Endoscopic neuroanatomy through the sphenoid sinus

Object: The aim of the study was to perform endoscopic anatomical studies of skull base structures through the sphenoid sinus in order to better understand endoscopic approaches to skull base lesions. Methods: Anatomical studies were performed on six cadavers using sinus endoscopes. The sphenoid sinus was entered via a sublabial nasoseptal approach. Stepwise removal of bone surrounding the sphenoid sinus was done to expose the suprasellar area, the retrosphenoid area and the cavernous sinus. The suprasellar dissection exposed the anterior communicating artery (ACom) complex, optic apparatus, pituitary stalk, lamina terminalis, third ventricle and pituitary gland. The retrosphenoid dissection exposed the mamillary bodies, basilar artery and its branches, the mid-brain, the pons, and the third, fifth, sixth, seventh and eighth cranial nerves. The cavernous sinus dissection exposed the carotid artery, and the third, fourth, fifth and the sixth cranial nerves. Conclusion: Through the sphenoid sinus, most of the structures in the suprasellar area, cavernous sinus and retrosphenoid area can be reached.