Stent Collapsing Structure for Repositioning and Removal
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Solution Overview
Problem
The challenge lies in the inability to efficiently reposition or remove stents from the body lumen after deployment, particularly due to foreshortening issues that can lead to incorrect placement and the need for minimal trauma during removal.
Innovation Solution
A collapsing structure comprising an outer filament interwoven with a stent end and an inner filament at engagement points, allowing the stent to be collapsed by pulling the inner filament, thereby enabling repositioning or removal of the stent with minimal trauma.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a stent is deployed in a body lumen, then it provides structural support and maintains patency, but it cannot be repositioned or removed without causing trauma to the patient
Solution Approach 1:
The stent is divided into a body portion and a collapsible end portion. The collapsible end portion can be independently collapsed by pulling the filament, creating a tapered configuration that reduces trauma during removal or repositioning while maintaining structural support at the deployment site
Solution Approach 2:
The stent transitions from a static deployed state to a dynamic collapsible state. The filament allows the stent end to be dynamically collapsed and re-expanded, enabling repositioning or removal without permanent structural compromise to the patient's tissue
2Shape
If direct filament pulling is used to collapse the stent, then the stent diameter is reduced, but excessive force is required causing trauma
Solution Approach 1:
The collapsing force is distributed across multiple filaments and crown structures rather than applied at a single point. This segmentation of the collapsing mechanism distributes the mechanical stress, reducing the peak force required and minimizing trauma to the patient's tissue
Solution Approach 2:
The filament pulls the stent crowns radially inward from the longitudinal axis, collapsing the stent end in a controlled manner. This dimensional approach to force application allows gradual diameter reduction without requiring excessive concentrated force that would cause tissue trauma
3Length of moving object
If the stent is collapsed for removal, then it can be extracted from the body lumen, but the structure becomes difficult to control during the process
Solution Approach 1:
The filament is pre-positioned within the stent structure during manufacturing, with its ends extending beyond the stent body. This preliminary configuration allows the operator to easily grasp and pull the filament for collapse, and to re-grasp it for re-expansion, maintaining control throughout the entire process
Solution Approach 2:
The filament acts as an intermediary control element between the operator and the stent structure. By manipulating the filament, the operator can control the collapse and re-expansion of the stent end without directly manipulating the stent structure itself, maintaining ease of operation throughout the procedure
Data Source
AI summary
A collapsing structure for collapsing the crowns of a stent and method of use thereof are described. The collapsing structure comprises an inner filament engaged to an outer filament. The outer filament is interwoven through at least a portion of the crowns of the stent end so as to create a plurality of loops. The inner filament is interwoven through at least a portion of the loops of the outer filament. Pulling on the inner filament causes the loops of the outer filament to be pulled radially inward, thereby pulling the crowns towards each other to collapse the stent end.