Fenestration of the supraclinoid internal carotid artery in a patient with a concomitant intracranial arteriovenous malformation.

Accurately recognising a supraclinoid internal carotid artery (ICA) fenestration, despite its rare location, is important as it can mimic an intracranial aneurysm, intraluminal thrombus or focal dissection on non-invasive imaging. The overwhelming majority of reported supraclinoid ICA fenestrations are associated with intracranial aneurysms; however, a concomitant arteriovenous malformation (AVM) remote from the fenestration site should also be considered. We present the case of a 26-year-old woman with a Spetzler-Martin grade I right frontal AVM in whom a left supraclinoid ICA fenestration was incidentally discovered during cerebral angiography. She underwent n-N-Butyl Cyanoacrylate glue embolisation of two dominant middle cerebral artery feeders followed by neurosurgical resection. She tolerated procedures well without complications and has remained neurologically intact.