The sinus tympani lies medial to the pyramid, stapedius muscle and vertical part of facial nerve.
Baki et al studied the endoscopic anatomy of the sinus tympani and found that the sinus tympani is bounded laterally by a constant ledge of bone anterior to the facial nerve.
Confluent Shape- An incomplete ponticulus is present and the sinus tympani is confluent to the posterior sinus.
Longterm results with operated sinus tympani
The paint mark in the sinus tympani was placed by reversing the orientation of the temporal bone, which allowed for better visualization of the posterior tympanic cavity.
More notable is the finding that ICWM with otoendoscopy was superior to CWDM in providing visualization of the sinus tympani.
Moreover, several authors have determined that the epitympanum, sinus tympani, and middle ear cavity are areas of high risk for recurrent disease.
Dimensions of the sinus tympani
and its surgical access via a retrofacial approach.
Removal of the middle or inferior portion of the posterior canal wall can increase the amount of exposure to the hypotympanum and to the region of the sinus tympani.
Indications for a second-look procedure include (1) excessive bleeding or inflammation that prevents full visualization of cholesteatoma, (2) a suspicion that cholesteatoma has been only incompletely excised, especially in the sinus tympani, on the facial nerve, or on the ossicular chain, and (3) reconstruction of the ossicular chain in a less-inflamed environment.