Concentric Retriever Device (CRD) in Acute Ischemic Stroke

The primary objective is to assess the safety and efficacy of the Concentric Retriever in the treatment of thrombotic occlusions originating in the internal carotid, middle cerebral (M1 and M2 segments), basilar, posterior cerebral or vertebral arteries. A maximum of 50 patients may be enrolled at a single site, University of California, Los Angeles. Primary endpoints: Achievement of recanalization (TIMI/TICI grade II or III flow) immediately post procedure without occurrence of major complications will be assessed. Major complications are defined as vessel perforation, intramural arterial dissection, symptomatic intra-cranial hemorrhage, and significant embolization in a previously uninvolved arterial territory. Secondary endpoints: Assessment of patient's neurological condition and functional state using the NIHSS, Barthel Index, and Modified Rankin at 30 and 90 days post-procedure. A composite of major adverse events at 30 and 90 days post-procedure will be reported. Major adverse events are defined as death and new stroke.