Common cochlear artery

The common cochlear artery (Cochlear artery; Cochlear branch of the labyrinthine artery) is one of the two main terminal branches of the labyrinthine artery (internal auditory artery), which itself most commonly arises from the anterior inferior cerebellar artery (AICA) in approximately 75-89% of cases, or less frequently directly from the basilar artery.

Origin and course

The labyrinthine artery enters the internal auditory meatus alongside the facial (CN VII) and vestibulocochlear (CN VIII) nerves, where it divides into two principal branches: the anterior vestibular artery and the common cochlear artery. The common cochlear artery courses along the anterior aspect of the cochlear nerve and enters the cochlea through the modiolus via the cribriform plate (tractus spiralis foraminosus) at the fundus of the internal auditory canal.

Branches

Once within the modiolus, the common cochlear artery divides into its two terminal branches:

• Spiral modiolar artery (main cochlear artery): The principal vessel supplying the cochlea. It spirals within the modiolus and gives off radiating arterioles that course perpendicularly through the osseous spiral lamina toward the lateral cochlear wall, where they supply the stria vascularis and the capillary network of the spiral ligament. It also gives off branches to the spiral ganglion.

• Proper cochlear artery

• Vestibulocochlear artery (Cochlear-vestibular artery): This branch supplies the basal turn of the cochlea (via a cochlear ramus) and portions of the vestibular apparatus, including the saccule and the posterior semicircular canal.