Covered Stent Membrane Weave for Easier In-Situ Fenestration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current stent graft materials, such as polyethylene terephthalate (PET), are difficult to puncture for in-situ fenestration due to high tensile and puncture resistance, leading to complex operations and risks of endoleak, branch vessel damage, and reduced graft durability.
Innovation Solution
A graft with a basic area and fenestration-friendly area formed by interweaving warp and weft yarns, where yarns reverse direction more frequently in the fenestration-friendly area, reducing bending stiffness and density to facilitate puncture and fenestration, while maintaining structural integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If PET fabric with high tensile and puncture resistance is used, then graft strength and durability are improved, but ease of puncture for in-situ fenestration deteriorates
Solution Approach 1:
The patent applies local quality by creating a fenestration-friendly area with a specific interweaving pattern that has lower puncture resistance compared to the basic area. This localized structural modification allows easy puncture at the fenestration site while the rest of the graft maintains its high strength characteristics for durability and leak prevention.
Solution Approach 2:
The graft is segmented into two distinct areas: a basic area with standard interweaving for structural integrity and a fenestration-friendly area with modified interweaving for easy puncture. This segmentation allows each area to optimize its properties for its specific function, resolving the contradiction between overall strength and localized puncturability.
2Reliability
If graft puncture is facilitated by reducing porosity, then endoleak risk is reduced, but puncture difficulty increases
Solution Approach 1:
The fenestration-friendly area is designed with a specific interweaving pattern that creates localized porosity suitable for puncture, while the basic area maintains lower porosity to prevent endoleak. This local differentiation allows the graft to be both easy to puncture and reliable in preventing endoleak.
Solution Approach 2:
The patent changes the physical parameters (porosity, density, bending stiffness) of the graft material in the fenestration-friendly area compared to the basic area. These parameter changes are localized and controlled through the interweaving pattern, enabling easy puncture without compromising overall endoleak prevention.
3Reliability
If in-situ fenestration is performed with conventional PET graft, then procedural complexity increases and operation time extends, but success rate remains low
Solution Approach 1:
The graft is pre-designed with a fenestration-friendly area that has optimized structural properties for easy puncture. This preliminary structural preparation eliminates the need for complex intraoperative modifications, reducing procedural complexity and increasing success rate by making the puncture step straightforward when performed.
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The present disclosure relates to the technical field of covered stents, and provides a cover membrane, a covered stent and a cover membrane manufacturing method. The cover membrane is provided with a base area and an easy fenestration area; in the base area, any warp yarn is deflected between a surface layer and an inner layer every time the warp yarn is interwoven with j weft yarns, and any weft yarn is deflected between the surface layer and the inner layer every time the weft yarn is interwoven with k warp yarns; and in the easy fenestration area, at least one warp yarn is deflected between the surface layer and the inner layer every time the at least one warp yarn is interwoven with m weft yarns, and at least one weft yarn is deflected between the surface layer and the inner layer every time the at least one weft yarn is interwoven with n warp yarns, wherein one of m and n is greater than one of j and k, and is greater than or equal to the other one of j and k, and the other one of m and n is greater than or equal to j, and is greater than or equal to k. Membrane rupture and fenestration are easy in the easy fenestration area, the cover membrane would not break or fall off, embolism can be prevented, the occurrence of endoleaks can be reduced, and in situ fenestration positions and number and fenestration shapes can be diversified, thereby adapting to variable branch blood vessel physiological structures of patients.