[Implementation of Penumbra-assisted Half-Stent Thrombectomy for Patients with Acute M2 Occlusion:Results of Initial Experiences].

The benefits of mechanical thrombectomy(MT)for acute M2 occlusion have remained unclear because of unavoidable device-related complications due to vascular morphological characteristics. We developed a Penumbra-assisted half-stent thrombectomy for achieving secure retrieval of thrombus with minimal damage to the small-caliber vessel. In total, 6 patients were treated with MT for acute M2 occlusion using this technique between November 2016 and May 2017, including 3 men and 3 women, mean age 74.8(51-98)years. The mean baseline National Institutes of Health Stroke Scale score was 17.5(6-32), and Alberta Stroke Program Early Computed Tomography Score-Diffusion-Weighted Imaging was 7.5(6-9). After navigation of the microcatheter through the thrombus in M2 supported by a Penumbra 4MAX as a distal access catheter, the stent retriever(SR)was partially deployed to cover the entire thrombus. The 4MAX was then advanced towards the caudal end of the thrombus, and the SR was pulled back into the 4MAX with simultaneous aspiration of the 4MAX. We used the Trevo XP3 in 5 patients and Revive SE in 1 patient. The mean procedure time from groin puncture to recanalization was 60(54-66)min. Successful recanalization(Thrombolysis in Cerebral Infarction score 2b or 3)was achieved in 5(83%)patients. There were no cases of symptomatic intracranial hemorrhage. Good outcome(modified Rankin Scale score 0 to 2)at 3 months was achieved in 3(50%)patients. Penumbra-assisted half-stent thrombectomy appears to be an effective alternative strategy in MT for acute M2 occlusion.