Shape Memory Foam Embolization for EVAR Endoleak Prevention

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Solution Overview

Problem

Existing endovascular aneurysm repair (EVAR) technologies face complications such as endoleaks and graft migration, requiring frequent follow-up and reintervention due to aneurysm growth and rupture risks, with current embolic materials facing issues like device friction, thrombogenicity, and degradation, leading to increased procedural costs and monitoring burdens.

Innovation Solution

The use of polyurethane shape memory polymer (SMP) foams with radiopaque fibers or coils, designed for low friction delivery and volumetric expansion, providing a compliant scaffold for aneurysm embolization, visible under X-ray, and tailored for delayed expansion to prevent endoleaks and promote healing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional embolic materials are used to fill aneurysms, then embolization can be achieved, but device friction increases and thrombogenicity worsens

Engineering Contradiction:

Improveembolization effectivenessVSAvoiddevice friction and thrombogenicity

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent employs shape memory polymer (SMP) foam that changes its physical parameters from a compressed delivery state to an expanded deployed state. The SMP material undergoes phase transition and volumetric expansion after deployment, transforming from a low-friction compressed state suitable for delivery through catheters to a high-volume expanded state that effectively fills the aneurysm sac while minimizing thrombogenicity

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention uses composite SMP foam material that combines the benefits of shape memory effect with foam structure. The composite nature allows the material to maintain low friction during delivery while providing effective embolization upon expansion, resolving the contradiction between delivery feasibility and embolization effectiveness

Inventive Principle:

Principle #40Composite materials

2Reliability

If frequent follow-up and reintervention are performed to address endoleaks and graft migration, then aneurysm rupture risk is reduced, but healthcare costs and monitoring burden increase

Engineering Contradiction:

Improveaneurysm rupture preventionVSAvoidfollow-up frequency and procedural time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The SMP foam is deployed prophylactically at the time of EVAR to fill the aneurysm sac and prevent endoleak formation before it occurs. This preliminary embolization action eliminates the need for subsequent follow-up interventions to treat endoleaks, reducing both the frequency of monitoring and the burden of reintervention while maintaining aneurysm rupture prevention

Inventive Principle:

Principle #10Preliminary action

3Reliability

If embolic materials are deployed to occlude endoleaks, then blood flow outside stent graft is reduced, but device complexity and procedural cost increase

Engineering Contradiction:

Improveendoleak occlusionVSAvoidmultiple devices and procedural steps

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The SMP foam serves multiple functions: it acts as both the delivery catheter component and the embolic material, and it provides both structural support and volumetric filling. This multi-functionality eliminates the need for separate embolic devices and materials, reducing device complexity and procedural cost while achieving effective endoleak occlusion

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 SMP foams effectively prevent endoleaks, reduce the need for long-term surveillance, and enhance the durability of EVAR by promoting thrombosis and connective tissue infiltration, thereby reducing secondary interventions and healthcare costs.

Implementation Method 1

polyurethane shape memory polymer (SMP) foams with radiopaque fibers or coils, designed for low friction delivery and volumetric expansion

Methodology Applied

Scientific EffectShape memory polymer expansion: Shape Memory Polymer

Implementation Method 2

radiopaque fibers or coils, visible under X-ray

Methodology Applied

Scientific EffectX-ray detection: X-Ray

Data Source

PatentEP3595581B1Vascular prosthesis for leak prevention during endovascular aneurysm repair

Publication Date: 2026.02.25 SHAPE MEMORY MEDICAL INC

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AI summary

An embodiment includes a process for treating an abdominal aortic aneurysm (AAA) endoleak with a shape memory polymer (SMP) foam device. First, a bifurcated stent graft is placed within the aneurysm while a micro guidewire is positioned within the aneurysm for future catheter access. Second, after placing the iliac graft extension, a catheter is introduced over wire to deliver embolic foams. Third, embolic foams expand and conform to the aneurysm wall. Fourth, embolic foams create a stable thrombus to prevent endoleak formation by isolating peripheral vessels from the aneurysm volume.