Using a low-metal–density stent for thrombectomy-resistant vertebrobasilar occlusion due to thrombus migration from a thrombosed vertebral artery aneurysm: illustrative case

BACKGROUND: Thrombosed intracranial aneurysms can lead to large vessel occlusion as a result of spontaneous thrombosis. Although mechanical thrombectomy is likely effective, recurrent thromboembolism can occur if the thrombotic source remains untreated. The authors describe a case of recurrent vertebrobasilar artery occlusion due to thrombus migration from a large thrombosed vertebral artery (VA) aneurysm that was successfully treated with mechanical thrombectomy followed by stenting. OBSERVATIONS: A 61-year-old male previously diagnosed with a large, thrombosed VA aneurysm presented with right hypoesthesia. Imaging on admission showed left VA occlusion and an acute ischemic lesion in the left medial medulla. His symptoms worsened, with complete right hemiparesis and tongue deviation occurring 3 hours after admission, and mechanical thrombectomy was performed to recanalize the left-dominant VA. Despite several attempts, reocclusion of the vertebrobasilar system occurred after each mechanical thrombectomy because of repeated thrombus formation in the thrombosed aneurysm. Therefore, a low-metal–density stent was deployed to prevent thrombus migration into the parent artery, which resulted in complete recanalization and rapid improvement of the symptoms. LESSONS: Stenting with a low-metal–density stent for recurrent embolism secondary to thrombus migration from a large thrombosed aneurysm was feasible in the acute stroke setting.