Occipital emissary foramina in adult human skulls and their clinical implication

Abstract

Background and Aims: Occipital emissary veins are important sources of bleeding during skull base surgeries like suboccipital craniotomies. To prevent such complications it is important to know the topography and incidence of occipital emissary foramina hence the present study aims to find the incidence and location of occipital emissary foramina in adult human skulls of Indian origin. Materials and methods: One hundred human skulls from the collection of Department of Anatomy Mahatma Gandhi Medical College and Research Institute, Pondicherry and other medical colleges in and around Pondicherry were evaluated. The bones were examined for incidence of occipital emissary foramina. Number of emissary foramina and their distance from the margin of foramen magnum were noted. The patency of the foramina was confirmed by passing a probe through it. Results: Out of the 100 human adult skull bones examined 14(14%) of them showed patent occipital formina. Six of these foramina were present on the left side and six on the right side of midline. Double occipital foramina were seen in two skulls (2%). All the foramina were in proximity to foramen magnum than to the external occipital protuberance. The average distance of the occipital emissary foramina from the margin of foramen magnum was 1.13cm on the left side and 1.10cm on the right side. Conclusion: The present study has shown that the occipital emissary foramina occur at a higher frequency than what has been described earlier in literature.

Keywords

• double foramina
• occipital condyles
• external occipital protuberance
• suboccipital