Self-Expandable Mitral Stent With Hooked Fixation for PVL Reduction
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Solution Overview
Problem
Existing transcatheter heart valve technologies suffer from paravalvular leakage (PVL) due to malpositioning, calcium interference, incorrect sizing, and implant migration, leading to hemodynamic deterioration and complications such as heart failure, while biological tissues like bovine pericardium degrade and calcify, complicating their use.
Innovation Solution
A self-expandable stent with a stent frame of interconnected endless arms forming a web-like structure and diamond-shaped cells, incorporating a dry bovine pericardium valve and a polyester skirt, designed for minimally invasive implantation, which can be rehydrated and anchored with hooks and struts to secure placement at the mitral annulus, using a specialized treatment to reduce calcification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If transcatheter valves are used to treat mitral valve disease, then valve replacement is achieved, but paravalvular leakage occurs due to malpositioning and implant migration
Solution Approach 1:
The stent is divided into multiple sections (first section and second section) with different expansion characteristics. The first section has a larger maximum outer diameter than the second section, allowing differential expansion to achieve precise fit at the mitral annulus and prevent paravalvular leakage while maintaining valve replacement success
Solution Approach 2:
Different sections of the stent have different mechanical properties and expansion ratios. The first section is designed with larger diameter for anchoring at the annulus, while the second section has smaller diameter to fit the valve structure, creating local quality variations that prevent migration and leakage
2Reliability
If biological tissues like bovine pericardium are used for valve construction, then biocompatibility is improved, but calcification and degradation occur over time
Solution Approach 1:
The bovine pericardium is subjected to specialized treatment that changes its physical and chemical parameters, specifically reducing calcification susceptibility while maintaining biocompatibility. This treatment modifies the tissue properties to resist harmful calcification processes
3Reliability
If existing stent designs are used, then valve replacement is achieved, but trauma during surgery increases and implant accuracy decreases
Solution Approach 1:
The stent employs a self-expanding mechanism with a flexible stent frame made of endless arms forming diamond-shaped cells. This dynamic structure allows the stent to be deployed minimally invasively with reduced surgical trauma while achieving accurate implantation at the mitral annulus through its self-expansion capability
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 stent reduces trauma during surgery, improves implant accuracy, and minimizes PVL by adapting to anatomical needs, ensuring secure fixation and reduced calcification, suitable for elderly patients and reducing the risk of heart failure.
Implementation Method 1
a dry valve made out of bovine pericardium arranged at least at the second section of the stent with the dry bovine pericardium being configured to be rehydrated with a solution
Data Source
AI summary
The invention relates to a self-expendable stent for placement at a mitral annulus that is self-expandable from an undeployed state to a deployed state comprising a stent frame having at least a first section and a second section arranged at a longitudinal axis of the stent, wherein the stent frame is formed by a plurality of endless arms, the arms being connected to one another at connection points forming a web-like structure with diamond-shaped cells; a dry valve made out of bovine pericardium arranged at least at the second section of the stent with the dry bovine pericardium being configured to be rehydrated with a solution, a skirt surrounding the dry valve and comprising at least one of bovine pericardium and polyester, and wherein, in the expanded state, a maximum outer diameter of the first section is larger than a maximum outer diameter of the second section, and wherein at least at a transition between the first section and the second section some of the endless arms extend outwardly beyond the web-like structure to form a hook, which faces the first section.