Microstructured Thin Film Nitinol for a Neurovascular Flow-Diverter

Area of Science:

• Biomedical Engineering
• Materials Science
• Medical Devices

Background:

• Cerebral aneurysms are life-threatening due to weakened blood vessels.
• Flow-diverters offer a promising treatment by redirecting blood flow away from aneurysm sacs.
• Existing flow-diverters lack mechanical safety data for complex, curved neurovascular anatomy.

Purpose of the Study:

• To investigate the mechanical behavior and structural safety of a novel microstructured thin film nitinol (TFN) membrane for flow-diverters.
• To establish fundamental aspects of TFN membrane mechanics, including stretching and bending.
• To determine optimal design parameters for TFN flow-diverters in curved arteries.

Main Methods:

• Computational modeling to simulate mechanical behaviors.
• In vitro experimental testing to assess flexibility.
• In vivo studies using swine models for deployment and safety evaluation.

Main Results:

• The TFN membrane exhibits hyper-elastic behavior with negligible strain change during 180° bending and over 500% radial stretching.
• Simulations identified optimal joint locations for TFN integration with stent frames.
• In vitro tests confirmed multi-modal bending flexibility.
• In vivo studies demonstrated conformal deployment in curved swine arteries without significant complications.

Conclusions:

• The microstructured TFN membrane possesses ideal mechanical properties for neurovascular applications.
• This novel flow-diverter shows promising mechanical safety and deployability in curved blood vessels.
• Further validation supports its potential as an effective treatment for cerebral aneurysms.