Transcatheter Valve Prosthesis with Flared Inflow End
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Solution Overview
Problem
Heart valve diseases, such as abnormal leaflet tissue and tissue position, lead to valve dysfunction, necessitating a minimally invasive surgical procedure for valve replacement without removing the native heart valve, where existing prostheses face challenges like paravalvular leakage and in-folding due to mismatched anatomy.
Innovation Solution
A transcatheter valve prosthesis with a radially self-expandable tubular body featuring a non-uniform stent stiffness design, including a mesh-like structure with selectively disconnected struts and a flared inflow end, allowing for better anatomical conformity and reduced in-folding, and a fabric covering for sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional valve prosthesis with uniform stent structure is used, then the device is simpler to manufacture, but it causes paravalvular leakage and in-folding due to mismatched anatomy
Solution Approach 1:
The stent structure employs non-uniform cell configurations where different axial and circumferential regions have different cell sizes, shapes, and connectivity patterns. The inflow end features a flared geometry with larger cell openings, while the outflow end has a more compact structure. This local variation in stent architecture allows different portions to adapt to varying anatomical conditions, improving sealing performance without requiring a completely complex custom design for each patient
Solution Approach 2:
The stent is divided into multiple circumferential rows of cells with different characteristics. Each row can be independently optimized for its specific location, with some rows having larger cells for compliance and others having smaller cells for structural support. This segmentation allows the stent to function as a unified structure while incorporating local variations that address anatomical mismatches and prevent paravalvular leakage
2Adaptability or versatility
If a rigid stent structure is used, then structural integrity is maintained, but adaptability to patient anatomy is reduced
Solution Approach 1:
The stent structure incorporates dynamic characteristics through its mesh-like cellular configuration that can deform and adapt during deployment and in response to physiological movements. The interconnected struts and cells allow controlled flexibility while maintaining overall structural integrity, enabling the stent to conform to patient anatomy without compromising strength
Solution Approach 2:
The stent combines materials with different mechanical properties to achieve both adaptability and structural integrity. The use of shape memory alloys or elastomeric materials provides a composite structure that can be rigid when needed for structural support and flexible when needed for anatomical conformity, resolving the contradiction between strength and adaptability
3Ease of operation
If a minimally invasive transcatheter procedure is used, then patient trauma is reduced, but delivery and deployment complexity increases
Solution Approach 1:
The valve prosthesis is designed to be nested within a delivery catheter in a compressed state, allowing it to be delivered through minimally invasive access routes. The self-expandable structure is contained within the delivery system until deployment, whereupon it expands to its functional configuration. This nesting approach enables minimally invasive delivery while managing the complexity of the delivery system through standardized catheter designs
4Object-affected harmful factors
If the native heart valve is not removed and a prosthesis is implanted instead, then surgical invasiveness is reduced, but paravalvular leakage occurs due to anatomical mismatch
Solution Approach 1:
The prosthesis incorporates localized sealing structures and non-uniform stent configurations that specifically address the interface between the prosthesis and native valve annulus. Different regions of the stent have different cell sizes and connectivity to optimize sealing at the paravalvular region while maintaining overall structural function, thereby reducing leakage without requiring complete anatomical matching
Solution Approach 2:
The stent structure acts as an intermediary element between the prosthesis and the native heart valve anatomy. Its mesh-like cellular configuration provides a transition zone that accommodates anatomical variations and mismatches, allowing the prosthesis to function effectively without requiring precise anatomical matching or removal of the native valve
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 enhances adaptability to patient anatomy, reduces paravalvular leakage, and maintains structural integrity, facilitating easier delivery and deployment while preventing in-folding and ensuring a secure seal.
Implementation Method 1
a radially, self-expandable tubular body (5) having a proximal, inflow end (10) and a distal, outflow end (15)
Data Source
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AI summary
A replacement heart valve system and a method of implanting a replacement heart valve in a patient. The replacement heart valve system includes a radially self-expandable tubular body and a valve including a plurality of leaflets coupled to the tubular body. The tubular body includes interconnected struts defining circumferential rows of cells, and has an outflow end and an inflow end that flares radially outward so as to have a larger outer diameter than that of the outflow end. A first row of proximal-most cells formed at the inflow end includes circumferentially adjacent cells that are disconnected from each other so as to be spaced from each other in the circumferential direction. A method of implanting the replacement heart valve includes delivering from a delivery catheter the tubular body, and expanding the tubular body such that the proximal-most cells are disposed against the native heart valve annulus.