Transtemporal approach through the middle temporal gyrus approach or inferior temporal gyrus approach are particularly suitable for tumors sited at the antero-inferior portion of the trigone and for tumors projecting into the posterior third of the temporal horn.
This route gives the quickest access to the choroidal vessels. In the presence of hydrocephalus or temporal horn entrapment, access and retraction is greatly facilitated.
However there is high risk of injury to the inferior aspect of the optic radiation (causing contralateral quadrantanopia) and to the sensory language cortical center in the dominant hemisphere (causing Wernicke aphasia).
This risk may be decreased by retraction parallel to white matter fibers.