Anatomical Variations of the Sphenoid Sinus and Nearby Neurovascular Structures Seen on Computed Tomography of Black Africans.

Background: To describe the relationship of optic nerves and internal carotid arteries to sphenoid sinus using Computerized Tomography (CT) in a black African population.
Methods: We retrospectively reviewed both the coronal and axial CT images of the paranasal sinuses and brain of 110 patients which were obtained for head and neck diseases other than malignancies, nasal polyps and craniofacial trauma using computer workstation with Clearcanvas software. All scans were evaluated on both soft tissue and bone windows for the identification of protrusion of optic nerve (ON) and internal carotid artery (ICA) into the sphenoid sinus, pneumatisation of the anterior clinoid process (ACP) and position of the sphenoid septum.
Results: Forty two (38.2%) cases have ON protruding into the sphenoidal sinus and ON wall dehiscence occurred in 15(13.6%). Protrusion of the ICA into the sphenoid sinus was on CT images of 30 (27.3%) patients and dehiscence of bony sphenoidal wall of ICA occurred in 12 (10.9%) patients. The anterior clinoid process (ACP) was pneumatized in 16 (14.5%) cases and sphenoidal septum was absent in 3(2.7%) cases.
Conclusions: Anatomic variations in relationship of sphenoid sinus to ON and ICA are seen on CT examinations in black Africans population. The endoscopic head and neck surgeons managing black Africans should be aware of these varied relationships and ensure a detailed pre-operative review of the CT scans to avoid the potential risks of blindness, uncontrollable haemorrhage and death that may attend anatomically uninformed sphenoidal surgeries.