Posterior Petrous Meningioma Fed by a Branch of the Persistent Trigeminal Artery Terminating in the Anterior Inferior Cerebellar Artery.

Abstract

Persistent trigeminal artery (PTA) is the most common persistent carotid-basilar fetal anastomosis and terminates extremely rarely directly in the dominant hemispheric branch of the anterior inferior cerebellar artery (AICA). We present a case of a branch of this PTA variant (Saltzman type 3b) demonstrated as the feeding artery of a large posterior petrous meningioma, which was confirmed under direct vision during surgery through the extended retrosigmoid approach. Meticulous dissection from the tumor surface provided early identification of the feeding branch from the PTA and its bifurcation at the attachment of the posterior petrous surface adjacent to the jugular foramen enabled preservation of the terminal cortical branch of the cerebellar hemisphere. Meningioma in the posterior cranial fossa may recruit substantial supply from branches of the PTA terminating in the AICA. This PTA variant should be recognized during surgical resection of posterior fossa neoplasms to prevent ischemic complication of the AICA territory.