**Abstract**

The cavernous sinus is a very complex area, and surgical treatment requires detailed anatomical knowledge and familiarity with its relationship to surrounding structures. By exposing the lateral wall of the cavernous sinus with the extradural approach, it is possible to pass through the triangular corridor of the cavernous sinus and perform surgical treatment for diseases such as trigeminal schwannoma and meningioma inside and outside the cavernous sinus. In addition to the extradural infratemporal fossa approach, the extradural infratemporal fossa to the pterygoid fossa and the approach to the paranasal sinuses can be safely performed by inserting the endoscope into the bone corridor of the middle cranial fossa. Furthermore, in the last decade, transnasal endoscopic skull based approaches have further developed, facilitating surgical access to the cavernous sinus. The cavernous sinus is an unattachable site due to the complex structure of multiple nerves, veins, and internal carotid arteries, but if the anatomy of the cavernous sinus is known well we can treat this complex site. As for the choice of approach to the cavernous sinus, a better understanding of the anatomy surrounding the cavernous sinus will allow a rational choice between transcranial and transnasal approaches.

**Keywords:** cavernous sinus, middle fossa approach, endoscopic approach
