gms | German Medical Science

Objective: To evaluate the feasibility and value of the endoscope-assisted technique in the microsurgical treatment of T1 and T2 vestibular schwannomas (VS) via the retrosigmoid approach.

Method: From May 2011 to October 2013, 24 patients with a T1 or T2 VS were operated in endoscope-assisted technique through a retrosig approach. Rigid endoscopes with 30° optics were used.

Results: The endoscopic view was used for inspection of the most lateral part of the inner auditory canal (IAC), evaluation if the semicircular canals were accidentally opened, removal of tumour remnants and sealing of opened air cells at the posterior lip of the IAC. No case of thermal or mechanical injury to neurovascular structures occurred. Using that technique no postoperative cerebrospinal fluid fistula occurred. The endoscope confirmed the completeness of the tumor resection as verified in the MRI follow-up. Anatomic preservation of the facial nerve and cochlear nerve was achieved in 24 (100%) cases. Hearing function was preserved postoperatively in 9 (75%) patients out of all 12 patients who showed preoperative serviceable hearing.

Conclusions: Adjunctive use of rigid endoscopy during the retrosigmoid approach can provide more information to evaluate neurovascular relationship, the tumor residual and opened air cells than was possible with microscopy alone, ensuring completed VS removal and neurological function preservation. In the future, tailored endoscopic equipment and special training will optimize the outcome of endoscope-assisted microsurgical treatment of VS.