Hemodynamic differences between Pipeline and coil-adjunctive intracranial stents

Area of Science:

• Biomedical Engineering
• Medical Devices
• Computational Fluid Dynamics

Background:

• Modern intracranial stents aim to create 'flow diverter lights' by increasing metal surface coverage.
• This approach assumes flow diversion is directly proportional to metal surface coverage.

Purpose of the Study:

• To evaluate the assumption that flow diversion correlates linearly with metal surface coverage.
• To compare hemodynamic effects of low metal coverage stents (ATLAS, Enterprise), LVIS Blue, and Pipeline flow diverter.

Main Methods:

• Computational fluid dynamics (CFD) analysis on virtual stent deployments.
• Evaluation of velocity vectors, wall shear stress, aneurysm inflow rate, and turnover time.

Main Results:

• Pipeline showed localized inflow jets; LVIS Blue had asymmetric jets; ATLAS and Enterprise had broader clusters.
• All devices reduced wall shear stress, with Pipeline showing the greatest reduction.
• Pipeline significantly increased turnover time, unlike ATLAS, Enterprise, and LVIS Blue.

Conclusions:

• Effective flow diversion is a design threshold, not solely dependent on metal surface coverage.
• Significant hemodynamic differences exist between flow diverters and moderate/low-porosity stents.
• Device porosity and design play crucial roles in achieving effective flow diversion.