Accessory Foramina Presence Significantly Narrows the Jugular Foramen: Anatomical Study with Potential Neurosurgical Significance

Abstract

Introduction

The jugular foramen (JF) is a critical anatomical structure that houses the lower cranial nerves (IX, X, and XI), making it a key focus in neurosurgical procedures. Variations, such as ossified dural septations within the JF, can significantly impact surgical outcomes. The present study investigates the incidence and impact of these ossifications on JF morphometry, providing insights crucial for surgical planning and execution.

Materials

We analyzed bilaterally 120 adult dried skulls to assess the presence of accessory foramina (AF), proposing that these represent ossified dural septations. Morphometric measurements of the JF, including height and width, were taken in both cases with and without AF with the use of digital caliper. A thorough literature review was conducted to correlate the findings with clinical implications, and statistical analyses were used to determine significant morphological differences.

Results

A complete AF was identified in 2.92% of skulls and an incomplete one in 0.42%. Ossified dural septations were associated with significantly reduced JF height and width. This reduction may hinder intraoperative manipulation, especially of the lower cranial nerves, increasing the potential for complications.

Conclusion

The findings underscore the need to recognize JF variants, especially ossified septations, in neurosurgical practice. These variants can complicate surgical approaches to the skull base, highlighting the need for careful preoperative assessment. Future studies are warranted to explore the clinical ramifications of these findings, particularly to patient outcomes in skull base surgeries.

Keywords

accessory foramen - infratemporal fossa approach - jugular foramen - variation - neurosurgical anatomy - ossification - dural septation - skull base - surgical planning

Ethical Approval and Consent to Participate

The skulls belonged to the Department of Anatomy, School of Medicine, National and Kapodistrian University of Athens. The research was conducted ethically following The Code of Ethics of the World Medical Association (Declaration of Helsinki).

Authors' Contribution

G.Tr., S.L., R.G., and M.P. were responsible for the conceptualization of the study. Data collection was carried out by G.Tr., I.P., P.P., G.Ts., and M.P., while data analysis was performed by G.Tr., S.L., R.G., Ł.O., N.Z., and M.P. The manuscript was written by G.Tr., I.P., S.L., R.G., and M.P., and subsequently reviewed and edited by P.P., Ł.O., G.Ts., N.Z., and M.P. Statistical analysis was conducted by G.Tr., with M.P. providing supervision throughout the project. All authors approved the final version of the manuscript.

Publication History

Received: 24 December 2024

Accepted: 12 April 2025

Accepted Manuscript online:
15 April 2025

Article published online:
30 April 2025

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