ABSTRACT
Ten cadaveric heads fixed and injected were dissected in the operative position. An
enlarged subfrontal approach was adopted. The clival bone was drilled as much as possible
under direct microscopic vision. Dissection in blind angles was avoided until the
clival dura was exposed. The rigid 4-mm endoscope (angled 0 degrees and 30 degrees)
was secured in a holder so the surgical cavity could be inspected. The residual bone
was drilled under endoscopic visualization. The amount of bone removed was measured
and compared with that removed under microscopic view. Blind angles in both microscopic
and endoscopic views were recorded. The additional area of clival bone removed under
endoscopic visualization compared with microscopic visualization was 467 mm2 (range, 176 to 753 mm2; standard deviation, 208.8 mm2).The amount of additional bone removed under endoscopy was inversely and significantly
related to the minimal distance between the vertical segment of the two cavernous
carotid arteries (p = 0.04). The endoscope is of great value in the removal of clival
bone through the extended subfrontal approach. Its use improves the visualization
of angles that are blind under the microscope.
KEYWORDS
Anatomy - clivus - endoscopy - microsurgery - skull base