Suggested Indications for Cavernous Sinus Exenteration in Malignant Disease of the Skull Base

Purpose: Cavernous sinus extenteration (CSE) has been described in the treatment of invasive tumors involving the cavernous sinus (CS). However, there has been little discussion or consensus on when it should be performed.

Method: A retrospective analysis at a tertiary skull base center was performed: five patients (three men and two women; age range, 30 to 62 yrs) underwent CSE over a 3-year period for primary malignant tumors involving the skull base with local extension to CS.

Result: CSE was performed in two patients with nasoethmoidal squamous cell carcinoma (SCC) who had initial good response to cytoreductive chemoradiotherapy, two patients as primary treatment (minor salivary gland adenoid cystic carcinoma, and desmoplastic melanoma), and in one after late recurrence of a neurotropic parotid adenoid cystic carcinoma (previous parotid surgery and radiotherapy). CSE involved: craniotomy and orbitozygomatic osteotomy pedicled on masseter; orbital exenteration; drilling of anterior clinoid and skeletonization of II, superior orbital fissure, V2, V3, vidian nerve, and pterygopalatine fossa; division of trigeminal nerve proximally at brainstem; and “unlocking” of CS and en bloc resection of contents with orbital apex and pterygopalatine fossa. Reconstruction was with temporalis in three cases, and with rectus abdominis in the two patients with nasoethmoidal SCC (who also required resection of anterior cranial fossa floor). All were managed with lumber drainage from 48 hours postop. Complications included re-exploration for congested free flap (one) and removal of bone flap for temporal lobe swelling (one). All made a full neurologic recovery and remain alive currently. Three patients underwent postop radiotherapy of which two will be considered for gamma knife boost to CS.

Conclusion: We suggest that CSE should be considered in: (1) neurotropic malignancy such as adenoid cystic carcinoma and desmoplastic melanoma involving a trigeminal nerve division; (2) nasoethmoidal SCC with extension up to CS if there is a good initial chemoradiotherapy response; and (3) where unlocking of the CS is required to maximize resection margins of tumors involving pterygopalatine fossa and orbital apex. Such surgery should be part of a package of adjuvant therapy including radiotherapy and gamma knife boost to CS.