Potential roles for early revascularization in patients with acute cerebral ischemia

Based on the results of our experience and other available data, we think that patients with stroke in evolution and mild to moderate neurological impairment due to atherosclerotic disease producing internal carotid occlusion or internal carotid siphon stenosis in whom CT scan demonstrates no areas of low density should be offered a revascularization procedure regardless of the duration of symptoms. Because of concern about provoking a disabling occlusion in patients with stroke in evolution due to middle cerebral artery stenosis, we usually recommend anticoagulation as the initial therapeutic modality (26). If the neurological deficit remains unstable or progresses despite anticoagulation, revascularization is performed. In patients with symptomatic delayed cerebral ischemia following subarachnoid hemorrhage, we continue to investigate the potential role of EC-IC bypass. Based on this preliminary experience, we feel optimistic that management morbidity may be improved by performing bypass in the setting of severe proximal spasm of the internal carotid or middle cerebral artery with poststenotic dilatation of the distal middle cerebral tree. Patients whose medical management has failed or in whom aggressive induced hypervolemia and hypertension are contraindicated due to the presence of unsecured aneurysms or underlying cardiovascular disease appear to be the best candidates. The actual efficacy of this procedure in altering the natural history of these admittedly diverse processes is impossible to verify. However, its relative safety will, we hope, prompt increasing willingness on the part of neurologists and neurosurgeons to evaluate the patient with potentially reversible cerebral ischemia and to consider the use of the bypass procedure in those with the appropriate angiographic and clinical profiles. We hope that rCBF measurements with pharmacological manipulations using ¹³³Xe inhalation and single photon emission tomography may significantly improve our ability to select those patients most likely to harbor regions of potential salvageable ischemic cerebral tissue.