Background: Sphenoid sinuses are surrounded by many crucial structures. During endoscopic sinus surgery or the transsphenoidal procedures, complications as arterial bleeding and visual affection can be caused by nearness of internal carotid artery (ICA) and cranial nerves to sphenoid sinuses.
Objective: to study the important structures in sphenoid sinuses and their variations by multi slices computed tomography (MSCT) to guide otorhinolaryngologists to avoid injury of vital structures.
Methods: MSCT of paranasal sinuses was done for all included subjects to get fine sphenoid sinuses anatomical details using axial, coronal and sagittal images.
Result: Within included 100 adult individuals (200 sphenoid sinuses); we found pneumatization of anterior clinoid process (ACP), pterygoid process (PP), and greater wing of sphenoid (GWS) in 16%, 30%, and 30% of patients. We found protrusion of ICA, optic nerve (ON), MN and V in 40%, 36%, 25% and 28% and their dehiscence in 30%, 31%, 14% and 37%. There was a highly significant relationship between ON protrusion and ACP pneumatization, ICA protrusion and ACP pneumatization, MN protrusion and GWS pneumatization and VN protrusion and PP pneumatization. There were significant associations between GWS pneumatization and MN protrusion and between PP pneumatization and VN protrusion.
Conclusion: anatomical sphenoid sinuses variations are usual with high ICA and ON protrusion and dehiscence prevalence. ICA, ON and/or VN protrusion is powerfully related to ipsilateral nearby pneumatization. MN dehiscence and protrusion were less common. Thus, coronal CT is essential in pre-surgical evaluation to minimize vascular and neural injuries.