Anatomical Study of the Endonasal Endoscopic Approaches to the Skull Base

Introduction: Our work seeks to demonstrate the anatomical possibilities and limits of endonasal endoscopic approaches. Detailed knowledge of the anatomy of the rhinosinusal compartment and of the skull base is a prerequisite to practicing the surgical treatment of pathologies involving these regions. The anatomical dissection, performed with endoscopic technique, is an indispensable tool that allows a surgeon to acquire real anatomical knowledge, which is not mediated by schemes, and to obtain adequate skill and relative confidence with the surgical technique. The aim of this work was to focus on the main anatomical landmarks for and the risks of the surgical technique.

Material and Method: Our work is an anatomical laboratory study on the limits and risks of the different endoscopic approaches. We present a schematic classification of indications and contraindications for the use of each approach according to the type and location of pathology and the relationship with nearby anatomical structures. The dissection was performed on 3 specimens that had previously been arterially injected. We used 0-, 30- and 45-degree angle optic systems with endoscopic dedicated instruments to make a precise analysis of the surgical limits of each approach in relationship with the instruments.

Results and Discussion: Using the endoscopic technique through the endonasal approach offers, to a group of selected cases, a valid alternative to traditional approaches, including not only sellar and parasellar pathology but also anterior and posterior skull base lesions, down to the odontoid along the midline. At the same time, development of reconstructive techniques provides the possibility to extend the indication of endoscopic endonasal surgical treatment to intradural midline lesions.