Braided Wire Frame Anchoring for Transcatheter Heart Valves
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Solution Overview
Problem
Conventional collapsible prosthetic heart valves face challenges in anchoring within the native valve annulus due to inconsistent radial force, leading to potential tissue damage, valve displacement, and paravalvular leakage, especially in areas with uneven calcification or lack of plaque, such as the mitral valve annulus.
Innovation Solution
A collapsible and expandable prosthetic heart valve system featuring a stent and valve assembly with a braided wire frame that can be deployed via a catheter, providing adjustable radial force and anchoring features like flanges and scalloped portions to secure the valve within the native annulus, reducing the risk of leakage and displacement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional collapsible prosthetic heart valves are deployed, then the valve can be delivered less invasively via catheter, but the anchoring within the native valve annulus is inconsistent leading to tissue damage, valve displacement, and paravalvular leakage
Solution Approach 1:
The frame incorporates varying structures at different locations: compression resistance features at the first and second ends to prevent end collapse, and radial strength features in the body portion to maintain radial expansion force against the annulus. This localized differentiation addresses anchoring consistency while maintaining minimally invasive delivery.
Solution Approach 2:
The frame is designed with dynamic characteristics including the ability to expand and contract radially, with features that provide compression resistance in the longitudinal direction while maintaining radial flexibility. This allows the frame to adapt to varying annulus conditions and maintain reliable anchoring.
2Stability of the object's composition
If the stent exerts radial force to anchor the valve, then the valve remains positioned, but inconsistent radial force causes tissue damage and paravalvular leakage
Solution Approach 1:
The frame modifies the radial force parameter through its structural features: the compression resistance features prevent excessive longitudinal compression that would concentrate radial force, while the radial strength features distribute the radial expansion force more evenly across the annulus contact surface, reducing localized tissue damage.
Solution Approach 2:
The frame is segmented into distinct functional zones: end portions with compression resistance features and a body portion with radial strength features. This segmentation allows independent optimization of force distribution characteristics to prevent both valve displacement and tissue damage.
3Ease of operation
If the valve is made collapsible for catheter delivery, then the procedure is less invasive, but the frame may collapse longitudinally during delivery compromising valve function
Solution Approach 1:
The frame incorporates compression resistance features specifically at the first and second ends to prevent longitudinal collapse during delivery, while the body portion maintains radial strength for anchoring. This localized structural differentiation preserves both collapsibility for delivery and structural integrity for function.
4Strength
If the frame is made more rigid to prevent collapse, then structural integrity is improved, but the ability to adapt to native annulus irregularities is reduced
Solution Approach 1:
The frame utilizes shape memory alloy material properties to dynamically change its mechanical parameters: remaining flexible during delivery to adapt to annulus irregularities, then transitioning to a more rigid state after deployment to maintain structural integrity and prevent collapse.
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 system effectively anchors the prosthetic heart valve, reduces paravalvular leakage, and ensures stable positioning by adapting to the native valve annulus irregularities, enhancing cardiac efficiency and minimizing the need for invasive surgeries.
Implementation Method 1
a collapsible and expandable frame (300S) formed of braided wires (305)... the frame is configured for partial deployment, resheathing and redeployment from the delivery device
Data Source
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AI summary
A prosthetic heart valve (200) having an inflow end (210) and an outflow end (212) includes a collapsible and expandable stent (250). A collapsible and expandable valve assembly (260) is disposed within the stent and includes a plurality of leaflets (262). A collapsible and expandable frame formed of braided wires (305) has a body portion and a lumen extending through the body portion for receiving the stent and the valve assembly. The frame may include features for holding the prosthetic heart valve in place in a patient.