ensuring reliable endothelialization despite reduced wall thickness.
Solution Approach 2:
The patent optimizes parameters of the electrospun fabric including fiber diameter, pore size, porosity, and fabric density to achieve the right balance between thin wall thickness and adequate endothelial cell coverage. By controlling these parameters, the covering provides sufficient cell attachment surface while maintaining minimal thickness for compressibility.
3Reliability
If a nonwoven fabric with low porosity is used to achieve complete aneurysm occlusion, then the occlusion effectiveness is improved, but the stent compressibility is limited
Solution Approach 1:
The patent uses an electrospun fabric with optimized porosity that balances occlusion effectiveness and compressibility. The controlled porous structure provides adequate filtration for aneurysm occlusion while the fine fiber mat structure maintains high compressibility, allowing delivery through small vessels. This resolves the contradiction by finding the optimal porosity level that satisfies both requirements.
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 stent achieves long-lasting endothelial coverage, reduced delivery forces, and navigability through small vessels, ensuring effective treatment of aneurysms with minimal vessel disruption.
Implementation Method 1
the covering has irregular pores and a biocompatible coating, allowing for enhanced compressibility and endothelial cell colonization, enabling successful deployment and long-lasting endogenous coverage of aneurysms
Data Source
AI summary
The invention relates to a medical device for treating aneurysms, in particular a stent, including a compressible and expandable grid structure made up of grid elements. The grid structure has at least one closed cell ring which includes at most 12, in particular at most 10, in particular at most 8, in particular at most 6 cells directly adjacent to one another in a circumferential direction of the grid structure. The grid structure is provided at least in certain portions with a covering made of an electrospun fabric which has pores of irregular sizes. The covering includes over a surface area of 100 000 μm2 at least 10 pores which have a size of at least 15 μm2. The covering has a biocompatible, in particular antithrombogenic and/or endothelialization-promoting coating.