Vertebrobasilar dolicho- ectasia is associated with traditional ischemic stroke risk factors such as increasing age, hypertension, and male sex. However, its relationship to atherosclerotic disease is less clear.765 767 Although many patients may be asymptomatic, others may present with a variety of CLINICAL STATEMENTS AND GUIDELINES Kleindorfer clinical syndromes, including cranial nerve or brainstem compression, obstructive hydrocephalus, subarachnoid hemorrhage, and ischemia.760,764,768 Ischemic events may be related to thromboembolic phenomenon but may also result from the disruption of small perforat- Asymptomatic patients have the most whereas those presenting with compressive symptoms or demonstrating progressive enlargement have a worse prognosis.760,768,770 The rate of recurrent ischemic stroke may be quite high,761,771,772 with 1 study reporting a rate of 19% at just under 2 Increasing basilar artery diameter, diffuse intracranial dolichoectasia, and associated ischemic heart disease increased the risk of recurrent events.761 Many patients with vertebrobasilar dolichoectasia are treated medically with antithrombotic medication, but high-quality evidence on the management strategies for patients with vertebrobasilar dolichoectasia, par- ticularly in the setting of a prior ischemic stroke or TIA, is lacking. Several case series describe endovas- and various surgical interven- ; however, there is little evidence that such treatments reduce the risk of additional ischemic events in patients who present with an ischemic stroke or TIA. The literature on dolichoectasia of the anterior circulation in patients with prior ischemic stroke or TIA is even more sparse; therefore, this topic is not addressed in this guideline. Recommendation-Specific Supportive Text 1. There are no prospective RCTs comparing anti- thrombotic therapies with observation alone. However, case series tend to suggest that anti- thrombotic therapy lowers the risk of recurrent ischemic events compared with the natural his- There are also no prospective RCTs comparing antiplatelet strategies (either aspirin or second-generation antiplatelet drugs) with anticoagulation. 