[Transnasal endoscopic anatomy of the clivus and approaches consideration]

In-depth understanding of endoscopic anatomy of the skull base is the cornerstone of the development of endoscopic endonasal skull base surgery. The purpose of this study is to explore the anatomical landmarks of the clivus for endoscopic endonasal skull base surgery.

Eight silicon-injected adult cadaveric heads (16 sides) were dissected performing endoscopic endonasal approach. The clivus and adjacent structures were exposed; and their anatomy shown in detail. High-quality pictures were produced.

The clivus was subdivided into the upper, the middle and the lower clivus. Extracranial soft tissue landmarks and bony landmarks were presented. Intradural landmarks of the upper clivus were the interpeduncular cistern, posterior cerebral artery, posterior communicating artery, superior cerebellar artery, cranial nerve III and cerebral peduncle; intradural landmarks of the middle clivus were the prepontine cistern, basilar artery, cranial nerve VI and pons; intradural landmarks of lower clivus were premedullary cistern, vertebral artery, cranial nerve XI and medulla oblongata. Surgical routes to the clivus were the upper clivus approach, middle clivus approach, lower clivus approach and panclival approach.

An understanding of the complex anatomy of the clivus is paramount for surgically dealing with the disease involved clivus and adjacent region.