Inward-Bent Stent Cells for Prosthetic Mitral Valve Recapture
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Solution Overview
Problem
Existing prosthetic heart valve devices face challenges in recapturing and repositioning due to their self-expansion resistance, leading to difficulties in adjusting placement and potential damage to native leaflets, and they often require invasive surgical procedures.
Innovation Solution
A collapsible and expandable prosthetic heart valve device with a stent frame featuring inwardly bent stent cells and a recapture assist mechanism, such as a paddle or slot, allows for efficient recapture and repositioning within a delivery sheath, maintaining native leaflet functionality and minimizing invasive procedures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a self-expanding stent frame is used to provide structural support, then the valve achieves stable positioning and structural integrity, but the device becomes difficult to recapture and reposition due to self-expansion resistance
Solution Approach 1:
The stent frame is divided into multiple modular segments or cells that can independently collapse and expand. This segmentation allows the structure to maintain strength when expanded while enabling controlled collapse for recapture by applying force to specific segments, reducing the overall resistance to recapture.
Solution Approach 2:
The stent frame incorporates dynamic elements such as shape memory alloys or phase-changing materials that allow the structure to transition between expanded and collapsed states on demand. This dynamic property enables the valve to maintain structural integrity during implantation while facilitating easy recapture when needed.
2Stability of the object's composition
If the prosthetic valve is firmly anchored to prevent displacement, then positioning stability is improved, but the ability to adjust placement and reposition is reduced
Solution Approach 1:
The delivery system incorporates preliminary positioning mechanisms such as expandable balloons or anchoring elements that can be deployed before final valve implantation. These preliminary actions allow the operator to adjust the valve position while minimizing displacement of native structures, and enable recapture if further adjustment is needed.
Solution Approach 2:
The valve design incorporates adjustable parameters such as expandable anchoring elements or repositionable mounting mechanisms that allow the operator to modify the degree of anchoring. This enables the valve to be firmly secured when properly positioned while allowing for adjustment or recapture if positioning needs to be changed.
3Ease of operation
If the stent frame is designed for easy recapture, then repositioning capability is improved, but the structural support and stability during implantation may be compromised
Solution Approach 1:
The stent frame incorporates nested or telescoping structures where inner components can collapse within outer components during recapture. This nesting mechanism allows the valve to maintain full structural support when expanded for implantation while enabling compact collapse for easy recapture and repositioning.
Solution Approach 2:
The delivery system incorporates intermediary structures such as expandable balloons or temporary anchoring elements that provide structural support during implantation. These intermediaries can be deployed to stabilize the valve frame while it is being positioned, then removed or collapsed to facilitate easy recapture if repositioning is needed.
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
Enables precise positioning and recapturing of the prosthetic heart valve without damaging native leaflets, facilitating less invasive procedures and improved coaptation of prosthetic leaflets, thus enhancing treatment efficacy.
Implementation Method 1
stent cells that are bent radially inward at least partially over the flow channel
Data Source
AI summary
A collapsible and expandable prosthetic mitral valve stent is provided with improved recapture into a distal lumen of a delivery sheath. Various embodiments comprise a valve support within the interior of a stent frame and defining a flow channel therethrough, wherein the top or upstream of the valve support comprises a row, or a plurality, of stent cells that are bent radially inward at least partially over the flow channel. Some embodiments may comprise a recapture assist mechanism, such as an open paddle, attached to one or more of the inwardly bent stent cells and adapted to receive and/or engage a wire to aid in positioning, expansion, recapture and/or implanting the device in a patient's heart chamber.