Stent Cover Member Shielding Tissue Inflammation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Implantable medical devices, such as stents, often cause tissue inflammation and irritation due to deformation forces in moving body lumens, leading to complications like reduced patency and increased removal difficulty.
Innovation Solution
Designing stents with a cover member that extends over nodes to shield the anatomy from sharp edges, reducing irritation and inflammation, and using materials like metal alloys and polymers for durability and biocompatibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If stents are designed with sharp edges for structural integrity, then mechanical strength is improved, but tissue inflammation and irritation increase
Solution Approach 1:
A polymer coating layer is applied as an intermediary between the metal stent structure and the surrounding tissue. This coating layer has different mechanical properties than the metal, providing a softer interface with tissue while maintaining the structural integrity of the underlying stent framework. The coating acts as a mediator that prevents direct contact between sharp metal edges and tissue, thereby reducing inflammation while preserving mechanical strength.
Solution Approach 2:
The stent is covered with a thin polymer film or coating that conforms to the stent's structure. This flexible shell provides a biocompatible surface that reduces tissue irritation and inflammation. The thin film maintains the stent's mechanical properties while creating a softer external surface that is less harmful to surrounding tissue.
2Strength
If stents are made rigid for structural support, then mechanical support is improved, but ease of removal deteriorates
Solution Approach 1:
The stent is divided into multiple segments or struts that can move relative to each other. This segmentation allows the stent to maintain rigidity when deployed for structural support, while also enabling flexibility for removal. The segmented structure can be compressed or collapsed by applying force to specific segments, facilitating extraction while maintaining overall structural integrity during normal function.
Solution Approach 2:
The stent structure incorporates dynamic elements that allow it to transition between rigid and flexible states. During normal operation, the stent maintains a rigid configuration for mechanical support. During removal, the structure can be dynamically collapsed or compressed by applying radial force, transforming it into a flexible state that facilitates extraction through the delivery catheter.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Implantable medical devices and methods for making and using the same are disclosed. An example implantable medical device may include a stent having a first configuration and a second expanded configuration. The stent may define a plurality of nodes. The stent may have a cover member disposed adjacent the nodes. The cover member may be configured to cover at least some of the nodes when the stent is in the expanded configuration.