Deformable Retention Members for Anti-Migration Self-Expanding Stents

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Solution Overview

Problem

Existing stents used to create anastomosis between anatomical structures face challenges in remaining in place due to natural body movements, particularly when deployed across different organs, leading to stent migration.

Innovation Solution

The use of longitudinally self-expanding implantable medical devices with deformable retention members that can change length in response to applied force, providing enhanced longitudinal expansion to accommodate body movements and prevent migration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a stent is deployed across anatomical structures to create an anastomosis, then fluid communication between structures is established, but the stent migrates due to natural body movements

Engineering Contradiction:

Improvestent position stabilityVSAvoidstent longitudinal rigidity

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The retention members are designed to be deformable rather than rigid, allowing them to dynamically adjust their configuration in response to applied forces from body movements. The members can compress and expand longitudinally while maintaining their anchoring function, providing adaptability to physiological changes without compromising stent position stability

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The retention members utilize shape memory material properties to change their physical parameters (shape, length, configuration) in response to temperature or stress changes. This allows the members to transition between different states - maintaining rigidity for anchoring and becoming more compliant to accommodate body movements, thereby resolving the contradiction between stability and adaptability

Inventive Principle:

Principle #35Parameter changes

2Reliability

If the stent is made rigid to maintain position, then migration is prevented, but the stent cannot accommodate natural body movements

Engineering Contradiction:

Improvestent position stabilityVSAvoidstent flexibility to body movements

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The stent is divided into functionally distinct segments: the elongated body portion and the retention members. The retention members are specifically designed with deformable characteristics to provide flexibility and adaptability, while the main body maintains structural integrity. This segmentation allows different parts of the stent to have different mechanical properties, enabling both position stability and accommodation of body movements

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The retention members are formed from shape memory material, which combines properties of both rigidity and flexibility. This composite material approach allows the members to exhibit rigid behavior under normal conditions for stable anchoring, while transitioning to a more compliant state when subjected to forces from body movements, thus achieving both reliability and adaptability

Inventive Principle:

Principle #40Composite materials

3Adaptability or versatility

If the retention member is made deformable to accommodate body movements, then migration is prevented, but the retention strength may be reduced

Engineering Contradiction:

Improveretention member deformabilityVSAvoidretention strength

Core Design Contradiction:

Adaptability or versatilityVSStrength

Solution Approach 1:

The shape memory material in the retention members allows for parameter changes in response to external stimuli. When subjected to compressive forces from body movements, the members can deform and change their length, yet maintain sufficient retention strength through the material's inherent properties. The material can transition between different structural states, providing both deformability and strength as needed

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 solution effectively maintains stent position over prolonged periods by allowing for increased longitudinal expansion, mitigating migration and ensuring stability across anatomical structures.

Implementation Method 1

the retention member is configured to deform responsive to an application of a force along a longitudinal axis of the implantable medical device

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Implementation Method 2

the retention member, the saddle region, and the elongated body are formed of the same material wherein the material is a shape memory material

Methodology Applied

Scientific EffectShape memory effect: Shape Memory Alloy

Data Source

PatentUS20250352365A1Self-expanding stents with deformable retention members

Publication Date: 2025.11.20 BOSTON SCIENTIFIC SCIMED INC

AI summary

An implantable medical device comprising an elongated body having a first end, a second end, and a lumen extending therebetween, a saddle region defined between the first end and the second end, a retention member at the first end, the second end, or both, wherein the retention member extends substantially traverse to a longitudinal axis of the implantable medical device and is configured to deform responsive to an application of a force along a longitudinal axis of the implantable medical device.