Three small ( 150 participants each) single-center RCTs have compared GA with CS during acute stroke endovascular procedures. All failed to show superiority of GA for the primary end point (2 clinical, 1 DW-MRI infarct growth), whereas 2 of the 3 showed better outcomes for GA for some of the many secondary clinical end points.199 201 Until further data are available, either method of procedural sedation for acute stroke endovascular procedures is reasonable. See Tables XLVI and XLVII in online Data Supplement 1. The use of a proximal balloon guide catheter or a large-bore distal-access catheter, rather than a cervical guide catheter alone, in conjunction with stent retrievers may be beneficial. IIa C-LD Recommendation and COR unchanged from 2015 Endovascular. LOE amended to conform with ACC/AHA 2015 Recommendation Classification System. Treatment of tandem occlusions (both extracranial and intracranial occlusions) when performing mechanical thrombectomy may be reasonable. IIb B-R Recommendation revised from 2015 Endovascular. Tandem occlusions were included in recent endovascular trials that showed benefit of mechanical thrombectomy over medical management alone. In the HERMES meta-analysis, 122 of 1254 tandem occlusions (RR, 1.81 [95% CI, 0.96 3.4]) and 1132 of 1254 nontandem occlusions (RR, 1.71 [95% CI, 1.40 2.09]) were reported compared with medical occlusions (RR, 1.34 [95% CI, 0.87 2.07]) were treated compared with IV alteplase alone.109 In HERMES, there is heterogeneity of treatment methods directed to the proximal extracranial carotid occlusion (no revascularization of the proximal lesion versus angioplasty versus stenting). A retrospective analysis of pooled data from 18 centers examined 395 patients with AIS caused by tandem lesion of the anterior circulation who underwent mechanical thrombectomy (TITAN [Thrombectomy in Tandem Lesions]). mTICI grade 2b/3 was achieved in 76.7% of patients. 