Bioabsorbable Coil Bifurcation Stent Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current stent technologies for treating coronary bifurcation lesions have lower procedural success rates and worse clinical outcomes due to residual stenosis, blood flow disruption, and chronic foreign body reactions, particularly when using non-bioabsorbable stents and the provisional stenting approach.
Innovation Solution
A bioabsorbable dedicated bifurcation stent with a tripartite structure, convertible between a furled and expanded state, featuring coiled fibers and longitudinal supporting fibers made of biodegradable polymers, which can be implanted in both the main and side-branches to physically support the artery walls and elute drugs to prevent restenosis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If two separate stents are used to treat bifurcation lesions, then the stent can cover both main and side branches, but the overlapping site disrupts blood flow and induces thrombus formation
Solution Approach 1:
The patent merges two separate stent structures into a single integrated bifurcation stent design where the first and second stent bodies are connected through shared components (common struts, connecting elements) to form a unified structure that eliminates overlapping sites while maintaining coverage of both main and side branches
Solution Approach 2:
The stent is segmented into distinct first and second stent bodies that branch from a common base structure, allowing each segment to independently support its respective vessel while avoiding the need for overlapping placement of separate stents
2Strength
If a standard non-bioabsorbable stent is used, then the stent provides long-term structural support, but it causes chronic foreign body reactions
Solution Approach 1:
The patent changes the material parameter from permanent non-bioabsorbable materials to bioabsorbable materials that degrade over time, transforming the stent from a permanent implant to a temporary support structure that eliminates chronic foreign body reactions while maintaining necessary structural support during the critical healing period
Solution Approach 2:
The bioabsorbable stent is designed to be temporarily discarded into the body environment, providing structural support during the healing period and then naturally degrading and being absorbed by the body, eliminating the need for permanent foreign material while maintaining vessel patency
3Object-generated harmful factors
If a bioabsorbable stent is used, then chronic foreign body reactions are reduced, but the stent must maintain high strength during degradation
Solution Approach 1:
The patent employs composite material structures combining bioabsorbable polymers with reinforcing elements or multi-layer constructions that maintain high strength-to-weight ratios, allowing the stent to provide adequate structural support throughout the degradation process while eventually being absorbed by the body
Solution Approach 2:
The stent is designed with dynamic properties where its mechanical strength evolves over time as the material degrades, with the structure maintaining high strength initially and gradually reducing strength as it is absorbed, matching the healing timeline of the vessel
4Strength
If the stent is designed to expand to large diameter, then it can effectively support the artery walls, but the furled state must be compact for delivery
Solution Approach 1:
The stent is designed in a nested configuration where the first and second stent bodies are arranged in a compact furled state that fits within a delivery catheter, with components nested within each other to minimize delivery profile while maintaining the capability to expand to the required large diameter for effective artery wall support
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 bioabsorbable bifurcation stent provides high strength and flexibility, effectively treating bifurcation lesions with reduced risk of chronic foreign body reactions and improved clinical outcomes by maintaining an open lumen and preventing restenosis, while degrading over time.
Implementation Method 1
The coil structure includes central and peripheral lobes which are arranged such that, in the expanded state, the peripheral lobes merge into the central lobes, yielding a coil structure of a larger diameter as compared to the furled state
Implementation Method 2
All of the above-mentioned coiled fibers and reinforcing fibers are constructed of bioabsorbable polymeric material
Data Source
AI summary
A bioabsorbable, expandable coil bifurcation stent having a first, second, and third segment, in which the second and third segments are extensions of a coiled fiber in the first segment. Also disclosed is a three-segment expandable coil bifurcation stent in which the second and third segments extend from supporting fibers in the first segment. Further disclosed is an expandable bifurcation stent in which supporting fibers in the first segment also support the second and third segments. The three segments are independently adjustable to fit varied geometries.