[Topographic anatomy of the asterion].
BACKGROUND
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.


METHODS
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.


RESULTS
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.


CONCLUSIONS
The burr hole for posterolateral approaches to the posterior fossa must be located below and behind the asterion.
Martinez
F
F
Facultad de Medicina y Hospital de Clínicas Dr. Manuel Quintela. Montevideo. Uruguay.
Laxague
A
A
Vida
L
L
Prinzo
H
H
Sgarbi
N
N
Soria
V R
VR
Bianchi
C
C
D000328:Adult; D002102:Cadaver; D003388:Cranial Fossa, Posterior / Q000033:anatomy & histology* / Q000601:surgery; D003392:Cranial Sinuses / Q000033:anatomy & histology*; D006801:Humans; D019635:Neurosurgical Procedures; D012886:Skull / Q000033:anatomy & histology; D013499:Surface Properties