Microsurgical division of an arteriovenous fistula within the sylvan fissure

This is part of a series of teaching videos for medical students and neurosurgery trainees at Queens Hospital, Romford, UK. Pial arteriovenous fistulae are rare neurovascular lesions characterised by a single or multiple arteries directly shunting into a cortical vein without the presence of a nidus. The arteries are not durally based, instead they are branches that fistulate with the vein via the pia. This is an unusual case of a patient presenting with otalgia associated with a pulsatile tinnitus. MRI and angiography revealed a Cognard grade IV AVF within the sylvan fissure with a high risk of intracranial haemorrhage. This video describes the history, imaging findings, treatment options and description of the surgery and anatomy.