[Topographic anatomy of the asterion].Neurocirugia (Astur) 2005; 16(5):441-6N
In the surgical approaches to the posterior fossa, the accurate location of the transverse-sigmoid sinus (TS-SS) complex is of great importance. The asterion is a referral landmark to the transverse sinus location.
Twenty-five skulls of adult cadavers were studied. We seek for the relationships of the asterion with: TS location, mastoid emissary vein, suprametal crest and inion.
The asterion was found in 49 cases. In the great majority of cases (87.8%) the asterion was over the TS (72.2% over the sinus proper, 27.8% over the TS-SS transition). The mastoid emissary vein was present in 46 cases, and in 36% we found two veins.
DISCUSSION AND CONCLUSIONS
The burr hole for posterolateral approaches to the posterior fossa must be located below and behind the asterion.