Braided Occluder Frame With Access Passage for Left Atrial Access
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Solution Overview
Problem
Conventional occluders for atrial septal defects pose challenges in accessing the left atrium due to their impenetrable metal fabric or wire structure, leading to tissue erosion and bulging, which complicates subsequent medical procedures and increases thrombus formation risk.
Innovation Solution
A braided frame design with an access passage, featuring a closed-end braid, wire loops, polymer coating, and rolled-over braid configuration, along with a penetrable patch closure, to facilitate uniform loading, reduce bulging, and minimize tissue erosion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional occluder with continuous metal fabric or wire disc is used, then effective occlusion is achieved, but access to the left atrium is blocked and tissue erosion occurs
Solution Approach 1:
The continuous metal fabric or wire disc is segmented by creating an access passage through it. This segmentation allows the disc to maintain its occlusive function while providing a pathway for medical devices to access the left atrium, resolving the contradiction between effective occlusion and ease of access.
Solution Approach 2:
The disc structure is modified locally by creating an access passage at a specific location. This local modification allows penetration for left atrium access while the rest of the disc maintains its continuous structure for effective occlusion, addressing both requirements simultaneously.
2Object-affected harmful factors
If the occluder is made softer to reduce tissue erosion, then tissue compliance improves, but bulging into the atrium increases
Solution Approach 1:
The braid density is varied locally across different regions of the occluder. The discs have higher braid density (e.g., 8-12 wires per inch) to prevent bulging, while the waist has lower braid density (e.g., 4-6 wires per inch) to reduce tissue erosion. This local quality variation resolves the contradiction between preventing bulging and reducing tissue erosion.
Solution Approach 2:
The occluder employs asymmetric braid density distribution, with denser braiding in the disc regions and sparser braiding in the waist region. This asymmetric design allows each region to have optimized properties: discs resist bulging while the waist minimizes tissue erosion.
3Reliability
If patch closure is used to provide occlusive effect, then occlusion is achieved, but patch bulging occurs in the center of the device
Solution Approach 1:
The braid density is increased locally in the disc regions where patch closures are applied. This higher local density provides structural support to prevent patch bulging in the center of the device while maintaining the occlusive effect of the patch closures.
Solution Approach 2:
The occluder combines patch closure material with braided metal fabric or wire. The composite structure integrates the occlusive properties of the patch with the structural support of the denser braid in the disc regions, preventing patch bulging while maintaining effective occlusion.
Data Source
AI summary
Braided occluding devices having an access passage and methods including the same are described herein. The occluding device includes a braided frame which includes. The braided frame includes an annular distal disc portion, a waist member, and an annular proximal disc portion defining a passageway through the braided frame. The braided frame is formed with a closed end braid.