Therapeutic Results of a Direct Aspiration First Pass Technique Using the Penumbra 4MAX Aspiration Catheter for Middle Cerebral Artery M2 Occlusion

Objective: While the effectiveness of thrombectomy for anterior circulation proximal intracranial arterial occlusions has been established, there is no solid evidence concerning its therapeutic effect on acute ischemic stroke due to middle cerebral artery M2 occlusion. In this study, we evaluated the efficacy and safety of a direct aspiration first pass technique (ADAPT) using the Penumbra 4MAX aspiration catheters (4MAX; Medico’s Hirata Inc., Osaka, Japan) for M2 occlusion. Methods: Of the 17 patients with acute ischemic stroke who underwent thrombectomy for M2 occlusion between January 2016 and December 2017 at our institution, 12 patients in whom ADAPT using the 4MAX was performed as the first-line procedure were evaluated. The stent retriever (SR) was used concomitantly in patients in whom recanalization could not be achieved by ADAPT using the 4MAX only. The retrospective evaluation was performed according to effective recanalization (thrombolysis in cerebral infarction [TICI] scale 2b-3) and independence in daily activities (modified Rankin Scale [mRS] score 0-2 after 3 months) as the efficacy endpoints and symptomatic intracranial hemorrhage as a safety endpoint. Results: The median age of the 12 subjects was 77 (interquartile range [IQR] 69–80) years, 9 (75.0%) were males, and the median preprocedural National Institutes of Health Stroke Scale (NIHSS) score was 19.5 (IQR: 16–24.5). The 4MAX reached the clot in 11 (91.7%), and effective recanalization was obtained by ADAPT alone in 8 (66.7%). Effective recanalization was achieved in 11 (91.7%) at the end of all procedures, the outcome was favorable in 8 (66.7%), and no symptomatic intracranial hemorrhage was observed. Conclusion: In M2 occluded region, a high recanalization rate could be achieved by ADAPT using the 4MAX without causing symptomatic intracranial hemorrhage, and the results suggested high efficacy and safety of the technique.