Surgical anatomy of anterior and retrofacial approaches to sinus tympani.
OBJECTIVE
To define anatomic parameters indicating or limiting the use of anterior and retrofacial accesses to sinus tympani (ST).


METHODS
Anatomic study (30 temporal bones).


METHODS
The profundity of the ST, the distance between the sigmoid sinus and facial nerve (SS-F), the distance from posterior semicircular canal to the facial nerve, and the capacity of adequate visualization of the ST.


RESULTS
Sinus tympani depth was significantly smaller (<or=0.83 mm) when visualization was possible by anterior approach. Measurements of SS-F greater than 10 mm and ST profundity greater than 1 mm indicated accessibility of posterior approach.


CONCLUSIONS
Posterior extension of ST and the relation SS-F were the most important measures when the surgical accessibility of the ST was envisaged. Sinus tympani can be accessed through an anterior approach when the depth is less than 1 mm or by means of a posterior access when profundity is 1 mm or greater and the relation of SS-F is 10 mm or greater.
Cesário de Abreu
Carlos Eduardo
CE
Federal University of São Paulo (UNIFESP), Brazil.
Mendonça Cruz
Oswaldo Laércio
OL
D005154:Facial Nerve / Q000033:anatomy & histology*; D006801:Humans; D013506:Otologic Surgical Procedures / Q000379:methods*; D012665:Semicircular Canals / Q000033:anatomy & histology / Q000601:surgery; D013701:Temporal Bone / Q000033:anatomy & histology / Q000601:surgery*; D014432:Tympanic Membrane / Q000033:anatomy & histology* / Q000601:surgery*