Coiled Wire Sealing Ring for Transcatheter Heart Valve Paravalvular Leak Mitigation
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Solution Overview
Problem
Collapsible prosthetic heart valves often experience paravalvular leaks due to imperfect sealing between the valve and cardiac tissue, leading to inefficiencies and complications during heart valve replacement procedures.
Innovation Solution
A collapsible and expandable prosthetic heart valve design featuring a stent with a sealing ring that includes a tube formed from a coiled wire, optionally with a covering and fillers, axially offset from the leaflet belly to minimize the crimp profile and enhance sealing, thereby reducing paravalvular leaks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sealing ring is added to prevent paravalvular leaks, then sealing performance is improved, but device complexity increases
Solution Approach 1:
The sealing ring is integrated within the valve assembly structure, with the tube nested around the stent frame and the covering nested around the tube. This nested configuration allows multiple sealing components to occupy the same spatial envelope, preventing paravalvular leaks without proportionally increasing the overall device footprint or structural complexity.
Solution Approach 2:
The sealing ring employs a flexible tube made from coiled wire and a flexible covering that can conform to the irregularities of the native valve annulus. This flexibility allows the sealing surface to adapt to anatomical variations, improving sealing performance while keeping the structure relatively simple and compliant with the delivery system constraints.
2Reliability
If the sealing ring is positioned to optimize sealing, then sealing effectiveness is improved, but crimp profile increases
Solution Approach 1:
The sealing ring is positioned axially offset from the leaflet belly in the axial dimension, allowing the sealing surface to extend into the sub-annular space. This dimensional arrangement optimizes sealing effectiveness by placing the sealing surface where it can best contact the native annulus, while the coiled wire construction allows the structure to compress to a smaller radial profile during crimping for delivery.
Solution Approach 2:
The coiled wire construction of the tube allows the sealing ring to change its physical parameters between deployed and crimped states. When deployed, the coil expands to provide a large sealing surface area for effective sealing. When crimped for delivery, the coil compresses to a smaller profile, enabling passage through the delivery catheter without requiring an excessively large delivery system.
3Ease of operation
If a coiled wire tube is used for the sealing ring, then collapsibility is improved, but manufacturing precision requirements increase
Solution Approach 1:
The coiled wire tube provides dynamic collapsibility, allowing the sealing ring to transition between expanded and compressed states. The coil structure inherently provides mechanical compliance and flexibility, enabling the sealing ring to be crimped for delivery and then expand to its functional shape upon deployment, improving ease of operation through the delivery system.
Solution Approach 2:
The sealing ring combines the coiled wire tube structure with an outer covering material to create a composite construction. This composite design provides both the collapsibility of the coiled wire framework and the sealing properties of the covering material, while the combination of materials can tolerate manufacturing variations better than a single-material structure, reducing the stringency of precision requirements.
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 design effectively mitigates paravalvular leaks by providing a secure seal between the prosthetic valve and native valve annulus, allowing for a smaller crimp profile and easier delivery, while maintaining effective blood flow and valve function.
Implementation Method 1
the tube is formed from a wire coiled into a repeating shape such that the tube is collapsible
Implementation Method 2
the sealing ring comprising a tube extending circumferentially around the inflow end of the stent, wherein the tube is formed from a wire coiled into a repeating shape such that the tube is collapsible
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
A prosthetic heart valve (300) includes a collapsible and expandable stent (302) extending from an inflow end (330) to an outflow end (332) and a plurality of prosthetic valve leaflets (308) coupled to the stent. The prosthetic heart valve may also include a sealing ring (350) coupled to the inflow end of the stent, the sealing ring comprising a tube (400) extending circumferentially around the inflow end of the stent. The tube may be formed from a wire coiled into a repeating shape, such as a rectangle or a diamond, so that the tube is collapsible. A covering (500) may at least partially surround the tube. The sealing ring may include a first filler (620) positioned within the tube and/or a second filler (610) positioned between the tube and the covering.