Endoscopic transsphenoidal resection of pituitary adenomas invading the cavernous sinus

Abstract Pituitary adenomas are benign growths that invade the cavernous sinus (CS) in 10-15% of cases. There are different types of microsurgical and endoscopic approaches enabling resection of tumors from the CS cavity that is a relatively small and hard to reach anatomical structure comprising eloquent neurovascular structures. A study group included 97 patients with pituitary adenomas (PAs) invading the CS. PAs were resected using an endoscopic technique: adenomas were resected from the CS cavity through a standard endoscopic endonasal transsphenoidal approach in 62 cases; a lateral extended transsphenoidal endoscopic approach was used in 35 cases. A control group included patients with PAs spreading into the laterosellar region who were operated on using microsurgical extra-intradural (n=14) and transsphenoidal (n=149) approaches. In the study group, the degree of PA invasion into the CS cavity was determined using the Knosp scale. In the study group, total tumor resection was achieved in 49 (50.5%) cases, subtotal resection in 39 (40.2%) cases, and partial resection in 9 (9.3%) patients. In the case of visual disorders (n=70), vision improvement was achieved in 41.4% of cases. Vision deterioration was detected in 11.4% of cases; no vision changes were in 47.1% of cases. Patients (27.8%) who had not had visual impairments before surgery had no negative changes in vision in the postoperative period. The development/augmentation of oculomotor disorders in the study group occurred in 14 (14.4%) cases. In the study group, hormonal remission of the disease in patients with hormone-active PAs was in 26.7% of cases (n=12). There were no cases of nasal liquorrhea, meningitis, and death in the study group. Endoscopic endonasal transsphenoidal resection of PAs invading the CS is a more efficient and safer surgical technique compared to microsurgical techniques (transsphenoidal and extra-intradural approach). The lateral extended transsphenoidal endoscopic approach enables resection of PAs with massive invasion into the CS (Grade III and Grade IV, Knosp scale) and has less postoperative complications compared to the extra-intradural approach (p