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. 2015 BMJ Publishing Group Ltd.