Advantages of Using Endoscopes in Translabyrinthine and Middle Fossa Approach in Vestibular Schwannoma Surgery

Introduction: In vestibular schwannoma surgery the view into the cerebellopontine angle (CPA) is limited by nonresectable bony edges. In particular, the group of cerebral nerves IX to XII is out of complete sight. With microscopes a bright and magnified but only straight view is possible, while an angled view is necessary to detect tumor rests or bleeding.

Material and Methods: In 6 cases of translabyrinthine and in 12 cases of middle fossa approaches for vestibular schwannoma surgery, endoscopes were used to control the operation site in the internal acoustic meatus and in the CPA. Wide angled 0-, 30-, 45- and 70-degree optics were used. All findings were recorded with a digital imaging and archiving system.

Results: In all cases an extended view was achieved. The control over tumor resection was completely possible. In 3 cases a permanent bleeding from arachnoidal vessels could be detected and stopped. In 5 cases small tumor rests were detected. The extent of bony edges could also be detected, so the opening of bone was possible in a more secure matter. Anatomical structures, especially the brainstem and nerves in the CPA, could be seen completely after opening the porus acusticus internus and the resection of tumor.

Conclusions: The use of endoscopes in vestibular schwannoma surgery has offered additional views into the CPA to control the result of tumor resection and the anatomical situation. It should be emphasized to prevent residual tumors and bleedings into the cerebrospinal fluid system.