Fig. 3.

Preoperative radiological planning of the contralateral mononostril endonasal approach. Planning was performed using Carestream Image Suite software, with spatially synchronized images. The blue line in (a) indicates the orientation of images (b) and (c). The yellow cross is co-registered across all three images and identifies the pituitary gland (PG). The orange arrow in (a) and (b) indicates the planned surgical trajectory. The cyst creates a natural surgical corridor within the lateral compartment of the cavernous sinus (CS), between the cavernous internal carotid artery (cICA) and the lateral wall of the CS. (c) A CT scan in the bone window is essential for understanding sphenoid sinus (SS) anatomy. In this case, the median septation identifies the sella and thus the midline, while a smaller left septation (better visualized inFig. 6) inserts onto the left ICA prominence. Based on this anatomy, a contralateral transrostral approach to access the left CS can be performed without the need for a complete sphenoidotomy, preserving the right sphenoid sinus.