A Computed Tomography (CT)-Based Observational Study of Anatomical Variations in the Sphenoid Sinus: Implications for Surgical Planning and Patient Outcomes

Introduction: The sphenoid sinus (SS), a paired paranasal sinus located within the sphenoid bone, is crucial in various physiological and pathological processes. Its anatomical variations are of significant interest in clinical practice, particularly in otolaryngology, neurosurgery, and radiology. This study aims to determine the anatomical variations of the SS and related structures using computed tomography (CT).

Materials and methods: An observational study was conducted at a tertiary care center. The study included 300 patients aged 7-70 who underwent CT brain scans. Exclusions included prior sinonasal surgeries, tumors, nasal polyposis, recurrent pituitary lesions, head trauma, and past orbital or cranial surgeries. Three-dimensional reconstructions assessed SS dimensions, pneumatization types, and variations in the internal carotid artery and optic nerve.

Results: A study on the types of SSs revealed that the reseller type is the most common, accounting for 45% of cases (135 instances). The sellar type accounts for 36% (110 instances), while the conchal type is the least common, observed in 18.33% of cases (55 instances). A significant association between the SS type and variations between neurovascular structures was seen, which was confirmed using chi-square tests. There was a statistically significant relationship between carotid artery variations and SS, with the normal course being predominant at 200 individuals (73.33%). Approximately 40 cases (13.33%) present with dehiscence through the sinus, while 30 individuals (10%) show close proximity. Other, less common variations are observed in 10 patients (3.33%). Optic nerve variations displayed distinct frequencies, with the normal course prevailing in 250 cases (83.33%). Approximately 30 cases (10%) exhibit close proximity to surrounding structures, while 15 cases (5%) present with dehiscence through the sinus. Other less common optic nerve variations are observed in five patients (1.67%).

Conclusion: Comprehensive knowledge of SS anatomy through CT scans is essential for enhancing surgical outcomes and ensuring patient safety.