Bioabsorbable Flow-Diverting Scaffold for Reduced Thrombosis
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Solution Overview
Problem
Existing metal flow-diverting scaffolds for treating aneurysms pose risks such as thrombosis, hyperplasia, and imaging interference due to their permanence, while bioabsorbable scaffolds have higher thrombogenicity issues.
Innovation Solution
A resiliently deformable tubular body made of a braid of interwoven bioabsorbable polymeric fibers with a porosity range of 5% to 80%, incorporating visualization aids and optional resiliently deformable wires for radial and axial expansion, designed to divert blood flow and deliver therapeutic agents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If metal flow-diverting scaffolds are used, then structural strength and durability are improved, but thrombosis risk and imaging interference increase
Solution Approach 1:
The patent changes the material parameter from permanent metal to bioabsorbable polymer, fundamentally altering the device's interaction with the body. This parameter change reduces thrombosis risk by eliminating permanent foreign body presence while maintaining sufficient structural strength during the critical healing period through optimized polymer composition and scaffold architecture.
Solution Approach 2:
The patent applies the discarding principle by designing a scaffold that is intentionally temporary and meant to be absorbed by the body after serving its flow diversion function. The bioabsorbable material degrades and is eliminated from the body, removing the source of long-term thrombosis risk and imaging interference while providing necessary support during vessel healing.
2Reliability
If metal flow-diverting scaffolds are used, then flow diversion efficacy is improved, but imaging interference and permanent foreign body presence increase
Solution Approach 1:
The patent changes the material parameter from metal to bioabsorbable polymer, which fundamentally alters imaging characteristics. The polymer material does not cause the bright signal artifacts associated with metal on CT and MRI, eliminating imaging interference while maintaining flow diversion efficacy through optimized scaffold porosity and structural design.
Solution Approach 2:
The temporary nature of the bioabsorbable scaffold means it serves its flow diversion function and then is naturally eliminated by the body. This discarding principle removes the source of ongoing imaging interference that would persist indefinitely with permanent metal scaffolds, while ensuring reliable flow diversion during the critical healing period.
3Object-affected harmful factors
If bioabsorbable scaffolds are used, then thrombosis risk is reduced, but structural strength and durability decrease
Solution Approach 1:
The patent employs composite material strategies by using blended polymer compositions (e.g., PLA/PGA copolymers) that combine the benefits of different biodegradable materials. This composite approach optimizes the balance between structural strength needed for immediate flow diversion and biodegradability that reduces long-term thrombosis risk, achieving both goals simultaneously.
Solution Approach 2:
The patent optimizes multiple parameters of the bioabsorbable material including molecular weight, crystallinity, crosslinking density, and polymer composition ratios. These parameter changes allow tuning of the degradation rate to match the healing timeline, ensuring sufficient structural strength is maintained during the critical period when flow diversion is needed, while ultimately degrading to reduce thrombosis risk.
4Adaptability or versatility
If high porosity braid is used, then vascular remodeling is allowed, but flow diversion capability decreases
Solution Approach 1:
The patent optimizes the porosity parameter to a specific range (50-80%) that balances two competing requirements. This parameter optimization allows sufficient open space for vascular remodeling and tissue ingrowth while maintaining enough solid structure to effectively divert blood flow away from the aneurysm, achieving both vascular adaptability and flow diversion reliability.
Solution Approach 2:
The patent applies different local qualities within the scaffold structure by varying fiber density, braid pattern, and porosity in different regions. The scaffold can have higher porosity in areas where vascular remodeling is needed while maintaining lower porosity in regions critical for flow diversion, allowing both functions to coexist through spatial differentiation of structural properties.
Data Source
AI summary
This disclosure relates to scaffolds made of a braid of bioabsorbable polymeric fibers for implantation within a lumen of a mammalian body and, in particular, to such scaffolds that are configured to divert blood flow from a pathology associated with a blood vessel.