Self-Expanding Nitinol Stent for Heart Valve Anchoring
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Solution Overview
Problem
Current heart valve prostheses for minimally invasive procedures face challenges such as inaccurate deployment, stent displacement, coronary artery ostium obstruction, and bundle branch block due to their inability to adjust post-deployment and inadequate adherence to the native valve annulus, leading to potential life-threatening complications.
Innovation Solution
A self-expanding stent with a concave contour in the inflow section, fabricated from nitinol alloy, that allows for accurate deployment and adjustment, preventing perivalvular leakage and stent displacement, and features a conical tapering design to avoid coronary artery obstruction, enabling secure anchoring and precise control of stent extension within the ventricle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional heart valve prosthesis is deployed, then the valve replacement procedure can be performed, but the stent may displace or fail to adhere properly to the native valve annulus causing perivalvular leakage
Solution Approach 1:
The stent is designed with a concave contour that matches the anatomical curvature of the native valve annulus. This curved geometry enables the stent to conform precisely to the annular structure, improving adherence and preventing perivalvular leakage while maintaining stable anchoring.
Solution Approach 2:
The stent features a conical tapering design with varying radial strength along its length. The inflow section has higher radial strength for secure anchoring in the annulus, while the outflow section has lower radial strength to avoid coronary artery obstruction. This localized variation in mechanical properties optimizes both anchoring stability and safety.
2Reliability
If the stent is extended sufficiently to ensure secure anchoring, then anchoring stability improves, but coronary artery ostium obstruction and bundle branch block may occur
Solution Approach 1:
The stent exhibits spatially varying radial strength along its longitudinal axis. The inflow section possesses high radial strength to ensure secure anchoring in the valve annulus, while the outflow section gradually tapers to low radial strength. This localized differentiation allows the stent to maintain anchoring security without exerting excessive radial force on the coronary arteries, thereby preventing coronary obstruction and bundle branch block.
Solution Approach 2:
The conical tapering geometry creates a smooth transition from the high-strength anchoring zone to the low-strength outflow zone. This curved profile ensures that the stent conforms to the anatomical structure while distributing mechanical forces appropriately, securing anchoring without compromising adjacent vascular structures.
3Ease of manufacture
If the stent uses a uniform radial strength design, then manufacturing is simpler, but it cannot simultaneously achieve secure anchoring and avoid coronary artery obstruction
Solution Approach 1:
The stent is engineered with non-uniform radial strength distributed along its length. The inflow section is designed with high radial strength for secure anchoring in the valve annulus, while the outflow section features gradually decreasing radial strength to minimize risk to coronary arteries. This localized variation in mechanical properties enables the stent to simultaneously achieve both anchoring security and clinical safety.
Solution Approach 2:
The stent structure is divided into distinct functional zones: an inflow section optimized for anchoring with high radial strength, and an outflow section optimized for safety with low radial strength. This segmentation allows each zone to perform its specific function effectively, resolving the conflict between anchoring requirements and coronary protection.
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 stent achieves high deployment accuracy, reduces the risk of complications like bundle branch block and perivalvular leakage, and allows for precise control of stent extension, ensuring secure anchoring and effective valve function.
Implementation Method 1
A self-expanding stent with a concave contour in the inflow section, fabricated from nitinol alloy
Implementation Method 2
The stent has a contracted delivery configuration and an expanded deployed configuration
Data Source
AI summary
A stent (1) used for a heart valve prosthesis and the heart valve prosthesis that includes the stent (1) and is used for heart valve replacement. The stent is configured to support a heart valve (3) and includes, along a longitudinal axis, an inflow section (8), an outflow section (6) and a transition section (7) between the inflow section (8) and the outflow section (6). The stent (1) has a contracted delivery configuration and an expanded deployed configuration. In the expanded deployed configuration, the inflow section (8) defines a concave contour that is complementary to a structure of a native valve annulus. The concave contour enables self-deployment and close adherence of the stent (1), thereby preventing its displacement and perivalvular leakage after implantation.