Since the publication of the 2013 AIS Guidelines, 2 RCTs of sonothrombolysis as adjuvant therapy for IV thrombolysis have shown no clinical benefit. NOR-SASS (Norwegian Sonothrombolysis in Acute Stroke Study) randomized 183 patients who had received either alteplase or tenecteplase for AIS within 4.5 hours of onset to either contrast-enhanced sonothrombolysis (93 patients) or sham (90 patients). Neurological improvement at 24 hours and functional outcome at 90 days were not statistically significantly different in the 2 groups, nor were the rates of sICH.187 CLOTBUST-ER (Combined Lysis of Thrombus With Ultrasound and Systemic Tissue Plasminogen Activator [tPA] for Emergent Revascularization in Acute Ischemic Stroke) randomized 676 patients with AIS (NIHSS score 10) who received IV alteplase within 3 or 4.5 hours of symptom onset and randomly allocated to operator independent sonothrombolysis (335) or sham ultrasound (341).188 Compared with the control arm, the neurological improvement, death, and serious adverse events in the intervention arm were not statistically different. At this time, there are no RCT data to support additional clinical benefit of sonothrombolysis as adjuvant therapy for IV fibrinolysis. See Table XLIV in online Data Supplement 1. 3.7. Mechanical Thrombectomy 3.7.1. Concomitant With IV Alteplase COR LOE New, Revised, or Unchanged Patients eligible for IV alteplase should receive IV alteplase even if mechanical thrombectomy is being considered. I A Recommendation reworded for clarity from 2015 Endovascular. See Table XCV in online Data Supplement 1 for original wording. In patients under consideration for mechanical thrombectomy, observation after IV alteplase to assess for clinical response should not be performed. III: Harm B-R Recommendation revised from 2015 Endovascular. 