Guide-Extension Catheter-Assisted Bail-Out Thrombus Aspiration During PCI for Thrombus-Rich Acute Coronary Syndromes: Contemporary Review and Clinical Case Examples

Large intracoronary thrombus burden during percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS) remains technically challenging when conventional manual aspiration is ineffective or dedicated thrombectomy systems are unavailable, unsuitable, or undeliverable. Routine aspiration thrombectomy is not guideline-supported, but selective bail-out thrombus-removal strategies remain relevant in refractory thrombus-rich PCI. This contemporary narrative review, supplemented by six retrospective single-center clinical examples, describes off-label guide-extension catheter (GEC)-assisted thrombus aspiration and places it within the current thrombectomy landscape, including manual aspiration catheters, sustained mechanical aspiration platforms, and stent-retriever-based systems. The heterogeneous examples, predominantly involving the right coronary artery, are educational and hypothesis-generating only: they illustrate procedural mechanics, patient selection, technical pitfalls, and risk mitigation, but do not provide efficacy or safety evidence. GEC-assisted aspiration may be considered when bulky proximal thrombus cannot be captured by smaller catheters or when a GEC can be positioned coaxially near the thrombus face under uninterrupted negative pressure. The technique remains operator-dependent, off-label, and anatomically constrained and should be regarded as a contingency maneuver rather than an alternative to purpose-built systems with more formal device-specific evaluation. Prospective registries and comparative studies are required before efficacy, safety, or relative value can be established.