Expandable Cardiac Valve Stent With Positioning and Retaining Arches
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Solution Overview
Problem
Existing minimally-invasive cardiac valve treatments face challenges with precise positioning and anchoring of endoprostheses, leading to potential leakage, displacement, and detachment due to peristaltic heart motion, posing risks such as coronary ischemia and myocardial infarction.
Innovation Solution
An expandable stent with positioning and retaining arches, auxiliary arches, and fastening portions, designed for precise engagement with native heart valve pockets, minimizes longitudinal displacement and ensures secure anchoring through radial forces and multiple fastening mechanisms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a self-expandable stent with positioning arches is used to anchor the endoprosthesis, then the anchoring capability is improved, but the positioning precision deteriorates due to difficulty in exact longitudinal alignment
Solution Approach 1:
The stent is divided into functionally distinct segments: positioning arches (for anchoring in valve pockets), retaining arches (for longitudinal positioning), and auxiliary arches (for additional support). This segmentation allows each component to be optimized for its specific function, resolving the contradiction between anchoring capability and positioning precision.
Solution Approach 2:
The positioning arches are pre-configured with specific geometries and articulation points that guide them into the native valve pockets during deployment. This preliminary configuration ensures that the stent automatically achieves correct longitudinal alignment and angular orientation once deployed, eliminating the need for complex manual positioning while maintaining secure anchoring.
2Strength
If anchoring barbs are used to engage with the vascular wall, then the anchoring strength is improved, but the risk of displacement due to peristaltic motion increases
Solution Approach 1:
The stent employs articulated segments that can dynamically adjust to peristaltic motion of the heart and blood vessels. The joints between stent segments allow controlled movement while maintaining overall anchoring position, preventing displacement during cardiac cycles while retaining strong anchoring capability.
Solution Approach 2:
Different portions of the stent have different mechanical properties: the positioning arches have high rigidity for strong anchoring in valve pockets, while the connecting segments have controlled flexibility to accommodate peristaltic motion. This local differentiation of mechanical properties resolves the contradiction between anchoring strength and stability against displacement.
3Measurement precision
If multiple positioning arches are used to improve positioning accuracy, then the positioning precision is improved, but the device complexity increases
Solution Approach 1:
Each positioning arch serves multiple functions: anchoring the stent in native valve pockets, providing longitudinal positioning reference, and contributing to radial expansion force. This multi-functionality reduces the need for separate components, maintaining positioning precision while limiting complexity increase.
Solution Approach 2:
The positioning arches are integrated with the main stent body through articulated connections, forming a unified structure that deploys as a single unit. This merging of components simplifies the delivery system and deployment procedure while maintaining the positioning precision benefits of multiple arches.
4Ease of operation
If the stent is designed for transluminal implantation, then the ease of operation is improved, but the anchoring reliability deteriorates due to potential inexact implantation
Solution Approach 1:
The stent employs self-expanding positioning arches that automatically engage with native valve pockets upon deployment. This self-positioning mechanism eliminates the need for complex manual alignment procedures, maintaining ease of transluminal implantation while ensuring reliable and exact positioning through the inherent mechanical guidance of the arches.
Data Source
Figure 1a
Figure 1b
Figure 1c
AI summary
The present invention relates to a stent (10) for the positioning and anchoring of a valvular prosthesis (100) in an implantation site in the heart of a patient. Specifically, the present invention relates to an expandable stent for an endoprosthesis used in the treatment of a narrowing of a cardiac valve and/or a cardiac valve insufficiency. So as to ensure that no longitudinal displacement of a valvular prosthesis (100) fastened to a stent (10) will occur relative the stent (10) in the implanted state of the stent (10), even given the peristaltic motion of the heart, the stent (10) according to the invention comprises at least one fastening portion (11 11a) via which the valvular prosthesis (100) is connectable to the stent (10). The stent (10) further comprises positioning arches (15a, 15b, 15c) and retaining arches (16a, 16b, 16c), whereby at least one positioning arch (15a, 15b, 15c) is connected to at least one retaining arch (16a, 16b, 16c).