Stent Retriever Types

Stent retrievers are classified based on design, mechanism of action, size, material, clinical application, and deployment technique.

• Single-Stent Retriever: Single stent deployed inside the clot to capture it during retrieval.
• Double-Stent Retriever: Dual stent-like structures designed for better clot entrapment in large occlusions.
• Self-Expanding Stents: Automatically expand upon deployment to increase clot contact surface.

• Small: For delicate procedures and small-caliber vessels.
• Medium: Standard size for middle cerebral arteries.
• Large: For large vessels (e.g., internal carotid, basilar).

• Nitinol (Nickel-Titanium alloy): Offers flexibility, durability, and shape-memory.
• Polymers: Occasionally combined for additional flexibility or support.

• Acute Ischemic Stroke: Primary use in neurointervention.
• Other Vascular Territories: Explored use in coronary or peripheral procedures.

• Manual Deployment: Controlled by the physician.
• Catheter-Driven/Automated: Enhanced control with system-guided expansion.

• Proximal Retrieval: Engages clot closest to the heart.
• Distal Retrieval: For selective or distal occlusion removal.

• Design: Self-expanding, closed-cell nitinol.
• Data: SWIFT, SWIFT PRIME (~85–90% success).
• Pros: High first-pass efficacy, well-studied.
• Use: Versatile across anatomies.

• Design: Open-cell nitinol with radial force gradient.
• Data: TREVO 2, DAWN.
• Pros: Radiopaque, effective for firm clots.
• Use: Both anterior and posterior circulation.

• Design: Dual-layer nitinol for thrombus trapping.
• Data: High reperfusion, low hemorrhage.
• Pros: Gentle on vessels, effective for fibrin-rich clots.

• Design: Braided nitinol optimized for large vessels.
• Use: Anterior circulation LVOs.
• Pros: Effective for large clot burden.

• Design: Hybrid laser-cut nitinol (open/closed cells).
• Pros: Reliable deployment, medium-large occlusions.

• Design: Self-expanding nitinol with unique struts.
• Data: European use; early data promising.
• Pros: Low vessel trauma, comparable efficacy.

• Design: Adjustable diameter during deployment.
• Pros: Real-time control, high adaptability.
• Use: Tailored engagement of various clot types.

• Design: Mini nitinol stent for distal/small vessels.
• Pros: Excellent in complex anatomies.

Stent retrievers play a central role in mechanical thrombectomy for AIS. While Solitaire™ and Trevo remain benchmarks due to robust clinical validation, newer devices such as Tigertriever and EmboTrap II offer innovative features tailored to clot morphology and vessel anatomy. The optimal choice hinges on patient-specific factors, clot characteristics, and operator preference.

In a scoping review Song et al.from: - Austin Health, Melbourne (Radiology) - St Vincent’s Health, Melbourne (Interventional Neuroradiology) - Monash Health, Melbourne (Neurosurgery & Imaging) - Eastern Health/MU, Melbourne - Northern Health/Univ. of Melbourne, Melbourne - SAHMRI, Adelaide - Deakin Univ., Geelong published in the Journal of Clinical Neuroscience with the purpose to map the landscape of stent retriever devices used in mechanical thrombectomy for acute ischemic stroke, stratified by device type and occlusion location. They concluded that Solitaire and Trevo dominate clinical use (~57 % of cases), primarily in M1 and ICA occlusions. Many devices remain under‑studied, especially in distal (ACA, M3+) occlusions. There is a notable evidence gap for newer stent retrievers in medium/distal vessel territory ¹⁾.

This review, while comprehensive in device enumeration, falls short in critical appraisal. By pooling data from 133 heterogeneous studies without quality stratification or bias assessment, it gives an inflated sense of evidence. The emphasis on device frequency—rather than outcomes or head‑to‑head efficacy—renders the conclusions superficial. The assertion of a “strong evidence base” for conventional devices is misleading; no meta‑analysis or performance metrics are provided. The claim that distal occlusions are understudied is unsurprising, but the authors offer no actionable framework or proposals for future targeted trials. The review reads more like a registry report than a scoping synthesis intended to inform practice. Novelty is minimal, relevance limited.

Fail. A descriptive registry devoid of depth, critique, or synthesis.

This scoping review inventories devices and locations but provides zero guidance on device choice or procedural strategy. Relying on mere frequency does not equate to best practice.

Inventory, not insight.

2/10

Corresponding author: janesong1029@gmail.com. The article was published online ahead of print on June 23, 2025.