Endoscopic endonasal dissection of the pterygopalatine fossa, infratemporal fossa, and post-styloid compartment. Anatomical relationships and importance of eustachian tube in the endoscopic skull base surgery.

treatment of skull base disorders and is routinely used in some centers for the treatment of neoplastic and non-neoplastic cranial base pathology. The group of minimally invasive endoscopic techniques used to approach the cranial base are also known as expanded endoscopic approaches (EEA), which are classified in a modular fashion under two main categories: sagittal (or cranio-caudal) and coronal (or medio-lateral). Figure 1