Letters to the Editor
To the Editor: A way to identify horizontal portion of the facial nerve is fittingly described in the article by Vinidh Paleri and Carl Watson titled “Objective Assessment of the Perineural Vascular Plexus as a Landmark for the Horizontal Part of the Facial Nerve in Middle Ear and Mastoid Surgery” (1). Two problems in this article must be mentioned. First, the incidence of facial nerve dehiscence in the literature is reported to be as high as 56% in a histopathologic study (2) and 33% in a surgical analysis (3). Searching for vascular plexus of the nerve in cases of cholesteatoma and particularly granulation tissue in the region of the dehiscence will not greatly help us in identifying the nerve and not to injure it.
On the other hand, as we have many cases of cholesteatoma in our country, we have lots of cases in which the vascular plexus is in its place and which illustrate the horizontal portion of the fallopian canal; however, the nerve has a protruding portion specially over the oval window region and still one can see its canal with its vessels in place. Therefore, if one removes cholesteatoma or granulation from this place just by emphasizing on the vessels which still could be seen in the fallopian canal, one may traumatize the protruding portion of the nerve.
Thus, it is inferred that while the facial nerve landmarks and this vascular landmark may help in surgery, still it is the surgeons' experience, carefulness, and delicate operation that makes the operation safe and sound.
Department of Otolaryngology-Head and Neck Surgery, Shaheed Beheshti University of Medical Sciences, Tehran, Iran
1. Paleri V, Watson C. Objective assessment of the perineural vascular plexus as a landmark for the horizontal part of the facial nerve in middle ear and mastoid surgery. Otol Neurotol
2. Moreano EH, Paparella MM, Zelterman D, Goycoolea MV. Prevalence of facial canal dehiscence and of persistent stapedial artery in the human middle ear: a report of 1000 temporal bones. Laryngoscope
3. Selesnick SH, Lynn-Macrae AG. The incidence of facial nerve dehiscence at surgery for cholesteatoma. Otol Neurotol