Morphological Variability of the Sphenoid Sinus Septations

Abstract

Introduction

The sphenoid sinus (SS) is a highly variable, anatomically complex structure located at the skull base and intimately related to critical neurovascular elements, including the internal carotid artery and optic nerve. A precise understanding of its internal septation patterns is essential for safe surgical navigation during transsphenoidal and skull base approaches.

Aim

The aim of this study is to describe and classify the morphological variability of SS septations (SSs) using high-resolution computed tomography (CT), emphasizing their number, orientation, and relationships to key anatomical landmarks.

Methods

A retrospective review of 253 adult CT and CT angiography scans (129 males, 124 females; mean age 51.7 ± 15.0 years) was performed. Septations were assessed for number, completeness, orientation, and attachment sites. Sinus morphology was further categorized as simple or complex based on septation symmetry and configuration.

Results

The mean number of septations was 1.68 ± 0.95. A single septum was present in 53% of cases, two in 29.6%, and three or more in 15%. Most septations were vertical (88.1%) and eccentric (57.7%). Simple configurations predominated (69.6%), whereas complex morphologies accounted for 29.2%. No significant sex-related differences were identified (p = 0.937). Septal attachment to the carotid canal occurred in 49.8% of cases (unilateral 34.0%, bilateral 15.8%), whereas attachment to the optic canal was found in 9.5%. Deviation toward the sellar wall was significantly associated with complex morphology (p = 0.015).

Conclusion

SSs display notable interindividual variability, typically presenting as one or two vertical, eccentric septa frequently attached to the carotid canal. Owing to their proximity to vital neurovascular structures, detailed preoperative CT evaluation is imperative for precise surgical orientation and the safe execution of transsphenoidal and skull base procedures.

Keywords

sphenoid sinus - septation - variation - sphenoidal surgery

Data Availability

Please contact the authors for data requests.

Contributors Statement

P.P.M. led the conceptualization and project development and contributed to data collection, analysis, manuscript review and editing, and final approval of the version to be published. G.T. performed data and statistical analyses, drafted the original manuscript, and approved the final version. C.G. contributed to data collection and analysis, manuscript review and editing, and final approval. G.S. participated in data analysis, manuscript review and editing, and final approval. M.P. provided supervision, contributed to data analysis and original draft preparation, and approved the final version.

Ethical Approval

The General Hospital of Nikaia-Piraeus Ethics Committee approved the imaging study (number of approvals: 56485, date of approval: November 13, 2024). The research was conducted ethically following the Code of Ethics of the World Medical Association (Declaration of Helsinki).

Publikationsverlauf

Eingereicht: 09. September 2025

Angenommen: 16. Dezember 2025

Accepted Manuscript online:
19. Dezember 2025

Artikel online veröffentlicht:
30. Dezember 2025

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