European Journal of Cardiovascular Medicine

Background: The emissary foramina are the small foramina that transmit the valveless emissary veins connecting the extracranial veins with the intracranial veins. Occipital emissary foramina usually transmit the occipital emissary vein; this vein connects the suboccipital venous plexus with the occipital sinus. There are variations in the number and location of these foramina which deserves special importance during surgical procedures. Objectives: To evaluate the number and location of the occipital emissary foramen in dry adult skulls. Materials And Methods: The study was performed on 150 adult dry human skulls of unknown sex available at the department of Anatomy, Adichunchanagiri Institute of Medical Sciences. The occipital bones were observed with the magnifying lens for the presence, number, and location of occipital emissary foramina. The skulls with broken occipital bone were excluded from the study. The presence of foramen was confirmed by passing the probe through it. Results: The occipital emissary foramen was present in 45/150 (30%) skulls. In 2 skulls the foramen was located on the external occipital protuberance. In 2 it was located on the right side of the external occipital protuberance. In 4 it was located on the left side of the external occipital protuberance, in 8 it was bilateral and in 6 it was on the external occipital crest. Rest 23 solitary foramina were near the foramen magnum. Conclusion: The dura mater of the posterior cranial fossa is tightly adherent to the periosteum of the skull and cannot be stripped easily. Due to this reason, there might be a chance of massive intermittent bleeding from the bone or from the dura or from the dural sinus during the surgical procedures of the posterior cranial fossa which has to be taken care of. The knowledge of the presence, number, and location of occipital emissary foramina becomes very essential to avoid unexpected massive intracranial bleeding during neurosurgical procedures.