Occipital emissary foramina in human skulls: an anatomical investigation with reference to surgical anatomy of emissary veins

Abstract

AIM: The objectives were to find the incidence and topography of the occipital emissary foramina in skulls of South Indian Region. MATERIAL and METHODS: In the present study, 78 dried adult human skulls were examined. They were analyzed for the gross incidence and position of the occipital emissary foramen. The observations were made in the squamous part of the occipital bone from the posterior margin of the foramen magnum to the external occipital protuberance. RESULTS: From our observations, the occipital emissary foramen was present in 11 (14.1%) skulls. Left sided foramen was observed in 5 cases (6.4%), right-sided foramen in 4 (5.1%) and the median foramen was seen in 2 (2.6%) of the cases. CONCLUSION: The occipital emissary vein is present in a small percentage (14.1%) of cases. It was also demonstrated that its location is variable as to left, right or midline. Its location was closer to the foramen magnum than to the external occipital protuberance in all the specimens. The morphology of this subject is important to the neurosurgeons and plastic surgeons. The knowledge is of importance in suboccipital craniotomies as this foramen transmits the occipital emissary vein and will keep awareness among the surgeons to avoid the excessive bleeding.

Morphology and topography of the parietal emissary foramina in South Indians: an anatomical study

“…The comparison was also done among the different emissary foramina of the South Indian skull, which is given in Table 4 . This was possible by referring our previous reports [ 7 8 9 10 ], which were also from the same South Indian adult skull specimens.…”

“…The present study compared the prevalence of parietal emissary vein with the other emissary veins of the skull from the same South Indian population. This comparison was possible after referring our previous publications [ 7 8 9 10 ] and this comparison is given in the Table 4 . It was observed that the parietal emissary veins have a higher prevalence, which is next to the prevalence of mastoid emissary veins in the South Indian population.…”

“…The emissary foramina are commonly described as the channel for the emissary vein [ 6 ]. There are only a few Indian studies [ 7 8 9 10 ] available in literature about the emissary foramina in the occipital, condylar, mastoid and sphenoid bones; however, the studies about the parietal emissary foramina are not found in the medical literature. This was the stimulus to perform this present investigation from the anatomical specimens.…”

Occipital emissary foramina in human skulls: review of literature and proposal of a classification scheme of the occipital venous anastomoses in the posterior cranial fossa

“…[2][3][4] Reviewing the pertinent literature, it seems that this bony foramen in skull series shows low and quite variable frequency. [5][6][7][8][9][10][11][12][13] Additionally, it is demonstrated with much higher incidence in diagnostic imaging studies. [14,15] With the present study, based on examination of human skulls, and after reviewing the literature, we aimed to explain the discrepancies between the reported incidence of the OEF and OEV, which might help radiologists in diagnosing specific pathologies in the dural sinus system [14,15] and also neurosurgeons performing approaches to the posterior cranial fossa.…”

Evaluation of the Mastoid Emissary Canals with Computerized Tomography in Patients with Chronic Otitis Media

“…[1][2][3] In some individuals, the MEVs establish connections with intra-diploic structures. 1,4 Under normal conditions, blood flow in these emissary veins with valves is slow and generally from the intracranial system to the extracranial system. 5 Chronic otitis media (COM) is a disease that causes ear membrane perforation and recurrent or continuous auricular discharge for more than 3 months.…”