Endoscopic approaches to the cavernous sinus

Abstract

Skull base tumors that involve the cavernous sinus (CS) present a challenge to the endoscopic surgeon. Most such lesions arise from sellar pathology that involves the medial wall of the CS, which can be accessed by a transsphenoidal transsellar approach. Tumors that arise primarily in the medial CS may be accessed via a transethmoidal transsphenoidal parasellar approach, which avoids the dissection of sellar contents but requires the removal of bone overlying the carotid artery. Involvement of the tumor in the lateral CS may be accessed by a transmaxillary transpterygoid approach in patients who wish to avoid a craniotomy and in whom radiosurgery is not an option. These tumors are associated with a greater risk of cranial nerve injury, including extraocular palsy. Important adjuncts to the endoscopic approach include angled instrumentation, neuronavigation, intraoperative Doppler and intrathecal fluorescein injection. Tumor extirpation from the CS and cytoreduction are realistic goals for the endoscopic surgeon in well-selected cases. Skull base tumors that involve the cavernous sinus (CS) present a challenge to the endoscopic surgeon. Most such lesions arise from sellar pathology that involves the medial wall of the CS, which can be accessed by a transsphenoidal transsellar approach. Tumors that arise primarily in the medial CS may be accessed via a transethmoidal transsphenoidal parasellar approach, which avoids the dissection of sellar contents but requires the removal of bone overlying the carotid artery. Involvement of the tumor in the lateral CS may be accessed by a transmaxillary transpterygoid approach in patients who wish to avoid a craniotomy and in whom radiosurgery is not an option. These tumors are associated with a greater risk of cranial nerve injury, including extraocular palsy. Important adjuncts to the endoscopic approach include angled instrumentation, neuronavigation, intraoperative Doppler and intrathecal fluorescein injection. Tumor extirpation from the CS and cytoreduction are realistic goals for the endoscopic surgeon in well-selected cases.