Multi-Spiral Self-Expanding Stent for Aortic Conformability

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Solution Overview

Problem

Existing stents are unable to conform to the changing diameters and curvatures of the aorta, and lack the necessary radial resistive force for treating conditions like aortic dissections, leading to varying degrees of collapse in clinical use.

Innovation Solution

A multi-spiral, self-expanding stent constructed from strands that can change length and diameter to accommodate varying aortic shapes, with a graft collar for reinforcement, made from materials like stainless steel, titanium, or polymeric materials, allowing for minimal radial resistive force and maximum outward chronic force.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If prior art stents are designed to fit vessels of uniform diameter and length, then manufacturing and deployment are simplified, but the stents cannot conform to the changing diameters and curvatures of the aorta

Engineering Contradiction:

Improveconformability to varying aortic diameters and curvaturesVSAvoidstent structure complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The stent is divided into multiple independent spiral strands (typically 3-6 strands) that can move and deform independently. Each strand consists of a continuous material formed into a spiral configuration, allowing the stent to segment and adapt to varying aortic geometries while maintaining overall structural integrity

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The stent employs dynamic spiral strands that can change their configuration in response to external forces. The strands are designed with specific pitch, diameter, and spacing parameters that allow them to dynamically adjust to the changing diameters and curvatures of the aorta during deployment and in-vivo operation

Inventive Principle:

Principle #15Dynamics

2Force

If prior art stents are made with standard structures, then manufacturing is easier, but they lack the required radial resistive force for treating aortic dissections and collapse in clinical use

Engineering Contradiction:

Improveradial resistive forceVSAvoidstent fabrication complexity

Core Design Contradiction:

ForceVSEase of manufacture

Solution Approach 1:

The radial resistive force is optimized by carefully controlling geometric parameters of the spiral strands including pitch (distance between adjacent turns), diameter of the spiral, thickness of the strand material, and spacing between adjacent strands. These parameters are adjusted during manufacturing to achieve the required force characteristics for aortic dissection treatment

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The stent may be constructed from composite materials or coated materials that combine the structural integrity needed for radial support with surface properties that facilitate endothelialization and reduce thrombogenicity. The strands can be made from stainless steel, nitinol, or other biocompatible materials with appropriate mechanical properties

Inventive Principle:

Principle #40Composite materials

3Strength

If the stent is made from continuous material strands, then structural integrity is improved, but the ability to change length and diameter to accommodate varying aortic shapes is reduced

Engineering Contradiction:

Improvestructural integrityVSAvoidability to change length and diameter

Core Design Contradiction:

StrengthVSAdaptability or versatility

Solution Approach 1:

The continuous material is segmented into multiple independent spiral strands rather than forming a single rigid structure. This segmentation allows each strand to deform independently while maintaining the structural integrity provided by the continuous material, enabling the stent to adapt to varying aortic shapes

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The spiral strands are constructed with flexible characteristics that allow them to bend and conform to the aortic curvature. The continuous material is formed into thin-walled spiral structures that maintain strength while providing the flexibility needed to accommodate changing aortic geometries

Inventive Principle:

Principle #30Flexible shells and thin films

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 adjusts to accommodate different aortic diameters and lengths, providing sufficient radial support to prevent collapse and maintain patency, as demonstrated by its ability to change shape and diameter to fit varying aortic anatomies and withstand compressive forces.

Implementation Method 1

exert a minimal radial resistive force of at least 1N despite changing its length and diameter; exert a maximum outward chronic force of 7N despite changing its length and diameter

Methodology Applied

Scientific EffectRadial resistive force: Force

Implementation Method 2

configured to change its length and diameter to adjust itself to the diameter of a hollow tube

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Data Source

PatentUS12167958B2Multi-spiral self-expanding stent and methods of making and using the same

Publication Date: 2024.12.17 ASCYRUS MEDICAL LLC

AI summary

A multi-spiral, self-expanding stent is constructed from superposed individual spiral strands. Each spiral strand comprises a terminal bend that separates the strand into a first portion and a second portion. Particularly, the first portion of each strand bends in a first spiral direction to the terminal bend, and the second portion bends in the opposite direction after the terminal bend. Advantageously, the disclosed stent is able to change its shape, diameter, and length to accommodate the corresponding shape, diameter, and length of patient's diseased vessel.