Anti-migration Biliary Stent with Dual Retaining Members
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Solution Overview
Problem
Existing stents used in the biliary system face challenges in maintaining position and preventing migration when additional stents are placed within the same duct, leading to potential displacement and reduced effectiveness in maintaining patency.
Innovation Solution
A stent design featuring a generally tubular body with a curved proximal portion and straight distal portion, including first and second retaining members that extend radially outward from a common longitudinal axis, allowing for secure positioning and easy repositioning within the duct, thereby preventing migration and facilitating drainage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional stents with retaining members are placed in the biliary duct, then the stent can be retained in position, but the stent may be pushed too far into the duct when additional stents are placed
Solution Approach 1:
The stent employs a dynamic retention mechanism where the first retaining member can be repositioned along the stent body. This allows the stent to transition from a fixed retention state during initial placement to a flexible repositioning state when additional stents need to be inserted, resolving the contradiction between position stability and repositioning capability
Solution Approach 2:
The retaining function is segmented into two distinct members: a first retaining member for initial positioning and a second retaining member for final securing. This segmentation allows the first retaining member to be temporarily adjusted or repositioned during the procedure without compromising the overall stent function, enabling both stable retention and operational flexibility
2Adaptability or versatility
If stents are made flexible to accommodate bodily movement, then the stent can move with the passageway, but the stent may migrate to unintended positions
Solution Approach 1:
The stent applies local quality by making only specific portions flexible while maintaining rigidity in other areas. The stent body has flexible sections that accommodate passageway movement, while the retaining members and their attachment points provide localized rigid structures that prevent migration, thus resolving the contradiction between adaptability and position maintenance
Solution Approach 2:
The stent incorporates curved or spiral retaining members that can naturally follow the contours of the passageway while maintaining their retention function. The curved geometry allows these members to accommodate bodily movements and passageway shape changes while their engagement with the passageway wall prevents unwanted migration, balancing flexibility and position stability
Data Source
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AI summary
A stent is provided. The stent includes a generally tubular body having a lumen defined therethrough. The body includes a proximal portion having a curved portion where the curved portion is configured for placement proximal to a sphincter. The body also includes a substantially straight distal portion having first and second retaining members. The second retaining member is positioned on the distal portion and the first retaining member is positioned proximal to the second retaining member. The first and second retaining members are positioned on a common longitudinal axis extending along a wall of the distal portion and the first and second retaining members extend away from the body in a common direction so that a free end of the first retaining member and a free end of the second retaining member extend away from a distal end of the body.