Variable Stiffness Heart Valve Stent for Conductive Pathway Protection
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Solution Overview
Problem
Transcatheter prosthetic heart valves can contribute to cardiac pacing issues post-implantation, with approximately 10-30% of self-expanding transcatheter aortic valve procedures requiring pacemaker implantation due to the impact on the heart's conductive pathways.
Innovation Solution
A stented transcatheter prosthetic heart valve with a lattice structure stent frame that self-expands from a compressed condition to a natural, expanded condition, featuring a varying radial stiffness along the circumference. The stent frame includes regions of reduced radial stiffness aligned with conductive pathways, minimizing the force exerted on these areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a self-expanding stent frame with uniform radial stiffness is used to ensure adequate anchoring and resistance to compressive forces, then the prosthetic valve achieves stable fixation at the native valve site, but the conductive pathways of the heart are impacted, leading to cardiac pacing issues
Solution Approach 1:
The stent frame incorporates regions of varying radial stiffness along its circumference, with reduced stiffness specifically at locations corresponding to cardiac conductive pathways. This local differentiation allows the stent to maintain overall structural integrity and anchoring stability while minimizing harmful impacts on sensitive conductive tissues in specific regions.
2Strength
If the stent frame is designed with high radial hoop strength to resist turbulent blood flow and vessel wall diameter changes, then long-term anchoring is achieved, but the force exerted on conductive pathways increases, contributing to pacemaker requirements
Solution Approach 1:
The stent frame is engineered with non-uniform radial stiffness distribution, featuring high-strength regions for overall structural support and anchoring, and localized reduced-stiffness regions where conductive pathways are present. This spatial variation in mechanical properties allows the stent to exert necessary anchoring force while minimizing stress on sensitive conductive tissues.
Solution Approach 2:
The stent frame is divided into multiple circumferential segments with different stiffness characteristics. High-stiffness segments provide structural integrity and resistance to compressive forces, while low-stiffness segments are positioned to accommodate conductive pathways, reducing the force transmitted to these sensitive structures.
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 reduces the impact on the heart's conductive pathways, potentially lowering the need for pacemaker implantation after valve placement, while maintaining adequate anchoring and fatigue strength for long-term fixation.
Implementation Method 1
The stent frame is configured to self-expand from a compressed condition for transluminal delivery to a natural, expanded condition
Data Source
AI summary
A prosthetic heart valve including a stent frame and a valve structure. The valve structure is disposed within a lumen of the stent frame. The stent frame is configured to self-expand from a compressed condition for transluminal delivery. The stent frame has a lattice structure forming a tubular shape defining a circumference and a plurality of closed cells arranged to define a band exhibiting a variable radial stiffness. The prosthesis can be deployed such that the band applies a minimal force on to anatomical locations relating to the heart's conductive pathways. A region of the band otherwise having low radial stiffness is located at or over a conductive pathway upon final implant.