Endonasal Endoscopic Approaches to Lesions Invading the Cavernous Sinus: Reaching Equipoise

Background: Lesions involving the cavernous sinus (CS) have proven to be surgically challenging due to the deep, complex neurovascular anatomy in this region. Traditional approaches have focused on transcranial “lateral to medial” routes. In this study, we detail our series using an endoscopic endonasal “medial to lateral” route to treat tumors invading the cavernous sinus and evaluate the outcomes of this approach.

Methods: We reviewed a prospective surgical database of patients with invasive cavernous sinus lesions who underwent endoscopic endonasal surgery. Outcomes were compared based on the Knosp-Steiner (KS) classification, and histopathological categories.

Results: This review identified 41 consecutive patients with lesions either arising within or extending into the CS. The mean follow-up was 16 (range, 12–37) months. Pathology included pituitary macroadenoma (57%), meningioma/hemangiopericytoma (17%), chordoma/chondrosarcoma (13%), and miscellaneous other lesions (metastatic adenocarcinoma, lymphoma, etc.) (13%). The surgical approach was transsphenoidal transsellar in 31 patients (76%), transethmoidal parasellar in 4 (10%), and transmaxillary transpterygoid in 6 (14%). Average degree of CS resection varied significantly by KS class (KS1-2, 62% vs. KS3-4, 41%; P = 0.04). Gross total CS resection was achieved in 47% of medial (KS1-2) as opposed to 21% of lateral (KS3-4) lesions (P = 0.05). The recurrence rate for KS 1-2 lesions was also significantly lower than those with KS 3-4 status (10% vs. 43%, P = 0.02). Extent of resection was highest for chordoma/chondrosarcoma (72%) followed by pituitary adenoma (55%) and meningioma (40%). Two patients with preoperative cranial neuropathy improved, and one remained stable. Complications included new postoperative cranial neuropathy (2.5%) and CSF leak (2.5%).

Conclusions: The endoscopic endonasal approach provides a useful and safe medial to lateral approach particularly to the medial compartment of the CS. Although certain tumors can also be removed from the lateral CS, based on the consistency, site of origin of the tumor, and the risk to the patient, lateral to medial approaches or radiosurgery may be required to control tumor growth in the lateral CS.