Variable Porosity Intravascular Implant for Selective Aneurysm Occlusion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current vascular occlusion devices, such as stents, uniformly block blood flow and pressure, inadvertently impeding flow to adjacent vessels like perforator vessels, which can cause unintended harm during treatment of aneurysms and arteriovenous malformations, especially near critical brain tissue.
Innovation Solution
A tubular vascular occlusion device with variable porosity regions along its length, formed from braided filaments of different cross-sectional shapes, allowing for selective occlusion of aneurysms while maintaining blood flow to adjacent vessels, achieved by altering the shape of filaments in specific regions while maintaining a constant pick count and braid angle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a uniform porosity stent is used to occlude blood flow to an aneurysm, then the aneurysm is effectively blocked, but blood flow to adjacent perforator vessels is also blocked causing unintended harm
Solution Approach 1:
The stent is designed with variable porosity along its length, featuring a first porosity region with lower porosity for effective aneurysm occlusion and a second porosity region with higher porosity to preserve blood flow to adjacent perforator vessels. This local differentiation of porosity allows the same device to simultaneously protect the aneurysm while maintaining flow to surrounding healthy tissue.
2Object-affected harmful factors
If the porosity of the stent is increased to allow blood flow to adjacent vessels, then flow to perforator vessels is preserved, but the occlusion effectiveness for the aneurysm is reduced
Solution Approach 1:
The stent is divided into distinct porosity regions along its longitudinal axis. The first porosity region (with lower porosity) is positioned to occlude the aneurysm, while the second porosity region (with higher porosity) is positioned to allow flow to adjacent vessels. This spatial segmentation of functional properties resolves the contradiction by assigning different porosity characteristics to different segments of the same device.
3Reliability
If variable porosity regions are created by changing filament cross-sectional shapes, then selective occlusion is achieved, but manufacturing complexity increases
Solution Approach 1:
The variable porosity is achieved by changing the cross-sectional shape parameter of the filaments (from circular to non-circular shapes such as flattened, triangular, or rectangular) rather than changing the number of filaments or braiding pattern. This parameter-based approach maintains a constant pick count and braid angle, simplifying the manufacturing process while still achieving the desired variable porosity effect.
Data Source
AI summary
A vascular occlusion device for effectively occluding blood flow and pressure to a vascular defect while simultaneously not occluding blood flow and pressure to adjacent vasculature is provided. The vascular occlusion device can include a tubular member that has variable porosity regions along its length. The tubular member can be formed of a plurality of filaments that have different cross-sectional shapes along their length that are indexed to the variable porosity regions along the length of the tubular member.