Neurosurg Focus
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The role of cerebral revascularization remains unclear in symptomatic occlusive cerebrovascular disease refractory to medical therapy. Despite the disappointing findings of the Cooperative Study on Extracranial-Intracranial Bypass, a subpopulation of patients with ischemic cerebrovascular disease and poor hemodynamic reserve may benefit from extracranial-intracranial (EC-IC) bypass. The authors reviewed the records of 65 patients who underwent 71 EC-IC bypass procedures at their institution over the past 6 years. ⋯ Although the Cooperative Study failed to show benefit from this treatment modality, the authors have continued to perform EC-IC bypass in certain cases. Carefully selected individuals with occlusive cerebrovascular disease and persistent ischemic symptoms refractory to maximal medical therapy appear to benefit from cerebral revascularization.
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The St. Louis Carotid Occlusion Study demonstrated that ipsilateral increased O2 extraction fraction (OEF) (Stage II hemodynamic failure) measured by positron emission tomography (PET) is a powerful independent risk factor for subsequent stroke in patients with symptomatic complete carotid artery (CA) occlusion. The ipsilateral ischemic stroke rate at 2 years has been shown to be 5.3% in 42 patients with normal OEF and 26.5% in 39 patients with increased OEF (p = 0.004). ⋯ The primary endpoint will be all strokes and death occurring between randomization and the 30-day postoperative cut off (with an equivalent period in the nonsurgical group), as well as subsequent ipsilateral ischemic stroke developing within 2 years. It is estimated that 186 patients will be required in each group. Assuming that 40% of PET scans will demonstrate increased OEF, this will require enrolling 930 clinically eligible individuals.