抄録
We report the experience of drill-off of the endostosis of the posterior clinoid process in clipping the aneurysms around the basilar bifurcation. Elimination of the endostosis is effective in cases with aneurysms around the basilar bifurcation, which is accessible in the pterional approach, and with endostosis of the posterior clinoid process, which obstructs access to the interpeduncular cistern. For the meticulous drilling procedure, it is necessary to make a wide working space by thorough opening of the sylvian fissure. It is also important not to use protectors such as cottonoid and multiple rubber dams, which can be caught in the drilling bar.
