Abstract

Sphenoid sinus is situated in midline within the sphenoid bone in the base of skull posterior to the ethmoid air cells. This sinus is in close proximity with optic nerve (ON), internal carotid artery (ICA), pitutary gland (PG) and cavernous sinus (CS). Sphenoid sinus approach is commonly used for endoscopic pituitary gland surgery and other skull base procedures too. Radiological evaluation of this sinus is of paramount importance before attempting any such surgical procedures.

Aim: This study was designed to evaluate sphenoid sinus and surgical structures in sphenoid sinus region in Indian population with help of radiological imaging.

Materials and Methods: Retrospective analysis of non contrast computed tomograms (NCCT) of 140 patients was performed. Parameters measured were type of pneumatisation, septa number and attachment, presence of lateral recess (LR) and carotico-optic sinus (COS), dehiscence of bony lamella and presence of onodi cell (OC). All scans were reviewed by a team of otorhinolaryngologist and radiologist.

Results: The study group consist of 140 individuals (85 Males and 35 Females). The mean age of patients was 33.45 year for males and 37.36 year for females. Most common type of septa found was complete single septa and sellar pneumatisation, Lateral recess was present in 48.57% and Carotico-optic recess in 24.28% of cases; onodi cell was least frequently encountered in 5% of NCCT scans only.

Conclusion: Variation are common in sphenoid sinus and pre operative radiological assessment of complex relations of sphenoid sinus septa with important structures present in vicinity of this sinus is of paramount importance before attempting any endoscopic surgery in this area.

Keywords: Sphenoid sinus, radiological imaging, computed tomography,  endoscopic sinus surgery, internal carotid artery, optic nerve, sella turcica.