Stent Barb Aperture Design for Migration Resistance
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Solution Overview
Problem
Intraluminal prostheses, such as stents and stent grafts, face challenges in preventing migration due to mechanical and chemical hazards in the body's physiological environment, particularly from pulsatile forces, leading to potential detachment of barbs or hooks from the stent.
Innovation Solution
The design incorporates an elongate strut with a barb having a base and a distal anchor, where the barb base is attached to the strut through an aperture that provides a secure mechanical attachment, reducing stress on the weld or solder joint by spacing it away from the high-stress junction, and using a biocompatible material to minimize corrosion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If traditional attachment methods (soldering, welding, brazing) are used to attach barbs to stent struts, then a strong bond is created, but the attachment is prone to breaking under mechanical and chemical hazards in the intraluminal environment
Solution Approach 1:
The attachment system is divided into multiple components: the barb, the aperture through the strut, and the surrounding tissue engagement structure. This segmentation distributes the mechanical loads across different elements rather than concentrating them at a single welded or soldered joint, reducing the risk of attachment failure under pulsatile forces.
Solution Approach 2:
The aperture in the strut serves as an intermediary structure that mechanically interfaces the barb with the stent framework. Rather than relying solely on chemical bonds (welding/soldering), the aperture provides a physical pathway through which the barb passes and engages with surrounding tissue, distributing stresses away from any single attachment point.
2Stability of the object's composition
If barbs are attached to stent struts to prevent migration, then anchoring stability is improved, but the attachment site becomes a stress concentration point subject to cyclic loading from pulsatile blood flow
Solution Approach 1:
The stent structure exhibits local quality variations: the aperture region is specifically designed to accommodate the barb passage, while other portions of the strut maintain their original structural properties. This localized modification allows the barb to be securely anchored without compromising the overall structural integrity or creating excessive stress concentrations in the strut material.
Solution Approach 2:
The attachment mechanism extends into the radial dimension by having the barb pass through the aperture and engage with surrounding tissue in the radial direction. This three-dimensional anchoring approach distributes forces across multiple spatial dimensions rather than relying solely on a two-dimensional surface attachment, reducing stress concentration at any single point.
Data Source
AI summary
A stent is described and comprises an elongate strut having a first end and a second end, an aperture formed in the strut, and a barb having a base and a distal anchor. The barb base is attached to the strut and the barb extends distally from the base through the aperture. Other devices, systems, and methods are described.