Extradural approach to the upper clivus. A 45-degree endoscope is used to improve visualization of the upper clivus. When elevating the sellar dura, great care should be taken to avoid damaging the posterior lobe of the pituitary gland, because it has a thinner layer of dural protection. The dorsum sella has been completely removed but the posterior clinoids still remain. (Image courtesy of JC Fernandez-Miranda)