Endoscopic skull base surgery requires “retooling” on the part of the skull base surgeon. For otolaryngologists or head and neck surgeons training in the era of endoscopic sinus surgery, acquisition of endoscopic skills occurs in conjunction with training in external approaches to the cranial base. Acquisition of endoscopic skills has been more problematic for the neurosurgeon who rarely uses the endoscope in other surgical procedures. We have suggested training guidelines that build incrementally for teams of otolaryngologists and neurosurgeons performing endoscopic endonasal skull base surgery.

Endonasal skull base procedures are categorized into five levels based on their technical difficulty, potential risk to neural and vascular structures, extent of intracranial dissection, and type of pathology. Mastery of each level is recommended before proceeding to the next level ¹⁾.