Mitral Valve Tether Attachment for LVOT Flow
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Solution Overview
Problem
Collapsible and expandable prosthetic heart valves face challenges in anchoring within the native mitral valve annulus, leading to potential paravalvular leakage and obstruction of blood flow to the Left Ventricular Outflow Tract due to insufficient radial force or migration of the valve.
Innovation Solution
A low-profile collapsible and expandable prosthetic heart valve design featuring an expandable stent with a tether system that secures an apical pad outside the heart, minimizing ventricular extension and using a combination of inner and outer stents to anchor the valve within the native mitral valve annulus without obstructing blood flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a tether is added to anchor the prosthetic heart valve, then anchoring stability is improved, but the valve extends into the ventricle obstructing blood flow
Solution Approach 1:
The tether connector is repositioned from the ventricular side to the atrial side of the valve, changing the spatial dimension of tether attachment. This allows the tether to be routed through the valve body and exit at the atrial end, preventing ventricular extension while maintaining anchoring function through the apical pad secured to the ventricular wall from the atrial side
2Reliability
If radial force is increased to anchor the valve, then anchoring stability is improved, but heart tissue damage occurs
Solution Approach 1:
The anchoring function is segmented into two independent mechanisms: (1) moderate radial force from the expanded stent providing initial anchoring, and (2) the tether system providing additional anchoring stability. This segmentation allows reduction of radial force to safe levels while maintaining overall anchoring stability through the combined action of both mechanisms
Solution Approach 2:
The tether acts as an intermediary element that transfers anchoring force from the ventricular wall (via apical pad) to the valve body, providing additional anchoring stability without requiring high radial force from the stent. This intermediary mechanism distributes the anchoring load and prevents direct excessive force on the heart tissue
3Object-affected harmful factors
If radial force is reduced to prevent tissue damage, then heart tissue damage is prevented, but valve migration occurs
Solution Approach 1:
The anchoring function is segmented into two independent mechanisms: (1) moderate radial force from the expanded stent providing initial anchoring, and (2) the tether system providing additional anchoring stability. This segmentation allows reduction of radial force to safe levels while maintaining overall anchoring stability through the combined action of both mechanisms
Solution Approach 2:
The solution merges two anchoring mechanisms (stent radial force and tether system) into a unified anchoring solution. The stent provides baseline anchoring with reduced radial force to prevent tissue damage, while the tether system supplements this to prevent valve migration, achieving both tissue protection and anchoring stability simultaneously
Data Source
AI summary
A prosthetic mitral valve with improved blood flow to the left ventricular outflow tract. The prosthetic mitral valve includes an expandable outer stent having an atrial end and a ventricular end, and an expandable inner stent attached to and at least partially positioned within the outer stent. The inner stent has an inflow end, an outflow end and a tether connector securing a tether. A valve assembly including a cuff and a plurality of leaflets may be disposed within the inner stent. The tether connector is positioned at the inflow end of the inner stent so as to shorten the overall length of the prosthetic valve.