Braided-Twisted Stent Structure to Prevent Deployment Elongation

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Solution Overview

Problem

Existing stents and implants experience significant elongation during deployment, leading to reduced mechanical strength and potential disconnection at bifurcations due to insufficient radial expansion, which compromises their mechanical properties and connection reliability.

Innovation Solution

A tubular structure with a combination of braided and twisted longitudinal sectors, featuring individual twists distributed over the entire perimeter, ensures minimal or zero elongation under compressive forces, maintaining mechanical integrity and connection reliability through foldable peripheral ends and retaining beads.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If existing stents are compressed and deployed, then they can be placed in the vessel, but they elongate during deployment resulting in reduced mechanical strength

Engineering Contradiction:

ImprovedeployabilityVSAvoidmechanical strength

Core Design Contradiction:

Ease of operationVSStrength

Solution Approach 1:

The stent is divided into multiple longitudinal sectors (first, second, third sectors) with different structural characteristics. The first and third sectors have braided wire structures providing radial strength, while the second sector has twisted wire structure providing flexibility and controlling elongation. This segmentation allows different parts of the stent to perform different functions during deployment and in the deployed state.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different longitudinal sectors of the stent are given different local qualities through varying wire configurations. The braided sectors provide high radial strength and resistance to crushing, while the twisted sector provides flexibility and controlled elongation characteristics. This local differentiation resolves the contradiction by ensuring that strength-critical areas maintain strength while other areas accommodate deployment requirements.

Inventive Principle:

Principle #3Local quality

2Ease of operation

If the implant is compressed for endoluminal deployment, then minimally invasive placement is achieved, but the connecting elements tend to open creating mechanical play

Engineering Contradiction:

Improveminimally invasive placementVSAvoidconnection reliability

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The connecting elements (retaining ridges and retaining grooves) are pre-configured in specific geometries before deployment. The retaining ridges on the branch stent are designed to engage with corresponding grooves on the main stent at predetermined positions. This preliminary configuration ensures that when compression forces are applied during deployment, the connecting elements maintain their engagement without opening, preventing mechanical play and ensuring reliable connection.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The design of the connecting elements incorporates features that preemptively counteract the opening tendency under compression. The geometric configuration of retaining ridges and grooves creates mechanical interlocking that resists the opening force generated during compression and deployment, thereby maintaining connection reliability throughout the deployment process.

Inventive Principle:

Principle #9Preliminary anti-action

3Ease of operation

If the implant elongates during deployment, then it can be housed in the launcher, but the diameter is reduced altering mechanical characteristics

Engineering Contradiction:

Improvelauncher compatibilityVSAvoiddiameter

Core Design Contradiction:

Ease of operationVSShape

Solution Approach 1:

The stent is designed with dynamic structural characteristics that allow it to change shape during deployment. The twisted wire sector in the middle provides controlled flexibility and elongation during the deployment process, enabling the stent to be housed in the launcher and deployed through the vessel. Once deployed, the braided wire sectors provide structural support to maintain the correct diameter and mechanical characteristics.

Inventive Principle:

Principle #15Dynamics

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 implant maintains its mechanical properties and connection reliability under compressive forces, preventing elongation and ensuring precise positioning and reliable attachment to other implants, while being compatible with minimally invasive deployment techniques.

Implementation Method 1

the tubular structure comprises a combination of braided and twisted longitudinal sectors... ensures minimal or zero elongation under compressive forces, maintaining mechanical integrity

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentEP3716903B1Optimised structure for an expandable implant of the stent or endoprosthesis type

Publication Date: 2025.12.31 ID NEST MEDICAL

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AI summary

The invention concerns an implant (1) comprising an optimised structure for implantation in a canal or in a cavity of a living being, comprising a tubular structure (2) extending along a longitudinal axis (L), said structure (2) comprising at least one braided longitudinal sector (3) of metal wires (4) and open longitudinal ends, characterised in that the tubular structure (2) comprises a braided longitudinal sector (3) at each longitudinal end and at least one twisted longitudinal sector (5, 7), produced with said metal wires (4) in order to form, continuously, said tubular structure (2).