inferolateral trunk

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The inferolateral trunk, along with the meningohypophyseal trunk, is a branch of the C4 segment of the internal carotid artery. It is identified in up to 80% of dissection specimens but is less frequently seen on imaging.

It is also referred to as the artery to the inferior cavernous sinus, arising laterally from the cavernous segment and is directed inferiorly (thus inferolateral trunk).

The inferolateral trunk has three or four branches, as it passes between the trochlear nerve (CN IV) (below) and ophthalmic division of the trigeminal nerve (CN V) (above):

first branch runs posteriorly along the abducens nerve (CN VI) and supplies part of the tentorium. The marginal tentorial artery (usually from the meningohypophyseal trunk) may arise from here
second branch to the superior orbital fissure (directed anteriorly) anastomoses with the deep recurrent meningeal branch of the ophthalmic artery (this is an important consideration during embolization)
third branch is given off as the artery passes of the ophthalmic division and supplies the maxillary division of the trigeminal nerve as it exits through foramen rotundum. (this is the most frequently seen branch on angiography)
fourth branch anastomoses with the accessory meningeal artery which passes through foramen ovale
fifth branch may be present; the recurrent artery to the foramen lacerum. It anastomoses with a carotid branch from the ascending pharyngeal artery