Stent Flexible Web Structure to Minimize Luminal Interference
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Solution Overview
Problem
Existing stents with metallic elements and flexible polymeric connecting elements can protrude into the luminal space, causing clinical complications such as stenosis and altered blood hemodynamics due to insufficient radial force, porosity, and flexibility.
Innovation Solution
The development of an endoprosthesis with flexible connecting elements that fold between the inner and outer circumference when compacted, providing stability and minimizing luminal interference, featuring a section modulus ratio greater than 0.2 and tailored cross-sectional geometry to optimize hemodynamics and deployment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If flexible polymeric connecting elements are used between adjacent metallic stent elements, then flexibility and radial force are improved, but the connecting elements protrude into the luminal space causing stenosis and altered blood hemodynamics
Solution Approach 1:
The polymeric connecting elements are designed to nest within the metallic stent structure when the stent is in its compacted delivery state. The connecting elements are positioned within the circular opening defined by adjacent metallic stent elements, allowing the stent to be delivered through a catheter in a compact configuration. Upon deployment, the connecting elements extend to provide flexibility and radial force while remaining within the luminal space boundaries.
Solution Approach 2:
The connecting elements are designed with dynamic behavior that allows them to change configuration based on the stent's operational state. In the compacted state, the connecting elements are folded or positioned to minimize luminal interference. Upon expansion, they dynamically extend to provide the necessary mechanical support and flexibility, adapting their configuration to the deployed state requirements.
2Ease of operation
If the stent is compacted to a small diameter for catheter transport, then ease of delivery is improved, but the connecting elements may protrude and interfere with luminal flow
Solution Approach 1:
During the delivery phase, the polymeric connecting elements are nested within the metallic stent structure, allowing the entire stent assembly to be compacted to a small diameter that can pass through a catheter. The connecting elements are positioned within the circular opening formed by adjacent metallic elements, creating a compact configuration that minimizes the overall stent diameter for easy delivery through the catheter.
Solution Approach 2:
The stent and connecting elements are pre-configured in a compacted state suitable for delivery through the catheter. The connecting elements are positioned and oriented in advance to ensure they remain within the luminal space boundaries during delivery, preventing interference with blood flow or vessel walls during the transport phase.
3Area of stationary object
If polymeric elements are added to reduce open space between metallic stent elements, then surface area coverage is improved, but device complexity increases
Solution Approach 1:
The polymeric connecting elements are merged with the metallic stent elements to form an integrated stent-graft structure. The connecting elements are continuously attached to the metallic stent elements, creating a unified device where the polymeric material fills the open spaces between metallic elements and provides both structural support and surface area coverage in a single integrated configuration.
Solution Approach 2:
The stent device uses composite construction combining metallic stent elements with polymeric connecting elements. The metallic elements provide structural strength and framework, while the polymeric elements provide flexibility, surface area coverage, and sealing. This composite approach allows each material to contribute its advantageous properties to the overall device performance.
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 solution enhances clinical outcomes by reducing luminal interference, improving blood flow, and providing controlled deployment, while maintaining radial force and porosity, thus minimizing complications like stenosis and thrombosis.
Implementation Method 1
the flexible connecting elements are biased to fold substantially between the inner circumference and the outer circumference when the endoprosthesis is compacted
Implementation Method 2
the flexible connecting elements have a section modulus Mr in a direction aligned with the radius of the endoprosthesis and a section modulus Mp aligned in a direction perpendicular to Mr; and wherein Mr/Mp>0.2
Data Source
AI summary
A stent and method of making incorporating flexible, preferably polymeric, connecting elements into the stent wherein these elements connect element(s) across an intervening space. The polymeric connecting elements are designed to fold within the space between the outer diameter of the stent and the inner diameter of the stent.