Prosthetic Mitral Valve Anchor Arms and Flange Sealing
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Solution Overview
Problem
Prosthetic heart valves face challenges such as inadequate anchoring, perivalvular leakage, and difficulty in accommodating irregular mitral valve annuli, which can lead to valve migration and obstruction of the left ventricular outflow tract, requiring improved securement and sealing mechanisms.
Innovation Solution
The design incorporates a stent with anchor arms and a flange structure, where anchor arms are shaped to hook under native leaflets and a flange with a braided mesh provides enhanced anchoring and sealing, preventing migration and leakage, and is configured to accommodate various annuli sizes without obstructing blood flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a prosthetic valve is made collapsible for minimally invasive delivery, then the invasiveness of the procedure is reduced, but the anchoring stability and sealing performance may be compromised
Solution Approach 1:
The stent is divided into multiple functional segments: a delivery stent for minimally invasive delivery, and separate anchor arms that can be deployed independently to engage with the mitral valve annulus. This segmentation allows the valve to be delivered through a catheter while maintaining reliable anchoring through the separate anchor arm mechanism.
Solution Approach 2:
The anchor arms are pre-configured in a compressed state within the delivery catheter, ready for deployment. Upon reaching the target site, the anchor arms are released and automatically engage with the annulus, establishing secure anchoring before the valve is fully deployed. This preliminary preparation ensures anchoring stability is achieved immediately upon deployment.
2Reliability
If anchor arms are added to improve anchoring, then anchoring stability is improved, but the device complexity increases
Solution Approach 1:
The anchor arms are integrated with the delivery stent as a unified structure. The anchor arms are formed as extensions or attachments to the stent framework, combining the delivery function and anchoring function into a single integrated device rather than separate components.
Solution Approach 2:
The anchor arms are designed to automatically engage with the mitral valve annulus upon deployment without requiring additional manual manipulation or separate anchoring steps. The mechanical geometry of the anchor arms allows them to self-position and self-engage with the annular tissue, reducing the need for complex deployment procedures.
3Reliability
If a flange structure is added for sealing, then perivalvular leakage is reduced, but the risk of obstructing the left ventricular outflow tract increases
Solution Approach 1:
The flange is designed with non-uniform geometry, featuring a seal portion that extends radially outward to contact the annulus for sealing, while the body portion maintains a smaller profile. This local differentiation provides enhanced sealing at the critical annular interface while preserving adequate blood flow through the left ventricular outflow tract.
Solution Approach 2:
The flange structure utilizes the radial dimension to provide sealing contact with the annulus, extending outward perpendicular to the flow direction. This radial extension provides sealing without requiring axial protrusion that would obstruct the left ventricular outflow tract, effectively using a different spatial dimension to resolve the contradiction.
4Adaptability or versatility
If the valve is designed to accommodate irregular annuli, then adaptability is improved, but manufacturing precision requirements increase
Solution Approach 1:
The stent and flange are designed with flexible, dynamic geometry that can adapt to irregular annular shapes. The stent comprises multiple expandable cells that can deform to match the contours of irregular annuli, and the flange's seal portion can conform to non-circular annular geometries, providing adaptability without requiring multiple precisely manufactured valve sizes.
Data Source
Figure 1
Figure 2
Figure 3A
AI summary
A prosthetic heart valve having an inflow end and an outflow end includes a stent having a collapsed condition, an expanded condition, and cells arranged in circumferential rows. The stent has an anterior side configured to be disposed adjacent an anterior native valve leaflet and a posterior side configured to be disposed adjacent a posterior native valve leaflet. A valve assembly having a plurality of leaflets is disposed within the stent and a flange is disposed about the stent. The flange includes a flared portion adjacent the inflow end and a body portion extending from the flared portion to the outflow end, the flange extending between a first set of attachment points adjacent the inflow end, and a second set of attachment points adjacent the outflow end.