Vaso-Occlusive Braid-Coil Structure to Reduce Interlocking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional vaso-occlusive devices face issues such as interlocking between coil and braid portions, difficulty in delivering longer devices through small catheters, and inadequate retention in wide neck aneurysms, which complicates procedures and requires additional stents or balloons.
Innovation Solution
A vaso-occlusive device with a braided portion and a distal coil segment having a specific bending stiffness ratio within the range of 0.5 to 1.0, allowing for reduced engagement and improved maneuverability, while maintaining atraumatic properties and expandability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a vaso-occlusive device with both coil and braid portions is used, then neck coverage and retention in wide neck aneurysms are improved, but interlocking engagement between coil and braid occurs preventing proper deployment
Solution Approach 1:
The patent applies different bending stiffness characteristics to different portions of the device. The coil portion has a first bending stiffness while the braid portion has a second bending stiffness, where the ratio between them is controlled to be between 0.5-2.0. This local differentiation allows the coil to be sufficiently flexible to pass through delivery catheters without excessive engagement, while the braid provides adequate stiffness for neck coverage and retention in wide neck aneurysms.
2Object-affected harmful factors
If the coil portion is made softer to be atraumatic, then tissue damage is prevented, but engagement with the braid increases making deployment difficult
Solution Approach 1:
The patent controls the engagement between coil and braid by adjusting physical parameters, specifically the bending stiffness ratio. By maintaining the ratio between the coil's bending stiffness and braid's bending stiffness within 0.5-2.0, the device achieves optimal balance: the coil remains soft enough to be atraumatic to aneurysm tissue while having sufficient stiffness relative to the braid to prevent excessive interlocking and engagement during deployment.
3Length of moving object
If longer vaso-occlusive devices are used to fill large aneurysms, then occlusion effectiveness is improved, but delivery through small profile catheters becomes difficult
Solution Approach 1:
The patent creates a dynamically adaptable structure where the coil portion can flex and compress during delivery, then expand to its full length and configuration after deployment. The controlled bending stiffness ratio enables the device to transition from a compressed delivery state through small profile catheters to an expanded functional state in the aneurysm, achieving both long device length for large aneurysm filling and easy deliverability through small catheters.
Data Source
Figure 1
Figure 2A~2B
Figure 3~4
AI summary
A vaso-occlusive device comprising an elongate main portion (such as a braided portion) having a plurality of openings along a length of the main portion (such as the openings between the strands of a braid). The main portion has a first bending stiffness. An atraumatic distal segment coupled to, and extending distally from, the distal end of the braided portion. The distal segment has a second bending stiffness. The ratio of the second bending stiffness to the first bending stiffness is within a specified range, which alleviates the problem of the distal segment entering and engaging the openings of the main portion while maintaining deployment performance of the device.