Reduced Wire Profile Stent Design for Tissue Perforation Prevention

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Solution Overview

Problem

Conventional stents with rigid flanges or flares can cause tissue perforation during peristalsis, leading to painful complications and potential death due to excessive radial force on the vessel wall.

Innovation Solution

A stent design with reduced wire profiles, achieved through electropolishing or other profile reduction methods, which decreases the diameter of specific portions to reduce radial force and flexibility, thereby minimizing tissue trauma while maintaining adequate radial force for patency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If flanges or flares are made rigid to prevent stent migration, then stent stability is improved, but tissue damage occurs due to excessive radial force

Engineering Contradiction:
Improvestent stabilityVSAvoidtissue damage
Core Design Contradiction:
Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The stent incorporates different wire profiles at different locations: a larger wire profile in the central portion for radial strength and patency maintenance, and a reduced wire profile at the ends for flexibility and reduced tissue trauma. This local differentiation allows the stent to simultaneously achieve stability through radial force while minimizing harmful effects on surrounding tissue.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The stent is divided into distinct segments with different structural properties: a central tube portion with larger wire profile and end portions with reduced wire profile. This segmentation allows each portion to perform its specific function - the central portion provides structural support and radial force, while the end portions provide flexibility and adaptability to tissue movement, resolving the contradiction between stability and tissue damage.

Inventive Principle:
Principle #1Segmentation

2Object-affected harmful factors

If wire diameter is reduced to decrease radial force, then tissue trauma is minimized, but stent strength is compromised

Engineering Contradiction:
Improvetissue traumaVSAvoidstent strength
Core Design Contradiction:
Object-affected harmful factorsVSStrength

Solution Approach 1:

Different wire profiles are applied to different portions of the stent based on local requirements. The reduced wire profile at the ends minimizes tissue trauma where flexibility is needed, while the larger wire profile in the central portion maintains stent strength for patency. This localized property assignment resolves the contradiction between reducing tissue trauma and maintaining overall stent strength.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The wire profile parameter (diameter) is changed along the length of the stent to optimize performance. By varying the wire diameter from larger in the center to smaller at the ends, the stent achieves both sufficient strength for maintaining patency and reduced trauma to surrounding tissues, resolving the contradiction between these two requirements.

Inventive Principle:
Principle #35Parameter changes

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 reduced wire profile stent design decreases the incidence of tissue perforation and hyperplasia by adapting to the tissue environment, ensuring effective vessel patency without causing damage, and can be tailored to exert appropriate radial force.

Implementation Method 1

achieved through electropolishing or other profile reduction methods

Methodology Applied
Scientific EffectElectropolishing: Electrolysis

Data Source

PatentEP2763629B1Reduced wire profile stent
Publication Date: 2019.02.20 COOK MEDICAL TECHNOLOGIES LLC
  • EP2763629B1 patent drawingFigure 1
  • EP2763629B1 patent drawingFigure 1A~1D
  • EP2763629B1 patent drawingFigure 2

AI summary

Methods and apparatuses of stents with likely reduced rates of tissue perforation are provided. Some embodiments include reducing the profile of a portion (100a, 100b) of the stent (100) using a wire profile reduction electropolishing bath and/or other wire profile reduction means.