Article
What is the role of the endoscope during microsurgical removal of vestibular schwannomas?
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Published: | June 4, 2012 |
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Objective: During vestibular schwannoma surgery, the endoscope view may be important for finding remnant tumor tissue and visualizing opened mastoid air cells. The aim of this study is to observe the importance of the endoscope in microsurgery of these tumors and its potential risks.
Methods: Between February 2003 and September 2008 102 Patients were operated on vestibular schwannomas using the microscope. During surgery the presence of residual intrameatal tumor and opened mastoid cells was evaluated with a neuroendoscope. Electrophysiological monitoring assessing the cochlear and facial nerve function was performed during surgery. The risks and benefits of this technique were evaluated and discussed.
Results: In 13 cases out of 102 remaining intrameatal tumor was found after microscopic resection and endoscopic inspection of the internal auditory canal. Endoscopy was considered to be useful in 73% of the cases, especially in cases with small deep intrameatal tumors and of high-positioned jugular bulbus. Altogether, 19 Patients had a worsening on the auditory evoked potential waves during the electrophysiological monitoring. Seven out of 19 Patients developed this worsening after the introduction of the endoscope and when the tumor resection was already completed. In four cases the auditory evoked potential deficit was permanent, and the Patients were deaf after surgery.
Conclusions: Endoscopy in microsurgical removal of vestibular schwannomas was considered to be useful, especially in cases with small deep intrameatal tumors and of high-positioned jugular bulbus. The inspection of the fundus of the internal auditory canal permits the identification of eventual rest tumor. Visualization of opened air cells could prevent cerebrospinal fluid leak. The risk of using this instrument, especially with angulated lenses in such delicate area should not be forgotten. The introduction of the endoscope in the cerebellopontine angle should be always carefully performed under microscopic overview.