Hi;
It appears the endoscope is a requirement for total removal of AN from the lateral 2 - 3 mm. of the IAC. Of course, this would not be the same as Total Endoscopic Removal. I had thought a mirror was employed in Mid Fossa to view the lateral end of the IAC, but see copied here the endoscope is used, at least in hearing sparing surgeries of which Mid Fossa is. The article doesn't mention Mid Fossa, but, I believe the report is regarding that.
Copied from a Pubmed article:
"Endoscopy of the Internal Auditory Canal During Hearing Conservation Acoustic Tumor Surgery
McKennan, Kevin X. M.D.
Abstract
Hearing conservation acoustic neuroma surgery is technically demanding. This is attributable primarily to the formidable anatomic obstacles. The axis of the internal auditory canal (IAC) is oriented at an obtuse angle relative to the posterior petrous ridge. In addition, the labyrinth blocks the view of the lateral 2 to 3 mm of the IAC. These two factors prohibit an unobstructed view of the fundus of the IAC with a standard operating binocular microscope. However, angled rigid endoscopes (30 and 70 degrees) offer excellent views of the lateral portion of IAC. The facial nerve, cochleovestibular nerve, transverse crest, and vertical crest (Bill's bar) can be seen endoscopically. Neuroendoscopic examination is helpful to ensure complete tumor removal in the lateral IAC during acoustic tumor surgery. It is also helpful in visually verifying the continuity of the facial and cochlear nerves at the end of the operation.
(C) 1993, The American Journal of Otology, Inc.
