Blood oxygenation level-dependent functional MRI cerebrovascular reactivity (BOLD-CVR) is a contemporary technique to assess brain tissue hemodynamic changes after extracranial- intracranial (EC-IC) bypass flow augmentation surgery. The authors conducted a preliminary study to investigate the feasibility and safety of intraoperative 3-T MRI BOLD-CVR after EC-IC bypass flow augmentation surgery. Five consecutive patients selected for EC-IC bypass revascularization underwent an intraoperative BOLD-CVR examination to assess early hemodynamic changes after revascularization and to confirm the safety of this technique. All patients had a normal postoperative course, and none of the patients exhibited complications or radiological alterations related to prolonged anesthesia time. In addition to intraoperative flow measurements of the bypass graft, BOLD-CVR maps added information on the hemodynamic status and changes at the brain tissue level. Intraoperative BOLD-CVR is feasible and safe in patients undergoing EC-IC bypass revascularization. This technique can offer immediate hemodynamic feedback on brain tissue revascularization after bypass flow augmentation surgery.
Keywords: ACA = anterior cerebral artery; BOLD; BOLD = blood oxygen level–dependent; CVR = cerebrovascular reactivity; EC = extracranial; EC-IC bypass; IC = intracranial; ICA = internal carotid artery; ICG = indocyanine green; MCA = middle cerebral artery; NIHSS = National Institutes of Health Stroke Scale; STA = superficial temporal artery; cerebrovascular; functional MRI; mRS = modified Rankin Scale; steno-occlusive disease.