Computed tomography angiographic anatomical features for successful transbrachial insertion of a balloon guide catheter for mechanical thrombectomy in acute ischemic stroke

When the femoral approach for mechanical thrombectomy (MT) in acute ischemic stroke (AIS) is limited, trans-brachial or-radial access is an alternative. However, transbrachial insertion of a 9Fr (outer diameter [OD]) balloon guide catheter (BGC) into the carotid artery is not feasible. Computed tomographic (CT) angiography (CTA) may provide vascular anatomical information for successful insertion. We investigated CTA anatomical features for successful transbrachial insertion of a 9Fr BGC into the carotid artery.We analyzed AIS patients who underwent CTA and transbrachial MT using a 9Fr BGC between 2014 and 2016. We evaluated the successful insertion rate and CT angiographic anatomical features.Twenty-four patients met our inclusion criteria. We achieved successful insertion in 18 (75%) of 24 cases: 7 (58.3%) of 12 for left carotid arteries and 11 (91.7%) of 12 for right carotid arteries. Successful insertion was achieved in 4 of 4 bovine aortic arch for left carotid occlusion and in 3 of 8 nonbovine aortic arches for left carotid occlusion. We achieved successful insertion in 3 nonbovine cases with takeoff angles ≥23° and failed insertion in 5 cases with takeoff angles23°. We achieved successful insertion in 10 of the 10 cases with takeoff angles ≥25° in the right common carotid artery. The BGC was broken in 1 of 2 cases with takeoff angles25°.The CTA provided a high likelihood of successful 9Fr OD BGC insertion without an introducer sheath. Successful transbrachial insertion was achieved in bovine left carotid cases, in nonbovine left carotid cases with takeoff angles ≥23°, and in right carotid cases with takeoff angles ≥25°.