Merci retrievers as access adjuncts for reperfusion catheters: the grappling hook technique

Expeditious, stable access in acute ischemic stroke is foundational for mechanical revascularization. Proximal vascular tortuosity and unfavorable anatomy may impede the access necessary for revascularization, particularly when large-caliber catheters are used. We describe an approach using the Merci retriever to gain stable catheter access for aspiration.

To assess the technical feasibility of using the Merci retriever system as an access adjunct in acute ischemic stroke and tortuous ophthalmic segment anatomy.

The acute ischemic stroke database was queried, and 3 patients presenting with acute ischemic stroke and tortuous proximal anatomy who were treated with mechanical thrombectomy and the Merci retriever as an access adjunct were identified. Patient charts and procedure reports were reviewed.

In each of the patients, the ophthalmic segment of the internal carotid artery proved difficult to navigate. An appropriately sized Merci retriever was deployed in the M1 segment. Gentle tension on the retriever was applied, altering the angle at which the aspiration catheter navigated the ophthalmic segment, affording rapid access past the ophthalmic artery origin and into the target vessel. The 18 L microcatheter and retriever were withdrawn, followed by aspiration and clot maceration with the Penumbra aspiration system.

Tortuous proximal anatomy may impede access to an occluded vessel. Use of tension on a deployed Merci retriever straightens the course of the wire, changing the angle that the aspiration catheter makes with the vessel. In the setting of unfavorable anatomy, this technique may be used to advance an aspiration catheter to the target lesion.