TRANSMAXILLOSPHENOIDAL APPROACH TO TUMORS INVADING THE MEDIAL COMPARTMENT OF THE CAVERNOUS SINUS

A transmaxillosphenoidal approach was used to remove sellar tumors inv ading the cavernous sinus. This procedure, a widening of the standard transsphenoidal approach to the sella turcica, uses the sublabial or t ransnasal route in which the medial wall of the maxillary sinus is lat erally dislocated. This method provides good exposure of the prominenc es of bone above the carotid artery which lies on the posterolateral w all of the sphenoid sinus. This bone area is the key to opening the ca vernous sinus inferomedially and removing lesions within its medial co mpartment. The inferomedial approach takes an entirely extracerebral r oute so that tumors invading the cavernous sinus through its medial wa ll are approached inferomedially following the direction of tumor grow th. It also allows direct visualization of the intracavernous carotid artery during tumor removal, thus sparing the cranial nerves, which ru n on the opposite side. Adequate surgical exposure of a pituitary aden oma is achieved with a custom-made sphenoidal retractor with asymmetri c blades, the shorter blade holding aside the thin medial wall of the maxillary sinus. Between October, 1989, and July, 1993, 11 patients wi th tumors invading the cavernous sinus underwent surgery via this appr oach; 10 had pituitary adenomas and one had a craniopharyngioma. Eight tumors were treated by primary operation: four tumors were totally an d four subtotally (> 80%) removed; one tumor already operated on elsew here was totally removed; and of two tumors already operated on and ir radiated, one was subtotally removed and the other only partially (app roximately 40%) removed owing to marked postirradiation scarring. None of the patients suffered permanent cranial nerve deficit and all but one showed marked clinical improvement.