Adjustable Radial Strength Stent for Easier Neurovascular Deployment
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Solution Overview
Problem
Conventional neurovascular stents are non-compliant, stiff, difficult to navigate, and have predetermined radial strengths that can lead to complications such as in-stent stenosis, thrombosis, and implant migration due to improper sizing and repositioning challenges.
Innovation Solution
An intravascular device with an inner stent and outer stent configuration that allows for adjustable radial strength through fusion of the inner stent to the outer stent using energy application, enabling easy navigation and precise sizing to match target vasculature anatomy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional neurovascular stents are made stiff to provide adequate radial strength, then they can maintain vessel patency, but they become difficult to navigate and reposition
Solution Approach 1:
The stent is divided into multiple segments or struts that can be independently controlled. During navigation, the stent maintains a compressed low-profile state for easy delivery. Upon deployment, the segments expand to provide the necessary radial strength. This segmentation allows the stent to transition between compliant (for navigation) and stiff (for vessel support) states.
Solution Approach 2:
The stent employs dynamic structural elements that can change their mechanical properties during deployment. The stent transitions from a flexible, compliant state during navigation to a rigid, high-radial-strength state after deployment. This dynamic transformation is achieved through mechanisms such as shape memory alloys, self-expanding structures, or balloon-expandable designs that lock into position.
2Ease of manufacture
If conventional stents have predetermined radial strength, then manufacturing is simplified, but improper sizing leads to complications such as in-stent stenosis, thrombosis, and implant migration
Solution Approach 1:
The stent design allows for adjustment of radial strength parameters after deployment. The stent can be expanded to different diameters or have its radial force modified through mechanisms such as adjustable struts, shape memory material transformation, or post-deployment inflation. This enables precise matching to the target vasculature anatomy, eliminating sizing errors and preventing complications like in-stent stenosis and migration.
3Ease of operation
If conventional stents are made compliant to navigate tortuous vasculature, then navigation is improved, but they lack sufficient radial strength to maintain vessel patency
Solution Approach 1:
The stent utilizes dynamic structural elements that transition from a compliant, flexible state during navigation to a rigid, high-radial-strength state after deployment. Shape memory alloys or self-expanding mechanisms enable the stent to conform to tortuous vasculature during delivery, then automatically expand to provide adequate vessel support once positioned.
Solution Approach 2:
The stent is designed with nested structures where inner components are contained within outer components during delivery. The stent can be compressed within a delivery catheter for navigation through tortuous vessels, then expanded outward to provide radial support. This nested design allows the stent to maintain a low-profile compliant state during navigation while achieving high radial strength when deployed.
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 device provides improved deployment success with adjustable radial strength, reducing complications and enhancing compliance to various anatomical shapes and sizes, while allowing in-situ adjustment and repositioning.
Implementation Method 1
the support structure is fused, at a plurality of fusion points, to the lumen of the outer stent by applying energy to the intravascular device
Implementation Method 2
application of an electric current to the at least a portion of the plurality of tethers is configured to: disengage the plurality of tethers from the proximal end and the distal end of the stent, respectively, and fuse a luminal segment of the plurality of tethers, extending through the lumen of the stent, to the stent
Data Source
AI summary
An intravascular device may have a first configuration during deployment and a second configuration after deployment. The first configuration has a first radial strength; and the second configuration has a second radial strength. The first radial strength is less than the second radial strength. A system may include an intravascular device; a wire extending through the intravascular device to expand or contract the intravascular device; a proximal hub coupled to the wire; a distal hub coupled to the wire; and a plurality of tethers extending from an input device and through the intravascular device. At least a portion of the plurality of tethers has electrical conductivity. Application of energy to the at least a portion of the plurality of tethers may disengage the plurality of tethers from the intravascular device and fuse a luminal segment of the plurality of tethers, extending through the intravascular device, to the intravascular device.