Subtemporal approach: Intra- and extradural approach, anterior petrosal approach, and endonasal approach

The subtemporal approach is applied to the middle cranial fossa and infratemporal fossa in addition to the tentorial incisura, petroclivus, and brain stem lesions. To minimize compression damage to the temporal lobe, it is essential to perform the craniotomy along the middle cranial fossa, to remove the zygomatic arch for supratentorial lesions, and to remove the petrous pyramid for infratentorial lesions. To avoid venous damage, the drainage pathways of the superficial sylvian vein and bridging veins, including Labbé’s vein, should be preoperatively evaluated. Furthermore, with the recent advances in endoscopic surgery, it has become possible to approach the middle cranial fossa and infratemporal fossa endonasally. In the endonasal approach, surgical simulation is important because of the variations in the nasal cavity and paranasal sinus structures. In this article, we outline the surgical anatomy of the middle cranial fossa required for the subtemporal approach, including the endonasal approach, and variations in the venous drainage of the superficial sylvian vein and petrosal vein. Moreover, we describe the treatment of pontine lesions by the subdural subtemporal approach, Meckel cave lesions by the epidural subtemporal approach, petroclival lesions by the anterior transpetrosal approach, and infratemporal lesions by the endonasal approach.