Agenesis of the sphenoid sinus and a single sphenoid sinus: a computed tomography anatomical evaluation

Sphenoid sinuses are pneumatic spaces within the body of the sphenoid bone. Their development begins in the prenatal life and continues until the adulthood. Agenesis of the sphenoid sinuses is a situation in which they are undeveloped. On the other hand, a single sphenoid sinus lacks the presence of the main septum, leading to the formation of a single antrum. Contemporary use of transnasal transsphenoidal approaches for the pituitary surgery, as well as functional endoscopic sinus surgery urges medical professionals to be well acquainted with the aforementioned variant.

Paranasal sinuses of 300 patients (150 females, 150 males) were evaluated using computed tomography, without the use of contrast medium. Inclusion criteria involved absence of any identifiable pathology within the sphenoid sinuses and age over 18 years. Subgroup analysis involved probing for potential sources of heterogeneity, namely gender.

In the whole research material of 300 patients, agenesis of the sphenoid sinuses was noted in 1% of the patients. No statistically significant differences were noted between the absence of the sphenoid sinuses and gender (p = 0.999). A single sphenoid sinus was found in 0.33% of the patients. There were no statistically significant differences found between the presence of fully developed sphenoid sinuses and gender (p = 0.498).

Both agenesis of the sphenoid sinuses and a single sphenoid sinus are rare anatomical variants. Adequate planning for transsphenoidal surgeries with preoperative medical imaging is of essence in order to perform a safe and quality procedure.