The Septation of the Sphenoidal Air Sinus. A Cadaveric Study

SUMMARY: The purpose of this study was to investigate the sphenoidal sinus septation in a select South African population, and document the relation of the number and location of the septa to the structures intimately related to the sinus. The intersinus and intrasinus septa of the sinus, the number and attachments of the septa were recorded from forty five cadaveric head specimens. The sphenoidal sinus intersinus septa were recorded as follows: Type 0 (absent septum) in 7.5 %, Type 1 (single septum) in 65 % and Type 2 (double septa) in 22.5 % of cases. The incidence of intersinus septa deviating to the left was prevalent; hence, the right sphenoidal sinus was dominant. The occurrence of intrasinus septa was observed in 93.3 % of cases, with a higher prevalence in males. The intrasinus septa formed cave like chambers on the sinus walls in 65.6 % cases. Incidences of the intersinus septa attaching to sella turcica (ST) (46.25 %) were prevalent compared to cases where they attached to the internal carotid artery (ICA) (6.25 %), maxillary (MN) (1.25 %) and vidian (VN) (1.25 %) nerves. However, the intrasinus septa attached more to the ICA (52.63 %) compared to their attachment to the other neurovascular structures (ST - 26.32 %; MN - 5.36 % and VN - 2.63 %). Surgeons need to be aware of the complex anatomical variations of the sphenoidal sinus septation when performing endoscopic endonasal transsphenoidal surgeries.