Is there a relationship between sphenoid sinus types, septation and symmetry; and septal deviation?

In the present study, we investigated whether there is a relationship between sphenoid sinus (SS) types, septation (lobulation) and symmetry; and septal deviation (SD) by multidetector computed tomography (MDCT). Paranasal MDCT images of 202 subjects (131 males, 71 females), between 10- and 88-year-old, were included into the study. SS type (conchal, presellar or sellar), SS symmetry, SS septation (lobulation) and SD were evaluated by MDCT images. In the present study, in both males (83.2 %) and females (85.9 %); and in all age groups (80.4-85.7 %), sellar type sphenoid sinus were more detected. Conchal type was detected in two cases of the males (1.5 %) and none of the females. SS was detected mainly as multi-septated (multi-lobulated) (51.9 % in males and 56.3 % in females; in all age groups as 51.0-56.8 %; and both SD (+) and SD (-) groups as 51.2-56.8 %). In subjects with SD, asymmetric SS was detected in 80.2 %. Whereas in SD (-) subjects, asymmetric SS was detected in 50.6 %. Sellar type SS pneumatization is the most detected type in our cases. Presence of SD was related to the higher SS asymmetry values. In SD (-) subjects, SS was detected as symmetric. Nasal septal deformities such as SD may influence the development of the SS pneumatization and asymmetric septation. For well anatomic orientation of the surgeons, good anatomy knowledge and preoperative detailed examination of the CT scans are very important.

Risky anatomical variations of sphenoid sinus and surrounding structures in endoscopic sinus surgery.

PURPOSE: This study aimed to examine the relationship between the sphenoid sinus (SS) and surrounding vital structures such as the internal carotid artery (ICA) and optic nerve canal (ONC) as well as the types of attachment of the sphenoidal septa onto these structures. METHODS: In total, 230 computed tomography (CT) scans were reviewed to study the type of sphenoid sinus pneumatization (SSP), the protrusion and dehiscence of the ICA and ONC, the relationship between the sphenoidal septa and surrounding vital structures as well as pterygoid recess pneumatization (PRP). RESULTS: The most common SSP was sellar type (58.7%). The rates of protrusion and dehiscence of the ICA were 26.3 and 0.4%, and for the ONC, they were 13 and 1.5%, respectively. The ICA and ONC were most protruded and dehiscent in more extensive SSP. In 21.6% of patients, the intersphenoidal septa (IS) were attached to the wall of the ICA and in 8.6% they were attached to the wall of the ONC. The attachment of IS to the ICA correlated statistically significantly (p < 0.0001) with protrusion of the ICA. Accessory septa were detected in 30.4% of cases with various sites of attachment. CONCLUSION: To reduce the risk of injury and complications during endoscopic sinus surgery (ESS), surgeons should consider using CT to identify possible bulging and dehiscence of the ICA/ONC and their relationship to the extent of SSP and also to establish the presence of deviation of the sphenoid septum, and the presence of accessory septa.