JOURNAL ARTICLE

Preservation of labyrinthine structures while drilling the posterior wall of the internal auditory canal in surgery of vestibular schwannomas via the retrosigmoid suboccipital approach

Amey Savardekar, Takashi Nagata, Kraiyot Kiatsoontorn, Yuzo Terakawa, Kenichi Ishibashi, Takeo Goto, Kenji Ohata
World Neurosurgery 2014, 82 (3-4): 474-9
24560708

OBJECTIVE: To describe a new technique for safe drilling of the posterior wall of the internal auditory canal (IAC), in which the intact posterior lip of the internal auditory meatus is used as a fixed intraoperative reference point to preserve the integrity of labyrinthine structures.

METHODS: The retrosigmoid suboccipital approach was used to operate on 6 cases of vestibular schwannomas (Koos grade I and II), with preserved hearing. On a preoperative high-resolution computed tomography scan, a line starting 2 cm lateral to the lateral edge of the sigmoid sinus on the dura mater and directed tangential to the posterior semicircular canal or common crus was identified to intersect the posterior wall of the IAC. Drilling was carried out at a measured angle to the posterior petrous wall for meticulously measured distances, taking the intact posterior lip of the internal auditory meatus as a fixed bony point.

RESULTS: In the 6 cases, the mean length of the posterior wall of the IAC measured on the preoperative high-resolution computed tomography scan was 10.79 mm±1.87. By using our technique, the percentage of total length of the posterior wall of IAC drilled was 75.3%±20.5%. No injury to the posterior semicircular canal or common crus was observed intraoperatively. Total excision was performed in 5 patients, and near-total excision was performed in 1 patient. Functional hearing was preserved in all patients; testing was done 1 month after surgery.

CONCLUSIONS: Adequate drilling of the posterior wall of the IAC could be achieved, and tumor excision with hearing preservation was obtained by meticulous intraoperative planning and measurements based on preoperative computed tomography scanning and by keeping the intact posterior lip of the internal auditory meatus as a landmark for safe drilling.

Full Text Links

Find Full Text Links for this Article

Discussion

You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read
24560708
×

Save your favorite articles in one place with a free QxMD account.

×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"