Introduction: Giant pituitary adenomas, defined as those greater than 4 cm in diameter, can be surgically formidable lesions. We evaluate our experience with resection of giant pituitary adenomas using the endoscopic transsphenoidal approach.
Methods: Retrospective review of a prospective database of endoscopic skull base procedures performed within a two-year period revealed 7 cases of giant pituitary adenomas. We evaluated each case for tumor size, extent of resection, and postoperative complications.
Results: Seven patients (4 males, 3 females) presented with giant pituitary adenomas with an average size of 4.5 in greatest diameter (range: 4.1 cm to 7.2 cm). Gross-total resection was achieved in 3 cases, where the tumors were less than 5 cm without any cavernous sinus invasion. Subtotal resection was achieved in 4 cases because of cavernous sinus invasion and tumor adherence to optic nerves, hypothalamus and cerebral arteries. An extended transplanum approach was performed in 2 patients because of significant suprasellar extension. All patients experienced visual improvement postoperatively. Complications included postoperative apoplexy in two patients, transient diplopia in one, and permanent diabetes insipidus in one. Nasoseptal flap reconstruction was used in all cases, and there were no postoperative CSF leaks.
Conclusions: The endoscopic endonasal transsphenoidal approach provides excellent exposure for resection of giant pituitary adenomas with a wide-angle field of view. Tumors with considerable suprasellar extension may require a transplanum transtuberculum approach for better access. Gross-total resection is limited by cavernous sinus invasion and tumor adherence to critical neurovascular structures. Postoperative residual tumor may pose a risk for postoperative pituitary apoplexy.
Patient Care: Our research suggests that, in experienced hands, the endoscopic transsphenoidal approach may provide an effective alternative in the treatment of giant pituitary adenomas, greater than 4 cm in diameter, in select patients.
Learning Objectives: By the conclusion of this session, participants should be able to: 1) Understand the indications for using the endoscopic transsphenoidal approach for removal of giant pituitary adenomas, 2) Describe the advantages of endoscopic transsphenoidal approach in treatment of these lesions, and 3) Understand the limitations of achieving gross total resection in these particular cases