Stent Anchoring System With Radial Barbs
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Solution Overview
Problem
Implantable stents often migrate from their deployed position due to peristalsis in body lumens, such as the esophageal or gastrointestinal tract, leading to complications like stent migration and reduced efficacy in maintaining luminal patency.
Innovation Solution
The design of a stent with an elongated tubular member and interwoven filaments that change configuration from collapsed to expanded, featuring barbs that are initially constrained radially inward but extend outward upon deployment, providing anti-migration features by anchoring to the lumen walls.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the stent is designed to be compressible and flexible for delivery, then the stent can be delivered through body lumens, but the stent has a tendency to migrate from its deployed position due to peristalsis
Solution Approach 1:
The stent incorporates barbs that dynamically change their radial position from constrained (radially inward) in the collapsed configuration to extended (radially outward) in the expanded configuration. This dynamic behavior allows the stent to be delivered in a compressed state and then securely anchor after deployment, resolving the contradiction between deliverability and position stability.
Solution Approach 2:
The stent is segmented into multiple barbs distributed along its length, each capable of independent radial extension. This segmentation allows different portions of the stent to anchor at different times and positions, providing progressive stabilization while maintaining the overall flexibility needed for delivery through body lumens.
2Reliability
If the stent includes barbs that extend radially outward to anchor to tissue, then the stent resists migration, but the barbs may interfere with delivery through body lumens
Solution Approach 1:
The barbs are designed to be radially movable, transitioning from a constrained inward position during delivery to an extended outward position after deployment. This dynamic reconfiguration allows the stent to pass through delivery catheters in a compact state and then engage tissue for anchoring once deployed, eliminating the trade-off between deliverability and anchoring capability.
Solution Approach 2:
The barbs are pre-positioned in a constrained state within the stent structure before deployment. This preliminary configuration allows the stent to be delivered without interference from the barbs, and the constraint is released only after the stent is properly positioned, enabling safe delivery followed by effective anchoring.
3Ease of operation
If the barbs are constrained radially inward in the collapsed configuration, then the stent can be delivered safely, but the barbs must be released to extend outward for anchoring
Solution Approach 1:
The barb constraint mechanism is merged with the stent's expansion mechanism itself. The radial expansion of the stent body automatically provides the force needed to move the barbs from their constrained inward position to their extended outward position, eliminating the need for separate constraint release mechanisms and reducing overall device complexity.
Solution Approach 2:
The stent structure itself serves to constrain and then release the barbs. As the stent expands from its collapsed to expanded configuration, the changing geometry of the stent body automatically moves the barbs outward, allowing the device to self-regulate the barb positioning without external intervention or complex additional mechanisms.
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 stent effectively minimizes migration and maintains luminal patency by securely anchoring to the tissue, ensuring the stent remains in place and functions as intended, even in areas with peristaltic motion.
Implementation Method 1
The elongated tubular member is configured to move between a collapsed configuration and an expanded configuration. In the collapsed configuration, the plurality of cells have a first profile and in the expanded configuration the plurality of cells have a second profile different from the first profile.
Data Source
AI summary
An illustrative stent may comprise an elongated tubular member having a first end and a second end and an intermediate region disposed therebetween. The elongated tubular member may include at least one barb attached thereto. The barb may be configured to be tucked under a filament of the stent during delivery of the stent and protrude radially from the stent, when the stent is deployed.