This otoendoscopic photograph shows the near total tympanic perforation and mesotympahnic structures, including the round window niche, the pyramidal process with stapedial muscle tendon, the facial nerve, the cochleariform process
, and ossicular chain.
It runs posterior-superior to the cochleariform process
, superior and lateral to the oval window, and then inferior to the lateral semicircular canal.
The lesion had extended from slightly below the level of the pyramidal process to just anterior to the cochleariform process
; it did not extend below the level of the umbo.
A second plaque of tympanosclerosis was seen medial to the neck of the malleus, bridging the gap between it and the cochleariform process
and extending to the chorda tympani nerve.
They include the absence of the foramen spinosum on the affected side and the enlargement of the proximal tympanic segment of the facial nerve canal adjacent to the cochleariform process
The purpose of this article is to describe a fast and safe technique to expose the geniculate ganglion and the labyrinthine portion of the facial nerve in two structures of the middle ear: the cochleariform process and the tympanic portion of the facial nerve.
The surgeon opened a small hole with a diamond bur and identified the cochleariform process and the adjacent segment of the facial nerve (figure 4).
The malleus and the cochleariform process were identified without difficulty, and no manipulation of the ossicular chain was needed to obtain a direct view of the second portion of the facial nerve.
The surgical technique involves exposure of the geniculate ganglion, the greater petrosal nerve, and the facial nerve from the cochleariform process
to the cerebellopontine angle via the middle cranial fossa approach.