Fig. 4.

The transcanal endoscopic transpromontorial approach: on the left, the schematic drawing shows the surgical route from the external auditory canal to the fundus of the IAC through the promontory (black arrow); on the right the CT Scan in coronal view shows the working area, and the bony removal (dotted area) which may be performed under this approach through the promontory, removing the cochlea and the vestibule, reaching the fundus of the IAC (from Marchioni et al., 2013 ⁵, mod.).