Elastic Annuloplasty Ring With Variable Stiffness Regions
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Solution Overview
Problem
Existing annuloplasty rings are rigid and non-conformable, making it difficult to remove them without damaging surrounding tissue, and they often prevent the proper placement of prosthetic valves due to mismatched shapes and sizes.
Innovation Solution
An annuloplasty ring made from an elastic material with regions of varying elasticity and strategically placed stiffeners to maintain shape and prevent paravalvular leakage, allowing for the reception of a prosthetic valve without excision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a rigid annuloplasty ring is used to treat regurgitation, then coaptation is reestablished, but the ring cannot be removed without damaging surrounding tissue and prevents prosthetic valve placement
Solution Approach 1:
The annuloplasty ring transitions from a rigid structure to a dynamic, flexible structure capable of changing its state. The ring can be in a compressed configuration for initial implantation and treatment of regurgitation, then later expanded or modified to accommodate prosthetic valve placement, allowing it to adapt to different functional requirements over time
Solution Approach 2:
The physical parameters of the annuloplasty ring are made changeable. The ring's stiffness, shape, and dimensional characteristics can be modified after implantation to enable prosthetic valve placement. This may involve changing the ring's structural properties or geometric configuration to create suitable space and support for the prosthetic valve
2Reliability
If a rigid annuloplasty ring is used to reduce valve diameter, then regurgitant flow is reduced, but the ring distorts prosthetic replacement valves and causes regurgitation
Solution Approach 1:
The annuloplasty ring is constructed as a flexible structure rather than a rigid one. This flexibility allows the ring to conform to the shape of prosthetic replacement valves without causing distortion. The flexible material can adapt to the prosthetic valve's geometry while maintaining the necessary support to prevent regurgitation
Solution Approach 2:
Different portions of the annuloplasty ring may have different mechanical properties to optimize local functions. Certain segments may be more flexible to accommodate prosthetic valve contours, while other segments maintain sufficient stiffness to provide structural support and prevent regurgitant flow
3Reliability
If a D-shaped annuloplasty ring is used to match native valve annulus, then coaptation is improved, but prosthetic valve placement is complicated due to shape mismatch
Solution Approach 1:
The annuloplasty ring's shape is made dynamic rather than fixed. It can transition between a D-shaped configuration that matches the native valve annulus for optimal coaptation, and a more circular or expanded configuration that facilitates easy placement of circular prosthetic valves. This shape adaptability resolves the conflict between optimizing native valve function and enabling prosthetic valve implantation
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 elastic annuloplasty ring effectively treats diseased heart valves by restoring coaptation and reducing regurgitation, while also providing a platform for prosthetic valve placement without the need for excision, reducing surgical complexity and risk.
Implementation Method 1
an elongated core including a first region and a second region, wherein the first region is more stretchable than the second region and is adapted for positioning at commissures of a target native heart valve, the first region being made solely from an elastic material; wherein the elongated core is stretchable from a resting state to a stretched state to receive the replacement heart valve
Implementation Method 2
wherein the first region is adapted to impart a squeezing force on the replacement heart valve so as to prevent paravalvular leakage
Data Source
AI summary
An annuloplasty ring includes an elastic elongated core having first regions and second regions, wherein the first regions are more stretchable than the second regions and are adapted for positioning at the commissures of a target native heart valve. The first regions and the second regions may enable the annuloplasty ring to both re-establish coaptation of the leaflets of a diseased native heart valve and establish a seal around a prosthetic replacement heart to prevent paravalvular leakage after a “Valve In Ring Procedure”.