Self-Expanding Stent Delivery via Core Advancement Wire
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Solution Overview
Problem
Existing stent delivery systems face challenges in navigating the constrained and tortuous neurovasculature, particularly in tiny vessels like those in the brain, due to radial expansion and buckling issues when pushing or pulling the stent, which can cause unnecessary trauma or rupture.
Innovation Solution
A system that allows the self-expanding stent to be moved within a catheter by dragging or pulling from the distal or proximal portions, using a core advancement wire with radiopaque markers or stop members to engage anchor members, reducing the force needed for distal or proximal movement and minimizing radial expansion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the stent is pushed distally or pulled proximally in the catheter, then the stent can be delivered to the treatment site, but the stent experiences axial compression and radial expansion causing trauma to the blood vessel
Solution Approach 1:
The stent is divided into multiple segments or struts that can independently flex and conform to the catheter shape, allowing the stent to navigate tortuous vasculature without expanding radially and causing vessel trauma
Solution Approach 2:
The stent transitions from a compressed low-profile state during delivery to an expanded state at the treatment site, changing its physical parameters to minimize trauma during delivery and provide reinforcement only when needed at the target location
2Ease of operation
If the stent is constrained within the catheter, then the stent can be navigated through tortuous vasculature, but the stent cannot provide selective reinforcement
Solution Approach 1:
The stent is designed with dynamic properties allowing it to remain flexible and constrained during navigation, then transition to a rigid expanded state at the treatment site to provide selective reinforcement, with the ability to dynamically change its mechanical properties based on location
Solution Approach 2:
The stent is pre-positioned and constrained within the catheter during navigation through tortuous vasculature, then deployed at the predetermined treatment site to provide reinforcement, ensuring navigation ease before achieving the reinforcement function
3Productivity
If force is applied to push or pull the stent, then the stent can be moved within the catheter, but excessive force causes buckling and radial expansion
Solution Approach 1:
The stent is constructed with flexible materials and a thin-profile design that allows it to be pushed or pulled through the catheter with minimal force while maintaining shape stability, preventing buckling and unintended radial expansion during delivery
Solution Approach 2:
The stent design incorporates a low radial profile during delivery that transitions to a full radial expansion at the treatment site, using dimensional transformation to enable easy movement during delivery while maintaining shape stability and providing reinforcement when deployed
Data Source
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AI summary
A system for delivering and releasing a self-expanding stent includes a catheter, a tubular self-expanding stent configured to be constrained from expanding when the tubular self-expanding stent is contained within the catheter, and a core advancement wire disposed within and extending through a lumen of the tubular self-expanding stent. One or more stop members on the core advancement wire engage one or more anchor members on the stent when the core advancement wire is translated longitudinally toward the one or more anchor members.