Endoscopic endonasal approaches to the cavernous sinus: Surgical approaches

OBJECTIVE: After completion of an earlier endoscopic transsphenoidal anatom ic study, we studied various endoscopic transsphenoidal approaches using ca daveric specimens to develop endoscopic endonasal surgical approaches to th e cavernous sinus. METHODS: Ten cavernous sinuses in five artery-injected adult cadaveric head s were studied with 0-, 30-, and 70-degree angled 4-mm rod-lens endoscopes. The extent of the surgical exposure, the skewed endoscopic anatomic view, and the maneuverability of surgical instruments through their relative oper ating spaces were studied after various endoscopic endonasal approaches via one nostril. RESULTS: The paraseptal approach was used between the nasal septum and the middle turbinate and provided exposure at the anteromedial portion of the c avernous sinus. The contralateral paraseptal approach rendered a slightly m ore medial view at the cavernous sinus than did the ipsilateral approach. T his approach offered limited surgical access to the lateral vertical compar tment. The middle turbinectomy approach allowed surgical access to the late ral wall of the cavernous sinus, except for the superior orbital fissure an d the orbital apex. The middle meatal approach, which was made between the middle turbinate and the lateral nasal wall, revealed the entire lateral ve rtical compartment of the cavernous sinus, including the orbital apex and t he superior orbital fissure. However, its lateral tangential surgical traje ctory and the absence of dedicated surgical tools limited the surgeon's sur gical maneuverability. A combination of the middle turbinectomy and middle meatal approaches increased the operating space. CONCLUSION: Various endoscopic endonasal surgical approaches to the caverno us sinus were studied using adult cadaveric head specimens.