Self-Expanding Vascular Plug with Helical Shape Memory for Large Vessel Occlusion
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Solution Overview
Problem
Current vascular occlusion devices are limited in their ability to effectively occlude vessels larger than 5 mm via a microcatheter, often requiring larger catheters that can cause technical failures and vessel injury, and struggle with simultaneous occlusion of both upstream and downstream vascular segments, particularly in high-flow situations and complex anatomies.
Innovation Solution
A self-expanding tubular vascular plug with a coiled or spiraling shape memory element that can assume a larger secondary helical configuration, allowing for occlusion of vessels up to 9 mm in diameter through a microcatheter, and enabling simultaneous occlusion of both upstream and downstream segments by forming a double helix configuration or using interlocking devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If larger 4 French and 5 French diagnostic catheters are used to occlude vessels larger than 5 mm, then vessel occlusion capability is improved, but navigability through tortuous anatomy deteriorates and risk of technical failures and vessel injury increases
Solution Approach 1:
The patent employs a nested structure where a microcatheter (smaller catheter) is used to deliver a vascular plug that expands to occlude larger vessels. The plug is delivered in a compressed state through the microcatheter and then expands in situ to achieve occlusion of vessels up to 9 mm, allowing navigation through tortuous anatomy with a flexible microcatheter while achieving the occlusion capability of larger catheters.
Solution Approach 2:
The vascular plug transitions from a compressed delivery configuration to an expanded occlusion configuration. The plug is delivered in a compacted state through the microcatheter and then expands radially to engage the vessel wall and occlude blood flow, providing dynamic adaptability to match vessel size and anatomy.
2Quantity of substance
If detachable balloons are used for vessel occlusion, then occlusion capability is improved, but device stability deteriorates due to premature detachment and deflation over time
Solution Approach 1:
The vascular plug is constructed with multiple segments or layers including a scaffold structure with struts and cross-members that provide mechanical stability. This segmented construction prevents premature detachment and maintains structural integrity over time, addressing the reliability issues of single-component balloon devices.
Solution Approach 2:
The plug combines multiple materials including shape memory alloy (Nitinol) for the scaffold, fabric layers for structural support, and thrombogenic coating materials. This composite construction provides both immediate mechanical occlusion and long-term stability through material properties that resist degradation and detachment.
3Quantity of substance
If coils are used for vessel occlusion, then occlusion capability is improved, but procedural efficiency deteriorates due to requiring multiple coils and increased procedure time
Solution Approach 1:
The vascular plug integrates multiple functional elements into a single device: a self-expanding scaffold for mechanical occlusion, thrombogenic coating for clot formation, and radiopaque markers for visualization. This combines the functions of multiple coils into one deployable unit, reducing procedure time and improving efficiency.
4Speed
If uncovered plugs are used for rapid occlusion, then occlusion speed is improved, but long-term occlusion reliability deteriorates particularly in high flow situations
Solution Approach 1:
The plug surface is coated with thrombogenic materials that change the surface properties to promote clot formation. The coating materials (fibrin, collagen, albumin) alter the biochemical parameters of the device surface, enabling rapid thrombosis while the underlying scaffold provides long-term structural support for sustained occlusion reliability.
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
Enables effective occlusion of larger vessels and complex anatomies with reduced risk of migration and vessel injury, providing stable long-term occlusion and improved navigability through tortuous anatomy, while allowing for precise control of thrombosis and flow management.
Implementation Method 1
The additional shape memory element of wire has a coiled base (unstressed) configuration and exerts sufficiently strong shape-memory force to twist the tubular structure or plug into the spiraling or helical configuration
Data Source
AI summary
A vascular plug comprises a superstructure expandable from a collapsed percutaneous insertion configuration to an expanded deployment or use configuration. The superstructure is comprised of both primary and secondary three-dimensional shapes allowing for the occlusion of a wide range of vessel sizes from small to large through a disproportionately small delivery catheter. The plug includes a shape memory element for the generation of radial force and the creation of the larger secondary three-dimensional twisting or helical superstructure as is needed for target vessel occlusion.