Trans-sphenoidal approach is the standard surgical method for pituitary adenomas. It is important to determine its variations and relationship to adjacent vital structures. The purpose of this study was to investigate the prevalence of variations of the sphenoid sinus on paranasal CT in Turkish population and their importance in surgical planning. We reviewed the paranasal CT examinations of 228 patients retrospectively that were performed between 2010-2014. Sphenoid sinus dimensions, wall thickness, structure of quantity the intersinus septum, interval between optic channel, pneumatization and variations of the sphenoid sinus was assessed. The determined anatomical variations and the their prevalence were demonstrated as follows: pneumatization of the pterygoid process in 78 patients (34%), pneumatization of the anterior clinoid process in 32 patients (14%), vidian canal protrusion in 21 patients (9.2%), vidian canal dehiscence in 22 patients (9.6%), optic nerve protrusion in 30 patients (13.1%), optic nerve dehiscence in 15 patients (6.6%), maxillary nerve protrusion in 59 patients (25.9%), maxillary nerve dehiscence in 5 patients (2.2%), carotid artery protrusion in 29 patients (12.7%), carotid artery dehiscence in 6 patients (2.6%), onodi cell (Figs. 2 and 3) in 13 patients (5.7%). Presence of multiple septations was found in 81 patients (35.6%), a single intersinus septum was found in 128 patients (56.1%) and no septation was found in 19 patients (8.3%). Preoperative recognition of sphenoid sinus variations with paranasal CT maybe beneficial so that the limits of dissection can be identified and the complications can be avoided during the trans-sphenoidal approach.
Keywords: Sphenoid sinus, pneumatization, intersinus septum, trans-sphenoidal approach.
