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

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 and Methods: 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.