Endoscopic Endonasal Approach to Medial and Lateral Parasellar Pituitary Adenomas, Selected Suprasellar Craniopharyngiomas, Meningiomas, and Other Skull Base Lesions

Introduction Direct and angled visualizations in combination with bimanual microsurgical technique in expanded endoscopic endonasal approaches (EEA) introduce the possibility of more controlled and more complete resection of the suprasellar pituitary macroadenomas, craniopharyngiomas, and meningiomas, thus minimizing surgical morbidity.

Aim We present endoscope-assisted transnasal microsurgical techniques for safe and effective entering into the parasellar and suprasellar spaces.

Material and Methods The parasellar space is further divided more precisely into ventral, dorsal, posterior, anterior, and lateral compartments. The first three compartments can be approached by transellar route (from sella out); the lateral compartment can be entered from transsphenoidal extrasellar direction only by dividing the proximal dural ring and mobilizing (medializing) the anterior loop of ICA-CS. Our technique and results in more than 20 cases of parasellar adenomas are presented in detail.

We present eight cases of midline craniopharyngiomas, with average diameter of 23 mm (16–34 mm), and seven suprasellar meningiomas (15–35 mm). Transplanum transtuberculum approach enables bilateral entrance into optic nerve sheath from medial aspect, which is often invaded by meningiomas.

Results GTR was achieved in 75% of craniopharyngiomas and bilateral visual improvement in 75% of patients. New endocrinopathy, including diabetes insipidus, appeared in five out of eight patients (62.5%). Stalk was preserved in four patients, resulting in normal endocrine status in two, partial hypopituitarism in one, and panhypopituitarism in one. Five out of eight patients retained previous quality of life (62.5%). CSF leak followed by meningitis and VP shunting followed in two patients. GTR in meningiomas was achieved in six out of seven patients, new visual field problems in two out of seven, and delayed CSF leak in three out of seven, and no new endocrinopathy appeared. There was no loss of vision and no postoperative diplopia. There was no permanent diplopia in parasellar adenomas.

Conclusions Midline craniopharyngiomas or suprasellar meningiomas of small to moderate size are suitable for transplanum transtuberculum removal if they do not cross the lateral margins of both ICAs. Our results are comparable to the recent series of patients with supradiaphragmatic craniopharyngiomas, removed by EEA, except for the higher incidence of new endocrinopathy (more transinfundibular cases). Pituitary function preservation is more likely in meningiomas than craniopharyngiomas. CSF rate decreased significantly after introduction of gasket technique and Hadad flaps.

Keywords endonasal endoscopic surgery; parasellar adenoma; suprasellar meningioma; craniopharyngioma