When an interventional neuroradiologist prepares to perform a mechanical thrombectomy, one of the technical decisions involves choosing between aspiration and stent retriever methods, or combining the two. The aspiration vs stent retriever question comes up often among patients researching stroke treatment, but the honest answer is that neither technique is universally superior — the choice depends on the specific clot, vessel anatomy, and the clinical judgment of the treating physician. This article outlines how each technique generally works and the considerations that typically guide the decision.
How Does the Stent Retriever Technique Work?
A stent retriever is a self-expanding mesh device that is delivered through a microcatheter to the site of the clot within a brain artery. Once positioned, it expands and integrates with the clot, and the device is then withdrawn along with the trapped material to remove the obstruction, typically while suction is applied to help prevent fragments from breaking loose. This approach has a long track record in acute ischemic stroke treatment and is often paired with a temporary balloon to reduce forward blood flow during clot removal. Vessel tortuosity and clot consistency can both influence how well a stent retriever performs in a given case.
How Does the Aspiration Technique Work?
Aspiration, sometimes referred to using the acronym ADAPT (a direct aspiration first-pass technique), involves advancing a large-bore catheter directly to the clot and applying continuous suction to draw it out, without necessarily deploying a separate mesh device. Proponents of this approach point to its relative simplicity and the ability to remove a clot in a single pass in some cases. As with stent retrievers, the effectiveness of aspiration can depend on clot composition, the diameter of the vessel, and how accessible the occlusion is to the catheter.
What Does "First-Pass Success" Mean in This Context?
First-pass success, or the first-pass effect, is a well-established concept in thrombectomy literature referring to achieving complete or near-complete removal of a clot on the very first attempt, without needing additional passes. This concept matters because studies discussed in the field have associated fewer passes with generally more favorable outcomes, though results vary by patient. Both aspiration and stent retriever techniques aim for a high first-pass success, and neither approach guarantees it in every case — clot characteristics and vessel anatomy remain significant variables regardless of which technique is chosen.
Why Are Aspiration and Stent Retrievers Often Combined?
Rather than treating aspiration and stent retrievers as strictly competing methods, many interventional teams use a combined approach, deploying a stent retriever while simultaneously applying aspiration through a coaxial catheter system. This combined technique is intended to capture clot fragments that might otherwise break free during retrieval, potentially reducing the risk of distal embolization. Whether a physician begins with aspiration alone, a stent retriever alone, or a combined approach from the outset often reflects operator preference, clot location, and real-time findings during the procedure rather than a fixed rule.
A Note on the KinG Intracranial Revascularization Device
Among the devices used in stent retriever-based thrombectomy is the KinG Intracranial Revascularization Device from INVAMED. As stated by the manufacturer, KinG is described as "a stent retriever or flow restoration device for acute ischemic stroke, capturing and removing large clots from the intracranial arteries, swiftly restoring perfusion." It is positioned within the broader category of devices used for acute stroke therapy and large vessel occlusion. As with any thrombectomy device, suitability for a given patient and procedure is determined by the treating physician, and availability varies by country in accordance with the Instructions for Use (IFU).
Does a higher first-pass success rate mean a technique is better overall?
First-pass success is one factor associated with favorable outcomes in thrombectomy literature, but it is not the only consideration, and it can be influenced by clot composition and vessel anatomy regardless of technique. No single technique guarantees first-pass success in every case. A qualified physician weighs multiple factors when selecting an approach.
Device availability and regulatory status vary by country. Please contact INVAMED or your authorized local distributor for current regulatory information applicable to your region.