Main corridors in the transphenoidal skull base surgery

Sphenoid sinus is very close to important and vulnerable structures of the skull base and therefore a delayed diagnosis and treatment can be potentially lethal. Endoscopic sinus surgery is a safe and effective technique that allows a direct route to the sphenoid sinus and therefore is considered the gold standard for the surgical approach to this region. Over the years, the indications for transnasal approaches in skull base surgery have extended in order to obtain an adequate resection of the pathology as with other conventional approaches, with a minor morbidity and an equal efficiency. Many classifications, divided in base of intracranial pathology or intracranial anatomical landmarks, have been proposed to define the transnasal corridors in base of the localization through the middle cranial base. In this chapter, we propose a review of classification of transsphenoidal skull base approaches and show the main transnasal corridors to the sphenoid sinus based on the anatomical sphenoidal target and extension of pathology.