Commentary

The authors reported an anatomical study based on 10 adult cadaveric heads. The clivus was exposed through an extended subfrontal approach, and the additional exposure gained with endoscopic supplementation after a maximum microsurgical exposure was measured. The results indicated that an additional area, ranging from 34.9% to 174% more bone, can be exposed by the addition of the endoscope. The authors also concluded that the percentage of increased area after endoscopy (Δperc) is greater in the region of the vertical segment of the internal carotid arteries (ICAs) where these arteries are closer together. They rightly advocate drilling only when the drill burr can be visualized, and their study appears to demonstrate better visualization of the burr in “blind angles” with the endoscope.

This study confirms what is known intuitively about the capabilities of the endoscope and joins a rapidly growing volume of literature demonstrating this capability. It has yet to be demonstrated whether endoscopy can be performed safely in a patient where visualization would require both meticulous hemostasis to prevent obscuration of the lens and careful control of the drill when working behind the ICA and other critical structures. Also not yet demonstrated is an improvement in the length of survival of patients with extensive giant skull base chordomas. To remove such a lesion completely to cure a patient using today's technology still seems a Herculean and almost impossible task. If the authors use this approach in a clinical setting, a report of their experience would be interesting.