The Occipital Artery as an Alternative Donor for Low-Flow Bypass to Anterior Circulation After Internal Carotid Artery Occlusion Failure prior to Exenteration for an Atypical Cavernous Sinus Meningioma

BACKGROUND: In skull base tumors involving the cavernous sinus, indications for aggressive resection are sparse and must be carefully examined because of their invasiveness. With careful evaluation, techniques including internal carotid artery sacrifice with or without extracranial-intracranial bypass may still be an option in some cases. Moreover, previous surgery with the sacrifice of potential donor vessels requires adjusting the revascularization strategy. We describe an occipital artery-middle cerebral artery bypass before skull base tumor resection. CASE DESCRIPTION: A 47-year-old woman with a recurrent cavernous sinus meningioma was referred to our department. Because of tumor recurrence after radiotherapy and its rapid progression, radical resection, including part of the cavernous sinus, was planned. A balloon test occlusion was performed and showed good tolerance. An endovascular internal carotid artery occlusion was performed. The patient eventually experienced motor deficits and aphasia after surgery. Therefore, bypass surgery using an occipital arteryemiddle cerebral artery anastomosis was performed. The patient showed no exacerbation of symptoms after bypass surgery and subsequently underwent tumor resection. CONCLUSIONS: The reliability of balloon test occlusion in the management of giant aneurysms may not be similarly applicable to skull base tumors. If hypoperfusion symptoms occur after occlusion of the internal carotid artery, a surgical revascularization procedure should be considered because of the risk of ischemic stroke following tumor resection. For patients whose superficial temporal artery is not available, the occipital artery can be a valuable alternative donor for low-flow bypass.