Endoscopic endonasal transcavernous posterior clinoidectomy with interdural pituitary transposition

OBJECT.: The object of this paper was to describe the surgical anatomy and technical nuances of the endonasal transcavernous posterior clinoidectomy approach with interdural pituitary transposition and to report the clinical outcome of this technical modification.The surgical anatomy of the proposed approach was studied in 10 colored silicon-injected anatomical specimens. The medical records of 12 patients that underwent removal of the posterior clinoid(s) with this technique were reviewed.The natural anatomical corridor provided by the cavernous sinus is used to get access to the posterior clinoid by mobilizing the pituitary gland in an interdural fashion. The medial wall of the cavernous sinus is preserved intact and attached to the gland during its medial and superior mobilization. This provides protection to the gland, allowing for preservation of its venous drainage pathways. The inferior hypophyseal artery is transected to facilitate the manipulation of the medial wall of the cavernous sinus and pituitary gland. This approach was successfully performed in all patients, including 6 with chordomas, 5 with petroclival meningiomas, and 1 with an epidermoid tumor. No patient in this series had neurovascular injury related to the posterior clinoidectomy. There were no instances of permanent hypopituitarism or diabetes insipidus.The authors introduce a surgical variant of the endoscopic endonasal posterior clinoidectomy approach that does not require intradural pituitary transposition and is more effective than the purely extradural approach. The endoscopic endonasal transcavernous approach facilitates the removal of prominent posterior clinoids increasing the working space at the lateral recess of the interpeduncular cistern, while preserving the pituitary function.