Hemodynamics of Flow Diverters.

Area of Science:

• Biomedical Engineering
• Neurosurgery
• Medical Devices

Background:

• Cerebral aneurysms are arterial wall bulges that can rupture, causing strokes.
• Endovascular treatment involves implanting flow diverters or stents to promote aneurysm thrombosis and healing.
• Device mesh structure, characterized by porosity and pore density, is crucial for efficacy.

Purpose of the Study:

• To evaluate the flow alteration induced by five commercial neurovascular devices in an idealized aneurysm model.
• To correlate device mesh characteristics (porosity, pore density) with their flow-mitigating efficacy.
• To inform future device design, treatment planning, and outcome prediction for cerebral aneurysms.

Main Methods:

• Comparison of flow alteration in an idealized sidewall aneurysm model with five commercial devices (Neuroform, Enterprise, LVIS, Pipeline, FRED).
• Quantification of intraneurysmal kinetic energy reduction.
• Analysis of device mesh porosity and pore density.

Main Results:

• All tested devices substantially reduced intraneurysmal kinetic energy compared to the non-stented case.
• Coarse-mesh stents reduced flow by 65-80%; fine-mesh flow diverters achieved near-complete stagnation (∼98%).
• A trend indicated greater efficacy with decreasing porosity and increasing pore density.

Conclusions:

• Device porosity and pore density are key factors influencing the hemodynamic effects of neurovascular devices on cerebral aneurysms.
• Standardized studies with large datasets are needed to reach consensus on optimal device selection and predict treatment outcomes.
• Incorporating biochemical variables may enhance the predictive value of future studies.