Braided Stent End Reinforcement via Wire Looping
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Solution Overview
Problem
Braided stents suffer from reduced radial strength and crush resistance at their open ends due to loose wire ends, which can lead to poor patency and increased risk of thrombus or atherosclerosis formation.
Innovation Solution
The wire ends of the stent are bent to form closed loops and secured using welding or crimp sleeves, with optional polymer encapsulation and increased braid density or radiopaque markers to enhance radial strength and prevent loose ends from embedding into the blood vessel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If braided stents are manufactured with open wire ends, then manufacturing is simpler and faster, but radial strength and crush resistance at the ends are reduced
Solution Approach 1:
The wire ends are bent into loops and secured with crimp sleeves or welding during the manufacturing process, before the stent is deployed. This preliminary action eliminates the weak open ends while maintaining manufacturing efficiency, as the reinforcement is integrated into the braiding process itself.
Solution Approach 2:
The reinforcement structures (loops, crimp sleeves, or welds) are applied specifically at the end regions of the stent where radial strength is needed, rather than uniformly across the entire stent. This localized quality enhancement provides strength where required without unnecessarily increasing complexity elsewhere.
2Device complexity
If wire ends are left open for simplicity, then device complexity is reduced, but the risk of thrombus or atherosclerosis formation increases
Solution Approach 1:
The potentially harmful exposed wire ends are transformed into beneficial closed loops that eliminate the risk of embedding and thrombus formation. The same wire material that could cause harm is reconfigured into a safe, rounded structure that protects the vessel wall.
Solution Approach 2:
By pre-closing the wire ends into loops before deployment, the invention prevents the harmful effect of embedding and subsequent thrombus formation. This preliminary anti-action eliminates the risk factor before the stent enters the bloodstream.
3Strength
If reinforcement is added to stent ends, then radial strength and crush resistance are improved, but manufacturing complexity increases
Solution Approach 1:
The reinforcement process is merged with the existing braiding and heat-setting process. Crimp sleeves are applied and heat-set along with the stent structure, and welding is performed as part of the end-formation process. This integration eliminates separate manufacturing steps and reduces overall complexity.
Solution Approach 2:
The braiding machine itself is used to form the loops and apply reinforcements during the normal manufacturing process. The system performs the reinforcement function as part of its standard operation, requiring no additional external equipment or complex multi-step processes.
4Strength
If braid density is increased at stent ends, then radial strength is enhanced, but conformability may be reduced
Solution Approach 1:
The increased braid density is applied locally only at the end regions of the stent where reinforcement is needed, while the mid-section maintains its original, more compliant braid density. This spatial differentiation allows the stent to be strong at the ends where it anchors to the vessel wall, while remaining conformable in the middle section that needs to adapt to vessel curvature.
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 solution provides improved radial strength and crush resistance at the stent ends, reducing the risk of embedding and enhancing visibility during imaging, while maintaining durability and flexibility.
Implementation Method 1
The wire ends of the stent are bent to form closed loops and secured using welding or crimp sleeves
Implementation Method 2
heat setting the hollow tubular body
Data Source
AI summary
A stent (10) includes a hollow tube (12) including interlaced metal strands (14); and a reinforcement providing radial strength reinforcement at an end (16, 18) of the hollow tube. In some examples, the reinforcement includes a first reinforcement at a first end (16) of the hollow tube (12); and a second reinforcement at a second end (18) of the hollow tube opposite the first end of the hollow tube.