Abstract 197: Mechanical Thrombectomy Of Basilar Artery Occlusion On A Hypoplastic Vertebrobasilar Circulation

Abstract

Introduction Basilar artery occlusion (BAO) is one of the most severe acute ischemic strokes which carries high mortality and morbidity risk. Mechanical thrombectomy (MT) has been used as a promising treatment for BAO. However, the vertebral‐basilar anatomy is more challenging for MT compared to the anterior circulation due to several congenital variants such as hypoplastic vertebral artery, fenestration on the vertebrobasilar junction, or chronic asymptomatic occlusions of vertebral arteries, and tortuous subclavian arteries and vertebral arteries (VAs). Here, we described a BAO case with hypoplastic vertebrobasilar arteries, which was successfully treated with thrombectomy using the direct aspiration technique. Methods Electronic Medical Records review of a patient with acute basilar artery occlusion stroke. Results 55‐year‐old healthy gentleman presented to ER with acute onset with confusion, dysarthria, left‐sided weakness, and right facial droop. Initial NIHSS was 12. CT angiography (CTA) head and neck showed basilar artery was occluded in the distal one third segment. Because of the right fetal posterior cerebral artery and prominent left posterior communicating artery, his bilateral VAs and basilar artery were underdeveloped. The left VA appeared to be slightly bigger than the right one. After the patient received IV tPA, he was taken for mechanical thrombectomy. A Ballast catheter was placed in the left subclavian artery near the left VA origin. The conventional angiography showed the left VA was 2.8 mm and proximal basilar was about 2.1 mm. The Zoom 35 aspiration catheter was then used for mechanical thrombectomy. A complete basilar recanalization was achieved on the first pass. The patient improved after the MT. His NIHSS on discharge was 0. Conclusion The benefits of MT on BAO remain unknown despite several clinical trials. One of the reasons is due to more challenged vascular anatomy compared to anterior circulation. Underdevelopment of unilateral VA was commonly seen in posterior circulation ischemic strokes. But the underdevelopment of bilateral VAs with basilar arteries in BAO cases was rare and more difficult to treat. The Zoom 35 aspiration catheter provided a great advantage for this case with its smaller outer diameter, good navigation ability, and great aspiration efficacy. Our experience suggested a direct aspiration first pass technique (ADAPT) has an advantage on BAO, especially in the congenitally underdeveloped vertebrobasilar arteries.