Stent retrievers for acute ischemic stroke: technological advances, clinical applications, and future perspectives

Acute ischemic stroke caused by large vessel occlusion remains a leading cause of death and disability despite established reperfusion therapies. Although stent retriever-based thrombectomy has become the standard of care, outcomes are still constrained in complex occlusions and anatomically challenging cases. This review summarizes and critically appraises recent advances in stent retriever technology, thrombectomy techniques, and evidence expansion in acute ischemic stroke. Device development has progressed from first-generation retrieval systems to self-expanding stent retrievers and recent integrated retrieval-protection platforms, leading to improved clot engagement, higher first-pass reperfusion, and reduced distal embolization. Parallel refinements in procedural strategies including combined aspiration catheters, balloon guide catheters, and dual-stent techniques have enhanced recanalization efficiency and procedural control. Clinical evidence has extended thrombectomy indications beyond conventional time windows to include posterior circulation occlusion, large infarct cores, and selected medium/distal vessel occlusions under imaging-guided selection. Advances in thrombus characterization, biomaterials, surface engineering, and territory-specific devices are further enabling more tailored mechanical approaches. Nevertheless, fibrin-rich resistant thrombi, embolic complications, vascular injury, and limited high-level evidence for emerging devices remain unresolved challenges. Ongoing integration of engineering innovation and clinical data is expected to support more individualized and safer thrombectomy strategies with improved functional outcomes.