Imaging Review of the Endoscopic Operative Corridor for Clivus Lesions

Traditional transcranial approaches for lesions involving the clivus, in particular skull base chordoma have several disadvantages for midline skull base lesions as compared to the endoscopic endonasal approach (EEA), such as higher morbidity and lesser extent of resection. These disadvantages led to the development of endoscopic skull-base approaches to access pathology that involves the anterior cranial fossa, central skull base, and lower skull base lesions. In particular, lesions of the clivus are well suited for EEA. Surgical access of the clivus falls into 2 stages: the endonasal approach for access, and the endonasal resection of tumor. The objective of this article is to review the anatomy along the operative corridor for the purpose of image interpretation in preoperative planning in the context of EEA. We provide an imaging review of the sinonasal anatomy used for access by otolaryngologists and the anatomy of the clivus used by neurosurgeons for preoperative planning and resection.