Rapid intracranial clot removal with a new device: the alligator retriever

Abstract

Background and purpose: Despite availability of an approved drug to treat acute cerebral ischemia, most patients with stroke do not realize a good outcome. A method that would rapidly increase or restore cerebral perfusion before irreversible cell death should improve patient outcomes.

Materials and methods: We recently had the opportunity to treat 6 middle-aged-to-elderly patients who presented with signs and symptoms of acute cerebral ischemia, by mechanically removing their (predominantly) middle cerebral artery clots by using a new retrieval device that had been previously approved by the US Food and Drug Administration for intravascular retrieval of foreign bodies. During a 2-month period, the 6 patients were treated in 5 separate institutions. No patient had an unsuccessful attempt at clot removal. The cases were collected by personal communication with each operator.

Results: In all instances, use of the device resulted in rapid clot removal. Each patient had a large improvement in National Institutes of Health Stroke Scale score. Two of the 6 patients had experienced failure of another clot retrieval device, and 3 patients required no systemic thrombolytics, reducing the likelihood of one of the most feared complications of stroke therapy, intracranial hemorrhage.

Summary: We believe that use of this device may result in improved outcomes for patients with acute ischemic stroke. In our limited experience, it provided a rapid, safe, and effective means for achieving revascularization.

Fig 1.

The jaws of the device, now fully open, protrude through a microcatheter tip. We strongly recommend that potential users lead the microcatheter first to the point of obstruction with a soft guidewire, then exchange the guidewire for the ARD, extending it just beyond the tip of the microcatheter around the thrombus.

Fig 2.

Once the ARD is in position, we gently and smoothly push the catheter forward, slightly closing the jaws of the device over this gelatin-simulated thrombus.

Fig 3.

A, Frontal angiogram from patient 1. The occlusion of the distal M1 segment is apparent and, as will be seen later on the post-treatment frontal image (F), covers the most lateral lenticulostriate artery. B, The magnified frontal working view. Images C–E are made at this working projection. C, We place the microcatheter tip at the point of obstruction. D, The ARD is extended 3 mm beyond the catheter tip E, Both microcatheter and device are withdrawn about 2 cm. Injection of contrast agent shows reperfusion of the distal vessels. F, The pretreatment angiogram (A) can be compared with the posttreatment injection. Because the striate artery was covered, the patient developed a small capsular infarction.