Toward a novel stent retriever: design, optimization and experimental validation.

Area of Science:

• Biomedical Engineering
• Neurosurgery
• Medical Devices

Background:

• Acute ischemic stroke is a major cause of death and disability worldwide.
• Mechanical thrombectomy with stent retrievers improves outcomes but struggles in complex vasculature.
• Current devices lack conformability, reducing clot retention efficacy in tortuous and bifurcated arteries.

Purpose of the Study:

• To introduce and evaluate a novel self-expandable stent retriever design.
• To enhance conformability and thrombus retention in complex vascular anatomies.
• To optimize the stent retriever for improved radial force and flexibility.

Main Methods:

• Finite element analysis to assess biomechanical parameters (strain, radial force).
• Multi-objective optimization to balance radial force and minimize strain.
• In vitro thrombectomy experiments in realistic stenotic and curved vessel models.

Main Results:

• The optimized stent showed 18.2% lower bending moment compared to commercial devices.
• Improved cross-sectional geometry maintenance under deformation indicates enhanced flexibility.
• Effective thrombus engagement demonstrated in vitro, though bifurcated models presented challenges.

Conclusions:

• The novel stent retriever design offers a promising balance of flexibility and radial strength.
• This design has the potential to improve mechanical thrombectomy outcomes in complex vascular environments.
• Further development is needed to address challenges in bifurcated anatomies.